Inhibitory properties of selected South African medicinal plants against Mycobacterium tuberculosis

Traditional Uses, Pharmacological Activities, and Phytochemical Analysis of Diospyros mespiliformis Hochst. ex. A. DC (Ebenaceae): A Review

Diospyros mespiliformis Hochst. ex. A. DC is widely distributed throughout Africa and around the world. It is utilized ethnobotanically to treat fevers, wounds, malaria, diabetes mellitus, and other diseases. This review aims to provide an exhaustive overview of the traditional uses, pharmacology, and phytochemical analysis of D. mespiliformis, with the objective of identifying its therapeutic potential for further research. Scientific resources, including Google Scholar, Science Direct, Web of Science, Pub Med, and Scopus, were used to find pertinent data on D. mespiliformis. Secondary metabolites tentatively identified from this species were primarily terpenoids, naphthoquinones, phenolics, and coumarins. D. mespiliformis has been reported to demonstrate pharmacological activities, including antimicrobial, antiproliferative, antiparasitic, antioxidant, anti-inflammatory, antiviral, anti-hypersensitivity, and antidiabetic properties. The phytochemicals and extracts from D. mespiliformis have been reported to have some pharmacological effects in in vivo studies and were not toxic to the animal models that were utilized. The D. mespiliformis information reported in this review provides researchers with a comprehensive summary of the current research status of this medicinal plant and a guide for further investigation.

In-silico and in-vitro assessments of some fabaceae, rhamnaceae, apocynaceae, and anacardiaceae species against Mycobacterium tuberculosis H37Rv and triple-negative breast cancer cells

Medicinal plants play a huge role in the treatment of various diseases in the Limpopo province (South Africa). Traditionally, concoctions used for treating tuberculosis and cancer are sometimes prepared from plant parts naturally occurring in the region, these include (but not limited to) Schotia brachypetala, Rauvolfia caffra, Schinus molle, Ziziphus mucronate, and Senna petersiana. In this study, the aim was to evaluate the potential antimycobacterial activity of the five medicinal plants against Mycobacterium smegmatis mc²155, Mycobacterium aurum A + , and Mycobacterium tuberculosis H37Rv, and cytotoxic activity against MDA-MB 231 triple-negative breast cancer cells. Phytochemical constituents present in R. caffra and S. molle were tentatively identified by LC-QTOF-MS/MS as these extracts showed antimycobacterial and cytotoxic activity. A rigorous Virtual Screening Workflow (VSW) of the tentatively identified phytocompounds was then employed to identify potential inhibitor/s of M. tuberculosis pantothenate kinase (PanK). Molecular dynamics simulations and post-MM-GBSA free energy calculations were used to determine the potential mode of action and selectivity of selected phytocompounds. The results showed that plant crude extracts generally exhibited poor antimycobacterial activity, except for R. caffra and S. molle which exhibited average efficacy against M. tuberculosis H37Rv with minimum inhibitory concentrations between 0.25-0.125 mg/mL. Only one compound with a favourable ADME profile, namely, norajmaline was returned from the VSW. Norajmaline exhibited a docking score of -7.47 kcal/mol, while, pre-MM-GBSA calculation revealed binding free energy to be -37.64 kcal/mol. All plant extracts exhibited a 50% inhibitory concentration (IC₅₀) of < 30 μg/mL against MDA-MB 231 cells. Flow cytometry analysis of treated MDA-MB 231 cells showed that the dichloromethane extracts from S. petersiana, Z. mucronate, and ethyl acetate extracts from R. caffra and S. molle induced higher levels of apoptosis than cisplatin. It was concluded that norajmaline could emerge as a potential antimycobacterial lead compound. Validation of the antimycobacterial activity of norajmaline will need to be performed in vitro and in vivo before chemical modifications to enhance potency and efficacy are done. S. petersiana, Z. mucronate, R.caffra and S. molle possess strong potential as key contributors in developing new and effective treatments for triple-negative breast cancer in light of the urgent requirement for innovative therapeutic solutions.

Medicinal Plants as Therapeutic Alternatives to Combat Mycobacterium tuberculosis: A Comprehensive Review

Tuberculosis (TB) is a serious infectious disease caused by Mycobacterium tuberculosis (MTB) and a significant health concern worldwide. The main threat to the elimination of TB is the development of resistance by MTB to the currently used antibiotics and more extended treatment methods, which is a massive burden on the health care system. As a result, there is an urgent need to identify new, effective therapeutic strategies with fewer adverse effects. The traditional medicines found in South Asia and Africa have a reservoir of medicinal plants and plant-based compounds that are considered another reliable option for human beings to treat various diseases. Abundant research is available for the biotherapeutic potential of naturally occurring compounds in various diseases but has been lagging in the area of TB. Plant-based compounds, or phytoproducts, are being investigated as potential anti-mycobacterial agents by reducing bacterial burden or modulating the immune system, thereby minimizing adverse effects. The efficacy of these phytochemicals has been evaluated through drug delivery using nanoformulations. This review aims to emphasize the value of anti-TB compounds derived from plants and provide a summary of current research on phytochemicals with potential anti-mycobacterial activity against MTB. This article aims to inform readers about the numerous potential herbal treatment options available for combatting TB.

Medicinal Plant Preparations Administered by Botswana Traditional Health Practitioners for Treatment of Worm Infections Show Anthelmintic Activities

Schistosomiasis and soil-transmitted helminths are some of the priority neglected tropical diseases (NTDs) targeted for elimination by the World Health Organization (WHO). They are prevalent in Botswana and although Botswana has begun mass drug administration with the hope of eliminating soil-transmitted helminths as a public health problem, the prevalence of schistosomiasis does not meet the threshold required to warrant large-scale interventions. Although Botswana has a modern healthcare system, many people in Botswana rely on traditional medicine to treat worm infections and schistosomiasis. In this study, ten plant species used by traditional health practitioners against worm infections were collected and tested against Ancylostoma ceylanicum (zoonotic hookworm), Heligmosomoides polygyrus (roundworm of rodents), Necator americanus (New World hookworm), Schistosoma mansoni (blood fluke) [adult and newly transformed schistosomula (NTS)], Strongyloides ratti (threadworm) and Trichuris muris (nematode parasite of mice) in vitro. Extracts of two plants, Laphangium luteoalbum and Commiphora pyaracanthoides, displayed promising anthelmintic activity against NTS and adult S. mansoni, respectively. L. luteoalbum displayed 85.4% activity at 1 μg/mL against NTS, while C. pyracanthoides displayed 78.5% activity against adult S. mansoni at 10 μg/mL.

Antiplasmodial and antimycobacterial activities of crude and lead-like enhanced extracts from Namibian medicinal plants

ETHNOPHARMACOLOGICAL RELEVANCE

Eight indigenous medicinal plants which are used traditionally for the treatment of tuberculosis (TB), malaria, and associated symptoms, were selected for this study.

AIM OF STUDY

The aim of this study was to evaluate the antiplasmodial and antimycobacterial activities of the organic and aqueous crude extracts of different plant parts, by comparing the activities of subfractions (lead-like enhanced [LLE] extracts and methanol fractions) prepared from the bioactive crude extracts.

MATERIALS & METHODS

Crude aqueous and organic extracts were prepared for 25 different plant parts obtained from eight plant species. In vitro antiplasmodial activity was evaluated using the parasite lactate dehydrogenase assay against chloroquine-sensitive Plasmodium falciparum NF54 and in vitro antimycobacterial activity determined against the Mycobacterium tuberculosis H37Rv-GFP strain in a standard broth microdilution assay. The bioactive crude extracts were subjected to solid phase extraction with Strata-X 33 μm reversed phase cartridges and eluted with 70:30 MeOH: H₂O:1% trifluoroacetic acid to yield the LLE extract, followed by a methanol rinse, herein referred to as the MeOH fraction. Both fractions were evaluated for antiplasmodial and antimycobacterial activity. Proton nuclear magnetic resonance spectroscopy (¹H-NMR) and ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) profiling of the crude and active fractions of the phytochemically unexplored Sarcocaulon marlothii Engl. were performed to aid the identification of a potential antiplasmodial lead compound.

RESULTS

Ten of the aqueous and organic crude extracts displayed antimycobacterial activity, with minimum inhibitory concentration (MIC₉₀) values ranging from 9.9 to 86.8 μg/mL, and four crude extracts showed antiplasmodial activity with inhibitory concentration (IC₅₀) values between 5.2 and 17.8 μg/mL. Although the stems of S. marlothii are traditionally used to treat TB and related symptoms, the two crude extracts displayed weak antimycobacterial activity (MIC₉₀ > 100 μg/mL) while the crude organic extract displayed moderate antiplasmodial activity with an IC₅₀ value of 8.8 μg/mL. None of the LLE extracts prepared from the ten antimycobacterial-active crudes displayed any significant activity (MIC₉₀ > 125 μg/mL). In contrast, fractionation of three antiplasmodial-active, crude organic extracts yielded MeOH fractions which displayed a 2-fold to 19-fold increase in activity. The ¹H-NMR profiles of the active MeOH fraction (IC₅₀ 4.3 μg/mL) of S. marlothii (organic, stem) revealed the likely presence of an unidentified trisubstituted cinnamic acid derivative as one of the major compounds and UPLC-MS/MS data provided additional evidence that the compound may be a hydroxycinnamic acid derivative. Unfortunately, owing to the paucity of the material obtained, we were unable to purify and unequivocally determine the structure of this active compound.

CONCLUSIONS

This is the first report on the phytochemical profiling of S. marlothii and, based on the antiplasmodial activity recorded, it merits an in-depth phytochemical analysis for the unequivocal characterization of a potential antiplasmodial lead compound. Results from this study lend support to the effectiveness of extract enrichment in combination with NMR fingerprinting for antiplasmodial lead identification.

Traditionally used polyherbals in a southern African therapeutic context

ETHNOPHARMACOLOGICAL RELEVANCE

In African traditional medicine, there are several plant species that are used in combination with either other plant species or non-plant derived combinations such as sugar and honey, salt and vinegar, milk, fat etc. This review examines the role of these combinations and postulates the scientific and therapeutic validation of such combinations.

AIM OF THE STUDY

This study reviewed the ethnopharmacological literature and documented the use of southern African plant combinations to find a scientific rationale for such combinations, and provide recommendations for future studies.

MATERIALS AND METHODS

Ethnobotanical books and online databases such as Scopus, ScienceDirect, PubMed and Google Scholar were used to find ethnobotanical studies within the southern African context that focus on the combinations of plants with other plants or various additional ingredients. The scientific literature was examined to determine if evidence was available to substantiate such combinations.

RESULTS

One hundred and eighty-seven medicinal plant (plant-to-plant) combinations that are used in the southern African traditional healing system were recorded. These plant combinations were used against infections of the gastrointestinal tract, respiratory tract, and skin as well other non-infectious diseases such as reproductive and psychiatric disorders. Respiratory infections were the most documented infections to be treated using plant combinations. The plant that was documented to be most commonly used in combination with other plants was Artemisia afra Jacq. ex Willd. While plant-plant combinations have drawn a marked interest, comparatively, plant-adjuvant (e.g. milk, sugar, honey, salt, vinegar, fats) combinations have attracted less research interest. Milk was reported as the most used additional ingredient in combination with medicinal plants. The combination of animal urine and dung with medicinal plants has been reported as a treatment for treat prostate infections, the human immunodeficiency virus (HIV). Other ingredients such as clay and flour were also documented, and these are often mixed with medicinal plants to treat fever, stomach ailments, sexually transmitted infections (STI) and skin conditions. Although combination therapy has been frequently reported in ethnobotanical records, over 90% of the combinations reviewed still need to be scientifically validated.

CONCLUSION

Scientific reports on the antimicrobial, anti-oxidant, anti-inflammatory and other pharmacological effects of these combinations may offer an understanding of traditional combination therapy. In addition, investigation into the mechanisms of action of these combinations are also recommended to supplement the findings. Nonetheless, the use of plant combinations is still an untapped research area in southern Africa and there is a need to validate the use of those documented combinations to obtain a better understanding of combined traditional medicinal plant use.

An Annotated Inventory of Tanzanian Medicinal Plants Traditionally Used for the Treatment of Respiratory Bacterial Infections

This review comprehensively covers and analyzes scientific information on plants used in Tanzanian traditional medicine against respiratory diseases. It covers ethnobotanical and ethnopharmacological information extracted from SciFinder, Google Scholar, and Reaxys as well as the literature collected at the Institute of Traditional Medicine in Dar-es-Salaam. Crude extracts and fractions of 133 plant species have literature reports on antimicrobial bioassays. Of these, 16 plant species had a minimum inhibitory activity of MIC ≤ 50 µg/mL. Structurally diverse compounds were reported for 49 plant species, of which 7 had constituents with MIC ≤ 5 µg/mL against various bacteria: Bryophyllum pinnatum (Lam.) Oken, Warburgia ugandensis Sprague, Diospyros mespiliformis Hochst. ex DC., Cassia abbreviata Oliv., Entada abyssinica A. Rich., Strychnos spinosa Lam., and Milicia excelsa (Welw.) C.C. Berg. The low number of antimicrobial active extracts and compounds suggests that antibacterial and antimycobacterial drug discovery needs to have a fresh look at ethnobotanical information, diverting from too reductionist an approach and better taking into account that the descriptions of symptoms and concepts of underlying diseases are different in traditional African and modern Western medicine. Nevertheless, some structurally diverse compounds found in anti-infective plants are highlighted in this review as worthy of detailed study and chemical modification.

Phytochemical screening, antimycobacterial activity and acute toxicity of crude extracts of selected medicinal plant species used locally in the treatment of tuberculosis in Uganda

Background

Tuberculosis (TB) is one of the leading causes of death globally, and the rise in drug-resistant forms of TB has become a significant threat. Subsequently, it is crucial to explore new, effective and safe anti-TB agents. This study aimed at conducting phytochemical screening, antimycobacterial activity, and acute toxicity of the selected plant species’ crude extracts to assess their toxicological potentials and efficacies against TB.

Methods

The aqueous and methanol/dichloromethane (DCM) (1:1) extracts of each selected plant species were subjected to phytochemical screening and antimycobacterial activity using microplate alamar blue assay. For acute toxicity, a single dose (2000 mg/kg) of the aqueous extracts was orally administered to each animal following the Organization for Economic Cooperation and Development (OECD) guidelines No. 425 and then observed for 14 days. The animals were closely observed on the general behavior and clinical signs of toxicity, and body weights were recorded. After the termination of the experiment, hematological, biochemical, and histopathological analyses were performed.

Results

The extracts contained alkaloids, flavonoids, tannins, saponins, steroids, terpenoids, resins, cardiac glycosides, phenolic compounds, and coumarins. Aqueous extracts showed moderate to weak activity against the susceptible (H₃₇Rv) M. tuberculosis strain and weak activity against the MDR-TB strain with Minimum Inhibitory Concentrations (MIC μg/mL) ranging from 293.0–2344.0 and 1172.0–4688.0, respectively. Methanol/DCM extracts showed significant to moderate activity against the susceptible TB strain and moderate to weak activity against the MDR-TB strain with MIC (μg/mL) ranging from 98.0–586.0 and 293.0–781.0, respectively. One mortality was recorded from the A. coriaria treated group following the acute toxicity tests, but the LD₅₀ of all the extracts was estimated to be above 2000 mg/kg. Histopathological analyses did not show any significant lesions in the examined organs except those from the A. coriaria treated group.

Conclusion

Phytochemical screening of the extracts revealed the presence of alkaloids, tannins, saponins, flavonoids, steroids, terpenoids, resins, cardiac glycosides, phenolic compounds, and coumarins. All the methanol/DCM extracts of the plant species studied have promising antimycobacterial activity. The selected plant extracts studied exhibited low acute toxicity levels except for A. coriaria and could be safe for formulations into herbal products.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41182-022-00406-7.

Advances in adjunct therapy against tuberculosis: Deciphering the emerging role of phytochemicals

Eastern countries are a major source of medicinal plants, which set up a rich source of ethnopharmacologically known medicines used in the treatment of various diseases. These traditional medicines have been known as complementary, alternative, or nonconventional therapy across globe for ages. Tuberculosis (TB) poses a huge global burden and leads to maximum number of deaths due to an infectious agent. Treatment of TB using Directly Observed Treatment Short-course (DOTS) therapy comprises multiple antibiotics is quite lengthy and causes serious side-effects in different organs. The length of the TB treatment leads to withdrawal from the patients, which paves the way for the emergence of drug resistance in the bacterial population. These concerns related to therapy need serious and immediate interventions. Traditional medicines using phytochemicals has shown to provide tremendous potential in TB treatment, mainly in the eradication of Mycobacterium tuberculosis (M.tb), increasing natural immunity, and managing the side effects of anti-TB drugs. This review describes the antituberculosis potential of selected ethnopharmacologically important phytochemicals as potential immune-modulator and as an adjunct-therapy in TB. This review will be a useful reference for researchers working on ethnopharmacology and will open the door for the discovery of novel agents as an adjunct-therapy to tuberculosis.

Traditional Medicinal Plants as a Source of Antituberculosis Drugs: A System Review

Medicinal plants are the chief components in the different oriental formulations in different traditional medical systems worldwide. As a thriving source of medicine, the medicinal plants with antituberculosis (TB) properties inspire the pharmacists to develop new drugs based on their active components or semimetabolites. In the present review, the anti-TB medicinal plants were screened from the scientific literatures, based on the botanical classification and the anti-TB activity. The obtained anti-TB medicinal plants were categorized into three different categories, viz., 159 plants critically examined with a total 335 isolated compounds, 131 plants with their crude extracts showing anti-TB activity, and 27 plants in literature with the prescribed formula by the traditional healers. Our systemic analysis on the medicinal plants can assist the discovery of novel and more efficacious anti-TB drugs.

Vhavenda Herbal Remedies as Sources of Antihypertensive Drugs: Ethnobotanical and Ethnopharmacological Studies

Hypertension is a dominant risk factor for the development of cardiovascular, kidney, and eye diseases. In Africa, it increasingly leads to hospitalisation and a strain on the public health system. However, rather than modern medicine, African traditional healers are the first choice for most South Africans. Therefore, this study is aimed at gathering information on herbal remedies traditionally used for the treatment of high blood pressure in Vhavenda, South Africa, and comparing this information with reports in the literature regarding plants used to manage high blood pressure. An ethnobotanical survey was carried out in Vhembe district and its environs with 53 herbalists and indigenous people aged between 36 and 66 years from January to October 2019 using a semistructured questionnaire. The plants were collected with each respondent; they were authenticated and kept in herbarium. A total of 51 different plants were mentioned as being most commonly used for hypertension treatment. Of these, 44 plants were identified, with those from the Fabaceae family followed by plants from the Celastraceae family being commonly mentioned. Of these, the Elaeodendron transvaalense, Tabernaemontana elegans, Elephantorrhiza elephantina, and Aloe vossii were commonly cited species. According to the literature data, most of the identified plants are yet to be scientifically investigated for the treatment of hypertension, whereas only preliminary investigations have been carried out on other plants, suggesting that these preliminary investigations may have highlight promising antihypertensive activities in vitro that are indicative of their potential as antihypertensive drugs. Therefore, there is a need to scientifically investigate the antihypertensive potentials of these plants as a potential source of antihypertensive treatment and compounds.

The traditional use of southern African medicinal plants for the treatment of bacterial respiratory diseases: A review of the ethnobotany and scientific evaluations

ETHNOPHARMACOLOGICAL RELEVANCE

Multiple plant species were used traditionally in southern Africa to treat bacterial respiratory diseases. This review summarises this usage and highlights plant species that are yet to be verified for these activities.

AIM OF THE STUDY

This manuscript reviews the traditional usage of southern African plant species to treat bacterial respiratory diseases with the aim of highlighting gaps in the literature and focusing future studies.

MATERIALS AND METHODS

An extensive review of ethnobotanical books, reviews and primary scientific studies was undertaken to identify southern African plants which are used in traditional southern African medicine to treat bacterial respiratory diseases. We also searched for southern African plants whose inhibitory activity against bacterial respiratory pathogens has been conmfirmed, to highlight gaps in the literature and focus future studies.

RESULTS

One hundred and eighty-seven southern African plant species are recorded as traditional therapies for bacterial respiratory infections. Scientific evaluations of 178 plant species were recorded, although only 42 of these were selected for screening on the basis of their ethnobotanical uses. Therefore, the potential of 146 species used teraditionally to treat bacterial respiratory diseases are yet to be verified.

CONCLUSIONS

The inhibitory properties of southern African medicinal plants against bacterial respiratory pathogens is relatively poorly explored and the antibacterial activity of most plant species remains to be verified.

Medicinal plants used in the treatment of tuberculosis - Ethnobotanical and ethnopharmacological approaches

Tuberculosis is a highly infectious disease declared a global health emergency by the World Health Organization, with approximately one third of the world's population being latently infected with Mycobacterium tuberculosis. Tuberculosis treatment consists in an intensive phase and a continuation phase. Unfortunately, the appearance of multi drug-resistant tuberculosis, mainly due to low adherence to prescribed therapies or inefficient healthcare structures, requires at least 20 months of treatment with second-line, more toxic and less efficient drugs, i.e., capreomycin, kanamycin, amikacin and fluoroquinolones. Therefore, there exists an urgent need for discovery and development of new drugs to reduce the global burden of this disease, including the multi-drug-resistant tuberculosis. To this end, many plant species, as well as marine organisms and fungi have been and continue to be used in various traditional healing systems around the world to treat tuberculosis, thus representing a nearly unlimited source of active ingredients. Besides their antimycobacterial activity, natural products can be useful in adjuvant therapy to improve the efficacy of conventional antimycobacterial therapies, to decrease their adverse effects and to reverse mycobacterial multi-drug resistance due to the genetic plasticity and environmental adaptability of Mycobacterium. However, even if some natural products have still been investigated in preclinical and clinical studies, the validation of their efficacy and safety as antituberculosis agents is far from being reached, and, therefore, according to an evidence-based approach, more high-level randomized clinical trials are urgently needed.

Ethnobotany, ethnopharmacology, and phytochemistry of traditional medicinal plants used in the management of symptoms of tuberculosis in East Africa: a systematic review

OBJECTIVE

Many studies on the treatment of tuberculosis (TB) using herbal medicines have been undertaken in recent decades in East Africa. The details, however, are highly fragmented. The purpose of this study was to provide a comprehensive overview of the reported medicinal plants used to manage TB symptoms, and to analyze scientific reports on their effectiveness and safety.

METHOD

A comprehensive literature search was performed in the major electronic databases regarding medicinal plants used in the management of TB in East Africa. A total of 44 reports were retrieved, and data were collected on various aspects of the medicinal plants such as botanical name, family, local names, part(s) used, method of preparation, efficacy, toxicity, and phytochemistry. The data were summarized into percentages and frequencies which were presented as tables and graphs.

RESULTS

A total of 195 species of plants belonging to 68 families and 144 genera were identified. Most encountered species were from Fabaceae (42.6%), Lamiaceae (19.1%), Asteraceae (16.2%), and Euphorbiaceae (14.7%) families. Only 36 medicinal plants (18.5%) have been screened for antimycobacterial activity. Out of these, 31 (86.1%) were reported to be bioactive with minimum inhibitory concentrations ranging from 47 to 12,500 μg/ml. Most tested plant extracts were found to have acceptable acute toxicity profiles with cytotoxic concentrations on normal mammalian cells greater than 200 μg/ml. The most commonly reported phytochemicals were flavonoids, terpenoids, alkaloids, saponins, cardiac glycosides, and phenols. Only Tetradenia riparia, Warburgia ugandensis, and Zanthoxylum leprieurii have further undergone isolation and characterization of the pure bioactive compounds.

CONCLUSION

East Africa has a rich diversity of medicinal plants that have been reported to be effective in the management of symptoms of TB. More validation studies are required to promote the discovery of antimycobacterial drugs and to provide evidence for standardization of herbal medicine use.

Ziziphus mucronata Willd. (Rhamnaceae): it's botany, toxicity, phytochemistry and pharmacological activities

Ziziphus mucronata is an important multi-purpose plant species that has been used in African traditional medicine for ages in the treatment of various devastating human and animal infections. The current paper is aimed at providing an overview of uses, toxicology, pharmacological properties and phytochemistry of Z. mucronata. The information used in the current work was retrieved using various search engines, including Pubmed, Science Direct, Google Scholar, Scielo, SciFinder and Scopus. The key words used included Ziziphus mucronata, secondary metabolites, chemistry, biological activity and pharmacology, anti-inflammatory, antimicrobial, antifungal, antiviral, ethnobotanical survey, medicinal uses, safety, toxicology and other related words. Out of the 46 infections which the plant species is used to treat, the most common uses includes sexually transmitted infections, skin infections, diarrhoea and dysentery, respiratory and chest complaints and gynaecological complaints (citations ≥6). Pharmacologically, the plant species exhibited a potential antimicrobial activity yielding a minimum inhibitory concentration of <1 mg/ml against important pathogens which includes Mycobacterium tuberculosis, Moraxella catarrhalis, Staphylococcus aureus, Escherichia coli, Propionibacterium acnes, Candida albicans, Cryptoccoos neoformans amongst other microorganisms. Furthermore, the extracts and compounds from Z mucronata revealed potent antiviral, antioxidant, anti-inflammatory and other activities in vitro. Phytochemically, cyclo-peptide alkaloids (commonly called mucronines) dominates and in conjunction with triterpenes, flavonoids, phenolic acids and anthocyanins. Besides these compounds, the plant species exhibited the presence of important in minerals. These phytoconstituents may well explain the reported biological activities. Although the extracts revealed no cytotoxic effect to Vero cells, further toxicological characteristics of the plant species still needs to be explored. There is also a need to carry out the comprehensive safety profiles of the plant species, including heavy metal detection. Although the plant species revealed important biological activities, which includes antimicrobial, antiviral, anti-diabetic, anti-inflammatory, anti-oxidant, anti-plasmodial, anthelmintic, and anti-anaemic activity in vitro, further research is needed to explore the in vivo studies, other compounds responsible for such activities and the mechanisms of action thereof. Such activities validates the use of the plant species in traditional medicine. The data on the possible use of the plant species in the treatment of diarrhoea, sexually transmitted infections, skin related and gynaecological complaints are scant and still needs to be explored and validated both in vitro and in vivo. Furthermore, the anticancer and anthelmintic activity of the plant species also needs to be explored.

Quantitative CE analysis of punicalagin in Combretum aculeatum extracts traditionally used in Senegal for the treatment of tuberculosis

Mycobacterium tuberculosis is the causative agent of tuberculosis, an infectious bacterial disease, which most commonly affects the lungs. In the search for novel active compounds or medicines against tuberculosis, an ethnopharmacological survey combined with a host-pathogen assay has recently highlighted the potency of an aqueous extract of Combretum aculeatum. C. aculeatum is used in traditional medicine and has demonstrated a significant in vitro antimycobacterial activity. Punicalagin, an ellagitannin, was isolated and found to be related to the biological activity of the extract. An analytical method for the evaluation of punicalagin in C. aculeatum was developed by capillary electrophoresis. After method optimization, the quantification of punicalagin was achieved for the evaluation of various plant extracts to determine the content of punicalagin related to the extraction modes and conditions, origin of the plant material, and harvesting period. The developed method demonstrated that the leaves presented the highest punicalagin content compared to the seeds and stems. A decoction of 30 min in boiling water was found to be the best extraction mode of C. aculeatum.

Terminalia laxiflora and Terminalia brownii contain a broad spectrum of antimycobacterial compounds including ellagitannins, ellagic acid derivatives, triterpenes, fatty acids and fatty alcohols

ETHNOPHARMACOLOGICAL RELEVANCE

Terminalia laxiflora Engl. & Diels, (Sudanese Arabic name: Darout الدروت) and Terminalia brownii Fresen (Sudanese Arabic name: Alshaf ألشاف) (Combretaceae) are used in Sudanese traditional folk medicine and in other African countries for treatment of infectious diseases, TB and its symptoms, such as cough, bronchitis and chest pain.

AIM OF STUDY

Because of the frequent use of T. laxiflora and T. brownii in African traditional medicine and due to the absence of studies regarding their antimycobacterial potential there was a need to screen extracts of T. laxiflora and T. brownii for their growth inhibitory potential and to study the chemical composition and compounds in growth inhibitory extracts.

MATERIALS AND METHODS

The plant species were collected in Sudan (Blue Nile Forest, Ed Damazin Forestry areas) and selected according to their uses in traditional medicine for the treatment of bacterial infections, including TB. Eighty extracts and fractions of the stem bark, stem wood, roots, leaves and fruits of T. laxiflora and T. brownii and nine pure compounds present in the active extracts were screened against Mycobacterium smegmatis ATCC 14468 using agar diffusion and microplate dilution methods. Inhibition zones and MIC values were estimated and compared to rifampicin. HPLC-UV/DAD, GC/MS and UHPLC/Q-TOF MS were employed to identify the compounds in the growth inhibitory extracts.

RESULTS

The roots of T. laxiflora and T. brownii gave the best antimycobacterial effects (IZ 22-27 mm) against Mycobacterium smegmatis. The lowest MIC of 625 µg/ml was observed for an acetone extract of the root of T. laxiflora followed by methanol and ethyl acetate extracts, both giving MIC values of 1250 µg/ml. Sephadex LH-20 column chromatography purification of T. brownii roots resulted in low MIC values of 62.5 µg/ml and 125 µg/ml for acetone and ethanol fractions, respectively, compared to 5000 µg/ml for the crude methanol extract. Methyl (S)-flavogallonate is suggested to be the main active compound in the Sephadex LH- 20 acetone fraction, while ellagic acid xyloside and methyl ellagic acid xyloside are suggested to give good antimycobacterial activity in the Sephadex LH-20 ethanol fraction. RP-18 TLC purifications of an ethyl acetate extract of T. laxiflora roots resulted in the enrichment of punicalagin in one of the fractions (Fr5). This fraction gave a five times smaller MIC (500 µg/ml) than the crude ethyl acetate extract (2500 µg/ml) and this improved activity is suggested to be mostly due to punicalagin. 1,18-octadec-9-ene-dioate, stigmast-4-en-3-one, 5α-stigmastan-3,6-dione, triacontanol, sitostenone and β-sitosterol were found in antimycobacterial hexane extracts of the stem bark of both studied species. Of these compounds, 1,18-octadec-9-ene-dioate, stigmast-4-en-3-one, 5α-stigmastan-3,6-dione, triacontanol, sitostenone have not been previously identified in T. brownii and T. laxiflora. Moreover, both plant species contained friedelin, betulinic acid, β-amyrine and two unknown oleanane-type triterpenoids. Of the listed compounds, friedelin, triacontanol and sitostenone gave a MIC of 250 µg/ml against M. smegmatis, whereas stigmasterol and β-sitosterol gave MIC values of 500 µg/ml.

CONCLUSIONS

Our results show that T. laxiflora and T. brownii contain antimycobacterial compounds of diverse polarities and support the traditional uses of various parts of T. laxiflora and T.brownii as decoctions for treatment of tuberculosis. Further investigations are warranted to explore additional (new) antimycobacterial compounds in the active extracts of T. laxiflora and T. brownii.

Scientific rationale for traditional use of plants to treat tuberculosis in the eastern region of the OR Tambo district, South Africa

ETHNOPHARMACOLOGICAL RELEVANCE

Tuberculosis (TB) remains a major health problem for humans worldwide, and was responsible for 1.4 million human deaths in 2015 alone. Although there is treatment for TB, emerging multi-drug, extensively drug and totally drug resistant forms of this disease, as well as co-infection with human immunodefiency virus (HIV) continue to worsen the situation. South Africa is among countries with reported traditional use and published documentation of such knowledge concerning the use of plants against TB. Based on a previous study where plants used traditionally for treating TB in the eastern region of OR Tambo district, South Africa, were documented, the present study aimed to determine the antimycobacterial effect, cytotoxicity and genotoxicity of plants selected from that list.

MATERIAL AND METHODS

Acetone, 70% ethanol, cold and hot water extracts were tested for antimycobacterial activity against saprophytic Mycobacterium species including M. aurum, M. bovis BCG, M. gordonae, M. fortuitum, and M. smegmatis using a microdilution method. Extracts with MIC values less than 1 mg/ml against at least three Mycobacterium strains were evaluated for antimycobacterial activity against pathogenic Mycobacterium strains including M. tuberculosis H37RV, M. tuberculosis and M. bovis, cytotoxicity (against Vero monkey kidney and bovine dermis cells), and genotoxicity (against Salmonella typhimurium TA98 and TA100).

RESULTS

The MIC values of the extracts ranged from 0.02 to 2.50 mg/ml, LC₅₀ values of twenty-nine extracts ranged from 0.001 to > 1 mg/ml and the highest selectivity index was 79.50, an extremely promising value. Phymaspermum acerosum roots and leaves (ethanol and water) extracts had the best MIC value (0.02 mg/ml) against at least one Mycobacterium strain. It was interesting to note the lack of cytotoxicity of these extracts with the highest selectivity index value of 39.75. Pterocelastrus echinatus bark acetone and Protorhus longifolia leaf hot water extracts were the most cytotoxic with LC₅₀ = 0.001 and 0.008 mg/ml, respectively, whereas Pittosporum viridiflorum bark water extract was genotoxic. Among non-pathogenic strains, M. gordonae, M. aurum, M. smegmatis showed good correlation of activity with pathogenic M. tuberculosis H37Rv, M. tuberculosis and M. bovis, however, M. aurum was the best predictor with Mycobacterium tuberculosis H37Rv (correlation coefficient value = 0.73).

CONCLUSION

The results indicate that Heteromorpha trifoliata and Phymaspermum acerosum should be investigated further for antimycobacterial efficacy against drug resistant strains of Mycobacterium.

Ethno-medicinal documentation of polyherbal medicines used for the treatment of tuberculosis in Amathole District Municipality of the Eastern Cape Province, South Africa

CONTEXT

Tuberculosis (TB) has remained a devastating global public health problem. In the continuing search for effective treatment, polyherbal remedies used as alternative medicines in the Eastern Cape Province of South Africa were surveyed.

OBJECTIVE

The survey collected information and documents the list of ingredients such as the name of the plants used including the non-herbal inclusions, type and dosage of polyherbal formulations used for the treatment of TB.

MATERIALS AND METHODS

The survey was conducted over a period of 6 months using semi-structured questionnaires amidst informal conversations with the traditional healers in five communities in the study area. The chosen study area is the third infected Province with TB in South Africa.

RESULTS

A total of nine polyherbal preparations were collected. Information on the parts of the plant used, mode of preparation and the dosage used were documented. In total, the herbs belong to 20 families of which Apiaceae, Liliaceae, Strychnaceae, Rutaceae and Hypoxidaceae are the most prominent. However, members of Apiaceae were commonly mentioned for the preparation of the remedies. The two most frequently used plants were Allium sativum L. (Liliaceae) and Strychnos decussata (Pappe) Gilg. (Strychnaceae). Rhizome was the commonest parts used, followed by the roots and barks.

CONCLUSIONS

This paper provides significant ethno-medicinal information on polyherbal medicines used for the treatment of TB in the study area. The therapeutic claims made on medicinal plants used for the preparations are well supported by the literature, with many of the species having antimicrobial properties.

Ethnopharmacology and Therapeutic Value of Bridelia micrantha (Hochst.) Baill. in Tropical Africa: A Comprehensive Review

Bridelia micrantha is traditionally used in tropical Africa to treat a wide range of human and animal diseases. The aim of this study was to summarise the research that has been done on the ethnomedicinal uses, phytochemistry and pharmacological properties of B. micrantha so as to understand its importance and potential value in primary healthcare systems. The literature search for information on ethnomedicinal uses and pharmacological activities of B. micrantha was undertaken using databases such as Web of Science, Scopus, Google Scholar, Science Direct, BioMed Central (BMC), PubMed and Springerlink. Other relevant literature sources included books, book chapters, websites, theses, conference papers and other scientific publications. This study showed that B. micrantha is used as herbal medicine in just over half (57.3%) of the countries in tropical Africa where it is indigenous. A total of 54 ethnomedicinal uses of B. micrantha have been recorded with a high degree of consensus on burns, wounds, conjunctivitis, painful eyes, constipation, gastric ulcers, cough, headache, rheumatism, painful joints, dysentery, ethnoveterinary medicine, malaria, sexually transmitted infections, stomach ache, tape worms and diarrhoea. Different plant parts, aqueous and organic extracts exhibited anthelmintic, antimicrobial, anticonvulsant and sedative, antidiabetic, antidiarrhoeal, antinociceptive, antioxidant, antiplasmodial, antischistosomal, hepatoprotective, insecticidal and β-lactamase inhibitory activities.

Anti-mycobacterium tuberculosis activity of polyherbal medicines used for the treatment of tuberculosis in Eastern Cape, South Africa

BACKGROUND

The emergence of drug-resistant strains of Mycobacterium tuberculosis has become a global public health problem. Polyherbal medicines offer great hope for developing alternative drugs for the treatment of tuberculosis.

OBJECTIVE

To evaluate the anti-tubercular activity of polyherbal medicines used for the treatment of tuberculosis.

METHODS

The remedies were screened against Mycobacterium tuberculosis H37Rv using Middlebrook 7H9 media and MGIT BACTEC 960 system. They were liquid preparations from King Williams Town site A (KWTa), King Williams Town site B (KWTb), King Williams Town site C (KWTc), Hogsback first site (HBfs), Hogsback second site (HBss), Hogsback third site (HBts), East London (EL), Alice (AL) and Fort Beaufort (FB).

RESULTS

The susceptibility testing revealed that all the remedies contain anti-tubercular activity with KWTa, KWTb, KWTc, HBfs, HBts, AL and FB exhibiting more activity at a concentration below 25 µl/ml. Furthermore, MIC values exhibited inhibitory activity with the most active remedies from KWTa, HBfs and HBts at 1.562 µg/ml. However, isoniazid showed more inhibitory activity against M. tuberculosis at 0.05 µg/ml when compare to the polyherbal remedies.

CONCLUSION

This study has indicated that these remedies could be potential sources of new anti-mycobacterial agents against M. tuberculosis. However, the activity of these preparations and their active principles still require in vivo study in order to assess their future as new anti-tuberculosis agents.

Antimicrobial natural product research: A review from a South African perspective for the years 2009-2016

ETHNOPHARMACOLOGICAL RELEVANCE

This review provides information on the antimicrobial research which has taken place on South African natural products for the last eight years (2009-2016). This important field is the backbone of all studies involving the use of medicinal plants against infectious diseases and hence can form the mainstay for future studies.

MATERIALS AND METHODS

All publications within the years 2009-2016 were considered. Exclusion criteria were studies not involving South African medicinal natural products and those publications where full articles could not be accessed. An overview of the most common experimental methods used and new advances in terms of antimicrobial investigations are provided. Disease categories selected for further investigation were skin and wounds, respiratory, gastrointestinal, sexually transmitted and ophthalmic infections amongst others. Alternate natural products and combinations studies were also included.

RESULTS

The minimum inhibitory concentration (MIC) was the most commonly used experimental method to determine antimicrobial activity. Staphylococcus aureus was the most commonly tested skin pathogen and Klebsiella pneumoniae was the most common pathogen implicated in respiratory disorders. Only 20% of gastrointestinal studies included commonly implicated pathogens such as Shigella flexneri and Campylobacter species.

CONCLUSION

Multidisciplinary studies have emerged as a strong support for antimicrobial investigations and show the importance of including toxicity when studying antimicrobial efficacy. Alternate approaches (for example biofilms and quorum sensing) at examining antimicrobial effects are encouraged. Studies on resistant strains require more insight and future recommendations should look at consistent dosing and investigations on compound interactions amongst others.

RETRACTED: Medicinal plants used in the treatment of tuberculosis - Ethnobotanical and ethnopharmacological approaches

Tuberculosis is a highly infectious disease declared a global health emergency by the World Health Organization, with approximately one third of the world's population being latently infected with Mycobacterium tuberculosis. Tuberculosis treatment consists in an intensive phase and a continuation phase. Unfortunately, the appearance of multi drug-resistant tuberculosis, mainly due to low adherence to prescribed therapies or inefficient healthcare structures, requires at least 20months of treatment with second-line, more toxic and less efficient drugs, i.e., capreomycin, kanamycin, amikacin and fluoroquinolones. Therefore, there exists an urgent need for discovery and development of new drugs to reduce the global burden of this disease, including the multi-drug-resistant tuberculosis. To this end, many plant species, as well as marine organisms and fungi have been and continue to be used in various traditional healing systems around the world to treat tuberculosis, thus representing a nearly unlimited source of active ingredients. Besides their antimycobacterial activity, natural products can be useful in adjuvant therapy to improve the efficacy of conventional antimycobacterial therapies, to decrease their adverse effects and to reverse mycobacterial multi-drug resistance due to the genetic plasticity and environmental adaptability of Mycobacterium. However, even if some natural products have still been investigated in preclinical and clinical studies, the validation of their efficacy and safety as antituberculosis agents is far from being reached, and, therefore, according to an evidence-based approach, more high-level randomized clinical trials are urgently needed.

Ethnobotany, phytochemistry, toxicology and pharmacological properties of Terminalia sericea Burch. ex DC. (Combretaceae) - A review

ETHNOPHARMACOLOGICAL REFERENCE

The use of medicinal plants in the treatment of infections is ancient. A wide variety of ethnotherapeutic properties and pharmacological actions has been attributed to Terminalia sericea. Studies by various groups of investigators reveal that it is a multipurpose medicinal plant used mostly in the treatment of diarrhoea, sexually transmitted infections, skin rashes, tuberculosis and other infections. The current paper is aimed at providing an overview of the ethnomedicinal uses, toxicology, pharmacology and the phytochemistry of Terminalia sericea.

MATERIALS AND METHODS

Information was retrieved using various search engines, including Pubmed, Science Direct, Google Scholar, Scielo, SciFinder and Scopus. The key words used included Terminalia sericea, secondary metabolites, phytochemistry, biological activity, pharmacology, ethnobotanical survey, medicinal uses, safety, toxicology and other related words.

RESULTS

Terminalia sericea is an important medicinal plant which possesses anti-HIV, anti-fungal, anti-bacterial, anticancer, lipolytic, wound healing, antiparasitic, anti-inflammatory and anti-oxidant activity, as the most valuable biological activities, thus lending pharmacological support to the plant's folkloric uses in indigenous medicine. Toxicologically, the extracts and isolated compounds from the plant species may have mild toxic effects. Phytochemically, the plant species possesses valuable compounds including triterpenes, alkaloids and flavonoids which may well contribute to its biological activity.

CONCLUSIONS

Terminalia sericea contains secondary metabolites which are valuable in the treatment of a variety of human infections, including community acquired infections which may be prevalent in developing countries. The degree of toxicity reported in various extracts warrants further exploration of the cytotoxicity of the plant species, both against normal human cell lines and in vivo. Moreover, the acetylcholinesterase inhibitory and anti-inflammatory effects also need to be further investigated as there are only a few reports from the literature on these aspects. There is also a need to further understand the mode of action of the extracts against various enzymes relating to inflammation. Antioxidant activity of the plant extracts against various forms of free radicals needs to be investigated. Although T. sericea is reported to be used for ethnoveterinary infections, there are no scientific reports on the anti-parasitic activity of the plant species against common animal parasites.

In vitro and In vivo antimycobacterial, hepatoprotective and immunomodulatory activity of Euclea natalensis and its mode of action

ETHNOPHARMACOLOGICAL RELEVANCE

The Natal gwarri or Natal ebony (Euclea natalensis A.DC.) is a deciduous tree found widespread throughout southern Africa, especially in Kwazulu-Natal and the southern cost. It has been widely used by indigenous communities such as the Zulus, Tsongas and Vendas for symptoms related to tuberculosis (TB). The decoctions made from the plant parts are administered for chest diseases to treat complications such as chest pains, bronchitis, pleurisy and asthma. TB is prevalent in immune-compromised patients and it is evident that TB-drugs cause hepatotoxicity. The objective of the present study was therefore to evaluate the antimycobacterial activity of the ethanolic extract of E. natalensis against TB and its hepatoprotective and immunomodulatory activities.

MATERIALS AND METHODS

The antimycobacterial, antioxidant, hepatoprotective, immunomodulatory activity and cytotoxicity of the ethanolic extract of the shoots of E. natalensis were determined in vitro. The mechanism of action of the antituberculosis activity was determined by investigating the inhibitory effect on mycothiol disulfide reductase enzyme. Furthermore, the acute, sub-acute toxicity (50-2000mg/kg) and antimycobacterial effect (300mg/kg) of E. natalensis shoot extract were investigated in Balb/c mice. Hepatoprotective activity of the extract (50-150mg/kg) was evaluated on isoniazid and rifampicin (50mg/kg; i.p.) induced hepatic damage in a rat model.

RESULTS

The minimum inhibitory concentration of the extract was found to be 125µg/ml against Mycobacterium tuberculosis. The extracts 50% inhibitory concentration (IC₅₀) against 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical was found to be 22.55µg/ml. The plant showed a hepatoprotective effect (50% at 12.5µg/ml) and the ability to increase T-helper 1 cell cytokines; Interleukin 12, Interleukin 2 and Interferon α by up to 12 fold and the ability to decrease the T-helper 2 cell cytokine Interleukin 10 4 fold when compared to baseline cytokine production. No cellular toxicity was observed in primary peripheral blood mononuclear cells (PBMC's) and two secondary cell lines; U937 monocytes and Chang liver cells (a derivative of the HepG2 cell line). During mechanistic studies, the extract showed a 50% inhibition of mycothiol reductase activity at 38.62µg/ml. During the acute and sub-acute studies, E. natalensis exhibited no toxic effect and the 50% lethal dose (LD₅₀) was established to be above 2000mg/kg. The extract was able to reduce the mycobacterial load (1.5-fold reduction) in infected mice. Isoniazid and rifampicin caused significant hepatic damage in rats, and the extract was able to reduce the toxicity by 15% and 40% at 50 and 150mg/kg respectively.

CONCLUSION

The present study supports the traditional usage of the plant against tuberculosis symptoms. The study showed the ability of E. natalensis shoot extract to inhibit mycobacterial growth, stimulate an appropriate immune response and have a hepatic protective effect. Due to the extract's significant results for hepatoprotective, immunomodulatory effects and antimycobacterial activity, it may prove to be effective to serve as an adjuvant for TB-patients.

The anti-tubercular activity of Melia azedarach L. and Lobelia chinensis Lour. and their potential as effective anti-Mycobacterium tuberculosis candidate agents

Objective

To evaluate the anti-mycobacterial activity of Melia azedarach L. (M. azedarach) and Lobelia chinensis Lour. (L. chinensis) extracts against the growth of Mycobacterium tuberculosis (M. tuberculosis).

Methods

The anti-M. tuberculosis activity of M. azedarach and L. chinensis extracts were evaluated using different indicator methods such as resazurin microtiter assay (REMA) and mycobacteria growth indicator tube (MGIT) 960 system assay. The M. tuberculosis was incubated with various concentrations (50–800 μg/mL) of the extracts for 5 days in the REMA, and for 4 weeks in MGIT 960 system assay.

Results

M. azedarach and L. chinensis extracts showed their anti-M. tuberculosis activity by strongly inhibiting the growth of M. tuberculosis in a concentration-dependent manner in the REMA and the MGIT 960 system assay. Particularly, the methanol extract of M. azedarach and n-hexane extract of L. chinensis consistently exhibited their effects by effectively inhibiting the growth of M. tuberculosis in MGIT 960 system for 4 weeks with a single-treatment, indicating higher anti-M. tuberculosis activity than other extracts, and their minimum inhibitory concentrations were measured as 400 μg/mL and 800 μg/mL, respectively.

Conclusions

These results demonstrate that M. azedarach and L. chinensis extracts not only have unique anti-M. tuberculosis activity, but also induce the selective anti-M. tuberculosis effects by consistently inhibiting or blocking the growth of M. tuberculosis through a new pharmacological action. Therefore, this study suggests the potential of them as effective candidate agents of next-generation for developing a new anti-tuberculosis drug, as well as the advantage for utilizing traditional medicinal plants as one of effective strategies against tuberculosis.

Distribution and conservation status of the Endangered pepperbark tree Warburgia salutaris (Canellaceae) in Swaziland

The Endangered Warburgia salutaris (Bertol. f.) Chiov. (Canellaceae), a sought-after medicinal plant in southern Africa, is on the verge of extinction as a result of overexploitation for illegal trade. As part of formulating a conservation strategy for the species in Swaziland we sought to determine its distribution and population status and to revise its national conservation status. Field surveys were conducted in all physiographic regions of Swaziland. Eighteen locations of species presence were found, of which 14 were new records. Three were within protected areas, and seven were in areas worthy of protection. The largest subpopulations occurred in two of the latter areas, Ngudzeni and Sitsatsaweni (351 and 230 individuals, respectively), and one unprotected area, Bulunga (250 individuals). Warburgia salutaris has a severely fragmented distribution and an area of occupancy of 192 km2. Of 700 mature individuals 38% were ring-barked and 7% felled, and some subpopulations had ring-barked juveniles. This indicates a plausible decline in number of mature individuals. Most localities in unprotected areas are eroded and invaded by alien plants, indicating a decline in habitat quality. Our findings indicate that W. salutaris should be categorized as Endangered nationally based on criteria B2ab (iii,v). Although this status implies a lower level of threat than the previous national categorization as Critically Endangered, it does not imply an improved conservation effort in the country, but rather a more accurate assessment based on more data. We have clarified the conservation status of W. salutaris in Swaziland, discovered some previously undocumented subpopulations and identified potential conservation interventions. We recommend that this information be used in setting priorities to ensure conservation of the species.

Ximenia caffra Sond. (Ximeniaceae) in sub-Saharan Africa: A synthesis and review of its medicinal potential

ETHNOPHARMACOLOGICAL RELEVANCE

Ximenia caffra Sond. (Ximeniaceae), commonly known as "sour plum" is traditionally used, both topically and orally to treat a wide range of human diseases and ailments such as wounds, sexually transmitted infections (STIs), infertility, stomach ache, fever, eye problems, diarrhoea, bilharzia, menorrhagia, malaria, intestinal worms, impotence and coughs. The bark and fruits are used by small-scale farmers as ethnoveterinary medicine to treat dermatophilosis, foot rot, saddle sores and control ectoparasites. Oil from X. caffra seed is traditionally used as a moisturiser, soap and shampoo for dry, fragile and damaged hair.

AIM OF THE REVIEW

The aim of this study was to comprehensively summarize the research that has been done on the botany, ethnomedicinal uses, phytochemistry and biological activities of X. caffra in different locations throughout its geographical range in the sub-Saharan African region so as to understand its importance and potential in primary healthcare systems.

MATERIALS AND METHODS

This study was carried out using a comprehensive and systematic literature search on the ethnomedicinal uses, phytochemistry and biological activities of the species throughout its distributional range. Literature sources included papers published in international journals, reports from international, regional and national organizations, conference papers, books and theses. PubMed and Scopus, search engines such as Google Scholar and online collection ScienceDirect were used.

RESULTS

This study showed that X. caffra is used as traditional medicine in 83.3% of the countries in tropical Africa where it is indigenous. A total of 65 human and animal ailments and diseases are recorded for X. caffra, with a high degree of consensus for wounds, sexually transmitted infections (STIs), infertility, stomach ache, fever, eye problems, diarrhoea, bilharzia, menorrhagia, malaria, intestinal worms and coughs. Phytochemical investigation of X. caffra revealed that the species has various compounds including flavonoids, phenols, phytosterols, tannins and fatty acids. Different plant parts, aqueous and organic extracts exhibited anti-amoebic, antibacterial, antifungal, anti-inflammatory, antioxidant, antiparasitic, antiproliferative, HIV-1 reverse transcriptase (RT) inhibitory, insecticidal, non-mutagenic and toxicity activities.

CONCLUSION

In this review, the ethnomedicinal uses, phytochemistry, biological activities and toxicity of different extracts and compounds of X. caffra have been summarized. Although many of the ethnomedicinal uses of X. caffra have been validated by phytochemical and pharmacological studies, there are still some gaps where current knowledge could be improved. There are very few to nil experimental animal studies, randomized clinical trials and target-organ toxicity studies involving X. caffra and its derivatives that have been carried out so far. At the present moment, there is not sufficient evidence to interpret the specific chemical mechanisms associated with some of the documented biological activities of the species. Therefore, future studies should identify the bioactive components, details of the molecular modes or mechanisms of action, pharmacokinetics and physiological pathways for specific bioactives of X. caffra.

Tuberculosis and nature's pharmacy of putative anti-tuberculosis agents

Due to the growing problem of drug resistant Mycobacterium tuberculosis strains, coupled with the twinning of tuberculosis (TB) to human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), the burden of TB is now difficult to manage. Therefore, new antimycobacterial agents are being sought from natural sources. This review focuses on natural antimycobacterial agents from endophytes and medicinal plants of Africa, Europe, Asia, South America and Canada. In the countries mentioned in this review, numerous plant species display putative anti-TB activity. Several antimycobacterial chemical compounds have also been isolated, including: ellagitannin punicalagin, allicin, anthraquinone glycosides, iridoids, phenylpropanoids, beta-sitosterol, galanthimine, crinine, friedelin, gallic acid, ellagic acids, anthocyanidin, taraxerol, termilignan B, arjunic acid, glucopyranosides, 1-epicatechol, leucopelargonidol, hydroxybenzoic acids, benzophenanthridine alkaloids, neolignans, and decarine. These compounds may provide leads to novel and more efficacious drugs to lessen the global burden of TB and drug-resistant M. tuberculosis strains. If there is a long-term remedy for TB, it must lie in nature's pharmacy of putative antimycobacterial agents.

Warburgia: a comprehensive review of the botany, traditional uses and phytochemistry

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Warburgia (Canellaceae) is represented by several medicinal trees found exclusively on the African continent. Traditionally, extracts and products produced from Warburgia species are regarded as important natural African antibiotics and have been used extensively as part of traditional healing practices for the treatment of fungal, bacterial and protozoal infections in both humans and animals. We here aim to collate and review the fragmented information on the ethnobotany, phytochemistry and biological activities of ethnomedicinally important Warburgia species and present recommendations for future research.

MATERIALS AND METHODS

Peer-reviewed articles using "Warburgia" as search term ("all fields") were retrieved from Scopus, ScienceDirect, SciFinder and Google Scholar with no specific time frame set for the search. In addition, various books were consulted that contained botanical and ethnopharmacological information.

RESULTS

The ethnopharmacology, phytochemistry and biological activity of Warburgia are reviewed. Most of the biological activities are attributed to the drimane sesquiterpenoids, including polygodial, warburganal, muzigadial, mukaadial and ugandensial, flavonoids and miscellaneous compounds present in the various species. In addition to anti-infective properties, Warburgia extracts are also used to treat a wide range of ailments, including stomach aches, fever and headaches, which may also be a manifestation of infections. The need to record anecdotal evidence is emphasised and conservation efforts are highlighted to contribute to the protection and preservation of one of Africa's most coveted botanical resources.

Securidaca longipedunculata Fresen (Polygalaceae): a review of its ethnomedicinal uses, phytochemistry, pharmacological properties and toxicology

ETHNOPHARMACOLOGICAL RELEVANCE

Securidaca longipedunculata Fresen (Polygalaceae) is a multi-purpose plant with a long history of use in African traditional medicine to treat various sexually transmitted infections, hernias, coughs, fever, ascariasis, constipation, headaches, rheumatism, stomach ache, malaria, tuberculosis, pain, epilepsy, pneumonia, skin infections, and it is also used as an aphrodisiac for men. The current paper provides an overview of the present phytochemistry, toxicology, ethnomedicinal uses and pharmacological properties of S. longipedunculata.

MATERIALS AND METHODS

The information reported in this paper was collected from a literature search using various computerised databases including ScienceDirect, Scopus, Scielo, PubMed and Google Scholar. The extra information was sourced from various academic dissertations, theses and botanical books.

RESULTS

Phytochemically, extracts from various parts of S. longipedunculata, especially the root bark, contain numerous valuable compounds including xanthones, some benzyl benzoates and triterpene saponins amongst others. Toxicity studies, both in vivo and in vitro, revealed that extracts are only toxic at relatively high concentrations. Furthermore, extracts have antimicrobial, antioxidant, antiparasitic, anti-diabetic, anti-inflammatory, antimalarial, insecticidal, pesticidal, and anticonvulsant properties.

CONCLUSIONS

S. longipedunculata is an important plant species with potential benefits in the treatment of transmissible and infectious diseases, including malaria, tuberculosis, and those caused by community acquired microorganisms. Although extracts from this species generally have little toxicity at low concentrations, further efforts are required to investigate the potential toxicity of S. longipedunculata. The antimicrobial properties of extracts and purified compounds against microorganisms causing sexually transmitted infections are also deserving of further research. Moreover, the pharmacokinetic properties of extracts and compounds of the species need to be explored as there is insufficient data available on these aspects.

Antimicrobial evaluation of plants used for the treatment of diarrhoea in a rural community in northern Maputaland, KwaZulu-Natal, South Africa

BACKGROUND

Zulu people living in the rural area of Maputaland (KwaZulu-Natal, South Africa) rely heavily on medicinal plants for the treatment of diarrhoea. Abundant availability of medicinal plants in the study area offers low cost health care, but scientific validation is needed in order to lend credibility to the traditional use against many ailments including diarrhoeal infections. With this in mind a study was designed to test the in vitro antimicrobial efficacy of 23 plant species which are used for the treatment of diarrhoea in rural Maputaland. Four 1:1 plant combinations were also evaluated to determine their interactive effects against seven diarrhoea-related bacterial pathogens.

METHODS

Minimum inhibitory concentration (MIC) assays were undertaken on dichloromethane-methanol (CH2Cl2: MeOH) and aqueous crude extracts. The following micro-organisms were selected for this study and were tested based on their association with stomach ailments and diarrhoea; Bacillus cereus (ATCC 11778), Enterococcus faecalis (ATCC 29212), Escherichia coli (ATCC 8739), Proteus vulgaris (ATCC 33420), Salmonella typhimurium (ATCC 14028), Shigella flexneri (ATCC 25875) and Staphylococcus aureus (ATCC 12600). The fractional inhibitory concentration index (ΣFIC) was determined for plants traditionally used in combination.

RESULTS

Shigella flexneri proved to be the most susceptible pathogen, where the organic extract of Terminalia sericea showed the most prominent noteworthy antibacterial activity (mean MIC value of 0.04 mg/mL). The aqueous extracts generally showed poorer antimicrobial activity with some exceptions i.e. Acacia burkei, Brachylaena transvaalensis against B. cereus and B. transvaalensis against S. flexneri. In the combination studies, synergy was predominant with mean (across all pathogens) ΣFIC values of 0.30 for Acanthospermum glabratum with Krauseola mosambicina; ΣFIC values of 0.46 for A. glabratum with Psidium guajava; ΣFIC values of 0.39 for B. transvaalensis with P. guajava and ΣFIC values of 0.88 (additive) for the combination of B. transvaalensis with Sclerocarya birrea.

CONCLUSION

This study provided some insight into the bacterial in vitro efficacies of plants traditionally used to treat diarrhoea by the people of Northern Maputaland. Very little connection was observed between frequency of use and efficacy. Plant combinations demonstrated favourable efficacy with mostly synergistic effects noted, lending some credibility to their use in combination.

Morphological Changes in the Overall Mycobacterium tuberculosis H37Ra Cell Shape and Cytoplasm Homogeneity due to Mutellina purpurea L. Essential Oil and Its Main Constituents

OBJECTIVE

The aim of this study was to evaluate the antimycobacterial activity of the essential oil (EO) of Mutellina purpurea L. and its main constituents against the M. tuberculosis H37Ra strain.

MATERIALS AND METHODS

The M. purpurea EO was obtained by hydrodistillation, while its main constituents were purchased. The minimal inhibitory concentration values were determined by the log2 dilution method. Visualization of the effects of the tested substances on M. tuberculosis was performed using a transmission electron microscope (TEM). Mathematical shape descriptors such as area, circularity, aspect ratio and roundness were calculated to describe morphological changes in bacterial cell shape.

RESULTS

The EO of M.purpurea and all substances tested in this experiment showed a significant antimycobacterial activity. The most active was α-pinene followed by bisabolol and myrcene (8, 16 and 32 µg/ml, respectively). The EO and limonene exhibited the same antimicrobial activity (64 µg/ml). The TEM images and shape descriptors showed significant changes in the overall tuberculosis cell shape and cytoplasm homogeneity (uniformity and consistency)

CONCLUSIONS

In this study, the low molecular weight compounds of mono- and sesquiterpenes penetrated/destabilized the complex mycobacterial cell wall and decreased its viability. There is a need for further experiments to explain the mechanism of action of these small particles.

Isolation and characterization of antimicrobial compounds from Terminalia phanerophlebia Engl. & Diels leaf extracts

ETHNOPHARMACOLOGICAL RELEVANCE

The emergence of drug resistant-tuberculosis and other pathogenic diseases over the past decades, constitutes a serious threat to human health worldwide. According to a 2012 report by the World Health Organization (WHO), South Africa, China, India and Russia are the countries with the highest prevalence of Multi-Drug Resistant tuberculosis (MDR-tuberculosis) as they represented 60% of the total. Several reports have documented antimycobacterial properties of Terminalia species but only a few species from this genus have been explored for their antimycobacterial constituents. The crude extracts of Terminalia phanerophlebia showed good antimicrobial activities in our previous study against two Mycobacterium as well as two other bacterial strains responsible for opportunistic infections related to respiratory ailments. This paper studies the isolation of compounds responsible for such activities and to isolate compounds responsible for antimicrobial activities from the crude extracts of Terminalia phanerophlebia leaves.

MATERIALS AND METHODS

Terminalia phanerophlebia crude extracts obtained from 80% methanol was successively extracted with hexane, dichloromethane (DCM), ethyl acetate (EtOAc) and n-butanol. The fractions obtained and isolated compounds were tested for their antibacterial activities against Mycobacterium aurum, Mycobacterium tuberculosis, Staphylococcus aureus and Klebsiella pneumoniae. Bioguided fractionation of the EtOAc fraction afforded two bioactive compounds. Structure elucidation was carried out using NMR (1D and 2D) spectroscopic methods.

RESULTS

EtOAc fraction exhibited highest antimicrobial activities and its fractionation afforded methyl gallate (methyl-3,4,5-trihydroxybenzoate) (1) and a phenylpropanoid glucoside, 1,6-di-O-coumaroyl glucopyranoside (2) These compounds are reported from Terminalia phanerophlebia for the first time. Both compounds showed good antimicrobial activity against all bacterial strains tested with minimum inhibitory concentration (MIC) values ranging from 63 to 250 µg/mL. Inhibition of Mycobacterium tuberculosis by 1,6-di-O-coumaroyl glucopyranoside (2) at a MIC value of 63 µg/mL was noteworthy, as this bacterial strain is reported to be the leading cause of tuberculosis worldwide.

CONCLUSIONS

Good antimicrobial activities exhibited by the compounds isolated from Terminalia phanerophlebia authenticate the traditional use of this plant in treating tuberculosis and its related symptoms. Compound (2), 1,6-di-O-coumaroyl glucopyranoside could serve as a lead compound for tuberculosis drug discovery.

Some Nigerian anti-tuberculosis ethnomedicines: a preliminary efficacy assessment

ETHNOPHARMACOLOGICAL SIGNIFICANCE

Nigerian herbalists possess indigenous ethnomedicinal recipes for the management of tuberculosis and related ailments. A collaborative preliminary modern scientific evaluation of the efficacy of some Nigerian ethnomedicines used by traditional medicine practitioners (TMPs) in the management of tuberculosis and related ailments has been carried out.

MATERIALS AND METHODS

Ethnomedicinal recipes (ETMs) were collected from TMPs from locations in various ecological zones of Nigeria under a collaborative understanding. The aqueous methanolic extracts of the ETMs were screened against Mycobacterium bovis, BCG and Mycobacterium tuberculosis strain H37Rv using the broth microdilution method.

RESULTS

Extracts of ETMs screened against BCG showed 69% activity against the organism. The activities varied from weak, ≤2500 µg/mL to highly active, 33 µg/mL 64% of the extracts were active against Mycobacterium tuberculosis The activities of the extracts against Mycobacterium tuberculosis varied from weak, ≤2500 µg/mL to highly active, 128 µg/mL. There was 77% agreement in results obtained using BCG or Mycobacterium tuberculosis as test organisms.

CONCLUSION

The results show clear evidence for the efficacy of the majority of indigenous Nigerian herbal recipes in the ethnomedicinal management of tuberculosis and related ailments. BCG may be effectively used, to a great extent, as the organism for screening for potential anti-Mycobacterium tuberculosis agents. A set of prioritization criteria for the selection of plants for initial further studies for the purpose of antituberculosis drug discovery research is proposed.

Phytotherapeutic information on plants used for the treatment of tuberculosis in eastern cape province, South Africa

The current rate of deforestation in Africa constitutes a serious danger to the future of medicinal plants on this continent. Conservation of these medicinal plants in the field and the scientific documentation of our knowledge about them are therefore crucial. An ethnobotanical survey of plants used for the treatment of tuberculosis (TB) was carried out in selected areas of the Eastern Cape, South Africa. These areas were Hala, Ncera, Sheshegu, and Gquamashe, all within the Nkonkobe Municipality. One hundred informants were interviewed. The survey included the identification of scientific and vernacular names of the plants used for treatment of TB as well as the methods of preparation and administration, the part used, dosage, and duration of treatment. The survey revealed 30 plants belonging to 21 families which are commonly used by traditional healers for the treatment of TB and associated diseases. Of these plants Clausena anisata, Haemanthus albiflos, and Artemisia afra were the most cited. The leaves were the most common part used in the medicinal preparations. Our findings are discussed in relation to the importance of the documentation of medicinal plants.

Knowledge on plants used traditionally in the treatment of tuberculosis in Uganda

ETHNOPHARMACOLOGICAL RELEVANCE

Tuberculosis (TB) is one of the leading causes of morbidity and mortality globally. The disease is especially important because of increasing drug resistant strains and co infection with human immune virus (HIV) and acquired immune disease syndrome (AIDS). Because of this there is need to identify new leads that can be developed into new drugs. The objectives of this study were to (1) document plant species commonly used by traditional medicine practitioners (TMPs) to treat TB, methods of preparation and administration of drugs (2) document disease recognition by TMPs and (3) document medicine preservation and packaging practices by TMPs.

MATERIALS AND METHODS

We interviewed 40 TMPs from Mpigi and Butambala districts using a guided questionnaire.

RESULTS

A total of 90 plant species, distributed within 44 families were documented. Priority plants identified include Zanthoxylum leprieurii, Piptadeniastrum africanum, Albizia coriaria and Rubia cordifolia which were most mentioned by TMPs. TMPs had knowledge of how TB is transmitted and they admitted that it is closely associated with HIV. Decoctions of multiple plant species were commonly used. Plant parts frequently used were leaves followed by the stem bark and root bark. The TMPs had insufficient knowledge about packaging and preservation techniques.

CONCLUSION

Plant based therapies for treating TB have been identified in this study and further investigation of these plants is appropriate as these, may be developed into new drugs to curb the resistant strains of TB.

Bapedi traditional healers in the Limpopo Province, South Africa: their socio-cultural profile and traditional healing practice

BACKGROUND

Bapedi traditional healers play a vital role in the primary health care of rural inhabitants in the Limpopo Province, South Africa. However, literature profiling their social and demographic variables, as well as their traditional healing practices is lacking.

METHODS

Convenience sampling were used to identify and select two traditional healers from 17 municipalities (resulting in 34 healers being used in this pilot survey) of the Limpopo Province in South Africa. Information on the social and demographic variables, and traditional healing practices of these healers was gathered from January 2013 to July 2013, using a semi-structured questionnaire, supplemented by field surveys for plant identification and collection used in the preparation of remedies.

RESULTS

Males constituted nearly two-thirds of the participants. Forty eight percent of them became healers through the mentoring of another healer, while 38% acquired their traditional healing knowledge from parents and 14% from grandparents. In contrast to this, 62% of the females obtained theirs from their parents, 30% from fellow traditional healers, and 8% from grandparents. A total of 154 plant species were indicated as used by healers in the treatment of 52 health-related problems. A vast majority (89%) of these practitioners reported that prepared herbal remedies do expire, which is a temperature-dependent process. Determinations of the efficacy of remedies by most healers (67%) were via consultation with ancestors (90%). This study also found that none of the interviewees had any knowledge of provincial or national environmental legislation.

CONCLUSIONS

The current study has shown that Bapedi traditional healers could play a leading role in both the preservation of indigenous knowledge and the primary health care sector. However, of concern is the traditional methods (via consulting ancestors) employed by most of these healers in determining efficacy of remedies, thus indicating a need for a scientific investigations to establish their safety and effectiveness. Equally, there is a need to educate traditional practitioners' regarding the significance of various conservation legislations in their traditional healing. By addressing these, the national and provincial legislators, medical fraternity as well as environmental agencies will be able to better integrate them in primary health care systems and environmental management.

Plants traditionally used individually and in combination to treat sexually transmitted infections in northern Maputaland, South Africa: antimicrobial activity and cytotoxicity

ETHNOPHARMACOLOGICAL RELEVANCE

Although medicinal plants are used extensively to treat sexually transmitted infections (STIs) in rural northern Maputaland, KwaZulu-Natal, the efficacy and safety of these plants have not previously been evaluated.

AIM OF STUDY

A study was designed to investigate the in vitro antimicrobial activity and cytotoxicity profiles of a selection (individual plants and selected combinations) of traditionally used plants in this study area.

MATERIALS AND METHODS

Aqueous and organic (dichloromethane: methanol, 1:1) extracts were prepared. Antimicrobial activity was assessed using the minimum inhibitory concentration (MIC) assay against the STI associated pathogens; Candida albicans ATCC 10231, Ureaplasma urealyticum clinical strain, Oligella ureolytica ATCC 43534, Trichomonas vaginalis clinical strain, Gardnerella vaginalis ATCC 14018 and Neisseria gonorrhoeae ATCC 19424. For the combination study, interactions were assessed using the fractional inhibitory concentration (ΣFIC). The plant species were assessed for safety using the 3-[4,5-dimethyl-2-thiazol-yl]-2,5-diphenyl-2H-tetrazolium bromide (MTT) cellular viability assay on the human embryonic kidney epithelial (Graham, HEK-293) cell line.

RESULTS

For the antimicrobial studies, U. urealyticum was the most sensitive of the six test organisms, with the aqueous extract of Ranunculus multifidus (0.02mg/ml) and the organic extract of Peltophorum africanum (0.04mg/ml) being the most antimicrobially active plant species studied. Sclerocarya birrea was found to have the broadest spectrum of activity (mean MIC of 0.89mg/ml). The only plant species to exhibit some degree of cytotoxicity against the kidney epithelial cell line was Kigelia africana (100µg/ml), with 22% and 16% cell death for the aqueous and organic extracts, respectively. Of the 13 combinations studied, several synergistic combinations were evident, the most prominent being the combination of Albizia adianthifolia and Trichilia dregeana (aqueous extract) with an ΣFIC value of 0.15 against O. ureolytica. Synergistic interactions were observed regardless of the ratio of the aqueous mixtures of the two plants. Syzygium cordatum and S. birrea (aqueous extract) was also a combination of interest, demonstrating synergistic (ΣFIC=0.42) interactions against O. ureolytica. This combination, however, also displayed some cytotoxicity towards the human epithelial cell line.

CONCLUSION

This study demonstrated that anecdotal evidence of plant use does not always correlate with in vitro activity. Furthermore, the toxicological profiling is of utmost importance as if not combined in its correct ratio can lead to potential adverse effects.

In vitro antimicrobial activity of extracts from plants used traditionally in South Africa to treat tuberculosis and related symptoms

Respiratory ailments are major human killers, especially in developing countries. Tuberculosis (TB) is an infectious disease causing a threat to human healthcare. Many South African plants are used in the traditional treatment of TB and related symptoms, but there has not been a sufficient focus on evaluating their antimicrobial properties. The aim of this study was to evaluate the antimicrobial properties of plants used traditionally to treat TB and related symptoms against microorganisms (Klebsiella pneumoniae, Staphylococcus aureus, and Mycobacterium aurum A+) associated with respiratory infections using the microdilution assay. Ten plants were selected based on a survey of available literature of medicinal plants used in South Africa for the treatment of TB and related symptoms. The petroleum ether, dichloromethane, 80% ethanol, and water extracts of the selected plants were evaluated for antibacterial activity. Out of 68 extracts tested from different parts of the 10 plant species, 17 showed good antimicrobial activities against at least one or more of the microbial strains tested, with minimum inhibitory concentration ranging from 0.195 to 12.5 mg/mL. The good antimicrobial properties of Abrus precatorius, Terminalia phanerophlebia, Indigofera arrecta, and Pentanisia prunelloides authenticate their traditional use in the treatment of respiratory diseases. Thus, further pharmacological and phytochemical analysis is required.

Medicinal plants used for the treatment of tuberculosis by Bapedi traditional healers in three districts of the Limpopo Province, South Africa

The present study was aimed at documenting medicinal plants used for the treatment of tuberculosis (TB) by the Bapedi traditional healers in three districts of the Limpopo Province, South Africa. Fifty two traditional healers from 17 municipalities covering Capricorn, Sekhukhune and Waterberg districts were interviewed between January and July 2011. Twenty one medicinal plant species belonging to 20 genera and 18 families were documented. The majority (61.9%) are indigenous and the rest are exotics, found near homes as weeds or cultivated in home gardens as ornamentals or food plants. Hyacinthaceae, Moraceae and Rutaceae families were the most represented families in terms of species numbers (9.5% each). Herbs and trees (38% each) constituted the largest proportion of the growth forms of the medicinal plants used. Tuberculosis remedies were mostly prepared from leaves (34%) followed by roots (21%). The therapeutic claims made on medicinal plants used to treat TB by the Bapedi traditional healers are well supported by literature, with 71.4% of the species having antimicrobial properties or have similar ethno medicinal uses in other countries. This study therefore, illustrates the importance of medicinal plants in the treatment and management of TB in the Limpopo Province, South Africa.

Medicinal utilization of exotic plants by Bapedi traditional healers to treat human ailments in Limpopo province, South Africa

ETHNOPHARMACOLOGICAL RELEVANCE

Most exotic plants are usually labelled as alien invasives and targeted for eradication. However, some of these exotic plants play an important role in the traditional primary healthcare sector of the Bapedi culture in the Limpopo Province of South Africa. The medicinal uses of most of these species have neither been documented nor their biological activity evaluated.

AIM OF THE STUDY

To make an inventory of exotic species employed by Bapedi traditional healers to treat different human ailments in the Limpopo Province, South Africa.

MATERIALS AND METHODS

Semi-structured interviews, observation and guided field walks with 52 traditional healers were employed to obtain ethnobotanical data during first half of 2011 on the use of exotic plant species by Bapedi healers to treat human ailments. Based on ethnobotanical information provided by these healers, specimens were collected, numbered, pressed, and dried for identification.

RESULTS

A total of 35 exotics species belonging to 21 families and 34 genera, mostly from the Fabaceae and Solanaceae (11.4% for each), Apocynaceae and Asteraceae (8.5% for each) were used by Bapedi healers to treat 20 human ailments. Trees (45.7%) and herbs (37.1%) are the primary source of medicinal plants. Species most frequently reported were used for the treatment of hypertension (35%), diabetes mellitus, erectile dysfunction and gonorrhoea (25% for each). The highest consensus from individual accounts of the traditional healers on the use of exotic plant remedies in this study was noted for the three ailments. These were for Catharanthus roseus (gonorrhoea, 60%), Punica granatum (diarrhoea, 38.4%) and Ricinus communis (sores, 21.5%). Of the 35 exotic plant species recorded, 34.2% are regulated by the Conservation of Agricultural Resources Act (1983) (CARA) No. 43 of 1983 either as worst weeds or invaders.

CONCLUSION

The present study demonstrated that exotic plant species play an important part as medicinal remedies employed by Bapedi healers to treat different human diseases in the Limpopo Province. The use of these species as alternative sources of medicinal remedies could alleviate harvesting pressure of wild indigenous plants, thereby enhance biodiversity's region. However, there is a need to formulate an appropriate policy to retain some of the useful medicinal exotics (listed under CARA No. 43 of 1983) within the environment before their medicinal value vanishes as they are eradicated through management strategies adopted by the South African government.

An antimicrobial evaluation of plants used for the treatment of respiratory infections in rural Maputaland, KwaZulu-Natal, South Africa

ETHNOPHARMACOLOGICAL RELEVANCE

Abundant availability of medicinal plants in the study area offers low cost health care, but scientific validation is needed in order to lend credibility to the traditional use against respiratory infections.

AIM OF THE STUDY

This study focussed on determining the antimicrobial efficacies of 30 plant species (independently and in various combinations) used for respiratory related infections in rural Maputaland.

MATERIALS AND METHODS

In vitro minimum inhibitory concentration (MIC) assays were undertaken on dichloromethane-methanol (CH(2)Cl(2): MeOH) and aqueous extracts, as well as the hydro-distilled essential oils (for aromatic plants). Selected plant parts were assessed for antimicrobial activity against a range of respiratory pathogens i.e. Cryptococcus neoformans (ATCC 14116), Klebsiella pneumoniae (ATCC 13883), Moraxella catarrhalis (ATCC 23246), Mycobacterium smegmatis (ATCC 14468) and Staphylococcus aureus (ATCC 6538). The sum of the fractional inhibitory concentrations (∑FIC) was determined for plants traditionally used in combination. Isobolograms represent MIC values for a selection of interactions where two plants were combined in various ratios.

RESULTS

The most antimicrobially active aqueous extracts were that of Ozoroa obovata and Sclerocarya birrea (0.10 mg/ml) while organic extracts from Parinari capensis subsp. incohata and Tetradenia riparia demonstrated the most noteworthy (0.03 mg/ml) activity. Although both Lippia javanica and Eucalyptus grandis were by far the most popular plants traditionally used for respiratory infections, the antimicrobial activity was mostly only moderate. Furthermore, the traditional use in a 1:1 combination did not display strong antimicrobial interactions, but isobolograms demonstrate (against some test organisms) that when combined in various ratios, predominant additive interactions are evident where E. grandis was present in larger proportions. The combination of E. grandis with O. obovata demonstrated synergism against both C. neoformans and K. pneumoniae, with ∑FIC values of 0.34 and 0.28 respectively. Various ratios of these two plants also demonstrated a predominantly synergistic profile.

CONCLUSION

Although this in vitro study supports the traditional use of some plants independently and in combination for the treatment of respiratory ailments in rural Maputaland, results demonstrate that the traditional selection of plants in higher frequency do not necessarily correlate with higher antimicrobial efficacy.

Treatment of diarrhoea in rural African communities: an overview of measures to maximise the medicinal potentials of indigenous plants

Diarrhoea is a major cause of morbidity and mortality in rural communities in Africa, particularly in children under the age of five. This calls for the development of cost effective alternative strategies such as the use of herbal drugs in the treatment of diarrhoea in these communities. Expenses associated with the use of orthodox medicines have generated renewed interest and reliance on indigenous medicinal plants in the treatment and management of diarrhoeal infections in rural communities. The properties of many phenolic constituents of medicinal plants such as their ability to inhibit enteropooling and delay gastrointestinal transit are very useful in the control of diarrhoea, but problems such as scarcity of valuable medicinal plants, lack of standardization of methods of preparation, poor storage conditions and incertitude in some traditional health practitioners are issues that affect the efficacy and the practice of traditional medicine in rural African communities. This review appraises the current strategies used in the treatment of diarrhoea according to the Western orthodox and indigenous African health-care systems and points out major areas that could be targeted by health-promotion efforts as a means to improve management and alleviate suffering associated with diarrhoea in rural areas of the developing world. Community education and research with indigenous knowledge holders on ways to maximise the medicinal potentials in indigenous plants could improve diarrhoea management in African rural communities.

Plants used for treating respiratory infections in rural Maputaland, KwaZulu-Natal, South Africa

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional remedies are frequently used in treating various respiratory ailments, and are very important in the primary health care of the people living in rural Maputaland, KwaZulu-Natal, South Africa. Novel information gathered from surveys like the present study is important in preserving indigenous knowledge.

AIM OF THE STUDY

To explore the knowledge that the lay people of a rural community in northern Maputaland have about medicinal plants used in the vicinity to treat respiratory infections.

MATERIALS AND METHODS

Interviews were conducted among 80 homestead inhabitants, using structured questionnaires where convenience sampling was used. The focus was on plants used in treating respiratory infections. Some of the main topics discussed during the interviews were vernacular plant names, plant parts used, harvested amounts, preparation methods, dosage forms and quantities, use of plants in combination as well as the related symptomatic relief associated with respiratory infections.

RESULTS

The study documented 30 plant species (18 families) which are used to treat respiratory infections by the rural people in the study area. Decoctions made with these plants are mostly taken orally, combined with the use of steaming. To the best of our knowledge, Acanthospermum glabratum, Aloe marlothii, Krauseola mosambicina, Ozoroa obovata, Parinari capensis and Plectranthus neochilus are recorded for the first time globally as medicinal plants used for treating respiratory infections and related symptoms. The indigenous aromatic shrub, Lippia javanica was by far the most frequently used plant species, followed by Eucalyptus grandis (an exotic), Tetradenia riparia and then Senecio serratulloides. Twenty-four different plant combinations were used where the most frequently used combination encountered was Eucalyptus grandis with Lippia javanica.

CONCLUSION

The large number of different plant species traditionally used against respiratory infections supports previous research on the importance of traditional medicine in the primary health care of this remote area. The finding of new vernacular plant names and plant uses in the current survey shows the importance of the documentation of such ethnobotanical knowledge.

Characterization of n-Hexane sub-fraction of Bridelia micrantha (Berth) and its antimycobacterium activity

Background

Tuberculosis, caused by Mycobacterium tuberculosis (MTB), is the most notified disease in the world. Development of resistance to first line drugs by MTB is a public health concern. As a result, there is the search for new and novel sources of antimycobacterial drugs for example from medicinal plants. In this study we determined the in vitro antimycobacterial activity of n-Hexane sub-fraction from Bridelia micrantha (Berth) against MTB H₃₇Ra and a clinical isolate resistant to all five first-line antituberculosis drugs.

Methods

The antimycobacterial activity of the n-Hexane sub-fraction of ethyl acetate fractions from acetone extracts of B. micrantha barks was evaluated using the resazurin microplate assay against two MTB isolates. Bioassay-guided fractionation of the ethyl acetate fraction was performed using 100% n-Hexane and Chloroform/Methanol (99:1) as solvents in order of increasing polarity by column chromatography and Resazurin microtiter plate assay for susceptibility tests.

Results

The n-Hexane fraction showed 20% inhibition of MTB H₃₇Ra and almost 35% inhibition of an MTB isolate resistant to all first-line drugs at 10 μg/mL. GC/MS analysis of the fraction resulted in the identification of twenty-four constituents representing 60.5% of the fraction. Some of the 24 compounds detected included Benzene, 1.3-bis (3-phenoxyphenoxy (13.51%), 2-pinen-4-one (10.03%), N(b)-benzyl-14-(carboxymethyl) (6.35%) and the least detected compound was linalool (0.2%).

Conclusions

The results show that the n-Hexane fraction of B. micrantha has antimycobacterial activity.