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

An inventory and analysis of the medicinal plants of Mozambique

ETHNOPHARMACOLOGICAL RELEVANCE

A comprehensive checklist and analysis of medicinal plant species and their uses in Mozambique, and a comparison with South Africa provided a more profound understanding of the broad concept of Traditional African Medicine as a healing culture and the need for a more informative classification system.

AIMS OF THE STUDY

This study was aimed at recording all medicinal plants reported in Mozambique according to literature and answer four main questions. 1. How many medicinal plant species have been recorded for Mozambique? Of those, how many are indigenous to Mozambique, and how many are introduced or cultivated exotics? 2. What are the main medicinal uses in Mozambique and which species are used for which ailments? 3. What are the similarities and differences between the medicinal floras of Mozambique and South Africa - are the same species used for the same ailments and is there evidence of cultural exchange? 4. Do the data provide new insights into Traditional African Medicine as one of the oldest medicine systems in the world?

MATERIALS AND METHODS

A literature survey was done to compile the medicinal checklist of Mozambique using 29 available literature sources, which were found from published books, journal articles, reports, unpublished theses, dissertations, and online databases.

RESULTS

A total of 731 medicinal plant species and infraspecific taxa from 447 genera and 120 families was recorded for Mozambique. Of these, 590 (81%) are indigenous, and 87 are non-indigenous (50 naturalised and 37 cultivated exotics). Of the 731 medicinal plant species, 494 (68%) are also used medicinally in South Africa and 148 (30%) are used for the same or similar ailments. Many of the shared taxa and uses have been recorded in the adjoining KwaZulu-Natal Province of South Africa, which has similar vegetation types.

CONCLUSION

The similarity between Mozambique and South Africa (and especially the KwaZulu-Natal Province) not only suggest an exchange of traditional knowledge but also indicates the existence of a hitherto unnamed medicinal system of the southern and eastern African Bantu-speaking cultures that is in need of detailed comparative studies.

An Inventory of South African Medicinal Plants Used in the Management of Sexually Transmitted and Related Opportunistic Infections: An Appraisal and Some Scientific Evidence (1990-2020)

The current work is aimed at generating the first inventory of South African medicinal plants used in the treatment of sexually transmitted and related opportunistic infections associated with HIV-AIDS. This is important in assisting researchers to access a list of plant species to evaluate for potential phytocompounds, as this area of research is greatly lagging in South Africa. A total of 335 medicinal plants from 103 families have been documented in the current work. The most represented families are Fabaceae (11.64%) and Asteraceae (6.27%). Herbs constitute 36.53%, trees 32.34%, shrubs 29.04%, climbers 1.80% and parasites 0.30%. It is worrying that on the plant parts used, the roots constitute 47.18%, while leaves and stem bark yield 16.62 and 15.01%, respectively. Catharanthus roseus exhibited the highest number of citations (19), while Peltophorum africanum had 14 and both Carica papaya and Vachelia karoo had 12. In the mode of administration of the reported medicinal plant species, most of the plants are boiled and taken orally (48.22%), while other plant species are used as mouth washes (3.25%). Although there is reasonable in vitro activity of some of the plant species, validating the relevance of use, there is still a need to explore the mode of action of such plant species; isolated compounds and possible derivatives thereof are of paramount importance and need to be explored as well. Furthermore, toxicological aspects of such plant species need to be explored.

The Medicinal Natural Products of Cannabis sativa Linn.: A Review

Cannabis sativa is known among many cultures for its medicinal potential. Its complexity contributes to the historical application of various parts of the plant in ethno-medicines and pharmacotherapy. C. sativa has been used for the treatment of rheumatism, epilepsy, asthma, skin burns, pain, the management of sexually transmitted diseases, difficulties during child labor, postpartum hemorrhage, and gastrointestinal activity. However, the use of C. sativa is still limited, and it is illegal in most countries. Thus, this review aims to highlight the biological potential of the plant parts, as well as the techniques for the extraction, isolation, and characterization of C. sativa compounds. The plant produces a unique class of terpenophenolic compounds, called cannabinoids, as well as non-cannabinoid compounds. The exhaustive profiling of bioactive compounds and the chemical characterization and analysis of C. sativa compounds, which modern research has not yet fully achieved, is needed for the consistency, standardization, and the justified application of Cannabis sativa products for therapeutic purposes. Studies on the clinical relevance and applications of cannabinoids and non-cannabinoid phenols in the prevention and treatment of life-threatening diseases is indeed significant. Furthermore, psychoactive cannabinoids, when chemically standardized and administered under medical supervision, can be the legal answer to the use of C. sativa.

A Review of Recent Studies on the Antioxidant and Anti-Infectious Properties of Senna Plants

The use of phytochemicals is gaining interest for the treatment of metabolic syndromes over the synthetic formulation of drugs. Senna is evolving as one of the important plants which have been vastly studied for its beneficial effects. Various parts of Senna species including the root, stem, leaves, and flower are found rich in numerous phytochemicals. In vitro, in vivo, and clinical experiments established that extracts from Senna plants have diverse beneficial effects by acting as a strong antioxidant and antimicrobial agent. In this review, Senna genus is comprehensively discussed in terms of its botanical characteristics, traditional use, geographic presence, and phytochemical profile. The bioactive compound richness contributes to the biological activity of Senna plant extracts. The review emphasizes on the in vivo and in vitro antioxidant and anti-infectious properties of the Senna plant. Preclinical studies confirmed the beneficial effects of the Senna plant extracts and its bioactive components in regard to the health-promoting activities. The safety, side effects, and therapeutic limitations of the Senna plant are also discussed in this review. Additional research is necessary to utilize the phenolic compounds towards its use as an alternative to pharmacological treatments and even as an ingredient in functional foods.

Invasive alien plants and weeds in South Africa: A review of their applications in traditional medicine and potential pharmaceutical properties

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional pharmacopoeias are constantly evolving and adapting, hence the assimilation of alien plants and weeds into traditional systems of healing. Invasive plants are detrimental to the ecosystem, however they are also potential sources of secondary metabolites with useful biological activities.

AIM OF THE REVIEW

The aim of this review was to investigate published reports of traditional use and biological activity of declared invasive alien plants and other weeds in South Africa.

MATERIALS AND METHODS

Information was retrieved from scientific databases including Scopus, Web of Science, ScienceDirect, Google Scholar, PubMed, Chemical Abstracts Services and books, theses, dissertations and technical reports. Keywords used for the search engines were "South Africa" or "southern Africa" in conjunction with "(native weeds OR alien invasive)" AND "medicinal". Separate searches were conducted on the individual invasive plant species recorded as having been used in ethnobotanical surveys to determine their known biological activities and chemical components.

RESULTS

A total of 89 plant species regarded as invasive species or weeds in South Africa were identified as being used in traditional medicine. The most commonly mentioned plant family was the Asteraceae with a total of 15 species followed by the Fabaceae and Solanaceae with 6 species each. Of the 89 species recorded, 68% were reported to have traditional usage with both phytochemical and biological data available. A history of traditional usage coupled with biological data was available for 12% of species. Records of traditional usage alone were linked to 11% of species. Invasive alien species comprised 61% of recorded species, while native and non-invasive alien weeds formed the remaining 39%.

CONCLUSIONS

The exploration of alternative uses for weeds and particularly invasive plants, whether native or alien, as medicines for possible commercialisation may lead to innovative mechanisms for putting such species to good use.

Yield, Characterization, and Possible Exploitation of Cannabis Sativa L. Roots Grown under Aeroponics Cultivation

Cannabis sativa L. has been used for a long time to obtain food, fiber, and as a medicinal and psychoactive plant. Today, the nutraceutical potential of C.sativa is being increasingly reappraised; however, C. sativa roots remain poorly studied, despite citations in the scientific literature. In this direction, we identified and quantified the presence of valuable bioactives (namely, β-sitosterol, stigmasterol, campesterol, friedelin, and epi-friedelanol) in the root extracts of C. sativa, a finding which might pave the way to the exploitation of the therapeutic potential of all parts of the C. sativa plant. To facilitate root harvesting and processing, aeroponic (AP) and aeroponic-elicited cultures (AEP) were established and compared to soil-cultivated plants (SP). Interestingly, considerably increased plant growth-particularly of the roots-and a significant increase (up to 20-fold in the case of β-sitosterol) in the total content of the aforementioned roots' bioactive molecules were observed in AP and AEP. In conclusion, aeroponics, an easy, standardized, contaminant-free cultivation technique, facilitates the harvesting/processing of roots along with a greater production of their secondary bioactive metabolites, which could be utilized in the formulation of health-promoting and health-care products.

Ficus plants: State of the art from a phytochemical, pharmacological, and toxicological perspective

Ficus genus is typically tropical plants and is among the earliest fruit trees cultivated by humans. Ficus carica L. is the common fig, Ficus benjamina L. is the weeping fig, and Ficus pumila L. is the creeping fig. These species are commonly used in traditional medicine for a wide range of diseases and contain rich secondary metabolites that have shown diverse applications. This comprehensive review describes for Ficus genus the phytochemical compounds, traditional uses and contemporary pharmacological activities such as antioxidant, cytotoxic, antimicrobial, anti-inflammatory, antidiabetic, antiulcer, and anticonvulsant. An extended survey of the current literature (Science Direct, Scopus, PubMed) has been carried out as part of the current work. The trends in the phytochemistry, pharmacological mechanisms and activities of Ficus genus are overviewed in this manuscript: antimicrobial, antidiabetic, anti-inflammatory and analgesic activity, antiseizure and anti-Parkinson's diseases, cytotoxic and antioxidant. Health-promoting effects, recent human clinical studies, safety and adverse effects of Ficus plants also are covered. The medical potential and long-term pharmacotherapeutic use of the genus Ficus along with no serious reported adverse events, suggests that it can be considered as being safe.

Assessment of Useful Alien Plant Species Cultivated and Managed in Rural Home Gardens of Limpopo Province, South Africa

Several communities in developing countries derive substantial part of their livelihood needs from alien plants cultivated and managed in home gardens. The aim of this study was to assess useful alien plant species cultivated and managed in home gardens of Limpopo province in South Africa. Semistructured interviews, personal observation, and guided walks with 300 participants between January 2015 and December 2016 were employed to obtain data on names of alien plants cultivated in home gardens and their use categories. A total of 101 plant species belonging to 44 families were recorded from the study area. More than half of the species (66.3%) belonged to 14 families, Fabaceae, Asteraceae, Rosaceae, Solanaceae, Lamiaceae, Anacardiaceae, Poaceae, Amaranthaceae, Apocynaceae, Brassicaceae, Cactaceae, Euphorbiaceae, Moraceae, and Myrtaceae. Twenty-six use categories of alien plants were identified in this study with the majority of species (75.2%) used for medicinal purposes, followed by ornamental (33.7%), edible fruits (24.8%), spices (16.8%), vegetables (16.8%), shade (11.9%), beverages (10.9%), construction materials (8.9%), firewood (7.9%), and hedge (7.9%). These findings corroborate the existing body of knowledge emphasizing the importance of plants grown and managed in home gardens to the livelihood needs of local communities.

Review: Southern African medicinal plants used as blood purifiers

ETHNOPHARMALOGICAL RELEVANCE

Blood purification practices, also referred to as blood cleansing or detoxification, is an ancient concept which is widespread amongst African traditional medicine, but for which no modern scientific basis exists. There prevails considerable ambiguity in defining what a blood purifier is.

AIM OF THE STUDY

The purpose of this review is to firstly define what a blood purifier is in the context of African traditional medicine and compare to other cultural and westernized interpretations. Thereafter, this study identifies traditionally used medicinal plants used as blood purifiers in southern Africa and correlates these species to scientific studies, which may support evidence for these "blood purifying plant species".

MATERIALS AND METHODS

Ethnobotanical books and review articles were used to identify medicinal plants used for blood purification. Databases such as Scopus, ScienceDirect, PubMed and Google Scholar were used to source scientific articles. An evaluation was made to try correlate traditional use to scientific value of the plant species.

RESULTS

One hundred and fifty nine plant species have been documented as traditional remedies for blood purification. Most of the plant species have some pharmacological activity, however, very little link to the traditional use for blood purification. There has been some justification of the link between blood purification and the use as an antimicrobial and this has been explored in many of the plant species identified as blood purifiers. Other pharmacological studies specifically pertaining to the blood require further attention.

CONCLUSION

Irrespective of the ambiguity of interpretation, medicinal plants used to "cleanse the blood", play an important holistic role in traditional medicine and this review with recommendations for further study provides some value of exploring this theme in the future.

Antipyretic potential of dichloromethane leaf extract of Eucalyptus globulus (Labill) and Senna didymobotrya (Fresenius) in rats models

Introduction

Fever is managed using synthetic drugs such as aspirin, paracetamol among others. Synthetic drugs are associated with many side effects. Herbal medicines form alternative therapy since they possess fewer side effects and are readily available. This study aimed to determine antipyretic potential of DCM extracts of E. globulus and S. didymobotrya in Swiss albino rats.

Materials and methods

The plant leaves samples were obtained from Embu County, Kenya. Dichloromethane solvent was used to extract bioactive constituents from the plant samples. Three grams of DCM leaf extracts of Eucalyptus globulus (Labill) and Senna didymobotrya (Fresenius) samples were obtained and analyzed to determine quantitative phytochemical composition at ICIPE laboratory using GC-MS. Albino rats were used in the antipyretic activity study. Nine groups of five experimental animals were used in each test: Positive control, normal control, negative control and experimental (25, 50, 100, 150, 200 and 250 mg/kg body weight extracts) groups. Pyrexia was induced by injection of turpentine in albino rats intraperitoneally. One hour later, the pyretic animals received the leaf extracts at various dose levels, reference drug (aspirin100 mg/kg body) or the vehicle (DMSO).

Results

Results of antipyretic in vivo bioscreening revealed that E. globulus and S. didymobotrya possess potent antipyretic activity which was comparable to that of the reference drug aspirin. Both extracts exhibited highest antipyretic activity at a dose of 250 mg/kg bw. Results of the GC-MS revealed that these plants possess bio-compounds such as Terpinolene, Alpha-pinene, Borneol, Globulol and Terpineols that are associated with antipyretic activity.

Conclusions

In conclusion, this study revealed that these plants are endowed with bioactive compounds such as terpenoids, and flavonoids that possess antipyretic activity in rats.

Exotic Plants Used by the Hmong in Thailand

Exotic species are an integral part of the plants used by many ethnic groups, but they usually receive little attention and have been considered alien to the ethnobotanical data. Here, we analyze the plants used by Thai Hmong refugees that are not native to their current habitats in Thailand. We attempt to understand the sources of this knowledge. Do people maintain the original traditional knowledge related to exotic species when they migrate to a new region, or does new knowledge originate from acculturation? We interviewed 16 specialist Hmong informants in Nan province, Thailand, about their traditional knowledge of 69 exotic species used. Acquisition of this knowledge has a long history; several species are the same as plants used by the Hmong in China and other countries, others are globally useful species which have become part of the pool of species that the Hmong have developed local knowledge about. However, migration also involves the integration of local knowledge from other cultures, and also adapts them to function in urban settings. This includes using closely related exotic taxa that replace some of the species they used in their original homelands. The migrants' traditional knowledge in their new habitats is more complicated and also involves the development of local knowledge that is entirely new.

Anil Kumar N, Sharopov F, Ramírez-Alarcón K, Ruiz-Ortega A, Abdulmajid Ayatollahi S, Valere Tsouh Fokou P, Kobarfard F, Amiruddin Zakaria Z, Iriti M, Taheri Y, Martorell M, Sureda A, N. Setzer W, Durazzo A, Lucarini M, Santini A, Capasso R, Adrian Ostrander E, -ur-Rahman A, Iqbal Choudhary M, C. Cho W, Sharifi-Rad J. Antidiabetic Potential of Medicinal Plants and Their Active Components

Diabetes mellitus is one of the major health problems in the world, the incidence and associated mortality are increasing. Inadequate regulation of the blood sugar imposes serious consequences for health. Conventional antidiabetic drugs are effective, however, also with unavoidable side effects. On the other hand, medicinal plants may act as an alternative source of antidiabetic agents. Examples of medicinal plants with antidiabetic potential are described, with focuses on preclinical and clinical studies. The beneficial potential of each plant matrix is given by the combined and concerted action of their profile of biologically active compounds.

Alien Plants in the Eastern Cape Province in South Africa: Perceptions of Their Contributions to Livelihoods of Local Communities

Invasive alien plant species are plant species that establish themselves outside their native distributional range. The current study documented utilization of alien plant species in the Eastern Cape province in South Africa. Information about utilization of alien plant species was gathered through interviews conducted with 120 participants, which included 13 traditional healers, 27 herbalists, ten farmers and 70 laypeople. Ethnobotanical importance of documented species was assessed through evaluation of use value (UV), fidelity level (FL) and relative frequency citation (RFC). A third of the participants (33.3%) perceived alien plant species as undesirable, while 71.1% of the participants argued that alien plant species had beneficial effects. A total of 26 alien plant species were recorded, seven species being fruit trees, followed by ornamental plants (five species), fodder and herbal medicines (four species each), construction materials, erosion control and vegetables (two species each). The popular alien plant species with UV > 0.1, RFC > 0.4 and FL > 4.0% included Amaranthus spinosus, Cannabis sativa, Cereus jamaracu, Harrisia balansae, Opuntia engelmannii, Opuntia ficus-indica, Opuntia monocantha and Prunus persica. Information on perceptions of local communities in the Eastern Cape province on the contributions of alien plant species to livelihood needs is an important stage of initiating a management protocol that incorporates public perceptions and values associated with alien plant species.

Anti-mycobacterial activity of some medicinal plants used traditionally by tribes from Madhya Pradesh, India for treating tuberculosis related symptoms

ETHNOPHARMACOLOGICAL RELEVANCE

Tuberculosis (TB) is one of the highly infectious disease caused by the bacterium Mycobacterium tuberculosis (Mtb). Several medicinal plants are traditionally used by the tribal healers of some tribal pockets of Madhya Pradesh (M.P.), India in the treatment of various ailments including TB related symptoms. The information of traditional knowledge of plants is empirical lacking systematic scientific investigation.

AIM OF THE STUDY

To provide a scientific rationale for the traditional uses of some medicinal plants in treating prolonged cough, chest complaints and TB by ethnic groups in four districts of the state of M.P., India. The anti-mycobacterial activity of these plants was also investigated against multidrug-resistant (MDR) strains of Mtb. The active plant extracts were also assessed for general cytotoxicity by human monocytic leukemia cell line, THP-1 macrophages.

MATERIALS AND METHODS

Semi structured interviews and guided field-walk methods were used to gather information on medicinal plants used by the tribal traditional healers. The study was carried out in the tribal pockets of Anuppur, Mandla, Umariya and Dindori districts of M.P., India. A total of 35 plant species distributed in 22 families were selected based on folklore uses suggested by the tribal traditional healer. The ethanol extracts of plants were evaluated for anti-mycobacterial activity against Mtb H37Rv and six MDR clinical isolates of Mtb. The anti-mycobacterial activity of plants was determined in terms of minimum inhibitory concentration (MIC) using standard resazurin microtitre plate assay (REMA). The plant extracts found to be active against Mtb were further evaluated for general cytotoxicity against human THP-1 macrophages using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay. The selectivity index (SI) of active plant extracts were also calculated on the basis of MIC and cytotoxicity.

RESULTS

Out of the 35 plants, 11 plant species showed anti-mycobacterial activity with MIC ranging from 500 to 31.25 µg/mL against Mtb H37Rv. The plant extracts also exhibited anti-mycobacterial activity against six multi-drug resistant (MDR) clinical strains of Mtb isolated from sputum samples of pulmonary TB patients. In vitro cytotoxicity of active plant extracts was also assessed in human THP-1 macrophages. The IC₅₀ (50% inhibitory concentration) values of most of the plant extracts on THP-1 was found to be higher than MIC values against Mtb, indicating that the THP-1 cells are not adversely affected at concentrations that are effective against Mtb. Significant anti-mycobacterial activity was observed for eleven plants viz., Alstonia scholaris (L.) R. Br., Glycyrrhiza glabra L., Holorrhena antidysentrica (Roth) Wall. exA.DC., Mallotus philippensis (Lam.) Müll. Arg., Eulophia nuda Lindl., Cocculus hirsutus (L.) Diels, Pueraria tuberosa (Willd.) DC., Cyperus rotundus L., Curcuma caesia Roxb., Sphaeranthus indicus L. and Plumbago zeylanica L. which lends support to their traditional uses.

CONCLUSION

The present investigation supports the potential role of plants used by tribal healers as our results have shown that these plants exhibit anti-mycobacterial activity in the acceptable range against Mtb. Our study clearly lends support to the traditional uses of some plants in TB related symptoms as we have found them to exhibit significant in vitro anti-TB activity. To the best of our knowledge, anti-mycobacterial activity in plants against Mtb is being reported for the first time from tribal areas of M.P., India by the current study.

Antihyperglycemic and Antihyperlipidemic Effects of Aqueous Extracts of Lannea edulis in Alloxan-Induced Diabetic Rats

Lannea edulis (Sond.) Engl. commonly known as wild grape is used traditionally for the treatment of diabetes. It is only found in Eastern and Southern Africa. Phytochemical screening, antihyperglycemic and antihyperlipidemic effects of aqueous extracts of L. edulis in alloxan induced diabetic rats were carried out. We report herein the findings of this research work. Lannea edulis crude aqueous extracts were obtained by hot infusion and evaporation method. Phytochemical screening was carried out and subsequently toxicity studies of the aqueous extracts were performed to establish the Lethal Dose 50 (LD50) in albino rats. Alloxan monohydrate was used to induce diabetes in the rats. Lannea edulis positive control group doses of 100, 300, and 500 mg/kg were administered to 3 groups for 14 days. The positive control group was administered 5 mg/kg of glibenclamide. The negative and normal control groups were administered distilled water. To determine fasting blood glucose, blood was drawn on days 0, 1, 3, 5, 7, and 14 while it was drawn on days 0 and 14 for the determination of lipids. Phytochemical screening revealed the presence of flavonoids, saponins, tannins, cardiac glycosides, alkaloids and steroids. L. edulis diabetic positive control groups showed significant (P < 0.05) dose dependent reductions in fasting blood glucose levels. When day 0 mean blood glucose levels were compared to day 3 mean blood glucose levels of their respective groups, the 300 mg/kg L. edulis group showed a 23.3% drop and the 500 mg/kg L. edulis group showed a 52.6% drop. The 100 mg/kg L. edulis diabetic positive control group showed a 25.1% drop by day 5, the day on which it showed statistical significance (P < 0.05) compared to the diabetic control. In addition, administration of aqueous extracts of L. edulis to diabetic rats for 14 days significantly decreased (P < 0.05) the levels of serum total cholesterol, triglycerides, Low Density Lipoprotein (LDL) and Very Low Density Lipoprotein (VLDL) whilst increasing the levels of High Density Lipoprotein (HDL), when compared to the diabetic control group. It was concluded that L. edulis showed significant and dose dependent antihyperglycemic and antihyperlipidemic effects thus confirming its traditional use.

Sensing Technologies for Detection of Acetone in Human Breath for Diabetes Diagnosis and Monitoring

The review describes the technologies used in the field of breath analysis to diagnose and monitor diabetes mellitus. Currently the diagnosis and monitoring of blood glucose and ketone bodies that are used in clinical studies involve the use of blood tests. This method entails pricking fingers for a drop of blood and placing a drop on a sensitive area of a strip which is pre-inserted into an electronic reading instrument. Furthermore, it is painful, invasive and expensive, and can be unsafe if proper handling is not undertaken. Human breath analysis offers a non-invasive and rapid method for detecting various volatile organic compounds thatare indicators for different diseases. In patients with diabetes mellitus, the body produces excess amounts of ketones such as acetoacetate, beta-hydroxybutyrate and acetone. Acetone is exhaled during respiration. The production of acetone is a result of the body metabolising fats instead of glucose to produce energy. There are various techniques that are used to analyse exhaled breath including Gas Chromatography Mass Spectrometry (GC-MS), Proton Transfer Reaction Mass Spectrometry (PTR-MS), Selected Ion Flow Tube-Mass Spectrometry (SIFT-MS), laser photoacoustic spectrometry and so on. All these techniques are not portable, therefore this review places emphasis on how nanotechnology, through semiconductor sensing nanomaterials, has the potential to help individuals living with diabetes mellitus monitor their disease with cheap and portable devices.

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.

Cannabis Pharmacology: The Usual Suspects and a Few Promising Leads

The golden age of cannabis pharmacology began in the 1960s as Raphael Mechoulam and his colleagues in Israel isolated and synthesized cannabidiol, tetrahydrocannabinol, and other phytocannabinoids. Initially, THC garnered most research interest with sporadic attention to cannabidiol, which has only rekindled in the last 15 years through a demonstration of its remarkably versatile pharmacology and synergy with THC. Gradually a cognizance of the potential of other phytocannabinoids has developed. Contemporaneous assessment of cannabis pharmacology must be even far more inclusive. Medical and recreational consumers alike have long believed in unique attributes of certain cannabis chemovars despite their similarity in cannabinoid profiles. This has focused additional research on the pharmacological contributions of mono- and sesquiterpenoids to the effects of cannabis flower preparations. Investigation reveals these aromatic compounds to contribute modulatory and therapeutic roles in the cannabis entourage far beyond expectations considering their modest concentrations in the plant. Synergistic relationships of the terpenoids to cannabinoids will be highlighted and include many complementary roles to boost therapeutic efficacy in treatment of pain, psychiatric disorders, cancer, and numerous other areas. Additional parts of the cannabis plant provide a wide and distinct variety of other compounds of pharmacological interest, including the triterpenoid friedelin from the roots, canniprene from the fan leaves, cannabisin from seed coats, and cannflavin A from seed sprouts. This chapter will explore the unique attributes of these agents and demonstrate how cannabis may yet fulfil its potential as Mechoulam's professed "pharmacological treasure trove."

Saponins of Agave: Chemistry and bioactivity

The genus Agave comprises more than 400 species with geographical presence in the tropical and sub-tropical regions of the world. These plants have a rich history of folkloric use and are known for a wide spectrum of applications. Secondary metabolites of diverse chemical classes have been reported from Agave species. Owing to their pharmacological significance, the steroidal saponins of Agave have caught the attention of phytochemists, biologists and drug discovery scientists. The present review describes 141 steroidal saponins and sapogenins and covers the literature published from 1970 to 2015. It is a comprehensive and coherent presentation of the structures, methods of chemical profiling, structure elucidation and biological activities of the saponins and sapogenins reported from Agave. The article provides a perspective of the research on steroidal compounds of Agave.

Cytotoxicity of 91 Kenyan indigenous medicinal plants towards human CCRF-CEM leukemia cells

ETHNOPHARMACOLOGICAL RELEVANCE

Plants from Kenyan flora are traditionally used against many ailments, including cancer and related diseases. Cancer is characterized as a condition with complex signs and symptoms. Recently there are recommendations that ethnopharmacological usages such as immune and skin disorders, inflammatory, infectious, parasitic and viral diseases should be taken into account when selecting plants that treat cancer.

AIM

The present study was aimed at investigating the cytotoxicity of a plethora of 145 plant parts from 91 medicinal plants, most of which are used in the management of cancer and related diseases by different communities in Kenya, against CCRF-CEM leukemia cell line.

MATERIALS AND METHODS

Extracts from different plant parts (leaves, stems, stem bark, roots, root barks, aerial parts and whole herb) were obtained by cold percolation using different solvent systems, such as (1:1v/v) dichloromethane (CH2Cl2) and n-hexane (1), methanol (MeOH) and CH2Cl2 (2); neat MeOH (3), 5% H2O in MeOH (4) and with ethanol (EtOH, 5); their cytotoxicities were determined using the resazurin reduction assay against CCRF-CEM cells.

RESULTS

At a single concentration of 10μg/mL, 12 out of 145 extracts exhibited more than 50% cell inhibition. These include samples from the root bark of Erythrina sacleuxii (extracted with 50% n-hexane-CH2Cl2), the leaves of Albizia gummifera, and Strychnos usambarensis, the stem bark of Zanthoxylum gilletii, Bridelia micrantha, Croton sylvaticus, and Albizia schimperiana; the root bark of Erythrina burttii and E. sacleuxii (extracted with 50% CH2Cl2-MeOH), the stem bark of B. micrantha and Z. gilletii (extracted using 5% MeOH-H2O) and from the berries of Solanum aculeastrum (extracted with neat EtOH). The EtOH extract of the berries of S. aculeastrum and A. schimperiana stem bark extract displayed the highest cytotoxicity towards leukemia CCRF-CEM cells, with IC50 values of 1.36 and 2.97µg/mL, respectively. Other extracts having good activities included the extracts of the stem barks of Z. gilletii and B. micrantha and leaves of S. usambarensis with IC50 values of 9.04, 9.43 and 11.09µg/mL, respectively.

CONCLUSIONS

The results of this study provided information related to the possible use of some Kenyam medicinal plants, and mostly S. aculeastrum, A. schimperiana, C. sylvaticus, Z. gilletii, B. micrantha and S. usambarensis in the treatment of leukemia. The reported data helped to authenticate the claimed traditional use of these plants. However, most plants are used in combination as traditional herbal concoctions. Hence, the cytotoxicity of corresponding plant combinations should be tested in vitro to authenticate the traditional medical practitioners actual practices.

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.

An ethnopharmacological assessment of the use of plants against parasitic diseases in humans and animals

ETHNOPHARMACOLOGICAL RELEVANCE

Ethnobotanical surveys are detecting an increasing frequency of exotic plant species in pharmacopeias, which has led researchers to investigate the role of such species in traditional medical systems. According to the diversification hypothesis, exotic species are included to complete pharmacopeias, i.e., to treat diseases for which no native species are known, thus broadening the scope of the plant repertoire.

MATERIALS AND METHODS

The present study was conducted at two rural communities in northeastern Brazil aiming at a survey of the plants known or used by the population to treat endo- and ectoparasitic diseases in humans and animals. In addition, plant extracts exhibiting acaricide activity were assessed using the engorged female immersion and larval packet tests (LPT).

RESULTS

The results of the present study showed a tendency for native species to be used against ectoparasites and exhibit a broader scope of use compared to exotic species. In turn, exotic species were predominantly indicated to treat diseases caused by endoparasites, although there was an overlap of native and exotic species relative to some therapeutic purpose, e.g., ticks. Only two of the plant species tested exhibited acaricide activity (Nicotiana glauca Graham and Croton blanchetianus Baill.), and in both cases, the activity was weak.

CONCLUSION

The ethnobotanical data do not fully support the suggested hypothesis. Overall, the wide versatility of exotic species was not exclusively used to treat parasitic diseases in humans and animals. In addition, the selection of acaricide plants based on the ethnopharmacological study generated uninteresting results.

Comparative analysis of plant use in peri-urban domestic gardens of the Limpopo Province, South Africa

BACKGROUND

Relatively little has been researched or published on the importance of peri-urban domestic gardens as part of a household livelihood strategy in South Africa. Due to lack of comprehensive data on peri-urban domestic gardens, their potential value as luxury green space, provision of food, income and ecosystem services to the fast growing urban population in South Africa is not clearly known. The aim of this study was to document differences and similarities in plant use and diversity in domestic gardens of two peri-urban communities in the Limpopo Province that differ in proximity to an urban area.

METHODS

Data on plant use categories of 62 domestic gardens in the peri-urban areas of the Limpopo Province were collected in Seshego and Lebowakgomo. Semi-structured interviews, observation and guided field walks with 62 participants were employed between May and October 2012.

RESULTS

A total of 126 plant species were recorded for both Seshego and Lebowakgomo. Domestic gardens in the more remote areas of Lebowakgomo were characterized by higher percentage of food plants (47 species, 83.8% of the total food plants recorded) and medicinal plants (31 species, 83.7%). Lebowakgomo domestic gardens were also characterized by higher numbers of indigenous plants (76.7%) showing similarities to the natural surrounding vegetation in terms of plant species. On the contrary, domestic gardens of Seshego on the periphery of the city centre were characterized by higher percentage of exotic species (81.8%) and ornamental plants (73%), with food plants playing a supplementary role. Comparison of the two areas demonstrated a remarkable difference in plant use and composition.

CONCLUSIONS

This study revealed that there are differences in utilization of plant resources between households on the edge of an urban centre and those in the more remote areas. Food and medicinal plants play an important role in remote areas; while ornamental plants play an important role in urban domestic gardens. But the collective desire for food, medicinal and ornamental plants by both communities on the edge of an urban centre and those in the more remote areas highlight the importance of plant resources in domestic gardens.

Mixed Methods in CAM Research: A Systematic Review of Studies Published in 2012

Background. Mixed methods research uses qualitative and quantitative methods together in a single study or a series of related studies. Objectives. To review the prevalence and quality of mixed methods studies in complementary medicine. Methods. All studies published in the top 10 integrative and complementary medicine journals in 2012 were screened. The quality of mixed methods studies was appraised using a published tool designed for mixed methods studies. Results. 4% of papers (95 out of 2349) reported mixed methods studies, 80 of which met criteria for applying the quality appraisal tool. The most popular formal mixed methods design was triangulation (used by 74% of studies), followed by embedded (14%), sequential explanatory (8%), and finally sequential exploratory (5%). Quantitative components were generally of higher quality than qualitative components; when quantitative components involved RCTs they were of particularly high quality. Common methodological limitations were identified. Most strikingly, none of the 80 mixed methods studies addressed the philosophical tensions inherent in mixing qualitative and quantitative methods. Conclusions and Implications. The quality of mixed methods research in CAM can be enhanced by addressing philosophical tensions and improving reporting of (a) analytic methods and reflexivity (in qualitative components) and (b) sampling and recruitment-related procedures (in all components).

Use of weeds as traditional vegetables in Shurugwi District, Zimbabwe

BACKGROUND

Most agricultural weeds are usually regarded as undesirable and targeted for eradication. However, weeds are useful to human beings as food and traditional medicines. Few studies have been done to document the uses of weeds as traditional vegetables. This study was therefore, done to document indigenous knowledge related to the diversity and use of agricultural weeds as traditional vegetables in Shurugwi District, Zimbabwe, emphasizing their role in food security and livelihoods of the local people.

MATERIALS AND METHODS

Semi-structured interviews, observation and guided field walks with 147 participants were employed between December 2011 and January 2012 to obtain ethnobotanical data on the use of edible weeds as traditional vegetables. Based on ethnobotanical information provided by the participants, botanical specimens were collected, numbered, pressed and dried for identification.

RESULTS

A total of 21 edible weeds belonging to 11 families and 15 genera, mostly from Amaranthaceae (19%), Asteraceae and Tiliaceae (14.3%), Capparaceae, Cucurbitaceae and Solanaceae (9.5% each) were identified. Of the documented edible weeds, 52.4% are indigenous while 47.6% are exotic to Zimbabwe; either semi-cultivated or growing naturally as agricultural weeds in farmlands, fallow land and home gardens. Among the main uses of edible weeds were leafy vegetables (81%), followed by edible fruits (19%), edible corms (9.5%), edible flowers and seeds (4.8% each). The most important edible weeds were Cleome gynandra, cited by 93.9% of the participants, Cucumis metuliferus (90.5%), Cucumis anguria (87.8%), Corchorus tridens (50.3%) and Amaranthus hybridus (39.5%). All edible weeds were available during rainy and harvest period with Cleome gynandra, Corchorus tridens, Cucumis anguria, Cucumis metuliferus and Moringa oleifera also available during the dry season, enabling households to obtain food outputs in different times of the year. The importance of edible weeds for local livelihoods was ubiquitously perceived, with all participants reporting their contribution towards food security and nutrition.

CONCLUSION

The present study confirm findings from similar studies conducted elsewhere that rural households engage in harvesting of wild edible vegetables and other non-timber forest products (NTFPs) as a survival strategy. Based on their potential nutritional and medicinal value, edible weeds could contribute in a major way to food security, basic primary health care and balanced diets of rural households and possibly urban households as well.

Medicinal plants used for the treatment of various skin disorders by a rural community in northern Maputaland, South Africa

BACKGROUND

Skin diseases have been of major concern recently due to their association with the Human Immunodeficiency Virus and Acquired Immunity Deficiency Syndrome (HIV/AIDS). The study area (northern Maputaland) has the highest HIV infection rate in South Africa, which made them more prone to a wide range of skin conditions. Fungal infections due to the hot climate and overcrowding households are common in this area, as well as burn accidents due to the use of wood as the major fuel for cooking. It is known that the lay people in this area depend on medicinal plants for their primary health care. However no survey has been done in northern Maputaland to document the medicinal plants used to treat various skin disorder.

METHODS

Interviews were undertaken at 80 homesteads, using structured questionnaires. The focus was on plants used for dermatological conditions and information regarding vernacular plant names, plant parts used, preparation (independently and in various combinations) and application was collected.

RESULTS

A total of 87 lay people, both male (22%) and female (78%) were interviewed on their knowledge of medicinal plants used to treat disorders of the skin. Forty-seven plant species from 35 families were recorded in the present survey for the treatment of 11 different skin disorders including abscesses, acne, burns, boils, incisions, ringworm, rashes, shingles, sores, wounds and warts. When searching the most frequently used scientific databases (ScienceDirect, Scopus and Pubmed), nine plant species (Acacia burkei, Brachylaena discolor, Ozoroa engleri, Parinari capensis, subsp. capensis, Portulacaria afra, Sida pseudocordifolia, Solanum rigescens, Strychnos madagascariensis and Drimia delagoensis) were found to be recorded for the first time globally as a treatment for skin disorders. Fourteen plant combinations were used. Surprisingly, the application of enema's was frequently mentioned.

CONCLUSIONS

The preference of traditional medicine over allopathic medicine by most of the interviewees strengthens previous studies on the importance that traditional medicine can have in the primary health care system in this rural community. Studies to validate the potential of these plants independently and in their various combinations is underway to provide insight into the anti-infective role of each plant.