Antiplasmodial activity of selected Sudanese medicinal plants with emphasis on Maytenus senegalensis (Lam.) Exell

The effect of an anti-malarial herbal remedy, Maytenus senegalensis, on electrocardiograms of healthy Tanzanian volunteers

BACKGROUND

The emergence of resistance to artemisinin-based combination therapy necessitates the search for new, more potent antiplasmodial compounds, including herbal remedies. The whole extract of Maytenus senegalensis has been scientifically investigated for potential biological activities both in vitro and in vivo, demonstrating strong antimalarial activity. However, there is a lack of data on the electrocardiographic effects of M. senegalensis in humans, which is a crucial aspect in the investigation of malaria treatment. Assessing the electrocardiographic effects of M. senegalensis is essential, as many anti-malarial drugs can inadvertently prolong the QT interval on electrocardiograms. Therefore, the study's objective was to evaluate the electrocardiographic effects of M. senegalensis in healthy adult volunteers.

METHODS

This study is a secondary analysis of an open-label single-arm dose escalation. Twelve healthy eligible Tanzanian males, aged 18 to 45, were enrolled in four study dose groups. A single 12-lead electrocardiogram (ECG) was performed at baseline and on days 3, 7, 14, 28, and 56.

RESULTS

No QTcF adverse events occurred with any drug dose. Only one volunteer who received the highest dose (800 mg) of M. senegalensis experienced a moderate transient change (△QTcF > 30 ms; specifically, the value was 37 ms) from baseline on day 28. There was no difference in maximum QTcF and maximum △QTcF between volunteers in all four study dose groups.

CONCLUSIONS

A four-day regimen of 800 mg every 8 h of M. senegalensis did not impact the electrocardiographic parameters in healthy volunteers. This study suggests that M. senegalensis could be a valuable addition to malaria treatment, providing a safer alternative and potentially aiding in the battle against artemisinin-resistant malaria. The results of this study support both the traditional use and the modern therapeutic potential of M. senegalensis. They also set the stage for future research involving larger and more diverse populations to explore the safety profile of M. senegalensis in different demographic groups. This is especially important considering the potential use of M. senegalensis as a therapeutic agent and its widespread utilization as traditional medicine. Trial registration ClinicalTrials.gov, NCT04944966. Registered 30 June 2021-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04944966?term=kamaka&draw=2&rank=1.

Antiplasmodial and Antileishmanial Activities of a New Limonoid and Other Constituents from the Stem Bark of Khaya senegalensis

Plasmodium falciparum and Leishmania sp. resistance to antiparasitic drugs has become a major concern in malaria and leishmaniasis control. These diseases are public health problems with significant socioeconomic impacts, and mostly affect disadvantaged populations living in remote tropical areas. This challenge emphasizes the need to search for new chemical scaffolds that preferably possess novel modes of action to contribute to antimalarial and antileishmanial research programs. This study aimed to investigate the antimalarial and antileishmanial properties of a methanol extract (KS-MeOH) of the stem bark of the Cameroonian medicinal plant Khaya senegalensis and its isolated compounds. The purification of KS-MeOH led to the isolation of a new ordered limonoid derivative, 21β-hydroxybourjotinolone A (1a), together with 15 known compounds (1bc-14) using a repeated column chromatography. Compound 1a was obtained in an epimeric mixture of 21α-melianodiol (1b) and 21β-melianodiol (1c). Structural characterization of the isolated compounds was achieved with HRMS, and 1D- and 2D-NMR analyses. The extracts and compounds were screened using pre-established in vitro methods against synchronized ring stage cultures of the multidrug-resistant Dd2 and chloroquine-sensitive/sulfadoxine-resistant 3D7 strains of Plasmodium falciparum and the promastigote form of Leishmania donovani (1S(MHOM/SD/62/1S). In addition, the samples were tested for cytotoxicity against RAW 264.7 macrophages. Positive controls consisted of artemisinin and chloroquine for P. falciparum, amphotericin B for L. donovani, and podophyllotoxin for cytotoxicity against RAW 264.7 cells. The extract and fractions exhibited moderate to potent antileishmanial activity with 50% inhibitory concentrations (IC50) ranging from 5.99 ± 0.77 to 2.68 ± 0.42 μg/mL, while compounds displayed IC50 values ranging from 81.73 ± 0.12 to 6.43 ± 0.06 μg/mL. They were weakly active against the chloroquine-sensitive/sulfadoxine-resistant Pf3D7 strain but highly potent toward the multidrug-resistant PfDd2 (extracts, IC50 2.50 ± 0.12 to 4.78 ± 0.36 μg/mL; compounds IC50 2.93 ± 0.02 to 50.97 ± 0.37 μg/mL) with selectivity indices greater than 10 (SIDd2 > 10) for the extract and fractions and most of the derived compounds. Of note, the limonoid mixture [21β-hydroxylbourjotinolone A (1a) + 21α-melianodiol (1b) + 21β-melianodiol (1c)] exhibited moderate activity against P. falciparum and L. donovani. This novel antiplasmodial and antileishmanial chemical scaffold qualifies as a promising starting point for further medicinal chemistry-driven development of a dually active agent against two major infectious diseases affecting humans in Africa.

Antimalarial Efficacy and Safety of Senna occidentalis (L.) Link Root Extract in Plasmodium berghei-Infected BALB/c Mice

Background

Emergence of Plasmodium resistance to antimalarial drugs presents a major drawback in efforts to control malaria. To address this problem, there is an urgent and continuous need for the development of new and effective antimalarial agents. Senna occidentalis (L.) link extract has exhibited in vitro antiplasmodial activity in many pharmacological studies. To our knowledge, data on its in vivo antimalarial efficacy is still very limited. A recent study demonstrated that polar extracts from the plant roots inhibit Plasmodium berghei proliferation in a mouse model. This study further describes the efficacy and safety of a methanolic root extract of the plant as an antimalarial agent by demonstrating its effect on hematological, biochemical, and histological parameters of Plasmodium berghei-infected BALB/c mice.

Methods

Rane's test, a curative approach, was used to evaluate the antimalarial efficacy of Senna occidentalis methanolic root extract in Plasmodium berghei-infected BALB/c mice. The effect of the extract on both hematological and biochemical parameters was evaluated using automated analyzers. Kidney, liver, lung, spleen, and brain tissues were harvested from euthanized mice and examined for changes in organ architecture.

Results

This study demonstrates that methanolic root extract of Senna occidentalis significantly inhibited Plasmodium berghei parasitemia in BALB/c mice (p < 0.01). Infected mice that were treated with the extract depicted a significantly low level of total leucocytes (p < 0.01), red blood cell distribution width (p < 0.01), and a significantly high hemoglobin concentration (p < 0.001) compared to the infected animals that were administered with the vehicle only. The infected animals that were treated with the extract exhibited a significantly low level of urea, creatinine, bilirubin, and alkaline phosphatase (p < 0.05), compared to the infected animals that were given the vehicle only. The level of sodium, potassium and chloride ions, lymphocytes, granulocytes, hematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration, total protein, albumin, aspartate aminotransferase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), total platelets, mean platelet volume (MPV), and platelet distribution width of the infected animals treated with the extract was not significantly different from those of the infected animals that were given the vehicle only (p > 0.05). The extract alleviated organ pathological changes in the infected mice. The extract did not induce any remarkable adverse effect on the growth, hematological, and biochemical parameters of uninfected animals (p > 0.05). In addition, administration of the extract did not alter the gross appearance and histological architecture of the organs, implying that the extract was well tolerated in mice.

Conclusions

Senna occidentalis methanolic root extract exhibited good antimalarial activity against Plasmodium berghei and may be safe in mice.

In Vitro Effect on Plasmodium falciparum and In Vivo Effect on Plasmodium berghei of Annomaal, an Oily Fraction Obtained from the Seeds of Annona squamosa

Malaria remains a life-threatening health problem and is responsible for the high rates of mortality and morbidity in the tropical and subtropical regions of the world. The increasing threat of drug resistance to available artemisinin-based therapy warrants an urgent need to develop new antimalarial drugs that are safer, more effective, and have a novel mode of action. Natural plants are an excellent source of inspiration in searching for a new antimalarial agent. This research reports a systematic investigation for determining the antimalarial potential of the seeds of A. squamosa. The study shows that the crude seed extract (CSE), protein, saponin, and the oily fractions of the seeds were nontoxic at a 2000 mg/kg body weight dose when tested in Wistar rats, thus revealing high safety is classified as class 5. The oily fraction, Annomaal, demonstrated pronounced antimalarial activity with low IC₅₀ (1.25 ± 0.183 μg/mL) against P. falciparum in vitro. The CSE and Annomaal significantly inhibited the growth of P. berghei parasites in vivo with 58.47% and 61.11% chemo suppression, respectively, while the standard drug artemether showed chemo suppression of 66.75%. Furthermore, the study demonstrated that oral administration of Annomaal at a daily dose of 250 mg/kg/day for 3 days was adequate to provide a complete cure to the P. berghei-infected mice. Annomaal thus holds promise as being patient-compliant due to the shorter treatment schedule, eliminating the need for frequent dosing for extended time periods as required by several synthetic antimalarial drugs. Further studies are needed to determine the active compounds in the oily fraction responsible for antimalarial activity.

Senna occidentalis (L.) Link root extract inhibits Plasmodium growth in vitro and in mice

BACKGROUND

Senna occidentalis (L.) Link has been used worldwide in traditional treatment of many diseases and conditions including snakebite. In Kenya, a decoction from the plant roots taken orally, is used as a cure for malaria. Several studies have demonstrated that extracts from the plant possess antiplasmodial activity, in vitro. However, the safety and curative potency of the plant root against established malaria infection is yet to be scientifically validated, in vivo. On the other hand, there are reports on variation in bioactivity of extracts obtained from this plant species, depending on the plant part used and place of origin among other factors. In this study, we demonstrated the antiplasmodial activity of Senna occidentalis roots extract in vitro, and in mice.

METHODS

Methanol, ethyl acetate, chloroform, hexane and water extracts of S. occidentalis root were tested for in vitro antiplasmodial activity against Plasmodium falciparum, strain 3D7. Cytotoxicity of the most active solvent extracts was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and the curative potency in Plasmodium berghei infected mice evaluated by Rane's test.

RESULTS

All of the solvent extracts tested in this study inhibited the propagation of P. falciparum, strain 3D7, in vitro, with polar extracts being more active than non-polar ones. Methanolic extracts had the highest activity (IC50 = 1.76) while hexane extract displayed the lowest activity (IC50 = 18.47). At the tested concentrations, methanolic and aqueous extracts exhibited high selectivity index against P. falciparum strain 3D7 (SI > 10) in the cytotoxicity assay. Further, the extracts significantly suppressed the propagation of P. berghei parasites (P < 0.05) in vivo and increased the survival time of the infected mice (P < 0.0001).

CONCLUSIONS

Senna occidentalis (L.) Link root extract inhibits the propagation of malaria parasites in vitro and in BALB/c mice.

Antiplasmodial and antimalarial evaluation of a Nigerian hepta-herbal Agbo-iba decoction: Identification of magic bullets and possible facilitators of drug action

ETHNOPHARMACOLOGICAL RELEVANCE

Malaria remains one of the most important pathogenic infectious diseases. Although Africa suffers the greatest brunt, a sizeable proportion of her population still relies on herbal medicines for reasons of cost as well as the belief etched in the minds of consumers that herbal medicines are safer and more efficacious than Modern medicines. Agbo-iba; a concoction of two or more than two plants is commonly used for the management of malaria in Nigeria.

AIM OF THE STUDY

This study assessed the safety and efficacy of a hepta-herbal Agbo-iba (HHA) antimalarial decoction used for the management of malaria in Benin city, Nigeria.

MATERIALS AND METHODS

Assessment was done against malaria parasite in culture as well as in vivo in pre-clinical murine model of malaria.

RESULTS

HHA (IC₅₀Pf3D7 50 μg/ml) was moderately potent and only one of its constituent plants Annickia affinis (IC₅₀Pf3D7 1.49 μg/ml) was far more potent, while all others were moderately active to inactive against the parasite in vitro. HHA showed good selectivity in vitro and was safe at 2 g/kg in mice. However, at 100 mg/kg oral dose, while HHA suppressed parasite growth by 56.76%, the suppression caused by A.affinis was only 32.46% in mice malaria suggesting the existence of synergistic partner(s) in the herbal formula. LCMS revealed the presence of quaternary protoberberine alkaloids (QPAs) in A.affinis and HHA.

CONCLUSIONS

Although QPAs have strong in vitro antiplasmodial activity, their in vivo antimalarial activity is undermined by being substrates of Permeability glycoprotein (Pgp) efflux pump. Our study suggests that inhibitor(s) of Pgp in HHA could improve the bioavailability of QPAs in mice fed the herbal combo. Further, molecules from other HHA constituent plants may also contribute to the better potency observed for the polyherbal in vivo. These possibilities were validated by the curative antimalarial study at 100 mg/kg, where A.affinis was inactive but the HHA suppressed parasite growth by 44.45%.

Safety and Tolerability of an Antimalarial Herbal Remedy in Healthy Volunteers: An Open-Label, Single-Arm, Dose-Escalation Study on Maytenus senegalensis in Tanzania

BACKGROUND

Though Maytenus senegalensis is one of the medicinal plants widely used in traditional medicine to treat infectious and inflammatory diseases in Africa, there is a lack of safety data regarding its use. Therefore, the study aimed to asselss the safety and tolerability of the antimalarial herbal remedy M. senegalensis.

MATERIAL AND METHODS

The study design was an open-label, single-arm, dose-escalation. Twelve eligible male healthy Tanzanians aged 18 to 45 years were enrolled in four study dose groups. Volunteers' safety and tolerability post-investigational-product administration were monitored on days 0 to 7,14, and 56.

RESULTS

There were no deaths or serious adverse events in any of the study groups, nor any adverse events that resulted in premature discontinuation. The significant mean changes observed in WBC (p = 0.003), Neutrophils (p = 0.02), Lymphocytes (p = 0.001), Eosinophils (p = 0.009), Alanine aminotransferase (p = 0.002), Creatinine (p = 0.03) and Total bilirubin (p = 0.004) laboratory parameters were not associated with any signs of toxicity or clinical symptoms.

CONCLUSIONS

M. senegalensis was demonstrated to be safe and tolerable when administered at a dose of 800 mg every eight hours a day for four days. This study design may be adapted to evaluate other herbal remedies.

Pharmacological assessment of the heartwood of Acacia raddiana Willd for antifungal potential

As COVID-19 suppresses the immune system and those who have recovered from COVID-19 are at risk of developing mucormycosis or black fungus so there is a need to develop new antifungal strategies by the use of medicinal plants. Medicinal plants have always been a subject of interest for drug discovery, ethno-botany, traditional and indigenous medicines. One of the successful strategies for the investigation of new bioactive compounds from medicinal plants includes the screening of plant extract, fractions followed by the purification of the constituents and screening for biological activity. In the present study, the heartwood of desert plant Acacia raddiana Willd was screened for antifungal activity by Agar-well diffusion method against Aspergillus flavus, Aspergillus niger, Candida albicans, Penicillium chrysogenum and Trichophyton rubrum. The result obtained shows that heartwood extract and their fractions serve as an effective agent against selected fungi and efficiency is dependent upon the nature of fraction and vary with respect to specific fungi. The extract and fractions shows a wide antifungal potential against C. albicans. The findings suggest that the medicinal plant under investigation might be a reasonable solution for fungal infections especially against C. albicans.

Ethno medical knowledge and traditional use of Aristolochia bracteolata Lam. for malaria among local communities in Jubek State of South Sudan: A cross-sectional survey

ETHNOPHARMACOLOGICAL RELEVANCE

The recognized challenges to access conventional antimalarial medicines could have contributed to the extensive use of Aristolochia bracteolata Lam. (Aristolochiaceae)to manage malaria in South Sudan traditionally. However, the use and acquired experiences are notwell documented.

AIM OF THE STUDY

This study aimed to document the traditional use of A. bracteolata for malaria treatment and experiences among the local communities in Jubek State of South Sudan.

METHODS

We performed a cross-sectional study in four counties in Jubek State and interviewed 396 community members, including traditional healers, using a semi-structured questionnaire. Four focused group discussions (FGDs) were also conducted using the interviewer guide. The inclusion criteria were; adults 18 years and older, men andwomen participants, at least one year residing in the study area before the study, and those with a history of medicinal plant use. Data were summarized and presented as proportions. Qualitative data were analyzed using a thematic content approach. The major themes that emerged were discussed. We applied the Pearson Chi-Square test at α = 0.05 to test the study's significant differences in responses. The statistical package for social sciences version 21 software was used for data analysis.

RESULTS

Women accounted for 208 (52.5%) of participants, with the majority 321 (81.1%) were between 18 and 45 years. Interestingly, most 312 (78.8%) had formal education. Moreover, about 208 (52.5%) participants collect the plant in their vicinity, where leaves were the most commonly used part 277 (46.4%), followed by the roots, seeds, and stems at 245(41.0%), 71 (11.9%), and 4 (0.7%), respectively. Furthermore, about 63 (15.9%) of the participants experienced side effects, including early abortions, heartburns, sweating, and stomach discomforts. Conversely, a total of 387 (96.0%) reported getting cured of malaria. Generally, the quantity of medicine taken per day differs concerning parts of the plant, with leaves ranging from 1 to 10 pieces, roots at 0.4-1 g, and seeds at 0.1-0.5 g. The locals used these plant parts to prepare infusion and decoction traditional dosage forms for oral use.

CONCLUSION

The documented medicinal plant's therapeutic uses provided critical information on the traditional use of A. bracteolata by the community in Jubek state of South Sudan to treat malaria. Although most users reported getting cured of malaria, a notable proportion of them experienced side effects, including early-stage abortion and stomach discomforts. Thus, the use of A. bracteolata preparations, particularly in pregnant women, should be avoided. Finally, further studies are needed to devise a strategy to neutralize the toxic compounds and create community awareness on best practices to minimize side effects.

Antiplasmodial, antimalarial activities and toxicity of African medicinal plants: a systematic review of literature

BACKGROUND

Malaria still constitutes a major public health menace, especially in tropical and subtropical countries. Close to half a million people mainly children in Africa, die every year from the disease. With the rising resistance to frontline drugs (artemisinin-based combinations), there is a need to accelerate the discovery and development of newer anti-malarial drugs. A systematic review was conducted to identify the African medicinal plants with significant antiplasmodial and/or anti-malarial activity, toxicity, as wells as assessing the variation in their activity between study designs (in vitro and in vivo).

METHODS

Key health-related databases including Google Scholar, PubMed, PubMed Central, and Science Direct were searched for relevant literature on the antiplasmodial and anti-malarial activities of African medicinal plants.

RESULTS

In total, 200 research articles were identified, a majority of which were studies conducted in Nigeria. The selected research articles constituted 722 independent experiments evaluating 502 plant species. Of the 722 studies, 81.9%, 12.4%, and 5.5% were in vitro, in vivo, and combined in vitro and in vivo, respectively. The most frequently investigated plant species were Azadirachta indica, Zanthoxylum chalybeum, Picrilima nitida, and Nauclea latifolia meanwhile Fabaceae, Euphorbiaceae, Annonaceae, Rubiaceae, Rutaceae, Meliaceae, and Lamiaceae were the most frequently investigated plant families. Overall, 248 (34.3%), 241 (33.4%), and 233 (32.3%) of the studies reported very good, good, and moderate activity, respectively. Alchornea cordifolia, Flueggea virosa, Cryptolepis sanguinolenta, Zanthoxylum chalybeum, and Maytenus senegalensis gave consistently very good activity across the different studies. In all, only 31 (4.3%) of studies involved pure compounds and these had significantly (p = 0.044) higher antiplasmodial activity relative to crude extracts. Out of the 198 plant species tested for toxicity, 52 (26.3%) demonstrated some degree of toxicity, with toxicity most frequently reported with Azadirachta indica and Vernonia amygdalina. These species were equally the most frequently inactive plants reported. The leaves were the most frequently reported toxic part of plants used. Furthermore, toxicity was observed to decrease with increasing antiplasmodial activity.

CONCLUSIONS

Although there are many indigenous plants with considerable antiplasmodial and anti-malarial activity, the progress in the development of new anti-malarial drugs from African medicinal plants is still slothful, with only one clinical trial with Cochlospermum planchonii (Bixaceae) conducted to date. There is, therefore, the need to scale up anti-malarial drug discovery in the African region.

Mining Sudanese Medicinal Plants for Antiprotozoal Agents

Neglected tropical diseases are major health hazards in developing countries. Annually, up to 30 million people are affected by either Chagas disease, African trypansomiasis or leishmaniasis, and more than 200 million by malaria. Most of the currently available drugs have drawbacks in terms of toxicity, limited oral availability, development of resistance, or non-affordability. Tropical plants of the arid zones are a treasure chest for the discovery of bioactive secondary metabolites. This study aims to compile Sudanese medicinal plants, validate their antiprotozoal activities, and identify active molecules. We have performed a survey of medicinal plants of Sudan and selected 62 that are being used in Sudanese traditional medicine. From these, we collected materials such as leaves, stem, bark, or fruit. The plant materials were extracted in 70% ethanol and further fractionated by liquid-liquid partitioning using solvents of increasing polarity. This resulted in a library of 235 fractions. The library was tested in vitro against Plasmodium falciparum (erythrocytic stages), Trypanosoma brucei rhodesiense (bloodstream forms), Trypanosoma cruzi (intracellular amastigotes), and Leishmania donovani (axenic amastigotes). Active fractions were also tested for cytotoxicity. Of the 235 fractions, 125 showed growth inhibitory activity >80% at 10 μg/ml, and >50% at 2 μg/ml against at least one of the protozoan parasites. Plasmodium falciparum was the most sensitive of the parasites, followed by T. b. rhodesiense and L. donovani. Only few hits were identified for T. cruzi, and these were not selective. Contrary to expectation based on phylogeny, but in agreement with previous results, a large number of extracts displayed mutual activity against T. brucei and P. falciparum. HPLC-based activity profiling for selected active extracts was performed to identify the bioactive principles. Active compounds identified by dereplication were guieranone A from Guiera senegalensis J.F.Gmel.; pseudosemiglabrin from Tephrosia apollinea (Delile) DC; ellagic acid and quercetin from Terminalia leiocarpa (DC.) Baill.; and catechin, ethyl gallate, and epicatechin gallate from Vachellia nilotica (L.) P.J.H.Hurter & Mabb. Also the extracts of Croton gratissimus var. gratissimus and Cuscuta hyalina Roth ex Schult. exhibited promising antitrypanosomatid activity. This assessment provides a comprehensive overview of Sudanese medicinal plants and supports the notion that they are a potential source of bioactive molecules against protozoan parasites.

Forest Fevers: traditional treatment of malaria in the southern lowlands of Laos

ETHNOPHARMACOLOGICAL RELEVANCE

Malaria is still a highly challenging public health issue in southern Lao PDR, with increasing cases of artemisinin resistance and Plasmodium vivax infections which are more complicated to treat. Traditional medicine has a long history of use in Laos, and is primarily practised by traditional village healers, who possess unique bodies of transmitted knowledge focused on herbal prescriptions, including those for the treatment of malaria. Villagers also use plants for healthcare in the home. The aim of the study is to document local fever concepts and use of herbal remedies, and examine whether they may have potential as complementary treatments against malaria.

MATERIALS AND METHODS

The study took place in Champasak province in the far south of Laos, in primarily lowland areas. First, 35 traditional healers across the 10 districts of the province were interviewed to elicit details about knowledge and treatment of fevers. Second, a household survey was conducted in a village in a malaria-endemic area; 97 households were interviewed on fever incidence, differentiation, treatment-seeking behaviour and knowledge of plant-based remedies for fevers. Plants indicated by both healers and villagers were collected and voucher specimens deposited in the herbarium of the National University of Laos for identification.

RESULTS

Malaria is a well-known pathology among the healers and villagers of lowland Champasak province; biomedical treatments are preferentially used, but traditional medicine is a popular complementary method, especially in chronic cases with additional symptoms. 30 different fever types were recorded, which were usually named symptomatically, and grouped into 12 categories. Some were described as forms of malaria, which was conceived as a dynamic, changing pathology affecting many body systems. Healers formulate treatments based on symptoms and the person's constitution, and with the intention of creating specific pharmacological actions associated with temperature or flavours. 11 of the healers gave prescriptions for malaria (27 in total), including 47 identified plant species. The most-used plants (4 or more use-reports) were also the most cited in the literature for use against malaria, demonstrating a correspondence between Lao healers and other traditional medical systems. Furthermore, some of these species show promising results for future research, especially Amorphophallus paeniifolius (Dennst.) Nicolson and Alocasia macrorrhizos (L.) G. Don.

CONCLUSION

Traditional healers are important actors in the treatment of malaria in southern Laos, and herbal remedies should be evaluated further by the use of reverse treatment outcome trials, especially those which may be of use as complementary remedies in treating P. vivax. Initiatives on knowledge transmission, medicinal plant conservation and healthcare integration are also urgently needed.

Kostchyienones A and B, new antiplasmodial and cytotoxicity of limonoids from the roots of Pseudocedrela kotschyi (Schweinf.) Harms

Two new limonoids, kostchyienones A (1) and B (2), along with 12 known compounds 3-14 were isolated from the roots of Pseudocedrela kostchyi. Compound (7) was isolated for the first time from a natural source. Their structures were elucidated on the basis of spectroscopic evidence. Compounds 1-6 and 13-14 gave IC50 values ranging from 0.75 to 5.62 μg/mL for antiplasmodial activity against chloroquine-sensitive (Pf3D7) and chloroquine-resistant (PfINDO) strains of Plasmodium falciparum. Compound 5 showed moderate potential cytotoxicity against the HEK239T cell line with an IC50 value of 22.2±0.89 μg/mL. The antiplasmodial efficacy of the isolated compounds supports the medicinal value of this plant and its potential to provide novel antimalarial drugs.

Potential therapeutic applications of the genus Annona: Local and traditional uses and pharmacology

ETHNO-PHARMACOLOGICAL RELEVANCE

Annona species (Annonaceae) have long been used as traditional herbal medicines by native peoples in tropical areas. In different countries they are used against a large variety of illnesses, such as parasitic and infectious diseases, cancer, diabetes, peptic ulcers, and mental disorders.

AIM OF THE STUDY

This review aims to achieve a comprehensive understanding of the research conducted so far on the local and traditional uses, pharmacological activities, mechanism of actions of active compounds, toxicity, and possible interactions with other drugs of the Annona species. Through analysis of these findings, evidences supporting their applications in ethno-medicines are described. We discuss the possible research opportunities and stand out the weak points in our knowledge that deserves further investigation.

MATERIAL AND METHODS

Information on ethno-medicinal uses and pharmacological activities of the Annona genus was collected. The main scientific biomedical literature databases (Cochrane, PubMed, Scopus, Lilacs, SeCiMed, Elsevier, SpringerLink, Google Scholar, SciFinder) were consulted. The search covered all the literature available until September 2017. National and regional databases of Herbal Medicine and Complementary and Alternative Medicine were also revised in order to explore further data. For a better understanding of the therapeutic importance of these species, we have classified the pharmacological activities within each group of disorders. The International Classification of Diseases (ICD), used from WHO Member States, was chosen as the reference classification.

RESULTS

From among the 27 species revised, four species are highlighted for their important pharmacological activities in most of the groups of illnesses: A. muricata, A. squamosa, A. senegalensis, and A. cherimola. Many investigations have been performed with extracts from the leaves, bark, fruit and seeds and have shown a wide range of pharmacological activities, such as antiprotozoal, antitumoural, antidiabetic, hepato-protective, anti-inflammatory and anxiolytic activities. The chemistry on the annonaceous acetogenins (ACGs) has been extensively investigated due to their potent antitumoural activity. Many of the assays were carried out with the isolated acetogenins in different lines of tumour culture cells and were found effective at very low doses even in multidrug-resistant tumours, and hence constitute promising compounds in the treatment of different types of cancers. No studies were found with extracts rich in acetogenins in the clinical field.

CONCLUSIONS

The experimental results from the pharmacological research enable the validation of their traditional uses in several of the groups of diseases in the countries of origin and reveal these plants to be a valuable source for therapeutic molecules. However, more toxicity assays and clinical trials would be necessary to establish optimal and safe doses of consumption on the application of these medicinal plants.

Hydroethanolic Extracts of Erigeron floribundus and Azadirachta indica Reduced Plasmodium berghei Parasitemia in Balb/c Mice

Malaria is one of the most important infectious diseases in Africa especially in Cameroon. The nonaccessibility to current treatments for poor people and the appearance of drug-resistant Plasmodium falciparum parasites stimulate the search for alternative treatments. The aim of this study was to evaluate the antimalarial activity and the safety of hydroethanolic extracts from Erigeron floribundus and Azadirachta indica. The crude hydroethanolic extracts of E. floribundus (HEEF) and A. indica (HEAI) were prepared via maceration of the whole plant powder of E. floribundus and the leaves of A. indica in 70% ethanol. The antimalarial activity was determined according to Peter's 4-day suppressive test using the murine model Plasmodium berghei/Balb C mice, while the acute and subacute toxicity tests were assessed according to the OECD 425 and 407 guidelines, respectively. The results indicate a reduction of parasitemia ranging from 49.75 ± 3.64 to 69.28 ± 1.36% for HEAI and from 30.46 ± 4.30 to 62.36 ± 2.32% for HEEI. Overall, HEEF and HEAI at doses of 60, 120, and 240 mg/kg b.w. and 75, 150, and 300 mg/kg b.w., respectively, showed a significant (p≤0.001) parasitemia reduction on P. berghei infecting BALB/c mice. HEEF and HEAI caused a significant (p<0.001) attenuation of body temperature drop in mice compared to negative control, except for the 150 mg/kg b.w. dose in the female group. Moreover, there was no mice mortality observed with these extracts even at 5000 mg/kg, while the aspartate amino transferase (ASAT) level of mice treated with 300 mg/kg b.w. of HEAI extract increased when compared with the control. The results of this study support the traditional use of these plants species extracts against malaria infection in rural zones of Northern Cameroon, therefore confirming their potential as sources for the development of efficient phytomedicines for malaria-poverty disease alleviation.

A Review on Annona squamosa L.: Phytochemicals and Biological Activities

Annona squamosa L. (Annonaceae) is a fruit tree with a long history of traditional uses. A. squamosa is an evergreen plant mainly located in tropical and subtropical regions. Srikayas, the fruits of A. squamosa, are extensively used to prepare candies, ice creams and beverages. A wide range of ethno-medicinal uses has been related to different portions of A. squamosa, such as tonic, apophlegmatisant, cool medicine, abortient and heart sedative. Numerous research projects on A. squamosa have found that it has anticancer, anti-oxidant, antidiabetic, antihypertensive, hepatoprotective, antiparasitic, antimalarial, insecticidal, microbicidel and molluscicidal activities. Phytochemistry investigations on A. squamosa have considered annonaceous acetogenins (ACGs), diterpenes (DITs), alkaloids (ALKs) and cyclopeptides (CPs) as the main constituents. Until 2016, 33 DITs, 19 ALKs, 88 ACGs and 13 CPs from this species were reported. On the basis of the multiple researches on A. squamosa, this review strives to integrate available information on its phytochemicals, folklore uses and bioactivities, hoping to promote a better understanding of its medicinal values.

Multipurpose effectiveness of Couroupita guianensis-synthesized gold nanoparticles: high antiplasmodial potential, field efficacy against malaria vectors and synergy with Aplocheilus lineatus predators

Mosquito-borne diseases represent a deadly threat for millions of people worldwide. According to recent estimates, about 3.2 billion people, almost half of the world's population, are at risk of malaria. Malaria control is particularly challenging due to a growing number of chloroquine-resistant Plasmodium and pesticide-resistant Anopheles vectors. Newer and safer control tools are required. In this research, gold nanoparticles (AuNPs) were biosynthesized using a cheap flower extract of Couroupita guianensis as reducing and stabilizing agent. The biofabrication of AuNP was confirmed by UV-vis spectrophotometry, Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), energy-dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD), zeta potential, and particle size analysis. AuNP showed different shapes including spheres, ovals, and triangles. AuNPs were crystalline in nature with face-centered cubic geometry; mean size was 29.2-43.8 nm. In laboratory conditions, AuNPs were toxic against Anopheles stephensi larvae, pupae, and adults. LC50 was 17.36 ppm (larva I), 19.79 ppm (larva II), 21.69 ppm (larva III), 24.57 ppm (larva IV), 28.78 ppm (pupa), and 11.23 ppm (adult). In the field, a single treatment with C. guianensis flower extract and AuNP (10 × LC50) led to complete larval mortality after 72 h. In standard laboratory conditions, the predation efficiency of golden wonder killifish, Aplocheilus lineatus, against A. stephensi IV instar larvae was 56.38 %, while in an aquatic environment treated with sub-lethal doses of the flower extract or AuNP, predation efficiency was boosted to 83.98 and 98.04 %, respectively. Lastly, the antiplasmodial activity of C. guianensis flower extract and AuNP was evaluated against CQ-resistant (CQ-r) and CQ-sensitive (CQ-s) strains of Plasmodium falciparum. IC50 of C. guianensis flower extract was 43.21 μg/ml (CQ-s) and 51.16 μg/ml (CQ-r). AuNP IC50 was 69.47 μg/ml (CQ-s) and 76.33 μg/ml (CQ-r). Overall, our results showed the multipurpose effectiveness of C. guianensis-synthesized AuNPs, since they may be proposed as newer and safer tools in the fight against CQ-r strains of P. falciparum and for field control of malaria vectors, in synergy with wonder killifish predators.

Medicinal Plants Used in Mali for the Treatment of Malaria and Liver Diseases

Today, ethno-pharmacology is a very important resource in order to discover new therapies for the current diseases. Moreover, another good justification for the ethno-pharmacological approach is to obtain new, effective, less expensive and simple therapies, limiting at the same time the cost of pharmaceutical research. Two major anti-malarial drugs widely used today, i.e. quinine and artemisinin, came respectively from Peruvian and Chinese ancestral treatments reported in the traditional medicines. In this contest, there is an urgent need for the discovery of new drugs, due to the critical epidemiological situation of this disease and to the growth of resistances. In Mali, malaria and liver diseases remain one of the leading public health problems. Many medicinal plants are often used, in local traditional medicine, for the treatment at the same time of malaria and liver diseases, including hepatic syndromes, jaundice, hepatitis and other hepatic disorders. Moreover, in the local language Bamanan, the word “ Sumaya” is used both for malaria and some liver diseases. In addition, we noted that some of the improved traditional phytomedicines produced by the Department of Traditional Medicine are prescribed by modern doctors both for malaria and liver diseases. In this review, pharmacological, toxicological and phytochemical data on Argemone mexicana L. (Papaveraceae), Cochlospermum tinctorium Perr. ex A. Rich (Cochlospermaceae), Combretum micranthum G.Don (Combretaceae), Entada africana Guillet Perr. (Mimosaceae), Erythrina senegalensis A. DC (Fabaceae), Mitragyna inermis (Willd) Kuntze (Rubiaceae), Nauclea latifolia Smith syn. Sarcocephalus latifolius (Smith) Bruce (Rubiaceae), Securidaca longepedunculata Fresen (Polygalaceae), Trichilia emetica Vahl. (Meliaceae), and Vernonia colorata (Willd) Drake (Asteraceae) are reported. Some of the collected data could be used to improve the actual herbal drugs and to propose new phytomedicines for the management of malaria and liver diseases.

Antiplasmodial potential of traditional phytotherapy of some remedies used in treatment of malaria in Meru-Tharaka Nithi County of Kenya

ETHNOPHARMACOLOGICAL RELEVANCE

Medicinal plants play a major role in many communities across the world, in the treatment and prevention of disease and the promotion of general health. The aim of the study was to escalate documentation from an earlier study of medicinal plants, traditionally used to combat malaria by the Ameru community of Imenti Forest area and Gatunga in Eastern Region of Kenya, and validate their ethnopharmacological claims by evaluating their antiplasmodial efficacies.

MATERIALS AND METHODS

The study was carried out in Meru County at Imenti Forest Game Reserve and in Tharaka Nithi County at Gatunga. Traditional health practitioners (THP) were interviewed with a standard questionnaire to obtain information on medicinal plants traditionally used for management of malaria. Group interviews were also held among THPs and members of the community. The antiplasmodial activities of the crude extracts against chloroquine sensitive (D6) and resistant (W2) Plasmodium falciparum were determined using the semi-automated micro-dilution technique that measures the ability of the extracts to inhibit the incorporation of (G-3H) hypoxanthine into the malaria parasite.

RESULTS

Ninety nine (99) species in eighty one (81) genera and forty five (45) families were documented and evaluated for in vitro antiplasmodial activity. Compositae, Fabaceae, Meliceae, Rubiaceae, Rutaceae and Verbenaceae had the highest number of species mentioned in treatment of malaria in Meru/Tharaka Nithi study area. Twenty four (24.2%) species showed antiplasmodial efficacy of IC50 ≤ 5 µg/ml and were considered to have potential for isolation of antimalarial compounds. Eight plant (8) species with moderate antiplasmodial activity namely; Cordia africana, Commiphora africana, Elaeodendron buchananii, Gomphocarpus semilunatus, Tarena graveolens, Plectranthus igniarius, Acacia senegal and Ziziphus abyssinica were documented from this region for the first time for the treatment of malaria. The antiplasmodial activity of MeOH root bark extract of Maytenus obtusifolia was very promising (IC50 < 1.9 µg/ml) and this is the first report on traditional use of M. obtusifolia for treatment of malaria and antimalarial activity.

CONCLUSIONS

The results seem to indicate that ethnopharmacological inquiry used in search for new herbal remedies as predictive and could be used as the basis for search of new active principles. Eight plant (8) species are documented from this region for the first time for the treatment of malaria. This is the first report on traditional use of M. obtusifolia for treatment of malaria and evaluation of its antiplasmodial activity.

Fern-synthesized nanoparticles in the fight against malaria: LC/MS analysis of Pteridium aquilinum leaf extract and biosynthesis of silver nanoparticles with high mosquitocidal and antiplasmodial activity

Malaria remains a major public health problem due to the emergence and spread of Plasmodium falciparum strains resistant to chloroquine. There is an urgent need to investigate new and effective sources of antimalarial drugs. This research proposed a novel method of fern-mediated synthesis of silver nanoparticles (AgNP) using a cheap plant extract of Pteridium aquilinum, acting as a reducing and capping agent. AgNP were characterized by UV-vis spectrophotometry, Fourier transform infrared (FTIR) spectroscopy, energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). Phytochemical analysis of P. aquilinum leaf extract revealed the presence of phenols, alkaloids, tannins, flavonoids, proteins, carbohydrates, saponins, glycosides, steroids, and triterpenoids. LC/MS analysis identified at least 19 compounds, namely pterosin, hydroquinone, hydroxy-acetophenone, hydroxy-cinnamic acid, 5, 7-dihydroxy-4-methyl coumarin, trans-cinnamic acid, apiole, quercetin 3-glucoside, hydroxy-L-proline, hypaphorine, khellol glucoside, umbelliferose, violaxanthin, ergotamine tartrate, palmatine chloride, deacylgymnemic acid, methyl laurate, and palmitoyl acetate. In DPPH scavenging assays, the IC50 value of the P. aquilinum leaf extract was 10.04 μg/ml, while IC50 of BHT and rutin were 7.93 and 6.35 μg/ml. In mosquitocidal assays, LC50 of P. aquilinum leaf extract against Anopheles stephensi larvae and pupae were 220.44 ppm (larva I), 254.12 ppm (II), 302.32 ppm (III), 395.12 ppm (IV), and 502.20 ppm (pupa). LC50 of P. aquilinum-synthesized AgNP were 7.48 ppm (I), 10.68 ppm (II), 13.77 ppm (III), 18.45 ppm (IV), and 31.51 ppm (pupa). In the field, the application of P. aquilinum extract and AgNP (10 × LC50) led to 100 % larval reduction after 72 h. Both the P. aquilinum extract and AgNP reduced longevity and fecundity of An. stephensi adults. Smoke toxicity experiments conducted against An. stephensi adults showed that P. aquilinum leaf-, stem-, and root-based coils evoked mortality rates comparable to the permethrin-based positive control (57, 50, 41, and 49 %, respectively). Furthermore, the antiplasmodial activity of P. aquilinum leaf extract and green-synthesized AgNP was evaluated against CQ-resistant (CQ-r) and CQ-sensitive (CQ-s) strains of P. falciparum. IC50 of P. aquilinum were 62.04 μg/ml (CQ-s) and 71.16 μg/ml (CQ-r); P. aquilinum-synthesized AgNP achieved IC50 of 78.12 μg/ml (CQ-s) and 88.34 μg/ml (CQ-r). Overall, our results highlighted that fern-synthesized AgNP could be candidated as a new tool against chloroquine-resistant P. falciparum and different developmental instars of its primary vector An. stephensi. Further research on nanosynthesis routed by the LC/MS-identified constituents is ongoing.

Potential antimalarials from African natural products: A reviw

Malaria remains an overwhelming infectious disease with significant health challenges in African and other endemic countries globally. Resistance to antimalarial drugs has become one of the most momentous challenges to human health, and thus has necessitated the hunt for new and effective drugs. Consequently, few decades have witnessed a surfeit of research geared to validate the effectiveness of commonly used traditionally medicines against malaria fever. The present review work focuses on documenting natural products from African whose activity has been reported in vivo or in vitro against malaria parasite. Literature was collected using electronic search of published articles (Google Scholar, PubMed, Medline, Sciencedirect, and Science domain) that report on antiplasmodial activity of natural products from differernts Africa region. A total of 652 plant taxa from 146 families, 134 isolated antimalarial compounds from 39 plants species, 2 herbal formulations and 4 insect/products were found to be reported in literature from 1996 to 2015. Plants species from family Asteraceae (11.04%), Fababceae (8.128%), Euphorbiaceae (5.52%), Rubiaceas (5.52%), and Apocyanaceae (5.214%), have received more scientific validation than others. African natural products possess remarkable healing properties as revealed in the various citations as promising antimalarial agents. Some of these natural products from Africa demonstrate high, promising or low activities against Plasmodium parasite. This study also shows that natural products from Africa have a huge amount of novel antimalarial compounds that could serve as a leads for the development of new and effective antiplasmodial drugs. However, in a view of bridging the gap in knowledge, clinical validation of these natural products are of paramount importance.

Antiplasmodial potential of traditional antimalarial phytotherapy remedies used by the Kwale community of the Kenyan Coast

ETHNOPHARMACOLOGICAL RELEVANCE

In Kenya, 22 million people are at risk of malaria, 70% of them are in rural areas and most of these people use traditional plant based medicines to treat malaria. The aim of the study was to escalate documentation, from an earlier study of medicinal plants, traditionally used to treat malaria by the Digo community of Kwale County, taking cognizance of their pharmacological information by evaluating their antiplasmodial efficacies.

MATERIALS AND METHODS

The study was carried out in Kwale County at Shimba Hills Game Reserve and adjoining part of Kinango. Traditional health practitioners (THP) were interviewed with a standard questionnaire to obtain information on medicinal plants traditionally used for management of malaria. Group interviews were also held among THPs and members of the community. The plant samples collected were tested for antiplasmodial activity against chloroquine sensitive (D6) and resistant (W2) Plasmodium falciparum using the ability of extracts, prepared from the plant species, to inhibit the incorporation of [G-3H] hypoxanthine into the malaria parasites.

RESULTS

Fifty seven (57) species in forty eight (48) genera and thirty (30) families were documented and evaluated for in vitro antiplasmodial activity. Apocynaceae, Euphorbiaceae, and Rubiaceae families had each about 12% of the plant species reported as antimalarial remedy and represented the species that are most commonly used. Twelve species (21.1%) showed antiplasmodial efficacy of IC50<5µg/ml and these were Boscia salicifolia, Cissampelos mucronata, Clerodendrum myricoides, Commiphora schimperi, Flueggea virosa, Maytenus undata, Maytenus senegalensis, Maytenus putterlickioides, Vernonia amygdalina, Warburgia stuhlmannii, Zanthoxylum chalybeum and Tabernaemontana pachysiphon.

CONCLUSIONS

These results seem to indicate that ethnopharmacological inquiry used in search for new herbal remedies as predictive and could form the basis of an ethnopharmacopoeia and search for new active principles. This is the first report on traditional use of T. pachysiphon for malaria and its antiplasmodial activity.

Antiplasmodial activity of medicinal plants from Chhotanagpur plateau, Jharkhand, India

BACKGROUND

The alarmingly increasing problem of drug resistance in treatment of malaria has led to an urgent need for identifying new anti-malarial drugs for both prophylaxis and chemotherapy.

AIM OF THE STUDY

The present study presents a systematic exploration of the ex vivo blood stage antiplasmodial potential of medicinal plants to corroborate their traditional usage against malaria in Jharkhand, India.

METHODS

An ethnobotanical survey in and around Ranchi was done to grasp the traditional knowledge of medicinal plants used by local healers for malaria, other fevers and for other medicinal purposes like, antiamoebic, antihelmenthic, antidote to poisons, etc. Following the survey, the selected 22 plant samples were extracted in ethanol for studying ex vivo SYBR Green I fluorescence assay based anti-plasmodial activity against both chloroquine-sensitive Pf3D7 and chloroquine resistant PfINDO strains of Plasmodium falciparum grown in human red blood cell cultures. Cytotoxicity was determined against HeLa and L929 cells using MTT assay. Further the most potent extract was chromatographed on reverse phase HPLC towards antiplasmodial activity guided purification of metabolites.

RESULTS

Of the 22 plant species assayed, the highest antiplasmodial activity (Pf3D7IC50 ≤ 5 µg/ml) was seen in leaf ethanol extracts of Corymbia citriodora (Hook.) K.D.Hill & L.A.S.Johnson, Calotropis procera (Aiton) Dryand. and Annona squamosa L. and bark ethanol extract of Holarrhena pubescens Wall. ex G.Don. Leaf ethanol extract of H. pubescens, bark ethanol extract of Pongamia pinnata (L.) Pierre and whole plant ethanol extract of Partheniumhysterophorus L. showed promising activity (IC50 6-10 µg/ml). Good antiplasmodial activity (IC50: 11-20 µg/ml) was observed in leaf ethanol extract of Bryophyllum pinnatum (Lam.) Oken and whole plant ethanol extract of Catharanthus roseus (L.) G.Don. The extracts of plants showing highest to good antiplasmodial activity exhibited HeLa/Pf3D7 selectivity indices of the order of 20-45. Bioassay guided fractionation of P. hysterophorus led to fivefold enrichment of antiplasmodial activities (IC50 ~450 ng/ml) in some fractions.

CONCLUSION

These results provide confirmation to the traditional usage of some medicinal plants against malaria in areas around Ranchi, Jharkhand.

In vivo antiplasmodial and toxicological effect of Maytenus senegalensis traditionally used in the treatment of malaria in Tanzania

Background

In Tanzania and elsewhere, medicinal plants, including Maytenus senegalensis, are still widely used in the treatment of malaria and other ailments. The aim of the present study was to investigate the in vivo antiplasmodial and toxic effects in mice.

Methods

Oral antiplasmodial and acute toxicity of the ethanolic root extract of M. senegalensis was evaluated in mice. The Peters 4-day in vivo antiplasmodial effect against early rodent malaria infection in chloroquine-sensitive Plasmodium berghei NK 65 strain in mice.

Results

The M. senegalensis extract was found non-toxic and the oral median lethal dose in mice was determined to be greater than 1,600 mg/kg body weight. The findings revealed a significant (P = 0.001) daily increase in the level of parasitaemia in the parasitized untreated groups and a significant (P < 0.001) dose dependent decrease in parasitaemia in the parasitized groups treated with varying doses ranging from 25 to 100 mg/kg body weight of M. senegalensis extract and the standard drug sulphadoxine/pyrimethamine at 25/1.25 mg/kg body weight. Overall, the dose dependent parasitaemia suppression effects were in the order of: 25/1.25 mg/kg body weight of sulphadoxine/pyrimethamine > 100 mg/kg > 75 mg/kg > 50 mg/kg > 25 mg/kg body weight of M. senegalensis extract.

Conclusion

The implications of these findings is that M. senegalensis ethanolic root bark extract possess potent antiplasmodial effect and may, therefore, serve as potential sources of safe, effective and affordable anti-malarial drugs. The displayed high in vivo antiplasmodial activity and lack of toxic effect render M. senegalensis a candidate for the bioassay-guided isolation of compounds which could develop into new lead structures and candidates for drug development programmes against human malaria.

Biosynthesis of Silver Nanoparticles Using Plant Extract and its Anti-Plasmodial Property

Metallic nanoparticles have received great attention from chemists, physicists, biologists and engineers who wish to use them for the development of a new generation of nanodevices. In the present Communication, a completely “green” chemistry method for producing silver nanoparticles is introduced. The process is simple, environmentally benign, and quite efficient. Green nanoparticle synthesis has been achieved using environmentally acceptable plant extract and ecofriendly reducing and capping agents. In particular, silver nanoparticles are proved to have potential antibacterial, antifungal and antiplasmodial and antimicrobial properties. The present study was aimed to identify the antiplasmodial activity of green synthesised silver nanoparticles (AgNPs) using aqueous extract of plantEuphorbia hirtaagainstP.falciparum. Nanoparticles are being used in many commercial applications. It was found that aqueous silver ions can be reduced by aqueous extract of plant to generate extremely stable silver nanoparticles in water. The bio-reduced silver nanoparticles were appropriately characterized by UV–vis spectrum, Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The formation of the AgNPs synthesized from the XRD spectrum compared with the standard confirmed spectrum of silver particles formed in the present experiments were in the form of nanocrystals, as evidenced by the peaks at 2θ values of =28.01°, 32.41°, 46.44°, 55.05° and 57.75°. The scanning electron micrograph (SEM) showed structures of spherical, cubic shape, and the size range was found to be 30–60 nm. The EDX spectra showed the purity of the material and the complete chemical composition of the synthesized AgNPs. The parasitic inhibition was dose-dependent. The synthesized AgNPs showed considerable antiplasmodial activity than the crude methanol and aqueous leaf extract ofE.hirta. The maximum efficacy was

New neolignan glycoside and an unusual benzoyl malic acid derivative from Maytenus senegalensis leaves

Further investigation of the methanol leaf extract of Maytenus senegalensis led to the isolation of six compounds, including mayselignoside (1) and an unusual benzoyl malic acid derivative, benzoyl R-(+)-malic acid (2). Two known lignan derivatives (+)-lyoniresinol (3) and (-)-isolariciresinol (4), a known neolignan derivative dihydrodehydrodiconiferyl alcohol (5) and the triterpenoid, β-amyrin (6) were also isolated. The structures of these compounds were elucidated by a combination of 1D and 2D NMR and mass spectroscopy. All compounds were tested for cytotoxicity against mouse lymphoma cell line (L5178Y) and for antimicrobial activity against strains of bacteria and fungi. None of the compounds showed promising cytotoxic and/or antimicrobial activities.

The uniqueness and therapeutic value of natural products from West African medicinal plants. Part I: uniqueness and chemotaxonomy

This review gives an in depth coverage of the natural products derived from West African medicinal plants with diverse biological activities.

Ethnobotanical survey on medicinal plants used by Guinean traditional healers in the treatment of malaria

ETHNOPHARMACOLOGICAL RELEVANCE

The objective of the present study was to collect and document information on herbal remedies traditionally used for the treatment of malaria in Guinea.

MATERIALS AND METHODS

The survey was carried out from May 2008 to September 2010 and targeted traditional medical practitioners and herbalists. The questionnaire and oral interviews were based on the standardized model which was prepared by the "Centre de Recherche et de Valorisation des Plantes Médicinales (CRVPM) - Dubréka".

RESULTS AND DISCUSSION

A total of 258 people (141 males and 117 females) from which 150 traditional healers and 108 herbalists were interviewed. The age of informants ranged from 28 to 82 years old. 57% (149/258) of the interviewees were more than 50 years old. The respondents had good knowledge of the symptoms of malaria, and a fairly good understanding of the causes. One hundred thirteen plant species were recorded, out of which 109 were identified. They belonged to 84 genera and 46 families. The most frequently cited plants were Vismia guineensis, Parkia biglobosa, Nauclea latifolia, Harungana madagascariensis, Terminalia macroptera, Crossopteryx febrifuga, Terminalia albida, Annona senegalensis, and Nauclea pobeguinii. The leaves were most frequently used (80/113 species), followed by stem bark (38/113 species) and roots (4/113 species). The remedies were mostly prepared by decoction (111 species), followed by maceration (seven species). Only one species was prepared by infusion.

CONCLUSION

The present study showed that traditional healers in Guinea have a consistent knowledge of antimalarial plants. Further research should be carried out to compare the anti-malarial activity of the different species, and to check if their use against malaria can be scientifically validated.

Azadirachta indica ethanolic extract protects neurons from apoptosis and mitigates brain swelling in experimental cerebral malaria

BACKGROUND

Cerebral malaria is a rapidly developing encephalopathy caused by the apicomplexan parasite Plasmodium falciparum. Drugs currently in use are associated with poor outcome in an increasing number of cases and new drugs are urgently needed. The potential of the medicinal plant Azadirachta indica (Neem) for the treatment of experimental cerebral malaria was evaluated in mice.

METHODS

Experimental cerebral malaria was induced in mice by infection with Plasmodium berghei ANKA. Infected mice were administered with Azadirachta indica ethanolic extract at doses of 300, 500, or 1000 mg/kg intraperitoneally (i.p.) in experimental groups, or with the anti-malarial drugs chloroquine (12 mg/kg, i.p.) or artemether (1.6 mg/kg, i.p.), in the positive control groups. Treatment was initiated at the onset of signs of brain involvement and pursued for five days on a daily basis. Mice brains were dissected out and processed for the study of the effects of the extract on pyramidal cells' fate and on markers of neuroinflammation and apoptosis, in the medial temporal lobe.

RESULTS

Azadirachta indica ethanolic extract mitigated neuroinflammation, decreased the severity of brain oedema, and protected pyramidal neurons from apoptosis, particularly at the highest dose used, comparable to chloroquine and artemether.

CONCLUSIONS

The present findings suggest that Azadirachta indica ethanolic extract has protective effects on neuronal populations in the inflamed central nervous system, and justify at least in part its use in African and Asian folk medicine and practices.

Ethnoknowledge of Bukusu community on livestock tick prevention and control in Bungoma district, western Kenya

ETHNOPHARMACOLOGICAL RELEVANCE

To date, nomadic communities in Africa have been the primary focus of ethnoveterinary research. The Bukusu of western Kenya have an interesting history, with nomadic lifestyle in the past before settling down to either arable or mixed arable/pastoral farming systems. Their collective and accumulative ethnoveterinary knowledge is likely to be just as rich and worth documenting.

AIM OF THE STUDY

The aim of the present study was to document indigenous knowledge of the Bukusu on the effect of livestock ticks and ethnopractices associated with their management. It was envisaged that this would provide a basis for further research on the efficacy of these practices that could also lead to the discovery of useful tick-control agents.

MATERIALS AND METHODS

Non-alienating, dialogic, participatory action research (PAR) and participatory rural appraisal (PRA) approaches involving 272 women and men aged between 18 and 118 years from the Bukusu community were used.

RESULTS

Ticks are traditionally classified and identified by colour, size, host range, on-host feeding sites, and habitat preference. Tick-associated problems recognised include kamabumba (local reference to East Coast fever, Anaplasmosis or Heartwater diseases transmitted by different species of livestock ticks) and general poor performance of livestock. Traditional methods of controlling ticks include handpicking, on-host use of ethnobotanical suspensions (prepared from one or more of over 150 documented plants) to kill the ticks and prevent re-infestation, fumigation of infested cattle with smoke derived from burning ethnobotanical products, burning pastures, rotational grazing ethnopractices, and livestock quarantine.

CONCLUSIONS

The study confirms that the Bukusu have preserved rich ethnoveterinary knowledge and practices. It provides some groundwork for elucidating the efficacy of some of these ethnopractices in protecting livestock from tick disease vectors, particularly those involving the use of ethnobotanicals, which may lead to the discovery of useful ant-tick agents.

Ethnomedical study and iron content of some medicinal herbs used in traditional medicine in Cote d'Ivoire for the treatment of anaemia

Medicinal plants have been a source of succour in the control of many diseases in developing countries and anaemia is no exception. In this study, ethnomedical survey was carried out for recording medicinal plants used in Northern and South-Eastern Côte d'Ivoire against anaemia. Also iron content was determined for some of the recorded plants using phenanthroline method. Thirty (30) medicinal plants, covering 28 genera and 22 families were recorded. These plants were used to prepare 30 receipts for the treatment of anaemia and aggravating factors such as malaria and gastro-intestinal helminthes. Eleven (11) of these medicinal plants showed presence of iron in various quantities. The most promising were Tectona grandis, Amaranthus spinosus and Stylosanthes erecta which contained the highest iron contents viz; 266.6, 236.6 and 206.6 mg/100 g respectively. They were followed by Hoslundia opposita, Imperata cylindrica, Cajanus cajan, Thalia geniculata and Milicia excelsa. These results lend credence to the traditional use of these plants in Cote d'Ivoire's ethnomedicine for the treatment of anaemia.

Medicinal plants traditionally used in Mali for dysmenorrhea

Dysmenorrhea is painful menstrual cramps, which negatively impacts the quality of life of a large percentage of the world's female population in reproductive age. The paper reviews the plants used in the Malian traditional medicine for the treatment of dysmenorrhea. Some medicinal plants were effective for treatments of dysmenorrhea with minimal side effects. Conventional therapy for dysmenorrhea, which usually includes non-steroidal anti-inflammatory drugs (NSAIDs), provides symptomatic relief, but presents increasing adverse effects with long-term use. This article is in the framework of a study supported by International Foundation for Science (IFS) on three medicinal plants used in the treatment of dysmenorrhea in Mali: Maytenus senegalensis Stereospermum kunthianum and Trichilia emetica.

Ethnodiagnostic skills of the digo community for malaria: a lead to traditional bioprospecting

Malaria is a major public health problem that is presently complicated by the development of resistance by Plasmodium falciparum to the mainstay drugs. Thus, new drugs with unique structures and mechanism of action are required to treat drug-resistant strains of malaria. Historically, compounds containing a novel structure from natural origin represent a major source for the discovery and development of new drugs for several diseases. This paper presents ethnophytotherapeutic remedies, ethnodiagnostic skills, and related traditional knowledge utilized by the Digo community of the Kenyan Coast to diagnose malaria as a lead to traditional bioprospecting. The current study was carried out in three Digo villages of Diani sub-location between May 2009 and December 2009. Data was collected using semi-structured interviews, and open and close-ended questionnaires. A total of 60 respondents (34 men and 26 women) provided the targeted information. The results show that the indigenous knowledge of Digo community on malaria encompasses not only the symptoms of malaria but also the factors that are responsible for causing malaria, attributes favoring the breeding of mosquitoes and practices employed to guard against mosquito bites or to protect households against malaria. This knowledge is closely in harmony with scientific approaches to the treatment and control of the disease. The Digo community uses 60 medicinal plants distributed in 52 genera and 27 families to treat malaria. The most frequently mentioned symptoms were fever, joint pains, and vomiting while the most frequently mentioned practices employed to guard against mosquito bites and/or to protect households against malaria was burning of herbal plants such as Ocimum suave and ingestion of herbal decoctions and concoctions. The Digo community has abundant ethnodiagnostic skills for malaria which forms the basis of their traditional bioprospecting techniques.

Icacina senegalensis (Icacinaceae), traditionally used for the treatment of malaria, inhibits in vitro Plasmodium falciparum growth without host cell toxicity

Background

With the aim of discovering new natural active extracts against malaria parasites, Icacina senegalensis was selected after an ethnopharmacological survey conducted on plants used in traditional malaria treatment in Senegal.

Methods

Different concentrations of the plant extract and fractions were tested on synchronized Plasmodium falciparum cultures at the ring stage using the parasite lactate dehydrogenase assay. Their haemolytic activity and in vitro cytoxicity were evaluated. The chromatographic profiles of active fractions were also established.

Results

The plant extract and fractions revealed anti-plasmodial activity (IC₅₀ < 5 μg/mL) with no toxicity (Selectivity indexes >10). The dichloromethane fraction showed stronger anti-plasmodial activity than the total extract.

Conclusion

Anti-plasmodial activity and toxicity of I. senegalensis are reported for the first time and showed promising results in malaria field research.

Potential antimalarials from Nigerian plants: a review

Malaria, caused by parasites of the genus Plasmodium, is one of the leading infectious diseases in many tropical regions, including Nigeria, a West African country where transmission occurs all year round. Many of the inhabitants use plants as remedies against fever and other symptoms of acute malaria, as reported herein. Some of these plants have their antimalarial efficacies scientifically demonstrated and the active compounds isolated with their probable mechanisms of action studied. Medicinal plants are used to treat diseases also where the biodiversity of plants occur in parallel with endemic transmission of malaria. This review focuses on medicinal plants which are used to treat malaria in Nigeria, and on antimalarial testing of extracts and purified compounds from plants. Some show intense activity against malaria parasites in vitro and in experimentally infected mice. The search for new drugs based on plants is important due to the emergence and widespread of chloroquine-resistant and multiple drug-resistant malaria parasites, which require the development of new antimalarials. An acquaintance with antimalarial plants may be a springboard for new phytotherapies that could be affordable to treat malaria, especially among the less privileged native people living in endemic areas of the tropics, mostly at risk of this devastating disease.

Anti-malarial herbal remedies of northeast India, Assam: an ethnobotanical survey

ETHNOPHARMACOLOGICAL RELEVANCE

Malaria is a serious public health problem in the north-eastern region of India including Assam, in view of development of chloroquine resistant Plasmodium falciparum. There is need for alternative and affordable therapy.

AIM OF THE STUDY

This study was conducted to document indigenous knowledge, usage customs and practices of medicinal plant species traditionally used by the residents of Sonitpur district of Tezpur, Assam to treat malaria and its associated symptoms.

MATERIALS AND METHODS

A total of 50 randomly selected sampling represented by male (38.76%) and female respondents (12.24%) were interviewed using a semi-structured questionnaire.

RESULTS

The present ethno-botanical survey revealed 22 species of plants belonging to 17 botanical families were reported to be used exclusively in this region for the treatment of malaria. Verbenaceae (three species), Menispermaceae (two species), and Acanthaceae (two species) botanical families represented the species that are most commonly cited in this survey work and the detailed use of plants has been collected and described.

CONCLUSIONS

The most serious threat to the existing knowledge and practice on traditional medicinal plants included cultural change, particularly the influence of modernization and lack of interests shown by the next younger generations were the main problems reported by the informants during the field survey. Hence, the proper documentation of traditional medicinal plants being used as anti-malarial agents and related indigenous knowledge held by the tribal community is an important approach to control the spread of vector-borne diseases like malaria reported in this survey work.

Maytenus heterophylla and Maytenus senegalensis, two traditional herbal medicines

Maytenus heterophylla (Eckl. and Zeyh.) N.K.B. Robson and Maytenus senegalensis (Lam.) Exell are two African shrubs or trees that go under the common name of spike thorn, which belong to the Celastraceae family. Different plant parts of this species are largely used in traditional medicine for infectious and inflammatory diseases treatment. Several studies have been reported for both these species, but there are no recent review articles focusing microscopic, phytochemistry and pharmacological studies. The aim of this review is to summarize the information about these two African traditional medicines. Such kind of data can be applied in future experimental work and may guide future studies, namely in the field of validation of traditional medicine.

Traditional herbal medicine in far-west Nepal: a pharmacological appraisal

BACKGROUND

Plant species have long been used as principal ingredients of traditional medicine in far-west Nepal. The medicinal plants with ethnomedicinal values are currently being screened for their therapeutic potential but their data and information are inadequately compared and analyzed with the Ayurveda and the phytochemical findings.

METHODS

The present study evaluated ethnomedicinal plants and their uses following literature review, comparison, field observations, and analysis. Comparison was made against earlier standard literature of medicinal plants and ethnomedicine of the same area, the common uses of the Ayurveda and the latest common phytochemical findings. The field study for primary data collection was carried out from 2006-2008.

RESULTS

The herbal medicine in far-west Nepal is the basis of treatment of most illness through traditional knowledge. The medicine is made available via ancient, natural health care practices such as tribal lore, home herbal remedy, and the Baidhya, Ayurveda and Amchi systems. The traditional herbal medicine has not only survived but also thrived in the trans-cultural environment with its intermixture of ethnic traditions and beliefs. The present assessment showed that traditional herbal medicine has flourished in rural areas where modern medicine is parsimoniously accessed because of the high cost and long travel time to health center. Of the 48 Nepalese medicinal plants assessed in the present communication, about half of the species showed affinity with the common uses of the Ayurveda, earlier studies and the latest phytochemical findings. The folk uses of Acacia catechu for cold and cough, Aconitum spicatum as an analgesic, Aesculus indica for joint pain, Andrographis paniculata for fever, Anisomeles indica for urinary affections, Azadirachta indica for fever, Euphorbia hirta for asthma, Taxus wallichiana for tumor control, and Tinospora sinensis for diabetes are consistent with the latest pharmacological findings, common Ayurvedic and earlier uses.

CONCLUSIONS

Although traditional herbal medicine is only a primary means of health care in far-west Nepal, the medicine has been pursued indigenously with complementing pharmacology and the Ayurveda. Therefore, further pharmacological evaluation of traditional herbal medicine deserves more attention.

Traditional antimalarial phytotherapy remedies used by the South Coast community, Kenya

AIM OF THE STUDY

This study was conducted to document herbal medicines used in the treatment of malaria as well as the existing knowledge, attitudes and practices related to malaria recognition, control and treatment in South Coast, Kenya.

METHODS

Data was collected using semistructured questionnaires and interviews. A focused group discussion held with the community members, one in each of the study villages supplemented the interview and questionnaire survey.

RESULTS

The respondents were found to have a good understanding of malaria and could distinguish it from other fever types. They were also aware that malaria was spread by mosquitoes. Malaria prevalence was high, and affected individuals an average of four times a year. Community members avoided mosquito bites by using mosquito nets, clearing bushes around their homesteads and burning plant parts to generate smoke. They prevented and treated malaria by taking decoctions or concoctions of traditional herbal remedies. Forty plant species in thirty-five genera distributed in twenty-four families were used as antimalarials in the study area. Five plant species, namely; Heeria insignis Del. (Anacardiaceae), Rottboelia exaltata L.F (Gramineae), Pentanisia ouranogyne S. Moore (Rubiaceae), Agathisanthenum globosum (A. Rich) Hiern (Rubiaceae), and Grewia trichocarpa Hochst ex A. Rich (Tiliaceae) are documented for the first time in South Coast, Kenya, for the treatment of malaria.

CONCLUSIONS

The plants documented in the current study are a potential source for new bioactive compounds of therapeutic value in malaria treatment. The results provide data for further pharmacological and toxicological studies and development of commercial antimalarial phytotherapy products.

In vivo anti-inflammatory effect and toxicological screening of Maytenus heterophylla and Maytenus senegalensis extracts

Maytenus heterophylla (Eckl & Zeyh.) Robson and Maytenus senegalensis (Lam). Exell are two African medicinal plants used to treat painful and inflammatory diseases. We evaluated the in vivo (per os) anti-inflammatory activity of M. heterophylla leaf, stem and root extracts and of M. senegalensis leaf and stem extracts. Additionally, we assessed their in vivo acute and sub-acute toxicities. Anti-inflammatory activities of ethanol extracts were determined in Wistar albino rats, by the carrageenan-induced paw oedema method. Acute and sub-acute toxicity screening of the extracts was evaluated in adult male CD-6 mice. Leaf extracts of M. heterophylla and M. senegalensis exhibited significant anti-inflammatory activity (120 mg/kg, per os), reducing oedema by 51% and 35%, respectively. While M. heterophylla extracts at 1200 mg/kg have shown to be non-toxic, M. senegalensis extracts indicated some toxicity. Our results show a significant anti-inflammatory effect of both M. heterophylla and M. senegalensis leaf extracts in a local model of acute inflammation and suggest the absence of acute and sub-acute toxicity signs of the M. heterophylla leaf extract (but not of M. senegalensis). Ongoing studies will surely shed some light into the mechanism of action of this active extract and establish its chemical fingerprint.