Toxicology of some important medicinal plants in southern Africa

Rare Earth and Platinum Group Elements In Sub-Saharan Africa and Global Health: The Dark Side of the Burgeoning of Technology

Despite steady progress in the development and promotion of the circular economy as a model, an overwhelming proportion of technological devices discarded by the Global North still finds its way to the Global South, where technology-related environmental health problems start from the predation of resources and continue all the way to recycling and disposal. We reviewed literature on TCEs in sub-Saharan Africa (SSA), focussing on: the sources and levels of environmental pollution; the extent of human exposure to these substances; their role in the aetiology of human diseases; their effects on the environment. Our review shows that even minor and often neglected technology-critical elements (TCEs), like rare earth elements (REEs) and platinum group elements (PGEs), reveal the environmental damage and detrimental health effects caused by the massive mining of raw materials, exacerbated by improper disposal of e-waste (from dumping to improper recycling and open burning). We draw attention of local research on knowledge gaps such as workable safer methods for TCE recovery from end-of-life products, secondary materials and e-waste, environmental bioremediation and human detoxification. The technical and political shortcomings in the management of TCEs in SSA is all the more alarming against the background of unfavourable determinants of health and a resulting higher susceptibility to diseases, especially among children who work in mines and e-waste recycling sites or who reside in dumping sites.This paper demonstrates, for the first time, that the role of unjust North-South dynamics is evident even in the environmental levels of minor trace elements and that the premise underlying attempts to solve the problem of e-waste dumped in Africa through recycling and disposal technology is in fact misleading. The influx of foreign electrical and electronic equipments should be controlled and limited by clearly defining what is a 'useful' second-hand device and what is e-waste; risks arising from device components or processing by-products should be managed differently, and scientific uncertainty and One Health thinking should be incorporated in risk assessment.

The ethnomedicine, phytochemistry, and pharmacological properties of the genus Bersama: current review and future perspectives

Bersama (Melianthaceae) has been used in traditional medicine for a wide range of ailments, including blood purifier, immune booster, psychotropic medication, and treatment for malaria, hepatitis, infertility, diabetes, impotency, meningitis, and stroke. This review gathers fragmented information from the literature on ethnomedicinal applications, phytochemistry, pharmacology, and toxicology of the Bersama genus. It also explores the therapeutic potential of the Bersama genus in ethnophytopharmacology, allowing for further investigation. All the available information published in the English language on Bersama genus was compiled from electronic databases such as Academic Journals, Ethnobotany, Google Scholar, PubMed, Science Direct, Web of Science, and library search using the following keywords: "Bersama genus," "traditional use," "phytochemistry," "pharmacological effects," and "toxicology". The ethnomedical applications of the Bersama genus have been recorded, and it has been used traditionally for more than 30 different types of ailments. Thus far, more than 50 compounds have been isolated from the genus. Cardiac glycosides and terpenoids are the main compounds isolated from the Bersama genus. Different plant parts of Bersama genus extracts demonstrated a wide range of pharmacological properties, including antioxidant, antimalarial, antidiabetic, antiviral, anti-inflammatory, and cytotoxic activity. Exemplary drug leads from the genus include mangiferin and quercetin-3-O-arabinopyranoside, both of which have antioxidant activities. Bersama genus has long been used to cure a wide range of ailments. Bersama genus extracts and phytochemicals have been found to have promising pharmacological activities. Further study on promising crude extracts and compounds is required to develop innovative therapeutic candidates.

Inhibition of pro-inflammatory cytokines by selected southern African medicinal plants in LPS-stimulated RAW 264.7 macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

Bark is frequently used in southern African traditional medicine to treat inflammation, yet it remains to be rigorously examined for its immunological and anti-inflammatory activity.

AIM OF THE STUDY

Barks obtained from ten important and popular southern Africa plants were evaluated for their anti-inflammatory and immunomodulatory properties against the secretion of some pro-inflammatory cytokines (interleukin (IL)-1β, IL-6, tumour necrosis factor-α (TNF-α), and interferon-gamma (IFN-γ) as well as chemokines (monocyte chemoattractant protein 1 (MCP-1) and macrophage inflammatory protein (MIP)-2) in murine RAW 264.7 macrophages.

MATERIALS AND METHODS

The inhibitory effects of aqueous and ethanol extracts were determined using cytokine multiplex-bead assays in lipopolysaccharide (LPS)-stimulated and unstimulated RAW 264.7 cells.

RESULTS

Overall, the ethanol extracts were more potent cytokine inhibitors compared to the aqueous extracts. The LPS-stimulated cells treated with the ethanol extracts of Erythrina lysistemon Hutch., Pterocelastrus rostratus Walp. Syzygium cordatum Hochst. ex Krauss and Warburgia salutaris (G. Bertol.) Chiov., demonstrated significant (p < 0.005) inhibition up to 85% of IL-1β, IL-6, and TNF-α secretion compared to the LPS control. Additionally, P. rostratus and S. cordatum aqueous bark extracts substantially decreased the secretion of all the tested cytokines and chemokines. Chemical investigation of the S. cordatum extract resulted in the identification of four ellagic acid derivatives: ellagic acid 4-O-α-rhamnopyranoside (1), ellagic acid 4-O-α-4″-acetylrhamnopyranoside (2), 3-O-methylellagic acid 4'-O-α-3″-O-acetylrhamnopyranoside (3) and 3-O-methylellagic acid 4'-O-α-4″-O-acetylrhamnopyranoside (4), along with mixtures of ellagic acid 4-O-α-2″-acetylrhamnopyranoside (5), ellagic acid 4-O-α-3″-acetylrhamnopyranoside (6) and ellagic acid (7). Their structures were confirmed by mass spectrometry, NMR spectroscopy, and comparison with data from literature.

CONCLUSION

The cytokine inhibition properties of most of the medicinal plants screened herein are reported for the first time. Our results provide insights into the mechanism of action by which the selected southern African medicinal plants regulate inflammation.

Pharmacological and toxicological effects of Amaryllidaceae

The Amaryllidaceae family is widely distributed in the tropics, presenting biological activity attributed mostly to alkaloids, such as an important inhibitory activity of acetylcholinesterase (AChE), antifungal, antibacterial, and cytotoxic activities. The present study aims to review the spectrum of action of the main biological activities and toxicity of secondary metabolites found in Amaryllidaceae through a literature review, using Prisma and the descriptors "Pharmacological effects of Amaryllidaceae" and "Amaryllidaceae family" and "Pharmacological actions of Amaryllidaceae", used in English and Portuguese. The literature search was done in March and May 2023. Original works published from 2012 to 2023, available in full, and presenting experimental and clinical studies were included. After the selection considering the inclusion and exclusion criteria, 60 articles fulfilled the defined criteria. From a pharmacological point of view, the highlight is due to the alkaloid galantamine, which has the potential- and is already used - for treating Alzheimer's. The toxicological aspect must be considered and evaluated carefully, as alkaloids have been associated with adverse effects such as nausea, vomiting, diarrhea, abdominal pain, and cardiovascular, neurological, and respiratory changes. Furthermore, some studies indicate that consuming these plants in significant quantities can lead to hepatic and renal toxicity. Therefore, the therapeutical use of this family's plant drugs and derivatives requires further studies to elucidate its effects and point out metabolites with therapeutic potential.

A Systematic Review of Curtisia dentata Endemic to South Africa: Phytochemistry, Pharmacology, and Toxicology

The use of traditional medicine in treating a variety of both human and animal infections is ancient and still relevant. This is due to the resistance exhibited by most pathogenic microbial stains to currently-used antibiotics. The current work reports the phytochemistry, ethno-medicinal uses, toxicology, and most important pharmacological activities that validate the use of the plant species in African traditional medicine. Curtisia dendata is used in the treatment of many human and animal infections, including diarrhea, skin and related conditions, sexually transmitted infections, cancer, and a variety of ethno-veterinary infections. Pharmacologically, the plant species exhibited potent antimicrobial activity against a variety of pathogens. Further, both extracts and compounds isolated from the plant species exhibited potent antioxidant, anticancer, anti-parasitic, anti-inflammatory, and other important biological activities. Phytochemically, the plant species possess a variety of compounds, particularly triterpenes, that may well explain the various pharmacological activities of the plant species. The toxicological parameters, antimicrobial activities against microorganisms related to sexually transmitted infections, anti-diabetic effects, and inflammatory properties of the plant species are not well studied and still need to be explored. The biological activities observed validate the use of the plant species in African traditional medicine, particularly in the treatment of pulmonary infections associated with Mycobacterium species, and may well be due to the presence of triterpenes prevalent in the leaves.

Bowiea volubilis: From "Climbing Onion" to Therapeutic Treasure-Exploring Human Health Applications

Bowiea volubilis subsp. volubilis is primarily used to address human respiratory infections, coughs, and colds due to its diverse pharmaceutical properties. Notably, the plant contains alkaloids that exhibit notable antifungal, antibacterial, and cytotoxic properties. Additionally, the presence of saponins, with recognized antioxidant and anticancer attributes, further contributes to its medicinal potential. Steroid compounds inherent to the plant have been associated with anti-inflammatory and anticancer activities. Moreover, the bulb of B. volubilis has been associated as a source of various cardiac glycosides. Despite these therapeutic prospects, B. volubilis remains inedible due to the presence of naturally occurring toxic substances that pose risks to both animals and humans. The review focuses on a comprehensive exploration concerning B. volubilis ethnobotanical applications, phytochemical properties, and diverse biological activities in relation to in vitro and in vivo applications for promoting human health and disease prevention. The aim of the study is to comprehensively investigate the phytochemical composition, bioactive compounds, and potential medicinal properties of Bowiea volubilis, with the ultimate goal of uncovering its therapeutic applications for human health. This review also highlights an evident gap in research, i.e., insufficient evidence-based research on toxicity data. This void in knowledge presents a promising avenue for future investigations, opening doors to expanded inquiries into the properties and potential applications of B. volubilis in the context of human diseases.

Ethnomedicines for the treatment of scorpion stings: A perspective study

ETHNOPHARMACOLOGICAL RELEVANCE

Scorpion sting is a public health concern with limited clinical symptomatic treatment. The clinical treatment uses anti-scorpion antivenom and prazosin (α-adrenergic inhibitor), often in combination with insulin, to reduce scorpion venom-induced hyperglycemia and other complications. However, these therapies also possess some limitations, necessitating urgent exploration of ethnomedicines, mainly traditional medicinal plants, to treat scorpion stings. Unfortunately, several conventional treatments are not scientifically validated, thus raising questions about their quality and utility. Therefore, pharmacological re-assessment of such medicinal plants to alleviate scorpion stings' complications is essential.

AIM OF THE STUDY

The principal objectives of this study are to provide a brief overview of medically important scorpions of the world, outline the extant traditional practices, and comprehensively review plants used in conventional ethnic medicines to treat scorpion stings over time. Modern technological advances in identifying and characterizing plant bioactive molecules are also mentioned in this review.

MATERIALS AND METHODS

The traditionally used medicinal plants against scorpion stings were reviewed from the available literature in the database. The Plant List (http://www.theplantlist.org/) was used to validate the scientific names of the plants mentioned in this study. The search targeted literature on conventional treatments and crude plant extracts or their bioactive components with proven neutralization capacity against scorpion stings. Search words used were 'scorpion sting,' 'treatment for a scorpion sting,' 'antivenom and scorpion sting,' 'traditional treatment for scorpion stings, and 'natural compounds against scorpion stings'.

RESULTS

A list of more than 200 medicinal plants traditionally used in several countries for treating scorpion stings is presented in this review. Though some myth-based remedies are practiced to treat scorpion stings, no empirical evidence exists to validate this aspect of traditional knowledge. Only 38 traditional medicinal plant extracts have been tested under in-vivo and in-vitro conditions to determine their neutralization potency of scorpion envenomation. Although a few bioactive plant constituents showing scorpion venom neutralization potency have been characterized, they are not yet commercially available for clinical application.

CONCLUSIONS

There is tremendous potential locked in medicinal plants' traditional knowledge for scorpion envenomation treatment. Translating this knowledge into the clinical application will require pharmacological reassessment, in tandem with isolation and characterization of active compounds to prove their prophylactic prowess. Almost equally important would be the formulation of stringent strategies to conserve such medicinal plants from overexploitation.

Toxic Elemental Impurities in Herbal Weight Loss Supplements; A Study Using ICP-OES Microwave-Assisted Digestion

The tendency of using weight loss herbal preparations is continuously increasing, especially for the widespread consumption of junk food that is characterized by high calories. Weight loss herbal preparations are considered a type of food supplement product, and, as such, the regulations governing their quality control might be minimal. These products could be locally formulated in any country or internationally imported. Being non-controlled products, the herbal weight-loss products may contain high levels of elemental impurities that might exceed the permissible ranges. Moreover, these products contribute to the total daily intake (TDI) of such elements, which might represent concerns about their potential toxicological danger. In this research, the elemental contents in such products were investigated. The inductively coupled plasma with optical emission spectrometer (ICP-OES) was used to determine the levels of 15 elemental contents, namely, Na, K, Ca, Mg, Al, Cu, Fe, Li, Mn, As, Co, Cr, Cd, Ni and Pb. The results showed that seven micro-elements, namely Cd, Co, Ni, Cr, Pb, Li and Cu, were either not detectable or at a concentration much lower than their tolerable limits. However, all studied macro-elements (Na, K, Ca and Mg), together with Fe, were found at considerable, yet safe levels. On the other hand, Mn, Al and As contents showed perturbing levels in some of the studied products. Finally, a conclusion was highlighted for the necessity for stricter surveillance of such herbal products.

Essential oils from Dysphania genus: Traditional uses, chemical composition, toxicology, and health benefits

The genus Dysphania belongs to the Amaranthaceae family and is known for its many health benefits. Therefore, it is commonly available worldwide and includes more than 47 species, five species have been mainly reported, and D. ambrosioides has been one of the most widely used plants for thousands of years as a remedy for a wide range of ailments. In recent investigations, the essential oils of the genus Dysphania have been examined for their antibacterial, antioxidant, and antiviral properties related to specific components such as terpenoid compounds that exhibit pharmacological activity. Moreover, some of Dysphania's compounds show a toxicological effect. Therefore, the objective of the study was to provide EO chemical composition and pharmacological data of the genus Dysphania.

Medicinal plants used for the management of respiratory diseases in Zimbabwe: Review and perspectives potential management of COVID-19

Respiratory diseases have in the recent past become a health concern globally. More than 523 million cases of coronavirus disease (COVID19), a recent respiratory diseases have been reported, leaving more than 6 million deaths worldwide since the start of the pandemic. In Zimbabwe, respiratory infections have largely been managed using traditional (herbal) medicines, due to their low cost and ease of accessibility. This review highlights the plants' toxicological and pharmacological evaluation studies explored. It seeks to document plants that have been traditionally used in Zimbabwe to treat respiratory ailments within and beyond the past four decades. Extensive literature review based on published papers and abstracts retrieved from the online bibliographic databases, books, book chapters, scientific reports and theses available at Universities in Zimbabwe, were used in this study. From the study, there were at least 58 plant families comprising 160 medicinal plants widely distributed throughout the country. The Fabaceae family had the highest number of medicinal plant species, with a total of 21 species. A total of 12 respiratory ailments were reportedly treatable using the identified plants. From a total of 160 plants, colds were reportedly treatable with 56, pneumonia 53, coughs 34, chest pain and related conditions 29, asthma 25, tuberculosis and spots in lungs 22, unspecified respiratory conditions 20, influenza 13, bronchial problems 12, dyspnoea 7, sore throat and infections 5 and sinus clearing 1 plant. The study identified potential medicinal plants that can be utilised in future to manage respiratory infections.

Sub-acute toxicity study on hydromethanolic leaves extract of Combretum hypopilinum (Combretaceae) Diels in Wistar rats

The plant Combretum hypopilinum Diels (Combretaceae) has been utilized in Nigeria and other African nations to treat many diseases including liver, inflammatory, gastrointestinal, respiratory, infectious diseases, epilepsy and many more. Pharmacological investigations have shown that the plant possesses anti-infective, antidiarrhoeal, hepatoprotective, anti-inflammatory, anticancer, sedative, antioxidant, and antiepileptic potentials. However, information on its toxicity profile is unavailable despite the plant's therapeutic potential. As such, this work aimed to determine the acute and sub-acute oral toxic effects of the hydromethanolic leaves extract of C. hypopilinum. The preliminary phytochemical evaluation was carried out based on standard procedures. The acute toxicity evaluation was conducted by oral administration of the extract at the dose of 5000 mg/kg based on the guideline of the Organization of Economic Co-operation and Development (OECD) 423. To investigate the sub-acute toxicity effects, the extract was administered orally to the animals daily for 28-consecutive days at the doses of 250, 500, and 1000 mg/kg. Mortality, body weight and relative organ weight were observed. The hepatic, renal, haematological, and lipid profile parameters were investigated. The liver, kidney, heart, lung, small intestine, and stomach were checked for any histopathological alterations. The results of the phytochemical investigation showed cardiac glycosides, tannins, steroids, flavonoids, alkaloids, saponins, and triterpenes. Based on the acute toxicity investigation outcome, no death and signs of toxic effects were observed. The result showed that the oral median lethal dose (LD50) of the extract was more than the 5000 mg/kg. The extract remarkably reduced the weekly body weight of the animals at 500 mg/kg in the first and second weeks. It also significantly decreased the relative kidney weight, alkaline phosphatase, glucose, potassium, and low-density lipoprotein. There was a remarkable elevation in the percentage of eosinophils, basophils, monocytes, and granulocyte. There were histopathological abnormalities on the kidney, lung, stomach, and small intestine. The extract is relatively safe on acute exposure but moderately toxic at higher doses on sub-acute administration, particularly to the kidney.

Antidepressant Effects of South African Plants: An Appraisal of Ethnobotanical Surveys, Ethnopharmacological and Phytochemical Studies

Globally, the search for safe and potent natural-based treatment for depression is receiving renewed interest given the numerous side-effects associated with many existing drugs. In South Africa, the use of plants to manage depression and related symptoms is fairly documented among different ethnic groups. In the current study, we reviewed existing ethnobotanical, ethnopharmacological and phytochemical studies on South African medicinal plants used to manage depression. Electronic databases were accessed for scientific literature that meets the inclusion criteria. Plants with ethnobotanical evidence were subjected to a further pharmacological review to establish the extent (if any) of their effectiveness as antidepressants. Critical assessment resulted in 20 eligible ethnobotanical records, which generated an inventory of 186 plants from 63 plant families. Due to the cultural differences observed in the definition of depression, or lack of definition in some cultures, most plants are reported to treat a wide range of atypical symptoms related to depression. Boophone disticha, Leonotis leonurus and Mentha longifolia were identified as the three most popular plants, with over eight mentions each from the ethnobotanical records. The dominant families were Asteraceae (24), Fabaceae (16), Amaryllidaceae (10), and Apocynaceae (10) which accounted for about 32% of the 186 plants. Only 27 (≈14.5%) of the plants have been screened for antidepressant activity using in vitro and in vivo models. Agapanthus campanulatus, Boophone disticha, Hypericum perforatum, Mondia whitei and Xysmalobium undulatum, represent the most studied plants. Phytochemical investigation on nine out of the 27 plants revealed 24 compounds with antidepressant-like effects. Some of these included buphanidrine and buphanamine which were isolated from the leaves of Boophone disticha, Δ⁹-tetrahydrocannabinol, cannabidiol and cannabichromene obtained from the buds of Cannabis sativa and carnosic acid, rosmarinic acid and salvigenin from Rosmarinus officinalis, A significant portion (≈85%) of 186 plants with ethnobotanical records still require pharmacological studies to assess their potential antidepressant-like effects. This review remains a valuable reference material that may guide future ethnobotanical surveys to ensure their robustness and validity as well as database to identify promising plants to screen for pharmacology efficacy.

Ethnobotany and Toxicity Status of Medicinal Plants with Cosmeceutical Relevance from Eastern Cape, South Africa

The indigenous people of the Eastern Cape residing within the richest plant biodiversity in the world, including Africa’s floral ‘gold mine’, have a long history of plant use for skincare. However, such rich flora comes with numerous plants that have the potential to cause harm to humans through their usage. Therefore, the study was aimed at documenting the toxicity status of important medicinal plants used by the indigenous people from the Eastern Cape for skincare and supported by literature for cosmeceutical relevance. A list of plants used for skincare was produced following an ethnobotanical survey. In addition, data on the level of toxicity and cosmeceutical relevance of plants listed from the survey were collected from literature resources. The study listed a total of 38 plants from 25 plant families, the majority being represented by the Asphodelaceae and Asteraceae, both at 13.2%. The most preferred plant parts were the leaves (60.4%) indicating sustainable harvesting practices by the community. The literature reports validated 70% of the medicinal plants surveyed for skincare were nontoxic. Most of the plants can be incorporated in the formulation of products intended for skincare due to their low toxicity and high cosmeceutical relevance.

Progress in Immunoassays of Toxic Alkaloids in Plant-Derived Medicines: A Review

Plants are the cradle of the traditional medicine system, assuaging human or animal diseases, and promoting health for thousands of years. However, many plant-derived medicines contain toxic alkaloids of varying degrees of toxicity that pose a direct or indirect threat to human and animal health through accidental ingestion, misuse of plant materials, or through the food chain. Thus, rapid, easy, and sensitive methods are needed to effectively screen these toxic alkaloids to guarantee the safety of plant-derived medicines. Antibodies, due to their inherent specificity and high affinity, have been used as a variety of analytical tools and techniques. This review describes the antigen synthesis and antibody preparation of the common toxic alkaloids in plant-derived medicines and discusses the advances of antibody-based immunoassays in the screening and detection of toxic alkaloids in plants or other related matrices. Finally, the limitations and prospects of immunoassays for toxic alkaloids are discussed.

Importance and Relevance of Phytochemicals Present in Galenia africana

Many people in developing countries rely primarily on medicinal plants as their main source of healthcare, particularly for the treatment of skin infections. Despite the widespread use of medicinal plants, there is a lack of literature describing the relevance and risks of exposure of the phytochemicals present. Galenia africana has been used traditionally in the form of pastes, decoctions, and lotions to treat wounds and other skin-related ailments. This is a report on the phytochemical composition of G. africana and a review on the pharmacological importance and relevance of these phytochemicals. The major groups of phytochemicals identified in G. africana extracts were aliphatics, aliphatic triterpenoids, fatty acids, flavonoids, and phenolic and tocopherol compounds. These have been found to exhibit medicinal properties, thus highlighting the need to assess the safety of G. africana for topical application. The information related to the safety of the various compounds could indicate the potential risks related to accidental intake of the extract upon topical product applications. This report concludes that the quantities of the phytochemicals present in G. africana should not cause undue risk to human health, which provides comfort to pursue future work on using and developing G. africana as a therapeutic agent.

Bulbous Plants Drimia: "A Thin Line between Poisonous and Healing Compounds" with Biological Activities

Drimia (synonym Urginea) plants are bulbous plants belonging to the family Asparagaceae (formerly the family Hyacinthaceae) and are distinctive, powerful medicinal plants. Just some species are indigenous to South Africa and have been traditionally utilized for centuries to cure various diseases and/or ailments. They have been recognized among the most famous and used medicinal plants in South Africa. Traditionally, the plants are used for various illnesses such as dropsy, respiratory disease, bone and joint complications, skin disorders, epilepsy and cancer. A number of studies have reported biological properties such as antiviral, antibacterial, antioxidant and anti-inflammatory, immunomodulatory, and anticancer activities. Their bulbs are a popular treatment for colds, measles, pneumonia, coughs, fever and headaches. However, some plant species are regarded as one of the six most common poisonous plants in Southern Africa that are toxic to livestock and humans. Due to the therapeutic effects of the Drimia plant bulb, research has focused on the phytochemicals of Drimia species. The principal constituents isolated from this genus are cardiac glycosides. In addition, phenolic compounds, phytosterols and other phytochemical constituents were identified. This study constitutes a critical review of Drimia species' bioactive compounds, toxicology, biological properties and phytochemistry, advocating it as an important source for effective therapeutic medicine. For this purpose, various scientific electronic databases such as ScienceDirect, Scopus, Google Scholar, PubMed and Web of Science were researched and reviewed to conduct this study. Despite well-studied biological investigations, there is limited research on the toxic properties and the toxic compounds of certain Drimia species. Searching from 2017 to 2021, Google Scholar search tools retrieved 462 publications; however, only 3 investigated the toxicity and safety aspects of Drimia. The aim was to identify the current scientific research gap on Drimia species, hence highlighting a thin line between poisonous and healing compounds, dotted across numerous publications, in this review paper.

South Africa's Best BARK Medicines Prescribed at the Johannesburg Muthi Markets for Skin, Gut, and Lung Infections: MIC's and Brine Shrimp Lethality

Indigenous trade of medicinal plants in South Africa is a multi-million-rand industry and is still highly relevant in terms of primary health care. The purpose of this study was to identify today's most traded medicinal barks, traditionally and contemporaneously used for dermatological, gastrointestinal, and respiratory tract infections; then, to investigate the antimicrobial activity and toxicity of the respective extracts and interpret outcomes in light of pharmacokinetics. Thirty-one popularly traded medicinal barks were purchased from the Faraday and Kwa Mai-Mai markets in Johannesburg, South Africa. Information on the medicinal uses of bark-based medicines in modern commerce was recorded from randomly selected traders. The minimum inhibitory concentration (MIC) method was used for antimicrobial screening, and brine shrimp lethality was used to determine toxicity. New medicinal uses were recorded for 14 bark species. Plants demonstrating some broad-spectrum activities against tested bacteria include Elaeodendron transvaalense, Erythrina lysistemon, Garcinia livingstonei, Pterocelastrus rostratus, Rapanea melanophloeos, Schotia brachypetala, Sclerocarya birrea, and Ziziphus mucronata. The lowest MIC value of 0.004 mg/mL was observed against Staphylococcus epidermidis for a dichloromethane bark extract of E. lysistemon. The tested medicinal barks were shown to be non-toxic against the Artemia nauplii (brine shrimp) bioassay, except for a methanol extract from Trichilia emetica (69.52% mortality). Bacterial inhibition of bark extracts with minimal associated toxicity is consistent with the safety and valuable use of medicinal barks for local muthi market customers. Antimicrobial outcomes against skin and gastrointestinal pathogens are feasible because mere contact-inhibition is required in vivo; however, MIC values against respiratory pathogens require further explaining from a pharmacokinetics or pharmacodynamics perspective, particularly for ingested rather than smoked therapies.

A comparative study of the HPLC-MS profiles and biological efficiency of different solvent leaf extracts of two African plants: Bersama abyssinica and Scoparia dulcis

In the present study, two medicinal plants from Africa, namely Bersama abyssinica Fresen. and Scoparia dulcis L., were extracted using ethyl acetate, methanol, and water. The antioxidant, enzyme (α-amylase, α-glucosidase, acetyl- and butyrylcholinesterase, lipase, and tyrosinase) inhibitory action, and phytochemical profiles of extracts of Bersama abyssinica and Scoparia dulcis were determined. The aqueous (180.62 and 61.81 mg gallic acid equivalent/g extract, for B. abyssinica and S. dulcis respectively) and methanol (75.21 and 57.81 mg rutin equivalent/g extract, for B. abyssinica and S. dulcis, respectively) extracts contained high concentrations of phenolic and flavonoids, respectively. The ethyl acetate extracts of both plants were potent inhibitors of α-glucosidase and tyrosinase. Several phytochemical groups were determined by HPLC-MS/MS. The study tend to suggest that B. abyssinica and S. dulcis are potential candidates for the development of novel therapeutical agents.

Antibacterial and Anticancer Activity and Untargeted Secondary Metabolite Profiling of Crude Bacterial Endophyte Extracts from Crinum macowanii Baker Leaves

This study isolated and identified endophytic bacteria from the leaves of Crinum macowanii and investigated the potential of the bacterial endophyte extracts as antibacterial and anticancer agents and their subsequent secondary metabolites. Ethyl acetate extracts from the endophytes and the leaves (methanol: dichloromethane (1 : 1)) were used for antibacterial activity against selected pathogenic bacterial strains by using the broth microdilution method. The anticancer activity against the U87MG glioblastoma and A549 lung carcinoma cells was determined by the MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxy-phenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay. Bacterial endophytes that were successfully isolated from C. macowanii leaves include Raoultella ornithinolytica, Acinetobacter guillouiae, Pseudomonas sp., Pseudomonas palleroniana, Pseudomonas putida, Bacillus safensis, Enterobacter asburiae, Pseudomonas cichorii, and Arthrobacter pascens. Pseudomonas cichorii exhibited broad antibacterial activity against both Gram-negative and Gram-positive pathogenic bacteria while Arthrobacter pascens displayed the least MIC of 0.0625 mg/mL. Bacillus safensis crude extracts were the only sample that showed notable cell reduction of 50% against A549 lung carcinoma cells at a concentration of 100 μg/mL. Metabolite profiling of Bacillus safensis, Pseudomonas cichorii, and Arthrobacter pascens crude extracts revealed the presence of known antibacterial and/or anticancer agents such as lycorine (1), angustine (2), crinamidine (3), vasicinol (4), and powelline. It can be concluded that the crude bacterial endophyte extracts obtained from C. macowanii leaves can biosynthesize bioactive compounds and can be bioprospected for medical application into antibacterial and anticancer agents.

Medicinal plants used for contraception in South Africa: A review

ETHNOPHARMACOLOGICAL RELEVANCE: The indigenous people of South Africa, such as the Khoisan, Zulu, and Ndebele, have used medicinal plants for contraception. One of the reasons for using contraception among indigenous communities is for child spacing.

AIM OF THE STUDY

The study aims to review medicinal plants used for contraception in South Africa as potential sources for the discovery and development of safe male and female hormonal contraceptives.

MATERIALS AND METHODS

A literature search was conducted on medicinal plants used for contraception in South Africa by referencing textbooks and scientific databases such as Google Scholar, Science Direct, PubMed, North-West University Institutional Repository, National ETD Portal, government policies and documents on contraception, theses and dissertations, and other web sources such as records from SANBI and PROTA.

RESULTS

A minimum of 25 medicinal plants were identified as being used for contraception in South Africa, and these plants included local and exotic plants. Medicinal plants with contraceptive activity are Bulbine latifolia, Pouzolzia mixta, Salsola tuberculatiformis, Securidaca longipedunculata, and Typha capensis. In vivo and in vitro studies showed a decrease in mount, intromission and ejaculatory frequencies, inhibition of implantation, contraceptive effect, displaced glucocorticoids, and prolonged diestrus or had negative effects on vitality, motility, and sperm production.

CONCLUSIONS

Some of the plants used for contraception in South Africa are toxic to both animals and humans. Research is needed focusing on medicinal plants used by men for contraception and by women for postcoital contraception in South Africa. Traditional healers must be included when drafting contraception policies and interventions. Medicinal plants such as B. latifolia and P. mixta demonstrated that medicinal plants used for contraception in South Africa are potential sources for the discovery and development of safe male and female hormonal contraceptives.

Plant lectins in cancer therapeutics: Targeting apoptosis and autophagy-dependent cell death

Plant lectins are non-immunoglobin in nature and bind to the carbohydrate moiety of the glycoconjugates without altering any of the recognized glycosyl ligands. Plant lectins have found applications as cancer biomarkers for recognizing the malignant tumor cells for the diagnosis and prognosis of cancer. Interestingly, plant lectins contribute to inducing cell death through autophagy and apoptosis, indicating their potential implication in cancer inhibitory mechanism. In the present review, anticancer activities of major plant lectins have been documented, with a detailed focus on the signaling circuit for the possible molecular targeted cancer therapy. In this context, several lectins have exhibited preclinical and clinical significance, driving toward therapeutic potential in cancer treatment. Moreover, several plant lectins induce immunomodulatory activities, and therefore, novel strategies have been established from preclinical and clinical investigations for the development of combinatorial treatment consisting of immunotherapy along with other anticancer therapies. Although the application of plant lectins in cancer is still in very preliminary stage, advanced high-throughput technology could pave the way for the development of lectin-based complimentary medicine for cancer treatment.

Plants Used by Bapedi Traditional Healers to Treat Asthma and Related Symptoms in Limpopo Province, South Africa

To the best of our knowledge there are presently no ethnobotanical surveys focusing on the utilisation of herbal remedies for asthma in South Africa. The present study is therefore an attempt to fill this gap in knowledge. A total of 140 Bapedi traditional healers (THs) practicing in the Capricorn, Sekhukhune, and Waterberg districts of the Limpopo Province (South Africa) were queried using semistructured questionnaires, supplemented by field observations during face-to-face interview. A total of 104 medicinal plant species (92 indigenous and 12 exotics) belonging to 92 genera, distributed across 54 botanical families, mostly the Asteraceae and Fabaceae (18.5%, for each) as well as Malvaceae (12.9%), were used as antiasthmatics and related symptoms by these THs. Most of the plants were trees and herbs (37.5%, for each), with root (57%), leaf (15.8%), and bark (7.5%), respectively, being the saliently used parts for preparation of remedies. Clerodendrum ternatum, Cryptocarya transvaalensis, Lasiosiphon caffer, Enicostema axillare, Mimusops obovata, Sclerocarya birrea, and Stylochaeton natalensis were widely used and valued by all THs across the surveyed districts. Furthermore, these taxa also scored both the highest use value and fidelity level indexes as asthma therapies. Overall, the larger number of species documented in the present study is recorded for the first time in literature as asthma and/or related symptoms remedies. Our study finding generally contributes towards an establishment of South African database of herbal therapies used traditionally against these conditions.

Experimental poisoning by Vernonia rubricaulis in sheep

In order to evaluate the susceptibility of sheep to V. rubricaulis and to establish the clinical signs, serum biochemistry, and pathological findings, eight sheep were fed varying doses of V. rubricaulis. The onset of clinical signs occurred 6-48 h after the ingestion of V. rubricaulis. Clinical courses lasted 6-56 h after the ingestion of the plant. Serum activities of aspartate aminotransferase, gamma-glutamyl transferase, and alkaline phosphatase were highly elevated and glucose blood levels were low in affected sheep. Clinical signs consisted of apathy, anorexia, dry muzzle, respiratory distress, abdominal pain, and mushy feces with streaks of blood and mucus. Two sheep had neurological signs including muscle fasciculation, nystagmus, paddling movements, and blindness. Liver necrosis could be detected antemortem through liver biopsy. Five sheep died and three recovered. The liver was affected in all necropsied sheep; it increased in volume and had marked accentuation of the lobular pattern with red, depressed areas intercalated with a pale yellow network. Ascites and hydropericardium were consistent findings. Microscopically, centrilobular to massive coagulative necrosis was observed. Coagulative necrosis was also observed in a few proximal renal tubules. Microscopic lesions were not found in any other organs. The severity of liver lesions was proportional to the dose. Chemical analysis to detect carboxyatractyloside in V. rubricaulis plant material was negative. It is concluded that V. rubricaulis poisoning in sheep is clinically, biochemically, and pathologically characteristic of an acute hepatoxicosis.

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.

Medicinal Plants Used by Traditional Healers in Sangurur, Elgeyo Marakwet County, Kenya

Background:

Although herbal medical products are still widely used in Kenya, many of the medicinal plants used by traditional medical practitioners (TMPs) have not been documented, despite several challenges that are now threatening the sustainability of the practice.

Objective:

To document the medicinal plants and healing methods used by TMPs in a region of Kenya with several recognized herbalists for potential research.

Materials and Methods:

Semi-structured interviews, group discussions, and direct observations were used to collect ethnopharmacological information. The participant's bio-data, clinical conditions treated, methods of treatment, medicinal plants used, methods of preparation and administration, and dosage forms were recorded.

Results:

A total of 99 medicinal plants and 12 complementary preparations employed in the treatment of 64 medical conditions were identified. The most widely used plant was Rotala tenella which was used to treat nine medicinal conditions; seven each for Aloe tweediae and Dovyalis abyssinica; and six each for Basella alba and Euclea divinorum. The plants belonged to 55 families with Fabaceae family being the most frequently used (10), followed by Apocynaceae and Solanaceae, each with six species, respectively. We identified plants used to determine the sex of an unborn baby and those used to treat several conditions including anthrax and cerebral malaria and herbs used to detoxify meat from an animal that has died from anthrax. Of special interest was R. tenella which is used to prevent muscle injury.

Conclusions:

We have documented several plants with potential therapeutic effects. Further research may be conducted to determine their efficacy.

SUMMARY

The medicinal plants used by traditional healers in a community which still practices herbal medicine in Kenya were documented. A total of 99 medicinal plants and 12 complementary preparations employed in the treatment of 64 medical conditions were identified. Further research may be carried out in order to determine their therapeutic efficacies.

Abbreviations Used: F_ic: Informant consensus factor, N_ur: Number of use reports in each category, N_s: Number of reported species, TMPs: Traditional medical practitioners.

Medicinal plants used in Lesotho for treatment of reproductive and post reproductive problems

ETHNOPHARMACOLOGICAL RELEVANCE

Reproductive healthcare has been highlighted as a major challenge in Lesotho mainly due to the high prevalence of HIV/AIDS and sexually transmitted infections. As a result other reproductive ailments have not received much attention, particularly because healthcare facilities are already limited and many of them are inaccessible. For these reasons, medicinal plants play a major role in primary healthcare system in the country, in addition the plants are easily accessible, more affordable, and their use forms part of the cultural heritage. However, documentation of medicinal plants used for reproductive ailments is scattered, more importantly the biological and pharmacological properties, as well as toxicity of many of these plants are not yet known.

AIM OF THE STUDY

To document the plants used by both male and female Basotho (residing in Lesotho) for the treatment of reproductive ailments, to explore their recorded biological and pharmacological effects as well as their toxicity, and to establish if these plants are used for similar purposes in other southern African cultures.

MATERIALS AND METHODS

The results stem from published findings of recent interviews of traditional medicinal practitioners in the Maseru District of Lesotho, first author's own experiences and observations from the Qacha's Nek District as well as comprehensive literature survey including numerous books and unpublished data. Electronic databases such as Google, Google Scholar, PubMed, and ScienceDirect were also used to search for the chemical compounds, pharmacological activity, and toxicity of the plants.

RESULTS

A total of 87 plant species are reported to be used for the treatment of several reproductive problems such as infertility, complications associated with pregnancy (twelve plants are used to treat conditions such as colic, heartburn, nausea, and constipation), cleansing and/ or toning of the uterus (with a purpose either to induce pregnancy or to get rid of the placenta, for example Withania somnifera and Zantedeschia albomaculata), difficult childbirth, as well treatment of breast and cervical cancer, cysts, fibroids, and testicular tumours (e.g. Hypoxis hemerocallidea). For the toning of the uterus, it is common to use a combination of plants, e.g. Gunnera perpensa, Scabiosa columbaria, and Eriospermum ornithogaloides.

CONCLUSIONS

Of the 87 plants used for reproductive healthcare, the highest number (31) is used for the treatment of infertility (in both men and women). The pharmacological effects, active compounds, and toxicology of many of these plants are not yet known.

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

ETHNOPHARMACOLOGICAL REFERENCE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Hepatoprotective effects of Flagellaria indica are mediated through the suppression of pro-inflammatory cytokines and oxidative stress markers in rats

Context The antioxidative properties of plants or plant derivative products are well known for their free radical scavenging effects. Flagellaria indica L. (Flagellariaceae) (FI) is a tropical medicinal plant used by the natives of Sabah as medication for semi-paralysis. Objective This study evaluates the hepatoprotective mechanism of FI against carbon tetrachloride (CCl4)-mediated liver damage. Materials and methods Aqueous extract of FI leaves was orally administered to adult Sprague-Dawley rats once daily for 14 consecutive days at 300, 400, and 500 mg/kg b.w. prior to CCl4 treatment (1.0 mL/kg b.w.) on the 13th and 14th days. Results Total phenolic content in the aqueous extract of FI leaves was 65.88 ± 1.84 mg gallic acid equivalent/g. IC50 value for free radical scavenging activity of FI aqueous extract was reached at the concentration of 400 μg/mL. Biochemical studies show that the aqueous extract of FI was able to prevent the increase in levels of serum transaminases, alanine aminotransferase, and aspartate aminotransferase (38-74% recovery), and malondialdehyde formation (25-87% recovery) in a dose-dependent manner. Immunohistochemical results evidenced the suppression of oxidative stress markers (4-hydroxynonenal and 8-hydroxydeoxyguanosine) and pro-inflammatory markers (tumour necrosis factor-α, interleukin-6, prostaglandin E2). Histopathological and hepatocyte ultrastructural alterations proved that there were protective effects in FI against CCl4-mediated liver injury. Signs of toxicity were not present in rats treated with FI alone (500 mg/kg b.w.). Discussion and conclusion It can be concluded that the presence of phenolic constituents and their antioxidative effects can be credited to the hepatoprotective activity of FI.

Poisoning of sheep by Vernonia plantaginoides (Less.) Hieron in Uruguay

Vernonia plantaginoides (Less.) Hieron, previously known as Vernonia squarrosa, is a rhizomatous subshrub with purple flowers that is prevalent in the natural grassland of Uruguay, Argentina, and southern Brazil. We report an outbreak of V. plantaginoides (yuyo moro) intoxication in sheep in Treinta y Tres Department, northeastern Uruguay. A total of 54 of 463 (12%) recently weaned lambs died 2-7 days after entering a natural pasture that had been invaded by sprouting V. plantaginoides The first cases were found dead. Affected lambs showed marked jaundice, edema of the face, ears, and eyelids, and severe photodermatitis. At the autopsies of 3 lambs, the carcass was yellow, the liver was enlarged with a marked acinar pattern ("nutmeg liver"), and hemorrhages were observed on serous membranes. Microscopic lesions were characterized by diffuse periacinar hepatocellular necrosis and cholemic nephrosis. Three female lambs were experimentally dosed with the aerial parts of V. plantaginoides collected immediately after the outbreak. The lamb that was dosed once with 40 g/kg body weight died after 36 h with severe hepatic necrosis. The lamb dosed with 20 g/kg daily for 4 days showed clinical signs and microscopic lesions in the liver with multiple apoptotic hepatocytes in the periacinar zone. The third lamb, dosed with 30, 17, and 15 g/kg daily over 3 days, respectively, showed transient clinical signs and a rise in liver enzymes, but recovered, and no lesions were found postmortem. These results demonstrate that V. plantaginoides was responsible for severe field outbreaks of poisoning in sheep in Uruguay.

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.

Ethnobotanical survey of medicinal plants used in the Maseru district of Lesotho

ETHNOPHARMACOLOGICAL RELEVANCE

Ethnobotanical knowledge in Lesotho is passed on orally from one generation to another. As a result it has not been well documented. Existing publications have relied on previous literature and are limited either in terms of scope or coverage. Furthermore, some of them are out of print. Therefore, there are gaps in the documentation of medicinal plants used in Lesotho.

AIM OF THE STUDY

The purpose of the current study is to investigate common ailments in Lesotho's traditional medicine and document plants that are used in treating such ailments.

MATERIALS AND METHODS

Interviews were conducted in five urban and four rural areas of the capital town of Maseru, by means of questionnaires to elicit information on medicinal plant use to cure common ailments. The informants were 20 males and seven females comprising 15 traditional healers, 11 herbalists and one pharmacist.

RESULTS

Reproductive ailments were found to be the most commonly treated, followed by respiratory, degenerative and digestive problems. A list of the 80 plants used for treating the common ailments is given. A total of 44 families is represented, with Asteraceae, Fabaceae, Asphodelaceae and Poaceae families having the highest number of species used for medicinal purposes. The most frequently mentioned medicinal plants in interviews include; Elephantorrhiza elephantina, Pentanisia prunelloides, Hypoxis hermerocallidea, Eriocephalus sp., Salvia runcinata, Scabiosa columbaria, Dicoma anomala, Morella serrata, Xysmalobium undulatum, and Leobordea lanceolata. Due to the high demand of medicinal plants, some species such as L. lanceolata, Tephrosia capensis, E. elephantina, D. anomala and P. prunelloides were reported as over-harvested. In some cases animal products are added to the medicinal plants to enhance their curative abilities.

CONCLUSIONS

A total of 80 plants were recorded in the study as treating 38 common ailments in the Maseru district of Lesotho. Records of eight medicinal plants and 146 new medicinal uses of 34 plants that were not recorded elsewhere in literature are reported in the current study for the first time. The new records of medicinal plants used in traditional healing practices in Lesotho clearly show the need to document these practices, and the wealth of new knowledge gained with the current study reinforces the importance of extending the study to other parts of Lesotho.

Adverse drug reactions in some African herbal medicine: literature review and stakeholders' interview

BACKGROUND

In view of the large consumption of herbal medicine in Africa countries, it is likely that many adverse drugs reactions go unrecorded with either patients failing to present to health services, or no pharmacovigilance analysis being made, or the analysis not being reported centrally. This problem is of interest especially for those who are working in the general area of adverse drug reactions or stakeholders in the domain of herbal medicine for considering safety issues.

METHODS

We are particularly interested in the way that the use of very well-known and highly valued plants is linked to the observation of adverse drug reactions in African countries. We investigated, through a literature review and using the Internet (with a semantic search strategy), some well-known or popular medicinal plants used in African herbal medicine (AHM). Other information on the properties related to use, and characteristics of medicinal plants was complemented by some interviews with stakeholders.

RESULTS

Although substantial progress has been made in elucidating the mechanisms of action of many drugs, the pharmacological actions of many medicinal plants are generally not well understood. The results of a literature review suggest that the reported adverse drug reactions of herbal remedies are often due to a lack of understanding of their preparation and appropriate use. The results of stakeholders' interviews suggest that there is a growing need to provide patients with correct information about the herbal medicines they consume.

CONCLUSION

An important aspect of herbal medicine is the correct, timely, and integrated communication of emerging data on risk as an essential part of pharmacovigilance, which could actually improve the health and safety of patients. This calls for improved collaboration between traditional practitioners and modern healthcare professionals, researchers, and drug regulatory authorities. In addition, there is a need for an adverse drug reaction reporting system to facilitate the collection, monitoring, and evaluation of adverse drug events.