Antimalarial activity in crude extracts of Malawian medicinal plants

Modulatory properties of Thespesia garckeana (F. Hoffm.) Exell & Hillc. Aqueous fruit extract on female rats reproductive hormones and tissues histology and potential inhibitory activity of its constituents against SRD5α2

ETHNOPHARMACOLOGICAL RELEVANCE

Thespesia garckeana (F. Hoffm.) Exell & Hillc. is called Gorontula (Kola of Tula) in Nigeria, Morojwa in Bostwana, and Thespesia garckeana in South Africa and is widely distributed across Africa. Its parts reportedly possess multiple medicinal properties and are employed for treating various diseases. In Tula, Gombe State, Nigeria, the ripe fruit decoction is taken as remedy for female infertility as documented by Ochokwu and co in the Journal of Biology, Agriculture and Healthcare in 2015.

AIM OF THE STUDY

This research examined the effects of aqueous fruit extract of T. garckeana (F. Hoffm.) Exell & Hillc. (AFETG) on selected reproductive tissues and hormones in female rats and also evaluated the inhibitory potentials of its phytoconstituents against human 5-alpha reductase 2 (SRD5α2) using in silico approach.

METHODS

Twenty-five (25) sexually matured female rats were randomized into 5 groups (i.e. A - E). Oestrous in the rats was synchronized (subcutaneous oestradiol conjugate [10 μg/100 g BW]). Group A received distilled water (control). Group B received standard drug, clomiphene citrate (0.85 mg/kg BW), while groups C, D, and E received AFETG at 50, 100, and 200 mg/kg BW respectively. The animals were treated for five (5) days and sacrificed 24 h after. Their blood was collected and prepared for analysis of serum prolactin, oestradiol (E2), follicle-stimulating hormone (FSH), and luteinizing hormone (LH) while ovaries, uteruses, and oviducts were studied for histological and histomorphometric changes. For the in silico study, the target protein, human steroid 5α-reductase 2 (SRD5α2) was prepared and its receptor grid was generated using Optimized Potential for Liquid Simulations-2005. The ligand 2D structures were prepared using LigPrep 2.4 software and docked using Glide. The binding energy of the ligands to the protein receptor was predicted using Molecular Mechanics/Generalized Born Surface Area (MM-GBSA) analysis.

RESULTS

AFETG significantly increased serum levels of E2 but did not alter serum levels of prolactin, LH and FSH when compared with distilled water and clomiphene citrate. AFETG also significantly increased ovarian tertiary follicular diameter, oviductal epithelial height and serosa thickness as well as uterine endometrial epithelial height, endometrial thickness, and myometrial thickness when compared with control. Ovarian secondary follicular diameter and oviductal submucosa thickness and muscular thickness were significantly decreased by AFETG when compared with control. Two compounds in T. garckeana (F. Hoffm.) Exell & Hillc.; D-Melezitose (-12.55 kcal/mol XP GScore) and 1, 3, 4-trihydroxy-5-oxo cyclohexane-1-carboxylic acid (-9.136 kcal/mol XP GScore) exhibited higher binding affinities for SRD5α2 than the reference ligand, epristeride (-8.096 kcal/mol XP GScore). In conclusion, the ability of AFETG to increase serum E2 level, thickness of uterine endometrium and ovarian tertiary follicles size can be explored for the treatment of female infertility caused by thinning of the uterine endometrium and reduced follicular size. Two compounds in AFETG (i.e. D-Melezitose and 1, 3, 4-trihydroxy-5-oxo cyclohexane-1-carboxylic acid are potential inhibitors of SRD5α2, thus aiding the biosynthesis of E2. Available evidence therefore corroborate the traditional use of T. garckeana (F. Hoffm.) Exell & Hillc fruit as a female fertility enhancer in Northern Nigeria.

Ethnobotanical Study of Traditional Medicinal Plants Used for the Treatment of Infectious Diseases by Local Communities in Traditional Authority (T/A) Mbelwa, Mzimba District, Northern Region, Malawi

Local communities in Mzimba District, Malawi, have limited access to healthcare services and often rely on traditional medical practice and medicinal plants (MPs) for most of their medical care. However, phytomedicines’ use has not been well documented. This study aimed to identify and document medicinal plants and the associated ethnobotanical knowledge. Ethnobotanical data were collected in seven localities (19 villages) in the T/A Mbelwa, Mzimba, from May to June 2021. Forty traditional healers, herbalists, and farmers selected purposively and by snowball sampling were interviewed through semi-structured interviews, field observations, group discussions, and guided field walks. Quantitative indices, viz. relative frequency of citation (RFC), use value (UV), relative importance (RI) values, informant consensus factors (ICFs), and fidelity levels (FLs), were used to analyze the data. Eighty MPs belonging to 43 families and 77 genera were recorded. The Leguminosae family showed the highest number of species (16), followed by Solanaceae, Rubiaceae, and Phyllanthaceae. Trees (35 species) and roots (62%) accounted for the most significant habit and part, respectively. Washing (29%) was the most common preparation method. The most cited plant was Zanthoxylum chalybeum (RFC = 0.80, UV = 0.28, RI = 1.66), followed by Cassia abbreviata (RFC = 0.68, UV = 0.35, RI = 1.50). Respiratory disorders showed the highest ICF (0.53), followed by general and unspecified disorders (0.31). Z. chalybeum, C. abbreviata, and Oldfieldia dactylophylla showed maximum FLs (100%) for treating malaria and dysentery. Phytochemical, bioassay, toxicity, and conservation studies are needed to assess medicinal plants’ safety, efficacy, and quality as steps toward discovering new promising therapeutic leads without neglecting conservation programs for their sustainable utilization.

Anti-plasmodial potential of selected medicinal plants and a compound Atropine isolated from Eucalyptus obliqua

The present research study was aimed to investigate the efficiency of selected medicinal plants against Plasmodium vivax. Crude methanolic extracts from the seeds of leaves of Datura stramonium, Parthenium hysterophorus, Calotropis procera, and Dodonaea viscosa were prepared. In addition, Atropine was also isolated from alkaloid components of Eucalyptus obliqua to evaluate their in vitro anti-plasmodial effects. It was observed that proguanil (positive control) and Atropine displayed strong anti-plasmodial activity (94.04 and 68.02%, respectively) against P. vivax at 0.1 mg/mL concentration while the leaf extracts of other medicinal plants did not exhibit any notable anti-plasmodial activity. It was concluded that alkaloids of E. obliqua plant’s extracts were rich in anti-plasmodial compound Atropine, which exhibit a remarkable anti-plasmodial activity against P. vivax. Anti-plasmodial action of medicinal plants are attributed to these phytochemicals. In vitro studies using medicinal plant’s extracts and standardized methods will help to make more powerful and cost-effective anti-plasmodial compounds.

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.

Potential of Malawi's medicinal plants in Covid-19 disease management: A review

The Coronavirus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has triggered an international pandemic that has led to significant public health problems. To date, limited evidence exists to suggest that drugs are effective against the disease. As possible treatments are being investigated, herbal medicines have shown potential for producing novel antiviral agents for the COVID-19 disease.

Aim

This review explored the potential of Malawi's traditional medicinal plants for the management of COVID-19.

Methods

The authors searched on PubMed and Google scholar for medicinal plants that are used in Malawi and published in openly available peer reviewed journals. Plants linked with antiviral treatment, anti-COVID-19 activity or COVID-19 symptoms management were targeted. These included activity against pneumonia, inflammation, cough, difficulty in breathing, pain/aches, fever, diarrhoea, rheumatism, fatigue, asthma, immunocompromised and cardiovascular diseases.

Results

11 studies were found with 306 plant species. 127 plant species had at least one COVID-19 related pharmacological activity. Of these plant species, the number of herbal entities used for each indication was: pain/aches (87), fever (2), pneumonia (9), breathing/asthma problems (5), coughing (11), diarrhoea (1), immunosuppression (8), blood issues (10), fatigue (2), heart problems (11), inflammation (8), rheumatism (10) and viral diseases (12). Thirty (30) species were used for more than one disease and Azedarachta indica topped the list (6 of the 13 COVID-19 related diseases). The majority of the species had phytochemicals known to have antiviral activity or mechanisms of actions linked to COVID-19 and consequent diseases' treatment pathways.

Conclusion

Medicinal plants are a promising source of compounds that can be used for drug development of COVID-19 related diseases. This review highlights potential targets for the World Health Organization and other research entities to explore in order to assist in controlling the pandemic.

Ethnobotanical study of plants used by the traditional healers to treat malaria in Mogovolas district, northern Mozambique

INTRODUCTION

Malaria is an important parasitic disease that affects mostly the African continent. Traditional medicine is very important in Mozambique and traditional healers play a key role in the primary health care services, particularly in rural areas. We aim to report the results of an ethnobotanical survey undertaken in Mogovolas district, northern region of Mozambique. We recorded and identified the medicinal plants used by traditional healers for treatment of malaria, as well as the mode of preparation and administration.

METHODS

The study was conducted in 14 villages from Mogovolas between June and August 2015. Sixteen traditional healers were interviewed using semi-structured questionnaires. Under their guidance, we collected medicinal plants and prepared herbarium specimens that were sent and kept at Eduardo Mondlane University Herbarium for scientific identification. We searched for information on the in vitro and in vivo studies of the cited plants for antiplasmodial activity.

RESULTS

Traditional healers from Mogovolas district reported the use of 37 plants to treat malaria, belonging to 22 families. The most used species are Ochna kirkii Oliv. (5 citations), Ehretia amoena Klotzsch and Pteleopsis myrtifolia (M.A.Lawson) Engl. & Diels (both with 3 citations). These plants belong to Ochnaceae, Boraginaceae and Combretaceae families, respectively. The herbal remedies are prepared using leaves (22/37), roots (18/37), stem barks (16/37) and stems (3/37). The administration of the herbal remedies was made essentially by oral route and bathing.

CONCLUSION

The ethnobotanical data resulted from this study can be the starting point for further chemical and pharmacological studies aiming to identify medicinal species with antimalarial activity, thus, open the insights for the discovery of new antimalarial substances, as well as better integration of the traditional medicine into the national health systems, particularly in developing countries, as the health system coverage is limited.

Traditional uses of medicinal plants against malarial disease by the tribal communities of Lesser Himalayas-Pakistan

ETHNOPHARMACOLOGICAL RELEVANCE

Malaria is among the most prevalent infectious diseases in the developing countries of world. Estimated number of annual malaria episodes in Pakistan is 1.5 million, but very little is known about medicinal plant species of Pakistan, which have great potential against malarial disease. Present study was aimed to document medicinal plant species used by the local inhabitants of Lesser Himalayas-Pakistan to treat malaria.

MATERIALS AND METHODS

Data were collected through interviews, questionnaires and contributor observation. A total of 55 informants aged between 25 and 80 years who were familiar with malarial disease participated in the survey.

RESULTS

A total of 84 plant species belonging to 69 genera and 50 families were recorded to treat malaria. Asteraceae was found as most cited botanical family with (11.9%) representation, followed by Lamiaceae (5.9%), Solanaceae and Verbenaceae (4.7%) and Violaceae (3.5%) respectively. About 60% of the inhabitants prefer herbal treatment by local herbalists or self-treatment with locally available medicinal plant species. Of the plants identified during present investigation against malaria, Azadirachta indica, Swertia chirayita and Swertia ciliata exhibited uppermost frequency of encounter (36.3%) and corresponding PR value 5. About 67.2% of the botanical taxa are reported for the first time in the treatment of malaria. It was observed thatover harvesting is the foremost threat to medicinal plant species of the study area.

CONCLUSION

Present survey indicates that traditional knowledge about the use of plant species against various diseases and particularly to treat malaria is in decline. Similarly anthropogenic pressure, over exploitation and grazing of the botanical taxa are the major concerns regarding medicinal plant biodiversity loss. Frequently utilized plant species with significant malarial reduction should be authenticated by in vitro and in vivo standard tests.

The globalization of traditional medicine in northern peru: from shamanism to molecules

Northern Peru represents the center of the Andean "health axis," with roots going back to traditional practices of Cupisnique culture (1000 BC). For more than a decade of research, semistructured interviews were conducted with healers, collectors, and sellers of medicinal plants. In addition, bioassays were carried out to evaluate the efficacy and toxicity of plants found. Most of the 510 species encountered were native to Peru (83%). Fifty percent of the plants used in colonial times have disappeared from the pharmacopoeia. Market vendors specialized either on common and exotic plants, plants for common ailments, and plants only used by healers or on plants with magical purposes. Over 974 preparations with up to 29 different ingredients were used to treat 164 health conditions. Almost 65% of the medicinal plants were applied in these mixtures. Antibacterial activity was confirmed in most plants used for infections. Twenty-four percent of the aqueous extracts and 76% of the ethanolic extracts showed toxicity. Traditional preparation methods take this into account when choosing the appropriate solvent for the preparation of a remedy. The increasing demand for medicinal species did not increase the cultivation of medicinal plants. Most species are wild collected, causing doubts about the sustainability of trade.

Traditional use of medicinal plants in south-central Zimbabwe: review and perspectives

BACKGROUND

Traditional medicine has remained as the most affordable and easily accessible source of treatment in the primary healthcare system of resource poor communities in Zimbabwe. The local people have a long history of traditional plant usage for medicinal purposes. Despite the increasing acceptance of traditional medicine in Zimbabwe, this rich indigenous knowledge is not adequately documented. Documentation of plants used as traditional medicines is needed so that the knowledge can be preserved and the utilized plants conserved and used sustainably. The primary objective of this paper is to summarize information on traditional uses of medicinal plants in south-central Zimbabwe, identifying research gaps and suggesting perspectives for future research.

METHODS

This study is based on a review of the literature published in scientific journals, books, reports from national, regional and international organizations, theses, conference papers and other grey materials.

RESULTS

A total of 93 medicinal plant species representing 41 families and 77 genera are used in south-central Zimbabwe. These plant species are used to treat 18 diseases and disorder categories, with the highest number of species used for gastro-intestinal disorders, followed by sexually transmitted infections, cold, cough and sore throat and gynaecological problems. Shrubs and trees (38% each) were the primary sources of medicinal plants, followed by herbs (21%) and climbers (3%). The therapeutic claims made on medicinal plants documented in south-central Zimbabwe are well supported by literature, with 82.8% of the plant species having similar applications in other regions of Zimbabwe as well as other parts of the world and 89.2% having documented biological and pharmacological properties.

CONCLUSION

This study illustrates the importance of traditional medicines in the treatment and management of human diseases and ailments in south-central Zimbabwe. Traditional medicines still play an important role in meeting basic health care of local communities in Zimbabwe.

Screening of traditionally used plants for in vivo antimalarial activity in mice

Aqueous ethanol (80%) extracts of six plants used traditionally for treatment of malaria, Vepris glomerata (F.Hoffm.) Engl (Rutaceae), Maranthus floribunda (Bak.) F.White (Chrysobalanaceae), Strophanthus eminii Asch. & Pax ex Pax (Apocynaceae), Cassia abbreviata Oliv. (Leguminosae) and Caesalpinia bonducella L. Fleming (Fabaceae) were screened for antimalarial activity to establish validity of their claims. The extracts exhibited antimalarial activity in the 4-day Peter's suppressive antimalarial assay in mice inoculated with red blood cells parasitized with Plasmodium berghei. The extracts gave ID(50) values of 42.8, 111.0, 639.3 and 1560 mg/kg body wt for C. bonducella, C. abbreviata, T. furialis and S. eminii, respectively. The ID(50) values for V. glomerata and M. floribunda were above 2400 mg/kg body wt, above which point solubility was a problem. All the tested extracts were innocuous to the mice, up to 2400 mg/kg body wt, suggesting they may be safe for short-term use.

Traditional antimalarial phytotherapy remedies used by the Kwale community of the Kenyan Coast

In Kenya, most people especially in rural areas use traditional medicine and medicinal plants to treat many diseases including malaria. Malaria is of national concern in Kenya, in view of development of resistant strains of Plasmodium falciparum to drugs especially chloroquine, which had been effective and affordable. There is need for alternative and affordable therapy. Many antimalarial drugs have been derived from medicinal plants and this is evident from the reported antiplasmodial activity. The aim of the study was to document medicinal plants traditionally used to treat malaria by the Digo community of Kwale district. Traditional health practitioners were interviewed with standardized questionnaires in order to obtain information on medicinal plants traditionally used for management of malaria. Twenty-five species in 21 genera and 16 families were encountered during the study. Celestraceae, Leguminosae and Rubiaceae families represented the species most commonly cited. Three plant species, namely; Maytenus putterlickioides, Warburgia stuhlmannii and Pentas bussei are documented for the first time for the treatment of malaria.

Diversity and utilization of antimalarial ethnophytotherapeutic remedies among the Kikuyus (Central Kenya)

Plants in Kenya are becoming increasingly important as sources of traditional medicines. The World Health Organization (WHO) has estimated that malaria kills about 2.7 million people every year, 90% of who are from Africa. Malaria continues to be a national concern in Kenya as it plays a major role in the high mortality rates being experienced currently. The use and mis-use of chloroquine to prevent and treat falciparium malaria has led to widespread appearance of chloroquine resistant parasites in Kenya and other tropical countries. These factors and the rising costs of non-chloroquine drugs have made the local people to turn to traditional remedies for management of this menace. This paper examines the current utilization of traditional plant medicines in managing malaria menace in Central Kenya. The results show both indigenous and introduced species are in use indicating traditional medicinal practices in this region are dynamic. In total 58 species in 54 genera and 33 families were identified. The family Rubiaceae was found to have the highest number of reported species. Use of the various taxa is compared between five districts within Central Province of Kenya. The commonest species in this pharmacopoeia are: Caesalpinia volkensii Harms, Strychnos henningsii Gilg, Ajuga remota Benth., Warbugia ugandensis Sprague and Olea europaea L. The first three species are used in all the five districts while the others are restricted in some of the districts. In 74% of the anti-malarial plant species reported in this study, the remedies are obtained in destructive manner and may need conservation measures to ensure sustainable utilization. The results of this study become a basis for selecting plants for further pharmacological and phytochemical studies in developing new and locally relevant anti-malarial agents.

Sub-acute intoxication by Senna occidentalis seeds in rats

Senna occidentalis (So) is a weed that grows in pastures along fences and in fields cultivated with cereals such as corn and soybean, and many reports have been showing intoxication with this plant in different animal species. It is also used in many medicinal purposes. The objective of the present study was to better evaluate the toxic effects of prolonged administration of So seeds to rats. Forty male Wistar rats were divided into four groups of 10 animals each, three of them respectively fed rations containing 1%, 2% and 4% So seeds, and the last one (control) fed commercial ration for a period of 2 weeks. Fourteen rats were also used in a pair-feeding (PF) experiment. The rats of the experimental groups showed lethargy, weakness, recumbency, depression and emaciation. Two rats of the 4% group and two of the PF group died during the experiment. Histopathological study showed fiber degenerations in the skeletal (Tibial, pectoral and diaphragm) and cardiac muscles. In the liver parenchyma, was observed vacuolar degeneration and, in the kidney, mild nefrosis in the proximal convoluted tubules. All of these alterations occurred in a dose-dependent fashion. Moderate to severe degeneration and spongiosis in the central nervous system, especially in cerebellum. Electron microscopy revealed mitochondrial lesions in all analyzed tissues.

Antimalarial activity of extracts of Malaysian medicinal plants

In vitro and in vivo studies revealed that Malaysian medicinal plants, Piper sarmentosum, Andrographis paniculata and Tinospora crispa produced considerable antimalarial effects. Chloroform extract in vitro did show better effect than the methanol extract. The chloroform extract showed complete parasite growth inhibition as low as 0.05 mg/ml drug dose within 24 h incubation period (Andrographis paniculata) as compared to methanol extract of drug dose of 2.5 mg/ml but under incubation time of 48 h of the same plant spesies. In vivo activity of Andrographis paniculata also demonstrated higher antimalarial effect than other two plant species.