Ethnobotanical study of antimalarial plants in Shinile District, Somali Region, Ethiopia, and in vivo evaluation of selected ones against Plasmodium berghei

Efficacy of Albizia malacophylla (A.Rich.) Walp. (Leguminosae) methanol (80%) leaf extract and solvent fractions against Plasmodium berghei-induced malaria in mice model

ETHNOPHARMACOLOGICAL RELEVANCE

Novel drugs are needed to address the issue of malarial infection resistance; natural items can be a different source of these medications. Albizia malacophylla (A. Rich.) Walp. (Leguminosae) is listed as one of the antimalarial medicinal plants in Ethiopian folk medicine. However, there are no reports regarding the biological activity or phytochemistry of the plant.

AIM OF THE STUDY

Thus, this study aimed to evaluate the A. malacophylla crude extract and solvent fractions' in vivo antimalarial activity utilizing 4-day suppressive, preventative, and curative tests in mice infected with P. berghei.

MATERIALS AND METHODS

The parasite Plasmodium berghei, which causes rodent malaria, was used to infect healthy male Swiss Albino mice, weighing 23-28 g and aged 6-8 weeks. Solvent fractions such as methanol, water, and chloroform were given in addition to an 80% methanolic extract at 100, 200, and 400 mg/kg doses. A Conventional test such as parasitemia, survival time, body weight, temperature, and packed cell capacity were employed to ascertain factors such as the suppressive, curative, and preventive tests.

RESULTS

Every test substance dramatically reduced the number of parasites in every experiment. Crude extract (with the highest percentage suppression of 67.78%) performs better antimalarial effect than the methanol fraction, which is the most efficient solvent fraction with a percentage suppression of 55.74%. With a suppression value of 64.83% parasitemia level, the therapeutic effects of 80% methanolic crude extract were greater than its curative and preventative effects in a four-day suppressive test. The survival period (17 days) was longer with the hydroalcoholic crude extract dose of 400 mg/kg than with other doses of the materials under investigation.

CONCLUSIONS

The results of this investigation validate the antimalarial characteristics of A. malacophylla leaf extract. The crude extract prevented weight loss, a decline in temperature, and a reduction in PCV. The results demonstrate that the plant has a promising antimalarial effect against P. berghei, hence supporting the traditional use of the plant. Therefore, it could serve as a foundation for the development of new antimalarial drugs.

The ethnopharmacological study of plant drugs used traditionally in Djibouti for malaria treatment

ETHNOPHARMACOLOGICAL RELEVANCE

Djibouti was a country where malaria has been endemic for centuries. The local population use the plants as repellents or first aid for uncomplicated malaria.

AIM OF THE STUDY

The aim was, for the first time, to collect and identify plants used by the local population to treat malaria and select the most interesting plants (those that are more commontly used, more available, and have fewer studies). These plants were evaluated for their antiplasmodial activity as well as their cytotoxicity on human cell lines for the most active ones.

MATERIALS AND METHODS

A semi-structured questionnaire was developed for this study to collect information about the use and identity of botanical drugs used to treat malaria. The use-reports (percentage) of each plant were recorded to determine their use importance. Also, the availability status of the plants was assessed; and those in critical condition were discarded excluded from further study. Fifteen plants, out of the 41 listed, were extracted with hydro alcohol, ethyl acetate, and dichloromethane for biological testing. Chloroquine-resistant strain FcB-1 of P. falciparum and a human diploid embryonic lung cell line were used for the antiplasmodial test, and to assess the cytotoxicity for human cells respectively. Preliminary analysis of extract constituents was carried out using thin layer chromatography (TLC).

RESULTS

This study identifies 41 plant taxa belonging to 32 families and records their use against malaria. Balanites rodunfolia, belonging to the Zygophyllaceae family, was the most commonly used plant, representing 44 % of use-reports. It was followed by Cadaba rodunfolia (15 %) from the Capparaceae family, and then the three species of Aloe: Aloe djiboutiensis (8.2 %), Aloe ericahenriettae (3.4 %), and Aloe rigens (3.4 %) from the Asphodelaceae family. The leaves are the most commonly used part of the plants to treat malaria, accounting for 76 % of usage. The preparation methods were decoction (52 %), maceration (29 %), and boiling (19 %). The administration routes were by oral (80 %), inhalation 19 %), and bathing (1 %). The best antiplasmodial activities were observed in the dichloromethane extracts of Cymbopogon commutatus and the ethyl acetate extracts of Aloe rigens and Terminalia brownii, with IC50 values of 9.8, 5, and 7.5 μg/mL, respectively. Their toxicity/activity levels were very favorable with selectivity indices of 5.6, 8.1, and 11.8 for C. commutatus, A. rigens, and T. Brownii, respectively.

CONCLUSION

Forty-one species of botanical drugs were listed as being used to treat malaria in Djibouti. All fifteen selected species showed antiplasmodial activity (IC50 < 50 μg/mL). This work will help guide the valorization of botanical drugs used to treat malaria in Djibouti.

Evaluation of packaging, labels, and some physicochemical properties of herbal antimalarial products on the Ghanaian market

Introduction

Malaria is a parasitic disease that is endemic in tropical areas and can be life-threatening. There has been a decrease in the prevalence of malaria in Ghana but the burden of the disease is still high in the country. Many Ghanaians depend on herbal products for malaria treatment. This study aimed to survey and evaluate commercial herbal antimalarials in the Volta Region of Ghana.

Methods

A survey of finished herbal antimalarials was done at herbal shops, pharmacies, and over-the-counter medicine seller shops. Products available on shelves were purchased and their details were recorded, after which they were examined using a visual inspection tool. The density, pH, and extract weight per dose of each sample were also determined.

Results

Thirty-four liquid formulations (A-1-34) containing 1-9 different herbs were found. The majority of the product labels had errors in consumer age classifications. Unconventional ways of stating doses were found on two products (A-13, "tot"; A-19, cupful). Six products did not have dosing devices. No duration of treatment was indicated on 24 products. Dose errors were found on A-14 and A-22. Samples A-17 and A-28 did not have registration or batch numbers. Product A-28 did not have its herbs listed on it and was indicated for persons aged 3-8 years at a dose of 45 mL. The relative density range for the products was 0.997-1.015. From the pH investigation, no product was extremely erosive; however, 10 samples were deemed erosive (pH, 3.0-3.99), whereas 24 were minimally erosive (pH, ≥4.0). The extract weight per dose volume (20-90 mL) was 0.048-1.766 g, indicating that unit dose capsules or tablets could be formulated from the products.

Conclusion

The findings clearly show that Ghanaian authorities responsible for regulating herbal products must enforce guidelines for the formulation, label details, and sale of antimalarial products. Additionally, the unpleasant taste of liquid herbal mixtures can affect patient compliance and dosing convenience; therefore, it is recommended that oral solid dosage forms of herbal antimalarials are produced as alternatives to the liquid mixtures.

Traditional Somali Diaspora Medical Practices in the USA: A Scoping Review

Minnesota has the largest Somali diaspora in the world. Uniquely, the Minnesotan Somali diaspora utilizes traditional healing practices along with Western medicine. Therefore, medical providers who regularly interact with Somali patients must be aware of traditional healing practices. A scoping review inclusive of three databases (Embase Classic + Embase, Ovid MEDLINE, PsychINFO) was conducted. Fifty-eight studies met established criteria. Traditional medicine is performed with conventional medicine. Illnesses are acknowledged to be caused by a malfunctioning body, evil eye, and/or zar (possession). Examples of the utilization of dawo dhaqmeed (traditional practices) included ilko dacowo (dental enucleation), khat (catha edulis), guboow (use of a fire-heated object), cupping, xoq (scraping), xidhayn (female genital mutilation), duugto (massage), baan (nutrition), herbs, caano geel (camel milk), Qur'anic healing, prayer, zam zam (holy water), tahliil liquid (blessed water), and amulets. Practices ranged from benign to harmful. Identifying Somali traditional healing practices is the first step in understanding the health of the Somali community in Minnesota.

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.

Antimalarial activity of the hydroalcoholic crude extract and solvent fractions of Commelina latifolia Hochst. ex C.B.Clarke (Commelinaceae) leaves against Plasmodium berghei in mice

Ethnopharmacological relevance

In Ethiopia, the indigenous medicinal plant Commelina latifolia Hochst. ex C.B. Clarke leaves are used to treat malaria and wounds.

Aim of the study

In this work, the antiplasmodial activity of Commelina latifolia crude leaf extract and solvent fractions against Plasmodium berghei-infected mice was investigated.

Materials and methods

80% methanol was used to extract the leaves of C. latifolia, and the crude extract was fractionated using chloroform, pure methanol, and distilled water. All test compounds were undergone an acute oral toxicity test before being put through Peter's 4-day suppressive test to see if they have antiplasmodial activity. The hydroalcoholic crude extract and chloroform fraction were additionally assessed for antimalarial activity using curative and prophylactic tests in P. berghei-infected laboratory mice.

Results

All of the tested crude extracts were safe at a dose of 2000 mg/kg. At 400 mg/kg dose both the 80% methanol extract and chloroform fraction exhibited antimalarial activity with parasitemia suppression values of 86.31%, and 76.56% in the four-day suppressive test, 81.97% and 72.05% in Rane's test, and 69.05% and 62.88% in the prophylactic test, respectively.

Conclusion

Collectively, the oral dose of Commelina latifolia is safe, and reveals promising antimalarial activity. The findings backed up the utilization of the plant in traditional medicine to treat malaria.

Phytochemical screening, cytotoxicity assessment and evaluation of in vitro antiplasmodial and in vivo antimalarial activities of Mentha spicata L. methanolic leaf extract

ETHNOPHARMACOLOGICAL RELEVANCE

Malaria causes extensive morbidity and mortality, and the decreasing efficacy of artemisinin and its partner drugs has posed a serious concern. Therefore, it is important to identify new antimalarials, and the natural compounds from plants provide a promising platform. Mentha spicata L. representing the Lamiaceae family has been used in traditional medicine for various diseases including malaria.

AIM OF THE STUDY

This study was aimed at evaluating the antiplasmodial activity of M. spicata methanolic leaf extract using Plasmodium falciparum (Pf) cultures (Pf3D7 and artemisinin (ART)-resistant PfCam3.I^R539T strains) and antimalarial activity using Plasmodium berghei (Pb)-infected mice. Dry leaf powder and methanolic leaf extract were examined for in vivo antimalarial activity and the efficacy of oral versus parenteral administration was compared.

MATERIALS AND METHODS

Leaves of M. spicata were collected and extracted using 70% methanol in water (v/v). [³H]-hypoxanthine incorporation assays and Giemsa-stained smears were used to assess the in vitro antiplasmodial activity of M. spicata methanolic extract against Pf3D7 and ART-resistant PfCam3.I^R539T strains. Cytotoxicity was evaluated in HeLa and HEK-293T cell lines using MTT assays. Hemolysis assays were performed using red blood cells (RBCs). In vivo antimalarial activities of M. spicata dry leaf powder and methanolic leaf extract were examined in P. berghei-infected mice by Rane's curative test and Peters' 4-day suppressive test.

RESULTS

Phytochemical screening of M. spicata methanolic leaf extract indicated the presence of reducing sugars, phenolic compounds, flavonoids, glycosides, sterols, saponins, alkaloids, coumarins, tannins, carbohydrates, and proteins. In vitro studies carried out using Pf cultures showed that M. spicata methanolic leaf extract had significant antiplasmodial activity against Pf3D7 cultures with a 50% inhibitory concentration (IC₅₀) of 57.99 ± 2.82 μg/ml. The extract was also effective against ART-resistant PfCam3.I^R539T strain with an IC₅₀ of 71.23 ± 3.85 μg/ml. The extract did not show significant in vitro cytotoxicity, hemolysis, and in vivo toxicity. In vivo studies performed using Pb-infected mice treated with M. spicata dry leaf powder and methanolic leaf extract showed ∼50% inhibition in parasite growth at 1500 mg/kg and 1000 mg/kg doses, respectively. There was also a significant delay in the mortality of treated mice. Parenteral administration was found to be appropriate for the in vivo treatment.

CONCLUSIONS

Our in vitro and in vivo findings from Pf and Pb parasites suggested the therapeutic potential of M. spicata leaf extract as an antimalarial. M. spicata leaf extract could also inhibit the growth of ART-resistant Pf strain. Further studies on fractionation and active component analysis of M. spicata leaf extract would be required to identify the bioactive phytochemicals having pharmaceutical and therapeutic values. Such efforts would help us in developing new antimalarials to combat malaria.

Medicinal plants used in traditional treatment of malaria in Ethiopia: a review of ethnomedicine, anti-malarial and toxicity studies

Background

Malaria is extremely common in Ethiopia, and it is one of the country's most serious public health and economic problems. Traditional medicines have long been utilized in Ethiopia by people of various ethnic groups. As a result, the goal of this study is to record the use of Ethiopian medicinal herbs that have been used to treat malaria. Also, a critical review of the literature on the therapeutic properties of these and other Ethiopian medicinal plants that have been tested against Plasmodium spp. parasites was conducted with the goal of highlighting neglected studies and fostering further research in this area.

Methods

A comprehensive literature search was performed in Scopus, Web of Science Core Collection, PubMed, Science Direct, Google Scholar, and Scientific Electronic Library Online (SciELO) from August 2021 to October 2021. The study databases included original articles published in peer reviewed journals covering anti-malarial plants, dated until October 2021.

Results

The review looked at 51 plant species (28 families) that have been used to treat malaria in Ethiopia. The most often used ethnobotanical plant species for the treatment of malaria were Allium sativum, Croton macrostachyus, Carica papaya, and Lepidium sativum. Leaves were used more frequently as a therapeutic preparation than other parts. Plant extracts were found to have very good, good, and moderate anti-malarial activity in mice with rodent Plasmodium species. The most active species were Ajuga remota and Capsicum frufescens, which suppressed parasitaemia by 77.34% and 72.65%, respectively, at an oral dose of 100 mg/kg and an LD50 of above 2000 mg/kg. The compound Aloinoside reported from Aloe macrocarpa leave latex was the most potent; it suppressed parasitaemia by 100% at 400 mg/kg oral dose of Plasmodium berghei infected mice, and its LD50 was above 2000 mg/kg. Toxicity was shown to be safe in 84% of the plant extracts.

Conclusion

In Ethiopia, medicinal plants have a significant part in reducing the severity of malaria due to their widespread use. As a result, more studies are needed to identify and develop effective novel drugs that could be employed in broader malaria eradication efforts.

Ethnobotanical importance, phytochemical constituents, and pharmacological properties of Withania somnifera

Withania somnifera belongs to the family of Solanaceae. It is widely used by the locals, especially in India, as a medicinal plant. W. somnifera is rich in alkaloid and steroidal lactone that account for various pharmacological activities. The present study aimed to review all the evidence on the ethnobotanical perspective of W. somnifera in some countries. This review also analyses the bioactive compounds that account for the pharmacological activities. The online medical literature databases such as ScienceDirect, PubMed, and Google Scholar were used to search articles up to March 2022. W. somnifera is widely used in Asian and African countries like India and South Africa, Pakistan, Egypt, Jordan, and Lesotho. In India, W. somnifera is prepared by boiling and crushing the leaves and roots to make a tonic poultice, juice, and paste to treat bacterial infections and bruises. Numerous in vivo and in vitro studies have demonstrated that W. somnifera exerts pharmacological effects such as anti-Parkinson’s, anti-Alzheimer’s, cardioprotective, antidiabetic, antiarthritic, and antibacterial properties. Withaferin A and withanolide are the major bioactive compounds contributing to the pharmacological effects. W. somnifera is a valuable plant that has been used in traditional medicine systems for a long time and is supported by its wide range of pharmacological activities. The extensive medicinal uses of W. somnifera are a sign of its great potential.

Nephroprotective Effect of Asparagus africanus Lam. Root Extract against Gentamicin-Induced Nephrotoxicity in Swiss Albino Mice

The kidney is the organ most vulnerable to nephrotoxic drugs such as gentamicin. Nephrotoxicity is a rapid deterioration of kidney function due to various factors. Gentamicin causes nephrotoxicity, which was manifested by an increase in serum kidney biomarkers. Asparagus africanus is one of the ethnomedicinal plants used as traditional medicine for treating various ailments, including kidney disease in Ethiopian society. Thus, the aim of this study is to evaluate the nephroprotective effect of A. africanus root extract on gentamicin-induced nephrotoxicity. Using maceration techniques, 100 g of dried plant powder was extracted in 1 L of ethanol. The physicochemical screening of plant extracts revealed the presence of flavonoids, phenols, tannins, saponins, and steroids. The nephroprotective activity of A. africanus crude extract was evaluated on male Swiss albino mice. The crude ethanolic extract at 200 and 400 mg/kg doses showed strong nephroprotective effects by restoring biomarkers such as creatinine, uric acid, and blood urea nitrogen, which were damaged by gentamicin (p < 0.05) in a dose-dependent manner. The mice treated with higher doses (400 mg/kg) had a comparable nephroprotective effect compared to the positive control group (200 mg/kg silymarin; p > 0.05). The histopathology of the control group showed normal glomeruli, normal parenchyma, distal convoluted, and no tubular damage. The toxicant-induced group showed damage to glomeruli and inflammatory infiltration. Therefore, A. africanus root extract has a nephroprotective activity by retarding the gentamicin toxicity in male Swiss albino mice.

Identification of lobetyolin as a major antimalarial constituent of the roots of Lobelia giberroa Hemsl

Lobelia giberroa Hemsl. is an endogenous Ethiopian medicinal plant with a long history of use in the treatment of malaria, bacterial and fungal diseases, and cancer. Here, we present the in vivo bioassay-guided fractionation of the 80% methanol extract of L. giberroa roots, which led to the isolation of lobetyolin. L. giberroa roots were extracted with 80% methanol, and the dried 80% methanol extract was fractionated with hexane, ethyl acetate, methanol, and water. Acute oral toxicity study was conducted according to the Organisation for Economic Co-operation and Development Guideline 425 by using female Swiss albino mice. Antimalarial activity was assessed in Plasmodium berghei-infected Swiss albino mice. Through in vivo bioassay-guided fractionation processes lobetyolin, a C14-polyacetylene glucoside, was isolated from the methanol fraction by silica gel column chromatography as the main active ingredient from the plant. The chemical structure of lobetyolin was elucidated by interpretation of spectroscopic data (¹HNMR, ¹³CNMR, IR. MS) including two dimensional NMR. The plant extract was considered safe for administration up to 2000 mg/kg. In the four-day suppressive test, the 80% methanol extract (400 mg/kg), methanol fraction (400 mg/kg), and lobetyolin (100 mg/kg) exhibited antimalarial activity, with chemosuppression values of 73.05, 64.37, and 68.21%, respectively. Compared to the negative control, which had a mean survival time of 7 days, the lobetyolin (100 mg/kg) and methanol fraction (400 mg/kg) treated groups had mean survival times of 18 and 19 days, respectively. The current study supports the traditional use of the plant for the treatment of malaria. The structural differences between lobetyolin and existing antimalarials, as well as its previously unknown antimalarial activity, make it of interest as an early lead compound for further chemical optimization.

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Multi-drug resistant malaria parasites urge the discovery of newer drugs.

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Lobelia giberroa is an indigenous traditional antimalarial plant of Ethiopia.

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In vivo antimalarial-activity-guided fractionation led to the isolation of lobetyolin.

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Lobetyolin exhibits a promising antimalarial activity with an ED₅₀ of 36.8 mg/kg.

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Lobetyolin is a potential lead compound to develop a new class of antimalarial drugs.

In vivo antiplasmodial activity of hydromethanolic leaf extract and solvent fractions of Maytenus gracilipes (Celastraceae) against Plasmodium berghei in mice

BACKGROUND

The incidence of resistance among currently available antimalarial drugs, as well as the high economic cost of malaria, has prompted researchers to look for novel antimalarial molecules. As a result, the current study was proposed to evaluate the antiplasmodial activity (in vivo) of Maytenus gracilipes based on the plant's traditional claims.

METHODS

A cold maceration procedure using 80% methanol as a solvent was employed to obtain a crude extract from M. gracilipes leaves. Chloroform, n-butanol, and pure water were used to fractionate the hydromethanolic extract. Standard procedures were followed for an acute oral toxicity test. The antimalarial effects of the plant at 200, 400, and 600 mg/kg doses were investigated using three rodent malaria models (4-day suppressive, rane's, and repository tests). Thirty mice were utilized in each experiment (3 treatment and 2 control groups, each with six mice). Parasitemia, survival time, body weight, temperature, and packed cell volume were all used to assess the extracts' antiplasmodial activity. To compare results between groups, a one-way ANOVA with Post Hoc Tukey's HSD was used.

RESULTS

In a 4-day suppressive investigation, all doses of the crude extract and fractions suppressed parasitemia significantly (P < 0.001) as compared to the negative control. The crude extract had the greatest chemosuppressive effect (74.15%) at 600 mg/kg dose. Chloroform had the greatest parasitemia suppression among the fractions; however it was less than the crude extract. In Rane's test, all doses of the crude extract produced substantial (P < 0.001) curative effects as compared to the negative control.

CONCLUSION

According to this study, the crude extract and solvent fractions of M. gracilipes leaves contain antimalarial activity with a substantial suppressive effect. The antiplasmodial effects were more active in the chloroform and n-butanol fractions, indicating that the plant's non-polar and medium polar constituents are responsible. Nonetheless, further analysis is required to isolate and characterize the active compounds responsible for the study plant's antimalarial activity.

Studies on Activities and Chemical Characterization of Medicinal Plants in Search for New Antimalarials: A Ten Year Review on Ethnopharmacology

Malaria is an endemic disease that affected 229 million people and caused 409 thousand deaths, in 2019. Disease control is based on early diagnosis and specific treatment with antimalarial drugs since no effective vaccines are commercially available to prevent the disease. Drug chemotherapy has a strong historical link to the use of traditional plant infusions and other natural products in various cultures. The research based on such knowledge has yielded two drugs in medicine: the alkaloid quinine from Cinchona species, native in the Amazon highland rain forest in South America, and artemisinin from Artemisia annua, a species from the millenary Chinese medicine. The artemisinin-based combination therapies (ACTs), proven to be highly effective against malaria parasites, and considered as “the last bullet to fight drug-resistant malaria parasites,” have limited use now due to the emergence of multidrug resistance. In addition, the limited number of therapeutic options makes urgent the development of new antimalarial drugs. This review focuses on the antimalarial activities of 90 plant species obtained from a search using Pubmed database with keywords “antimalarials,” “plants” and “natural products.” We selected only papers published in the last 10 years (2011–2020), with a further analysis of those which were tested experimentally in malaria infected mice. Most plant species studied were from the African continent, followed by Asia and South America; their antimalarial activities were evaluated against asexual blood parasites, and only one species was evaluated for transmission blocking activity. Only a few compounds isolated from these plants were active and had their mechanisms of action delineated, thereby limiting the contribution of these medicinal plants as sources of novel antimalarial pharmacophores, which are highly necessary for the development of effective drugs. Nevertheless, the search for bioactive compounds remains as a promising strategy for the development of new antimalarials and the validation of traditional treatments against malaria. One species native in South America, Ampelozyzyphus amazonicus, and is largely used against human malaria in Brazil has a prophylactic effect, interfering with the viability of sporozoites in in vitro and in vivo experiments.

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.

Evaluation of Antiplasmodial Activity of Hydroalcoholic Crude Extract and Solvent Fractions of Zehneria scabra Roots Against Plasmodium berghei in Swiss Albino Mice

Background

Since drug resistance makes controlling malaria parasites a major challenge, these pioneering researchers explore and discover new novel drugs from a variety of sources. As a result, this study aimed to assess the anti-plasmodial activity of hydroalcoholic crude extract and solvent fractions of Zehneria scabra roots in mice infected with Plasmodium berghei.

Methods

The antimalarial activity and safety profile of Zehneria scabra extracts were tested in a mouse model using four-day suppressive, prophylactic, and rane’s tests against chloroquine-sensitive Plasmodium berghei. Mice were divided into five groups at random: group I received distilled water (10 mL/kg), group II, III, and IV received 200, 400, and 600 mg/kg of the extract, respectively, and group V received chloroquine (25 mg/kg). The antimalarial activity of the extract was determined using parasitemia levels, survival time, rectal temperature, and weight variation.

Results

At all dose levels, the crude extract and solvent fractions of Zehneria scabra showed significant (p<0.05 to p<0.001) chemosuppression, with the crude extract and butanol fraction showing the highest chemosuppression (73.09% and 74.09%, respectively). Apart from suppressing parasitemia, the extract also increased survival time and secured packed cell volume reduction substantially (p<0.05 to p<0.001), while the crude extract had no significant impact on body weight or rectal temperature reduction in four-day suppressive and prophylactic models.

Conclusion

The result designated that Zehneria scabra is endowed with significant antimalarial activity. These results thus support the traditional use of Zehneria scabra, for the treatment of malaria.

Medicinal plants as a fight against murine blood-stage malaria

OBJECTIVE

Malaria is an infectious parasitic disease affecting most of countries worldwide. Due to antimalarial drug resistance, researchers are seeking to find another safe efficient source for treatment of malaria. Since many years ago, medicinal plants were widely used for the treatment of several diseases. In general, most application is done first on experimental animals then human. In this article, medicinal plants as antimalarial agents in experimental animals were reviewed from January 2000 until November 2020.

MATERIALS AND METHODS

In this systematic review published articles were reviewed using the electronic databases NCBI, ISI Web of knowledge, ScienceDirect and Saudi digital library to check articles and theses for M.Sc/Ph.D. The name of the medicinal plant with its taxon ID and family, the used Plasmodium species, plant part used and its extract type and the country of harvest were described.

RESULTS AND CONCLUSION

The reviewed plants belonged to 83 families. Medicinal plants of families Asteraceae, Meliaceae Fabaceae and Lamiaceae are the most abundant for use in laboratory animal antimalarial studies. According to region, published articles from 33 different countries were reviewed. Most of malaria published articles are from Africa especially Nigeria and Ethiopia. Leaves were the most common plant part used for the experimental malaria research. In many regions, research using medicinal plants to eliminate parasites and as a defensive tool is popular.

A review of traditional uses, phytochemistry and pharmacology of the genus Indigofera

ETHNOPHARMACOLOGICAL RELEVANCE

Indigofera is the third-largest genus in the family of Fabaceae, with approximately 750 species. It is distributed across all tropical regions. Indigofera species are widely employed in traditional medicine all around the world, against many ailments. Thus, based on these medicinal properties, various investigations have been undertaken in order to appraise the pharmacological activities and the chemical composition of these species. A recent paper provides a summary of the phytochemistry and pharmacology of the genus Indigofera. Consequently, this review is a continuation of this previous study by updating some data and adding information about the phylogeny and traditional uses of the genus.

AIM OF THE STUDY

To provide an overview of the phylogeny, traditional uses, phytochemistry, pharmacology and toxicity of the genus Indigofera, and to identify the remaining gaps and thus supply a basis for further investigations.

MATERIALS AND METHODS

A review of the literature was performed by consulting scientific databases such as 'ScienceDirect', 'PubMed', 'Google Scholar' and 'SpringerLink' and using the keyword Indigofera.

RESULTS

Over 60 Indigofera species are reported in traditional medicine. The uses depend on the country and the species, but similarities have been noticed. Indeed, treatments of gastrointestinal disorders, inflammatory conditions and pain, skin ailments, and respiratory and infectious diseases are recurring. Phytochemical studies have led to the identification of more than 200 compounds, notably flavonoids and terpenoids. Many pharmacological activities have been demonstrated, particularly antimicrobial, cytotoxic and anti-inflammatory activities, and thus allowed to assert most of the traditional uses of the genus. Some active compounds have been isolated and have shown remarkable therapeutic potential, like the alkaloid indirubin, which is currently being clinically trialed.

CONCLUSIONS

The data on the genus Indigofera are extensive, but gaps still remain. Indeed, some promising species have not been assessed for their phytochemistry and/or pharmacology and thus remain unexplored. Moreover, relatively few active compounds have been isolated and tested for their biological activity, and studies to explain their mechanism of action are nearly inexistent. Furthermore, some pharmacological studies have inappropriate methodologies that make the results difficult to interpret. Consequently, further in-depth and relevant research is required to supplement the knowledge on this wide-ranging genus and to confirm its reported therapeutic potential.

Ethnobotanical Study of Medicinal Plants Used by Traditional Healers to Treat Cancer-Like Symptoms in Eleven Districts, Ethiopia

There is no ethnobotanical study conducted specifically on medicinal plants traditionally used to treat cancer in Ethiopia. Yet, traditional herbalists in different parts of the country claim that they have been treating cancer-like symptoms using herbal remedies. The objective of this study was to document medicinal plants traditionally used to treat cancer-like symptoms in eleven districts, Ethiopia. Traditional herbalists were interviewed using semistructured questionnaires, and field visits were also carried out to collect claimed plants for identification purpose. Seventy-four traditional herbalists, who claimed that they knew about and/or had used medicinal plants to treat cancer-like symptoms, were selected using the snowball method and interviewed. Herbalists used their intuition and relied on the chronicity, growth of external mass, and spreading of the disease to other parts of the body, as a means to characterize cancer symptoms. Furthermore, in some of the study districts, herbalists reported that they treat patients who had already been diagnosed in modern healthcare institutions prior to seeking help from them. The inventory of medicinal plants is summarized in a synoptic table, which contains the scientific and vernacular names of the plants, their geographical location, the parts of the plants, and the methods used to prepare the remedies. A total of 53 traditionally used anticancer plants, belonging to 30 families, were identified during the survey. The most frequently reported anticancer plants were Acmella caulirhiza Del (Asteraceae), Clematis simensis Fresen. (Ranunculaceae), Croton macrostachyus Del. (Euphorbiaceae), and Dorstenia barnimiana Schweinf. (Moraceae). Organizing traditional healers, documenting their indigenous knowledge, and scientifically validating it for the development of better cancer therapeutic agents constitute an urgent and important task for policymakers and scientists.

Evaluation of Antimalarial Activity of the Leaf Latex and TLC Isolates from Aloe megalacantha Baker in Plasmodium berghei Infected Mice

Malaria is a devastating parasitic disease which caused around 216 million cases and 445,000 deaths worldwide in 2016. This might be attributed to a wide spread of drug resistant parasites. The plant Aloe megalacantha is indigenous to Ethiopia where the sap of the leaves is traditionally used for the treatment of malaria. This study was aimed at evaluating the antimalarial effect of leaf latex and isolates obtained from Aloe megalacantha against chloroquine sensitive Plasmodium berghei ANKA strain in Swiss albino mice. Peters' 4-day suppressive test method was used to test the antimalarial activity of both leaves latex and isolates. Three isolates were obtained using thin layer chromatography and were coded as AM₁, AM₂, and AM₃ in ascending order of their retention factor. After treatment of Plasmodium berghei infected mice with leaf latex of Aloe megalacantha for four days at 100, 200, and 400 mg/kg, it shows 30.3%, 43.4%, and 56.4% suppression of the parasite growth, respectively. 32.3%, 51.3%, and 67.4% chemosuppression after treatment with AM₁, 39.8%, 50.6%, and 64.2% chemosuppression after treatment with AM₂, and 52.6%, 69.4%, and 79.6% chemosuppression after treatment with AM₃ were observed at doses of 100, 200, and 400 mg/kg/day, respectively. The observed parasite suppression of leaves latex and isolates was statistically significant (P<0.05) as compared to negative control. Moreover, both the leaves latex and isolates were also observed to prevent Plasmodium berghei induced body weight loss and hypothermia and increased the survival time of Plasmodium berghei infected mice as compared to the negative control. Hence, the present study supports the traditional claim of the plant for the treatment of malaria.

Zingiber Officinale Roscoe and Echinops Kebericho Mesfin Showed Antiplasmodial Activities against Plasmodium Berghei in a Dose-dependent Manner in Ethiopia

BACKGROUND

The emergence and spread of Plasmodium falciparum resistance to antimalarial drugs necessitated the search for new drugs from natural products. Zingiber officinal Roscoe and Echinops Kebericho Mesfin are traditional herbal medicines widely used for the treatment of malaria in Ethiopia. The aim of the study was to assess the toxicity profile and in vivo antiplasmodial activities of 70% methanol crude extracts of both plant materials against Plasmodium berghei.

METHODS

Healthy male Swiss Albino mice of age 4-5 weeks and weight 25-36 g were infected by P. berghei. The extracts were administered orally at doses 5000, 2500 and 1250 mg/kg for acute toxicity of E. kebericho Mesfin. Graded doses at 1000, 500 and 250 mg/kg used for four days suppressive studies. Parasitemia, body weight, packed cell volume (PCV) and survival time were determined. SPSS Version 20 was used for the analysis of data of parasitemia, body weight, PCV, and survival times. Statistical significance was determined by one-way ANOVA. Independent t-test was used to compare results. Results were presented as a mean ± standard error of the mean (M ± SEM). All data were analyzed at a 95% confidence interval (α= 0.05).

RESULTS

At the dose of 5000 mg/kg, E. kebericho Mesfin showed no toxic effects. The LD50 of extract could go beyond the dose used. In vivo antiplasmodial activity of extracts showed excellent chemo suppression at 500 and 1000 mg/kg in a dose dependent manner compared with the negative control. The chemo suppressions of the 1000 mg/kg of both plant extracts were 49.53 ± 1.90% and 32.83 ± 1.03%, respectively. The survival times of P. berghei infected mice were also a dose dependent manner while failed to prevent weight loss.

CONCLUSION

The extracts of both medicinal plants showed antiplasmodial activities against P. berghei. It confirmed the literature findings and their traditional uses.

Medicinal plants used by the people of Nsukka Local Government Area, south-eastern Nigeria for the treatment of malaria: An ethnobotanical survey

ETHNOBOTANICAL RELEVANCE

Malaria is a serious public health problem especially in sub-Saharan African countries such as Nigeria. The causative parasite is increasingly developing resistance to the existing drugs. There is urgent need for alternative and affordable therapy from medicinal plants which have been used by the indigenous people for many years.

AIM OF STUDY

This study was conducted to document the medicinal plant species traditionally used by the people of Nsukka Local Government Area in south-eastern Nigeria for the treatment of malaria.

METHODS

A total of 213 respondents, represented by women (59.2%) and men (40.8%), were interviewed using a semi-structured questionnaire. The results were analysed and discussed in the context of previously published information on anti-malarial and phytochemical studies of the identified plants.

RESULTS

The survey revealed that 50 plant species belonging to 30 botanical families were used in this region for the treatment of malaria. The most cited families were Apocynaceae (13.3%), Annonaceae (10.0%), Asteraceae (10.0%), Lamiaceae (10.0%), Poaceae (10.0%), Rubiaceae (10.0%) and Rutaceae (10.0%). The most cited plant species were Azadirachta indica (11.3%), Mangifera indica (9.1%), Carica papaya (8.5%), Cymbopogon citratus (8.5%) and Psidium guajava (8.5%).

CONCLUSION

The present findings showed that the people of Nsukka use a large variety of plants for the treatment of malaria. The identified plants are currently undergoing screening for anti-malarial, toxicity and chemical studies in our laboratory.

A review of the traditional and modern uses of Salvadora persica L. (Miswak): Toothbrush tree of Prophet Muhammad

ETHNOPHARMACOLOGICAL RELEVANCE

Salvadora persica L., also known as Arak (in Arabic) and Peelu (in Urdu), is the most common traditional source of tooth or chewing stick (miswak) highly recommended by Prophet Muhammad. To date, extensive studies have probed primarily into the validation of its traditional uses in oral care. Nonetheless, there is still a dearth of updated compilation and critical analysis of other potential ethnopharmacological properties of S. persica. This review therefore aims to provide an up-to-date detailed structured description of the traditional uses of S. persica and a critical analysis of its modern uses, highlighting its phytochemistry, pharmacological properties, and bioapplications.

MATERIALS AND METHODS

Various databases (Science Direct, PubMed, Wiley Online Library, and Google Scholar), books, and relevant primary sources were probed, surveyed, analysed, and included in this review. The literature cited in this review dated from 1979 to 2017.

RESULTS

S. persica was found to possess a plethora of bioactive compounds and broad pharmacological properties, including antimicrobial, antioxidant, enzyme inhibitory activity, antiulcer, anticonvulsant, sedative, analgesic, anti-inflammatory, hypoglycemic, hypolipidemic, antiosteoporosis, and antitumor activities. Studies also revealed the potential use of S. persica as a natural food preservative and a novel functional food ingredient. In addition, improvement in growth and reproductive performances have been observed by the introduction of S. persica in animal feed. Lastly, S. persica has also been used in the green synthesis of nanoparticles showing potential biotechnological applications.

CONCLUSION

S. persica showed a wide scope of application and its uses have been extended far beyond the initial traditional uses of its roots, stems, and twigs in oral care. We found a number of other ethnopharmacological uses and potential bioapplications of different parts of S. persica that warrants further investigations. Though widely studied using several in vitro and in vivo models, and tested clinically for oral hygiene mainly, several gaps and research priorities have been identified which needs to be addressed in future.

Treatment of malaria and related symptoms using traditional herbal medicine in Ethiopia

ETHNOPHARMACOLOGICAL RELEVANCE

Medicinal plants have always been an integral part of different cultures in Ethiopia in the treatment of different illnesses including malaria and related symptoms. However, due to lack of proper documentation, urbanization, drought, acculturation and deforestation, there is an increased risk of losing this traditional knowledge. Hence, the use of the indigenous knowledge should be well documented and validated for potential future use.

AIM OF THE STUDY

To gather and document information on medicinal plants which are used in the traditional treatment of malaria and related symptoms in Ethiopia.

MATERIALS AND METHODS

First, an ethnomedicinal survey of plants was conducted in 17 districts of Jimma zone, the Oromia national regional state of Ethiopia. Jimma zone is malarious and rich in natural flora. A total of 115 traditional healers were interviewed using a semi-structured questionnaire containing personal data of the respondents, and information on medicinal plants used to treat malaria and related symptoms. In addition, a literature search using Medline/PubMed, Google Scholar, ScienceDirect and HINARI was conducted on the indigenous use, in-vitro/in-vivo anti-malarial activity reports, and the chemical characterization of medicinal plants of Ethiopia used against malaria.

RESULTS

From ethnomedicinal survey, a total of 28 species of plants used in the traditional treatment of malaria and related symptoms in Jimma Zone were collected, identified and documented. In addition, the literature search revealed that 124 medicinal plant species were reported to be traditionally used in the treatment of malaria in Ethiopia. From both ethnomedicinal survey and the literature search, Asteraceae and Fabaceae were the most represented families and Allium sativum L., Carica papaya L., Vernonia amygdalina Del., Lepidium sativum L. and Croton macrostachyus Del. were the most frequently reported plant species for their anti-malarial use. The dominant plant parts used in the preparation of remedies were leaves. About 54% of the medicinal plants documented in the survey have been reported as an anti-malarial plant in the literature search. Furthermore, the in-vitro and in-vivo anti-plasmodial activity reports of extracts from some of plant species were found to support the traditional claim of the documented plants. Moreover, literatures indicate that several secondary metabolites isolated from certain plant species that are traditionally used for the treatment of malaria and related symptoms in Ethiopia demonstrate strong anti-plasmodial activity.

CONCLUSIONS

The result of the current study showed that traditional knowledge is still playing an important role in the management of malaria and related symptoms in Ethiopia. Allium sativum L., Carica papaya L., Vernonia amygdalina Del., and Lepidium sativum L. are the most commonly reported species as anti-malarial plants and the traditional claim of some species was supported by known anti-plasmodial activity and bioactivity reports. The finding of this study is important in the rational prioritization of plant species which are potentially used for investigating new compounds, which could be efficacious for malaria treatment.

Systematic review on traditional medicinal plants used for the treatment of malaria in Ethiopia: trends and perspectives

Background

Ethiopia is endowed with abundant medicinal plant resources and traditional medicinal practices. However, available research evidence on indigenous anti-malarial plants is highly fragmented in the country. The present systematic review attempted to explore, synthesize and compile ethno-medicinal research evidence on anti-malarial medicinal plants in Ethiopia.

Methods

A systematic web search analysis and review was conducted on research literature pertaining to medicinal plants used for traditional malaria treatment in Ethiopia. Data were collected from a total of 82 Ethiopian studies meeting specific inclusion criteria including published research articles and unpublished thesis reports. SPSS Version 16 was used to summarize relevant ethno-botanical/medicinal information using descriptive statistics, frequency, percentage, tables, and bar graphs.

Results

A total of 200 different plant species (from 71 families) used for traditional malaria treatment were identified in different parts of Ethiopia. Distribution and usage pattern of anti-malarial plants showed substantial variability across different geographic settings. A higher diversity of anti-malarial plants was reported from western and southwestern parts of the country. Analysis of ethno-medicinal recipes indicated that mainly fresh leaves were used for preparation of remedies. Decoction, concoction and eating/chewing were found to be the most frequently employed herbal remedy preparation methods. Notably, anti-malarial herbal remedies were administered by oral route. Information on potential side effects of anti-malarial herbal preparations was patchy. However, some anti-malarial plants were reported to have potentially serious side effects using different local antidotes and some specific contra-indications.

Conclusion

The study highlighted a rich diversity of indigenous anti-malarial medicinal plants with equally divergent herbal remedy preparation and use pattern in Ethiopia. Baseline information gaps were observed in key geographic settings. Likewise, herbal remedy toxicity risks and countermeasures generally entailed more exhaustive investigation. Experimental research and advanced chemical analysis are also required to validate the therapeutic potential of anti-malarial compounds from promising plant species.

Electronic supplementary material

The online version of this article (doi:10.1186/s12936-017-1953-2) contains supplementary material, which is available to authorized users.

In vivo antiplasmodial activity evaluation of the leaves of Balanites rotundifolia (Van Tiegh.) Blatter (Balanitaceae) against Plasmodium berghei

Balanites rotundifolia (BR) (Van Tiegh.) Blatter (Balanitaceae) has been used in Ethiopian folk medicine to treat malaria, despite the lack of scientific validation. Therefore, the present study was carried out to evaluate the antiplasmodial activity of 80% methanol leaf extract of BR in mice. Both the 4-day suppressive test and Rane's test were employed. Three extract doses (BR100 mg/kg, BR200 mg/kg, and BR400 mg/kg/d) were given orally, and chloroquine was the standard drug administered through the same route. Outcome measures for evaluating antiplasmodial efficacy were parasitemia level, packed cell volume, survival time, and body temperature as well as body weight change. Moreover, preliminary phytochemical and acute toxicity studies were carried out. With the 4-day suppressive test, BR demonstrated dose-dependent significant reduction in parasitemia level at all test doses compared to the negative control: BR400 (67%, P<0.001), BR200 (42%, P<0.01), and BR100 (37%, P<0.05). With Rane's test as well, BR significantly (P<0.001 for all test doses) reduced the parasitemia level by 38% (BR100), 45% (BR200), and 69% (BR400) in comparison to vehicle treatment. The crude extract was estimated to have oral median lethal dose higher than 2,000 mg/kg, and the presence of alkaloids and cardiac glycosides was confirmed. Therefore, this study for the first time validated the antiplasmodial activity of crude leaf extract of BR. Further investigations for isolating specific phytochemicals and elucidating mechanisms are needed to address the quest for novel antimalarial drugs.

Ethnomedicinal uses of plants for the treatment of malaria in Soon Valley, Khushab, Pakistan

ETHNOPHARMACOLOGICAL RELEVANCE

To best of our knowledge this is the first quantitative ethno-medicinal study with the aim of documenting the indigenous knowledge and practices of using plants for malarial therapy in Soon Valley, Khushab, Pakistan. In this Valley, malaria is among the major public health problems but, until now, the population still mostly relies on herbal medicine for treatment.

MATERIALS AND METHODS

Ethno-medicinal data were documented from 63 informants by using semi-structured questionnaires and interviewing the informants about their knowledge of plants regarding malaria and related symptoms. Documented data were evaluated using the quantitative ethno-botanical indices of frequency citation (FC), relative frequency of citation (RFC), percentage of respondents having knowledge (PRK) and Jaccard index (JI).

RESULTS

A total of 70 plant species belonging to 62 genera and 34 families were recorded as anti-malarial in the study area. Solanaceae was found to be the most cited family with 7 species, followed by Fabaceae, Rutaceae and Lamiaceae with 5 species each. Ocimum americanum and Solanum incanum were the species with the highest relative frequency of citation (RFC =0.25 each) and percentage of respondents having knowledge (PRK =25.4% each), followed by Grewia tenax (RFC =0.23, PRK =23.8%), which indicates that these plants are the best species with anti-malarial properties. The most highly cited life form was found to be herbs (56%). The dominant plant part used in preparations were leaves (49%). The main mode of utilization was decoction (47%) followed by infusion (29%). In comparison, maximum similarity index is found in our study with JI (16.83) followed by (13.13). Similarity percentage of plants uses ranges from 0.81 to 16.83 while dissimilarity percentage varies from 0% to 17.65%.

CONCLUSIONS

To the best of our knowledge seven plant species, viz. Withania coagulans, Fagonia cretica, Carthamus oxyacantha, Ehretia obtusifolia, Helianthus annuus, Olea ferruginea and Vitex trifolia, are reported from this region for the first time for the treatment of malaria. This first ethno-medicinal study highlights potential sources for the development of new antimalarial drugs from indigenous knowledge of medicinal plants found in the Soon Valley, Pakistan. Such investigations could be a subject for in vitro and in vivo anti-plasmodial screening to develop new plant-based antimalarial drugs and can also be evaluated for other biological activities and novel drug discoveries.

Antimalarial Activity of the Chemical Constituents of the Leaf Latex of Aloe pulcherrima Gilbert and Sebsebe

Malaria is one of the three major global public health threats due to a wide spread resistance of the parasites to the standard antimalarial drugs. Considering this growing problem, the ethnomedicinal approach in the search for new antimalarial drugs from plant sources has proven to be more effective and inexpensive. The leaves of Aloe pulcherrima Gilbert and Sebsebe, an endemic Ethiopian plant, are locally used for the treatment of malaria and other infectious diseases. Application of the leaf latex of A. pulcherrima on preparative silica gel TLC led to the isolation of two C-glycosylated anthrones, identified as nataloin (1) and 7-hydroxyaloin (2) by spectroscopic techniques (UV, IR, ¹H- and ¹³C-NMR, HR-ESIMS). Both the latex and isolated compounds displayed antimalarial activity in a dose-independent manner using a four-day suppressive test, with the highest percent suppression of 56.2% achieved at 200 mg/kg/day for 2. The results indicate that both the leaf latex of A. pulcherrima and its two major constituents are endowed with antiplasmodial activities, which support the traditional use of the leaves of the plant for the treatment of malaria.

Survey of Medicinal Plants Used to Treat Malaria by Sidama People of Boricha District, Sidama Zone, South Region of Ethiopia

In Ethiopia, malaria control has been complicated due to resistance of the parasite to the current drugs. Thus, new drugs are required against drug-resistant Plasmodium strains. Historically, many of the present antimalarial drugs were discovered from plants. This study was, therefore, conducted to document antimalarial plants utilized by Sidama people of Boricha District, Sidama Zone, South Region of Ethiopia. An ethnobotanical survey was carried out from September 2011 to February 2012. Data were collected through semistructured interview and field and market observations. Relative frequency of citation (RFC) was calculated and preference ranking exercises were conducted to estimate the importance of the reported medicinal plants in Boricha District. A total of 42 antimalarial plants belonging to 27 families were recorded in the study area. Leaf was the dominant plant part (59.0%) used in the preparation of remedies and oral (97.4%) was the major route of administration. Ajuga integrifolia scored the highest RFC value (0.80). The results of this study revealed the existence of rich knowledge on the use of medicinal plants in the study area to treat malaria. Thus, an attempt should be made to conserve and evaluate the claimed antimalarial medicinal plants with priority given to those that scored the highest RFC values.

Evaluation of the antiplasmodial properties of selected plants in southern Ethiopia

BACKGROUND

The majority of the Ethiopian population is at risk of malaria largely caused by Plasmodium falciparum. The resistance of the parasite to existing drugs is the main challenge in the control of the disease and thus new therapeutic drugs are required. In Ethiopia, people use different plant species to treat malaria. However, very few of them have so far been evaluated for their safety level and antimalarial activity. Thus, the aim of this study was to evaluate the safety and antimalarial activity of extracts of Ajuga integrifolia, Clerodendrum myricoides, Melia azedarach, Peponium vogelii and Premna schimperi, locally used by the Sidama people of Ethiopia to treat malaria.

METHODS

The safety level of 80 % methanol extracts of the plants were evaluated using standard acute toxicity test procedure. The antiplasmodial activity of 80 % methanol extracts of the plants were assessed in vivo using Swiss albino mice against chloroquine sensitive rodent malaria parasite, Plasmodium berghei, using the standard 4-day suppressive test procedure at doses of 200,400 and 800 mg/kg/day. The 80 % methanol extract of Ajuga integrifolia that exhibited better antimalarial activity was fractionated using different solvents and screened for its phytochemical constituents and evaluated in vivo for its antimalarial activity at doses of 100, 200 and 400 mg/kg/day.

RESULTS

All extracts given at the three different doses caused no lethal effect on mice in 24 h and within 10 days of observation. All extracts and fractions exhibited antimalarial activity in a dose dependant manner. The highest inhibition was exhibited by the crude extracts of A. integrifolia (35.17 %) at 800 mg/kg/day (P < 0.05). Among fractions of A. integrifolia, n-butanol fraction demonstrated the highest inhibition (29.80 %) at 400 mg/kg/day (P < 0.05). The extracts and fractions prolonged the survival time and prevented weight loss of the mice, but did not prevent PCV reduction. Phytochemical test on Ajuga integrifolia indicated the presence of alkaloids, flavonoids, saponins, terpenoids, anthraquinone, steroids, tannins, phenols and fatty acids.

CONCLUSIONS

Findings show that the plants are non-toxic and demonstrate antimalarial activity in a dose dependant manner suporting claims of their traditional therapeutic value for malaria treatment. However, further in-depth investigation is required to assess the potential of the plants towards the development of new antimalarial agent.

In vitro and in vivo anti-malarial activity of plants from the Brazilian Amazon

BACKGROUND

The anti-malarials quinine and artemisinin were isolated from traditionally used plants (Cinchona spp. and Artemisia annua, respectively). The synthetic quinoline anti-malarials (e.g. chloroquine) and semi-synthetic artemisinin derivatives (e.g. artesunate) were developed based on these natural products. Malaria is endemic to the Amazon region where Plasmodium falciparum and Plasmodium vivax drug-resistance is of concern. There is an urgent need for new anti-malarials. Traditionally used Amazonian plants may provide new treatments for drug-resistant P. vivax and P. falciparum. Herein, the in vitro and in vivo antiplasmodial activity and cytotoxicity of medicinal plant extracts were investigated.

METHODS

Sixty-nine extracts from 11 plant species were prepared and screened for in vitro activity against P. falciparum K1 strain and for cytotoxicity against human fibroblasts and two melanoma cell lines. Median inhibitory concentrations (IC50) were established against chloroquine-resistant P. falciparum W2 clone using monoclonal anti-HRPII (histidine-rich protein II) antibodies in an enzyme-linked immunosorbent assay. Extracts were evaluated for toxicity against murine macrophages (IC50) and selectivity indices (SI) were determined. Three extracts were also evaluated orally in Plasmodium berghei-infected mice.

RESULTS

High in vitro antiplasmodial activity (IC50 = 6.4-9.9 µg/mL) was observed for Andropogon leucostachyus aerial part methanol extracts, Croton cajucara red variety leaf chloroform extracts, Miconia nervosa leaf methanol extracts, and Xylopia amazonica leaf chloroform and branch ethanol extracts. Paullinia cupana branch chloroform extracts and Croton cajucara red variety leaf ethanol extracts were toxic to fibroblasts and or melanoma cells. Xylopia amazonica branch ethanol extracts and Zanthoxylum djalma-batistae branch chloroform extracts were toxic to macrophages (IC50 = 6.9 and 24.7 µg/mL, respectively). Andropogon leucostachyus extracts were the most selective (SI >28.2) and the most active in vivo (at doses of 250 mg/kg, 71% suppression of P. berghei parasitaemia versus untreated controls).

CONCLUSIONS

Ethnobotanical or ethnopharmacological reports describe the anti-malarial use of these plants or the antiplasmodial activity of congeneric species. No antiplasmodial activity has been demonstrated previously for the extracts of these plants. Seven plants exhibit in vivo and or in vitro anti-malarial potential. Future work should aim to discover the anti-malarial substances present.

Plants as antimalarial agents in Sub-Saharan Africa

Although the burden of malaria is decreasing, parasite resistance to current antimalarial drugs and resistance to insecticides by vector mosquitoes threaten the prospects of malaria elimination in endemic areas. Corollary, there is a scientific departure to discover new antimalarial agents from nature. Because the two antimalarial drugs quinine and artemisinin were discovered through improved understanding of the indigenous knowledge of plants, bioprospecting Sub-Saharan Africa's enormous plant biodiversity may be a source of new and better drugs to treat malaria. This review analyses the medicinal plants used to manage malaria in Sub-Saharan Africa. Chemical compounds with antiplasmodial activity are described. In the Sub-Saharan African countries cited in this review, hundreds of plants are used as antimalarial remedies. While the number of plant species is not exhaustive, plants used in more than one country probably indicate better antimalarial efficacy and safety. The antiplasmodial data suggest an opportunity for inventing new antimalarial drugs from Sub-Saharan-African flora.

Enzymatic Characterization of Recombinant Food Vacuole Plasmepsin 4 from the Rodent Malaria Parasite Plasmodium berghei

The rodent malaria parasite Plasmodium berghei is a practical model organism for experimental studies of human malaria. Plasmepsins are a class of aspartic proteinase isoforms that exert multiple pathological effects in malaria parasites. Plasmepsins residing in the food vacuole (FV) of the parasite hydrolyze hemoglobin in red blood cells. In this study, we cloned PbPM4, the FV plasmepsin gene of P. berghei that encoded an N-terminally truncated pro-segment and the mature enzyme from genomic DNA. We over-expressed this PbPM4 zymogen as inclusion bodies (IB) in Escherichia coli, and purified the protein following in vitro IB refolding. Auto-maturation of the PbPM4 zymogen to mature enzyme was carried out at pH 4.5, 5.0, and 5.5. Interestingly, we found that the PbPM4 zymogen exhibited catalytic activity regardless of the presence of the pro-segment. We determined the optimal catalytic conditions for PbPM4 and studied enzyme kinetics on substrates and inhibitors of aspartic proteinases. Using combinatorial chemistry-based peptide libraries, we studied the active site preferences of PbPM4 at subsites S1, S2, S3, S1’, S2’ and S3’. Based on these results, we designed and synthesized a selective peptidomimetic compound and tested its inhibition of PbPM4, seven FV plasmepsins from human malaria parasites, and human cathepsin D (hcatD). We showed that this compound exhibited a >10-fold selectivity to PbPM4 and human malaria parasite plasmepsin 4 orthologs versus hcatD. Data from this study furthesr our understanding of enzymatic characteristics of the plasmepsin family and provides leads for anti-malarial drug design.

Medicinal plants and finished marketed herbal products used in the treatment of malaria in the Ashanti region, Ghana

ETHNOPHARMACOLOGICAL RELEVANCE

Ethnobotanical survey was performed to document medicinal plants employed in the management of malaria in the Bosomtwe and Sekyere East Districts of the Ashanti Region (Ghana), in comparison with the plant ingredients in herbal antimalarial remedies registered by the Ghana Food and Drug Administration.

MATERIALS AND METHODS

Two hundred and three (203) herbalists from 33 communities within the two districts were interviewed on medicinal plants they use to manage malaria. A literature search was made to determine already documented plants. In addition, 23 finished marketed herbal products indicated for the management of malaria were identified and their labels examined to find out which of the plants mentioned in our survey were listed as ingredients and whether these products are in anyway regulated.

RESULTS

Ninety-eight (98) species of plants were cited for the management of malaria. In comparison with literature citations, 12 (12.2%) species were reported for the management of malaria for the first time and 20 (20.4%) others for the first time in Ghana. Twenty-three (23) finished marketed herbal antimalarial products examined contained aerial or underground parts of 29 of the plants cited in our survey as ingredients. Twenty-two (22) of these products have been registered by the Ghana Food and Drugs Authority, four (4) of which were included in the recommended herbal medicine list for treating malaria in Ghana.

CONCLUSION

This study provides new additions to the inventory of medicinal plants used for the management of malaria and reports the commercial availability and regulation of finished marketed labelled herbal products intended for the treatment of malaria in Ghana.

Antimalarial evaluation of the leaf latex of Aloe citrina and its major constituent

Background:

Malaria is one of the major obstacles to the socioeconomic development of several developing countries. Adequate treatment of the disease is becoming increasingly difficult due to the worsening problems of drug resistance in many parts of the world. Therefore, increased efforts in antimalarial drug discovery are urgently needed.

Objectives:

This study was designed to evaluate the antimalarial activity of the leaf latex of Aloe citrina Carter and Brandham and its major constituent.

Materials and Methods:

The leaf latex of A. citrina was dissolved in methanol and subjected to preparative thin layer chromatography. Structure of the isolated compound was determined on the basis of its electrospray-ionization tandem mass spectrometry, ¹H, ¹³C NMR and DEPT spectral data. The latex and its isolated compound were tested for their in vivo antimalarial activity using a 4-day suppressive test against chloroquine sensitive ANKA strain of Plasmodium berghei in mice.

Results:

Homonataloin A/B was isolated as a major component of the latex. Both the latex and isolated compound exhibited significant (P < 0.001) antimalarial activity at a dose of 400 mg/kg with parasite suppression of 60.59% and 67.52%, respectively. No significant adverse signs of toxicity were observed in mice treated with the leaf latex up to the highest dose (5000 mg/kg).

Conclusion:

The results of this study indicate that the antimalarial activity of the plant is attributed in part or in full to the presence of homonataloin A/B in the latex. It also validates the traditional use of the plant as an antimalarial agent.

Evaluation of antimalarial activity of leaves of Acokanthera schimperi and Croton macrostachyus against Plasmodium berghei in Swiss albino mice

BACKGROUND

Malaria is one of the most important tropical diseases and the greatest cause of hospitalization and death. Recurring problems of drug resistance are reinforcing the need for finding new antimalarial drugs. In this respect, natural plant products are the main sources of biologically active compounds and have potential for the development of novel antimalarial drugs. A study was conducted to evaluate extracts of the leaves of Croton macrostachyus and Acokanthera schimperi for their in vivo antimalarial activity.

METHODS

The plants were selected based on their ethnomedicinal information. Acute and sub- acute toxicity studies of the crude extracts were carried out in Swiss albino mice. To assess the effect of extracts of the plants on the parasite, a 4-day suppressive standard test was performed using Plasmodium berghei (ANKA strain). Data were analyzed using paired t-test and ANOVA.

RESULTS

In acute toxicity study, the two plants extracts did not show any sign of toxicity up to 2000 mg/kg. In sub-acute toxicity study, both plants did not exhibit any hematological change and mortality throughout the observation period up to the highest dose of 1000 mg/kg given daily. Extracts of the leaves of both plants significantly (P < 0.05) suppressed parasitaemia in dose dependent manner at all dose levels.

CONCLUSIONS

The findings may support the traditional use of the plants to treat malaria. Further pharmacological, toxicological and phytochemical studies are, however, required to evaluate the potential of the plants towards the development of new antimalarial agent.

Foeniculum vulgare Mill: a review of its botany, phytochemistry, pharmacology, contemporary application, and toxicology

Foeniculum vulgare Mill commonly called fennel has been used in traditional medicine for a wide range of ailments related to digestive, endocrine, reproductive, and respiratory systems. Additionally, it is also used as a galactagogue agent for lactating mothers. The review aims to gather the fragmented information available in the literature regarding morphology, ethnomedicinal applications, phytochemistry, pharmacology, and toxicology of Foeniculum vulgare. It also compiles available scientific evidence for the ethnobotanical claims and to identify gaps required to be filled by future research. Findings based on their traditional uses and scientific evaluation indicates that Foeniculum vulgare remains to be the most widely used herbal plant. It has been used for more than forty types of disorders. Phytochemical studies have shown the presence of numerous valuable compounds, such as volatile compounds, flavonoids, phenolic compounds, fatty acids, and amino acids. Compiled data indicate their efficacy in several in vitro and in vivo pharmacological properties such as antimicrobial, antiviral, anti-inflammatory, antimutagenic, antinociceptive, antipyretic, antispasmodic, antithrombotic, apoptotic, cardiovascular, chemomodulatory, antitumor, hepatoprotective, hypoglycemic, hypolipidemic, and memory enhancing property. Foeniculum vulgare has emerged as a good source of traditional medicine and it provides a noteworthy basis in pharmaceutical biology for the development/formulation of new drugs and future clinical uses.

Enhanced antimalarial activity by a novel artemether-lumefantrine lipid emulsion for parenteral administration

Artemether and lumefantrine (also known as benflumetol) are difficult to formulate for parenteral administration because of their low aqueous solubility. Cremophor EL as an emulsion excipient has been shown to cause serious side effects. This study reports a method of preparation and the therapeutic efficacies of novel lipid emulsion (LE) delivery systems with artemether, lumefantrine, or artemether in combination with lumefantrine, for parenteral administration. Their physical and chemical stabilities were also evaluated. Furthermore, the in vivo antimalarial activities of the lipid emulsions developed were tested in Plasmodium berghei-infected mice. Artemether, lumefantrine, or artemether in combination with lumefantrine was encapsulated in an oil phase, and the in vivo performance was assessed by comparison with artesunate for injection. It was found that the lumefantrine lipid emulsion (LUM-LE) and artemether-lumefantrine lipid emulsion (ARM-LUM-LE-3) (1:6) began to decrease the parasitemia levels after only 3 days, and the parasitemia inhibition was 90% at doses of 0.32 and 0.27 mg/kg, respectively, with immediate antimalarial effects greater than those of the positive-control group and constant antimalarial effects over 30 days. LUM-LE and ARM-LUM-LE-3 demonstrated the best performance in terms of chemical and physical stabilities and antiplasmodial efficacy, with a mean particle size of 150 nm, and they have many favorable properties for parenteral administration, such as biocompatibility, physical stability, and ease of preparation.

Ethnomedicinal plants used to treat human ailments in the prehistoric place of Harla and Dengego valleys, eastern Ethiopia

BACKGROUND

Traditional medicines remained as the most affordable and easily accessible source of treatment in the primary health care system among diverse communities in Ethiopia. The Oromo community living in the prehistoric Harla and Dengego valleys has long history of ethnomedicinal know-how and practice against human and livestock ailments. However, this rich ethnomedicinal knowledge had been remained unexplored hitherto. This study focus on the comprehensive ethnomedicinal investigation in an attempt to safeguard the deteriorating ethnomedicinal knowledge that can be used as a stepping-stone for phytochemical and pharmacological analysis.

METHODS

Fifty five (44 male and 11 female) systematically selected informants including ten traditional herbalists (key informants) were participated in the study. Semi-structured interviews, discussions and guided field walk constituted the data collection methods. Factor of informant consensus (Fic), frequency of citation (F%), and binomial test were employed in data analysis. Medicinal plant specimens were collected, identified and kept at Herbarium of Haramaya University (HHU).

RESULTS

A total of 83 traditional medicinal plant species against human ailments in 70 genera and 40 Families were recorded. Twelve medicinal plants were marketable in open market places of the nearby towns. Formulations recorded added to 140 remedies for 81 human ailments. Concoction accounts 50.7% of the total preparations followed by fluids extraction (10.7%) and infusion (6.4%). Fifteen different plant parts were used for remedies preparation wherein leaves accounted 46.4%, stem 9.2%, fruits and roots each 7.8%. Most of the remedies (90.7%) were prepared from single plant species like, aphrodisiac fresh rhizome of Kleinia abyssinica (A. Rich.) A. Berger chewed and swallowed few hours before sexual performance for a man having problem of erectile dysfunction. The Fic value ranges between 1.0 (gastritis and heartburn/pyrosis) and 0.77 (swollen body part). Aloe harlana Reynolds was reported to be used for the highest number of ailments treating swollen body part locally called GOFLA, colon cleaner, snake bite, liver swelling, spleen swelling/splenomegaly, fungal infections and inflammation of skin.

CONCLUSION

Such documentation of comprehensive ethnomedicinal knowledge is very valuable and needs to be scaled-up so that it could be followed up with phytochemical and pharmacological analyses in order to give scientific ground to the ethnomedicinal knowledge.

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

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

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.

Pharmacodynamic evaluation for antiplasmodial activity of Holarrhena antidysentrica (Kutaja) and Azadirachta indica (Neemb) in Plasmodium berghei infected mice model

OBJECTIVE

To investigate in-vivo anti-plasmodial activity of aqueous extracts of plants selected based on the symptomology mentioned in Ayurveda.

METHODS

The aqueous extracts of Holarrhena antidysentrica (H. antidysentrica) (Kutaja) and Azadirachta indica (A. indica) (Neemb) for their antiplasmodial potential in Plasmodium berghei (P. berghei) infected mice was assessed using Peters four day suppressive test. Both the extracts were administered at 2 dose levels, full dose (1 000 mg/d) and minimized dose (200 mg/d). 10(6)P. berghei infected RBCs were injected on day '0' and treated from day '0' till day '3' post-infection. Tail blood smears were collected, giemsa stained and analyzed. The mice were observed for survival and parasitemia was assessed till 50% of mice in control survived.

RESULTS

It was observed that the percentage of parasitemia increased gradually in all the groups, with maximum in control group (Day 3-35, Day 9-46.98) and minimum in Chloroquine arm (Day 3-14.06, Day 9-19.92). The percentage of parasitemia was compared using Mann-Whitney U test depicting that all test groups exhibited reduction in parasitemia as compared to control (P-value<0.002 for all groups). These groups showed similar percentage of survival as Chloroquine.

CONCLUSIONS

The present investigation demonstrated the anti-plasmodial effects of H. antidysentrica and A. indica, which are two most commonly used medicinal plants in Ayurved for treatment of fever.

Ethnobotanical survey of malaria prophylactic remedies in Odisha, India

AIM OF THE STUDY

To investigate the plants traditionally used for prevention of malaria in Cuttack, Gajapati and Koraput districts of Odisha state, eastern India.

MATERIALS AND METHODS

An ethnobotanical survey was carried out among 20 traditional healers who were sampled based on recommendations of local elders and local non-government organizations. Data were collected through semi-structured interview.

RESULTS

The study revealed the use of 16 traditional plant species belonging to 12 families for prevention of malaria. Andrographis paniculata, Azadirachta indica, Nyctanthes arbor-tristis, Ocimum sanctum, Piper nigrum, Zingiber officinale were the most commonly reported plants for their malaria prophylactic use by the healers of three districts of Odisha. Most of the remedies were used in decoction form.

CONCLUSIONS

Findings of this study provide a lead to explore traditional plants for malaria preventive potential through further pre-clinical and clinical studies.