The antiplasmodial effect of the extracts and formulated capsules of Phyllanthus amarus on Plasmodium yoelii infection in mice

An insight into the potent medicinal plant Phyllanthus amarus Schum. and Thonn

Phyllanthus amarus Schum. and Thonn., a globally distributed herb is known for its several therapeutic potentials. P. amarus has a long history of use in the traditional system of medicine for over 2000 years owing to its wide array of secondary metabolites that confer significant medicinal attributes. Research on various aspects including ethnobotany, phytochemistry to bioactivity, or pharmacological studies has been conducted over the past several decades on this potent herb. P. amarus extracts have shown a broad range of pharmacological activities like hepatoprotective, antioxidant, antiviral, antimicrobial, antidiabetic, anti-inflammatory, anticancer, antimalarial, nephroprotective, diuretic, and several other properties. The present review compiles and covers literature and research of several groups across past decades to date and focuses on how the therapeutic significance of this plant can be further explored for future research either as herbal formulations, alternative medicine, or in the pharmaceutical industry.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13237-022-00409-z.

Wild Egyptian medicinal plants show in vitro and in vivo cytotoxicity and antimalarial activities

Background

Medicinal plants have been successfully used as an alternative source of drugs for the treatment of microbial diseases. Finding a novel treatment for malaria is still challenging, and various extracts from different wild desert plants have been reported to have multiple medicinal uses for human public health, this study evaluated the antimalarial efficacy of several Egyptian plant extracts.

Methods

We assessed the cytotoxic potential of 13 plant extracts and their abilities to inhibit the in vitro growth of Plasmodium falciparum (3D7), and to treat infection with non-lethal Plasmodium yoelii 17XNL in an in vivo malaria model in BALB/c mice.

Results

In vitro screening identified four promising candidates, Trichodesma africanum, Artemisia judaica, Cleome droserifolia, and Vachellia tortilis, with weak-to-moderate activity against P. falciparum erythrocytic blood stages with mean half-maximal inhibitory concentration 50 (IC₅₀) of 11.7 μg/ml, 20.0 μg/ml, 32.1 μg/ml, and 40.0 μg/ml, respectively. Their selectivity index values were 35.2, 15.8, 11.5, and 13.8, respectively. Among these four candidates, T. africanum crude extract exhibited the highest parasite suppression in a murine malaria model against P. yoelii.

Conclusion

Our study identified novel natural antimalarial agents of plant origin that have potential for development into therapeutics for treating malaria.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03566-5.

When local phytotherapies meet biomedicine. Cross-sectional study of knowledge and intercultural practices against malaria in Eastern French Guiana

ETHNOPHARMACOLOGICAL RELEVANCE

In French Guiana, traditional phytotherapies are an important part of self-healthcare, however, a precise understanding of the interactions between local phytotherapies and biomedicine is lacking. Malaria is still endemic in the transition area between French Guiana and Brazil, and practices of self-treatment, although difficult to detect, have possible consequences on the outcome of public health policies.

AIM OF THE STUDY

The objectives of this research were 1) to document occurences of co-medication (interactions between biomedicine and local phytotherapies) against malaria around Saint-Georges de l'Oyapock (SGO), 2) to quantify and to qualify plant uses against malaria, 3) and to discuss potential effects of such co-medications, in order to improve synergy between community efforts and public health programs in SGO particularly, and in Amazonia more broadly.

MATERIALS AND METHODS

This cross-sectional study was conducted in 2017 in SGO. Inhabitants of any age and nationality were interviewed using a questionnaire (122 questions) about their knowledge and habits regarding malaria, and their use of plants to prevent and treat it. They were invited to show their potential responses on a poster illustrating the most common antimalarial plants used in the area. In order to correlate plant uses and malaria epidemiology, all participants subsequently received a medical examination, and malaria detection was performed by Rapid Diagnostic Test (RDT) and Polymerase Chain Reaction (PCR).

RESULTS

A total of 1566 inhabitants were included in the study. Forty-six percent of them declared that they had been infected by malaria at least once, and this rate increased with age. Every person who reported that they had had malaria also indicated that they had taken antimalarial drugs (at least for the last episode), and self-medication against malaria with pharmaceuticals was reported in 142 cases. A total of 550 plant users was recorded (35.1% of the interviewed population). Among them 95.5% associated pharmaceuticals to plants. All plants reported to treat malaria were shared by every cultural group around SGO, but three plants were primarily used by the Palikur: Cymbopogon citratus, Citrus aurantifolia and Siparuna guianensis. Two plants stand out among those used by Creoles: Eryngium foetidum and Quassia amara, although the latter is used by all groups and is by far the most cited plant by every cultural group. Cultivated species accounts for 91.3% of the use reports, while wild taxa account for only 18.4%.

CONCLUSIONS

This study showed that residents of SGO in French Guiana are relying on both traditional phytotherapies and pharmaceutical drugs to treat malaria. This medical pluralism is to be understood as a form of pragmatism: people are collecting or cultivating plants for medicinal purposes, which is probably more congruent with their respective cultures and highlights the wish for a certain independence of the care process. A better consideration of these practices is thus necessary to improve public health response to malaria.

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.

Survey of ethnobotanical cocktails commonly used in the treatment of malaria in southwestern Nigeria

Background

Combination of different antimalarials has become the popular method of care for malaria morbidity in conventional and traditional treatment approaches due to the need to increase the efficacy and reduce the selection of drug resistance. A worrisome concern is the critical gaps with regards to the information available on antimalarial herbal cocktails. This study presents cocktail herbal remedies in ethnomedicinal approaches to malaria treatment in Oyo and Ogun states, South West Nigeria. Ethnobotanical information on indigenous antimalarials used in combination remedies was collected from herbal practitioners using a semi-structured questionnaire.

Results

Findings showed majority of respondents treat malaria with combination herbal remedies. They sighted their beliefs and customs, the efficacy, affordability and availability of these herbs as reasons for their adoption of herbal medicines as their preferred mode of treating malaria. Enquiry revealed 26 sets of cocktail antimalarials from a variety of plant species. The plants and ingredients are extracted and used as decoction, infusion or steam baths. Oral route was the most popular mode of administration. Respondents reported they drink one to two medium-sized cups of the recipe on an average of two times daily within a duration of about 10 days.

Conclusions

Herbal antimalarial remedies continue to be the popular treatments option in our localities. This study provides knowledge of the diverse ways respondents combine medicinal herbs and other local ingredients for malaria treatment. Pharmacological screening is urgently needed to validate their safety and efficacy in order to protect the health of our locals heavily relying on them to combat high burdens of malaria.

African Herbal Medicines: Adverse Effects and Cytotoxic Potentials with Different Therapeutic Applications

The African continent is naturally endowed with various plant species with nutritional and medicinal benefits. About 80% of the people in developing countries rely on folk medicines to treat different diseases because of indigenous knowledge, availability, and cost-effectiveness. Extensive research studies have been conducted on the medicinal uses of African plants, however, the therapeutic potentials of some of these plants has remained unexploited. Over the years, several studies have revealed that some of these African floras are promising candidates for the development of novel drugs. Despite the plethora of studies on medicinal plant research in Africa, there is still little scientific data supporting the folkloric claims of these plants. Besides, safety in the use of folk medicines has been a major public health concern over the year. Therefore, it has become mandatory that relevant authority should take measures in safeguarding the populace on the use of herbal mixtures. Thus, the present review extracted relevant information from different scientific databases and highlighted some problems associated with folk medicines, adverse effects on reproductive systems, issue about safety due to the toxicity of some plants and their toxicity effects with potential therapeutic benefits are discussed.

Assessment of the Diversity of Medico-Magic Knowledge on Four Herbaceous Species in Benin

Background

Ethnobotanical knowledge on four herbaceous species, Acmella uliginosa (Sw.) Cass., Momordica charantia L., Phyllanthus amarus Schumach. & Thonn., and Scoparia dulcis L., in Benin was investigated.

Methods

Herbal medicine traders in six different markets were interviewed using a semi-structured questionnaire. The linear regression test was performed to check for the influence of respondent's age on ethnobotanical uses they hold. Relative frequency citation, fidelity level, use value, and Rahman similarity index were calculated to assess the diversity of medico-magic knowledge. The Informant Consensus Factor is not applicable in this study since we are dealing neither with the diversity of medicinal plants used by a community of people nor with a great number of plant species used for medicinal purposes, nor the diversity of plant species used in the treatment of a specific or group of ailments.

Results

The respondent's age did not influence the ethnobotanical uses they hold on the species. All thirty-six informants surveyed traded Phyllanthus amarus Schumach. & Thonn., Momordica charantia L., and Scoparia dulcis L., and the majority traded Acmella uliginosa (Sw.) Cass. The respondent's age does not influence the diversity of ethnobotanical uses they hold on the study species. Purchase in traders' own markets was the predominant source of Phyllanthus amarus Schumach. & Thonn., Momordica charantia L., and Scoparia dulcis L. while Acmella uliginosa (Sw.) Cass. was mostly purchased in other more distant markets. A noticeable proportion of traders also collect Phyllanthus amarus Schumach. & Thonn. and Momordica charantia L. from wild populations. Phyllanthus amarus Schumach. & Thonn. was the species most demanded by customers followed by Momordica charantia L. Traders confirmed the scarcity of all species in recent years and climate change and destruction of natural habitats for logging were the most cited causes. The entire plant of Phyllanthus amarus Schumach. & Thonn. was used mainly to treat malaria, diabetes, and constipation, and decoction with oral administration was the most frequent preparation for malaria treatment. To treat diabetes, informants mixed Phyllanthus amarus Schumach. & Thonn. with Momordica charantia L. used as a decoction with oral administration. Momordica charantia L. was also used to treat measles and chicken pox. Acmella uliginosa (Sw.) Cass. and Scoparia dulcis L. were mostly used for their spiritual use for luck, predominantly by chewing fresh leaves or flowers, and by bathing with the ground plant mixed with soap, respectively. Overall, Momordica charantia L. had the greatest use value followed by Phyllanthus amarus Schumach. & Thonn. The majority of traders do not plant the species.

Conclusions

The harvesting and trade of the species threaten their natural populations and urgent tools, including in situ and ex situ conservation, are needed to ensure their long-term sustainable exploitation.

In vitro antiplasmodial activity of Phyllanthus amarus against Plasmodium falciparum and evaluation of its acute toxicity effect in mouse model

Background:

The emergence of widespread resistance of Plasmodium species to most antimalarial drugs has led to a more vigorous and concerted research on traditional medicinal plants for the treatment of malaria.

Objective of Study:

The study was aimed to investigate the in vitro antiplasmodial activity of crude ethanolic and aqueous extracts of Phyllanthus amarus against clinical isolates of Plasmodium falciparum in Northwestern Nigeria.

Materials and Methods:

The plant was extracted using two solvents, water and ethanol, where a high yield was obtained from the aqueous extracts (11.9%) as compared to the ethanolic extract (9.64%). The extracts were evaluated in vitro at concentrations of 6.25, 12.5, 25, 50, and 100 μg/ml, and the level of potency in each case was expressed as the concentration of the extract that exhibited a 50% reduction of the parasites relative to control (100%) parasitemia. Artemether-lumefantrine was used as a positive standard in the assay.

Results:

All extracts showed a significant reduction in parasite growth relative to control (P ≤ 0.05). Ethanolic extract exhibited a higher antiplasmodial activity of 76.8%, half-maximal inhibitory concentration (IC₅₀) of 5.80 μg/ml, and aqueous extract had an activity of 75.3%, IC₅₀ of 7.94 μg/ml. Both extracts exhibited very active antiplasmodial activity. Oral acute toxicity test in the doses of 500, 1000, and 1500 mg/kg showed no sign of toxicity on albino mice after 48 h.

Conclusion:

Although there was an increase in appetite after 24 and 48 h, the findings from this study show that P. amarus possesses a promising antimalarial activity which can be exploited for malaria therapy and justifies the traditional use of the plant in malaria treatment.

Antimalarial properties and preventive effects on mitochondrial dysfunction by extract and fractions of Phyllanthus amarus (Schum. and Thonn) in Plasmodium berghei-infected mice

OBJECTIVES

Broad spectrum antimalarial drugs without deleterious effects on mitochondria are scarce. It is in this regard that we investigated the potency of methanol extract and solvent fractions of Phyllanthus amarus on chloroquine-susceptible and resistant strains of Plasmodium berghei, toxicity and its consequential effects on mitochondrial permeability transition (mPT) pore opening.

METHODS

Malaria was induced in male Swiss mice with susceptible (NK 65) strain, divided into groups (n=5) and treated with 100, 200 and 400 mg/kg of methanol extract, n-hexane, dichloromethane, ethylacetate and methanol fractions daily for seven days. Percentage parasitemia and parasite clearance were determined microscopically. The two most potent fractions were tested on resistant (ANKA) strains. Heme and hemozoin contents were determined spectrophotometrically. The mPT, mitochondrial ATPase (mATPase) and lipid peroxidation (mLPO) were determined spectrophotometrically. Similar groups of animals were used for toxicity studies.

RESULTS

Dichloromethane fraction (400 mg/kg) had the highest antimalarial curative effect via least parasitemia (0.49) and high clearance (96.63) compared with the negative control (10.08, 0.00, respectively), had the highest heme and least hemozoin contents (16.23; 0.03) compared with the negative control (8.2, 0.126, respectively). Malaria infection opened the mPT, caused significant increase in mLPO and enhanced mATPase; while dichloromethane fraction reversed these conditions. Serum ALT, AST, ALP, GGT, urea and creatinine of dichloromethane fraction-treated mice decreased relative to control. No significant lesion was noticed in liver and kidney tissue sections.

CONCLUSIONS

Dichloromethane fraction of Phyllanthus amarus had the highest antimalarial activity with the highest mito-protective effect and it was well tolerated without toxic effects.

Antimalarial Activity of Ethyl Acetate Extract and Fraction of Bidens pilosa against Plasmodium berghei (ANKA)

Background

Malaria is one of the most critical diseases causing about 219 million cases worldwide in developing countries. The spread and development of resistance against chemical antimalarial drugs is one of the major problems associated with malaria control. The present study was to investigate the antimalarial efficacy of ethyl acetate extract and one fraction of Bidens pilosa in vivo in order to support the usage of this plant by traditional healers to treat malaria.

Methods

The extracts were prepared by maceration of B. pilosa leaf powder in ethyl acetate. The liquid filtrate of the extract and the best in vitro antiplasmodial fraction using HPLC were concentrated and evaporated using a rotavapor under vacuum to dryness. The antimalarial activity of B. pilosa plant products were evaluated in vivo against Plasmodium berghei infected mice according to the Peter and Rane test. The antimalarial efficacy of the a selected crude extract (ethyl acetate extract) was evaluated at 125, 250, and 500 mg/kg, while a selected fraction from ethyl acetate extract (fraction 12) was evaluated at 62.5 and 125 mg/kg. Blood from experimental animals was collected to assess hematological parameters.

Results

The crude extract of ethyl acetate and fraction 12 demonstrated 100% in vivo parasite suppressive activity at doses of 500 mg/kg and 125 mg/kg, respectively, for the crude extract and fraction 12. The mice treated with 250 and 500 mg/kg had their parasitemia (intraerythrocytic phase of P. Berghei) drop considerably, disappearing by the 8^th day in mice receiving 500 mg/kg. The ethyl acetate extract of B. pilosa, fraction 12 showed an even higher antiplasmodial activity. By the 5^th day of the experiment, the treatment led to a modification of hematological parameters in mice. The chloroquine (5 mg/kg), fraction 12 (125 mg/kg), and the crude extract (500 mg/kg) groups all survived the 30 days of the experiment, while the negative control group registered 100% of the deaths.

Conclusion

This study scientifically supports the use of Bidens pilosa leaves in the traditional treatment of malaria. However, the mode of action and in vivo toxicity of the plant still need to be assessed.

In vivo antimalarial activity of extracts of Tanzanian medicinal plants used for the treatment of malaria

Plants used in traditional medicine have been the source of a number of currently used antimalarial medicines and continue to be a promising resource for the discovery of new classes of antimalarial compounds. The aim of this study was to evaluate in vivo antimalarial activity of four plants; Erythrina schliebenii Harms, Holarrhena pubescens Buch-Ham, Phyllanthus nummulariifolius Poir, and Caesalpinia bonducella (L.) Flem used for treatment of malaria in Tanzania. In vivo antimalarial activity was assessed using the 4-day suppressive antimalarial assay. Mice were infected by injection via tail vein with 2 × 10⁷ erythrocytes infected with Plasmodium berghei ANKA. Extracts were administered orally, once daily, for a total of four daily doses from the day of infection. Chloroquine (10 mg/kg/day) and solvent (5 mL/kg/day) were used as positive and negative controls, respectively. The extracts of C. bonducella, E. schliebenii, H. pubescens, and P. nummulariifolius exhibited dose-dependent suppression of parasite growth in vivo in mice, with the highest suppression being by C. bonducella extract. While each of the plant extracts has potential to yield useful antimalarial compounds, the dichloromethane root extract of C. bonducella seems to be the most promising for isolation of active antimalarial compound(s). In vivo antimalarial activity presented in this study supports traditional uses of C. bonducella roots, E. schliebenii stem barks, H. pubescens roots, and P. nummulariifolius for treatment of malaria.

Phyllanthus amarus: ethnomedicinal uses, phytochemistry and pharmacology: a review

ETHNOPHARMACOLOGICAL RELEVANCE

Phyllanthus amarus Schum. & Thonn. belongs to the family Euphorbiaceae is a small herb well known for its medicinal properties and widely used worldwide. P. amarus is an important plant of Indian Ayurvedic system of medicine which is used in the problems of stomach, genitourinary system, liver, kidney and spleen. It is bitter, astringent, stomachic, diuretic, febrifuge and antiseptic. The whole plant is used in gonorrhea, menorrhagia and other genital affections. It is useful in gastropathy, diarrhoea, dysentery, intermittent fevers, ophthalmopathy, scabies, ulcers and wounds.

MATERIALS AND METHODS

The present review covers a literature across from 1980 to 2011. Some information collected from traditional Ayurvedic texts and published literature on ethanomedicinal uses of Phyllanthus amarus in different countries worldwide.

RESULTS

Phytochemical studies have shown the presence of many valuable compounds such as lignans, flavonoids, hydrolysable tannins (ellagitannins), polyphenols, triterpenes, sterols and alkaloids. The extracts and the compounds isolated from P. amarus show a wide spectrum of pharmacological activities including antiviral, antibacterial, antiplasmodial, anti-inflammatory, antimalarial, antimicrobial, anticancer, antidiabetic, hypolipidemic, antioxidant, hepatoprotective nephroprotective and diurectic properties.

CONCLUSION

The present review summarizes information concerning the morphology, ecology, ethnopharmacology, phytochemistry, biological activities, clinical applications and toxicological reports of P. amarus. This review aims at gathering the research work undertaken till date on this plant in order to provide sufficient baseline information for future works and commercial exploitation.