In Vivo Antimalarial Activity of the Solvent Fractions of Fruit Rind and Root of Carica papaya Linn (Caricaceae) against Plasmodium berghei in Mice

Anti-malarial and haematological evaluation of the ethanolic, ethyl acetate and aqueous fractions of Chromolaena odorata

Malaria is a global health challenge with endemicity in sub-Saharan Africa, where there are multiple drug-resistant strains and limited access to modern health care facilities, especially in rural areas. Studies indicate that African traditional medicine could make a substantial contribution to the reduction of malaria-related deaths and achievement of universal health coverage (UHC), particularly in these regions. Thus, this study evaluated the curative antimalarial effects of Chromolaena odorata leaf extract using mouse model. Forty-five (45) albino mice weighing between 18 and 22 g were grouped into nine groups of 5 animals each. Animals in groups 2-9 were infected with the chloroquine-resistant strain of Plasmodium berghei, while animals in groups 3-9 were subsequently treated with 10 mg/kg chloroquine, a combination of 1.4 mg/kg artemether and 8.75 mg/kg lumefantrine (Coartem), and varying concentrations of the fraction from the aqueous leaf extract of C. odorata at day 3 post-infection. The findings from this study indicate that treatment with 400 mg/kg of the ethanolic fraction of the crude extract resulted in a significant decrease in parasite load (97.6%), which was comparable to the activities of the conventional drugs chloroquine (98.6%) and Coartem (98.8%). The ethyl acetate and ethanolic fractions at 400 mg/kg also ameliorated the significant alterations in the red blood cells, white blood cells, and platelets of the infected animals. The high antimalarial activity displayed by the ethanolic fraction could be due to the presence of quercetin and kaempferol, as detected by high performance liquid chromatography (HPLC) analysis. The findings suggest that the fractions from C. odorata could serve as an alternative source of malaria therapy, particularly in sub-Saharan Africa.

Potential Plant-Based New Antiplasmodial Agent Used in Papua Island, Indonesia

Resistance to antimalarial medicine remains a threat to the global effort for malaria eradication. The World Health Organization recently reported that artemisinin partial resistance, which was defined as delayed parasite clearance, was detected in Southeast Asia, particularly in the Greater Mekong subregion, and in Africa, particularly in Rwanda and Uganda. Therefore, the discovery of a potential new drug is important to overcome emerging drug resistance. Natural products have played an important role in drug development over the centuries, including the development of antimalarial drugs, with most of it influenced by traditional use. Recent research on traditional medicine used as an antimalarial treatment on Papua Island, Indonesia, reported that 72 plant species have been used as traditional medicine, with Alstonia scholaris, Carica papaya, Andrographis paniculata, and Physalis minima as the most frequently used medicinal plants. This review aimed to highlight the current research status of these plants for potential novel antiplasmodial development. In conclusion, A. paniculata has the highest potential to be developed as an antiplasmodial, and its extract and known bioactive isolate andrographolide posed strong activity both in vitro and in vivo. A. scholaris and C. papaya also have the potential to be further investigated as both have good potential for their antiplasmodial activities in vivo. However, P. minima is a less studied medicinal plant; nevertheless, it opens the opportunity to explore the potential of this plant.

Antimalarial activity of solvent fractions of a leaf of Eucalyptus globulus labill against Plasmodium berghei infected mice

Introduction

The leaf of Eucalyptus globulus is commonly used in the traditional management of malaria. However, the efficacy of solvent fractions are didn’t study yet scientifically. Thus, this study aimed to investigate the antimalarial efficacy of the solvent fractions of the leaf of Eucalyptus globulus in mice against P.berghei.

Methods

The antimalarial activity of the fractions was tested in a 4-day suppressive test, Rane’s test, and prophylactic test models within P.berghei infected mice. The results were analyzed using a one-way analysis of variance (ANOVA) followed by a post hoc Tukey’s test in version 20 SPSS.

Results

All fractions at all test doses in the three test models suppressed parasitemia (p < 0.001) compared to the negative controls. In addition, the CF and EA at all three test doses and the AF at 400 mg/kg in three antimalarial test models showed 50% and above parasitemia suppression. In compliance with this, all fractions at all test doses in all test models prolonged the mean survival time of the mice greater than 12 days, except the AF at a lower dose. All fractions at 400 mg/kg in the three test models prevented (p < 0.001) loss of body weight and rectal temperature compared to the negative controls. Furthermore, all fractions in all test models and doses prevented packed cell volume reduction (p < 0.05 to p < 0.001) compared to the negative controls..

Conclusion

The findings of this study showed that CF and EAF had greater antimalarial activity compared to AF. This could be attributed to the presence of few phytochemicals in the AF in contrast to the CF and EAF. Overall, the results of this study further support the in vitro antimalarial activity study and the traditional use of the leaf in the management of malaria.

In vivo antiplasmodial activities and acute toxicity assessment of two plant cocktail extracts commonly used among Southwestern Nigerians

Discovering and developing the desired antimalarials continue to be a necessity especially due to treatment failures, drug resistance, limited availability and affordability of antimalarial drugs and costs especially in poor malarial endemic countries. This study investigated the efficacies of two plant cocktails; CtA and CtB, selected based on their traditional usage. Efficacies of the cocktail extracts, chloroquine and pyrimethamine against Plasmodium berghei berghei were evaluated in mice using the suppressive, curative and prophylactic test models, after oral and intraperitoneal acute toxicity determination of the plant cocktails in accordance with Lorke's method. Data was analyzed using SPSS software version 23.0 with level of significance set at P < 0.05. The median lethal dose was determined to be higher than 5000 mg/kg body weight orally for both CtA and CtB; and 316.23 mg/kg body weight intraperitoneally for CtA. Each cocktail exhibited high dose dependent Plasmodium berghei berghei inhibition which was 96.95% and 99.13% in the CtA800 mg/kg and CtB800 mg/kg doses in the curative groups respectively, 96.46% and 78.62% for CtA800mg/kg and CtB800mg/kg doses in the suppressive groups respectively, as well as 65.05% and 88.80% for CtA800mg/kg and CtB800mg/kg doses in the prophylactic groups respectively. Throughout the observation periods, the standard drugs, chloroquine phosphate and pyrimethamine maintained higher inhibitions up to 100%. These findings demonstrate that CtA and CtB possess good antimalarial abilities and calls for their development and standardization as effective and readily available antimalarial options. The acute toxicity results obtained underscore the importance of obtaining information on toxicities of medicinal plant remedies before their administration in both humans and animals.

Antimalarial Activity of Hydromethanolic Crude Extract and Chloroform Fraction of Brucea antidysenterica Leaves in Plasmodium berghei-Infected Mice

Background

Different parts of Brucea antidysenterica are used in traditional and alternative medicine in Ethiopia for the treatment of different health problems including malaria and have good in vitro antimalarial activity. However, no in vivo study was conducted to substantiate the claim. Our study planned to determine the antimalarial effect of B. antidysenterica extract.

Methods

Swiss albino mice (6–8 weeks old, 20–28 g) were inoculated with Plasmodium berghei. Different doses of both hydromethanolic extract and chloroform fraction were orally given at 100, 200, and 400 mg/kg/day.

Results

The parasitemia suppression percent of hydromethanolic crude extract and chloroform fraction in chemosuppressive tests ranged between 33.48 and 75.93% and 38.32 and 76.64%, respectively. The hydromethanolic crude extract and chloroform fraction exhibited the curative effect of 46.75–70.91% and 50.30–80.06% parasitemia suppression, respectively (p < 0.001), compared with negative control.

Conclusion

From our study, it is concluded that the hydromethanolic crude extract and chloroform fraction of B. antidysenterica leaves showed promising antiplasmodial effects against Plasmodium berghei. This upholds the folkloric use of B. antidysenterica leaves and the thought of as a possible source to develop new antimalarial agents.

Evaluation of the Antimalarial Activity of Crude Extract of Eucalyptus globulus Labill. Leaf against Plasmodium berghei in Mice

Introduction

Traditional medicinal plants are used as a common source of developing new and effective antimalarial drugs. E. globulus leaf has been used in the traditional management of malaria in different countries, including Ethiopia. However, there is no in vivo study done on the antimalarial activity of the plant. Thus, this study aimed to evaluate the antimalarial activity of crude extract of E. globulus Labill. leaf in P. berghei-infected mice.

Method

The fresh leaves of E. globulus were collected, washed, air-dried, and made as coarse powder. Either sex of mice aged 6 to 8 weeks was used in the experiment. The antimalarial activity of the crude extract was tested in four-day suppressive, curative (Rane's), and prophylactic (repository) tests. The parameters like level of parasitemia, packed cell volume, body weight, rectal temperature, and mean survival time were recorded. The analysis of the data was done with SPSS version 20 with a 95% confidence interval in one-way ANOVA followed by Tukey's post hoc test.

Results

In all three antimalarial test models, the extract of leaf of E. globulus at all three doses suppressed the level of parasitemia significantly (p < 0.001), increased survival time (p < 0.05 to p < 0.001), and prevented a decrease in body weight as compared to the negative control. The middle and large doses of the extract also decreased loss of body temperature (p < 0.05 to p < 0.001) compared to the negative control. Reduction of packed cell volume was prevented within the three test doses of the extract in both curative and prophylactic tests and middle and large doses in the 4-day suppressive test compared to the negative control.

Conclusion

The crude extract of the plant showed promising antimalarial activity. This supports the traditional use and the in vitro test result of the plant.

In Vivo Antimalarial Activity and Toxicity Study of Extracts of Tagetes erecta L. and Synedrella nodiflora (L.) Gaertn. from the Asteraceae Family

Objective

To investigate the antimalarial effects and toxicity of the extracts of the flowers of Tagetes erecta L. and the leaves of Synedrella nodiflora (L.) Gaertn. in a mouse model.

Methods

To determine the in vivo antimalarial activity of the extracts, mice were intraperitoneally injected with the Plasmodium berghei ANKA strain and then administered T. erecta or S. nodiflora extract daily for 4 days. Parasitemia was observed by light microscopy. For the detection of acute toxicity, the mice received a single dose of T. erecta or S. nodiflora extract and were observed for 14 days. Biochemical parameters of liver and kidney function and the histopathology of liver and kidney tissues of the acute toxicity group were then examined.

Results

T. erecta and S. nodiflora crude extracts at a dose of 600 mg/kg body weight significantly suppressed parasitemia in malaria-infected mice by 65.65% and 62.65%, respectively. Mice treated with 400 mg/kg T. erecta and S. nodiflora crude extracts showed 50.82% and 57.67% suppression, and mice treated with 200 mg/kg displayed 26.33% and 38.57% suppression, respectively. Additionally, no symptoms of acute toxicity were observed in the T. erecta- and S. nodiflora-treated groups. Moreover, no significant alterations in the biochemical parameters of liver and kidney function and no histological changes in the liver or kidney tissues were observed.

Conclusions

This study revealed that both T. erecta and S. nodiflora extracts have antimalarial properties in vivo with less toxic effects. Further studies are needed to elucidate the mechanisms of the active compounds from both plants.

Anti-Oxidant Potential and Antimalarial Effects of Acanthus polystachyus Delile (Acanthaceae) Against Plasmodium berghei: Evidence for in vivo Antimalarial Activity

BACKGROUND

Malaria is among the most devastating and widespread tropical parasitic diseases which is more prevalent in developing countries. Acanthus polystachyus (Acanthaceae) leaves are traditionally used for the treatment of malaria in Ethiopia. This study aimed to investigate the in vivo antimalarial and in vitro antioxidant activity of the leaves extract of Acanthus polystachyus.

MATERIALS AND METHODS

The leaves part of A. polystachyus were extracted using 80% methanol. The antioxidant effect of Acanthus polystachyus extract was evaluated by using (DPPH) diphenyl-2-picrylhydrazyl assay model. To evaluate the antimalarial effect of the A. polystachyus extract, Plasmodium berghei ANKA strain (chloroquine sensitive) was used to infect the mice in three different experimental protocol: suppressive, curative, and prophylactic test models.

RESULTS

The leaves extract of Acanthus polystachyus significantly (P<0.05-0.0001) suppressed the parasitemia in all experimental protocol. The extract exhibited a chemosupression of 27.64%, 33.67% and 49.25% in 4-day suppressive test; 33.76%, 39.24% and 53.59% in curative test, and 25%, 32.84% and 50% in prophylactic tests at dose of 100, 200, and 400mg/kg, respectively. The extract also extended the mean survival time, prevented the bodyweight loss and body temperature drop, and packed cell volume significantly (P<0.05) as compared to the negative control. Dose-dependent antioxidant activity was shown by the leaf extract of A. polystachyus with an IC50 value of 9.37µg/mL.

CONCLUSION

The current finding showed that the leaves extract of Acanthus polystachyus has revealed promising antimalarial effects. Thus, this finding supports the traditional use of A. polystachyus for the treatment of malaria.

In vivo studies on the biochemical indices of Plasmodium berghei infected mice treated with Alstonia boonei leaf and root extracts

BACKGROUND

A study on the biochemical indices of albino mice infected with Plasmodium berghei and treated with Alstonia boonei aqueous and ethanolic extracts was undertaken.

METHODS

216 males mice were randomly assigned to six treatment groups each containing six mice for both aqueous and ethanolic extracts experiments. P. berghei NK-65 was inoculated into the mice intraperitoneally and establishment of infection confirmed. Administration of extracts of was done after phytochemical and acute toxicity tests at varying concentrations, for both suppressive and curative tests. Blood samples collected by ocular puncturing were examined for the biochemical indices; ALT, AST, ALP, creatinine and total protein using the standard procedures.

RESULTS

A. boonei extracts suppression of P. berghei in mice was comparable to the standard drug. Significantly higher (p<0.05) recovery of mice treated with A. boonei extracts was observed. The biochemical indices examined all had significantly (p<0.05) increased concentration after 7 days post-infection, except for total protein concentration which had no significant increase or decrease due to A. boonei extracts administration.

CONCLUSION

The antiplasmodial potentials of A. boonei leaf and root extracts were dosage and duration-dependent, and have demonstrated satisfactory normalization of altered biochemical indices due to malaria.

In Vivo Antiplasmodial Activity of Different Solvent Extracts of Myrianthus libericus Stem Bark and Its Constituents in Plasmodium berghei-Infected Mice

The emergence and resurgence of P. falciparum resistance to generations of antimalarial drugs have prompted the search for new, effective, and safe antimalarial agents. This study aimed at investigating the in vivo antiplasmodial activity of the 70% hydroethanolic extract and constituents of the stem bark of Myrianthus libericus based on its ethnomedicinal use as an antimalarial agent. The antiplasmodial activity was assessed in Swiss albino mice employing the 4-day suppressive and Rane's tests. MLB significantly (p < 0.0001) suppressed parasitaemia by 52.26%, 65.40%, and 77.11% at 50, 100, and 200 mg·kg⁻¹ doses, respectively, in the 4-day suppressive test. In Rane's test, the highest parasitaemia suppression of 72.50% was recorded at a dose of 200 mg·kg⁻¹ of the extract. Fractionation of the bioactive ethyl acetate fraction by solvent-solvent partitioning and column chromatography led to the isolation of friedelan-3-one and stigmasterol being reported for the first time from this species. The compounds demonstrated remarkable antiplasmodial activity by suppressing parasitaemia by 65–72% in the suppressive test and 61–70% in the curative test at doses of 10–30 mg·kg⁻¹. Both the extract and the isolated compounds significantly prolonged the survival time of infected mice and averted the cardinal signs associated with P. berghei-induced malaria including weight loss, hypothermia, and haemolysis. The results obtained confirm the prospect of M. libericus as an important source of new antimalarial compounds and justifies its folkloric use as an antimalarial agent.

Natural Products as Sources of Antimalarial Drugs: Ethnobotanical and Ethnopharmacological Studies

MATERIALS AND METHODS

For this study, relevant information was procured from the inhabitants via a structured questionnaire to procure the general knowledge of antimalarial medicinal plants. Results and Discussion. A total of 90 interviewees (44 men and 46 women) were involved in this survey. A total of 59 medicinal species were identified, which were dispersed in 33 families (Asteraceae (6), Apocynaceae (5), Anacardiaceae, Annonaceae, Fabaceae, Malvaceae, Meliaceae, Poaceae, and Rubiaceae (3 each), Phyllanthaceae (2)) totaling 49% of the cited species. The most cited plants are Azadirachta indica (42), Mangifera indica (38), Carica papaya (28), Cymbopogon citratus (27), Cassia fistula (15), Morinda lucida (14), Anacardium occidentale and Vernonia amygdalina (13 each), Helianthus annuus (11), Enantia chlorantha (10), and Moringa oleifera (9) A total of 105 citations were recorded for the plant parts used (leaf (46), bark (17), fruits (9), root (9), latex (11), stem (11), and inflorescence (2)) while decoction (59%), maceration (25%), infusion (9%), and exudation (7%) were the methods of preparation. Use Values (UVs) of 0.47 to 0.11 were recorded for the frequently used antimalarial plants. The Efficiency Levels (ELs) of 11 different medicinal plants stated by the respondents were Azadirachta indica, Cassia fistula and Morinda lucida (12), Chromolaena odorata (10), Mangifera indica, Enantia chlorantha and Helianthus annuus (8), Cymbopogon citratus (7), Gossypium arboretum (4), Landolphia dulcis (3), and Aloe vera (2) Cocos nucifera, Curcuma longa, Forkia biglobosa, and Musa acuminate are mentioned for the first time in the study area with little or no reported antiplasmodial activities.

CONCLUSION

The study appraised the commonly used antimalarial plants in the study areas. Therefore, commitment to scientifically explore the bioactive compounds, antimalarial potential and toxicological profile of these plants is inevitable as they could lead to novel natural products for effective malaria therapy.

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.

Antimalarial Activity of Plant Metabolites

Malaria, as a major global health problem, continues to affect a large number of people each year, especially those in developing countries. Effective drug discovery is still one of the main efforts to control malaria. As natural products are still considered as a key source for discovery and development of therapeutic agents, we have evaluated more than 2000 plant extracts against Plasmodium falciparum. As a result, we discovered dozens of plant leads that displayed antimalarial activity. Our phytochemical study of some of these plant extracts led to the identification of several potent antimalarial compounds. The prior comprehensive review article entitled “Antimalarial activity of plant metabolites” by Schwikkard and Van Heerden (2002) reported structures of plant-derived compounds with antiplasmodial activity and covered literature up to the year 2000. As a continuation of this effort, the present review covers the antimalarial compounds isolated from plants, including marine plants, reported in the literature from 2001 to the end of 2017. During the span of the last 17 years, 175 antiplasmodial compounds were discovered from plants. These active compounds are organized in our review article according to their plant families. In addition, we also include ethnobotanical information of the antimalarial plants discussed.