Evaluation of the use of Ocimum suave Willd. (Lamiaceae), Plectranthus barbatus Andrews (Lamiaceae) and Zanthoxylum chalybeum Engl. (Rutaceae) as antimalarial remedies in Kenyan folk medicine

• Published in: Journal of ethnopharmacology Vol. 178; pp. 266 - 271
• Main Authors: Kiraithe, Micheni N., Nguta, Joseph M., Mbaria, James M., Kiama, Stephen G.
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier Ireland Ltd 03.02.2016
• Subjects: Animals; Antimalarial; Antimalarials - chemistry; Antimalarials - pharmacology; Artemia - parasitology; Crude extract; Decapoda; Female; Kenya; Lamiaceae; Lamiaceae - chemistry; Malaria - drug therapy; Male; Medicinal plants; Medicine, African Traditional - methods; Mice; Ocimum; Ocimum - chemistry; Phytotherapy - methods; Plant Extracts - chemistry; Plant Extracts - pharmacology; Plant Leaves - chemistry; Plasmodium berghei; Plasmodium berghei - drug effects; Plasmodium falciparum; Plectranthus; Plectranthus - chemistry; Rutaceae; Rutaceae - chemistry; Swiss albino mice; Toxicity; Zanthoxylum; Zanthoxylum - chemistry; Swiss albino mice; Medicinal plants; Antimalarial; Plasmodium berghei; Crude extract; Toxicity
• ISSN: 0378-8741; 1872-7573
• DOI: 10.1016/j.jep.2015.12.013

Crude extracts from the leaves of Ocimum suave Willd (Lamiaceae) and the root barks of Plectranthus barbatus Andrews (Lamiaceae) and Zanthoxylum chalybeum Engl. (Rutaceae) were studied to ascertain the ethnopharmacological standing of their antimalarial usage in Kenyan folk medicine. Aqueous and Chloroform: Methanol (1:1) extracts of the plants were used in this study. Toxicity of the extracts was investigated by using brine shrimp lethality test and acute oral toxicity in mice. The antimalarial activity at a dose of 100mg/kg was screened in Swiss albino mice against chloroquine sensitive Plasmodium berghei (D6) using Peters 4-day suppressive test. Chloroquine, at a dosage rate of 20mg/kg was used as a reference drug. The extracts showed some signs of acute toxicity in the brine shrimp lethality test. However, no signs of toxicity were observed in the mice at a dose of 2000mg/kg of the crude extracts. The results revealed that all the tested crude extracts were safe. Z. chalybeum aqueous extract and P. barbatus organic extract showed chemosuppressive activities of 81.45% and 78.69%, respectively. This antimalarial activity was not significantly different from that of chloroquine (P<0.05). The findings suggest that the Kenyan folkloric medicinal application of these plants has a pharmacological basis. Bioactivity guided fractionation and isolation of bioactive molecules from the two species could lead to new hits against Plasmodiumfalciparum malaria. [Display omitted]