Evaluation of in vitro and in vivo Antiplasmodial Activity of the Leaf Latex of Aloe Weloensis (Aloaceae)

Abstract Background: Nature has gifted a variety of plants having potential effect against plasmodium parasites. The present study was aimed to determine in vitro and in vivo antimalarial activity of the leaf latex of Aloe weloensis.Methods: In vitro antimalarial activity of the leaf latex of A. weloensis was determined against 3D7 strain of P. falciparum. Antimalarial activity of the three doses the latex was evaluated in 4 day-suppressive and curative models against P. berghei infected mice. Antioxidant activity of the leaf latex of A. weloensis was assessed in 2,2- diphenyl 1- picrylhydrazine assay model. Results: Antioxidant activity of the latex was concentration dependent; the strongest inhibition was measured at 400 μg/mL (73.54%). The leaf latex of A. weloensis was demonstrated inhibitory activity against 3D7 malarial strain (IC50 = 9.14 μg/ml). Suppressive and curative effect of the latex was found to be dose dependent. Parasitemia reduction was significant (200 mg/kg, p<0.01, 400 and ,600 mg/kg, p<0.001) in 4-day suppressive test compared to vehicle control. Parasitemia level of the mice treated with 200, 400 and 600 mg/kg doses of the latex significantly (p<0.001) reduced with suppression of 36%, 58% and 64% respectively in curative test. Administration of the leaf latex of A. weloensis significantly (p<0.01) improved mean survival time, pack cell volume, rectal temperature and body weight of P. berghei infected mice. Conclusion: The finding showed that the leaf latex of Aloe weloensis endowed prominent antimalarial and antioxidant activities. The result can serve as a step towards the development of safe and effective herbal therapy against plasmodium parasites.