Journal of Clinical & Experimental Pharmacology

Abstract

Antimalarial Potential of the Leaf Exudate of Aloe macrocarpa Todaro and its Major Constituents against Plasmodium berghei

Yitagesu Tewabe and Solomon Assefa

Background: Aloe macrocarpa Todaro is one of the Aloe species in Ethiopia where its leaf exudate is traditionally used for the treatment of various ailments, including malaria.
Methods: Two pure compounds namely aloin and aloinoside were isolated from the leaf exudate. Further oxidative hydrolysis yielded another compound (aloe-emodin). Four-day suppressive test was employed to evaluate the antimalarial potential of the leaf exudates and isolated compounds as well as aloe-emodin against mice infected with Plasmodium berghei.
Results: The leaf exudate of A. macrocarpa showed significant chemosuppression of P. berghei at all dose levels tested compared to the negative control group. At a dose of 400 mg/kg, the leaf exudate of A. macrocarpa, the isolated aloin as well as the semi-synthetic derivative (aloe-emodin) suppressed parasite growth by 74.3, 64.2 and 94.7%, respectively, which was statistically significant (p<0.01) compared to the negative control group. Moreover, maximal dose of aloinoside (400 mg) exhibited similar chemosuppression effect (100%) and comparable weight loss prevention with chloroquine.
Conclusion: The present study indicated that aloin, aloinoside and aloe-emodin are promising antimalarial principles of A. macrocarpa, and further support the traditionally claimed use of the plant against malaria.