ABSTRACT
The purpose of this study is to evaluate the antioxidant activity of Thai Curcuma longa and Aegle marmelos, and their parasite suppressive effects on malaria infection in mouse model. The polyphenol content and antioxidant activities (Oxygen radical absorbance capacity (ORAC) and Ferric Reducing Antioxidant Power (FRAP)) were measured in crude extracts of Curcuma longa and Aegle marmelos. Seven-week old female ICR mice were divided into 5 groups randomly. First two groups served as control and placebo, the other 3 served as experimental groups with various concentrations; 20, 40 and 60 mg/kg, respectively. On day 0, 106 Plasmodium yoelii 17X (lethal) strain were inoculated to all mice. At day 1, placebo mice were given 30% ethanol. The latter 3 groups were treated with each concentration of each herb. Parasitemia was checked daily by tail snip bleed staining with Giemsa staining. Suppressive effects on day 4 were calculated. Student t-test was performed to display the difference among groups. Significantly different was justified at p <0.05. The antioxidant activities (both ORAC and FRAP) and polyphenol content of A. marmelos were higher than those of C. longa significantly. The suppressive effect on parasite in infected mice, there showed no effect of C. longa treatment, oppositely, at the doses of 20 and 40 mg/ kg body weigh of A. marmelos showed suppressive effect on infection by the parasite. In conclusion, a Thai traditional fruit, A. marmelos exhibited high antioxidant and antiplasmodial activities, this might be one of the candidates of the traditional plants for curing malaria.