IN VITRO ANTIOXIDANT AND FREE SCAVENGING ACTIVITIES OF EXTRACTS AND SOLUBLE FRACTIONS, ACUTE AND SUBACUTE TOXICITY OF AQUEOUS EXTRACT FROM CYMBOPOGON CITRATUS (DC.) STAPF (POACEAE) AND LIPPIA MULTIFOLIA MOLDENKE (VERBENACEAE) LEAVES

Musimbele N., Mpona M. M., Mondo M., Kikweta M. C. and Cimanga K. R.*

ABSTRACT

The present study was initiated in the evaluation of antioxidant activity of extracts and soluble fractions from Cymbopogon citraus and Lippia multifolia leaves in vitro against fivr selected reactive oxygen species, (ROS) and acute and subacute toxicity of aqueous extract from both selected medicinal plants in vivo. Results revealed that aqueous and methanol 80% extracts from C. citratus and L. multifolia leaves exhibited pronounced antioxidant activity against all selected ROS with IC50 values < 10 μg/ml. Their respective chloroform, ethylacetate, n-butanol and residual soluble fractions also exhibited pronounced antioxidant activity by producing IC50 values < 10 μg/ml against all selected ROS. In acute and subacute toxicity, both aqueous extracts had no significant influence on the levels of hematological and biochemical parameters of treated rats since all reported values were found to be in acceptable physiological limits. In addition, they did not cause mortality of treated rats since their LD50 were estimated to be greater than 5000 mg/kg bw and did not significantly modify the vital organ weights and electrolytes levels of treated Wistar rats. Both aqueous extracts form C. citratus and L. multifolia were considered practically non-toxic per os supporting their use for a lo time without the occurring of side effects.

Keywords: Cymbopogon citratus, Poaceae, Lippia multifolia, Vernenaceae, Extracts, Soluble fractions, antioxidant activity, Acute and Subacute toxicity.