Abstract

We have evaluated the phytochemical and bioactive nature of the leaves ofMallotus peltatus (Geist.) Muell. Arg. var acuminatus and Alstonia macrophyllaWall ex A. DC, the two major ethno medicines of the Onge, Nicobarese and other tribes of Andaman and Nicobar Islands, on the Bay of Bengal, India. Three major compounds were isolated from the polar fractions of the methanol extracts of Alstonia macrophylla leaf namely b-sitosterol (fraction A), ursolic acid (fraction B) and b-sitosterol b-D-glucoside (fraction C), along with a minor fraction containing alkaloid and fatty acids. On the other hand polar fractions of methanol extract of Mallotus peltatus leaf yielded two major compounds, ursolic acid (fraction A) and b-sitosterol (fraction B), along with a minor fraction containing fatty acids. The earlier studies reveal that both the extracts have antibacterial, antiinflammatory, antipyretic and analgesic activities, but the present study showed that the activities are due to fractions A and B of both the plants. Moreover, the extracts of both the plants had significant dose dependent antiinflammatory and antioxidant activity at nontoxic concentrations. It can be thus concluded that the terpenoid and β-sitosterol, along with other minor constituent of the bioactive parts had a dose dependent therapeutic efficacy, justifying their use. However, further study can help to elucidate their mechanism of action.

Key words: Ethnomedicine, A. macrophylla, M. peltatus, Pharmacology and phytochemistry, antibacterial, antioxidant, antiinflammatory activity.