Isolated compounds are evaluated for their biological activities using in-house bioassays. The bioassays include in vitro inhibition of platelet aggregation in human whole blood, inhibition of platelet activating factor (PAF) binding to receptor in vitro, inhibition of LDL peroxidation, immunomodulatory effects-chemotactic activity, CD18 suface expression, phytocytic activity and respiratory burst activity, antimicrobial and antifungal activities, insecticidal activities, larvicidal, adulticidal and repellent activities. Inhibitory effects on the production and secretion of prostaglandin E2 (PGE2), thromboxane B2 (TXB2) and cytokines as anti-inflammatory mediators are also investigated. The effects of plant extracts on the central nervous system (CNS) have been studied using cell culture and animal behavioral model. Novel object recognition determines the effects of plant extracts on non-spatial memory and Conditioned Place Peference (CPP) is utilised to identify plant extracts with putative addictive properties.