Free Radical Scavenging Activity of Some Plants Available in Malaysia

The present study was carried out to determine the free radical scavenging properties of some plants, found in Malaysia. The air-dried leaves of each plant (20 g) were soaked in distilled water (1:20; w/v) for 72 h at room temperature. Collected supernatants were tested for free radical scavenging activity against the DPPH and superoxide anion radical scavenging assays. All extracts were found to show remarkable antioxidant activity in both assays with the percentage inhibition (%) of 94–99% and 83–100%, respectively. Phytochemicals screening of all plants demonstrated the presence of flavonoids, saponins, triterpenes and steroids, but not alkaloids. Tannins were detected only in the leaves of M. calabura , D. linearis , M. malabathricum . The ability to scavenge free radicals indicates these plants potential as new sources of antioxidant agents, and the activity seen could be attributed to the synergistic effect of various bioactive compounds presence in those extracts, particularly of the flavonoids type. Further study has been designed in our laboratory to isolate and identify the bioactive compounds responsible for the observed antioxidant activity.