ABSTRACT

Plants contain a wide variety of free radical scavenging molecules, such as phenolics, flavonoids and endogenous metabolites. These plant-derived antioxidants have been shown to function as single and triplet oxygen quenchers, peroxide decomposers, enzyme inhibitors and synergists. Breynia retusa is commonly known as the cup saucer plant and belongs to the family Euphorbiaceae. Moreover, the knowledge and application of such potential antioxidant activity in reducing oxidative stresses in vivo has prompted many investigators to search for potent and cost-effective antioxidants from various plant sources. The DPPH radical was used to measure the free radical scavenging activity of plant extracts by the method of Blois. Soxhlet extraction is a standard method for the extraction of bioactive compounds from plant sources. Polyphenols are the major plant compounds with antioxidant activity. This activity is believed to be mainly due to their redox properties, which can play an important role in adsorbing and neutralizing free radicals, quenching singlet and triplet oxygen or decomposing peroxides.