Antioxidant Properties of the Ethyl Acetate Fraction of Intsia Palembanica (Merbau, Fabaceae)

Plants are playing an important role in maintaining human health and improving the quality of life. Since their ancestors, many people from developing countries have been using traditionally plant-derived products, especially from forests, to treat human and livestock diseases Rao et al. A few countries such as China, India, Thailand, Sri Lanka, Cuba, and a few others have sanctioned the official use of traditional of medicine in their healthcare programs Prajapati et al. [1]. Modern pharmacopoeia currently has about 25% of drugs obtained from plants and several others are synthetic analogues built on prototype compounds isolated from plants [2]. A study has been done on the Australian tropical forests on the pharmacological activities of 90 species of plants representing 19 families. 53 of the plant species examined indicated phytomedicinal potential for further investigation [3]. Most of the pharmacological effects of these plants are contributed to the presence of phenolic constituents which are broadly distributed in the plant kingdom. Many studies have found strong relationship between the presence of phenolic constituents (flavanoids, phenolic acids, diterpenes and tannins) in plants and their high antioxidant activities (Rice-Evans et al., 1995; Velioglu et al., 1998; Nakachi et al., 2000; Conforti et al., 2009). Some epidemiological studies have suggested an association between the consumption of phenolic-rich fruits and vegetables or beverages and the prevention of cardiovascular diseases and cancer [4-7]. These pathological conditions are connected with excessive free radical production that could also lead to various serious diseases such as neurodegenerative disorders, atherosclerosis, cataracts and inflammation (Aruoma, 1998; Liu and Stern, 1998; Babior and Andreoli 2000). Iron can induce lipid peroxidation by the Fenton reaction, and also increase lipid peroxidation by highly reactive hydroxyl radical generated from biological systems (Liochev, 1999). Numerous studies confirmed the ability of plant polyphenols to scavenge free radicals and chelate metal ions, established their potential act as chain-breaking antioxidants [8].