Life Science Journal 2014;11(9) http://www.lifesciencesite.com 149 The Antioxidant Activity of Desert Rose (Adenium arabicum) Leaves On Hyper Cholesterolemic Male Rats Abdulbasit I. Al-Sieni Biochemistry Department, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia aalsieni@kau.edu.sa Abstract: The leaf powder of desert rose (Adenium arabicum) was supplemented orally in the diet to hypercholesterolemic male Albino rats for 8 weeks to test its antioxidant activity and its effect on lipid peroxidation. Eighteen male rats weighing 180-200 gm were divided into three groups. The first group is untreated control group fed normal diet, the second group was fed 2% cholesterol in diet to induce hypercholesterolemia (positive control group), and the third group was fed 2% cholesterol (to induce hypercholesterolemia) and treated with 500 mg/kg body weight rose leaf powder for 8 weeks. The positive control group showed a significant increase in lipid peroxide and a significant decrease in antioxidant enzymes; glutathione reduced (GSH), serum glutathione reductase (GR) and serum superoxide dismutase (SOD) activity in the serum and tissue homogenate. Moreover, histopathology of liver and kidney in the positive control group showed histopathological changes compared with the negative control ones. Treating the hypercholesterlemic rats with desert rose leaves increased the antioxidant enzyme activity and decreased lipid peroxide. In addition, the histopathology of the studied organs was also recovered and seemed normal after desert rose treatment. In conclusion, desert rose leaves have an important anti-oxidant activity, decreased lipid peroxidation and improved the tissues of the kidney and liver of hypercholesterolemic rats under study. [Abdulbasit I. Al-Sieni. The Antioxidant Activity of Desert Rose (Adenium arabicum) Leaves In Hyper Cholesterolemic Male Rats. Life Sci J 2014;11(9):149-158]. (ISSN:1097-8135). http://www.lifesciencesite.com . 21 Key words: antioxidant, lipid peroxide, rats, desert rose, histopathology 1. Introduction Adenium arabicum Forssk. (desert rose, giant desert rose, impala lily, Adnah) belongs to the family Apocyanaceae. Adenium arabicum; is an endemic, rare, on the mountains of southern region of Saudi Arabia (Rahman et al., 2004). It is poisonous and toxic and has some medicinal properties; the sap and bark are used in bones dislocations, painful joints, wounds and skin infections (Mossa et al., 1987 and Shahina, 1994). The increase of lipid parameters has been shown to be a strong risk factor for coronary heart diseases in many populations (Makni et al., 2008). In addition, free radicals induced oxidation of lipids is controlled by a wide spectrum of enzymatic antioxidants and non-enzymatic antioxidants such as superoxide dismutase (SOD), glutathione reductase, and glutathione peroxides (GSHPx), vitamin E and (Valko et al., 2007). In addition, some non-enzymatic antioxidants such as vitamins C, vitamin E, carotenoids and phenolic compounds may be important in the pathogenesis of oxidative stress related disorders (Southom and Powis, 1988 and Valko et al., 2007). It was also found that nitric oxide (NO) is a crucial modulator of vascular damage (Rathod et al., 2011). Napoli et al. (2001) reported that NO has intracellular effects that lead to vasorelaxation, endothelial regeneration, reduction of oxidative mechanism, inhibit leukocyte chemotaxis and platelet adhesion. In a study of the antioxidant activity of Adenium obesum flowers crude extract, Palé et al. (2004) reported that the antioxidative activities of the crude extract was similar to that of ascorbic acid used as reference. The objective of the current study was testing the efficiency of desert rose leaves as an antioxidant and lowering lipid peroxidation in hypercholesterolemic in serum and tissue homogenate of liver and kidney in male wistar albino rats. 2. Materials and Methods The desert rose leaves The desert rose leaves were collected from a local desert rose tree identified as Adenium arabicum Forssk. These leaves were washed, air dried, milled by mixer and then mixed to the diet in a ratio of 500 mg/kg body weight. Basal lipid rich diet: The basal diet consisted of the following: 16% casein, 10% corn oil, 4% N.N cellulose, 4% salt mixture, 1% vitamin mixture, 0.2% choline chloride, 0.2% DL. methionine and 64.5% corn starch. Animals and housing conditions Eighteen male albino wister rats “Rattas rattas” weighing 180-200g were obtained from Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia. Rats were housed six per polycarbonate cage. Cages, bedding, and glass water bottles (equipped with stainless steel sipper tubes) were replaced twice