10.22376/ijpbs.2019.10.1.p1-12 Volume 12 issue 4 October - December The study was carried out to determine the lessThan i greaterThan in vivo lessThan /i greaterThan lessThan i greaterThan lessThan /i greaterThan antioxidant and lipid peroxidation effect of ethanolic extracts of whole plant of lessThan i greaterThan Ziziphus xylopyrus ( lessThan /i greaterThan family Rhamnaceae) lessThan i greaterThan . lessThan /i greaterThan High fat diet rats showed significantly (P lessThan 0.001) reduced levels of tissues enzymatic antioxidant and enhanced level of non enzymatic antioxidant (Glutathione). The level of thiobarbituric acid reactive substances (TBARS) are elevated in high fat diet (HFD) rats (group II) when compared with control group. Administration of ethanolic extract of lessThan i greaterThan Ziziphus xylopyrus lessThan /i greaterThan in high fat diet rats were showed significantly (p lessThan 0.001) increased levels of antioxidant enzymes such as Superoxide dismutase (SOD), Catalase (CAT), Glutathione peroxidase (GPx), Glutathione reductase (GR) and reduced the level of non enzymatic antioxidant. The ethanolic extract of lessThan i greaterThan Ziziphus xylopyrus lessThan /i greaterThan in high fat diet rats were found lowe concentration of hiobarbituric acid reactive substances (TBARS) when compared with high fat diet (HFD) rats (Group II). The ethanolic extract of lessThan i greaterThan Ziziphus xylopyrus lessThan /i greaterThan showed significant (p lessThan 0.001)??? result than that of other groups. Based on the results, we concluded that the ethanolic extract of lessThan i greaterThan Ziziphus xylopyrus lessThan /i greaterThan is a significant source of natural antioxidant, which might be helpful in preventing the progress of various oxidative stresses. The traditional uses of the different parts of the plant for the treatment of different ailments such as obesity, urinary troubles, diabetes, skin infections, fever, diarrhoea, insomnia, digestive, and liver disorders(not needed) . It also possesses anthelmintic, antimicrobial, antidepressant, analgesic and anti-inflammatory activities. The leaves contain quercetin. The fruits contain tannins, oleanolic acid,l-epicatechin, l-leucocyanidin and 3, 3, 4-tri-O-methyl-ellagic acid. The bark contains tannins, d-7, 3', 4'-trihydroxy flavan-3, 4-diol and oleanolic acid. The stem wood of the plant is reported to contain alkaloids (xylopyrine-A and B), triterpenoids and flavonoids. M. Prabhu, Sureshkumar R.B and G.Alagumanivasagam Antioxidants, high fat diet, thiobarbituric acid reactive substances, Glutathione reductase, Catalase, Glutathione peroxidase. 8-12