In this study, the phenolic compounds of Allium tuncelianum water extracts were determined by LC-MS / MS and HPLC. Wistar albino female rats were used to determine the effect on antioxidant enzyme levels. Five groups of female rats, each containing eight individuals were studied. The first group was control without any treatments. The second group was treated 7,12-DMBA, third, and fourth groups were treated with DMBA + 250, and 500 mg/kg/day of Allium tuncelianum water extracts, fifth group was treated DMBA+ 200 mg/kg of E vitamin (twice a week) for one month, respectively. The rats were feed for one month, slaughtered afterwards and the cardiac tissue was taken for the experiments. Catalase (CAT) and superoxide dismutase (SOD), Malondialdehide (MDA) and Glutatyon (GSH) parameters, which are antioxidant and oxidative stress markers on the heart tissue of Allium tuncelianum water extract were investigated. Result of this study indicated that Allium tuncelianum water extract was poor in phenolic compound diversity but had a very rich content in terms of some other components including pyrocatechol, kainic acid, fumaric acid and malic acid. Antioxidant enzymes (CAT, SOD) levels in heart tissue decreased significantly (p < 0.05) in the oxidative stress groups compared to the control groups (p < 0.05) and Allium tuncelianum water extract showed a decrease in CAT enzyme activity and an increase in SOD enzyme activity relative to the group given 7,12-DMBA. There was also a decrease in MDA levels compared to the 7,12-DMBA group. It can be concluded that Allium tuncelianum water extract can prevent oxidative stress by increasing SOD enzyme activity and reducing MDA levels.