Protective effect of luteolin on DNA damage of peripheral blood lymphocytes of isoproterenol-induced heart failure rats / 西安交通大学学报(医学版)

ABSTRACT

Objective: To explore the effects of luteolin on DNA damage of peripheral blood lymphocytes of isoproterenol-induced heart failure rats by using comet assay and micronucleus assay. Methods: Male SD rats aged 6-7 weeks were randomly divided into heart failure group (HF, n=10) and control group (Ctrl, n=10). The heart failure model was established through intraperitoneal injection of isoproterenol (50 mg/kg) for 10 consecutive days. Echocardiography was conducted to confirm HF model construction. Blood was taken from the abdominal aorta from rats in both groups using EDTA-anticoagulate tubes. Peripheral blood lymphocytes were separated bylymphocyte isolation kit within two hours after the blood was taken. Comet assay was carried out to test the short-run damage of DNA. Then those lymphocytes were treated with 5, 10, 20, and 50 μmol/L of luteolin and comet assay was carried out again after 30 min to test DNA damage. The lymphocytes were treated with 50 μmol/L of luteolin to culture new peripheral blood for micronucleus assay. Optic microscopy detected long-term DNA damage of the cells. Results: Compared with those in Ctrl group, the mean ejection fraction of left ventricle (EF%) of HF group was decreased; left ventricular fraction shortening, left ventricular end-systolic diameter, and left ventricular end-diastolic diameter significantly increased. These indicated that the heart failure model was established successfully. Compared with Ctrl group, the ratio of Tail DNA in HF group increased (P<0.05). Compared with that in HF group, Tail DNA decreased in 50 μmol/L luteolin-treated HF group (P<0.05). The micronuleus assay results were in accordance with comet assay results. Basically, the number of micronucleus in 1000 cells increased in HF group compared with Ctrl group, but decreased when treated with 50 μmol/L of luteolin. Conclusion: Luteolin can significantly reduce DNA damage on peripheral blood lymphocytes of HF rats.