Investigation of antioxidative and cardioprotective effects of Viburnum opulus extract on isoprenaline-induced myocardial infarction in rats: A molecular evaluation

Myocardial infarction is a serious consequence of coronary artery disease. It occurs when the heart muscle is deficient in oxygen and nutrients. This process is caused by oxidative stress, overproduction of free radicals and reactive oxygen species and inadequate antioxidant defence mechanisms. The aim of this study was to investigate the antioxidative, anti-inflammatory and cardioprotective effects of Viburnum opulus(VO) extract in isoprenaline-induced myocardial infarction model. Forty-two male Wistar rats were included in the study. These rats were divided into 6 subgroups as Control, isoprenaline (ISO), 400 mg/kg VO(VO400), isoprenaline+100 mg/kg VO(ISO+VO100), isoprenaline+200 mg/kg VO(ISO+VO200), isoprenaline+400 mg/kg VO(ISO+VO400). Substances were administered to the groups for 30 days. Isoprenaline(100 mg/kg/day) was administered by subcutaneous injection on the last two days of the study (days 29 and 30). Rats were anaesthetised with 1.25 g/kg urethane 24 hours after the last administration. Electrocardiographic(ECG) recordings were taken for 2 minutes after anaesthesia. After ECG, blood sampling was performed by cardiac puncture method. SOD, CAT, GPx, MDA, Nrf2, HO-1, CK-MB, cTn-I, TNF-α and CRP levels were determined by ELISA method. The hearts were removed and stored in a suitable environment for histopathological evaluation. In the electrocardiographic evaluation, the mean R wave amplitude was found to be significantly lower in the ISO group than in the control and VO400 groups, but not significantly lower in the ISO+VO200 and ISO+VO400 groups, except in the ISO+VO100 group. Heart rate was higher in the ISO group except ISO+VO200 group. ST segment mean and T wave amplitude mean were statistically higher in the ISO group compared to the other groups except ISO+VO100 group. TNF-α, CRP, HO-1, CK-MB, cTn-I and MDA levels were found to be statistically lower in the VO group compared to the ISO group (p<0.05). On the contrary, Nrf2, CAT, GPx and SOD levels were statistically higher in the VO groups(p<0.05). CAT and SOD levels were higher in ISO+VO400 group. The increase in GPx levels was not statistically significant. In histopathological scoring, the values of the ISO group were significantly higher than the control and other VO groups, except for the ISO+VO100 group. In conclusion, considering the ECG findings, antioxidant, pro-inflammatory, cardiac biomarker and histopathological evaluations, it is suggested that VO may have cardioprotective, antioxidant and anti-inflammatory effects, especially in the 400 mg/kg dose group.