Dracocephalum Moldavica L. Extracts Protect H9c2 Cardiomyocytes Against H ₂ O ₂-Induced Apoptosis and Oxidative Stress

Materials and methods: The petroleum ether (petrol), dichloromethane (CH₂Cl₂), ethyl acetate (EtOAc), and n-butyl alcohol (n-BuOH) fractions were isolated from alcohol extracts of D. moldavica L. Total phenolic and flavonoid contents and in vitro antioxidant activities of different fractions were evaluated. H9c2 cells were then treated with D. moldavica L. extracts before challenging with H₂O₂. Cell viability was determined by colorimetric assay, and ELISA was used to measure the levels of lactate dehydrogenase (LDH), malondialdehyde (MDA), and superoxide dismutase (SOD). Apoptosis levels and mitochondrial membrane potential were measured by flow cytometry. The expressions of cell apoptosis regulatory proteins caspase-3, Bax, and Bcl-2 were determined by western blotting.

Results: Our results demonstrated that the EtOAc fraction from D. moldavica L. ethanol extract, which is rich in phenolic and flavonoid active constituents, had the strongest free radical scavenging activity. Additionally, this fraction increased H₂O₂-induced reduction in cell viability, SOD activity, and mitochondrial membrane potential. It also reduced H₂O₂-induced elevation in ROS production, contents of LDH and MDA, and H9c2 apoptosis. We further found that the EtOAc fraction increased Bcl-2 expression, while it decreased caspase-3 and Bax expressions induced by H₂O₂ in H9c2 cells.

Conclusions: Our data revealed that the EtOAc fraction from D. moldavica L. ethanol extract ameliorates H₂O₂-induced cardiotoxicity via antiapoptotic and antioxidant mechanisms.