Qian-Kun-Nin, a Chinese herbal medicine formulation, attenuates mitochondrial oxidant stress in cardiomyocytes

Qian-Kun-Nin is a Chinese herbal medicine formulation used for several indications, including the treatment of cardiovascular diseases. This formulation contains herbs which possess antioxidant properties. In this study, Qian-Kun-Nin's ability to confer protection to cardiomyocytes against reactive oxygen species (ROS) generated during mitochondrial electron transport inhibition was tested. The intracellular fluorescent probe 2′,7′-dichlorofluorescin diacetate (DCFH-DA, sensitive to H₂O₂ and hydroxyl radicals) was used to assess intracellular ROS, and propidium iodide (PI) was used to assess viability in cultured chick embryonic cardiomyocytes. Qian-Kun-Nin significantly attenuated oxidation of DCFH in cells exposed to the mitochondrial site III inhibitor, antimycin A, consistent with a decrease in oxidative stress. These attenuated oxidant levels were associated with improved cell survival. After antimycin A exposure, Qian-Kun-Nin decreased cell death from 51.6 ± 3.3% in untreated cells to 27.3 ± 3.8% in treated cells at 2 h. We conclude that Qian-Kun-Nin attenuates oxidant stress and protects cells from lethal oxidant damage during mitochondrial electron transport inhibition, and thus its therapeutic potential in treating cardiovascular diseases may relate to its antioxidant properties.