Panax notoginseng saponins attenuate cardiomyocyte apoptosis through mitochondrial pathway in natural aging rats.

Panax notoginseng saponins (PNS) have been widely used in the cardiovascular system for the treatment of cardiovascular diseases and stroke in China. In this study, we investigated the anti-apoptotic effect of PNS on cardiomyocytes in the natural aging rat and explored the potential mechanisms regarding oxidative stress and mitochondrial function signaling pathways. Male Sprague-Dawley rats were randomly divided into five groups: adult control (3-month old), aging control (24-month old), and different doses of PNS-treated aging rat groups (10, 30, 60 mg/kg/day, orally). After treatment of PNS or saline for 6 months, the effects of PNS on the cardiomyocytes were evaluated. Results showed that PNS significantly improved the morphological changes in myocardium, prevented the increase of cardiomyocyte apoptosis in the aging rats, and improved mitochondrial dysfunction associated aging in a dose-dependent manner. PNS also significantly reversed the down-regulation of FoxO3a and Mn-SOD and up-regulated PGC-1α, LC3β, and Beclin-1 levels. Our data demonstrated that during aging, mitochondrial dysfunction caused an increase of oxidative damage, which played a key role in cardiomyocyte apoptosis. PNS exerted an anti-apoptotic effect via attenuating oxidative damage through oxidative stress- and mitochondrial function-related signaling pathways.