Asiatic acid inhibits lactate-induced cardiomyocyte apoptosis through the regulation of the lactate signaling cascade.
Int J Mol Med. 2016 Dec ;38(6):1823-1830. Epub 2016 Oct 20. PMID: 27779647
The lactate signaling cascade has recently been linked to mitochondrial energy metabolism and cardiomyocyte apoptosis in several cardiovascular diseases. Asiatic acid (AA) exhibits a variety of pharmacological effects, including antioxidant and anti-apoptotic effects. In this study, we investigated the protective effects of AA against the lactate-induced apoptosis of cardiomyocytes, as well as its mechanisms of action. Neonatal rat cardiomyocytes were pre-treated with 20 µM AA for 24 h, followed by exposure to 20 mM lactate for a further 24 h. Cell viability was determined by a cell counting kit-8 (CCK-8) assay. Cell apoptosis, reactive oxygen species (ROS) levels and mitochondrial membrane potential (Δψm) were evaluated by flow cytometry or fluorescence microscopy. The expression levels of mitochondrial monocarboxylate transporter 1 (MCT1) and cytoplasmic cytochrome c, cleaved caspase-9 and caspase-3 were assayed by western blot analysis. Our results revealed that AA significantly inhibited lactate-induced apoptosis, intracellular ROSgeneration and the loss of Δψm. AA also increased the expression of mitochondrial MCT1 and reduced the expression of cytoplasmic cytochrome c, cleaved caspase-9 and caspase-3 in the lactate-stimulated cardiomyocytes. To the best of our knowledge, our data demonstrate for the first time that AA plays a cytoprotective role in lactate-induced apoptosis by regulating the lactate signaling cascade, involving the inhibition of oxidative stress and mitochondria-dependent caspase activation, as well as the upregulation of mitochondrial MCT1 expression.