Objective: To investigate the efficacy of tilianin extracted from Xiangqinglan () on apoptosis of H9c2 cell after oxygen-glucose deprivation/reoxygenation (OGD/R) and the mechanism.
Methods: Tilianin was obtained from Beijing Inluck Science and Technology Development Co. Ltd., with purity ≥ 98%. The OGD/R model was established in H9c2 cells. Flow cytometry detected the mitochondrial membrane potential, apoptosis rates, mitochondrial reactive oxygen species (ROS) and calcium ion concentration. Succinate dehydrogenase (SDH) activity, succinate content and levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1 β (IL-1β) were detected with enzyme-linked immunosorbent assay. Western blot measured protein levels.
Results: Tilianin significantly reduced the apoptotic rates, ROS levels, calcium ion concentration, succinate content, and, levels of TNF-α, IL-6 and IL-1β of OGD/R cells, while significantly increased the membrane potential and SDH activity in mitochondria. Western blot analysis showed that tilianin significantly up-regulated p-Calmodulin-dependent protein kinase Ⅱ and voltage-dependent anion selective channel levels in OGD/R cells, while significantly down-regulated p-protein kinase B, Bcl-2-associated X, and dynamin-related protein 1 levels related to apoptosis in the mitochondrial pathway. Moreover, tilianin significantly up-regulated B-cell lymphoma-2 and mitochondrial protein 2 related to the inhibition of apoptosis. Furthermore, tilianin down-regulated phosphorylated-apoptosis signal-regulated kinase 1, phosphorylated-p38 and C/EBP homologous protein related to endoplasmic reticulum stress.
Conclusions: Tilianin may inhibit OGD/R-induced H9c2 cell apoptosis mediated by mitochondrial pathway and endoplasmic reticulum stress, thus protecting cardiomyocytes.
Keywords: apoptosis; endoplasmic reticulum stress; mitochondria; oxygen-glucose deprivation/reoxygenation; tilianin.