The protective effects of alkaloids from <i>Stephania tetrandra</i> S. Moore on H9C2 cardiomyocytes

Alkaloids from <i>Stephania tetrandra</i> S. Moore, particularly tetrandrine, show cardioprotective effects in H9C2 cardiomyocytes under hypoxia/reoxygenation (H/R) injury. Using acid-base extraction and thin-layer chromatography (TLC), HPD-100 resin, Sephadex LH-20, preparative liquid chromatography (prep-HPLC), total alkaloids were purified. In H/R-induced injury (cell viability: 33%), tetrandrine significantly improved viability to 70% and reduced Lactate Dehydrogenase (LDH) release (284-136 U/I), outperforming fangchinoline (viability: 48%; LDH: 223 U/I). Tetrandrine also enhanced glucose consumption (0.62-1.66 nM), lactate production (0.2-0.64 nM), and ATP concentration (5-22 nmoL/mg protein), suggesting metabolic protection. These findings highlight tetrandrine's potential in mitigating myocardial ischemia/reperfusion injury.