OBJECTIVETo observe the effects of tetrahydropalmatine, dehydrocorydaline, berberine and palmatine on anoxia and peroxidation injuries in cardiomyocytes, and study the marterial basis of the anti-ischemia effect on myocardium of Rhizoma Corydalis.

METHODNeonatal rat cardiomyocytes were cultured in vitro, and subjected to an anoxia-reoxia and the hydrogen peroxide injury models. The four compounds were added into the culture medium. The cell viability was measured by MTT method to determine the safe concentrations and the anti-hydrogen peroxide injury effects of the compounds. The LDH activity in culture mediums was measured with the enzyme reaction dynamics-monitoring method to value the anti-anoxia injury effects of the compounds.

RESULTAt most up to 500 mg x L(-1), tetrahydropalmatine showed no sinificant effect on the cell viability, while dehydrocorydaline, berberine and palmatine significantly decreased the cell viability, exceeding 6.3, 0.6 and 6.3 mg x L(-1), respectively (P < 0.05 or P < 0.01). Tetrahydropalmatine, dehydrocorydaline, berberine and palmatine significantly inhibited LDH leakage induced by anoxia-reoxia injury, at concentrations of 50-100, 1.25-5, 4 and 30 mg x L(-1), respectively (P < 0.05 or P < 0.01). None of the four compounds showed significant effect on the hydrogen peroxide injury.

CONCLUSIONThe anti-ischemia effect in myocardium of Rhizoma Corydalis is related to the direct protective effects on cardiomyocytes of its components, tetrahydropalmatine, dehydrocorydaline, berberine and palmatine, amomg which tetrahydropalmatine and dehydrocorydaline are the most important, the former with high safety and low efficacy, while the latter with low safety and high efficacy. And the direct protective effects on cardiomyocytes of these four components may be attained through mechanisms other than anti-peroxidation.