Effects of cembrane-type diterpenes on proliferation of PC12 cells and their antagonistic effects on neurotoxicity induced by glutamate

Abstract

To investigate the effects of cembrane-type diterpenes extracted from Sinularia flexibilis on the proliferation of PC12 cells and their protective effects on PC12 cells exposed to glutamate. Methyl thiazolyl tetrazolium (MTT) method was adopted to observe the effects of cembrane-type diterpenes (compound 1, compound 2 and compound 3) on the proliferation of PC12 cells. And the protective effects of the three compounds on PC12 cells exposed to glutamate were also detected by MTT. Furthermore, the influence of compound 1 on intracellular concentration of calcium in PC12 cells exposed to glutamate was detected by laser confocal microscopy. After 72-hour PC12 cell culture, OD values in the 2, 10 and 50 micromol/L compound 1 groups were significantly higher than that in the normal group (P<0.05, P<0.01). After 24-hour glutamate damage, OD values in the 0.4, 2 and 50 micromol/L compound 1 groups, the 0.4, 2 and 100 micromol/L compound 2 groups and the 2 micromol/L compound 3 group were obviously increased as compared with the untreated group (P<0.01, P<0.05). After 48-hour glutamate damage, OD values in the compound 1 group were approximate to those in the normal control and the positive control group while were significantly higher than that in the untreated group (P<0.01, P<0.05), but no dose-dependent effect was observed. Compound 1 of 0.4, 2, 50 micromol/L could significantly reduce the intracellular concentration of calcium in PC12 cells exposed to glutamate (P<0.05, P<0.01), which was also approximate to the effect of nimodipine (positive control drug). Cembrane-type diterpenes (compound 1, compound 2 and compound 3) extracted from Sinularia flexibilis have obvious protective effects on PC12 cells damaged by glutamate, and compound 1 has the best neuroprotective effect. The mechanism of the neuroprotective effect of compound 1 may lie in reducing the intracellular concentration of calcium in PC12 cells exposed to glutamate and relieving the calcium overload.