木犀草素对H_2O_2氧化损伤的血管内皮细胞的影响

Effects of luteolin on endothelial cell injury induced by H_2O_2

目的:探讨木犀草素(luteolin)对氧化损伤的血管内皮细胞(endothelial cells)的影响。方法:体外培养内皮细胞,将细胞分为7组,即空白对照组(control)、溶剂对照组(DMSO)、氧化损伤组(H2O2)、氧化损伤加入槲皮素对照组(quercetin+H2O2)、氧化损伤加入木犀草素低、中、高浓度组(luteolin-L+H2O2、luteolin-M+H2O2、luteolin-H+H2O2)。将750μmol/LH2O2作用于加入槲皮素及不同浓度木犀草素预培养24h的内皮细胞,继续培养18h(半胱氨酸蛋白酶表达测定时间为14h),然后观察木犀草素对细胞培养液内乳酸脱氢酶(LDH)、一氧化氮(NO)、乳酸脱氢酶(LDH)丙二醛(MDA)含量和细胞活力的影响,并对细胞进行流式细胞和免疫组化分析,观察该药对细胞凋亡和半胱氨酸蛋白酶-3(caspase-3)表达的影响。结果:木犀草素呈剂量依赖性降低H2O2对内皮细胞生长抑制率,降低MDA、LDH量,增加培养液中NO2-/NO3-含量,并显著抑制半胱氨酸蛋白酶-3阳性表达,减少细胞凋亡数量,各指标差异显著(P<0.01)。结论:木犀草素可拮抗和修复过氧化氢诱导的血管内皮细胞的损伤,其作用可能与抗氧化、促进NO释放,抑制caspase-3表达有关。

AIM： To study the effect of luteolin on endothelial cell injuries induced by H2O2. METHODS： Endothelial cells were cultured in vitro and divided into seven groups： control; solvent; H2O2 ; quercetin ＋ H2O2 ; luteolin -L ＋ H2O2; luteolin - M ＋ H2O2; luteolin - H ＋ H2O2 group, respectively. Endothelial cells were incubated with 750 μmol/L H2O2 for 18 h or 14 h in the absence or presence of various concentrations of luteolin and quercetin. The expression of caspase -3, the pro- apoptotic factors, was detected by immunohistochemical technique, and the apoptotic index was detected by flow cytometry. Meanwhile, the amount of malondialdehyde （MDA） , nitric oxide （NO）., lacate dehydrogenase （LDH） in serum, and cell viability were measured. RESULTS： Incubation of endothelial cells with H2O2 for 18 h elicited the increase in the extent of immunostaining for caspase -3, the rate of apoptosis, the release of LDH, and the number of dead cells accompanied by the decrease in the content of NO in the medium, which were inhibited by pretreatment of luteolin at concentrations of 0.5 - 50 μmol/L in a concentration - dependent manner （ P 〈 0. 01 ）. CONCLUSION： Luteolin possesses a protective effect against endothelial cell injuries induced by H2O2, which may be related with anti - oxidation, increasing the concentration of NO and inhibiting the activation of caspase - 3.