不同粒径碳酸钙对HCT-8细胞的氧化损伤作用

The oxidative damage caused by different sizes of calcium carbonate particles in HCT-8 cells

目的体外观察不同粒径碳酸钙(CaCO3)颗粒对人回盲肠上皮HCT-8细胞的细胞毒性和氧化损伤作用。方法将细胞分别暴露于微米和纳米CaCO3颗粒,测定不同染毒剂量和时间对HCT-8细胞活力(MTT法)及细胞内活性氧(ROS)、超氧化物歧化酶(SOD)、谷胱甘肽(GSH)及丙二醛(MDA)水平的影响。结果微米和纳米CaCO3颗粒均可导致细胞活力降低、细胞内ROS及MDA产生增多、而SOD及GSH含量下降(P<0.05),并呈剂量依赖性。在相同剂量水平下,纳米颗粒的毒性大于微米颗粒,而维生素C可减轻CaCO3颗粒造成的细胞毒性和氧化损伤。结论 CaCO3颗粒在体外对HCT-8细胞的毒性与剂量和粒径相关,氧化损伤可能是造成CaCO3颗粒细胞毒性的原因之一。

Objective To compare the cytotoxic effects and the oxidative damage caused by micro- and nano- calcium carbonate particles in human ileocecal adenocarcinoma HCT-8 cells in vitro. Methods Cell viability was determined by the MTT assay. Induction of the oxidative stress was assessed by determining the level of intracellular ROS, SOD, GSH and MDA levels after exposure of cells to increasing concentrations of either micro- or nano- calcium carbonate particles separately. Results Both micro- and nano-particles dose- dependently reduced cell viability and induced the generation of reactive oxygen species （ROS） followed by a significant depletion of GSH, SOD activities and accumulation of MDA. But at the same dose level nanoparticles are more cytotoxic and caused more severe oxidative stress than microparticles. Co-treatment of cells with calcium carbonate particles and the antioxidant vitamin C increased cell viability and mitigated the oxidative stress, suggesting that oxidative stress may be one of the causes of the cytotoxic effect of calcium carbonate particles. Conclusion The cytotoxic effect of calcium carbonate particles on HCT-8 cells is dose- and size-related. Oxidative stress is possibly the underlying mechanism by which calcium carbonate particles caused cytotoxicity.