Assessment of toxicity and oxidative DNA damage of sodium hypochlorite, chitosan and propolis on fibroblast cells

Abstract The objective of this study was to evaluate and compare the cytotoxicity and genotoxicity on human fibroblast cell lines of sodium hypochlorite (NaOCl), chitosan and propolis as root canal irrigating solutions. Human fibroblast cells were exposed to chitosan, propolis and NaOCl for 4 and 24 h. Cell viability was assessed by 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide, and oxidative DNA damage was assessed by determination of 8-hydroxydeoxyguanosine (8-OHdG) level with an ELISA kit. The data of cell cytotoxicity were analysed statistically using a test of one-way analysis of variance at a significance level of p < 0.05. In the NaOCI group, the 8-OHdG level was higher than in the chitosan group, but there was no statistical difference when compared with the other groups (p < 0.05). It was determined that the irrigation solutions were cytotoxic, depending on the dose and time. NaOCl was the most toxic solution after both 4 and 24 h of exposure (p < 0.05). Chitosan and propolis may be alternatives to NaOCl for irrigation solutions, because they are both less toxic and produce less oxidative DNA damage.

摘要 本研究旨在评估并比较次氯酸钠（sodium hypochlorite, NaOCl）、壳聚糖（chitosan）与蜂胶（propolis）作为根管冲洗液对人成纤维细胞系（human fibroblast cell lines）的细胞毒性与遗传毒性。将人成纤维细胞分别暴露于壳聚糖、蜂胶与次氯酸钠中4小时及24小时。采用2,3-双(2-甲氧基-4-硝基-5-磺苯基)-2H-四唑-5-甲酰苯胺法检测细胞活力，通过酶联免疫吸附测定（ELISA）试剂盒检测8-羟基脱氧鸟苷（8-hydroxydeoxyguanosine, 8-OHdG）水平以评估氧化性DNA损伤。细胞毒性数据采用单因素方差分析（one-way analysis of variance）检验进行统计学分析，显著性水平设定为p<0.05。次氯酸钠组的8-OHdG水平高于壳聚糖组，但与其余两组相比无统计学差异（显著性水平p<0.05）。研究证实，三类根管冲洗液均具有细胞毒性，且毒性作用呈剂量与时间依赖性。暴露4小时及24小时后，次氯酸钠均为毒性最强的冲洗液（p<0.05）。壳聚糖与蜂胶的毒性更低，且引发的氧化性DNA损伤更少，因此二者可作为次氯酸钠的替代根管冲洗液。