Division of Endodontics, Department of Semiology and Clinics, Faculty of Dentistry, Federal University of Pelotas, Pelotas, Brazil.
J Endod. 2010 Feb;36(2):268-71. doi: 10.1016/j.joen.2009.09.025. Epub 2009 Dec 4.
This study investigated the inhibition of the antimicrobial activity of sodium hypochlorite (NaOCl) by bovine serum albumin (BSA). The killing of Enterococcus faecalis, Candida albicans, Staphylococcus epidermidis, and Escherichia coli by NaOCl in concentrations from 2% to 0.03% was measured in the presence of BSA in concentrations between 6.7% and 0.1%.
NaOCl, BSA, and microorganism suspensions were mixed, and, after 30 seconds, 6 minutes, and 30 minutes, samples were taken and NaOCl was inactivated by 5% sodium thiosulphate. The microbes were incubated in tryptic soy broth broth for up to 7 days for the detection of growth.
All microorganisms were killed within 30 seconds by 0.03% NaOCl when BSA was not present. High concentrations of BSA significantly reduced the antimicrobial activity of NaOCl against the four species.
The inhibition of sodium hypochlorite by BSA was directly dependent on their quantitative relationships. The result partly explains the poorer performance in vivo of NaOCl as compared to in vitro experiments.
本研究旨在探究牛血清白蛋白（BSA）对次氯酸钠（NaOCl）抗菌活性的抑制作用。通过将浓度为 2%至 0.03%的 NaOCl 与浓度为 6.7%至 0.1%的 BSA 混合，测量了其对粪肠球菌、白色念珠菌、表皮葡萄球菌和大肠杆菌的杀灭效果。
将 NaOCl、BSA 和微生物悬浮液混合，在 30 秒、6 分钟和 30 分钟后取样，并用 5%硫代硫酸钠使 NaOCl 失活。将微生物在胰蛋白酶大豆肉汤中孵育长达 7 天，以检测其生长情况。
当不存在 BSA 时，浓度为 0.03%的 NaOCl 在 30 秒内即可杀死所有微生物。高浓度的 BSA 显著降低了 NaOCl 对四种细菌的抗菌活性。
BSA 对次氯酸钠的抑制作用与其定量关系直接相关。这一结果部分解释了 NaOCl 在体内的表现不如体外实验的原因。
