Department of Biochemistry, College of Science, King Saud University, P,O Box 22452, Riyadh 11495, Saudi Arabia.
Gut Pathog. 2013 Apr 12;5(1):9. doi: 10.1186/1757-4749-5-9.
Comet assay is a quick method for assessing DNA damage in individual cells. It allows the detection of single and double DNA strand breaks, which represent the direct effect of some damaging agents. This study uses standard comet quantification models to compare the neurotoxic effect of orally administered propionic acid (PA) to that produced as a metabolite of bacterial overgrowth induced by clindamycin. Additionally, the protective effect of carnosine and carnitine as natural dietary supplements is assessed.
Single cell gel electrophoresis (comet assays) were performed on brain cortex and medulla samples after removal from nine groups of hamsters including: a control (untreated) group; PA-intoxicated group; clindamycin treated group; clindamycin-carnosine group and; clindamycin-carnitine group.
There were significant double strand breaks recorded as tail length, tail moment and % DNA damage in PA and clindamycin-treated groups for the cortex and medulla compared to the control group. Neuroprotective effects of carnosine and carnitine were observed. Receiver Operating Characteristics curve (ROC) analysis showed satisfactory values of sensitivity and specificity of the comet assay parameters.
Percentage DNA damage, tail length, and tail moment are adequate biomarkers of PA neurotoxicity due to oral administration or as a metabolite of induced enteric bacterial overgrowth. Establishing biomarkers of these two exposures is important for protecting children's health by documenting the role of the imbalance in gut microbiota in the etiology of autism through the gut-brain axis. These outcomes will help efforts directed at controlling the prevalence of autism, a disorder recently related to PA neurotoxicity.
彗星试验是一种快速评估单个细胞 DNA 损伤的方法。它可以检测单链和双链 DNA 断裂，这代表了一些损伤剂的直接作用。本研究使用标准彗星定量模型来比较口服丙酸（PA）和克林霉素诱导的细菌过度生长的代谢物产生的神经毒性作用。此外，还评估了肌肽和肉碱作为天然膳食补充剂的保护作用。
从包括对照组（未处理）、PA 中毒组、克林霉素处理组、克林霉素-肌肽组和克林霉素-肉碱组在内的九组仓鼠的大脑皮层和延髓样本中进行单细胞凝胶电泳（彗星试验）。
与对照组相比，PA 和克林霉素处理组的大脑皮层和延髓中的双链断裂记录明显，表现为尾部长度、尾部矩和%DNA 损伤。观察到肌肽和肉碱的神经保护作用。受试者工作特征曲线（ROC）分析显示彗星试验参数具有满意的灵敏度和特异性值。
由于口服或作为诱导肠内细菌过度生长的代谢物，百分比 DNA 损伤、尾部长度和尾部矩是 PA 神经毒性的合适生物标志物。建立这两种暴露的生物标志物对于通过肠道-大脑轴记录肠道微生物失衡在自闭症发病机制中的作用来保护儿童健康非常重要。这些结果将有助于控制自闭症的流行，自闭症是一种最近与 PA 神经毒性相关的疾病。
