Buccigrossi Vittoria, Russo Carla, Guarino Amedeo, de Freitas Maiara Brusco, Guarino Alfredo
Department of Translational Medical Science, Section of Pediatrics, University of Naples Federico II, via S. Pansini 5, 80131 Naples, Italy.
Department of Nutrition, Federal University of Santa Catarina, Florianópolis, Santa Catarina Brazil.
Gut Pathog. 2017 Apr 24;9:23. doi: 10.1186/s13099-017-0172-2. eCollection 2017.
Rotavirus (RV) induces diarrhoea through a sequence of enterotoxic and cytotoxic effects. The former are NSP4-dependent, induce calcium-dependent chloride secretion and involve oxidative stress. Diosmectite (DS) is a natural clay that has been recommended as an active therapy for diarrhoea, but the mechanism of its effect is not clear. Electrical parameters may be used to measure the direct enterotoxic and cytotoxic effects in polar epithelial intestinal cells. To investigate the effects of DS on RV-induced enterotoxic and cytotoxic damage. Caco-2 cells were used as a model of RV infection to evaluate chloride secretion, epithelial integrity, oxidative stress and viral infectivity in Ussing chambers.
Diosmectite reduced the expression of NSP4 and oxidative stress, resulting in a strong inhibition of chloride secretion. Preincubating RV with DS reduced the cytotoxic effect. Finally, the viral load was reduced by DS but not by control clay. This result suggests that DS specifically affects the early events of RV infection protecting the enterocyte, whereas it does not restore already-established cell damage.
These findings indicate that DS exerts an anti-diarrhoeal effect by inhibiting viral replication and the expression of NSP4. Both ion secretion and cell damage induced by RV are strongly inhibited consequent to the antiviral effect, which explains its clinical efficacy.
轮状病毒（RV）通过一系列肠毒素和细胞毒素作用引发腹泻。前者依赖NSP4，诱导钙依赖性氯化物分泌并涉及氧化应激。蒙脱石（DS）是一种天然粘土，已被推荐作为腹泻的有效治疗方法，但其作用机制尚不清楚。电参数可用于测量极性上皮肠细胞中的直接肠毒素和细胞毒素作用。为了研究DS对RV诱导的肠毒素和细胞毒素损伤的影响。使用Caco-2细胞作为RV感染模型，在Ussing室中评估氯化物分泌、上皮完整性、氧化应激和病毒感染性。
蒙脱石降低了NSP4的表达和氧化应激，从而强烈抑制了氯化物分泌。用DS预孵育RV可降低细胞毒性作用。最后，DS降低了病毒载量，但对照粘土则没有。这一结果表明，DS特异性地影响RV感染的早期事件，保护肠上皮细胞，而不能恢复已经造成的细胞损伤。
这些发现表明，DS通过抑制病毒复制和NSP4的表达发挥抗腹泻作用。由于抗病毒作用，RV诱导的离子分泌和细胞损伤均受到强烈抑制，这解释了其临床疗效。
