Gastroprotective effects of Chinese Rana chensinensis skin collagen against ethanol-induced gastric ulcer in mice.

Gastric ulcer is a common gastrointestinal disease caused by excessive gastric acid secretion, which has been recognized as one of the most common causes of morbidity and mortality in the world. The skin of Rana chensinensis is rich in collagen and many previous studies have shown that it has certain bioactivity. Therefore, we extracted and purified collagen with a molecular weight less than 10000 Da from the skin of Rana chensinensis, and studied its gastric protective mechanism through the model of ethanol-induced gastric ulcer in Balb/c mice. The results showed that through macroscopic observation and significantly reduced ulcer index, it was proved that PCRCS could protect gastric mucosa and alleviate the damage of ethanol to gastric mucosa. PCRCS reduced ethanol-induced oxidative stress by boosting depleted SOD levels and dramatically lowering MDA levels, as well as significantly reducing lipid peroxidation. Additionally PCRCS (Protein Chinese Rana chesinensis Skin) additionally decreased the launch of inflammatory mediators TNF-α and IL-6 and more desirable the content material of protective elements NO and PGE2 in gastric mucosa. Based on these findings, we believe that PCRCS has potential stomach protective effects on ethanol-induced gastric ulcer, which may be achieved by inhibiting oxidative stress and stomach inflammation.

MicroRNA-365 Knockdown Prevents Ischemic Neuronal Injury by Activating Oxidation Resistance 1-Mediated Antioxidant Signals / 神经科学通报·英文版

MicroRNA-365 (miR-365) is upregulated in the ischemic brain and is involved in oxidative damage in the diabetic rat. However, it is unclear whether miR-365 regulates oxidative stress (OS)-mediated neuronal damage after ischemia. Here, we used a transient middle cerebral artery occlusion model in rats and the hydrogen peroxide-induced OS model in primary cultured neurons to assess the roles of miR-365 in neuronal damage. We found that miR-365 exacerbated ischemic brain injury and OS-induced neuronal damage and was associated with a reduced expression of OXR1 (Oxidation Resistance 1). In contrast, miR-365 antagomir alleviated both the brain injury and OXR1 reduction. Luciferase assays indicated that miR-365 inhibited OXR1 expression by directly targeting the 3'-untranslated region of Oxr1. Furthermore, knockdown of OXR1 abolished the neuroprotective and antioxidant effects of the miR-365 antagomir. Our results suggest that miR-365 upregulation increases oxidative injury by inhibiting OXR1 expression, while its downregulation protects neurons from oxidative death by enhancing OXR1-mediated antioxidant signals.