Background : We have previously reported that Oligonol, a low-molecular polyphenol derived from lychee fruit, has protective effect on the liver and kidney of diabetic animal model. In this study, we examined whether Oligonol has any beneficial effects on pancreas of diabetic rats. Methods and Results : Oligonol was orally administered at a dose of 10 and 20 mg/kg body weight for 10 days to STZ-induced diabetic rats, and the effects were compared with those of vehicle-treated diabetic control and non-diabetic control rats. The administration of Oligonol reduced hyperglycemia in diabetic rats through an improvement of serum and pancreatic insulin levels. The increased reactive oxygen species levels in pancreas of diabetic control rats was attenuated by the Oligonol administration through inhibiting the expression of NADPH oxidase-related proteins. The enhanced expression of pro-apoptotic proteins in pancreas of diabetic control rats was significantly reduced by Oligonol administration through down-regulation of phosphor-c-Jun N-terminal kinases protein in pancreas. Furthermore, the expressions of cell proliferation-related protein were also augmented in Oligonol treated-diabetic rats. However, Oligonol treatment led to improved histological changes in the pancreas. Conclusion : These pancreatoprotective effects of Oligonol were achieved through attenuation of oxidative stress and its sensitive protein expression associated with apoptosis and cell proliferation in diabetic rats.
Purpose Rhei Rhizoma (RR) is one of the herbal medicines traditionally used to treat diverse inflammatory diseases. The present study was undertaken to elucidate the antioxidant and anti-inflammatory activities of Rhei Rhizoma on experimental reflux esophagitis (RE) in rats. Methods The antioxidant activity of RR in vitro was measured in terms of radical scavenging capacity such as DPPH and ABTS. RE was produced by ligating both the pylorus and the transitional junction between the forestomach and the corpus. Rhei Rhizoma (125 and 250 mg/kg) were administered every day for 7 days, and its effect was estimated on comparison with RE control and normal rats. Results RR scavenged DPPH and ABTS effectively and IC50ofDPPH and ABTS radical scavenging activity of RR were 4.8 μg/ml and 15.75 μg/ml. The administration of RR decreased the elevated serum ROS in RE control rats. The RE control rats exhibited the down-regulation of antioxidant-related proteins such as Nrf2 and HO-1expression levels in the esophagitis; however, the level in the RR-treated RE rats was significantly higher than that in the RE control rats. Moreover, RE control rats exhibited the up-regulation of the protein expression related to oxidative stress at the esophagitis, but RR administration significantly reduced the expression of inflammatory proteins through the MAPK-independent signaling pathways. The expression of inflammatory mediators and cytokines by NF-κB activation was modulated through blocking the degradation of IκBα. In addition, the oral administration of RR regulated the gastric mucosal damage in RE rats. Conclusion The administration of Rhei Rhizoma effectively ameliorates the inflammatory damage of esophageal mucosa through radical scavenging activity and the activation of the Nrf2/HO-1 pathway.
Characteristics related to grain quality and starch viscosity were investigated in three independent japonica transgenicrice lines expressing a Protox gene from Bacillus subtilis and compared to the control. In this study, we found that there were nosigni