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.

The aim of the present study was to evaluate the beneficial effects of Eriobotryae Folium on diabetic improvement through oxidative stress and inflammation in the liver of type 2 diabetic db/db mice. Eriobotryae Folium extract (100 or 200 mg/kg body weight, p.o) was administrated everyday for 3 weeks. And then, its effect was assessed on comparison with vehicle-treated db/db and non-diabetic m/m mice. Serum glucose and hepatic tissue biochemical factors and protein expression related with oxidative stress and inflammation such as reactive oxygen species (ROS) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase were measured. As a result, the administration of Eriobotryae Folium decreased body and liver weight, food intake in vehicle-treated db/db. Also, serum glucose was lowered by Eriobotryae Folium treatment. Eriobotryae Folium administration decreased oxidative stress through the down-regulation of ROS and NADPH oxidase subunit proteins, NOX-4 and p47 phox .Moreover,theincreaseofinflammatoryproteinssuchasinduciblenitricoxidesynthase(iNO S),cyclooxygenase-2(COX-2),tumornecrosisfactoralpha(TNF-α), interleukin-6 (IL-6) on vehicle-treated db/db were significantly decreased through down-regulation nuclear factor-kappa B (NF-κB) and activator pretoein-1 (AP-1) via reduction of oxidative stress. Therefore, hepatic functional parameters such as alanine aminotransferase, aspartate aminotransferase significantly decreased. In conclusion, Eriobotryae Folium extract could have hepato-protective effect through down-regulation of abnormal NADPH oxidase subunit and the oxidative stress in type 2 diabetic db/db mice.

To evaluate therapeutic efficacy of aldose reductase (AR) inhibition, the seeds of Perilla frutescens var. japonica (PF) were tested for inhibition of AR. The stepwise polarity fractions of PF were tested. The CH2Cl2 and EtOAc fractions showed highest activities (IC50 5.47 and 3.63 μg/mL, respectively). Compounds 1-5 were isolated from the CH2Cl2 and EtOAc fractions by silica-gel and LH-20 Sephadex. Their structures were elucidated as β-sitosterol (1), diosmetin (2), kaempferol (3), luteolin (4), and apigenin (5). Compounds 1-5 were exhibited AR inhibitory. Among them, luteolin (4) and apigenin (5) exhibited AR inhibitory activities (IC50 0.40 and 1.10 μg/mL, respectively). Our results demonstrated that PF could be a worthy natural source for curing against diabetic complications.

Content analysis of loliolide in the leaves of Boehmeria nivea (Bn) collected from different region during four months (June, July, August, and September) was conducted by HPLC. The content of loliolide was detected in the leaves of B. nivea from Bns-2, -7, -10, -23, -38, -41, -67, -76, and -90 in June (5.02, 6.35, 6.93, 5.89, 4.31, 4.24, 4.91, 5.12, and 5.46 mg/g, respectively), July (4.32, 6.42, 7.72, 7.97, 4.05, 4.32, 5.65, 6.67, and 5.39 mg/g, respectively), August (3.52, 5.17, 3.90, 4.27, 3.26, 4.72, 3.82, 3.30, and 3.31 mg/g, respectively), and September (7.04, 7.25, 7.43, 7.86, 6.76, 6.38, 7.60, 6.79, and 4.77 mg/g, respectively). Among them, the highest content of loliolide was found in Bn-23 and in September. These results may be useful in determining the optimal harvest time at which phytochemical reaches a maximum level.

To evaluate therapeutic efficacy of aldose reductase (AR) inhibition, the leaves of Aster yomena were tested for inhibition of AR. The stepwise polarity fractions of A. yomena were tested. Among them, the n-BuOH fraction showed highest activities against AR inhibition. Our results demonstrated that A. yomena could be a worthy natural source source for curing against diabetic complications.