Arsenic (As) uptake and accumulation from agricultural soil to rice vary depending on the soil environmental conditions such as soil pH, redox potential, clay content, and organic matter (OM) content. Therefore, these factors are important in predicting changes in the uptake and accumulation of As in rice plants. Here, we studied the chemical properties of As-contaminated and/or rice straw compost (RSC)-treated soils, the growth responses of RSC-applied rice plants under As-contaminated soils, the changes in As content of soil, and the relationship between As uptake and accumulation from the RSC-treated soils to the rice organs under As-contaminated soils. Rice plants were cultivated in 30 mg kg-1 As-contaminated soils under three RSC treatments: 0 (control), 12, and 24 Mg ha-1. No significant differences were indicated in the chemical properties of pre-experimental (before transplanting rice seedling) soils, with the exception of EC, OM, and available P2O5. As the treatment of RSC under 30 mg kg-1 As-contaminated soils increased, EC, OM, and available P2O5 increased proportionally in soil. Increased soil RSC under As-contaminated soils increased shoot dry weight of rice plants at harvesting stage. As content in roots increased proportionally with RSC content, whereas As content in shoots decreased under As-contaminated soil at all stages of rice plants. Nevertheless, As accumulation were significantly decreased in both roots and shoots of RSC-treated rice plants than those in the plants treated without RSC. These results indicate that the use of RSC can mitigate As phytotoxicity and reduce As accumulation in rice plants under As-contaminated soils. Therefore, RSC can potentially be applied to As-contaminated soil for safe crop and forage rice production.

Background: The plant Aster koraiensis has long been used as an ingredient in folk medicine. It has been reported that Aster koraiensis extract (AKE) prevents the progression of diabetes-induced retinopathy and nephropathy. However, although these beneficial effects of AKE on diabetes complications have been identified, the antidiabetic effects of AKE have not yet been completely investigated and quantified. In the present study, the glucose-lowering and antioxidant effects of aqueous and ethanolic AKEs were evaluated. Methods and Results: The glucose-lowering effects of aqueous and ethanolic (30%−, 50%−, and 80%-ethanol) AKEs were investigated via α-glucosidase inhibitory assays. The mode of inhibition by AKEs on α-glucosidase was identified through kinetic analysis. The total antioxidant capacity of each of the 4 AKEs was evaluated by assessing their conversion rate of Cu2+ to Cu+. The content of chlorogenic acid and 3,5-di-O-caffeoylquinic acid, the bioactive compounds in AKE, in each extract were analyzed by high performance liquid chromatography (HPLC). The AKEs showed potent α-glucosidase inhibitory activity with mixed inhibition mode, and significant antioxidant capacity. Conclusions: These results of this study suggested that the AKEs tested had α-glucosidase inhibitory and antioxidant effects. Among the extracts, the 80% ethanol extract showed the most significant α-glucosidase inhibitory activity, with a half maximal inhibitory concentration (IC50 value) of 1.65 ± 0.36㎎/㎖ and a half maximal effective concentration (EC50 value) for its antioxidant activity of 0.42 ± 0.10㎎/㎖. It can therefore be used as a source of therapeutic agents to treat diabetes patients.

Background : Dry eyes are caused by highly increased osmolarity of tear film, inflammation, and apoptosis of the ocular surface. Polygonum cuspidatum is a herbaceous perennial plant of the genus Polygonum found in Asia and North America. However, the effects of P. cuspidatum aqueous extract (PCE) on hyperosmolarity-induced inflammation and apoptosis in human corneal epithelial cells have not been examined. Methods and Results : Hyperosmotic media induced human corneal epithelial cell (HCEC) cytotoxicity though increased inflammation, apoptosis, and oxidative stress. PCE treatment significantly inhibited expression of cyclooxygenase-2 and inflammatory cytokines (interleukin-6 and tumor necrosis factor-α), and activation of NF-κB p65 in hyperosmolar stress-induced HCECs. In addition, Hyperosmolarity-induced increase in BAX expression and activation of cleaved poly (ADP-ribose) polymerase and caspase 3 were attenuated in a concentration-dependent manner by PCE. PCE treatment restored anti-oxidative proteins such as Heme oxygenase-1 (HO-1), Superoxide dismutase-1 (SOD-1), and Glutathione peroxidase (GPx) in hyperosmolar stress-induced HCECs. Conclusion : PCE protected against hyperosmolar stress-induced inflammation, apoptosis, and oxidation by inhibiting expression of COX-2, BAX, MMP9; activation of NF-κB, caspase 3, and PARP; and increasing expression of MUC4 and anti-oxidative proteins. Overall, our data provide insight into the protective effects of PCE as a candidate for eye health.