Protective effect of a marine polyphenol, dieckol against carbon tetrachloride-induced acute liver damage in mouse.

In this study, the hepatoprotective effect of dieckol on carbon tetrachloride (CCl4) induced hepatic damages in ICR mice liver was investigated. Mice were randomly divided into 4 groups such as saline treated (negative control), CCl4 treated (positive control), CCl4+dieckol (5mg/kg mouse) and CCl4+dieckol (25mg/kg mouse), respectively. The body weights and survival rates of mice, followed by dieckol treatments were significantly increased compared to the positive control. The level of GOT, GPT and MDA in the serum of the dieckol treated groups were reduced dose dependently than the control, significantly. The antioxidant enzymes including CAT, and GSH-px levels were increased significantly compared to the positive control. However, no significant differences were observed on hepatic histophathological analysis in dieckol treated groups dose dependently. Down-regulation of Bax and up-regulation of Bcl-xl protein expressions were observed in liver tissues of the dieckol administered groups. These results suggested that, dieckol can be developed as a therapeutic agent for liver disease by oxidative stress.

Antibacterial effect of citrus press-cakes dried by high speed and far-infrared radiation drying methods.

In this study, the antibacterial effect was evaluated to determine the benefits of high speed drying (HSD) and far-infrared radiation drying (FIR) compared to the freeze drying (FD) method. Citrus press-cakes (CPCs) are released as a by-product in the citrus processing industry. Previous studies have shown that the HSD and FIR drying methods are much more economical for drying time and mass drying than those of FD, even though FD is the most qualified drying method. The disk diffusion assay was conducted, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined with methanol extracts of the dried CPCs against 11 fish and five food-related pathogenic bacteria. The disk diffusion results indicated that the CPCs dried by HSD, FIR, and FD prevented growth of all tested bacteria almost identically. The MIC and MBC results showed a range from 0.5-8.0 mg/mL and 1.0-16.0 mg/mL respectively. Scanning electron microscopy indicated that the extracts changed the morphology of the bacteria cell wall, leading to destruction. These results suggest that CPCs dried by HSD and FIR showed strong antibacterial activity against pathogenic bacteria and are more useful drying methods than that of the classic FD method in CPCs utilization.

Bioactive compounds extracted from Ecklonia cava by using enzymatic hydrolysis protects high glucose-induced damage in INS-1 pancreatic ß-cells.

Pancreatic ß-cells are very sensitive to oxidative stress and this might play an important role in ß-cell death in diabetes. In the present study, we investigated whether the brown alga Ecklonia cava has protective effects against high glucose-induced damage in INS-1 pancreatic ß-cells. For that purpose, we prepared an enzymatic hydrolysate from E. cava (EHE) by using the carbohydrase, Celluclast. High-glucose (30 mM) treatment induced glucotoxicity, whereas EHE prevented cells from high glucose-induced damage then restoring cell viability was significantly increased. Furthermore, lipid peroxidation, intracellular reactive oxygen species (ROS) and nitric oxide (NO) were overproduced as the result of the treatment by high glucose; however, these lipid peroxidation, ROS and NO generations were effectively inhibited by addition of EHE in a dose-dependent manner. Moreover, EHE treatment increased activities of antioxidant enzymes including catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-px) in high glucose pretreated INS-1 pancreatic ß-cells. EHE slightly reduced the expression of pro-apoptotic protein Bax induced by high glucose but increased the expression of Bcl-2, an anti-apoptotic protein. These findings indicate that EHE might be used as potential nutraceutical agent which will protect the glucotoxicity caused by hyperglycemia-induced oxidative stress associated with diabetes.

Protective effect of methanol extract from citrus press cakes prepared by far-infrared radiation drying on H(2)O(2)-mediated oxidative damage in Vero cells.

In the present study, a suitable drying method was developed for citrus press cakes (CPCs), which are produced as a by-product in citrus juice plants, and the protective effect of methanol extract of CPCs prepared by far-infrared radiation (FIR) drying against H(2)O(2)-induced DNA damage was evaluated versus that of freeze-dried CPCs. Methanol extract of FIR-dried CPCs exhibited comparatively good ROS scavenging activity versus the freeze-dried CPCs at the concentration of 100 µg/mL. The extract strongly enhanced the cell viability against H(2)O(2)-induced oxidative damage in Vero cells. Lipid peroxidation inhibitory activity of the extract from FIR-dried CPCs was comparable to that of the extract from freeze-dried CPCs. This sample also exhibited good protective effects against H(2)O(2)-mediated cell apoptosis as demonstrated by decreased apoptotic body formation in the nuclear staining with Hoechst 33342. In the comet assay, the CPC extracts exhibited strong inhibitory effects against H(2)O(2)-mediated DNA damage in a dose-dependent manner. Thus, this study demonstrated that FIR drying effectively preserves CPC as a functionally important natural antioxidant source and the FIR drying can be adapted for drying CPCs and is more economical for massive production than freeze drying.