Influence of modified atmosphere treatment on post-harvest reactive oxygen metabolism of pomegranate peels.

Modified atmosphere storage can regulate the reactive oxygen metabolism of fruits and vegetables, reduce the accumulation of hazardous free radicals, and mitigate the peroxidation degree of fruit membrane lipids. In this study, different gas matching ratios were adopted for the modified atmosphere treatment of pomegranate fruits. Up to 120 d of storage, compared with the control treatment, the H2O2 and malonaldehyde (MDA) contents in treatment 2 decreased by 8.88% and 18.28%, respectively, when the activities of superoxide dismutase (SOD), catalase (CAT) and ascorbic acid peroxidase (APX) in treatment 2 increased by 21.44%, 117.38% and 114.95%, the ascorbic acid (ASA) and glutathione (GSH) contents in treatment 2 also increased by 116.83% and 50%, these results showed that treatment 2 (6.0% O2, 6.0% CO2) could effectively regulate various indexes of the reactive oxygen metabolism of pomegranate peels, maintain the normal physiological actions of the fruits, and postpone the ripening and senescence of histocytes. Under treatment 4 (10.0% O2, 10.0% CO2), H2O2 contents in the pomegranate peel significantly increased, and the activities of SOD, CAT and APX significantly reduced. ASA and GSH were degraded, the MDA content abruptly increased, the membrane lipid peroxidation accelerated, and the cytomembrane structure was destroyed.

Chemical composition and hepatoprotective effect of free phenolic extract from barley during malting process.

In this study, No.Ganpi4 of barley was steeped and malted to investigate the changes of phenolic compounds during malting process. The free phenolic extract from raw barley (FPEB) was analyzed by HPLC and predominant compounds were (+)-catechin, protocatechuate and quercetin. The FPEB was evaluated for hepatoprotective effect in vivo and in vitro. Intragastric administration of FPEB (100, 200 and 400 mg/kg/bw) to mice significantly weakened the effects of hepatic damage induced by CCl4 toxicity on serum markers, including serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total-bilirubin, total cholesterol and total triglycerides. FPEB administration also increased the hepatic levels of antioxidant enzymes, such as superoxide dismutase, catalase and glutathione peroxidase. Histopathological examinations further confirmed that FPEB could protect the liver from CCl4-induced damage. In vitro, the experimental results demonstrated that FPEB could reduce BRL hepatocyte apoptosis and damage induced by CCl4. These results suggest that FPEB exerts an effective protection for hepatic injury, and barley has the potential as a functional food to prevent hepatic injury.

Enrichment and Purification of Polyphenol Extract from Sphallerocarpus gracilis Stems and Leaves and in Vitro Evaluation of DNA Damage-Protective Activity and Inhibitory Effects of α-Amylase and α-Glucosidase.

An efficient preparative separation method for Sphallerocarpus gracilis stems and leaves polyphenols (SGslP) was established in this study. An X-5 macroporous adsorption resin was selected for the purification of the SGslP, and the polyphenol content of the purified SGslP (PSGslP) was increased 5.11-fold from 8.29% to 42.38% after one treatment run. The chemical composition of the PSGslP was analyzed by HPLC-MS/MS, and the predominant compounds were found to be luteolin-7-glucoside, acacetin-7-acetyglycoside and its isomers. In addition, the PSGslP was evaluated in vitro to determine the DNA damage-protective activity and inhibitory effects of α-amylase and α-glucosidase. The results indicated that the PSGslP exhibited significant protective activities against both ROO• and •OH radical-induced DNA damage. Moreover, the PSGslP exerted a dose-dependent inhibition effect on α-glucosidase but no inhibitory effect on α-amylase. These findings indicate that the Sphallerocarpus gracilis stems and leaves are good natural sources of antioxidants and are potent inhibitors of α-glucosidase activity and are potential anti-diabetic inhibitor.

Phenolic composition, DNA damage protective activity and hepatoprotective effect of free phenolic extract from Sphallerocarpus gracilis seeds.

The phenolic composition of the free phenolic extract from Sphallerocarpus gracilis seeds was analyzed by HPLC-MS and predominant compounds were chlorogenic acid, di-caffeoylquinic acid glucoside and luteolin-7-O-glucoside. The free phenolic extract was evaluated for DNA damage protective activity induced by ROO and OH radicals and hepatoprotective effect in vivo and in vitro. Results revealed that the free phenolic extract exhibited significant protective activity against both ROO and OH radical-induced DNA damage and the phenolic extract exerted more potent inhibitory activity against OH radical-induced damage than against that induced by ROO radicals. In vivo experimental results showed that the phenolic extract significantly prevented the increase of serum alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase activities and hepatic malondialdehyde level caused by CCl4 in rats, and markedly increased hepatic superoxide dismutase, catalase and glutathione peroxidase levels. Histopathological examinations further confirmed that the phenolic extract could protect the liver from CCl4-induced damage. In vitro experimental results showed that the phenolic extract could reduce BRL hepatocyte apoptosis and damage induced by CCl4. These findings indicate that the S. gracilis seed could be developed as a medicinal herb for the therapy and prevention of hepatic injury.

Studies on the antioxidant activity and phenolic compounds of enzyme-assisted water extracts from Du-zhong (Eucommia ulmoides Oliv.) leaves.

Enzyme-assisted water extracts (EWEDL) and ethanol extracts of Du-zhong leaves (EEDL) were evaluated for their antioxidant activities using the DPPH radical-scavenging assay, Fe(2+)-chelating assay, and inhibition ability of the linoleic acid peroxidation assay. In general, the antioxidant activity of Du-zhong leaf extracts increased with increasing concentration. Based on the two extracting methods with different antioxidative reactions, it was shown that the enzyme-assisted water extracting method was more effective for antioxidant extraction from Du-zhong leaves. By HPLC-MS analysis, the main phenolic compounds (geniposidic acid, epicatechin, and chlorogenic acid) identified in EWEDL and EEDL were similar. EWEDL and EEDL had total phenolic contents of 13.84 +/- 0.11 and 14.72 +/- 0.14 mg chlorogenic acid equivalents (CAE) in each gram of extract, respectively. However, there was no positive correlation between total phenolic content and antioxidant activities of EWEDL and EEDL measured by the three different assays.