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This study investigates the catechin composition and protective effect of green tea extract on senescence-mediated redox imbalance in the livers and kidneys of aged mice. The results showed that the seven catechins in the green tea extract analyzed in this study could be completely separated within 30 min and the main components of catechins in green tea extract were EGCG, EGC and ECG. In terms of the anti-senescence effects of green tea extract, green tea extract supplementation at doses of 125, 625 and 1250 mg/kg for 4 weeks significantly alleviated the senescence-mediated redox imbalance, as exhibited from significantly ( p < 0.05) reduced thiobarbituric acid-reactive substances (TBARS) and protein carbonyls levels in the serum, and increased glutathione (GSH) and total thiols contents in the plasma. Additionally, hepatic and renal protein carbonyls levels were significantly diminished ( p < 0.05) and the activities of superoxide dismutase (SOD), catalase, glucose-6-phosphate dehydrogenase (G6PD), glutathione peroxidase (GSH-Px) and glutathione reductase (GSH-Rd) in the liver and kidney were remarkably elevated ( p < 0.05). Overall, these results clearly show that green tea extract exhibits extremely potent protective effects against senescence-mediated redox imbalance in the livers and kidneys of mice by inhibiting oxidative damage of lipids and proteins and increasing the activities of antioxidant enzymes in organs.

Cataracts are the major cause of blindness and are associated with oxidative damage of the lens. In the present study, the aim was to evaluate the protective effects of rosmarinic acid on selenite-induced cataractogenesis in Sprague-Dawley rat pups. The animals were randomly divided into five groups, each of which consisted of 10 rat pups. Group I served as normal control (vehicle administration). For testing cataract induction, animals of Groups II, III, IV, and V were administered a single subcutaneous injection of sodium selenite (2.46 mg/kg body weight) on postpartum day 12. After sodium selenite intoxication, Group II served as control selenite. From the 11th day through the 17th day, Groups III-V received rosmarinic acid intraperitoneally at doses of 5, 10, and 50 mg/kg, respectively. On postpartum day 24, the rat pups were examined for cataract formation, and the lenses were isolated for further analysis of proteins and oxidative damage indicators. Selenite caused significant ( p < 0.05) cataract formation. Through the effects of selenite, the protein expressions of filensin and calpain 2 were reduced, and the calcium concentrations, the level of lipid peroxidation (TBARS), and inflammation indicators (iNOS, COX-2, and NFκB) were upregulated. Furthermore, the protein expression of the antioxidant status (Nrf2, SOD, HO-1, and NQO1), the antioxidant enzymes activities (GSH-Px, GSH-Rd, and catalase), and the GSH levels were downregulated. In contrast, treatment with rosmarinic acid could significantly ( p < 0.05) ameliorate cataract formation and oxidative damage in the lens. Moreover, rosmarinic acid administration significantly increased the protein expressions of filensin, calpain 2, Nrf2, SOD, HO-1, and NQO1, the antioxidant enzymes activities, and the GSH level, in addition to reducing the calcium, lipid peroxidation, and inflammation indicators in the lens. Taken together, rosmarinic acid is a prospective anti-cataract agent that probably delays the onset and progression of cataracts induced by sodium selenite., Competing Interests: Competing Interests: The authors have declared that no competing interest exists.

The in vivo antioxidant and antifibrotic properties of green tea (Camellia sinensis, Theaceae) were investigated with a study of carbon tetrachloride (CCl(4))-induced oxidative stress and hepatic fibrosis in male ICR mice. Oral administration of green tea extract at doses of 125, 625 and 1250 mg/kg for 8 weeks significantly reduced (p<0.05) the levels of thiobarbituric acid-reactive substances (TBARS) and protein carbonyls in the liver by at least 28% compared with that was induced by CCl(4) (1 mL/kg) in mice. Moreover, green tea extract administration significantly increased (p<0.05) the activities of catalase, glutathione peroxidase (GSH-Px) and glutathione reductase (GSH-Rd) in the liver. Our study found that oral administration of green tea extract prevented CCl(4)-induced hepatic fibrosis, as evidenced by a decreased hydroxyproline level in the liver and a reduced incidence of hepatic fibrosis by histological observations. These results indicate that green tea exhibits potent protective effects against CCl(4)-induced oxidative stress and hepatic fibrosis in mice by inhibiting oxidative damage and increasing antioxidant enzyme activities., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Purpose: Ultraviolet B (UVB) radiation from sunlight is known to be a risk factor for human corneal damage. The purpose of this study was to investigate the protective effects of Dunaliella salina (D. salina) on UVB radiation-induced corneal oxidative damage in male imprinting control region (ICR) mice., Methods: Corneal oxidative damage was induced by exposure to UVB radiation at 560 μW/cm(2). Animals were orally administered (gavage) D. salina at doses of 0, 123, and 615 mg/kg bodyweight/day for eight days. Corneal surface damages were graded according to smoothness and the extent of lissamine green staining. Corneal glutathione (GSH) and malondialdehyde (MDA) levels, as well as the activities of superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH-Px), and glutathione reductase (GSH-Rd) in cornea were measured to monitor corneal injury., Results: UVB irradiation caused significant damage to the corneas, including apparent corneal ulcer and severe epithelial exfoliation, leading to decrease in the activities of SOD, catalase, GSH-Px, GSH-Rd, and GSH content in cornea, whereas there was increased corneal MDA content as compared with the control group. Treatment with D. salina could significantly (p<0.05) ameliorate corneal damage and increase the activities of SOD, catalase, GSH-Px, GSH-Rd, and GSH content, and decrease the MDA content in corneas when compared with the UVB-treated group., Conclusions: The studies demonstrate that D. salina exhibits potent protective effects on UVB radiation-induced corneal oxidative damage in mice, likely due to both the increase of antioxidant enzyme activity and the inhibition of lipid peroxidation.

Abstract: Lutein and zeaxanthin were extracted from daylily (Hemerocallis disticha) flowers using supercritical fluid extraction-carbon dioxide (SFE-CO2) at a temperature range of 50–95°C and pressure range of 300–600bar. The extracts were analysed by HPLC with a C30 column and an isocratic solvent system: methanol/methyl-tert-butyl ether=86/14 (v/v). Moreover, the antioxidant capacities of the extracts were evaluated by a 2,2-diphenyl-2-picrylhydrazyl radical scavenging assay and a chemiluminescence assay to measure the scavenging activity of hydrogen peroxide, superoxide anion and hydroxyl radical. The optimal lutein and zeaxanthin extraction could be achieved at 80°C and 600bar, and the extraction pressure was the most important parameter for SFE-CO2. In addition, the extracts had significantly higher antioxidant activities in all antioxidant assays. [Copyright &y& Elsevier]

Abstract: Green tea is believed to be beneficial to health because it possesses antioxidant, antiviral and anticancer properties. The potential toxicity of green tea when administered at high doses via concentrated extracts, however, has not been completely investigated. The objective of the present study was to evaluate the safety of green tea extract in ICR mice using a subacute exposure paradigm. In this study, mice were orally administered (gavage) green tea extract at doses of 0 (as normal group), 625, 1250 and 2500mg/kgbody weight/day for 28days. The results showed that oral administration of green tea extract did not cause adverse effects on body weight, organ weights, hematology, serum biochemistry, urinalysis or histopathology. Additionally, administering green tea extract via gavage significantly reduced triglyceride and cholesterol levels. These observed effects could be attributed to the high levels of catechins present in green tea as these compounds have been reported to have beneficial health effects. The no-observed-adverse-effect level for green tea extract derived from the results of the present study was 2500mg/kgbody weight/day. [Copyright &y& Elsevier]

Abstract: The antioxidant capacity of seabuckthorn (Hippophae rhamnoides L.) seed oil was investigated with a number of established in vitro assays and in an in vivo study of carbon tetrachloride (CCl4)-induced oxidative stress in mice. The results showed that DPPH radical scavenging activity, ferrous ion chelating activity, reducing power and inhibition of lipid peroxidation activity all increased with increasing concentrations of seabuckthorn seed oil. Moreover, the EC50 values of seabuckthorn seed oil from the hydrogen peroxide, superoxide radical, hydroxyl radical scavenging assays were 2.63, 2.16 and 0.77mg/ml, respectively. In the in vivo study, seabuckthorn seed oil inhibited the toxicity of CCl4, as seen from the significantly increased activities of the antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase. The GSH content in the liver was also increased, whereas hepatic malondialdehyde was reduced. Taken together, these results clearly indicate that seabuckthorn seed oil has significant potential as a natural antioxidant agent. [ABSTRACT FROM AUTHOR]

Abstract: The protective effects of MegaHydrate™ silica hydride against liver damage were evaluated by its attenuation of carbon tetrachloride (CCl4)-induced hepatotoxicity in mice. Male ICR mice were orally treated with silica hydride (104, 208 and 520mg/kg) or silymarin (200mg/kg) daily, with administration of CCl4 (1mL/kg, 20% CCl4 in olive oil) twice a week for eight weeks. The results showed that oral administration of silica hydride significantly reduced the elevated serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), triglyceride (TG), and cholesterol and the level of malondialdehyde (MDA) in the liver that were induced by CCl4 in mice. Moreover, the silica-hydride treatment was also found to significantly increase the activities of superoxide dismutase (SOD), catalase, and glutathione peroxidase (GSH-Px), as well as increase the GSH content, in the liver. Liver histopathology also showed that silica hydride reduced the incidence of liver lesions induced by CCl4. The results suggest that silica hydride exhibits potent hepatoprotective effects on CCl4-induced liver damage in mice, likely due to both the increase of antioxidant-defense system activity and the inhibition of lipid peroxidation. [Copyright &y& Elsevier]