Effect of sweet grass extract against oxidative stress in rat liver and serum

Overview of the Antioxidant and Anti-Inflammatory Activities of Selected Plant Compounds and Their Metal Ions Complexes

Numerous plant compounds and their metal-ion complexes exert antioxidative, anti-inflammatory, anticancer, and other beneficial effects. This review highlights the different bioactivities of flavonoids, chromones, and coumarins and their metal-ions complexes due to different structural characteristics. In addition to insight into the most studied antioxidative properties of these compounds, the first part of the review provides a comprehensive overview of exogenous and endogenous sources of reactive oxygen and nitrogen species, oxidative stress-mediated damages of lipids and proteins, and on protective roles of antioxidant defense systems, including plant-derived antioxidants. Additionally, the review covers the anti-inflammatory and antimicrobial activities of flavonoids, chromones, coumarins and their metal-ion complexes which support its application in medicine, pharmacy, and cosmetology.

Changes in the Lipid Composition of Biological Membranes under the Influence of Endogenous and Exogenous Factors

Quantitative and qualitative assessments of cell membrane components are essential for the accurate interpretation of processes occurring in biological membranes. Changes in the structure and function of cell membrane components have been linked to oxidative stress. Oxidative stress induced by chronic ethanol consumption or cancer transformation has been implicated in changing the levels of phospholipids and fatty acids in the cell membrane. In this study, we used high-performance liquid chromatography to quantitate the effects of alcohol and malignant transformation on membrane components, namely phospholipids and free fatty acids. Ethanol increased the phospholipid levels. Moreover, the process of malignant transformation was accompanied by increased levels of phospholipids and arachidonic acid as well as decreased levels of linoleic acid and α-linolenic acid. Thus, these oxidative stress-inducing conditions that cause variations in the cellular composition affect the actions of the cell membrane and cell function.

Dietary supplementation of Thai black rice bran extract and yeast beta-glucan protects the dextran sodium sulphate mediated colitis induced rat

The present study was employed to evaluate the impact of black rice bran (RB) extract, and yeast β-glucan (YBG) supplementation on a dextran sodium sulfate (DSS)-induced colitis rat model.

Sweet grass protection against oxidative stress formation in the rat brain

The aims of this study were to investigate the influences of sweet grass on chronic ethanol-induced oxidative stress in the rat brain. Chronic ethanol intoxication decreased activities and antioxidant levels resulting in enhanced lipid peroxidation. Administration of sweet grass solution to ethanol-intoxicated rats partially normalized the activity activities of Cu,Zn-superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase, as well as levels of reduced glutathione and vitamins C, E, and A. Sweet grass also protected unsaturated fatty acids (arachidonic and docosahexaenoic) from oxidations and decreased levels of lipid peroxidation products: 4-hydroxynonenal, isoprostanes, and neuroprostanes. The present in vivo study confirms previous in vitro data demonstrating the bioactivity of sweet grass and suggests a possible role for sweet grass in human health protection from deleterious consequences associated with oxidative stress formation.

Xanthohumol, a prenylated flavonoid from hops (Humulus lupulus L.), protects rat tissues against oxidative damage after acute ethanol administration

Ethanol-mediated free radical generation is directly involved in alcoholic liver disease. In addition, chronic alcohol bingeing also induces pathological changes and dysfunction in multi-organs. In the present study, the protective effect of xanthohumol (XN) on ethanol-induced damage was evaluated by determining antioxidative parameters and stress oxidative markers in liver, kidney, lung, heart and brain of rats. An acute treatment (4 g/kg b.w.) of ethanol resulted in the depletion of superoxide dismutase, catalase and glutathione S-transferase activities and reduced glutathione content. This effect was accompanied by the increased activity of tissue damage marker enzymes (glutamate oxaloacetate transaminase, glutamate pyruvate transaminase and lactate dehydrogenase) and a significant increase in lipid peroxidation and hydrogen peroxide concentrations. Pre-treatment with XN protected rat tissues from ethanol-induced oxidative imbalance and partially mitigated the levels to nearly normal levels in all tissues checked. This effect was dose dependent, suggesting that XN reduces stress oxidative and protects rat tissues from alcohol-induced injury.

Prevention of nonalcoholic steatohepatitis in rats by two manganese-salen complexes

BACKGROUND

Nonalcoholic steatohepatitis (NASH), a progressive stage of nonalcoholic fatty liver disease (NAFLD), is characterized by steatosis with inflammation. Investigations have suggested that oxidative stress may play an important role in the progress of NAFLD to NASH. To provide further insights into beneficial effects of antioxidants in NASH prevention, we employed two manganese-superoxide dismutase/catalase mimetics, manganese N,N`-bis(salicyldene) ethylene diamine chloride (EUK-8) and manganese-3-methoxy N,N`-bis(salicyldene)ethylenediamine chloride (EUK-134), as two salen representatives and vitamin C as the standard antioxidant.

METHODS

Experimental NASH was induced in Male N-Mary rats by feeding a methionine/choline-deficient (MCD) diet to rats for 10 weeks. The rats (n = 5, 30 mg/kg/day) were randomly assigned to receive vitamin C, EUK-8, EUK-134 or vehicle orally.

RESULTS

Administration of salens together with the MCD diet reduced the serum aminotransferases, glutathione transferase and alkaline phosphatase, cholesterol, and LDL contents. In addition, the EUK-8 and EUK-134 improved NASH pathological features in liver of MCD-fed rats.

CONCLUSION

EUK-8 and EUK-134 supplementation reduces NASH-induced abnormalities, pointing out that antioxidant strategy could be beneficial for prevention of NASH.

Resveratrol mitigate structural changes and hepatic stellate cell activation in N'-nitrosodimethylamine-induced liver fibrosis via restraining oxidative damage

Resveratrol, a polyphenol, found in skin of red grapes, peanuts and berries possesses anti-inflammatory, anti-carcinogenic and lipid modulation properties. Here, we demonstrate in vivo antifibrotic activity of resveratrol in a mammalian model, wherein hepatic fibrosis was induced by N'-nitrosodimethylamine (NDMA) administration. Apart from being a potent hepatotoxin, NDMA is a known mutagen and carcinogen, as well. To induce hepatic fibrosis, rats were administered NDMA (i.p.) in 10mg/kgb.wt thrice/week for 21 days. Another group of animals received resveratrol supplement (10mg/kgb.wt) subsequent to NDMA administration and were sacrificed weekly. The changes in selected biomarkers were monitored to compare profibrotic effects of NDMA and antifibrotic activity of resveratrol. The selected biomarkers were: sera transaminases, ALP, bilirubin, liver glycogen, LPO, SOD, protein carbonyl content, ATPases (Ca(2+), Mg(2+), Na(+)/K(+)) and hydroxyproline/collagen content. Alterations in liver architecture were assessed by H&E, Masson's trichrome and reticulin staining of liver biopsies. Immuno-histochemistry and immunoblotting were employed to examine expression of α-SMA. Our results demonstrate that during NDMA-induced liver fibrosis transaminases, ALP, bilirubin, hydroxyproline and liver collagen increases, while liver glycogen is depleted. The decline in SOD (>65%) and ATPases, which were concomitant with the elevation in MDA and protein carbonyls, strongly indicate oxidative damage. Fibrotic transformation of liver in NDMA-treated rats was verified by histopathology, immuno-histochemistry and immunoblotting data, with the higher expressivity of α-SMA-positive HSCs being most established diagnostic immuno-histochemical marker of HSCs. Resveratrol-supplement refurbished liver architecture by significantly restoring levels of biomarkers of oxidative damage (MDA, SOD, protein carbonyls and membrane-bound ATPases). Therefore, we conclude that antifibrotic effect of resveratrol is due to restrained oxidative damage and down-regulation of α-SMA, which inhibits HSC activation to obstruct liver fibrosis.

Effect of sweet grass (Hierochloe odorata) on the physico-chemical properties of liver cell membranes from rats intoxicated with ethanol

Changes in the composition and physicochemical properties of liver cell membranes due to ethanol intoxication are due mainly to reactive oxygen species (ROS). The destructive action of free radicals can be neutralized by administration of antioxidants. The purpose of this study was to investigate the efficacy of sweet grass on the physicochemical and biochemical properties of the rat liver membrane altered by chronic ethanol intoxication. Qualitative and quantitative composition of phospholipids and proteins in the membrane were determined by HPLC. Ethanol increased phospholipid levels and altered the level of integral proteins as determined by decreased phenylalanine, cysteine and lysine. Ethanol significantly enhanced changes in the surface charge density of the liver cell membranes as determined by electrophoresis. Administration of sweet grass to rats intoxicated with ethanol significantly protects lipids and proteins against oxidative modifications. Therefore, sweet grass protects against some of the deleterious membrane changes associated with ethanol exposure.

Black-currant protection against oxidative stress formation

The aim of this study was to investigate the influence of black-currant juice on chronic ethanol-induced oxidative stress and its consequences in liver, brain, and serum of rats. Data demonstrated that administration of black-currant juice to rats improved antioxidant abilities in the examined tissues as evidenced by measurement of activities of Cu,Zn-superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and glutathione reductase (GSSG-R), as well as levels of glutathione (GSH) and vitamins C, E, and A. Ethanol intoxication produced a decrease in the activities and levels of the antioxidants just listed, and the decrease was accompanied by a reduction in levels of arachidonic acid (AA) and docosahexaenoic acid (DHA). Further results showed enhanced lipid peroxidation as determined by malondialdehyde (MDA), 4-hydroxynonenal (4-HNE), and neuroprostanes and elevated protein levels such as carbonyl groups and dityrosine. Ethanol intoxication altered liver metabolism as evidenced by a decrease in peroxisome proliferator-activated-receptor (PPARα), AMP-dependent protein kinase (AMPK), and nuclear factor kappa B cells (NFκB) and by an increase in tumor necrosis factor (TNF-α) expression. Administration of black-currant juice to ethanol-intoxicated rats exerted an antioxidant response by restoring to normal quantities the antioxidant levels and enzyme activities and prevented lipid and protein oxidative effects. The activities of alanine transaminase and aspartate transaminase, biomarkers of liver damage, returned to normal after black-currant treatment of ethanol-administered animals. In addition, the expression of PPARα, AMPK, TNF-α, and NFκB confirmed the protective effect of the juice. Data thus indicate the extensive antioxidant metabolic effects of black-currant juice that may be beneficial for humans.