Impact of massive ascorbic acid supplementation on alcohol induced oxidative stress in guinea pigs.
ABSTRACT The effects of a mega dose of ascorbic acid (AA) on alcohol induced peroxidative damages were investigated in guinea pigs. In the present study, four groups of male guinea pigs were maintained for 30 days as follows. (1) Control group (1 mg AA/100 g body wt); (2) Ethanol group (1 mg AA/100 g body wt. + 9 g ethanol/kg body wt); (3) AA group (25 mg AA/100 g body wt); (4) AA + ethanol group (25 mg AA/100 g body wt. + 9 g ethanol/kg). Results revealed that alcohol induced significant lipid peroxidation, since the lipid peroxidation products malondialdehyde (MDA), hydroperoxides and conjugated dienes were elevated. The activities of scavenging enzymes superoxide dismutase (SOD), catalase were reduced. However, supplementation of AA along with alcohol reduced the lipid peroxidation products in the liver and enhanced the activities of scavenging enzymes. Activities of glutathione peroxidase and reductase were also greater in guinea pigs given alcohol + AA in comparison with those given alcohol alone. Administration of ascorbic acid also reduced the activity of gamma-glutamyl transpeptidase (GGT), the marker enzyme of alcohol induced toxicity. The vitamin E level, which was reduced by alcohol intake, was raised by the co-administration of AA and alcohol. These studies suggest that a mega dose of AA helps in the prevention of alcohol induced oxidative stress by enhancing the antioxidant capacity and also by reducing the lipid peroxidation products.
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ABSTRACT: Alcohol consumption increases the small intestinal bacterial overgrowth (SIBO) and intestinal permeability of endotoxin. The endotoxin mediated inflammatory signalling plays a major role in alcoholic liver fibrosis. We evaluated the effect of ascorbic acid (AA), silymarin and alcohol abstention on the alcohol induced endotoxemia and NF-κB activation cascade pathway in guinea pigs (Cavia porcellus). Guinea pigs were administered ethanol at a daily dose of 4g/kg b.wt for 90days. After 90days, ethanol administration was stopped. The ethanol treated animals were divided into abstention, silymarin (250mg/kg b.wt) and AA (250mg/kg b.wt) supplemented groups and maintained for 30days. The SIBO, intestinal permeability and endotoxin were significantly increased in the ethanol group. The mRNA expressions of intestinal proteins claudin, occludin and zona occludens-1 were significantly decreased in ethanol group. The mRNA levels of inflammatory receptors, activity of IKKβ and the protein expressions of phospho-IκBα, NF-κB, TNF-α, TGF-β1 and IL-6 were also altered in ethanol group. The expressions of fibrosis markers α-SMA, α1 (I) collagen and Sirius red staining in liver revealed the induction of fibrosis. But the supplementation of AA could induce greater reduction of ethanol induced SIBO, intestinal barrier defects, NF-κB activation and liver fibrosis than silymarin. The possible mechanism may be the inhibitory effect of AA on SIBO, intestinal barrier defect and IKKβ, which decreased the activation of NF-κB and synthesis of cytokines. This might have led to suppression of HSCs activation and liver fibrosis.Toxicology and Applied Pharmacology 11/2013; · 3.98 Impact Factor
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ABSTRACT: To directly examine the contribution of vitamin C to the antioxidant potential of fruits and vegetables, the antioxidant effect of orange juice consumption (8 and 16 fl. oz.) was compared to the antioxidant effect of supplemental vitamin C (dosage equivalent to that supplied by 8 fl. oz. of orange juice). Subjects (n = 11; 28.6 +/- 2.1 years) received each treatment in a 3 x 3 randomized crossover design, and each two-week treatment was preceded by a two-week washout. During the entire trial, subjects restricted fruit and vegetable consumption to < or =3 servings per day except the vitamin C-rich foods (items containing >20 mg/serving), which were restricted to < or =3 servings per week. A fasting blood sample was collected at the end of each washout and each treatment period. Following washouts, plasma vitamin C and lipid peroxidation (plasma TBARS) were similar by treatment group and averaged 25.4 +/- 3.6 micromol/L and 3.82 +/- 0.10 nmol/mL respectively. Plasma vitamin C concentrations were similar following each treatment period, 37.9 +/- 8.1, 45.8 +/- 9.4, and 38.3 +/- 12.4 micromol/L for the 8 and 16 fl. oz. orange juice treatments and the supplement treatment, respectively. All intervention treatments reduced plasma TBARS as compared to pretreatment values: -47% (p = 0.013), -40% (p = 0.083), and -46% (p = 0.015) for the 8 and 16 fl. oz. orange juice treatments and supplement treatment respectively. These data indicate that the regular consumption of 8 fl. oz. orange juice or supplemental vitamin C ( approximately 70 mg/day) effectively reduced a marker of lipid peroxidation in plasma.Journal of the American College of Nutrition 12/2003; 22(6):519-23. · 1.74 Impact Factor
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ABSTRACT: Leejung-tang (LJT, Rechu-to in Japanese and Lizhong-tang in Chinese) is an oriental traditional traditional herbal formula. LJT has been used for treatment of gastrointestinal disorders in Korea, Japan, and China for a long time. In present study, we investigated the protective effects of LJT against absolute ethanol induced gastric injuries. Rats in the control group were given PBS orally (5 mL/kg body weight) as the vehicle, and the absolute-ethanol group (EtOH group) received absolute ethanol (5 mL/kg body weight) by oral gavage. Rats in the positive control group were given omeprazole orally (50 mg/kg body weight) 2 h prior to the administration of absolute ethanol. The treatment groups received LJT (400 mg/kg body weight) 2 h prior to absolute ethanol administration. All rats were sacrificed 1 h after receiving the ethanol treatment. The stomach was excised for macroscopic examination and biochemical analysis. The administration of LJT protected gastric mucosa against ethanol-induced acute gastric injury, including hemorrhage and hyperemia. LJT reduced the increase in lipid peroxidation in ethanol-induced acute gastric lesions. LJT increased GSH content and activities of the antioxidant enzymes, catalase, glutathione-S-transferase, glutathione reductase, glutathione peroxidase, and superoxide dismutase. These results indicate that LJT protects gastric mucosa against ethanol-induced acute gastric injury by increasing their antioxidant content. We suggest that LJT can be developed as an effective drug for the treatment of acute gastric injury.African Journal of Traditional, Complementary and Alternative Medicines 01/2012; 10(2):324-30. · 0.52 Impact Factor