Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.3.1.109 (AST)
 6,066 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pressure ulcers (PU) cause morphological and functional alterations in the skin and visceral organs. In this study we investigated the role of oxidative damage in PUs and the probable beneficial effect of beta-glucan treatment against this damage. beta-glucan is known to have immunomodulatory effects. Experiments were carried on Wistar albino rats. PU was induced by applying magnets over steel plates that were implanted under the skin, to compress the skin and cause ischemia where removing the magnets cause reperfusion of the tissue. Within the first 12 h, rats were subjected to 5 cycles of ischemia/reperfusion (I/R), followed by 12 h ischemia. This protocol was repeated for 3 days. In treatment groups, twice a day during reperfusion periods, beta-glucan was either applied locally (25 mg/kg) as an ointment on skin, or administered orally (50 mg/kg) as a gavage. At the end of the experimental periods, tissue samples (skin, liver, kidney, lung, stomach, and ileum) were taken for the measurement of malondialdehyde (MDA)--an index of lipid peroxidation--and glutathione (GSH)--a key antioxidant--levels. Neutrophil infiltration was evaluated by the measurement of tissue myeloperoxidase activity, while collagen contents were measured for the evaluation of tissue fibrosis. Skin tissues were also examined microscopically. Liver and kidney functions were assayed in serum samples. Local treatment with beta-glucan inhibited the increase in MDA and MPO levels and the decrease in GSH in the skin induced by PU, but was less efficient in preventing the damage in visceral organs. However, systemic treatment prevented the damage in the visceral organs. Significant increases in creatinine, BUN, ALT, AST, LDH and collagen levels in PU group were prevented by beta-glucan treatment. The light microscopic examination exhibited significant degenerative changes in dermis and epidermis in the PU group. Tissue injury was decreased especially in the locally treated group. Thus, supplementing geriatric and neurologically impaired patients with adjuvant therapy of beta-glucan may have some benefits for successful therapy and improving quality of life.
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PMID:Pressure ulcer-induced oxidative organ injury is ameliorated by beta-glucan treatment in rats. 1654 2

This investigation elucidates the role of free radicals in acetaminophen (AA)-induced toxicity and the possible protection by resveratrol (RVT). BALB-c mice were injected with a single dose of 900mg/kg AA to induce toxicity, while RVT administred in a dose of 30mg/kg i.p. following AA. Mice were sacrificed 4h after AA injection to determine serum ALT, AST and tumor necrosis factor-alpha (TNF-alpha) levels in blood, and glutathione (GSH), malondialdehyde (MDA) levels, myeloperoxidase (MPO) activity and collagen contents in liver tissues. Formation of reactive oxygen species in hepatic tissue samples was monitored by using chemiluminescence (CL) technique with luminol and lucigenin probe. ALT, AST levels and TNF-alpha were increased significantly after AA treatment, and reduced with RVT. AA caused a significant decrease in GSH levels while MDA levels and MPO activity were increased in liver tissues. On the other hand when RVT administered following AA, depletion of GSH and accumulation of MDA and neutrophil infiltration were reversed back to control. Furthermore increased luminol and lucigenin CL levels in the AA group reduced by RVT treatment. Our results implicate that AA causes oxidative damage in hepatic tissues and RVT, by its potent antioxidant effects protects the liver tissue. These data suggest that RVT may be of therapeutic use in preventing hepatic oxidative injury due to AA toxicity.
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PMID:Protective effects of resveratrol against acetaminophen-induced toxicity in mice. 1659 88

The protective effect of Lygodium flexuosum n-hexane extract against D-galactosamine was evaluated in Wistar rats. In preventive groups extract was administered at 48, 24 and 2h before D-galactosamine intoxication whereas in post-treatment groups extract were administered 2, 24 and 48 h after D-galactosamine intoxication. Rats pre-treated with n-hexane extract at a dose of 200 and 100 mg/kg of Lygodium flexuosum showed a significant prevention of elevated AST, ALT, LDH levels and hepatic malondialdehyde in D-galactosamine treated rats. Hepatic glutathione levels significantly upregulated by the extract treatment in D-galactosamine treated rats. Quantification of histopathological sections supported the preventive action of n-hexane extract of Lygodium flexuosum. Rats treated with the extract at a dose of 200 and 100 mg/kg Lygodium flexuosum after the establishment of D-galactosamine induced liver injury showed complete protection of liver as evidenced from normal AST, ALT and LDH levels, hepatic GSH and MDA levels and also by normal histological index of liver in treated rats. Rats treated with n-hexane extract of Lygodium flexuosum were comparable to that of Silymarin, the standard hepatoprotective drug.
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PMID:Protective effect of Lygodium flexuosum (L.) Sw. (Lygodiaceae) against D-galactosamine induced liver injury in rats. 1679 98

The study was aimed at evaluating the antioxidant activity of alcoholic extract of Cassia siamea Lam. (Fabaceae) flowers. The extract was found to contain a large amount of polyphenols and also exhibited an immense reducing ability. At a concentration of 250 microg/ml, 96% of DPPH radicals and at 500 microg/ml, 42.7, 32.7 and 64.5% of O2-, H2O2 and NO respectively could be scavenged by C. siamea flower extract. The extract also inhibited OH radical induced oxidation of protein (BSA) and LPO in murine hepatic microsomes. The determination of metal chelating capacity of the extract indicated chelating of metal ions (Fe2+) to be a putative mechanism implicated in the inhibition of OH radical-induced BSA oxidation and LPO. C. siamea flower extract also exhibited a significant antioxidant activity in acute oxidative tissue injury animal model constituted by CCl4 induced hepatotoxicity. Oral administration of the extract at a dose of 50-150 mg/kg of body weight significantly protected from CCl4 induced elevation in AST and ALT in the serum, elevation in hepatic LPO, depletion of hepatic GSH and decrease in the activities of hepatic antioxidant enzymes: SOD, CAT and GPX. The extract also protected against histopathological changes produced by CCl4 such as necrosis, fatty changes, ballooning degeneration, etc. The data obtained in the present study suggests that the alcoholic extract of C. siamea flowers have potent antioxidant activity against free radicals, prevent oxidative damage to major biomolecules and afford significant protection against oxidative damage in the liver.
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PMID:Evaluation of antioxidant activity of Cassia siamea flowers. 1684 7

Hesperidin (HDN) is a flavanone glycoside abundantly found in citrus fruits. HDN has been reported to possess significant activities against allergy, haemorrhoids, hormonal disorders and ulcers. Other reported activities include anti-inflammatory, analgesic, antibacterial, antifungal, antiviral, antioxidant and free radical scavenger activity. A potentially important effect of endotoxin is the increased production of reactive oxygen intermediates as O(2)(-), peroxides and nitric oxide. The study reported here show a beneficial effect of HDN in amelioration of endotoxin-induced hepatic dysfunction and oxidative stress in the liver of rats. Hepatotoxicity was induced by administering lipopolysaccharide (LPS), in a single dose of 1mg/kg intraperitoneally to the rats. A marked hepatic dysfunction evident by rise in serum levels of liver enzymes (ALT, AST, ALP) and total bilirubin (p<0.05) was observed. Serum and tissue nitrite levels were also increased. LPS challenge further increased thiobarbituric acid reactive substances (TBARS) levels, whereas glutathione (GSH) content and superoxide dismutase (SOD) activity were decreased in the liver homogenates of the rats showing a marked oxidative stress. HDN administration successfully and dose dependently attenuated these effects of LPS. In conclusion, these findings suggest that HDN attenuates LPS-induced hepatotoxicity possibly by preventing cytotoxic effects of NO and oxygen free radicals.
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PMID:Beneficial effect of hesperidin on lipopolysaccharide-induced hepatotoxicity. 1691 60

The antiangiogenic effect of Lygodium flexuosum extract was evaluated in Wistar rats intoxicated with N-nitrosodiethylamine (NDEA) in preventive and curative models. In preventive groups, NDEA was administered for 20 weeks. Daily doses of L. flexuosumn-hexane extract (200mg/kg) started 1 week before the onset of NDEA intoxication and continued for 20 weeks. In curative animals, NDEA was administered for 20 weeks followed by treatment with the n-hexane extract of L. flexuosum for 28 days. Rats intoxicated with NDEA had elevated levels of serum gamma-GT, AST, ALT, LDH levels and hepatic MDA and decreased levels of hepatic GSH. When treated with L. flexuosum extract had normal levels of gamma-GT, AST, ALT, LDH levels, hepatic MDA and GSH. NDEA administered rat liver showed an overexpressed levels of angiopoietins 1 (Ang-1) and 2 (Ang-2) and its receptor Tie-2 mRNA. L. flexuosum extract treatment significantly (p<or=0.05) reduced the levels of Ang-1 and Ang-2 and Tie-2 in rat livers evidenced by RT-PCR. Immunohistochemical analysis showed that vascular endothelial growth factor (VEGF) was overexpressed and localized around periportal area of liver sections intoxicated with NDEA and its overexpression was effectively reduced by the treatment with L. flexuosum extract. Histopathological observations also substantiated NDEA-induced hepatotoxicity and the effect was significantly (p<or=0.05) reduced by L. flexuosum extract treatment. Thus, L. flexuosum extract at a dose of 200mg/kg effectively reversed the hepatotoxicity induced by N-nitrosodiethylamine in both experimental models.
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PMID:Antiangiogenic effect of Lygodium flexuosum against N-nitrosodiethylamine-induced hepatotoxicity in rats. 1703 75

Cisplatin (CDDP) is a widely used anticancer drug, but at high dose, it can produce undesirable side effects such as hepatotoxicity. Because silymrin has been used to treat liver disorders, the protective effect of silymarin on CDDP-induced hepatotoxicity was evaluated in rats. Hepatotoxicity was determined by changes in serum alanine aminotransferase [ALT] and aspartate aminotransferase [AST], nitric oxide [NO] levels, albumin and calcium levels, and superoxide dismutase [SOD], glutathione peroxidase [GSHPx] activities, glutathione content, malondialdehyde [MDA] and nitric oxide [NO] levels in liver tissue of rats. Male albino rats were divided into four groups, 10 rats in each. In the control group, rats were injected i.p. with 0.2 ml of propylene glycol in saline 75/25 (v/v) for 5 consecutive days [Silymarin was dissolved in 0.2 ml of propylene glycol in saline 75/25 v/v]. The second group were injected with CDDP (7.5 mg /kg, I.P.), whereas animals in the third group were i.p. injected with silymarin at a dose of 100 mg/kg/day for 5 consecutive days. The Fourth group received a daily i.p. injection of silymarin (100 mg/kg/day for 5 days) 1 hr before a single i.p. injection of CDDP (7.5 mg/kg). CDDP hepatotoxicity was manifested biochemically by an increase in serum ALT and AST, elevation of MDA and NO in liver tissues as well as a decrease in GSH and the activities of antioxidant enzymes, including SOD, GSHPx in liver tissues. In addition, marked decrease in serum NO, albumin and calcium levels were observed. Serum ALT, AST, liver NO level, MDA was found to decreased in the combination group in comparison with the CDDP group. The activities of SOD, GSHPx, GSH and serum NO were lower in CDDP group than both the control and CDDP pretreated with silymarin groups. The results obtained suggested that silymarin significantly attenuated the hepatotoxicity as an indirect target of CDDP in an animal model of CDDP-induced nephrotoxicity.
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PMID:Silymarin modulates Cisplatin-induced oxidative stress and hepatotoxicity in rats. 1712 99

The effects of NO on LTC4 generation during hepatic ischemia-reperfusion (I/R) are largely unclear. Sprague-Dawley rats were divided into control, I/R and sodium nitroprusside (SNP, 2.5, 5 and 10 microg/kg/min)+I/R groups. Liver was subjected to I/R injury, saline or SNP administered intravenously. The protein expressions of LTC4 synthesis enzymes including LTC4 synthase (LTC4S), microsomal glutathione-S-transferase (mGST)2 and mGST3 were detected with immunoblotting, the LTC4 synthesis enzymes' activities and LTC4 content were measured by RP-HPLC, the mRNA expressions of inducible nitric oxide synthase (iNOS) and endogenous nitric oxide synthase (eNOS) in liver were measured by RT-PCR. Tissue injuries were assessed by serum ALT and AST and histological changes. Serum NO(2)(-) and liver tissue GSH were also examined. Compared with I/R group, SNP markedly decreased LTC4 content, LTC4S protein and iNOS mRNA levels, and the LTC4 synthesis enzymes' activities (P<0.05), but significantly enhanced eNOS mRNA expression in liver (P<0.05). The decline in serum ALT, AST and NO(2)(-) levels (P<0.05) together with hepatic GSH elevation (P<0.05) in SNP+I/R groups were also observed. LTC4S expression in hepatocytes and sinusoidal endothelial cells in SNP+I/R groups was lower than that in I/R group. But no significant differences in the protein expressions of mGST3 and mGST2 existed between control, I/R and SNP+I/R groups (P>0.05). These results demonstrated that the decline in LTC4 production by SNP treatment during hepatic I/R could be partially resulted from SNP down-regulating the protein expression of LTC4S rather than mGST2 or mGST3 and its inhibiting the LTC4 synthesis enzymes' activities.
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PMID:Sodium nitroprusside decreased leukotriene C4 generation by inhibiting leukotriene C4 synthase expression and activity in hepatic ischemia-reperfusion injured rats. 1719 56

The aim of this study was to investigate the possible protective effects of echinacoside, one of the phenylethanoids isolated from the stems of Cistanches salsa, a Chinese herbal medicine, on the free radical damage of liver caused by carbon tetrachloride in rats. Treatment of rats with carbon tetrachloride produced severe liver injury, as demonstrated by dramatic elevation of serum ALT, AST levels and typical histopathological changes including hepatocyte necrosis or apoptosis, haemorrhage, fatty degeneration, etc. In addition, carbon tetrachloride administration caused oxidative stress in rats, as evidenced by increased reactive oxygen species (ROS) production and MDA concentrations in the liver of rats, along with a remarkable reduction in hepatic SOD activity and GSH content. However, simultaneous treatment with echinacoside (50mg/kg, intraperitoneally) significantly attenuated carbon tetrachloride-induced hepatotoxicity. The results showed that serum ALT, AST levels and hepatic MDA content as well as ROS production were reduced dramatically, and hepatic SOD activity and GSH content were restored remarkably by echinacoside administration, as compared to the carbon tetrachloride-treated rats. Moreover, the histopathological damage of liver and the number of apoptotic hepatocytes were also significantly ameliorated by echinacoside treatment. It is therefore suggested that echinacoside can provide a definite protective effect against acute hepatic injury caused by CCl(4) in rats, which may mainly be associated with its antioxidative effect.
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PMID:Protective effects of echinacoside on carbon tetrachloride-induced hepatotoxicity in rats. 1722 97

Mercury(II) is a highly toxic metal which induces oxidative stress in the body. In this study we aimed to investigate the possible protective effect of Ginkgo biloba (EGb), an antioxidant agent, against experimental mercury toxicity in rat model. Following a single dose of 5mg/kg mercuric chloride (HgCl(2); Hg group) either saline or EGb (150mg/kg) was administered for 5days. After decapitation of the rats trunk blood was obtained and the tissue samples from the brain, lung, liver, and kidney were taken for the determination of malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity and collagen contents. Formation of reactive oxygen species in the tissue samples was monitored by chemiluminescence (CL) technique. BUN, creatinin, ALT, and AST levels and tumor necrosis factor-alpha (TNF-alpha) and lactate dehydrogenase (LDH) activity were assayed in serum samples. The results revealed that HgCl(2) induced oxidative damage caused significant decrease in GSH level, significant increase in MDA level, MPO activity and collagen content of the tissues. Treatment of rats with EGb significantly increased the GSH level and decreased the MDA level, MPO activity, and collagen contents. Similarly, serum ALT, AST and BUN levels, as well as LDH and TNF-alpha, were elevated in the Hg group as compared to control group. On the other hand, EGb treatment reversed all these biochemical indices. Our results implicate that mercury-induced oxidative damage in brain, lung, liver, and kidney tissues protected by G. biloba extract, with its antioxidant effects.
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PMID:Ginkgo biloba extract protects against mercury(II)-induced oxidative tissue damage in rats. 1726 89


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