Ameliorative role of conjugated linolenic acid isomers against oxidative DNA damage induced by sodium arsenite in rat model

The present study was undertaken to evaluate the ameliorative role of α-eleostearic acid and punicic acid, isomers of conjugated linolenic (CLnA) acid, against oxidative stress induced DNA damage. Male albino rats were divided into six groups. Group 1 and 2 were normal control and sodium arsenite treated (Sa; 10 mg/kg BW) control respectively. Group 3–6 were orally treated with different doses of two fatty acids (0.5% and 1.0% of total lipid given for each isomer) along with sodium arsenite (Sa; 10 mg/kg BW). Comet assay of blood leukocytes showed that administration of CLnA reduced DNA damage significantly (P < 0.05) which was determined by tail DNA percent and olive tail moment. Results showed that activity of antioxidant enzymes viz. catalase, superoxide dismutase (SOD), glutathione peroxidase (GPx) and reduced glutathione (GSH) in plasma, liver and erythrocyte lysate decreased and activity of nitric oxide synthase in plasma and liver increased significantly due to oxidative stress generated by sodium arsenite. Administration of CLnA isomers restored all the altered parameters and also reduced lipid peroxidation and leakage of transaminase enzymes from liver to blood due to liver injury. α-Eleostearic acid was more efficient antioxidant than punicic acid against oxidative DNA damage.     

Inhibitory effect of eugenol on non-enzymatic lipid peroxidation in rat liver mitochondria.

The anti-peroxidative activity of eugenol on Fe(2+)-ascorbate- and Fe(2+)-H2O2-induced lipid peroxidation was studied using rat liver mitochondria. Eugenol inhibited thiobarbituric acid reactive substance (TBARS) formation induced by both the systems in addition to oxygen uptake and mitochondrial swelling induced by Fe(2+)-ascorbate. Time course studies on TBARS formation indicated the ability of eugenol to inhibit initiation and propagation reactions. There was no measurable chemical modification of eugenol during the course of mitochondrial peroxidation by both the systems. Mitochondrial peroxidation by Fe(2+)-H2O2 was inhibited by hydroxyl radical (OH) scavengers like mannitol, benzoate, formate and dimethyl sulfoxide apart from eugenol. The OH scavenging ability of eugenol was evident from its inhibitory effect on OH-mediated deoxyribose degradation. The second-order rate constant for the reaction of OH with eugenol was about 4.8 x 10(10) M-1 sec-1. Eugenol reduced Fe3+ ions and Fe3+ chelated to citrate or ADP but it did not exhibit pro-oxidant activity in OH-mediated deoxyribose degradation. Incubation of mitochondria with eugenol resulted in the uptake of small but significant quantities of eugenol which inhibited subsequent lipid peroxidation by acting as a chain breaking antioxidant.     

Aqueous extract of Artemisia iwayomogi Kitamura attenuates cholestatic liver fibrosis in a rat model of bile duct ligation

Cholestatic liver fibrosis, characterized by excessive accumulation of extracellular matrix (ECM) proteins, is associated with bile acid-induced oxidative stress and lipid peroxidation. We evaluated the therapeutic or protective effect of an aqueous extract of Artemisia iwayomogi Kitamura (WAI) in a rat bile duct ligation (BDL)-induced hepatic fibrogenesis model. After BDL, rats were treated once daily with 25 or 50 mg/kg of WAI for 2 weeks. The serum bilirubin, aspartate transaminase, alanine transaminase, malondialdehyde, and liver hydroxyproline levels were drastically increased in the BDL group. WAI administration significantly reduced these markers and restored BDL-induced depletion of glutathione content and glutathione peroxidase activity. Cholestatic liver injury and collagen deposition were markedly attenuated by WAI treatment, and these changes were paralleled by significantly suppressed gene and protein expression of fibrogenic factors, including hepatic alphasmooth muscle actin, platelet-derived growth factor, and transforming growth factor β. Our data suggest that WAI may have antifibrotic properties via both improvement of antioxidant activities and inhibition of ECM protein production in the rat model of BDL.     

Mechanisms underlying the protective effect of eugenol in rats with acute doxorubicin cardiotoxicity

The protective effect of eugenol and its possible mechanisms were investigated in rats with acute doxorubicin cardiotoxicity. Cardiac toxicity was induced by a single intraperitoneal injection of doxorubicin (20 mg/kg). Eugenol treatment (5 mg/kg/day, orally) was started 2 days before doxorubicin administration and continued for five consecutive days. Eugenol significantly reduced the elevated serum creatine kinase and lactate dehydrogenase levels, and restored the electrocardiographic disturbances resulted from doxorubicin administration. Also, eugenol reversed doxorubicin-induced deficits in the antioxidant defense mechanisms, decreased lipid peroxidation and attenuated the elevations in cytosolic Ca²⁺ and nitric oxide levels in cardiac tissue. In addition, doxorubicin-induced cardiac tissue damage observed by histopathological examination was markedly ameliorated with eugenol. Immunohistochemical analysis revealed that eugenol prevented the doxorubicin-induced activation of caspase-3 in cardiomyocytes. The cardioprotective effect afforded by eugenol was not significantly inhibited by prior administration of capsazepine, the transient potential vanilloid receptor-1 antagonist. It was concluded that eugenol, through its antioxidant activity and its ability to reduce cardiac Ca²⁺ accumulation and nitric oxide levels, is a potential candidate to protect against acute doxorubicin cardiotoxicity, a major and dose-limiting clinical problem.     

Preventive effects of a purified extract isolated from Salvia miltiorrhiza enriched with tanshinone I,tanshinone IIA and cryptotanshinone on hepatocyte injury in vitro and in vivo

Salvia miltiorrhiza is traditionally used to treat liver disease in Asia. In this study, we tested the ability of a purified extract of S. miltiorrhiza (PF2401-SF) and its constituents, tanshinone I, tanshinone IIA, and cryptotanshinone, to protect against acute and subacute liver damage induced by carbon tetrachloride by measuring serum transaminase levels, the reduced form of glutathione (GSH), antioxidant enzyme activities, and lipid peroxidation levels in the liver. We also evaluated their ability to protect primary cultured rat hepatocytes from tertiary-butylhydroperoxide (tBH) or d-galactosamine (GalN). PF2401-SF was protective at 50–200 mg/kg per day in acute liver injury and 25–100 mg/kg per day in subacute liver injury. Tanshinone I, tanshinone IIA, and cryptotanshinon (40 μM), inhibited lactate dehydrogenase leakage, GSH depletion, lipid peroxidation and free radical generation in vitro. PF2401-SF and its major constituents, tanshinone I, tanshinone IIA and cryptotanshinone, can protect against liver toxicity in vivo and in vitro due to its antioxidant effects.     

Oxidative stress parameters in rats exposed to fluoride and caffeine

In our experiment, the 1-month effects of caffeine (Caff) and fluoride (F) administered separately and together on nitric oxide and total antioxidant status in serum, brain, liver and kidney of rats were investigated. Also, the influence of caffeine on fluoride excretion with urine was studied. Thirty adult male Wistar rats were divided into five equal groups of six each: (I) controls drinking tap water; (II) controls drinking tap water and receiving intragastrically 0.5 ml of tap water; (III) animals receiving 25 mg F/L in drinking water; (IV) animals receiving 4.7 mg Caff/kg bw/day; (V) animals receiving 25 mg F/L in drinking water and 4.7 mg Caff/kg bw/day. The applied fluoride caused increase of nitric oxide level (NO), intensified lipid peroxidation (TBARS) and decreased total antioxidant status in serum (TAS), brain, kidney and liver. Caffeine administered intragastrically, as an antioxidant, was relatively efficient in alleviating these adverse effects of F. In rats treated only with fluoride the F excretion in urine significantly increased in an exposure-time dependent-manner and did not change both in rats treated with Caff and co-exposed to Caff and F.     

Methiocarb-induced oxidative damage following subacute exposure and the protective effects of vitamin E and taurine in rats

Methiocarb, is used worldwide in agriculture and health programs. Besides its advantages in the agriculture, it causes several toxic effects. In this study, we aimed to investigate subacute effects of methiocarb on lipid peroxidation, reduced glutathione (GSH), antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and glutathione reductase (GSH-Rd) and histopathological changes in rat tissues. Moreover, we examined the possible protective effects of vitamin E and taurine on methiocarb-induced oxidative damage in rat tissues. Rats were randomly divided into six groups as follows; I-control group; II-methiocarb group; III-vitamin E group; IV-vitamin E + methiocarb group; V-taurine group and VI-taurine + methiocarb group. Methiocarb significantly increased lipid peroxidation in liver and kidney when compared to control groups. Levels of GSH and activities of SOD, CAT and GSH-Px were found to be decreased, while GSH-Rd remained unchanged in rat liver and kidney treated with methiocarb. Pretreatment of vitamin E and taurine resulted in a significant decrease on lipid peroxidation, alleviating effects on GSH and antioxidant enzymes. The degenerative histological changes were less in liver than kidney of rats treated with methiocarb. Pretreatment of vitamin E and taurine showed a protective effect on the histological changes in kidney comparing to the liver of rats treated with methiocarb.     

Influence of naringenin on oxytetracycline mediated oxidative damage in rat liver

Naringenin is a naturally occurring citrus flavanone, which has been reported to have a wide range of pharmacological properties. The present work was carried out to evaluate the effect of naringenin on antioxidant and lipid peroxidation status in liver of oxytetracycline-intoxicated rats. Intraperitonial administration of oxytetracycline 200 mg/kg for 15 days resulted a significant elevation in serum hepatospecific markers such as aspartate transaminase, alanine transaminase, alkaline phosphatase, lactate dehydrogenase, and bilirubin and the levels of lipid peroxidation markers (thiobarbituric acid reactive substances (TBARS) and lipid hydroperoxides) in liver. Oxytetracycline also caused a significant reduction in the activities of superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione (GSH), vitamin C and vitamin E in liver. Oral administration of naringenin (50 mg/kg b.w.t.) with oxytetracycline significantly decreased the activities of serum aspartate transaminase, alanine transaminase, alkaline phosphatase, lactate dehydrogenase and the levels of bilirubin along with significant decrease in the levels of lipid peroxidation markers in the liver. In addition, naringenin significantly increased the activities of superoxide dismutase, catalase and GSH peroxidase as well as the level of GSH, vitamin C and vitamin E in liver of the oxytetracycline-treated rats. Our results demonstrate that naringenin exhibited antioxidant property and decrease the lipid peroxidation against oxytetracycline-induced oxidative stress in liver.     

Protective effect of Artemisia afra Jacq. on isoproterenol-induced myocardial injury in Wistar rats

Artemisiaafra Jacq. ex Willd. is a widely used medicinal plant in South Africa for the treatment of various diseases. In this study, the effect of the herb on isoproterenol (ISO)-induced myocardial injury in rats was investigated. Pretreatment with the aqueous leaf extract of the plant at 100 and 200 mg/kg body weight for 30 days prevented the elevation of serum marker enzymes namely lactate dehydrogenase (LDH), aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP) in myocardial injured rats. ISO-induced animals exhibited decreased levels of glutathione reductase (GR), glutathione peroxides (GPx), superoxide dismutase (SOD) and glutathione (GSH) in the heart, which were restored to near normal levels following treatment with the herb. The extract also attenuated lipid peroxidation (LPO) in the heart and improved the imbalance in lipid profile caused by ISO. The effect was more prominent at 200 mg/kg body weight. These findings revealed the cardioprotective effect of A. afra against isoproterenol-induced myocardial injury.     

Effect of chitobiose and chitotriose on carbon tetrachloride-induced acute hepatotoxicity in rats

The purpose of the present study was to examine whether chitobiose and chitotriose can protect rats from CCl4-induced hepatic toxicity when given orally. We studied the effects of the 2 chitooligosaccharides given orally to rats on the acute hepatotoxicity induced by CCl4-dependent lipid peroxidation. The increase in the sum of malondialdehyde and 4-hydroxy-2-alkenals, a marker of lipid peroxidation, in both plasma and liver of CCl4-treated rats was suppressed by oral administration of chitobiose or chitotriose. The elevation in the levels of plasma aspartate transaminase and alanine transaminase activities, markers of hepatic injury, induced by CCl4 intoxication was also counteracted by oral administration of either chitooligosaccharide. The results indicate that chitobiose and chitotriose have the ability to exert a protective action against CCl4-induced acute hepatoxicity, probably by their antioxidant activity.     

Silymarin modulates the oxidant-antioxidant imbalance during diethylnitrosamine induced oxidative stress in rats

Oxidative stress is a common mechanism contributing to initiation and progression of hepatic damage in a variety of liver disorders. Hence, there is a great demand for the development of agents with potent antioxidant effect. The aim of the present investigation is to evaluate the efficacy of silymarin as a hepatoprotective and an antioxidant against diethylnitrosamine induced hepatocellular damage. Single intraperitoneal administration of diethylnitrosamine (200 mg/kg) to rats resulted in significantly elevated levels of serum aspartate transaminase (AST) and alanine transaminase (ALT), which is indicative of hepatocellular damage. Diethylnitrosamine induced oxidative stress was confirmed by elevated levels of lipid peroxidation and decreased levels of superoxide dismutase (SOD), catalase, glutathione peroxidase, glutathione reductase (GR) and glutathione-S-transferase (GST) in the liver tissue. The status of non-enzymic antioxidants like, vitamin-C, vitamin-E and reduced glutathione (GSH) were also found to be decreased in diethylnitrosamine administered rats. Further, the status of membrane bound ATPases was also altered indicating hepatocellular membrane damage. Posttreatment with the silymarin (50 mg/kg) orally for 30 days significantly reversed the diethylnitrosamine induced alterations in the liver tissue and offered almost complete protection. The results from the present study indicate that silymarin exhibits good hepatoprotective and antioxidant potential against diethylnitrosamine induced hepatocellular damage in rats.     

Combined effects of vitamin C, vitamin E, and sodium selenate supplementation on absolute ethanol-induced injury in various organs of rats

In this study, the effect of combination of vitamin C (ascorbic acid), vitamin E (alpha -tocopherol), and selenium (sodium selenate) on ethanol-induced liver and intestine injury in rats was investigated. The ethanol-induced injury was produced by the administration of 1 ml of absolute ethanol to each rats. Animals received vitamin C (250 mg/kg), vitamin E (250 mg/kg), and sodium selenate (Se) (0.5 mg/kg) for 3 days; 1 h after the final antioxidant administration, they were sacrificed. Lipid peroxidation and glutathione levels, catalase (CAT), lactate dehydrogenase (LDH), superoxide dismutase (SOD), and glutathione peroxidase (GP(x)) activities were determined in liver and intestine tissues. Myeloperoxidase (MPO), aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), gamma-glutamyltransferase (GGT) were determined in liver tissue. Also, CAT activity, urea, creatinine, uric acid, and total lipid levels were determined in serum samples. In the ethanol group, serum urea, creatinine, uric acid, and total lipid levels; liver and intestine LDH; liver MPO, AST, ALP, ALT, and GGT activities; and liver and intestine LPO levels increased, whereas serum CAT activity, liver and intestine GSH levels, and CAT, SOD, and GP(x) activities decreased. On the other hand, treatment with vitamin C, vitamin E, and Se reversed these effects. As a result of these findings, we can say that the combination of vitamin C, vitamin E, and selenium has a protective effect on ethanol-induced changes in lipid peroxidation, glutathione levels, and antioxidant enzyme activities in liver and intestine tissues, and in some serum parameters of rats.     

CGX,a traditional Korean medicine ameliorates concanavalin A-induced acute liver injury

Concanavalin A (Con A)-induced acute liver injury model is well established as a model of T cell-mediated liver injury, in which T cells and NKT cells exert their cytotoxicity towards liver cells. In this study, we investigated the protective effects of CGX, a traditional Korean medicine against Con A-induced liver injury and its underlying mechanisms. After pretreatment with CGX (po, 50, 100 or 200 mg/kg) or distilled water once daily during 7 days, Con A (15 mg/kg) was injected intravenously. Thereafter serum level of AST and ALT, lipid peroxidation and cytokines in the liver tissue, and immune cell population in blood and the spleen were analyzed. CGX treatment reduced serum ALT, AST level in a dose-dependent manner. CGX treatment significantly decreased the lipid peroxidation and glutathione depletion in the liver tissue, and also lowered tissue levels of tumor necrotic factor-α and interferon-γ. CGX treatment attenuated the compositional alteration of Tc, Th, NKT, and B cells in blood as well as in the spleen. These results suggest that CGX has hepatoprotective property against Con A-induced liver injury through antioxidant action and immune regulation.     

Effects of Urtica dioica L. seed on lipid peroxidation,antioxidants and liver pathology in aflatoxin-induced tissue injury in rats

This study was carried out to investigate the hepatoprotective and antioxidant properties of Urtica dioica L. seeds (UDS) extract against aflatoxin (AF)-exposure in rats. The preventive potential and antioxidant capacity of the plant’s extract was evaluated by liver histopathological changes, measuring serum marker enzymes, antioxidant defense systems and lipid peroxidation (Malondialdehyde, MDA) content in some tissues of rats. Eighteen rats were randomly divided into one of three experimental groups: control, AF-treated group and AF+UDS-treated group. Rats in control group were fed with a diet without AF. Rats in AF-treated group and AF+UDS-treated group received approximately 25 μgr of AF/rat/day. AF+UDS groups also received 2 mL of UDS oils/rat/day by gavage for 90 days. Administration of UDS extract restored the AF-induced imbalance between MDA and antioxidant system towards near normal particularly in liver. Hepatoprotection by UDS is further substantiated by the almost normal histologic findings in AF+UDS-treated group as against degenerative changes in the AF-treated rats. It is concluded that UDS has a hepatoprotective effect in rats with aflatoxicosis, probably acting by promoting the antioxidative defense systems.     

Antioxidant activity and protective effect of Turnera ulmifolia Linn. var. elegans against carbon tetrachloride-induced oxidative damage in rats

The present study aimed to determine whether the leaves of Turnera ulmifolia Linn. var. elegans extract exert significant antioxidant activity. The antioxidant activity of its hydroethanolic extract (HEETU) was evaluated by assessing (a) its radical scavenging ability in vitro, and (b) its in vivo effect on lipid peroxidation and antioxidant enzyme activities. The in vitro antioxidant assay (DPPH) clearly supported HEETU free radical scavenging potential. Moreover, glutathione content and antioxidant enzyme activities (glutathione peroxidase, superoxide dismutase and catalase) were significantly enhanced in CCl₄-treated rats due to oral HEETU-treatment (500 mg/kg b.w.) over 7 and 21 days. In addition, an improvement was observed in lipid peroxidation and serum biochemical parameters (aspartate aminotransferase and alanine aminotransferase), indicating a protective effect against CCl₄-induced liver injuries, confirmed by histopathological studies. The HEETU effect was comparable to the standard drug Legalon® (50 mg/kg b.w.) under the same experimental condition. Quantitative analysis of the HPLC extract revealed the presence of flavonoids, wich mediate the effects of antioxidant and oxidative stress. In conclusion, extract components exhibit antioxidant and hepatoprotective activities in vitro and in vivo.     

Insights antifibrotic mechanism of methyl palmitate: impact on nuclear factor kappa B and proinflammatory cytokines

Fibrosis accompanies most chronic liver disorders and is a major factor contributing to hepatic failure. Therefore, the need for an effective treatment is evident. The present study was designed to assess the potential antifibrotic effect of MP and whether MP can attenuate the severity of oxidative stress and inflammatory response in chronic liver injury. Male albino rats were treated with either CCl₄ (1 ml/kg, twice a week) and/or MP (300 mg/kg, three times a week) for six weeks. CCl₄-intoxication significantly increased liver weight, serum aminotransferases, total cholesterol and triglycerides while decreased albumin level and these effects were prevented by co-treatment with MP. As indicators of oxidative stress, CCl₄-intoxication caused significant glutathione depletion and lipid peroxidation while MP co-treatment preserved them within normal values. As markers of fibrosis, hydroxyproline content and α-SMA expression increased markedly in the CCl₄ group and MP prevented these alterations. Histopathological examination by both light and electron microscope further confirmed the protective efficacy of MP. To elucidate the antifibrotic mechanisms of MP, the expression of NF-κB, iNOS and COX-2 and the tissue levels of TNF-α and nitric oxide were assessed; CCl₄ increased the expression of NF-κB and all downstream inflammatory cascade while MP co-treatment inhibited them. Collectively these findings indicate that MP possesses a potent antifibrotic effect which may be partly a consequence of its antioxidant and anti-inflammatory properties.     

Eugenol with antioxidant activity inhibits MMP-9 related to metastasis in human fibrosarcoma cells

The oxidative damage of lipid, protein and DNA is known to be involved in chronic inflammation as well as metastasis. It has been highlighted for searching natural compounds without toxicity to prevent development of these diseases. Thus, it was investigated whether eugenol can inhibit matrix metalloproteinase (MMP) expression and activity as well as antioxidant effect. Eugenol was contained as a major ingredient in herbs such as clove and Magnoliae Flos. The direct scavenging effects of eugenol on DPPH radical, hydrogen peroxide, reducing power, lipid peroxidation and genomic DNA damage related to oxidative stress were evaluated in cell free system. It was observed that eugenol specifically exhibited higher inhibitory effect on hydrogen peroxide than other reactive oxygen species, and also blocked DNA oxidation and lipid peroxidation induced by hydroxyl radical. In addition, the inhibitory effects of eugenol on the activity and expression of MMP-9 activity related to metastasis were determined using gelatin zymography and western-blot. The data showed that it inhibited MMP-9 activities in PMA-stimulated HT1080 cells. Furthermore, it was found that eugenol exerts inhibitory effects on MMP-9 via inactivation of ERK. Therefore, these results suggest that eugenol could be available as an excellent agent for prevention of metastasis related to oxidative stress.     

Evaluation of the potential protective effects of ad libitum black grape juice against liver oxidative damage in whole-body acute X-irradiated rats

Aims

The aim of this study was to evaluate the potential protective effects of ad libitum black grape (Vitis labrusca) juice against liver oxidative damage in whole-body acute X-irradiated rats.

Main methods

Animals were fed ad libitum and drank voluntarily black grape juice or placebo (isocaloric glucose and fructose solution) for 6 days before and 15 days following a 6 Gy X-irradiation from a 200 kV machine.

Key findings

Irradiated animals receiving placebo showed a significant increase in the concentration of thiobarbituric acid-reactive substances (TBARS), a marker of lipid peroxidation, as well as a significant decrease in both Cu/Zn superoxide dismutase (Cu/ZnSOD) and glutathione peroxidase (GPx) activity and reduced glutathione concentration (GSH). Black grape juice supplementation resulted in a reversal of lipid peroxidation, Cu/ZnSOD activity, and GSH concentration, towards values not significantly differing from those in non-irradiated, placebo-supplemented rats. Poly(ADP-ribose) polymerase (PARP-1) and Cu/ZnSOD changes in protein expression were observed for irradiated rats. No change in p53 expression or DNA fragmentation was found.

Significance

Ad libitum black grape juice intake is able to restore the liver primary antioxidant system against adverse effects due to whole-body acute X-irradiation in rats after 15 days post-irradiation. The results support using antioxidant supplements as a preventive tool against radiation-induced harm.     

Regulation of paraoxonase 1 (PON1) in PCB 126-exposed male Sprague Dawley rats

3,3′,4,4′,5-Pentachlorobiphenyl (PCB 126), an aryl hydrocarbon receptor (AhR) agonist and most potent dioxin-like PCB congener, significantly alters gene expression, lipid metabolism, and oxidative stress in the liver. PON1, an antioxidant and anti-atherogenic enzyme, is produced in the liver and secreted into the blood where it is incorporated into high density lipoprotein (HDL) and protects LDL and cellular membranes against lipid peroxidation. To explore the regulation of PON1, male Sprague-Dawley rats were treated with ip injections of corn oil or 1 μmol/kg or 5 μmol/kg PCB 126 and euthanized up to two weeks afterwards. Serum total and HDL-cholesterol were increased by low dose and decreased by high dose exposure, while LDL-cholesterol was unchanged. PCB 126 significantly increased hepatic PON1 gene expression and liver and serum PON1 activities. Liver and serum thiobarbituric acid reactive substances levels were not elevated except for high dose and long exposure times. Serum antioxidant capacity was unchanged across all exposure doses and time points. This study, the first describing the regulation of gene expression of PON1 by a PCB congener, raises interesting questions whether elevated PON1 is able to ameliorate PCB 126-induced lipid peroxidation and whether serum PON1 levels may serve as a new biomarker of exposure to dioxin-like compounds.     

Hepatoprotective and antioxidant effects of gallic acid in paracetamol‐induced liver damage in mice

Objectives The aim of this research paper was to investigate the hepatoprotective and antioxidant effects of gallic acid in paracetamol‐induced liver damage in mice. Methods In the present study, the hepatoprotective and antioxidant effects of gallic acid were evaluated against paracetamol‐induced hepatotoxicity in mice and compared with the silymarin, a standard hepatoprotective drug. The mice received a single dose of paracetamol (900 mg/kg body weight i.p.). Gallic acid (100 mg/kg body weight i.p.) and silymarin (25 mg/kg body weight i.p.) were administered 30 min after the injection of paracetamol. After 4 h, liver marker enzymes (aspartate transaminase, alanine transaminase and alkaline phosphatase) and inflammatory mediator tumour necrosis factor‐alpha (TNF‐α) were estimated in serum, while the lipid peroxidation and antioxidant status (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione‐S‐transferase and glutathione) were determined in liver homogenate of the control and experimental mice. Key findings Increased activities of liver marker enzymes and elevated TNF‐α and lipid peroxidation levels were observed in mice exposed to paracetamol (P < 0.05), whereas the antioxidant status was found to be depleted (P < 0.05) when compared with the control group. However gallic acid treatment (100 mg/kg body weight i.p.) significantly reverses (P < 0.05) the above changes by its antioxidant action compared to the control group as observed in the paracetamol‐challenged mice. Conclusions The results clearly demonstrate that gallic acid possesses promising hepatoprotective effects.