Selenium modulates β‐cyfluthrin‐induced liver oxidative toxicity in rats

This study was designed to investigate the possibility of β‐cyfluthrin to induce oxidative stress and biochemical perturbations in rat liver and the role of selenium in alleviating its toxic effects. Male Wister rats were randomly divided into four groups of seven each, group I served as control, group II treated with selenium (200 µg/kg BW), group III received β‐cyfluthrin (15 mg/kg BW, 1/25 LD₅₀), and group IV treated with β‐cyfluthrin plus selenium. Rats were orally administered their respective doses daily for 30 days. The administration of β‐cyfluthrin caused elevation in lipid peroxidation (LPO) and reduction in the activities of antioxidant enzymes including catalase (CAT), superoxide dismutase (SOD), glutathione S‐transferase (GST), glutathione peroxidase (GPx), and glutathione reductase (GR). A decrease in reduced glutathione (GSH) content was also observed. Liver aminotransferases (AST and ALT) and alkaline phosphatase (ALP) were decreased, whereas lactate dehydrogenase (LDH) was increased. Selenium in β‐cyfluthrin‐induced liver oxidative injury of the rats modulated LPO, CAT, SOD, GSH, GST, GPx, and GR. Also, liver AST, ALT, ALP, and LDH were maintained near normal level due to selenium treatment. It is concluded that selenium scavenges reactive oxygen species and render a protective effect against β‐cyfluthrin toxicity. © 2013 Wiley Periodicals, Inc. Environ Toxicol 29: 1323–1329, 2014.     

Effect of wastewater intake on antioxidant and marker enzymes of tissue damage in rat tissues: Implications for the use of biochemical markers

In the present study, alteration in antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione-S-transferase (GST) and glutathione peroxidase (GPx) and marker enzymes of tissue damage alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP) with laboratory exposure to wastewaters from Aligarh (AWW) and Saharanpur (SWW) were investigated in rat liver and kidney. Levels of malondialdehyde (MDA), reduced glutathione (GSH) and hydrogen peroxide (H₂O₂) were also determined.A profound enhancement of 5 and 2.5-folds in MDA level was recorded in the liver and kidney respectively as a result of oral administration of SWW to the rats. Exposure to both AWW and SWW resulted in 3–4-fold increase in GR activity and 3-fold increase in SOD and ALT activity in the hepatic tissue compared to control values. Ingestion of AWW and SWW resulted in 3.5-fold rise in renal AST levels whereas AWW caused 75% decline in GST activity in kidney of treated rats.Results indicate that wastewater (AWW/SWW) caused severe damage to renal and hepatic tissues and the effect seems in part to be mediated by suppression of antioxidant system with GR and SOD as potential candidates for hepatic toxicity biomarkers of wastewaters.     

Pectolinarin and Pectolinarigenin of Cirsium setidens Prevent the Hepatic Injury in Rats Caused by D-Galactosamine via an Antioxidant Mechanism

To identify the hepatoprotective component from the leaves of Cirsium setidens (Compositae), the methanolic extract was divided into two fractions, chloroform and butanol fractions, and their hepatoprotective efficacy was evaluated in a rat model of hepatic injury caused by D-galactosamine (GalN). Hepatoprotective activity was measured by the activity of serum aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH). Glutathione metabolism was measured via biochemical parameters such as glutathione (GSH), glutathione reductase (GR), gamma-glutamylcysteine synthetase (GCS), glutathione S-transferase (GST), and superoxide dismutase (SOD) levels. We subjected the butanol fraction, which had higher activity, to column chromatography to yield pectolinarin, which was further hydrolyzed to yield pectolinarigenin. Administration (10, 20 mg/kg, p.o.) of the main flavonoid glycoside component, pectolinarin, and its aglycone, pectolinarigenin, for 2 weeks significantly decreased the activity levels of AST, ALT, ALP and LDH, indicating that the two compounds have hepatoprotective activity. Pectolinarin and pectolinarigenin also increased activity levels of GSH, GR, GCS, and GST, as well as SOD. The significant effect was only seen in SOD activity. This suggests that the two components exhibit hepatoprotective activity mainly via SOD antioxidant mechanism.     

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.     

Amelioration of cyclophosphamide-induced hepatotoxicity by the root extract of Decalepis hamiltonii in mice

Hepatoprotective potential of the aqueous extract of the roots of Decalepis hamiltonii (DHA) against cyclophosphamide (CP)-induced oxidative stress has been investigated in mice. Administration of CP (25 mg/kg b.w., i.p) for 10 days induced hepatic damage as indicated by the serum marker enzymes aspartate and alanine transaminases (AST, ALT), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH). Parallel to these changes CP induced oxidative stress in the liver as evident from the increased lipid peroxidation (LPO), reactive oxygen species (ROS), depletion of glutathione (GSH), and reduced activities of the antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione-S-transferase (GST). Treatment with DHA (50 and 100 mg/kg b.w., po) mitigated the CP-induced oxidative stress. Moreover, expression of genes for the antioxidant enzymes, were down-regulated by CP treatment which was reversed by DHA. Our study shows the DHA protected the liver from toxicity induced by CP and therefore, it could be serve as a safe medicinal supplement during cyclophosphamide chemotherapy.     

Caffeic acid phenethyl ester protects against tamoxifen-induced hepatotoxicity in rats

Tamoxifen (TAM) is widely used in the treatment and prevention of breast cancer. Adverse effects of TAM include hepatotoxicity. Caffeic acid phenethyl ester (CAPE), an active component of propolis, has been used in folk medicine for diverse ailments. In the current study, the protective effects of CAPE against TAM-induced hepatotoxicity in female rats were evaluated. TAM (45 mg/kg/day, i.p., for 10 consecutive days) resulted in an elevation of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP), depletion of liver reduced glutathione (GSH) and accumulation of oxidized glutathione (GSSG) and lipid peroxidation (LPO). Also, TAM treatment resulted in inhibition of hepatic activity of glutathione reductase (GR), glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT). Further, it raised liver tumor necrosis factor-alpha (TNF-α) level and induced histopathological changes. Pretreatment with CAPE (2.84 mg/kg/day; i.p., for 20 consecutive days, starting 10 days before TAM injection) significantly prevented the elevation in serum activity of the assessed enzymes. CAPE significantly inhibited TAM-induced hepatic GSH depletion and GSSG and LPO accumulation. Consistently, CAPE normalized the activity of GR, GPx, SOD and CAT, inhibited the rise in TNF-α and ameliorated the histopathological changes. In conclusion, CAPE protects against TAM-induced hepatotoxicity.     

Piperine as an adjuvant increases the efficacy of curcumin in mitigating benzo(a)pyrene toxicity

In the present study, the antioxidative and anticlastogenic effects of curcumin and piperine separately and in combination have been investigated against benzo(a)pyrene (BaP)-mediated toxicity in mice. Male Swiss albino mice were pretreated with curcumin (100 mg kg(-1) body weight) and piperine (20 mg kg(-1) body weight) separately as well as in combination orally in corn oil for 7 days; and subsequently, after 2 h of pretreatment, BaP was administered orally in corn oil (125 mg kg(-1) body weight). A single dose of BaP in normal mice increased the levels of lipid peroxidation (LPO), protein carbonyl content (PCC), and frequency of bone marrow micronucleated polychromatic erythrocytes (MNPCEs) but decreased significantly the levels of endogenous antioxidants such as superoxide dismutases (SODs), glutathione peroxidase (GPx), glutathione reductase (GR), catalase (CAT) and reduced glutathione (GSH) in the liver. Pretreatments with curcumin and curcumin plus piperine before administration of single dose of BaP significantly decreased the levels of LPO, PCC, and incidence of MNPCEs but elevated the level of GSH and enzyme activities of GPx, GR, SOD, CAT, and glutathione-S-transferase (GST) when compared to the BaP-treated group. The effect of curcumin plus piperine is more pronounced as compared to curcumin in attenuating BaP-induced oxidative insult and clastogenicity.     

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.     

Effects of insecticides fenitrothion,endosulfan and abamectin on antioxidant parameters of isolated rat hepatocytes

Fenitrothion, endosulfan and abamectin are insecticides that affect various organs in humans and animals. The present study was conducted to investigate their cytotoxicity in isolated male rat hepatocytes. The study suggests that incubation of hepatocytes with 10 or 100 μM of each insecticide for 2 h significantly decreased the cell viability. Increased leakage percentage of lactate dehydrogenase (LDH), alanine transaminase (ALT) and aspartate aminotranferase (AST) were detected in hepatocytes due to the same dose of insecticide exposure confirmed membrane damage of hepatocytes. Fenitrothion (100 μM) increased the cellular lipid peroxidation (LPO) levels more than the other insecticides. The activities of the antioxidant enzymes like superoxide dismutase (SOD), glutathione peroxidise (GSH-Px) and glutathione-S-transferase (GST) were decreased by fenitrothion incubation more than endosulfan and abamectin. The same treatment reduced the level of antioxidant glutathione (GSH) and increased the level of LPO. The activities of glutathione-S-transferase (GST) and gamma glutamyl transpeptidase (γ-GT) were more affected by fenitrothion and endosulfan, respectively, indicating an oxidative stress. There was negative correlation coefficient among GSH, GST and γ-GT. A significant correlation was also found between γ-GT and cell viability. The present study revealed that fenitrothion showed varying pathological signs depending on the dose; high dose caused marked damage of isolated hepatocytes in the oxidative and antioxidant parameters. Endosulfan induced cell membrane damage of the hepatocytes more than abamectin and fenitrothion as indicated by increasing the leakage percentages of LDH, ALT, AST and γ-GT. Therefore, hepatotoxicity of insecticides increased in a time and dose-dependent manner and depended on the class of the insecticide.     

Effects of dietary selenium on the oxidative stress and pathological changes in tilapia (Oreochromis niloticus) exposed to a microcystin-producing cyanobacterial water bloom

The present study investigates the role of selenium (Se) supplementation (as sodium selenite) on the oxidative stress and histopathological changes induced by cyanobacterial cells containing microcystins (MCs) in tilapia fish (Oreochromis niloticus). Variation in lipid peroxidation (LPO) levels and carbonyl groups content, reduced glutathione/oxidized glutathione (GSH/GSSG) ratio, and catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR), glutathione peroxidase (GPx) and glutathione S-transferase (GST) activities in liver and kidney of tilapia fish exposed to a single oral dose of 120 μg MC-LR/fish and sacrificed in 24 h, were investigated in the absence and presence of 1.5, 3.0 and 6.0 μg Se/g diet. Results showed a protective role of Se depending on the dose and the biomarker considered. Thus, the lower Se dose made CAT, liver GR and kidney SOD converged to basal values, whereas LPO and liver SOD and GST needed the higher dose. Kidney GR, however, was not protected at any Se dose. Moreover, Se has also shown to have a pro-oxidant effect with increased kidney LPO values and liver and kidney GPx activities in MC-free fish. The microscopic study revealed tissue alterations induced by cyanobacterial cells in the liver, kidney, heart and gastrointestinal tract that were ameliorated by the highest Se dose assayed. The level of Se supplementation must be therefore carefully selected to provide beneficial effects and to avoid potential negative consequences.     

Repeated acetaminophen dosing in rats: adaptation of hepatic antioxidant system

Repeated dosing of acetaminophen (paracetamol) to rats is reported to decrease their sensitivity to its hepatotoxic effects, which are associated with oxidative stress and glutathione depletion. We determined if repeated acetaminophen dosing produced adaptive response of key antioxidant system enzymes. Male rats (Sprague-Dawley, 10 weeks) were given 800, 1200, or 1600 mg/kg/day acetaminophen by oral gavage for 4 days. Liver was assayed for oxidative stress and antioxidant markers: malondialdehyde (MDA), thiobarbituric acid reactive substance (TBARS), total antioxidant status (TAS), glutathione (GSH), glutathione reductase (GR), glutathione peroxidase (GPx), glucose-6-phosphate dehydrogenase (G6PD), catalase (CAT), and superoxide dismutase (SOD), and alanine transaminase (ALT) as a marker of hepatocellular injury. Acetaminophen at 1200/1600 mg/kg decreased GSH 26/47%, GPx 21/26%, CAT 35/28%, SOD 21/12%; and TAS 28/18% (correlated with CAT, r=0.91; SOD, r=0.66; GPx, r=0.45). Despite antioxidant deficiencies, and no TBARS change, MDA decreased 26%/33%/37% at 800/1200/1600 mg/kg, which correlated with increased GR (61%/62%/76%, r=0.77) and G6PD (130%/110%/190%, r=0.78). Both MDA (r=0.68) and G6PD (r=0.71) correlated with hepatic ALT, which decreased 27%/43%/48%, respectively. Resistance to acetaminophen hepatotoxicity produced by repeated exposure is partially attributable to upregulation of hepatic G6PD and GR activity as an adaptive and protective response to oxidative stress and glutathione depletion.     

Protective effects of Phyllanthus amarus aqueous extract against renal oxidative stress in Streptozotocin -induced diabetic rats

Aim and Objectives:

In the present study, we have evaluated the antihyperglycemic, hypolipidemic and antioxidant activities of aqueous extract of Phyllanthus amarus (PAAEt) in streptozotocin (STZ)-induced diabetic rats.

Materials and Methods:

PAAEt was administered at 200 mg/kg body weight/day to normal treated (NT-group) and STZ-induced diabetic treated rats (DT-group) by gavage for eight weeks. During the experimental period, blood was collected from fasted rats at 10 days intervals and plasma glucose level was estimated. The plasma lipid profile was estimated at the end of experimental period. After the treatment, period kidney lipid peroxidation (LPO), protein oxidation and reduced glutathione (GSH) were estimated and antioxidant enzymes viz., glutathione reductase (GR), glutathione peroxidase (GPx) and glutathione-S-transferase (GST), catalase (CAT) and superoxide dismutase (SOD) were also assayed.

Results:

The significant decrease in the body weight, hyperglycemia and hyperlipidemia observed in STZ-induced diabetic rats (D-group) were rectified with PAAEt treatment in diabetic treated group (DT-group). D-group rats showed increased renal oxidative stress with increased LPO and protein oxidation. DT-group showed a significant decrease in renal LPO, protein oxidation and a significant increase in GSH content and GR, GPx and GST activities when compared with D-group. The activities of SOD and CAT decreased significantly in D-group, but were normalized in DT-group. Normal rats treated with PAAEt (NT-rats) showed a significant decrease in lipid profile, renal LPO and protein oxidation, with significant increase in renal GSH and activities of antioxidant enzymes compared to normal rats (N-group).

Conclusion:

Our results demonstrated that PAAEt with its antidiabetic, hypolipidemic and antioxidant properties could be a potential herbal medicine in treating diabetes and renal problems.     

Study of the protective effect of ascorbic acid against the toxicity of stannous chloride on oxidative damage, antioxidant enzymes and biochemical parameters in rabbits

Stannous chloride (SnCl2) is a reducing chemical agent used in several man-made products. SnCl2 can generate reactive oxygen species (ROS). Therefore, the present study has been carried out to investigate the antioxidant action of l-ascorbic acid (AA) in minimizing SnCl2 toxicity on lipid peroxidation, antioxidant enzyme, and biochemical parameters in male New Zealand white rabbits. Animals were assigned to one of four treatment groups: 0mg AA and 0mg SnCl2/kg BW (control); 40 mg AA/kg BW; 20mg SnCl2/kg BW; 20mg SnCl2 plus 40 mg AA/kg BW. Rabbits were orally administered the respective doses every other day for 12 weeks. Results obtained showed that SnCl2 significantly (P<0.05) induced thiobarbituric acid-reactive substances (TBARS; the marker of lipid peroxidation) in plasma, while the activities of glutathione S-transferase (GST), superoxide dismutase (SOD) and catalase (CAT), and the level of sulfhydryl groups (SH-group) were decreased (P<0.05) in blood plasma. Aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (AlP), acid phosphatase (AcP) and lactate dehydrogenase (LDH) activities were decreased (P<0.05). Stannous chloride significantly (P<0.05) increased the levels of plasma total lipid (TL), cholesterol, triglyceride (TG), low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL), glucose, urea and total bilirubin. On the other hand, the level of plasma high-density lipoprotein (HDL), total protein (TP), albumin (A) and globulin (G) were significantly (P<0.05) decreased. Ascorbic acid alone significantly decreased the levels of TBARS, lipids and urea, and increased the activities of GST, SOD and CAT, and the levels of SH-group and proteins. While the rest of the tested parameters were not affected. Also, the presence of AA with SnCl2 alleviated its harmful effects on most of the tested parameters. Therefore, the present results revealed that treatment with AA could minimize the toxic effects of stannous chloride.     

Ameliorative effect of vitamins (alpha-tocopherol and ascorbic acid) on PCB (Aroclor 1254) induced oxidative stress in rat epididymal sperm

The aim of this study was to investigate the possible protective role of vitamins on PCB (Aroclor 1254)-induced spermiotoxicity using qualitative, quantitative and biochemical approaches. Adult male albino rats of Wistar strain were randomly divided into four groups, each group consists of six animals. The control group received corn oil, the second group of rats were administered Aroclor 1254 at a dose of 2 mg/kg bw/day intraperitoneally for 30 days. The third group of rats were treated with Aroclor 1254 along with alpha-tocopherol (50 mg/kg of bw/day) for 30 days, while the fourth group of rats were treated with Aroclor 1254 along with ascorbic acid (100 mg/kg bw/day) orally for 30 days. Twenty-four hours after the last treatment, control and experimental animals were killed by decapitation. Sperm was collected from the cauda epididymal region and its count and motility were detected. Sperm was sonicated and used for the estimation of reactive oxygen species (ROS) [hydroxyl radical (HO(*)) and hydrogen peroxide (H(2)O(2))], non-enzymic antioxidants [alpha-tocopherol, ascorbic acid and reduced glutathione (GSH)], activity of enzymic antioxidants [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) glutathione reductase (GR) and glutathione-S-transferase (GST)] and lipid peroxidation (LPO). The result of this experiment shows that PCB significantly decreases the level of alpha-tocopherol, ascorbic acid and GSH and the activities of SOD, CAT, GPx, GR and GST with elevated levels of ROS and LPO. In addition, decreased epididymal sperm motility and count were observed. Simultaneous supplementation with alpha-tocopherol and ascorbic acid restored these parameters to that of normal range. In conclusion, alpha-tocopherol and ascorbic acid exhibited protective effect on sperm by inhibiting PCB-induced ROS generation.     

Antidiabetic effect of Punica granatum flowers: Effect on hyperlipidemia,pancreatic cells lipid peroxidation and antioxidant enzymes in experimental diabetes

The present study investigated the effects of Punica granatum aqueous extract (PgAq) on streptozotocin (STZ) induced diabetic rats by measuring fasting blood glucose, lipid profiles (atherogenic index), lipid peroxidation (LPO) and activities of both non-enzymatic and enzymatic antioxidants. Diabetes was induced by single intraperitoneal injection of STZ (60 mg/kg) to albino Wistar rats. The increase in blood glucose level, total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), very low density lipoprotein (VLDL), LPO level with decrease in high density lipoprotein cholesterol (HDL-C), reduced glutathione (GSH) content and antioxidant enzymes namely, glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST), superoxide dismutase (SOD) and catalase (CAT) were the salient features observed in diabetic rats. On the other hand, oral administration of PgAq at doses of 250 mg/kg and 500 mg/kg for 21 days resulted in a significant reduction in fasting blood glucose, TC, TG, LDL-C, VLDL-C and tissue LPO levels coupled with elevation of HDL-C, GSH content and antioxidant enzymes in comparison with diabetic control group.     

Differential oxidative stress responses to pure Microcystin-LR and Microcystin-containing and non-containing cyanobacterial crude extracts on Caco-2 cells

Cyanobacterial blooms are a worldwide problem due to the production of cyanotoxins such as microcystins (MCs), causing serious water pollution and public health hazard to humans and livestock. Oxidative stress plays a significant role in MCs toxicity. In the present work the differential oxidative stress responses to pure MCs, and Microcystin-containing and non-containing cyanobacterial crude extracts on the human colon carcinoma cell line Caco-2 has been studied for the first time. After exposure, cells were collected and the antioxidant enzymes activities superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-S-transferase (GST) were measured. Moreover, lipid peroxidation (LPO) induction, reactive oxygen species (ROS) and reduced glutathione (GSH) content were also analyzed. The oxidative stress biomarkers that experienced higher alterations were ROS, CAT, SOD and GR activities. The MC containing cyanobacterial extract showed the higher toxic effects, followed by pure MC-LR. The non-MC containing cyanobacterial extract showed limited effects mainly in SOD activity, GSH content, and GP and GR activities only at the highest concentration used. These results suggest that MC-LR is the responsible of the oxidative stress responses observed in Caco-2 cells, but other compounds contained in the cyanobacterial extracts can contribute to the toxic effects.     

Prevention of 1,2-dimethylhydrazine-induced circulatory oxidative stress by bis-1,7-(2-hydroxyphenyl)-hepta-1,6-diene-3,5-dione during colon carcinogenesis

We have performed this study to investigate the modulatory effect of bis-1,7-(2-hydroxyphenyl)-hepta-1,6-diene-3,5-dione, a bisdemethoxy curcumin analog (BDMCA) on circulatory lipid peroxidation (LPO) and antioxidant status during 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis in male Wistar rats. The effects were compared with that of the reference drug, curcumin. Increased tumor incidence as well as enhanced LPO in the circulation of tumor bearing rats was accompanied by a significant decrease in the level of reduced glutathione and activities of glutathione peroxidase (GPx), glutathione S-transferase (GST), superoxide dismutase (SOD) and catalase (CAT). Intragastric administration of BDMCA or curcumin to DMH-treated rats significantly decreased colon tumor incidence and the circulatory LPO, with simultaneous enhancement of GSH content and GPx, GST, SOD and CAT activities. We report that BDMCA exert its chemopreventive effect by decreasing the colon tumor incidence as well as by modulating circulatory oxidative stress in DMH-treated rats through its influence on LPO and antioxidant status. The effects of BDMCA were comparable with that of the reference compound curcumin, a well known anticarcinogen and antioxidant. Thus, it would be suggested that the methoxy group is not responsible for the beneficial effects, however, the terminal phenolic moieties or the central 7-carbon chain may play a role.     

Antioxidant intervention compensates oxidative stress in blood of subjects exposed to emissions from a coal electric-power plant in South Brazil

In the process of energy generation, particulate matter (PM) emissions derived from coal combustion expose humans to serious occupational diseases, which are associated with overgeneration of reactive oxygen species (ROS). The purpose of the present study is to better understand the relations between PM exposure derived from a coal electric-power plant and the oxidative damage in subjects (n=20 each group) directly (working at the burning area) or indirectly (working at the office or living in the vicinity of the electric-power plant=group of residents) exposed to airborne contamination, before and after daily supplementation with vitamins C (500mg) and E (800mg) during six months, which were compared to non-exposed subjects (control group). Several biomarkers of oxidative stress were examined such as levels of thiobarbituric acid reactive substances (TBARS), protein carbonyls (PC), protein thiols (PT) and vitamin E in plasma, levels of reduced glutathione (GSH) in whole blood, and of activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione S-transferase (GST) in red cells. Before supplementation, TBARS and PC levels were significantly increased, levels of GSH and vitamin E were decreased, while the activities of SOD and CAT were increased in workers groups and GST were increased in all groups in compared to controls. After the antioxidant supplementation essentially all these biomarkers were normalized to control levels. The antioxidant intervention was able to confer a protective effect of vitamins C and E against the oxidative insult associated with airborne contamination derived from coal burning of an electric-power plant.     

Habb-e-Asgand,polyherbal Unani formulation,protects liver and antioxidative enzymes against paracetamol induced hepatotoxicity

Context: Habb-e-Asgand, a polyherbal Homeopathy/Unani drug from Hamdard Wakf Laboratory, India, used in arthritis, gout and joint pain, is a mixture of many herbal medicinal plants. Scientific attempts to test and validate its efficacy are meager.

Objective: To evaluate the hepatoprotective and antioxidative potential of Habb-e-Asgand against paracetamol toxicity.

Materials and methods: Swiss albino male mice (n?=?5/group) were treated with Habb-e-Asgand (250?mg/kg, body weight (b.w.) in normal saline orally for 14?days followed by a single dose of paracetamol (400?mg/kg b.w./normal saline) intraperitoneally 24?h before euthanization. We estimated liver function (LFTs) using diagnostic kits, while antioxidant enzymes, cytochrome P450 (CYP) and lipid peroxidation (LPO) were measured using spectrophotometric methods.

Results: Paracetamol alone induced LFTs enzymes significantly (p?p?S-tranferase (GST, ～16%), catalase (CAT, ～84%) and glutathione (GSH, ～30%) contents. Habb-e-Asgand alone and in combination of paracetamol significantly (p?Discussion: Paracetamol metabolites may be mediating production of reactive oxidant species (ROS) and liver injury, which are attenuated by Habb-e-Asgand antioxidant constituents.

Conclusion: Habb-e-Asgand may be used as a prophylaxis for ROS related liver injury.     

Protective Role of Curcumin against N-Nitrosodiethylamine (NDEA)-Induced Toxicity in Rats

The present investigation was aimed at studying the possible role of curcumin against N-nitrosodiethylamine (NDEA)-induced toxicity in albino rats. Administration of NDEA to rats at a concentration of 0.1 mg/ml in drinking water ad libitum for 21 days produced toxicity in them, which was evident from histopathological changes in the rat livers, and increased levels of blood serum enzyme markers, i.e. aspartate transaminase, alanine transaminase, alkaline phosphatase, and lactate dehydrogenase. In addition, the levels of oxidative stress markers like lipid peroxidation (LPO), protein carbonyl (PCC), and glutathione-S-transferase (GST) activity were elevated and the total glutathione (GSH) content was reduced in the livers. The administration of curcumin to rats at concentrations of 10, 20, and 40 mg/ml in drinking water along with 0.1 mg/ml of NDEA for 21 days effectively suppressed NDEA-induced toxicity and also resulted in a dose-dependent reduction in the levels of blood serum enzyme markers (AST, ALT, ALP, and LDH). Moreover, LPO, PCC, and GST activity were reduced and the GSH level was increased upon the administration of curcumin along with NDEA. The results obtained for the comet assay in rat hepatocytes and blood lymphocytes showed a significant dose-dependent decrease in the mean tail length. The micronucleus assay performed on rat hepatocytes also showed a dose-dependent reduction in the frequency of micronucleated cells along with curcumin administration. These results suggest that curcumin has a protective role against NDEA-induced toxicity in albino rats.