Polycyclic aromatic hydrocarbon coated onto Fe(2)O(3) particles: assessment of cellular membrane damage and antioxidant system disruption in human epithelial lung cells (L132) in culture

The aim of this study was to investigate the oxidative effects of Fe(2)O(3), benzo(a)pyrene (B(a)P) and pyrene, alone or in association (B(a)P or pyrene coated onto Fe(2)O(3) particles), in normal human embryonic lung epithelial cells (L132) in culture. We evaluated: (i) membrane integrity, through fatty acid release (stearic acid, oleic acid, linoleic and linolenic acids, homolinolenic acid, arachidonic acid) and malondialdehyde (MDA) production; and (ii) antioxidant status, through enzymatic and non-enzymatic antioxidant defenses (superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione status, beta-carotene). Fe(2)O(3) did not induce any change in L132 cells. In pyrene-treated cells, SOD induction (P<0. 05), glutathione oxidation (P<0.05) and beta-carotene consumption (P<0.001) may counteract free radicals (FR)-induced damage. However, in B(a)P-incubated cells, SOD inactivation (P<0.05), GR increases (P<0.05), glutathione oxidation (P<0.05) and beta-carotene decreases (P<0.001) showed high disruption of antioxidants, thereby allowing FR-induced damage (i.e. arachidonic acid release, P<0.01; MDA production, P<0.01). Our main finding was that both associations caused higher FR-induced damage (i.e. MDA production, P<0.001; SOD inactivation, P<0.01) than either chemical alone. Several mechanisms could account for this result: enhanced uptake of Fe(2)O(3) particles and/or greater availability of polycyclic aromatic hydrocarbons (PAHs). We hypothesized also that Fe(2)O(3) and polycyclic aromatic hydrocarbons are more deleterious by virtue of their associations being able to produce higher oxidative effects than either chemical alone.     

Diallyl trisulfide (DATS) effectively attenuated oxidative stress-mediated liver injury and hepatic mitochondrial dysfunction in acute ethanol-exposed mice

The protective effects of diallyl trisulfide (DATS) on acute ethanol-induced liver injury were investigated. Mice were pretreated with DATS (30mg/kgbw) for 7d before being exposed to ethanol (4.8g/kgbw). The biochemical indices (aspartate amino transferase, AST; alanine amino transferase, ALT; triglyceride, TG) were examined to evaluate the protective effects. Mitochondria were isolated for the mitochondrial permeability transition (MPT), membrane potential (DeltaPsi(m)) and adenosine nucleotide pool assay. The lipid peroxidation (malondialdehyde, MDA), non-enzymatic antioxidant (glutathione, GSH) and enzymatic antioxidants (superoxide dismutase, SOD; catalase, CAT; glutathione reductase, GR; glutathione peroxidase, GSH-Px) were measured both in the liver homogenate and isolated mitochondria. Acute ethanol exposure resulted in the significant increase of the ALT, AST and TG levels and hepatic mitochondria dysfunction shown as MPT, and the decreases of DeltaPsi(m), ATP and energy charge (EC). However, DATS pretreatment dramatically attenuated these adverse effects. Beside this, DATS was found to significantly inhibit the increase of the hepatic and mitochondrial MDA levels, which were decreased by 33.3% (P<0.01) and 39.0% (P<0.01), respectively. In addition, DATS pretreatment markedly suppressed the ethanol-induced decrease of the hepatic GSH level and increased the mitochondrial GSH level. Moreover, the activities of the hepatic antioxidant enzymes (SOD, CAT, and GR) and the mitochondrial antioxidant enzymes (SOD, GR, and GSH-Px) were significantly boosted. Thus, we concluded that DATS dramatically attenuated acute ethanol-induced liver injury and mitochondrial dysfunction. The increase of the hepatic and mitochondrial GSH levels and the elevation of the antioxidant enzymes activities should account for the preventive effects.     

Dose dependent protection by lipoic acid against cisplatin-induced ototoxicity in rats: antioxidant defense system.

This study investigated the alterations that occur in auditory brainstem-evoked responses (ABRs) concurrent with changes in cochlear concentrations of glutathione (GSH), lipid peroxidation, and antioxidant enzyme activity in cisplatin-induced ototoxicity and in dose-dependent otoprotection by an antioxidant lipoate. Male Wistar rats were divided into different groups and were treated as follows, with: (1) vehicle (saline) control; (2) cisplatin (16 mg/kg, i.p.); (3) lipoate (100 mg/kg, i.p.) plus saline; (4) cisplatin plus lipoate (25 mg/kg); (5) cisplatin plus lipoate (50 mg/kg), and (6) cisplatin plus lipoate (100 mg/kg). Post-treatment ABRs were evaluated after three days, the rats were sacrificed, and cochleae were harvested and analyzed. The cisplatin-injected rats showed ABR threshold elevations above the pre-treatment thresholds. Rats treated with lipoate plus cisplatin did not show significant elevation of hearing thresholds. Cisplatin administration resulted in a depletion of cochlear GSH concentration (69% of control), whereas, cisplatin-plus-lipoate treatment increased GSH concentration close to control value. Cisplatin-treated rats showed a decrease in cochlear superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and glutathione reductase (GR) activities (57, 78, 59, and 58% of control, respectively), and an increase in malondialdehyde (MDA) concentration (196% of control). Cochlear SOD, CAT, GSH-Px, and GR activities and MDA concentrations were restored in the rats injected with cisplatin plus graded doses of lipoate than those with cisplatin alone. It is concluded that cisplatin-induced ototoxicity is related to impairment of the cochlear antioxidant defense system, and the dose-dependent otoprotection conferred by an antioxidant lipoate against cisplatin ototoxicity is associated with sparing of the cochlear antioxidant defense system.     

Changes in antioxidant defense systems induced by thiram in V79 Chinese hamster fibroblasts.

The role of antioxidant defence systems in protection against oxidative damage of lipids and proteins induced by fungicide thiram during in vitro exposure was investigated in cultured Chinese hamster V79 cells with normal, depleted, and elevated glutathione (GSH) levels. We analyzed the catalytic activities of superoxide dismutases (SOD1 and SOD2), Se-dependent and Se-independent glutathione peroxidases (GSH-Px), glutathione reductase (GR), and catalase (CAT), as well as total glutathione/glutathione disulfide ratio (GSH(total)/GSSG). Thiram treatment resulted in an increase in activities of SOD1, Se-dependent GSH-Px, and GR at the highest tested dose (150 microM). On the contrary, inhibition of CAT and Se-independent GSH-Px activities, and no significant changes in the level of SOD2 activity was observed at any tested doses (100-150 microM). GSH(total)/GSSG ratio in the 100 microM thiram treated cells was not significantly changed comparing to the control, despite significant decrease of GSH total (50%). In 150 microM thiram treated cells the ratio falls to 43% of control value. Pretreatment with l-buthionine sulfoximine (L-BSO), an inhibitor of GSH synthesis, significantly enhanced decrease in CAT and Se-independent GSH-Px activities, as well as GSH(total)/GSSG ratio, and reduced Se-dependent GSH-Px activity, following exposure to thiram. Simultaneously, L-BSO pretreatment enhanced increase in SOD1 activity, and had no effect on SOD2, following thiram exposure. Pretreatment with N-acetyl cysteine (NAC), a GSH precursor, prevented enzymatic changes in CAT, Se-dependent GSH-Px, GR, SOD1 activities, and significantly decreased SOD2 activity following exposure to thiram. GSH(total)/GSSG ratio was restored to the control value. This study suggests that following the changes in antioxidant defense systems thiram can act through the production of free radicals.     

Effects of trimetazidine on oxidant/antioxidant status in trinitrobenzenesulfonic acid-induced chronic colitis

Trimetazidine (TMZ), an anti-ischemic agent with proposed antioxidant properties, was used in a chronic colitis model in order to evaluate its effectiveness as a therapeutic agent in chronic colitis. Treatment of male Swiss Albino rats with ethanol (50%) and trinitrobenzenesulfonic acid (TNBS) (30 mg/kg) produced colitis as evidenced by histopathologic damage and inflammatory alterations, lipid peroxidation [increased malondialdehyde (MDA) levels], and enhanced neutrophil infiltration [increased myeloperoxidase (MPO) activity] without marked change in glutathione status. Administration of TMZ (5 mg/kg) to TNBS-treated rats failed to affect the TNBS-induced changes in histopathology and MPO activities. Unexpectedly, intrarectal (i.r.) administration of TMZ significantly elevated colonic MDA levels to a greater extent than TNBS alone. Intraperitoneal (i.p.) TMZ treatment seemed to increase total glutathione (tGSH), GSH, and GSH/GSSG values. In conclusion, our results demonstrated that (a) i.r. administration of ethanol and TNBS is an effective way of inducing a chronic colitis model, (b) inflammation and lipid peroxidation augment tissue damage in the chronic colitis model, (c) i.p. TMZ treatment significantly inhibits MDA production in the chronic colitis model, (d) TMZ treatment is more effective via the i.p. compared to i.r. route, and (e) TMZ seems to show its antioxidant effect via preserving the tissue's GSH/GSSG ratios.     

Pro/antioxidant status in young healthy women using oral contraceptives

The aim of the study was to analyze the effects of oral contraceptives (OCs) on pro/antioxidant status in the blood of healthy women aged 20–25 years.Individuals were divided into OCs users and OCs nonusers. Markers of oxidative stress in the blood such as Cu, Cu/Zn ratio, malondialdehyde (MDA), glutathione oxidized (GSSG), and gamma-glutamyl transpeptidase (GGT) were determined. Antioxidants such as glutathione reduced (GSH), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione S-transferase (GST), and superoxide dismutase (SOD) were estimated.Higher Cu concentrations, Cu/Zn ratio and GGT activity in women taking OCs were noted. A significant increase in MDA concentrations in oral OCs users was observed. Heightened activity of CAT in plasma was observed in OCs users, whereas SOD activity remained unchanged in plasma and erythrocyte lysate. A decline of GSH and GSSG in whole blood and glutathiono-dependent enzymes (GPx in plasma, GR in plasma and GST in lysate) was shown.Use of OCs leads to a pro/antioxidant imbalance. The results in the present study confirmed that GGT is an early marker of oxidative stress. Catalase is the main antioxidant, involved in the removal of free radicals in OCs users.     

4-Methylthiobenzoic Acid Protection against Cisplatin Nephrotoxicity: Antioxidant System

This study investigates the changes in renal antioxidant systemafter cisplatin administration and the nephroprotection with4-methylthiobenzoic acid (MTBA). Male Wistar rats were injectedwith (1) vehicle control, (2) cisplatin, (3) MTBA, and (4) cisplatinplus MTBA. Rats were euthenized 3 days post-treatment and kidneywas isolated and analyzed for platinum concentration, malondialdehyde (MDA), glutathione (GSH and GSSG), superoxide dismutase(SOD), catalase (CAT), and glutathione peroxidase (GSH-Px).Plasma creatinine increased 508% following cisplatin administrationalone, which decreased to 189% with MTBA. Cisplatin-treatedrats showed a depletion of renal GSH levels (53%), while cisplatinplus MTBA-injected rats had GSH values close to those of thecontrols. SOD, CAT, and GSH-Px activities decreased 36, 29,and 38%, respectively, and MDA levels increased 212% followingcisplatin administration, which were restored to control levelsafter MTBA treatment. The renal platinum level depleted significantlywith MTBA treatment. The data suggest that cisplatin nephrotoxicityis mediated by depletion in GSH concentration and by impairedactivities of SOD, CAT, and GSH-Px, increased lipid peroxidation,and plasma creatinine levels. The protection offered by MTBAagainst cisplatin nephrotoxicity is related to the reductionin plasma creatinine levels, prevention of GSH depletion andlipid peroxidation, and restoring antioxidant enzyme activityin the kidneys of rats.     

Reversal of cadmium induced oxidative stress by chelating agent, antioxidant or their combination in rat

The influence of an antioxidant agent such as N-acetyl cysteine (NAC) or mannitol on the cadmium chelating ability of monoisoamyl 2,3-dimercaptosuccinate (MiADMS) was investigated in cadmium pre-exposed rats. This ester of 2,3-dimercaptosuccinic acid (DMSA), an accepted drug for lead poisoning, being lipophilic in nature was expected to be an efficient cadmium chelator. The treatment of cadmium intoxicated animals with MiADMS reversed cadmium induced increase in blood catalase, superoxide dismutase (SOD) and malondialdehyde (MDA), liver MDA and brain SOD and MDA levels but not the decrease in blood, liver brain reduced glutathione (GSH) and increase in oxidized glutathione (GSSG) levels, consistent with the lowering of tissue cadmium burden. The administration of NAC or mannitol reversed the cadmium induced alterations in blood and liver GSH, GSSG, blood catalase, SOD, MDA, liver SOD, MDA and brain MDA levels without lowering blood and tissue cadmium contents. However, treatments with the combination of MiADMS and NAC or MiADMS and mannitol reversed these alterations as well as reduced blood and tissue cadmium concentrations. The combined treatment with MiADMS and mannitol was better than that with MiADMS and NAC, and was significantly more effective in normalizing blood, liver GSH, GSSG, brain GSSG, and their GSH/GSSG ratios than that by either of them alone. The combined treatments also improved liver and brain endogenous zinc levels, which were decreased due to cadmium toxicity. The results suggest that the administration of an antioxidant during chelation of cadmium may provide beneficial effects by reducing oxidative stress without its cadmium removing ability.     

Protective role of caffeic acid phenethyl ester (cape) on gentamicin-induced acute renal toxicity in rats

The toxicity of gentamicin (GEN) in the kidney seems to relate to the generation of reactive oxygen species (ROS). Caffeic acid phenethyl ester (CAPE) has been demonstrated to have antioxidant, free radical scavenger and anti-inflammatory effects. It has been proposed that antioxidant maintain the concentration of reduced glutathione (GSH) may restore the cellular defense mechanisms and block lipid peroxidation thus protect against the toxicity of wide variety of nephrotoxic chemicals. We investigated the effects of CAPE on GEN-induced changes in renal malondialdehyde (MDA), a lipid peroxidation product, nitric oxide (NO) generation, superoxide dismutase (SOD), catalase (CAT) activities, GSH content, blood urea nitrogen (BUN) and serum creatinine (Cr) levels. Morphological changes in the kidney were also examined. A total of 32 rats were equally divided into four groups which were: (1) control, (2) injected with intraperitoneally (i.p.) GEN, (3) injected with i.p. GEN+CAPE and (4) injected with i.p. CAPE. GEN administration to control rats increased renal MDA and NO generation but decreased SOD and CAT activities, and GSH content. CAPE administration with GEN injections caused significantly decreased MDA, NO generation and increased SOD, CAT activities and GSH content when compared with GEN alone. Serum level of BUN and Cr significantly increased as a result of nephrotoxicity. CAPE also, significantly decreased serum BUN and Cr levels. Morphological changes in the kidney due to GEN, including tubular necrosis, were evaluated qualitatively. In addition, CAPE reduced the degree of kidney tissue damage induced by GEN. Both biochemical findings and histopathological evidence showed that administration of CAPE reduced the GEN-induced kidney damage. Our results indicated that CAPE acts in the kidney as a potent scavenger of free radicals to prevent the toxic effects of GEN both at the biochemical and histological level. Thus, CAPE could be effectively combined with GEN treatment.     

Time-dependent changes of lipid peroxidation and antioxidative status in nerve tissues of hens treated with tri-ortho-cresyl phosphate (TOCP)

Tri-ortho-cresyl phosphate (TOCP) could induce a delayed neurodegenerative condition known as organophosphorus easter-induced delayed neurotoxicity (OPIDN) in human beings and sensitive animals. However, the mechanisms of OPIDN remain unknown. This study investigated the time-dependent changes of the lipid peroxidation (malondialdehyde, MDA) and antioxidative status (glutathione, GSH; glutathione peroxidase, GSH-Px; glutathione reductase, GR; superoxide dismutase, SOD and anti-reactive oxygen species, anti-ROS) in nerve tissues for elucidating the mechanism of OPIDN induced by TOCP. Adult hens were treated with TOCP by gavage at a single dosage of 750 mg/kg. TOCP was dissolved in corn oil and administered at 0.65 ml/kg. The control hens received an equivalent volume of corn oil by gavage. Hens were sacrificed after 0, 5, 10, 15 and 21 days of treatment and the cerebrum, spinal cord, sciatic nerve were dissected, homogenized and used for the determination of lipid peroxidation and antioxidative status. The results showed that treatment with TOCP increased lipid peroxidation and reduced the antioxidative status in cerebrum, spinal cord and sciatic nerve. The levels of MDA increased by 33% (P<0.01) in cerebrum on 5th day after TOCP treatment and at clinical sign score of 1-2, and increased respectively by 32% and 15% (P<0.01) in spinal cord and sciatic nerve on 10th day after TOCP treatment and at clinical sign score of 3-4. Further changes of MDA were also observed after 15 and 21 days post-dosing and at clinical sign score of 5-6 and 7-8. There is a decrease in the activities of SOD, GSH-Px, GR, anti-ROS, and GSH content in cerebrum, spinal cord and sciatic nerve of hens after 5, 10, 15 and 21 days post-dosing and at clinical sign score of 1-2, 3-4, 5-6 and 7-8. Thus, OPIDN induced by TOCP was associated with elevation of lipid peroxidation and reduction of antioxidative status, and the time-dependent changes of these indexes in hens nerve tissues occurred. Sciatic nerve was the main target tissue and MDA was most sensitive among all indexes. The time-dependent and tissue specific changes of lipid peroxidation and antioxidative status in cerebrum, spinal cord and sciatic nerve suggest that ROS and concomitant lipid peroxidation, at least in part, are involved in the toxic effects of TOCP on nerve tissues and that oxidative stress may play a role in the occurrence and development of OPIDN induced by TOCP.     

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.     

Pulmonary induction of proinflammatory mediators following the rat exposure to benzo(a)pyrene-coated onto Fe2O3 particles

Epidemiological evidence firmly implicated an interactive effect between Fe2O3 and benzo(a)pyrene (B(a)P) in causing lung cancer. However, despite intensive investigation, the mechanism involved is not precisely established. Since the accumulation of reactive oxygen intermediates (ROI)-mediated damage and/or immune-induced injury might be a possible cause of lung cancer, we studied the oxidative and the inflammatory effects of Fe2O3 (3 mg), B(a)P (3 mg) or B(a)P (3 mg)-coated onto Fe2O3 (3 mg) particles on this relevant organ target in Sprague-Dawley rats. We investigated lipid peroxidation (malondialdehyde; MDA) and secretion of some inflammatory mediators (tumor necrosis factor-alpha, TNF-alpha; interleukin-1 beta, IL-1beta; nitric oxide, NO) in lungs. In addition, mRNA expressions of TNF-alpha, IL-1beta and inducible nitric oxide synthase (iNOS) were evaluated. Our results show that exposure to Fe2O3 and B(a)P, alone or in association, induced 2-fold increases in MDA production suggesting thereby oxidative stress conditions (P<0.01). Exposure to Fe2O3, B(a)P or B(a)P-coated onto Fe2O3 particles significantly increased both mRNA expression and/or synthesis of inflammatory mediators. The main findings of this work were that the association of Fe2O3 and B(a)P induces more pronounced induction of inflammatory mediators (IL-1beta secretion, P<0.01; IL-1beta mRNA expression, P<0.01; iNOS mRNA expression, P<0.05) than B(a)P by itself. Hence, our results may explain why concurrent exposure to Fe2O3 and B(a)P is more deleterious in lungs than exposure to B(a)P alone.     

Comparative study of the antioxidant effect of ardisin and epigallocatechin gallate in rat hepatocytes exposed to benomyl and 1-nitropyrene.

The objective of this study was to compare the antioxidant effect of ardisin and epigallocatechin 3-O-gallate (EGCG) in hepatocytes exposed to either benomyl or 1-nitropyrene (1-NP). Rat hepatocytes were incubated in a serum-free medium with non-cytotoxic concentrations of either ardisin (0.27 microg/ml) or EGCG (3 microg/ml), and with either benomyl (35 microg/ml) or 1-NP (0.25 microg/ml). The level of malondialdehyde (MDA) as a marker of lipid peroxidation was determined, as well as the content of glutathione (GSH) and the activities of glutathione peroxidase (GPx) and glutathione reductase (GR). In comparison to the control, the concentration of GSH improved 282% (P<0.05) and 260% (P<0.05) after the cells were pre-incubated with ardisin or EGCG and then exposed to benomyl, respectively. The activity of GPx decreased 55% with ardisin (P<0.05) and 51% with EGCG (P<0.05), and MDA decreased 7% and 23% (P<0.05) with the same treatments. The concentration of GSH also improved when the cells were incubated with either EGCG (49%, P<0.05) or ardisin (83%, P<0.05) simultaneously with 1-NP, relative to 1-NP alone. Moreover, ardisin decreased MDA formation by 65% (p<0.05), and enhanced the activity of GR by 137% (P<0.05). These results suggest that ardisin is a better suppressor of lipid peroxidation induced by benomyl and 1-NP than EGCG. It is concluded that ardisin and EGCG are potent antioxidants that can afford protection against free radical mediated diseases.     

Modifications on Antioxidant Capacity and Lipid Peroxidation in Mice under Fraxetin Treatment

Fraxetin belongs to an extensive group of natural phenolic antioxidants. We have investigated the modifications in endogenous antioxidant capacity; superoxide dismutase (SOD), catalase (CAT), total and selenium-dependent glutathione peroxidases (GPx) and glutathione reductase (GR) and stress index; glutathione disulphide (GSSG)/reduced glutathione (GSH) ratio and thiobarbituric acid-reactive substances (TBARs) in liver and brain supernatants of C57BL/6J male 12-month-old mice under fraxetin treatment for 30 days. Liver SOD and GPx (total and Se-dependent) activities were not significantly affected by fraxetin, whereas they were increased in the brain compared with control animals. GR activity increased significantly only in the liver of treated mice. Fraxetin treatment-related decreases were shown for GSSG/GSH ratio and rate of accumulation of TBARs (not significant in TBARs) in both tissues. We concluded that the net effect of fraxetin treatment on endogenous antioxidant capacity suggests that this compound might provide an important resistance to, or protection against, free-radical-mediated events which contribute to degenerative diseases of ageing.     

Acute administration of 3,4-methylenedioxymethamphetamine (MDMA) induces oxidative stress, lipoperoxidation and TNFα-mediated apoptosis in rat liver

Liver toxicity is one of the consequences of ecstasy (3,4-methylenedioxymethamphetamine MDMA) abuse and hepatocellular damage is reported after MDMA consumption. Various factors probably play a role in ecstasy-induced hepatotoxicity, namely its metabolism, the increased efflux of neurotransmitters, the oxidation of biogenic amines, and hyperthermia. MDMA undergoes extensive hepatic metabolism that involves the production of reactive metabolites which form adducts with intracellular nucleophilic sites. MDMA-induced-TNF-α can promote multiple mechanisms to initiate apoptosis in hepatocytes, activation of pro-apoptotic (BID, SMAC/DIABLO) and inhibition of anti-apoptotic (NF-κB, Bcl-2) proteins. The aim of the present study was to obtain evidence for the oxidative stress mechanism and apoptosis involved in ecstasy-induced hepatotoxicity in rat liver after a single 20 mg/kg, i.p. MDMA administration. Reduced and oxidized glutathione (GSH and GSSG), ascorbic acid (AA), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR) and malondialdehyde (MDA), an indicator of lipid peroxidation, were determined in rat liver after 3 and 6 h after MDMA treatment. The effect of a single MDMA treatment included decrease of GR and GPx activities (29% and 25%, respectively) and GSH/GSSG ratio (32%) with an increase of MDA (119%) after 3 h from ecstasy administration compared to control rats. Liver cytosolic level of AA was increased (32%) after 6 h MDMA treatment. Our results demonstrate a strong positive reaction for TNFα (p < 0.001) in hepatocytes and a diffuse apoptotic process in the liver specimens (p < 0.001). There was correlation between immunohistochemical results and Western blotting which were quantitatively measured by densitometry, confirming the strong positivity for TNF-α (p < 0.001) and NF-κB (p < 0.001); weak and intense positivity reactions was confirmed for Bcl-2, SMAC/DIABLO (p < 0.001) and BID reactions (p < 0.001).The results obtained in the present study suggest that MDMA induces loss of GSH homeostasis, decreases antioxidant enzyme activities, and lipoperoxidation that causes an oxidative stress that accompaines the MDMA-induced apoptosis in liver cells.     

Carnosic acid attenuates renal injury in an experimental model of rat cisplatin-induced nephrotoxicity

Nephrotoxicity is one of the serious dose limiting side effects of cisplatin when used in the treatment of various malignant conditions. Accumulating evidence suggests that oxidative stress caused by free radicals and apoptosis of renal cells contributes to the pathogenesis of cisplatin-induced nephrotoxicity. Present study was aimed to explore the effect of carnosic acid, a potent antioxidant, against cisplatin induced oxidative stress and nephrotoxicity in rats. A single dose of cisplatin (7.5 mg/kg) caused marked renal damage, characterized by a significant (P < 0.05) increase in serum creatinine, blood urea nitrogen (BUN) and relative weight of kidney with higher kidney MDA (malondialdehyde), tROS (total reactive oxygen species), caspase 3, GSH (reduced glutathione) levels and lowered tissue nitrite, SOD (superoxide dismutase), CAT (catalase), GSH-Px (glutathione peroxidase), GR (glutathione reductase) and GST (glutathione S-transferase) levels compared to normal control. Carnosic acid treatment significantly (P < 0.05) attenuated the increase in lipid peroxidation, caspase-3 and ROS generation and enhanced the levels of reduced glutathione, tissue nitrite level and activities of SOD, CAT, GSH-Px, GR and GST compared to cisplatin control. The present study demonstrates that carnosic acid has a protective effect on cisplatin induced experimental nephrotoxicity and is attributed to its potent antioxidant and antiapoptotic properties.     

EFFECTS OF TRIMETAZIDINE ON OXIDANT/ANTIOXIDANT STATUS IN TRINITROBENZENESULFONIC ACID-INDUCED CHRONIC COLITIS

Trimetazidine (TMZ), an anti-ischemic agent with proposed antioxidant properties, was used in a chronic colitis model in order to evaluate its effectiveness as a therapeutic agent in chronic colitis. Treatment of male Swiss Albino rats with ethanol (50%) and trinitrobenzenesulfonic acid (TNBS) (30 mg/kg) produced colitis as evidenced by histopathologic damage and inflammatory alterations, lipid peroxidation [increased malondialdehyde (MDA) levels], and enhanced neutrophil infiltration [increased myeloperoxidase (MPO) activity] without marked change in glutathione status. Administration of TMZ (5 mg/kg) to TNBS-treated rats failed to affect the TNBS-induced changes in histopathology and MPO activities. Unexpectedly, intrarectal (ir) administration of TMZ significantly elevated colonic MDA levels to a greater extent than TNBS alone. Intraperitoneal (ip) TMZ treatment seemed to increase total glutathione (tGSH), GSH, and GSH/GSSG values. In conclusion, our results demonstrated that (a) ir administration of ethanol and TNBS is an effective way of inducing a chronic colitis model, (b) inflammation and lipid peroxidation augment tissue damage in the chronic colitis model, (c) ip TMZ treatment significantly inhibits MDA production in the chronic colitis model, (d) TMZ treatment is more effective via the ip compared to ir route, and (e) TMZ seems to show its antioxidant effect via preserving the tissue's GSH/GSSG ratios.     

Dose- and time-dependent effects of sulfur mustard on antioxidant system in liver and brain of rat

This study investigates the dose- and time-dependent effects of sulfur mustard (SM) on antioxidant system and lipid peroxidation in liver and brain of rats. For this purpose, male Wistar rats were randomly divided into eight groups and treated as follows: group 1 as control and groups 2-8 as experimental groups that received SM (1-80 mg/kg) through intraperitoneal injection. Rats were killed after 2, 7 and 14 days of exposure. SM dose-dependently decreased body weight. Superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST) activities in liver were significantly increased at SM doses lower than 10 mg/kg after 2 and 7 days of exposure. However, the recovery of these parameters was observed after 14 days. At these concentrations, no significant change in glutathione (GSH) and malondialdehyde (MDA) levels were observed. At doses higher than 10 mg/kg, SM significantly decreased SOD, CAT, glutathione peroxidase (GPX), and GST activities in liver and brain and decreased glutathione reductase (GR) activity in liver, which was associated with a depletion of GSH and increased MDA level. Present data indicate that the effect of SM is dose- and time-dependent and at higher doses (>10 mg/kg) induces an oxidative stress response by depleting the antioxidant defense systems and increasing lipid peroxidation in liver and brain of rats.     

Brahma Rasayana enhances in vivo antioxidant status in cold-stressed chickens (Gallus gallus domesticus)

Objective:

To evaluate the antioxidant status of chicken during cold stress and to investigate if there are any beneficial effects of Brahma Rasayana supplementation in cold stressed chicken.

Materials and Methods:

Activities of enzymatic and levels of non-enzymatic antioxidants in blood / serum and liver tissue were evaluated in chicken exposed to cold (4 ± 10C and relative humidity of 40 ± 5%, for six consecutive hours daily, for 5 or 10 days). The antioxidant properties of Brahma Rasayana (BR) supplementation (2 g/kg daily, orally) during cold stress was also studied.

Results:

There was a significant (P < 0.05) decrease in antioxidant enzyme in the blood, such as, superoxide dismutase (SOD), glutathione peroxidase (GPX), glutathione reductase (GR), and serum reduced glutathione (GSH) in cold stressed chicken. Serum and liver lipid peroxidation levels were significantly (P < 0.05) higher in cold stressed untreated chickens when compared to the treated and unstressed groups. There was also a significant (P < 0.05) increase in the antioxidant enzymes in the blood, such as, catalase (CAT) and SOD, in the liver CAT and SOD, and in GPX and GR in BR-treated cold stressed chicken, when compared to the untreated controls.

Conclusions:

Results of the present study conclude that in chicken, BR supplementation during cold stress brings about enhanced actions of the enzymatic and non-enzymatic antioxidants, which nullify the undesired side effects of free radicals generated during cold stress.     

Quercetin, a flavonoid antioxidant, prevents and protects against ethanol-induced oxidative stress in mouse liver

This study evaluates whether quercetin (25, 50 and 75 mg/kg body weight) treatment has a protective effect on the pro-oxidant-antioxidant state following chronic ethanol treatment in mice. Pretreatment (quercetin 25, 50 and 75 mg/kg body weight for 15 d+co-treatment of ethanol 18%+quercetin for 15 d and ethanol 18% for the 15 d) increased the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione (GSH) in comparison to the ethanol group. No significant differences from the ethanol group were observed in the group after post-treatment (ethanol 18% for 30 d+quercetin 25, 50 and 75 mg/kg body weight for 15 d) with quercetin. A significant increase in lipid peroxidation (malondialdehyde, MDA) products was observed in liver tissue after administration of ethanol, which was attenuated by pre- and post-treatment with a high dose of quercetin. GSH levels increased and oxidized glutathione (GSSG) levels decreased in groups of ethanol-exposed mice that received quercetin for 15 d prior to ethanol exposure. In conclusion, pre-treatment of quercetin may protect against ethanol-induced oxidative stress by directly quenching lipid peroxides and indirectly by enhancing the production of the endogenous antioxidant GSH. There was no protective effect on post-treatment with quercetin.