Garlic ameliorates gentamicin nephrotoxicity: relation to antioxidant enzymes

Prevention of hepatic and renal toxicity with bradykinin potentiating factor (BPF) isolated from Egyptian scorpion venom (Buthus occitanus) in gentamicin treated rats

The present investigation report the effect of a bradykinin-potentiating factor (BPF) on gentamicin-induced oxidative stress in rat liver and kidney. BPF is a peptide fraction isolated from the venom of the Egyptian scorpion (Buthus occitanus) has been demonstrated to have antioxidant, free radical scavenger and anti-inflammatory effects. Thirty male Rattus norvegicus (130-150 g) were included and divided into three equal groups as follows: Group I (control), group II was (ip) injected with gentamicin alone (80 mg/kg/day) for 15 days, group III was given (ip) injection of BPF (1mg/kg/day) one hour prior to gentamicin treatment for 15 days with the same dose of gentamicin as group II. Both organs were subjected to histopathological analysis with the light microscope. The activities of alanine aminotransferase (ALT), asparate aminotransferase (AST) and alkaline phosphatase (ALP) in serum were measured as indicators of the liver function. As parameters of the kidney function, creatinine, uric acid and urea concentrations were determined. Also, malondialdehyde (MDA), reduced glutathione (GSH), super oxide dismutase (SOD) and catalase (CAT) were determined in both tissues. Gentamicin caused a significant decrease or inhibition in the activities of GSH, SOD, and CAT, with significant increase in the level of MDA, ALT, AST, ALP, as well as creatinine, uric acid and urea concentrations in versus to control groups in both liver and kidney. Co-administration of gentamicin and BPF significantly increased the activity of GSH, SOD, and CAT, with significant decrease in the level of MDA and maintained serum (ALT); (AST); (ALP), creatinine, uric acid and urea concentrations as the same level as control group. Moreover, administration of gentamicin resulted in damage to liver and kidney structures. Administration of BPF before gentamicin exposure prevented severe alterations of biochemical parameters and disruptions of liver and kidney structures. In conclusion, this study obviously demonstrated that pretreatment with BPF significantly attenuated the physiological and histopathological alterations induced by gentamicin. Also, the present study identifies new areas of research for development of better therapeutic agents for liver, kidney, and other organs dysfunctions and diseases.

Nephroprotective activity of Solanum xanthocarpum fruit extract against gentamicin-induced nephrotoxicity and renal dysfunction in experimental rodents

OBJECTIVE

To evaluate nephroprotective potential of Solanum xanthocarpum (S. xanthocarpum) fruit extract(SXE) against gentamicin (GM) induced nephrotoxicity and renal dysfunction.

METHODS

Twenty-four Wistar rats were divided into four groups (n=6). Control rats that received normal saline (i.p.) and 0.5% carboxymethyl cellulose (p.o.) per day for 8 d. Nephrotoxicity was induced in rats by intraperitoneal administration of GM (100 mg/kg/d for 8 d) and were treated with SXE (200 and 400 mg/kg/d (p.o.) for 8 d). Plasma and urine urea and creatinine, kidney weight, urine output, blood urea nitrogen, renal enzymatic and non-enzymatic antioxidants and lipid peroxidation was evaluated along with histopathological investigation in various experimental groups of rats.

RESULTS

It was observed that the GM treatment induced significant elevation (P<0.001) in plasma and urine urea, creatinine, kidney weight, blood urea nitrogen, renal lipid peroxidation along with significant decrement (P<0.001) in urine output, renal enzymatic and non-enzymatic antioxidants. SXE 200 and 400 mg/kg treatment to GM treated rats recorded significant decrement (up to P<0.001) in plasma and urine urea and creatinine, renal lipid peroxidation along with significant increment (up to P<0.001) in renal enzymatic and non-enzymatic antioxidants. Histological observations of kidney tissues too correlated with the biochemical observations.

CONCLUSIONS

These finding powerfully supports that S. xanthocarpum fruit extract acts in the kidney as a potent scavenger of free radicals to prevent the toxic effects of GM both in the biochemical and histopathological parameters and thus validates its ethnomedicinal use.

Preventive effect of danshensu on selenite-induced cataractogenesis in cultured rat lens

BACKGROUND

To investigate the preventive effect of danshensu on the selenite-induced opacification of cultured rat lenses.

METHODS

Isolated lens were divided into three groups with eight lenses in each group. Group I: lenses were incubated with M199 medium alone; Group II: incubated in M199 containing 200 µmol/L sodium selenite; Group III: incubated in M199 containing 200 µmol/L sodium selenite and 500 µmol/L danshensu. Selenite was administered on the third day, and danshensu treatment was from the second to the fifth day. Cataracts development was observed using an inverted microscope, and the lenses were analysed for total anti-oxidative capabilities, mean activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione S-transferase; levels of reduced glutathione; malondialdehyde; and total sulfhydryl content.

RESULTS

All lenses in Group I were clear, whereas all lenses in Group II developed dense vacuolization and opacification. In Group III, 25% lenses revealed minimal vacuolization, and 75% showed no opacification or vacuolization. Total anti-oxidative capabilities and the mean activities of anti-oxidant enzymes superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione S-transferase; levels of glutathione; and total sulfhydryl content were elevated, and the level of malondialdehyde was decreased following treatment with danshensu compared with Group II.

CONCLUSION

The anti-oxidative properties of danshensu may play a major role in its contribution to the anticataract effect.

Renal protective effect of hesperidin on gentamicin-induced acute nephrotoxicity in male Wistar albino rats

OBJECTIVES

The aim of the study was to investigate the renoprotective effect of hesperidin (HDN), a citrus flavanoid with anti-oxidant properties against gentamicin (GEN)-induced nephrotoxicity in male Wistar albino rats.

METHODS

Urea, uric acid, creatinine, thiobarbituric acid reactive substances (TBARS), nitric oxide (NO), total cholesterol, free fatty acids, and triglyceride levels were measured in the serum. Further, glutathione (GSH), superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities were determined in the erythrocytes. Morphological changes in renal tissues were examined using light microscopy.

RESULTS

Acute renal injury was evidenced by: (1) increased serum urea, uric acid, creatinine, TBARS, and NO, (2) decreased SOD, GPx, and GSH levels, and (3) necrosis in proximal tubules and glomerular atrophy. HDN supplementation to GEN-induced rats significantly decreased serum urea, uric acid, creatinine, TBARS, NO generation, but SOD, GPx activities, and GSH content increased when compared with GEN alone. Moreover, HDN supplementation resulted in complete reversal of GEN-induced tubular necrosis, and an increase in total cholesterol, free fatty acids, and triglycerides to normal levels.

DISCUSSION

Our results suggested that HDN acts as a potent scavenger of free radicals in the kidney to prevent the toxic effects of GEN both at the biochemical and histopathological levels.

Nephroprotective Effect of Echinodorus macrophyllus Micheli on Gentamicin-Induced Nephrotoxicity in Rats

BACKGROUND/AIMS

Leaves of Echinodorus macrophyllus (EM), from the Alismataceae family, have been used in Brazilian folk medicine for their anti-inflammatory and diuretic properties. In this work, the diuretic and nephroprotective activities of crude extracts of EM were evaluated.

METHODS

Normal Wistar rats were given 0.9% NaCl containing either EM (10-300 mg/kg), furosemide (13 mg/kg) or arginine vasopressin (0.2 mg/kg). Thereafter, the rats were individually housed in metabolic cages, and urine volume was measured every 30 min for a total of 3 h. Acute kidney injury was induced by gentamicin (GM, 80 mg·kg(-1)·day(-1), b.i.d., 5 days). Along with GM, 0.9% NaCl (control) or EM (30 mg/kg) was given to the rats by gavage.

RESULTS

EM produced a dose-dependent reduction in urine elimination. EM was effective in reversing all GM-induced alterations such as polyuria and glomerular filtration rate reduction. The GM-induced morphological alterations were not observed when EM was given concomitantly with GM.

CONCLUSION

This study provides evidence that EM possesses nephroprotective effect which indicates that EM may have therapeutic applications in GM-induced acute kidney injury.

Copper compound induces autophagy and apoptosis of glioma cells by reactive oxygen species and JNK activation

BACKGROUND

Glioblastoma multiforme (GBM) is the most aggressive of the primary brain tumors, with a grim prognosis despite intensive treatment. In the past decades, progress in research has not significantly increased overall survival rate.

METHODS

The in vitro antineoplastic effect and mechanism of action of Casiopeina III-ia (Cas III-ia), a copper compound, on rat malignant glioma C6 cells was investigated.

RESULTS

Cas III-ia significantly inhibited cell proliferation, inducing autophagy and apoptosis, which correlated with the formation of autophagic vacuoles, overexpression of LC3, Beclin 1, Atg 7, Bax and Bid proteins. A decrease was detected in the mitochondrial membrane potential and in the activity of caspase 3 and 8, together with the generation of intracellular reactive oxygen species (ROS) and increased activity of c-jun NH(2)-terminal kinase (JNK). The presence of 3-methyladenine (as selective autophagy inhibitor) increased the antineoplastic effect of Cas III-ia, while Z-VAD-FMK only showed partial protection from the antineoplastic effect induced by Cas III-ia, and ROS antioxidants (N-acetylcysteine) decreased apoptosis, autophagy and JNK activity. Moreover, the JNK -specific inhibitor SP600125 prevented Cas III-ia-induced cell death.

CONCLUSIONS

Our data suggest that Cas III-ia induces cell death by autophagy and apoptosis, in part due to the activation of ROS -dependent JNK signaling. These findings support further studies of Cas III-ia as candidate for treatment of human malignant glioma.

Garlic-Supplemented Diet Attenuates Gentamicin-Induced Ototoxicity: An Experimental Study

Objectives:

Gentamicin sulfate is a potent aminoglycoside antibiotic associated with serious side effects, including ototoxicity. Garlic, with its intrinsic antioxidant activity, may prove beneficial in prevention of ototoxicity. In this study, we investigated the effect of a 4% garlic–supplemented diet on the ototoxicity induced by gentamicin in rats by using brain stem evoked response audiometry.

Methods:

Eighteen male Wistar rats with an intact Preyer's reflex and an initial weight of 220 to 260 g were randomly assigned to a group with gentamicin injection and garlic supplementation, a group with gentamicin injection without garlic supplementation, or a control group (6 rats each group). Gentamicin was given by intraperitoneal injection at 120 mg/kg body weight once daily for 16 days. The garlic-supplemented diet was prepared by adding pulverized whole garlic cloves to standard chow in a 4% proportion. After 21 days, hearing thresholds were evaluated by use of brain stem evoked response audiometry at 10 kHz.

Results:

The mean (±SD) amplitudes of the auditory thresholds (sensation level) measured by use of brain stem evoked response audiometry for the group with garlic supplementation, the group without garlic, and the control group were 43.3 ± 8.16, 78.0 ± 4.47, and 16.7 ± 5.16 dB sensation level, respectively. The differences were statistically significant (p < 0.05).

Conclusions:

A garlic-supplemented diet seems to attenuate aminoglycoside-induced hearing loss.

Floral extract of Tecoma stans: a potent inhibitor of gentamicin-induced nephrotoxicity in vivo

OBJECTIVE

To highlight the nephroprotective activity of ethyl acetate extract of dried flowers of Tecoma stans for its protective effects on gentamicin-induced nephrotoxicity in albino rats.

METHODS

For studying acute toxicity study, single oral dose of 5,000 mg ethyl acetate floral extract/kg body weight was administered to albino rats (five females, five males). Nephrotoxicity was induced in albino rats by intraperitoneal administration of gentamicin 80 mg/kg/day for eight days. Effect of concurrent administration of ethyl acetate floral extract of Tecoma stans at a dose of 100, 200 and 300 mg/kg/day given by oral route was determined using serum creatinine, serum uric acid, blood urea nitrogen and serum urea as indicators of kidney damage. The study groups contained six rats in each group. As nephrotoxicity of gentamicin is known to involve induction of oxidative stress, in vitro antioxidant activity and free radical-scavenging activity of this extract was also evaluated.

RESULTS

For acute toxicity testing both female and male rats administered with the extract at a dose of 5,000 mg/kg. The results showed no toxicity in terms of general behavior change, mortality, or change in gross appearance of internal organs (LD(50) > 5 000 mg/kg). It was observed that the ethyl acetate floral extract of Tecoma stans significantly protected rat kidneys from gentamicin-induced histopathological changes. Gentamicin-induced glomerular congestion, peritubular and blood vessel congestion, epithelial desquamation, accumulation of inflammatory cells and necrosis of the kidney cells were found to be reduced in the groups receiving the ethyl acetate floral extract of Tecoma stans along with gentamicin in a dose dependent manner. The floral extract also reduced the gentamicin-induced increase in serum creatinine, serum uric acid, blood urea nitrogen and serum urea levels (P >0.01).

CONCLUSIONS

The present study indicates a very important role of reactive oxygen species (ROS) and the relation to renal dysfunction and point to the therapeutic potential of Tecoma stans in gentamicin induced nephrotoxicity.

Garlic extract ameliorates renal and cardiopulmonary injury in the rats with chronic renal failure

Chronic renal failure (CRF) is associated with oxidative stress that promotes production of reactive oxygen species and cytokine release. We aimed to investigate the possible protective and antioxidant effects of aqueous garlic extract (AGE) in a rat model of CRF. Male Sprague-Dawley rats were randomly assigned as either CRF group with 5/6 reduction in the renal mass or sham-operated control group. CRF group received either saline or AGE (250 mg/kg/day/1 mL) orally for 3 weeks. At the end of the 3 weeks, rats were decapitated and trunk blood was collected. Creatinine, blood urea nitrogen (BUN) and lactate dehydrogenase (LDH) activity, and TNF-α and IL-1β levels were measured in the serum samples, while malondialdehyde (MDA), glutathione (GSH) levels, and myeloperoxidase (MPO) activity were determined in the kidney, lung, and heart samples. CRF caused significant decreases in tissue GSH, which were accompanied with significant increases in MDA levels and MPO activities, while the circulating levels of the LDH activity, creatinine, BUN, TNF-α, and IL-1β were elevated. AGE treatment alleviated CRF-induced oxidative changes in the injured tissues, while CRF-induced elevations in the blood levels of the pro-inflammatory cytokines and LDH were reduced. In conclusion, CRF-induced oxidative tissue injury occurs via the activation of pro-inflammatory mediators and by neutrophil infiltration into tissues and that the protective effects of garlic on CRF-induced injury can be attributed to its ability to inhibit neutrophil infiltration and pro-inflammatory mediators. These findings suggest that garlic, as a supplementary to diet, may have a potential therapeutic use in delimitating the systemic oxidant effects of CRF on remote organs.

Glutathione peroxidase-1 in health and disease: from molecular mechanisms to therapeutic opportunities

Reactive oxygen species, such as superoxide and hydrogen peroxide, are generated in all cells by mitochondrial and enzymatic sources. Left unchecked, these reactive species can cause oxidative damage to DNA, proteins, and membrane lipids. Glutathione peroxidase-1 (GPx-1) is an intracellular antioxidant enzyme that enzymatically reduces hydrogen peroxide to water to limit its harmful effects. Certain reactive oxygen species, such as hydrogen peroxide, are also essential for growth factor-mediated signal transduction, mitochondrial function, and maintenance of normal thiol redox-balance. Thus, by limiting hydrogen peroxide accumulation, GPx-1 also modulates these processes. This review explores the molecular mechanisms involved in regulating the expression and function of GPx-1, with an emphasis on the role of GPx-1 in modulating cellular oxidant stress and redox-mediated responses. As a selenocysteine-containing enzyme, GPx-1 expression is subject to unique forms of regulation involving the trace mineral selenium and selenocysteine incorporation during translation. In addition, GPx-1 has been implicated in the development and prevention of many common and complex diseases, including cancer and cardiovascular disease. This review discusses the role of GPx-1 in these diseases and speculates on potential future therapies to harness the beneficial effects of this ubiquitous antioxidant enzyme.

Reno-protective role of flunarizine (mitochondrial permeability transition pore inactivator) against gentamicin induced nephrotoxicity in rats

This study was aimed to evaluate the role of flunarizine on gentamicin (GEM) induced nephrotoxicity in rat. Administration of GEM (40 mg/kg, s.c. for 10 consecutive days) significantly increased blood urea nitrogen (BUN), N-acetyl β-d-glucosaminidase (NAG), thiobarbituric acid reactive substances (TBARS) and total calcium whereas, decreased body weight, fractional excretion of sodium (FrNa), creatinine clearance (CrCl), reduced glutathione (GSH), mitochondrial cytochrome c oxidase (Cyt-C oxidase) and ATP levels resulting in nephrotoxicity. Further, flunarizine (100, 200 and 300 µmol/kg, p.o.) was administered to evaluate its renoprotective effect against GEM induced nephrotoxicity and the results were compared with cylcosporin A (CsA, 50 µmol/kg, p.o.). Flunarizine resulted in the attenuation of renal dysfunction and oxidative marker changes in rats subjected to GEM induced nephrotoxicity in a dose dependent manner. Medium and higher doses of flunarizine produced significant renal protective effect which was comparable to cyclosporin A. The results of this study clearly revealed that flunarizine protected the kidney against the nephrotoxic effect of GEM via mitochondrial permeability transition pore (MPTP) inactivation potential.

Diazepam blocks striatal lipid peroxidation and improves stereotyped activity in a rat model of acute stress

In this work, the effect of a single dose of diazepam was tested on different markers of oxidative damage in the striatum of rats in an acute model of immobilization (restraint) stress. In addition, the locomotor activity was measured at the end of the restraint period. Immobilization was induced to animals for 24 hr, and then, lipid peroxidation, superoxide dismutase activity and content, and mitochondrial function were all estimated in striatal tissue samples. Corticosterone levels were measured in serum. Diazepam was given to rats as a pre-treatment (1 mg/kg, i.p.) 20 min. before the initiation of stress. Our results indicate that acute stress produced enhanced striatal levels of lipid peroxidation (73% above the control), decreased superoxide dismutase activity (54% below the control), reduced levels of mitochondrial function (35% below the control) and increased corticosterone serum levels (86% above the control). Pre-treatment of stressed rats with diazepam decreased the striatal lipid peroxidation levels (68% below the stress group) and improved mitochondrial function (18% above the stress group), but only mild preservation of superoxide dismutase activity was detected (17% above the stress group). In regard to the motor assessment, only the stereotyped activity was increased in the stress group with respect to control (46% above the control), and this effect was prevented by diazepam administration (30% below the stress group). The preventive actions of diazepam in this acute model of stress suggest that drugs exhibiting anxiolytic and antioxidant properties might be useful for the design of therapies against early acute phases of physic stress.

Antidepressant-like effect of a Ginkgo biloba extract (EGb761) in the mouse forced swimming test: role of oxidative stress

EGb761 is a well-defined mixture of active compounds extracted from Ginkgo biloba leaves. This extract is used clinically due to its neuroprotective effects, exerted probably via its potent antioxidant or free radical scavenger action. Previous studies suggest that oxidative stress, via free radical production, may play an important role in depression and animal models for depression-like behavior. Preclinical studies have suggested that antioxidants may have antidepressants properties. The aim of this study was to investigate the antidepressant-like of EGb761 due to its antioxidant role against oxidative stress induced in the forced swimming test, the most widely used preclinical model for assessing antidepressant-like behavior. Male BALB/c mice were pretreated with EGb761 (10mg/kg, ip) daily for 17 days followed by the forced swimming test and spontaneous locomotor activity. Animals were sacrificed to evaluate lipid peroxidation, different antioxidant enzyme activities, serotonin and dopamine content in midbrain, hippocampus and prefrontal cortex. EGb761 significantly decreased the immobility time (39%) in the forced swimming test. This antidepressant-like effect of EGb761 was associated with a reduction in lipid peroxidation and superoxide radical production (indicated by a downregulation of Mn-superoxide dismutase activity), both of which are indicators of oxidative stress. The protective effect of EGb761 is not related to excitatory or inhibitory effects in locomotor activity, and was also associated with the modulation of serotonergic and dopaminergic neurotransmission. It is suggested that EGb761 produces an antidepressant-like effect, and that an antioxidant effect against oxidative stress may be partly responsible for its observed neuroprotective effects.

Early changes in oxidative stress markers in a rat model of acute stress: effect of l-carnitine on the striatum

This work focuses on the effect of acute stress on different markers of oxidative stress and mitochondrial dysfunction in the rat striatum. In addition, the effect of a single dose of l-carnitine (l-CAR, 300 mg/kg, i.p.) was evaluated in these animals. Immobilization (restraint) stress was induced to rats for 24 hr. The levels of lipid peroxidation (LP) and mitochondrial function (MF), as well as the superoxide dismutase (SOD) activity and content and reduced glutathione (GSH) levels, were all measured in striatal samples of animals subjected to stress. Our results indicate that acute stress is able to increase the striatal LP and reduced the levels of MF, while significantly lowered the manganese superoxide dismutase (Mn-SOD) activity. No changes were observed in the total striatal content of SOD, nor in GSH levels, but serum corticosterone content was increased by stress. l-CAR exhibited partial protective effects on the immobilized group, reducing the striatal LP and recovering the striatal MF and Mn-SOD activity. Our results suggest that acute restraint stress brings an accurate model for early pro-oxidant responses that can be targeted by broad-spectrum antioxidants like l-CAR.

Protective effects of erdosteine on amikacin induced visual evoked potentials and lipid peroxidation alterations

PURPOSE

We aimed at investigating the effect of erdosteine administration on amikacin induced visual evoked potentials (VEPs) alterations in rats.

METHODS

For this purpose, forty male Wistar rats were divided into 4 groups: control, amikacin treated, erdosteine treated, and amikacin + erdosteine treated. Amikacin (600 mg/kg/day) was applied as a single dose of intramuscular injection for 14 days, and 10 mg/kg/day erdosteine was given by gastric gavage for the same period. We recorded all VEP components and measured plasma thiobarbituric acid reactive substance (TBARS) levels in all groups.

RESULTS

Amikacin increased the latencies of all VEP components (P1, N1, P2, N2, and P3) and elevated plasma TBARS levels compared with control and erdosteine treated rats (p < 0,01). However, prolonged latencies of VEP components in amikacin treated rats returned to control levels after erdostein administration. Treatment of amikacin and erdosteine together significantly decreased plasma TBARS levels (0.05 ± 0.018 nmol/g protein) compared with amikacin group (0.12 ± 0.038 nmol/g protein).

CONCLUSIONS

These results show that erdosteine has a protective effect on amikacin induced changes in the visual system.

S-Allylcysteine, a garlic compound, protects against oxidative stress in 1-methyl-4-phenylpyridinium-induced parkinsonism in mice

S-Allylcysteine (SAC), the most abundant organosulfur compound in aged garlic extract, has multifunctional activity via different mechanisms and neuroprotective effects that are exerted probably via its antioxidant or free radical scavenger action. The 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated mouse has been the most widely used model for assessing neuroprotective agents for Parkinson's disease. 1-Methyl-4-phenylpyridinium (MPP(+)) is the stable metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, and it causes nigrostriatal dopaminergic neurotoxicity. Previous studies suggest that oxidative stress, via free radical production, is involved in MPP(+)-induced neurotoxicity. Here, we report on the neuroprotective effect of SAC against oxidative stress induced by MPP(+) in the striatum of C57BL/6J mice. Mice were pretreated with SAC (125 mg/kg ip) daily for 17 days, followed by administration of MPP(+) (0.72 mg/kg icv), and were sacrificed 24 h later to evaluate lipid peroxidation, different antioxidant enzyme activities, spontaneous locomotor activity and dopamine (DA) content. MPP(+) administration resulted in a significant decrease in DA levels in the striatum. Mice receiving SAC (125 mg/kg ip) had significantly attenuated MPP(+)-induced loss of striatal DA levels (32%). The neuroprotective effect of SAC against MPP(+) neurotoxicity was associated with blocked (100% of protection) of lipid peroxidation and reduction of superoxide radical production - indicated by an up-regulation of Cu-Zn-superoxide dismutase activity - both of which are indices of oxidative stress. Behavioral analyses showed that SAC improved MPP(+)-induced impairment of locomotion (35%). These findings suggest that in mice, SAC attenuates MPP(+)-induced neurotoxicity in the striatum and that an antioxidant effect against oxidative stress may be partly responsible for its observed neuroprotective effects.

Malondialdehyde and superoxide dismutase correlate with FEV(1) in patients with COPD associated with wood smoke exposure and tobacco smoking

Tobacco smoking is the primary risk factor for chronic obstructive pulmonary disease (COPD). However, recent epidemiological studies have established domestic exposure to wood smoke and other biomass fuels as additional important risk factors, characteristic in developing countries. Oxidative stress is one of the mechanisms concerned with pathogenesis of COPD. However, the molecular mechanisms involved in the onset and progress of COPD associated with biomass and specifically that derived from wood smoke exposure remain unknown. We analyzed the relationship between forced expiratory volume in first second (FEV(1)) with plasma malondialdehyde (MDA) concentration and activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione-S-transferase (GST) in COPD patients associated with wood smoke (WSG; n = 30), tobacco smoking (TSG; n = 30), and healthy control subjects (HCG; n = 30). Differences between FEV(1) from WSG and TSG (58 +/- 22% and 51 +/- 24%, respectively) with HCG (100 +/- 6%) were observed (P < 0.01). Plasma MDA concentration was higher in both WSG and TSG (1.87 +/- 0.81 and 1.68 +/- 0.82 nmol/mL, respectively) compared with HCG (0.42 +/- 0.17 nmol/mL; P < 0.01). SOD activity showed a significant increase in both WSG and TSG (0.36 +/- 0.12 and 0.37 +/- 0.13 U/mL) compared with HCG (0.19 +/- 0.04 U/mL; P < 0.01). No differences were shown regarding GPx, GR, and GST activities between COPD and control groups. Inverse correlations were founded between MDA and SOD with FEV(1) in both COPD patients and control subjects (P < 0.001). These results indicate a role for oxidative stress in COPD associated with wood smoke similar to that observed with tobacco smoking in subjects who ceased at least 10 years previous to this study.

Pentoxifylline ameliorates glomerular basement membrane ultrastructural changes caused by gentamicin administration in rats

Gentamicin is commonly used for the treatment of severe gram negative bacterial infections but inevitably cause renal failure during prolonged use. The aim of our study was to emphasize protective effects of pentoxifylline on glomerular basement membrane (GBM) alterations induced by gentamicin in rats. Experiments were done on 40 male Wistar rats divided in three experimental groups. GM-group was treated daily with gentamicin in dose of 100 mg/kg during 8 days. PTX-group was treated daily with pentoxifylline in dose of 45 mg/kg and the same dose of gentamicin as in GM-group during 8 days. The control group received 1 ml/day saline intraperitoneally. Morphometric parameter measured during the analysis was glomerular basement membrane thickness. In GM-group of animals glomeruli were enlarged and GMB was diffusely and unequally thickened with neutrophil cells infiltration. In proximal tubules epithelial cells, vacuolization of cytoplasm with coagulation-type necrosis were observed. In PTX-group of animals glomeruli were somewhat enlarged and GBM was thickened only in some segments. Coagulation-type necrosis was not found. Blood urea and serum creatinine concentration in GM-group were significantly elevated in comparison with PTX-group while potassium level was decreased. Our results suggest that PTX has protective effects on GBM and proximal tubules in GM-treated rats.

Comparative evaluation of adenosine deaminase activity in cerebral cortex and hippocampus of young and adult rats: effect of garlic extract (Allium sativum L.) on their susceptibility to heavy metal exposure

Adenosine plays an important neuromodulatory role in the central nervous system, and adenosine deaminase is an important enzyme in the degradation of adenine nucleotides. Methylmercury is the most prevalent form of mercury found in the environment. Methylmercury neurotoxicity has been correlated to the production of reactive oxygen species. In this study, its potential pathogenic effects were investigated in vitro in cerebral cortex and hippocampus of rats. We first observed that adenosine deaminase activity was higher in young rat brains when compared to the 60-day-old rats and was higher in hippocampus when compared to the cortex. Methylmercury (0.1, 1.0, 20 microM) inhibited adenosine deaminase activity in 7- and 60-day-old rats in a concentration-dependent manner. We have demonstrated that methylmercury-induced inhibition was antagonized by garlic alcoholic extract, but sodium selenate did not alter enzyme activity. In addition, glutathione and dithiothreitol restored the methylmercury-induced decrease of adenosine deaminase activity. These results demonstrated that there are age-related changes in adenosine deaminase activity and that thiol agents may contribute to the maintenance of adenosine deaminase activity and may be important in the neuromodulation of adenosine. Garlic alcoholic extract may be effective in reducing the effect of methylmercury-induced adenosine deaminase, which may be due to its sulphur-containing compounds.

Protective effects of nigella sativa against gentamicin-induced nephrotoxicity in rats

The aim of this study was focused on investigating the possible protective effect of NS against GS-induced nephrotoxicity. Twenty four Wistar-albino rats were divided into four equal groups as follows: control group, GS group (100mg/kg intraperitoneal - i.p.), NSL+GS group (0.2 ml/kg+100mg/kg i.p.) and NSH+GS group (0.4 ml/kg+100mg/kg i.p.). Plasma creatinine and urea levels significantly increased as a result of nephrotoxicity in the GS group. Also, creatinine and urea levels significantly decreased in NSL+GS and NSH+GS groups. In the GS group, plasma MDA and NO levels increased significantly (p<0.05) and erythrocyte SOD and GSH-Px activities decreased significantly (p<0.05) when compared with control group. NS administration with GS injection resulted in significantly decreased MDA and NO generation and increased SOD and GSH-Px activities when compared with GS group. Proximal tubular necrosis, vacuolation, desquamation and degeneration in epithelial cells of the proximal tubules, hyaline casts in tubular lumen, mononuclear cell infiltration, glomerular and basement membrane alterations were histopathologically detected in the kidneys of the GS group. Co-treatments with NS (low and high dose) considerably decreased the renal damage when compared with the GS group. In conclusion, NS acts in the kidney as a potent scavenger of free radicals to prevent the toxic effects of GS both in the biochemical and histopathological parameters.

Diallyl sulfide enhances antioxidants and inhibits inflammation through the activation of Nrf2 against gentamicin-induced nephrotoxicity in Wistar rats

The protective role of diallyl sulfide (DAS) in attenuating gentamicin-induced nephrotoxicity has been reported earlier. However, the mechanism of induction of antioxidants by DAS in nephrotoxicity remains elusive. This study is aimed to elucidate the role of a transcription factor, Nuclear factor E2-related factor 2 (Nrf2) in inducing antioxidants and phase II enzymes during gentamicin toxicity in Wistar rats. DAS was administered intraperitoneally at a dosage of 150 mg/kg body weight once daily for 6 days. Gentamicin was administered intraperitoneally at a dosage of 100 mg/kg body weight, once daily for 6 days. Gentamicin-induced rats showed a significant increase in the levels of kidney markers and the activities of urinary marker enzymes, which was reversed upon treatment with DAS. A significant increase in kidney myeloperoxidase (MPO) and lipid peroxidation (LPO) levels was observed in gentamicin-induced rats, which was reduced upon treatment with DAS. Gentamicin-induced rats also showed a significant decrease in the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST) and quinone reductase (QR) in rat kidney, which was increased upon treatment with DAS. Immunohistochemical studies in gentamicin-induced rats demonstrated a marked increase in the immunoreactivity of inducible nitric oxide synthase (iNOS), nuclear transcription factor (NF-kappaB) and tumor necrosis factor alpha (TNF-alpha) that were reduced after treatment with DAS. Further, the involvement of Nrf2 in antioxidant induction was analyzed by Western blot and immunofluorescence. To conclude, DAS enhances antioxidants and suppresses inflammatory cytokines through the activation of Nrf2, thereby protecting the cell against oxidative stress induced by gentamicin.

Efficacy of the combination of N-acetylcysteine and desferrioxamine in the prevention and treatment of gentamicin-induced acute renal failure in male Wistar rats

BACKGROUND

Oxidative stress and the formation of aminoglycoside-iron complexes through iron-dependent Fenton reaction have been proposed to be the major mechanisms in the development of GM-induced acute renal failure (ARF); however, the efficacy of the combination of N-acetylcysteine (NAC) and desferrioxamine (DFX) in the prevention and the treatment of GM-induced ARF has not previously been investigated.

METHODS

In the prevention protocol, adult male Wistar rats received gentamicin (GM) [70 mg/kg, intraperitoneally (i.p), each 12 h for 7 days], NAC (20 mg/kg, sc, each 8 h for 7 days) and/or DFX (20 mg/kg, sc, at first, fourth and seventh days). In the treatment protocol animals received GM for 7 days. Additionally, animals received NAC and or DFX starting in the fourth day after GM administration. Parameters of renal function had been evaluated 24 h, 4 and 8 days after the beginning of GM administration in the prevention protocol and in Days 5 and 8 in the treatment protocol. At the end of experiment, lipid peroxidation (TBARS assay) and protein oxidation (protein carbonyls levels) formation were evaluated in kidney tissue as oxidative damage parameters.

RESULTS

In the prevention protocol, GM-induced ARF was prevented by the NAC and DFX association. Lipid peroxidation was attenuated by both antioxidant treatments, but the effects of NAC plus DFX were of greater magnitude. In the treatment protocol, plasma markers of renal injury were improved only in the NAC group, despite the similar antioxidant effect of both NAC, DFX and NAC plus DFX.

CONCLUSION

Although the combination of NAC and DFX was more effective in the prevention protocol, the use of NAC alone seemed to be superior to NAC-DFX combination, in the treatment of GM-induced ARF in adult male Wistar rats.

Role of oxidative and nitrosative stress in cisplatin-induced nephrotoxicity

cis-Diamminedichloroplatinum (II) (cisplatin) is an important chemotherapeutic agent useful in the treatment of several cancers; however, it has several side effects such as nephrotoxicity. The role of the oxidative and nitrosative stress in cisplatin-induced nephrotoxicity is additionally supported by the protective effect of several free radical scavengers and antioxidants. Furthermore, in in vitro experiments, antioxidants or reactive oxygen species (ROS) scavengers have a cytoprotective effect on cells exposed to cisplatin. Recently, the participation of nitrosative stress has been more explored in cisplatin-induced renal damage. The use of a water-soluble Fe(III) porphyrin complex able to metabolize peroxynitrite (ONOO(-)) has demonstrated that this anion contributes to both in vivo and in vitro cisplatin-induced toxicity. ONOO(-) is produced when nitric oxide (NO*) reacts with superoxide anion (O(2)(*-)); currently, there are evidences suggesting alterations in NO* production after cisplatin treatment and the evidence appear to NO* has a toxic effect. This article goes through current evidence of the mechanism by more than a few compounds have beneficial effects on cisplatin-induced nephrotoxicity, contribute to understanding the role of oxidative and nitrosative stress and suggest several points as part of the mechanism of cisplatin toxicity.

EGb761 protects against nigrostriatal dopaminergic neurotoxicity in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced Parkinsonism in mice: role of oxidative stress

1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) causes nigrostriatal dopaminergic neurotoxicity and behavioral impairment in rodents. Previous studies suggest that oxidative stress, via free radical production, is involved in MPTP-induced neurotoxicity. The MPTP-treated mouse has been the most widely used model for assessing neuroprotective agents for Parkinson's disease. It has been reported previously that EGb761 prevents dopaminergic neurotoxicity of MPTP. This compound is multifunctional via different mechanisms. Here, we report the neuroprotective effect of EGb761 against oxidative stress induced by MPTP in C57BL/6J mice. EGb761 is a patented and well-defined mixture of active compounds extracted from Ginkgo biloba leaves, with neuroprotective effects, exerted probably via its antioxidant or free radical scavenger action. MPTP administration resulted in a significant decrease in striatal dopamine levels and tyrosine hydroxylase immunostaining in the striatum and substantia nigra pars compacta. Mice receiving EGb761 had significantly attenuated MPTP-induced loss of striatal dopamine levels and tyrosine hydroxylase immunostaining in the striatum and substantia nigra pars compacta. The neuroprotective effect of EGb761 against MPTP neurotoxicity is associated with blockade of lipid peroxidation and reduction of superoxide radical production (indicated by a down-regulation of Mn-superoxide dismutase activity), both of which are indices of oxidative stress. Behavioral analyses showed that EGb761 improved MPTP-induced impairment of locomotion in a manner that correlated with enhancement of striatal dopamine levels. These findings suggest that, in mice, EGb761 attenuates MPTP-induced neurodegeneration of the nigrostriatal pathway and that an inhibitory effect against oxidative stress may be partly responsible for its observed neuroprotective effects.

Protective effects of melatonin on renal failure in pinealectomized rats

AIM

The purpose of the current study was to investigate the effects melatonin on renal function.

METHODS

The histological appearance of the kidney and malondialdehyde, nitric oxide, glutathione and superoxide dismutase contents were determined. Serum creatinine and blood urea nitrogen levels were also assayed. Rats were divided as: Sham, pinealectomized (Px) and pinealectomized and treated with melatonin.

RESULTS

In Px group, malondialdehyde and nitric oxide levels were elevated when compared with the sham group. The Px group exhibited reduced superoxide dismutase activity and glutathione content. All of these harmful changes were restored by melatonin. Melatonin also ameliorated serum creatinine and blood urea nitrogen levels related to renal injury. The score for glomerular, tubular and interstitial changes was significantly higher in the Px group. Melatonin supplementation significantly reduced these parameters.

CONCLUSIONS

This protective effect may be associated with both melatonin's lipophilic and hydrophilic effects, thus providing on-site protection against free radical mediated damage.

Role of garlic in the prevention of ischemia-reperfusion injury

Garlic in different forms has antioxidant properties. These properties are shown to be due to the existence of compounds such as water soluble organosulfur compounds, S-allylcysteine and lipid soluble compounds like diallyl sulfide. The in vivo and in vitro ischemia reperfusion studies showed that prophylactic administration of aqueous garlic prior to ischemia reperfusion inhibit lipid peroxidation and prevent depletion in glutathione through its compounds that led to functional recovery. Its ability to inhibit neutrophil migration could suppress fibrosis formation. These preventive effects are seen in models that studied organs such as kidney and liver with functional recovery. Organ system specific activity such as angiotensin converting enzyme-inhibiting activity contributes to a cardioprotective and blood pressure lowering effect. Future studies should focus on post ischemia reperfusion administration of garlic to explore its rescue potential rather than prophylactic impact. Bench research findings should be translated into clinical use through human studies.

Protective effects of apocynin against cisplatin-induced oxidative stress and nephrotoxicity

Cis-diamminedichloroplatinum (II) (cisplatin) is an effective chemotherapeutic agent successfully used in the treatment of a wide range of tumors; however, nephrotoxicity has restricted its clinical use. Several studies have shown that reactive oxygen species are involved in cisplatin-induced nephrotoxicity, including hydrogen peroxide, hydroxyl radical and superoxide anion (O(2)(-)). The source of O(2)(-) in cisplatin-induced renal damage has not been established. The aim of this study was to investigate if NADPH oxidase is involved in cisplatin-induced nephrotoxicity using apocynin, a widely used NADPH oxidase inhibitor. Rats were studied 3 days after a single injection of cisplatin (7.5mg/kg, i.p.). Apocynin was given in the drinking water (2g/L) 7 days before and 3 days after cisplatin injection. Apocynin treatment was able to ameliorate the renal histological damage and the increase in blood urea nitrogen, serum creatinine, and urinary excretion of total protein, N-acetyl-beta-d-glucosaminidase and glutathione-S-transferase induced by cisplatin. In addition, the protective effect of apocynin was associated with the amelioration of cisplatin-induced oxidative and nitrosative stress. Our data suggest that O(2)(-) derived from NADPH oxidase triggers some of the side effects due to cisplatin administration.

Novel evidence suggesting an anti-oxidant property for erythropoietin on vancomycin-induced nephrotoxicity in a rat model

1. The aim of the present study was to investigate the role of oxidative stress in renal injury and to determine whether erythropoietin (EPO) acts as an anti-oxidant in vancomycin (VCM)-induced renal impairment. 2. Twenty-four rats were divided into three groups as follows: (i) control (Group 1); (ii) VCM treated (Group 2); and (iii) VCM + EPO treated (Group 3). Vancomycin (200 mg/kg, i.p.) was administered to Groups 2 and 3 for 7 days. Erythropoietin (150 IU/kg, i.p.) treatment was started 24 h before VCM and lasted for 7 days. On Day 8, renal tissues were excised and blood samples were collected. Serum creatinine and blood urea nitrogen were measured, along with renal malondialdehyde (MDA) levels, superoxide dismutase (SOD) and catalase (CAT) activity and tissue VCM levels. The kidneys were examined for any histopathological changes. 3. Renal MDA levels were found to be increased, whereas SOD and CAT activity was decreased, in the VCM-treated group compared with the control group. There was a marked decrease in MDA levels and an increase in SOD activity, but not CAT activity, after VCM + EPO treatment. Marked histopathological alterations, including interstitial oedema, tubular dilatation, tubular epithelial cell desquamation and vacuolization, were observed in VCM-treated rats. Histopathological changes were significantly improved after EPO administration. 4. In conclusion, the present data suggest that oxidative stress plays an important role in VCM-induced nephrotoxicity. Erythropoietin seems to act as an anti-oxidant, diminishing the toxic oxidative effects of VCM on renal tissues.

Protective effects of aqueous garlic extract in reducing water avoidance stress-induced degeneration of the stomach, ileum, and liver: morphological and biochemical study

We investigated the effect of aqueous garlic extract (AGE) on water avoidance stress (WAS)-induced degeneration of the gastric and ileal mucosa and liver parenchyma. Wistar albino rats were exposed to WAS (WAS group) for 5 days. After exposure of the animals to WAS, a 1 ml/kg aqueous garlic extract (AGE) was injected i.p. (WAS+AGE group). The stomach, ileum, and liver samples were investigated under light microscope for general morphology. Topography of gastric and ileal mucosa was investigated by scanning electron microscopy, and hepatocyte ultastructure by transmission electron micsroscopy. Malondialdehyde (MDA) and glutathione (GSH) levels of all tissues were also determined. In the WAS group, the epithelium of the stomach showed ulceration in some areas, dilatations of the gastric glands, and degeneration of gastric glandular cells. Severe vascular congestion and degeneration of ileal epithelium were observed. Prominent vascular congestion and dilated sinusoids, activated Kupffer cells with prominent morphology, dilated granular endoplasmic reticulum membranes, and focal picnotic nuclei were observed in liver parenchyma. AGE treatment reduced the degeneration of the gastric and ileal mucosa and liver parenchyma. Increased MDA levels and decreased GSH levels in the WAS group were reversed to control values after AGE treatment. Based on these results, AGE treatment significantly prevented WAS-induced degeneration in both morphology and biochemistry of gastrointestinal mucosa and liver parenchyma due to its potent free radical scavenging and antioxidant properties.

Hypochlorous acid scavenging capacity of garlic

The ability of the following aqueous garlic extracts to scavenge hypochlorous acid (HOCl) was studied: (a) unheated extract of raw garlic (RG), (b) heated extract of raw garlic (HRG), (c) extract of boiled garlic cloves (BG) and (d) extract of microwave-treated garlic cloves (MG). The HOCl scavenging activity was evaluated following changes in the absorption spectrum of catalase (370-450 nm). RG, HRG and BG scavenged HOCl in a concentration-dependent way: the IC(50) (mg/mL) values for RG, HRG and BG were 0.339 +/- 0.028, 0.632 +/- 0.030 and 0.690 +/- 0.031, respectively. The HOCl scavenging ability of garlic was significantly decreased when garlic cloves or the extract of raw garlic were heated (BG and HRG, respectively); this scavenging ability was eliminated when garlic was subjected to microwave heating (MG). The IC(50) value for the reference compound, ascorbic acid, was 0.500 +/- 0.049 mg/mL. In summary, raw garlic concentration-dependently scavenged HOCl; this ability was eliminated in extracts of microwave-treated garlic cloves but not in heated extracts of raw garlic or extracts of boiled garlic cloves.

Protective effects of garlic powder against potassium dichromate-induced oxidative stress and nephrotoxicity

Potassium dichromate (K(2)Cr(2)O(7))-induced nephrotoxicity is associated with oxidative stress. In the present work the effect of garlic powder, a recognized antioxidant, on K(2)Cr(2)O(7)-induced nephrotoxicity and oxidative stress was studied. Rats were fed a 2% garlic powder diet for 1 month. A single injection of K(2)Cr(2)O(7) (15 mg/kg) to rats induced tubule interstitial damage and an increase in the following markers of renal injury 2 days later: blood urea nitrogen (4.6-fold), serum creatinine (9.7-fold), proteinuria (35.9-fold), urinary excretion of N-acetyl-beta-d-glucosaminidase (12.9-fold) and glutathione-S-transferase (2.3-fold) and a decrease of 65% in serum glutathione peroxidase activity. In addition, K(2)Cr(2)O(7) injection increased the following nitrosative and oxidative stress markers in kidney: 3-nitrotyrosine (1.9-fold), 4-hydroxy-2-nonenal (2.1-fold), malondialdehyde (1.8-fold) and protein carbonyl content (1.7-fold). It was found that garlic powder feeding was able to prevent by 44-71% the alterations in the markers of renal injury studied, by 55% the histological damage, and by 47-100% the increase in markers of oxidative and nitrosative stress. It is concluded that the ability of garlic powder to ameliorate K(2)Cr(2)O(7)-induced renal injury is associated with its antioxidant properties. Our data support the use of garlic powder as a renoprotective agent.

Renoprotective and antihypertensive effects of S-allylcysteine in 5/6 nephrectomized rats

Progressive renal damage and hypertension are associated with oxidative and nitrosative stress. On the other hand, S-allylcysteine (SAC), the most abundant organosulfur compound in aged garlic extract (AG), has antioxidant properties. The effects of SAC and AG on blood pressure, renal damage, and oxidative and nitrosative stress were studied in five-sixths nephrectomized rats treated with SAC (200 mg/kg ip) and AG (1.2 ml/kg ip) every other day for 30 days. Proteinuria and serum creatinine and blood urea nitrogen concentrations were measured on days 0, 5, 10, 15, and 30, and systolic blood pressure was recorded on days 0, 15, and 30. The degree of glomerulosclerosis and tubulointerstitial damage, the immunostaining for inducible nitric oxide synthase, 3-nitrotyrosine, poly(ADP-ribose), and the subunits of NADPH oxidase p22phox and gp91phox, and the activity of SOD were determined on day 30. SAC and AG reduced hypertension, renal damage, and the abundance of inducible nitric oxide synthase, 3-nitrotyrosine, poly(ADP-ribose), p22phox, and gp91phox and increased SOD activity. Our data suggest that the antihypertensive and renoprotective effects of SAC and AG are associated with their antioxidant properties and that they may be used to ameliorate hypertension and delay the progression of renal damage.

Propofol attenuation of renal ischemia/reperfusion injury involves heme oxygenase-1

AIM

To examine the protective effect of propofol in renal ischemia/reperfusion (I/R) injury and the role of heme oxygenase-1 (HO-1) in this process.

METHODS

Sprague-Dawley rats were randomly divided into 3 groups: (i) sham-operated group; (ii) I/R group; and (iii) propofol group. Bilateral renal warm ischemia for 45 min was performed. After 2, 6, and 24 h reperfusion, blood samples and kidneys were collected for assessment of renal injury, and HO-1 expressions were analyzed by immunohistochemical analysis, RT-PCR and Western blotting.

RESULTS

Blood urea nitrogen and serum creatinine levels in the propofol group were significantly lower than that in the I/R group at 24 h after reperfusion. The mean histological score by Palleros standard showed that propofol significantly attenuated renal I/R injury after 6 h reperfusion. Propofol increased HO-1 mRNA and protein levels 2 h after reperfusion, whereas HO-1 expressions were present at exceedingly low levels in the I/R group and the sham-operated group at same time point. Propofol also markedly increased HO-1 mRNA and protein levels than I/R at 6 and 24 h after reperfusion.

CONCLUSION

These results suggest that propofol mitigates renal I/R injury in rats. This protection may be partly through the induction of the HO-1 expression.

Effect of heating on peroxynitrite scavenging capacity of garlic

The ability to scavenge peroxynitrite (ONOO(-)) was studied in the following aqueous garlic extracts: (a) unheated extract of garlic powder (GP), (b) heated extract of garlic powder (HGP), (c) unheated extract of raw garlic (RG), (d) heated extract of raw garlic (HRG), (e) extract of boiled garlic cloves (BG), (f) extract of microwave-treated garlic cloves (MG), and (g) extract of pickled garlic (PG). All the extracts scavenged ONOO(-) in a concentration-dependent way. IC(50) (mg/mL) values for each extract were 0.30+/-0.02 and 0.35+/-0.04 for GP and HGP, respectively; and 0.84+/-0.08, 0.59+/-0.04, 0.76+/-0.09, 1.71+/-0.19, and 1.45+/-0.07 for RG, HRG, BG, MG, and PG, respectively. The ONOO(-) scavenging capacity (IC(50) values) was not decreased in HGP (vs. GP, p>0.05) and in HRG and BG (p>0.05 vs. RG). In contrast, the ONOO(-) scavenging capacity decreased in MG and PG (vs. RG, p<0.001). The IC(50) values for the reference compounds nordihydroguiaretic acid and penicillamine were 1.1 and 4.5mug/mL. The heating before or after garlic cutting was unable to eliminate the capacity of the extracts to scavenge ONOO(-); this capacity was significantly decreased in PG and MG.

Gentamicin-induced nephrotoxicity in rats ameliorated and healing effects of resveratrol

In this study, we aimed to investigate the possible protective effect of resveratrol on gentamicin induced nephrotoxicity. Experiments were carried out in male Wistar rats weighing 200-250 g. Gentamicin sulfate (80 mg/kg per day i.p.), resveratrol (10 mg/kg per day i.p.) and gentamicin together with resveratrol were administered for 6 d. The animals were sacrificed 24 h after the last injection. Urine, blood samples and tissue samples were collected from the animals on the seventh day of the treatment before they were sacrificed. Kidneys were collected for histopathological studies and fixed in 10% buffered formalin solution. Tissue samples were stored at -70 degrees C in liquid nitrogen for the determination of glutathione (GSH), glutathione-S-transferase (GST), malondialdehyde (MDA) and catalase (CAT). Glutathione assay was determined by the method of Beutler et al. GST amounts were measured by the method of Habig et al. Catalase activity was tested by Aebi's method and MDA was determined according to Thayer's method. Blood urea level was significantly increased in the gentamicin treated group. The study showed lowered levels of urea and creatinine levels in resveratrol administered groups when compared with gentamicin administered rats, and the difference was statistically significant. It has been determined that resveratrol caused statistically significant decrease in lipid peroxidation and reduced the level of catalase. Histopathological examination showed that resveratrol prevented partly gentamicin induced tubular damage. The results histopathologically demonstrated that resveratrol has a protective effect against gentamicin induced nephrotoxicity, lipid peroxidation and cellular damage in rats.