Resveratrol reduces light and electron microscopic changes in acetaminophen-induced hepatotoxicity in rats: Role of iNOS expression.

INTRODUCTION: Hepatotoxicity is a major complication of acetaminophen (APAP), a widely used analgesic and antipyretic drug. Resveratrol (RSV) is a naturally occurring diphenol and it has anticancer, antioxidant, and anti-inflammatory properties. OBJECTIVES: In this study, the beneficial effects of RSV on APAP-induced hepatotoxicity was investigated in rats. MATERIALS AND METHODS: Group 1: Ethanol, Group 2: Saline, Group 3: RSV (10 mg/kg/ip), Group 4: APAP (1000 mg/kg/ip/single dose), Group 5: APAP+RSV (20 min after administration of APAP). The rats were sacrificed 24 h after administration of APAP. Light and electron microscopic changes were evaluated. Levels of malondialdehyde (MDA) and glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD) activities were determined in liver tissue. RESULTS: Rats of the ethanol, saline, and RSV groups did not present any histopathological alterations. In the APAP group, we observed vascular congestion, necrosis, inflammation, sinusoidal dilatation, and loss of glycogen content. In the APAP+RSV group, these changes were markedly reduced. iNOS immunostaining showed very weak positive stained hepatocytes the sections of control, saline, and RSV groups. However, in the APAP group, iNOS immunostaining was most evident in pericentral hepatocytes. In the same areas in APAP+RSV group, intensity of iNOS immunostaining decreased. A significant increase in MDA and decreases in GSH level, CAT, and SOD activity indicated that APAP-induced hepatotoxicity was mediated through oxidative stress. Significant beneficial changes were noted in tissue oxidative stress indicators in rats treated with RSV. CONCLUSION: These biochemical, histopathological, and ultrastructural findings revealed that RSV reduced the severity of APAP-induced alterations in liver.

Protective effect of hesperidin on oxidative and histological liver damage following carbon tetrachloride administration in Wistar rats.

INTRODUCTION: In the current study, the protective effect of hesperidin (HP) on carbon tetrachloride (CCl4)-induced hepatotoxicity in rats was investigated. MATERIAL AND METHODS: Twenty-eight rats were divided equally into four groups. The first group was kept as a control and given only vehicle. In the second, rats were orally administered 50 mg/kg/day HP for 10 days. Carbon tetrachloride was given in a single intraperitoneal injection at the dose of 2 ml/kg in the third group. In the fourth group, the rats were treated with equal doses of CCl4 and HP. RESULTS: It was found that CCl4 induced oxidative stress via a significant increase in the formation of thiobarbituric acid-reactive substances (TBARS) and caused a significant decline in the levels of glutathione (GSH), catalase (CAT) and superoxide dismutase (SOD) in rats. In contrast, HP blocked these toxic effects induced by CCl4, causing an increase in GSH, CAT and SOD levels and decreased formation of TBARS (p < 0.01). In addition, histopathological damage increased with CCl4 treatment. In contrast, HP treatment eliminated the effects of CCl4 and stimulated anti-apoptotic events, as characterized by reduced caspase-3 activation. CONCLUSIONS: The current study demonstrated that CCl4-induced hepatotoxicity can be prevented with HP treatment. Thus, co-administration of HP with CCl4 may be useful for attenuating the negative effects of CCl4 on the liver.

Anti-inflammatory Montelukast prevents toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin: Oxidative stress, histological alterations in liver, and serum cytokine levels.

This study aimed to investigate the potential beneficial effects of the montelukast (ML) on oxidative stress and histological alterations in liver tissues and cytokine levels in rats intoxicated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Rats were divided randomly into four equal groups (control, TCDD, ML, TCDD + ML). TCDD were administered by gavages dissolved in corn oil at the doses of 2 µg/kg/week, and ML was given intraperitoneally at the dose of 10 mg/kg/day. Oxidative status, histological alterations, and cytokine levels were analyzed on day 60. The results showed that although TCDD induced oxidative stress via significant increase in formation of thiobarbituric acid reactive substance, it caused a significant decline in glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD) levels in liver. Besides, TCDD led to significant histopathological damage in liver and serum cytokine levels alterations (increase in tumor necrosis factor α and interleukin 1ß levels). In contrast, ML treatment reversed oxidative effects of TCDD by increasing the levels of GSH, CAT, and SOD and decreasing the formation of TBARS. Also, it can normalize the levels of histological and cytokine alterations induced by TCDD. In conclusion, it was determined that TCDD exposure caused adverse effects on cytokine levels, histological alterations, and oxidative stress in rats. However, ML treatment partially eliminated toxic effects of TCDD. Thus, it was judged that coadministration of ML with TCDD may be useful to attenuate the negative effects of TCDD.

Histopathological, Ultrastructural and Apoptotic Changes in Diabetic Rat Placenta.

BACKGROUND: The exchange of substances between mother and fetus via the placenta plays a vital role during development. A number of developmental disorders in the fetus and placenta are observed during diabetic pregnancies. Diabetes, together with placental apoptosis, can lead to developmental and functional disorders. AIMS: Histological, ultrastructural and apoptotic changes were investigated in the placenta of streptozotocin (STZ) induced diabetic rats. STUDY DESIGN: Animal experimentation. METHODS: In this study, a total of 12 female Wistar Albino rats (control (n=6) and diabetic (n=6)) were used. Rats in the diabetic group, following the administration of a single dose of STZ, showed blood glucose levels higher than 200 mg/dL after 72 hours. When pregnancy was detected after the rats were bred, two pieces of placenta and the fetuses were collected on the 20(th) day of pregnancy by cesarean incision under ketamine/ xylazine anesthesia from in four rats from the control and diabetic groups. Placenta tissues were processed for light microscopy and transmission electron microscopy (TEM). Hematoxylin-eosin (HE) and periodic acid Schiff-diastase (PAS-D) staining for light microscopic and caspase-3 staining for immunohistochemical investigations were performed for each placenta. Electron microscopy was performed on thin sections contrasted with uranyl acetate and lead nitrate. RESULTS: Weight gain in the placenta and fetuses of diabetic rats and thinning of the decidual layer, thickening of the hemal membrane, apoptotic bodies, congestion in intervillous spaces, increased PAS-D staining in decidual cells and caspase-3 immunoreactivity were observed in the diabetic group. After the ultrastructural examination, the apoptotic appearance of the nuclei of trophoblastic cells, edema and intracytoplasmic vacuolization, glycogen accumulation, dilation of the endoplasmic reticulum and myelin figures were observed. In addition, capillary basement membrane thickening, capillary endothelial cells chromatin condensation in the nucleus and corrugation of the nucleus were found. CONCLUSION: Diabetes causes histomorphometric, ultrastructural and apoptotic changes in rat placenta.

Histological and biochemical effects of dexmedetomidine on liver during an inflammatory bowel disease.

Inflammation in the liver is an extraintestinal manifestation that is frequently seen during inflammatory bowel diseases (IBD). The authors investigated histopathologycal, ultrastructural and antioxidant effects of dexmedetomidine (Dex) on liver during trinitrobenzene sulfonic acid (TNBS)-induced inflammatory bowel disease. Thirty-two BALB/c mice were divided (n = 8) as follows: control; Dex (dexmedetomidine) (30 µg/kg) for 6 days; TNBS 150 µL, TNBS + ethanol (50% w/v) intrarectally; TNBS + Dex. The histopathological and ultrastructural changes were evaluated. The levels of malondialdehyde (MDA), activity of antioxidant enzymes (GPx and SOD) were measured in liver tissue. Induction of colitis induced histopathological and ultrastructural changes of damage in liver. Those changes were markedly reduced in the TNBS + Dex group and that reduction was even significant in comparison to the TNBS group. MDA levels were significantly higher in the TNBS group and dexmedetomidine significantly elevated SOD levels in the TNBS + Dex group. These results suggest that the administration of dexmedetomidine reduces the histopathological and ultrastructural damage and increases the defense capacity against oxidative damage on liver in this IBD mice model.

The protective effects of Prunus armeniaca L (apricot) against methotrexate-induced oxidative damage and apoptosis in rat kidney.

This study was conducted to evaluate a possible protective role of apricot in apoptotic cell death induced by methotrexate (MTX) and renal damage by different histological and biochemical parameters. Twenty-eight rats were divided into four groups, control, apricot, methotrexate, and apricot + methotrexate. Methotrexate induced renal failure, as shown by significant serum creatinine and urea elevation. Additionally, the results indicated that methotrexate significantly induced lipid peroxidation and reduced antioxidant activities in rats. In contrast, apricot significantly prevented toxic effects of methotrexate via increased catalase, superoxide dismutase, and glutathione levels but decreased formation of malondialdehyde. Also, it was determined that exposure to methotrexate leads to significant histological damage in kidney tissue such as glomerulosclerosis and apoptosis. On the other hand, these effects can be eliminated with apricot diet. These data indicate that apricot may be useful in preventing undesirable effects of MTX such as nephrotoxicity.

Prunus armeniaca L (apricot) protects rat testes from detrimental effects of low-dose x-rays.

Exposure to low x-ray doses damages the spermatozoa, mainly by late-onset (ie, after 3 months) oxidative stress. Antioxidants ameliorate oxidation and prevent tissue damage. Prunus armeniaca L (apricot), rich in carotenoids and vitamins, is a potent natural antioxidant. We hypothesized that an apricot-rich diet might ameliorate the detrimental effects of low-dose x-rays on testis tissue. A 20% apricot diet was composed isoenergetically to the regular rodent diet. The total phenolic content, reducing power, and antioxidant capacity of both diets were determined. Sprague-Dawley rats received apricot-rich diets before and after x-ray exposure. Regular diets were given to controls. Rats were exposed to 0.2 Gy x-rays at the eighth week and were euthanized at the 20th postexposure week. Testicular oxidative status was determined by tissue thiobarbituric acid-reactive substances, reduced glutathione, superoxide dismutase, and catalase activities. For histologic evaluation, qualitative and quantitative microscopic determinations were performed, and Leydig and Sertoli cell counts and Johnsen scores were measured. The control diet group had significant testicular oxidative stress and mild tissue deterioration. Leydig and Sertoli cell counts, tubule diameters, and Johnsen scores were significantly decreased in the exposure groups. Apricot-rich diet significantly ameliorated the oxidative status and prevented the damage in tubular histology. The protective effects were prominent when the diet was maintained throughout the time course and were partially protected when the diet was initiated after exposure. The natural antioxidant activity of apricot ameliorates the delayed detrimental effects of low-dose irradiation on testis tissue. The high total antioxidant capacity of the apricot deserves further investigation.

Protective effect of apricot (Prunus armeniaca L.) on hepatic steatosis and damage induced by carbon tetrachloride in Wistar rats.

The present study was planned to investigate the protective effect of 10 % and 20 % apricot-containing feed on carbon tetrachloride (CCl4)-induced hepatic steatosis and damage. Adult male Wistar rats (n 42) were divided into six groups of seven each, as follows: control group; CCl4 group; CCl4+10 % apricot group; CCl4+20 % apricot group; 10 % apricot group; 20 % apricot group. All apricot groups were fed with 10 % or 20 % apricot-containing feed for 5 months. CCl4 injections were applied to the CCl4 groups at the dose of 1 mg/kg for 3 d at the end of 5 months. In the CCl4 group, vacuolated hepatocytes and hepatic necrosis were seen, especially in the centrilobular area. Hepatocytes showed an oedematous cytoplasmic matrix, large lipid globules and degenerated organelles. The area of liver injury was found significantly decreased with apricot feeding. Malondialdehyde and total glutathione levels and catalase, superoxide dismutase and glutathione peroxidase activities were significantly changed in the CCl4 group and indicated increased oxidative stress. Apricot feeding decreased this oxidative stress and ameliorated histological damage. We concluded that apricot feeding had beneficial effects on CCl4-induced liver steatosis and damage probably due to its antioxidant nutrient (beta-carotene and vitamin) contents and high radical-scavenging capacity. Dietary intake of apricot can reduce the risk of liver steatosis and damage caused by free radicals.

Apricot ameliorates alcohol induced testicular damage in rat model.

In this study, we intended to determine the possible preventive effects of dietary apricot on oxidative stress due to ethanol usage in rat testes. The animals were divided into six groups as follows: Group 1 was control. Group 2 received ethanol. Group 3 were fed with apricot diet for 3 months. Group 4 were fed with apricot diet for 6 months. Group 5 received ethanol and apricot diet for 3 months. Group 6 were fed apricot diet for 3 months, and then ethanol+apricot diet for 3 months. Following sacrification, the testes were treated for morphological (tubular and germ cell histology, Sertoli and Leydig cell counts) and biochemical (superoxide dismutase, glutathion peroxidase, catalase, malondialdehyde) analyses. In Group 2, severe histopathological changes in seminiferous tubules and germ cells were determined as well as tubular degeneration and atrophy. Sertoli and Leydig cell counts in the interstitial tissue were decreased. Biochemical parameters revealed tissue oxidative stress. Similar alterations existed in Group 5, although to a lesser extent. In Groups 1, 3 and 4, no histopathological alterations were noted. Results of Group 6 were similar to the controls. Apricot rich diet may have a preventive role on histopathological changes caused by alcohol in rat testes.

The effect of resveratrol in tracheal tissue of rats exposed to cigarette smoke.

OBJECTIVE: The aim of this study was to evaluate the effect of resveratrol on the tracheal tissue of rats exposed to cigarette smoke. MATERIALS AND METHODS: 40 adult Wistar albino rats were divided into four groups for an experiment of 6 weeks. Animals in group 1 were controls (n = 10). Rats in group 2 were exposed to cigarette smoke only, and rats in group 3 received daily intraperitoneal injections of resveratrol (10 mg/kg/d). Animals in group 4 were exposed to both cigarette smoke and intraperitoneal injections of resveratrol. Rats of all groups were sacrificed using cervical dislocation. The tracheas were removed and embedded in paraffin blocks. Sections of 4-5 mum thickness were prepared from the blocks. These sections were stained with hematoxylin and eosin, periodic acid-Schiff, and Alcian blue and viewed with a Leica DFC 280 light microscope. RESULTS: Tracheal sections showed that, in group 2 (cigarette smoke group), there was desquamation of epithelial cells into the tracheal lumen, loss of cilia in the epithelial layer, an increase of goblet cells, activation of serous glands at the submucosa, and cell infiltration. In group 4 (cigarette smoke + resveratrol group), all these findings also existed but only a few sections were affected. It was observed that cigarette smoking caused morphological changes such as epithelial degeneration in the upper airway. These morphological changes were correlated with the amount of toxic substances in the cigarette smoke. CONCLUSION: We found that resveratrol had a preventive role in the histopathological changes caused by cigarette smoking in the rat trachea.

Beneficial effects of apricot-feeding on myocardial ischemia-reperfusion injury in rats.

The present study was undertaken to evaluate the cardio-protective potential of apricot-feeding in the ischemia-reperfusion (I/R) model of rats in vivo. Rats were divided into three groups of 12 rats each. Group 1 was fed with a standard rat chow, groups 2 and 3 were fed with a standard rat chow supplemented with 10% or 20% dried apricot during 3 months before the beginning of I/R studies. To produce I/R, the left main coronary artery was occluded for 30 min, followed by 120 min reperfusion, in anesthetized rats. Infarct sizes were found significantly decreased in 10% (55.0 +/- 4.3%) and 20% (57.0 +/- 2.9%) apricot-fed groups compared to control group (68.7 +/- 2.0%). Light and electron microscopic evaluations of hearts also demonstrated similar beneficial effects on I/R injury in apricot-fed both groups. Total phenolic contents, DPPH radical scavenging and ferric-reducing power as in vitro antioxidant capacities of rat chows were significantly increased after supplementation with apricot for each ratio. Cu, Zn Superoxide dismutase (Cu, Zn SOD) and catalase (CAT) activities were increased, and lipid peroxidation was decreased significantly in the hearts of 20% apricot-fed group after I/R. In conclusion, we clearly demonstrated in vivo cardio-protective activity of apricot-feeding related to its antioxidant phenolic contents in rats subjected to myocardial I/R.

The beneficial effects of pentoxifylline on caerulein-induced acute pancreatitis in rats.

In this study we aimed to investigate the effect of pentoxifylline on caerulein-induced acute pancreatitis (AP) by detecting oxidative stress markers and performing histopathological examination. Twenty-one adult female Sprague-Dawley rats were divided into three groups as follows: control, caerulein, and caerulein + pentoxifylline groups. Pancreatic tissues of rats from all groups were removed for light and electron microscopic examination and determination of oxidative stress markers. Pancreatic oxidative stress markers were evaluated by the measurements of malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and total glutathione (GSH). Serum amylase and lipase levels were determined spectrophotometrically. The pancreatic damage score was significantly increased (P < 0.005) in the caerulein group, whereas it was decreased (P < 0.05) in the caerulein+ with pentoxifylline group. MDA levels, CAT, SOD, GPx, and GSH activities were significantly altered (P < 0.05, P < 0.005) in the caerulein group and indicated increased oxidative stress. Oxidative stress markers were normalized with pentoxifylline administration. Caerulein administration resulted in significant increase (P < 0.05) in amylase and lipase levels; pentoxifylline reduced the levels of these enzymes. Pentoxifylline is potentially capable of limiting pancreatic damage produced during AP by restoring the fine structure of acinar cells and tissue antioxidant enzyme activities. We concluded that pentoxifylline may have beneficial effects in the treatment of caerulein-induced AP.

Antiapoptotic and antioxidant effects of beta-carotene against methotrexate-induced testicular injury.

OBJECTIVE: To investigate the effect of beta-carotene against testicular injury induced by methotrexate (MTX). DESIGN: Experimental study. SETTING: Animal and histology laboratory at Inonu University. ANIMAL(S): Twenty-eight Wistar male rats. INTERVENTION(S): Twenty-eight rats were separated into four groups: control, beta-carotene, MTX, and beta-carotene + MTX. At the end of the treatment, the animals were killed, and tissue samples were examined via histologic and biochemical methods. MAIN OUTCOME MEASURE(S): In each group, 100 tubules were classified as intact, sloughing, atrophic, and degenerated. Caspase-3, a universal effector of apoptosis, was evaluated according to staining in place of coloring as weak, mild, and strong. RESULT(S): In the MTX group, 58.5 + 3.7% of tubules were sloughing, 10.8 + 2.1% of tubules were atrophic, and 2.0 + 0.6% of tubules were degenerative. In the beta-carotene + MTX group, the affected tubule number was statistically significantly lower than in the MTX group. The distribution of caspase-3 in the MTX group showed a statistically significant increase, but it decreased in the beta-carotene + MTX group. The enzyme activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GP-x) and the level of malondialdehyde (MDA) increased and decreased in parallel. CONCLUSION(S): Our results indicate that beta-carotene may be useful in decreasing the side effects of chemotherapy, including apoptotic cell death.

Potent protective effect of apricot and beta-carotene on methotrexate-induced intestinal oxidative damage in rats.

Several studies have well confirmed the contribution of oxidative stress in the pathogenesis of methotrexate (MTX)-induced damage in the small intestine. Many agents have been tried experimentally to reduce or inhibit the oxidative stress. To our knowledge, there is no study about apricot consumption on the MTX-induced damage in the small intestine. The aim of this study was to determine the possible protective effects of apricot and beta-carotene on MTX-induced intestinal damage in rats. The rats were randomly divided into seven groups as follows; I-control group; II-apricot group; III-beta-carotene group; IV-MTX group; V-apricot+MTX group; VI-beta-carotene+MTX group and VII-apricot+beta-carotene+MTX group. In the MTX group; fusion and shortening in the villus, epithelial desquamation, crypt loss, inflammatory cell infiltration in the lamina propria, goblet cell depletion and microvillar damage were observed in the small intestine. Parallel to histological results, malondialdehyde (MDA) content and myeloperoxidase (MPO) activity were found to be increased, whereas superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GP-x) activities and glutathione (GSH) content were decreased in the MTX group. However, single or combined application of apricot and beta-carotene ameliorated all of these hazardous effects in antioxidant system in MTX-treated groups. In conclusion, our results demonstrate that apricot and/or beta-carotene treatment may protect the impairment of oxidative stress and ameliorate MTX-induced intestine damage at biochemical and histological levels.

Oral L-arginine protects against cyclosporine-induced hepatotoxicity in rats.

Cyclosporine A (CyA) leads to liver injury, probably by causing the production of free radicals and resulting in nitric oxide (NO) deficiency. We evaluated CyA-mediated liver damage histopathologically to determine the possible beneficial effects of L-arginine (L-Arg). In this study, 7 groups of Sprague-Dawley rats; (1) Control group; (2) 0.9% NaCl group; (3) CyA group: 7.5mg/kg/day; (4) L-Arg group: 2g/lt/day; (5) l-NAME (N-nitro-L-arginine methyl ester) group: 5mg/100ml/day; (6) CyA+L-Arg group: L-Arg (2g/lt/day)+CyA (7.5mg/kg/day); and (7) CyA+L-NAME group: CyA (7.5mg/kg/day)+L-NAME (5mg/100ml/day) were included. At the end of the treatments, animals were killed and hepatic tissues were treated for morphological (hematoxylin and eosin) and biochemical (NO and malondialdehyde, MDA) analyses, and serum was processed for biochemical (alanine transaminase (ALT), aspartate transaminase (AST), bilirubin, alkaline phosphatase (ALP) and total protein) study. The results indicated that CyA-induced hepatotoxicity was characterized by sinusoidal dilatation, hepatocellular vacuolization, neutrophilic infiltration and hepatocellular necrosis. These findings were less pronounced in the CyA+L-Arg group than CyA alone group. L-NAME group showed moderate changes. The CyA+L-NAME (Group 7) had more severe changes. We found changes in tissue NO and MDA levels. We think that the tissue damage caused by CyA is mild and reversible at the period when biochemical parameters are just starting to become abnormal and that L-Arg may have a protective effect against CyA damage on liver.