Antioxidant Enzyme Activities In Tissues Research Articles

Changes of Oxidative Stress, Glutathione, and Its Dependent Antioxidant Enzyme Activities in Patients with Hepatocellular Carcinoma before and after Tumor Resection.

The changes in and relationship between oxidative stress and the glutathione (GSH) antioxidant system in the plasma and tissues of patients with hepatocellular carcinoma (HCC) before and after tumor resection have not been clearly determined. We investigated the changes in oxidative stress, GSH status and its dependent antioxidant enzyme activities in HCC patients before and after tumor resection, and to determine the association of oxidative stress with GSH and its dependent antioxidant enzyme activities in plasma and tissues. This study employed a cross-sectional design. Forty-four men and 16 women with HCC were recruited. Fasting blood was drawn on the day before the tumor resection and one month after the tumor resection. HCC tissue and adjacent normal liver tissue were obtained at the time of surgical resection. Patients had significantly increased plasma malondialdehyde (MDA) and oxidized-low density lipoprotein levels but decreased GSH and oxidized GSH levels before tumor resection compared with the corresponding post-resection values. GSH and trolox equivalent antioxidant capacity (TEAC) levels and activities of GSH peroxidase were significantly increased while MDA level was significantly lower in HCC tissue when compared with the adjacent normal tissue. The pre-resection plasma MDA level was significantly correlated with pre-resection plasma GSH concentration, and MDA level in HCC and adjacent normal tissues. Pre-resection plasma GSH concentration was significantly correlated with GSH and TEAC level in HCC tissue. HCC patients had increased oxidative stress, decreased GSH, and lower dependent antioxidant capacities before tumor resection. However, hepatocellular tumor had increased GSH and TEAC levels as well as GSH peroxidase activities which might protect itself against increased oxidative stress.

The Propolis Effect on Chlorpyrifos Induced Thyroid Toxicity in Male Albino Rats

Chlorpyrifos (CPF) is a chlorinated organophosphate insecticide that is used widely in the world and Egypt. The aim of present work was to study the possible protective role of Propolis on thyroid gland of male rats after chronic exposure of chlorpyrifos. For this purpose, Fifty adult male albino rats were randomized into 5 groups: I, II (Control), III (received Propolis dissolved in 0.5 ml corn oil, 50 mg/kg b.w./day), IV (received CPF dissolved in 0.5 ml corn oil 6.75 mg/kg b.w./ day) and V (received CPF and Propolis at the same previously mentioned doses). Rats were orally treated by gavage for 12 weeks. We found that Chlorpyrifos induced damaging effects in thyroid tissue architecture, thickened collagen fibers between the follicles and decreased periodic acid schiff (PAS) reaction in the colloids. Immunohistochemically, there was weak thyroglobulin (TGB) expression. Besides, it significantly decreased the serum levels of Tri-iodothyronin (T3), Tetraiodothyronin (T4) and Thyroid stimulating hormone (TSH). It depressed reduced glutathione (GSH) content and antioxidant enzyme activities in thyroid tissues with respect to control groups. Furthermore, CPF increased thyroid oxidative stress as manifested by elevated malondialdehyde (MDA) levels. On the other hand, the concurrent administration of Propolis with CPF showed significant improvement in previous changes. Our findings showed that the concurrent oral administration of Propolis with CPF improved the CPF induced oxidative damaging effects in thyroid gland and the antioxidative defense in the rats.

Selenium Nanoparticles Attenuate Oxidative Stress and Testicular Damage in Streptozotocin-Induced Diabetic Rats.

We investigated the protective and antioxidative effects of selenium nanoparticles (SeNPs) in streptozotocin STZ-induced diabetic rats. STZ-diabetic rats were exposed daily to treatments with SeNPs and/or insulin and then the effect of these treatments on the parameters correlated to oxidative damage of the rat testes were assessed. Biochemical analysis revealed that SeNPs are able to ameliorate the reduction in the serum testosterone caused by STZ-induced diabetes. Furthermore, SeNPs could significantly decrease testicular tissue oxidative stress markers, namely lipid peroxidation and nitric oxide. In contrast, treatment of the STZ-diabetic rats with SeNPs increased the glutathione content and antioxidant enzyme activities in testicular tissues. Moreover, microscopic analysis proved that SeNPs are able to prevent histological damage in the testes of STZ-diabetic rats. Molecular analysis revealed that the mRNA level of Bcl-2 (B-cell lymphoma 2) is significantly upregulated. On the contrary, the mRNA level of Bax (Bcl-2 Associated X Protein) was significantly downregulated. Furthermore, treatment of STZ-diabetic rats with SeNPs led to an elevation in the expression of PCNA (Proliferating Cell Nuclear Antigen Gene). Interestingly, the insulin treatment also exhibited a significant improvement in the testicular function in STZ-diabetic rats. Collectively, our results demonstrated the possible effects of SeNPs in attenuating diabetes-induced oxidative damage, in particular in testicular tissue.

Effects of copper oxide nanoparticles on antioxidant enzyme activities in gill and liver tissues of Oreochromis niloticus

Effects of copper oxide nanoparticles on antioxidant enzyme activities in gill and liver tissues of Oreochromis niloticus

A comparative study on the antioxidant effects of hesperidin and ellagic acid against skeletal muscle ischemia/reperfusion injury

The antioxidant effects of ellagic acid (EA) and hesperidin (HES) against skeletal muscle ischemia/reperfusion injury (I/R) were performed. Hindlimb ischemia has been induced by tourniquet occlusion for 2 h on left hindlimb. At the end of ischemia, the tourniquate has been removed and initiated reperfusion for 2 h. EA (100 mg/kg) has been applied orally before ischemia/reperfusion in the EA + I/R group. HES (100 mg/kg) has been given orally in the HES + I/R group. The left gastrocnemius muscle has been harvested and stored immediately at −80 °C until assessed for the levels of MDA and antioxidant enzymes activities. MDA level has statistically increased in I/R group (p < 0.05) compared to other groups. The muscle tissue antioxidant enzymes activities were lower than the other groups in the I/R group (p < 0.05). EA and HES treatments significantly reversed the damage level in I/R, also activity of tissue SOD increased in the EA + I/R and HES + I/R groups.

Lycopene ameliorates atrazine-induced oxidative damage in adrenal cortex of male rats by activation of the Nrf2/HO-1 pathway.

Atrazine (ATZ) is one of the most commonly used herbicides contaminating plants, soil and water resources. Several strategies have been used to counteract ATZ toxicity. Here, we tested the hypothesis that lycopene could ameliorate ATZ-induced toxicity in the adrenal cortex. For this purpose, 35 adult male albino rats were randomized into five equal groups: untreated control, vehicle control (received 0.5mL corn oil/day), lycopene (treated with lycopene dissolved in 0.5mL corn oil, 10mg/kg b.w./day), ATZ (received ATZ dissolved in 0.5mL corn oil 300mg/kg b.w./day), and ATZ + lycopene (treated with ATZ and lycopene at the same previously mentioned doses). All treatments were given by oral gavage for 4weeks. We found that ATZ exposure significantly increased relative adrenal weight, plasma ACTH levels, and adrenal oxidative stress as manifested by elevated malondialdehyde levels, decreased reduced glutathione content and depressed antioxidant enzyme activities in adrenal cortex tissues with respect to control groups. Furthermore, the transcription of adrenal cortex nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), nuclear factor kappa B, and caspase-3 genes was increased significantly compared with the control groups. This was accompanied with DNA fragmentation and structural and ultrastructural changes in zona glomerulosa and zona fasiculata of the adrenal cortex. Notably, all these changes were partially ameliorated in rats treated concomitantly with ATZ and lycopene. Our results showed that lycopene exerts protective effects against ATZ-induced toxicity in rat adrenal cortex. These effects may be attributed to the antioxidative property of lycopene and its ability to activate the Nrf2/HO-1 pathway.

Toxicity of OTC to Ipomoea aquatica Forsk. and to microorganisms in a long-term sewage-irrigated farmland soil.

Water spinach (Ipomoea aquatic Forsk.) was selected to investigate the effects of oxytetracycline (OTC) on the toxicity of soil contaminated by long-term sewage irrigation. After acute toxicity test in petri dish at nine different OTC-spiked levels for 48h, the germination rate was found to be generally inhibited in all treatments treated with OTC but the root elongation and activities of several antioxidant enzymes, superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) were either forward or backward stimulated to varying extent. During a 60-day sub-chronic toxicity test by means of a pot experiment, activities of SOD, POD and CAT in both the leaf and root tissue at 25mg OTC per kg soil (dry weight) and in root tissue at 1mg OTC per kg soil (dry weight) were significantly different than those in other treatments, which also indicated the higher sensitivity of the root. The foliar photosynthetic rate, stomatal conductance and transpiration rate were all gradually inhibited in spite of elevated water use efficiency under the pressure of the different OTC concentrations, which were highly significant different at 10mg OTC per kg soil (dry weight). Indices of soil microbial diversity at 4mg OTCkg(-1) soil were significantly different from those of the control, indicating the potential adverse effects of OTC to soil microorganisms. The results suggest that the introduction of OTC could damage both plants and soil microorganisms, and during sub-chronic incubation, the sensitivity of different indices generally followed the order of root tissue antioxidant enzyme activities, soil microbial diversity indices, leaf photosynthesis-related index and leaf tissue enzyme antioxidant activities. In addition, the application of livestock and poultry manure containing pollutants like OTC in farmland soil, especially if the soil has been contaminated before, should be taken more seriously in the context of the current pursuit of increased agricultural production.

Interspecific and environment-induced variation in hypoxia tolerance in sunfish

Hypoxia tolerance is a plastic trait, and can vary between species. We compared hypoxia tolerance (hypoxic loss of equilibrium, LOE, and critical O2 tension, Pcrit) and traits that dictate O2 transport and metabolism in pumpkinseed (Lepomis gibbosus), bluegill (L. macrochirus), and the naturally occurring hybrid in different acclimation environments (wild versus lab-acclimated fish) and at different temperatures. Wild fish generally had lower Pcrit and lower PO2 at LOE in progressive hypoxia than lab-acclimated fish, but time to LOE in sustained hypoxia (PO2 of 2kPa) did not vary between environments. Wild fish also had greater gill surface area and higher haematocrit, suggesting that increased O2 transport capacity underlies the environmental variation in Pcrit. Metabolic (lactate dehydrogenase, LDH; pyruvate kinase, PK; citrate synthase; cytochrome c oxidase) and antioxidant (catalase and superoxide dismutase) enzyme activities varied appreciably between environments. Wild fish had higher protein contents across tissues and higher activities of LDH in heart, PK in brain, and catalase in brain, liver, and skeletal muscle. Otherwise, wild fish had lower activities for most enzymes. Warming temperature from 15 to 25°C increased O2 consumption rate, Pcrit, PO2 at LOE, and haemoglobin-O2 affinity, and decreased time to LOE, but pumpkinseed had ≥2-fold longer time to LOE than bluegill and hybrids across this temperature range. This was associated with higher LDH activities in the heart and muscle, and lower or similar antioxidant enzyme activities in several tissues. However, the greater hypoxia tolerance of pumpkinseed collapsed at 28°C, demonstrating that the interactive effects of hypoxia and warming temperature can differ between species. Overall, distinct mechanisms appear to underpin interspecific and environment-induced variation in hypoxia tolerance in sunfish.

Responses of metabolic and antioxidant enzymatic activities in gill, liver and plasma of Catla catla during methyl parathion exposure

BackgroundUse of pesticides in agricultural fields has a series of toxicological and environmental problems. Methyl parathion (MP), an organophosphorus (OP) insecticide is a widely used pesticide and is highly toxic to non-target organisms. Fish has been used as indicator species for monitoring of pollution in the aquatic environment. Catla catla an Indian major carp is an edible fish and is highly sensitive to slight stress. Recently, fish biomarkers are widely used to determine the internal and external health status caused by chemicals. ResultsC. catla were exposed to acute (0.09ppm) and sublethal (0.009ppm) concentrations of MP to determine the alterations in antioxidant and metabolic enzyme activities in blood plasma and tissues (gill and liver). Intoxication with MP resulted in induction of oxidative stress which implies that fish utilizes enzymatic mechanisms to tolerate the effects caused by generated ROS due to MP accumulation. Significant alterations in GOT and GPT activity in plasma and tissues during acute as well as sublethal exposure might have resulted from the organal damage. The significant increase of LDH activity indicates severe cellular damage in organ/tissues of MP treated fish. ConclusionThe results of the present investigation suggest that gill is the most sensitive organ to MP toxicity. The alterations of the enzymatic parameters can be effectively used as potential biomarkers for monitoring of the organophosphorus pesticides in aquatic environment. Further, MP should be used with caution in order to protect natural waters and aquatic organisms.

English

The present study aimed at evaluating the effect of&nbsp;Tribulus terrestris&nbsp;on different parameters of oxidative stress and enzymatic/non-enzymatic antioxidant as well as the number, viability and abnormalities of sperm in testis tissues of male rats after induction of diabetes. The animals were divided into six groups; group I (control) was administered vehicle only, group II was treated with metformin (MET) and those in group III were given&nbsp;T. terrestris&nbsp;plant extract (TT extract). Group IV acted as positive diabetic control, group V and VI were diabetic animals treated with MET and TT-extract, respectively. The treatments were continued for 5 days/week for 60 days. Various oxidative stress parameters&nbsp;such as lipid peroxidation and activity of antioxidant enzymes were used to confirm the per-oxidant state of animals as an effect of different treatments. T. terrestris was noticed to reduce the oxidative stress levels, and restore antioxidant enzyme activity in testis tissues as well as to improve the lipid profile content in serum. Histological analysis showed that&nbsp;T. terrestris&nbsp;treatment decreased testis tubular damage, and restored it to normal morphology. It can be concluded that TT extract as compared to metformin has potential effect against spermatotoxic and testicular toxicity and it can improve redox state in diabetic male rats. Key words: Tribulus terrestris, oxidative/antioxidant, fertility indices, diabetes.

Hepatoprotective activity of total iridoid glycosides isolated from Paederia scandens (lour.) Merr. var. tomentosa

Ethnopharmacological relevanceCurrently, human liver is susceptible to injury caused by alcohol and virus infiltration, resulting in hepatitis, cirrhosis, and even hepatocellular carcinoma. Paederia scandens (Lour.) Merr. var. tomentosa (Rubiaceae) has been used as traditional medicine in Asian countries to treat jaundice, dysentery, and abdominal mass. Furthermore, the abundance of iridoid glycosides in Paederia species indicates their notable hepatoprotective potential. Materials and methodsTotal iridoid glycosides (TG) was prepared, and constituents of TG were analyzed by HPLC. TG and silymarin (positive) were orally administered for 15 days. Then, acute liver injury rats was induced by intraperitoneally injection (i.p.) of 10% CCl4 (0.12%, v/v, dissolved in olive oil, 10mL/kg, body weight). Rats were sacrificed at 16h after CCl4 injection. Liver tissues and blood were collected. Serum samples were prepared to determine the activities of alanine transaminase (ALT) and aspartate transaminase (AST), whereas liver tissue sections were prepared for the purpose of examining possible liver histopathological changes. In addition, antioxidant enzyme activities in liver tissues were also evaluated. ResultsOur results demonstrated that TG significantly decreased the levels of AST and ALT, compared with those in control rats. In addition, pre-treatment of the rats with TG clearly alleviated their liver tissue injuries. What’s more, the activities of GSH, GAT and SOD in the groups of TG-treated rats were significantly increased compared with those of rats in the control group, whereas the levels of MDA were decreased. ConclusionsOur present research indicated that TG possessed notable hepatoprotective activity via decreasing oxidative stress level in liver tissues.

Chard (Beta vulgaris var. cicla) extract improved hyperglycemia-induced oxidative stress and surfactant-associated protein alterations in rat lungs

Context: Chard is used as an antidiabetic agent by the diabetic patients in Turkey.Objective: The effect of chard extract [Beta vulgaris L. var. cicla (Chenopodiaceae)] on the antioxidant system and the expression of surfactant-associated proteins (SP) in the lungs of hyperglycemic rats were examined.Materials and methods: Hyperglycemia was induced by a single dose of streptozotocin (60 mg/kg) provided intraperitoneally. Fourteen days after the rats were rendered hyperglycemic, the chard (2 g/kg/d), insulin (6 U/kg/d), and chard plus insulin (as mentioned above) were administered to rats for 45 d. On day 60, rats’ lungs were removed. Oxidative stress parameters and SP expression were assayed.Results: The lungs of hyperglycemic rats were characterized by the induced lipid and protein oxidation, elevated myeloperoxidase and xanthine oxidase activities, decreased glutathione levels, and reduced tissue factor and antioxidant enzymes activities (catalase, superoxide dismutase, glutathione peroxidase, and glutathione-S-transferase). Chard treatment alone and chard treatment combined with insulin were capable of achieving a regression of pulmonary oxidative stress, by inhibiting lipid and protein oxidation, and restoring the antioxidant system of hyperglycemic rats. SP-A expressions were significantly unchanged in all groups, whereas pro-SP-C and SP-D expressions were reduced in hyperglycemic rats. Pro-SP-C and SP-D levels were increased by chard and insulin administrations alone and combined in hyperglycemic rats.Discussion and conclusion: All treatments have a positive effect on the surfactant and antioxidant systems of the lungs of hyperglycemic rats. The best therapeutic effect was provided by treatment with chard extract alone in the compensation of hyperglycemic symptoms.

125 Toxic Effects of Chronic Sub-Lethal Cu 2+ , Pb 2+ and Cd 2+ on Antioxidant Enzyme Activities in Various Tissues of the Blood Cockle, Anadara granosa

125 Toxic Effects of Chronic Sub-Lethal Cu 2+ , Pb 2+ and Cd 2+ on Antioxidant Enzyme Activities in Various Tissues of the Blood Cockle, Anadara granosa

Sub-chronic Administration of Methanolic Whole Fruit Extract of Lagenaria breviflora (Benth.) Roberty Induces Mild Toxicity in Rats.

Background:The effect of the methanolic whole fruit extract from Lagenaria breviflora on vital organs and antioxidant enzymes was investigated in this study.Materials and Methods:L. breviflora (250, 500 and 1000 mg/kg/b.w.t./day/rat) was fed orally with the cannula to male albino rats for 28 days. At the end of the treatment, the rats were sacrificed and the effect of the extract on histology of the liver, heart, lipid peroxidation, tissue and serum antioxidant enzymes (superoxide dismutase, catalase, glutathione-s-transferase, glutathione peroxidase) activities, glutathione, myocardial marker enzymes (creatine kinase [CK], lactate dehydrogenase [LDH], alanine transaminase [ALT], and aspartate transaminase [AST]) in serum, and heart homogenate were assessed.Results:The extract demonstrated mild organ doses dependent (500 and 1000 mg/kg) pathological alterations in the architectural section of the liver and heart. At 250 mg/kg/b.w.t., the extract caused a significant (P < 0.05) increase in the level of thiobarbituric reacting acids substance and antioxidant enzyme activities, but causes (P < 0.05) decrease in serum and tissue antioxidant capacity at 500 and 1000 mg/kg/b.w.t., respectively. Also on these two doses, a significant (P < 0.05) increase in serum activity of CK, LDH, ALT, and AST and concomitantly decrease (P < 0.05) in heart homogenate were also observed.Conclusion:The results suggested that the Fruit of L. breviflora may contain phytotoxic Substances(s) which may be hepatotoxic, cardiotoxic or able to induce oxidative stress at high concentration. Hence, the consumption of the plant should be taken with caution.SUMMARY Methanolic whole fruit extract from Lagenaria breviflora demonstrate dose dependent mild toxicity on vital organs (Heart and liver) and anti-oxidant enzymes. The fruit of Lagenaria breviflora may contain Phyto-toxic substance (s) which may be hepatotoxic, Cardio-toxic or able to induce oxidative stress at high concentration. Hence, the consumption of the plant should be taken with caution.

Anti-fatigue activities of polysaccharides extracted from Hericium erinaceus.

Hericium erinaceus (HEP) is a notable medicinal fungus grown in China and other oriental countries. Polysaccharides from HEP have recently attracted considerable attention due to their numerous physiological activities. The objective of this study was to evaluate the anti-fatigue activity of HEP in a mouse model. After one week of acclimation, mice were randomly divided into four groups: a control group, a low-dose HEP-treated group, a moderate-dose HEP-treated group, and a high-dose HEP-treated group. The treated groups received HEP (50, 100 and 200 mg/kg, ig), while the control group received saline solution. Following treatment for 28 days, the mice performed a forced swimming test until they were exhausted, then the exhaustive swimming time was recorded along with certain biochemical parameters related to fatigue, including blood lactic acid (BLA), serum urea nitrogen (SUN), tissue glycogen, superoxide dismutase (SOD), glutathione peroxidase (GPx) and malondialdehyde (MDA). These results suggested that HEP has significant anti-fatigue activity by decreasing BLA, SUN and MDA content, as well as increasing tissue glycogen content and antioxidant enzyme activity. Based on these results, this study provided theoretical support for the application of HEP in the field of sports nutrition.

Chromium-induced nephrotoxicity and ameliorative effect of carvedilol in rats: Involvement of oxidative stress, apoptosis and inflammation

Nephrotoxicity is a major adverse effect of chromium poisoning. In the present study, we investigated the potential renoprotective effect and underlying mechanisms of carvedilol, a non-specific β-adrenergic blocker using rat model of potassium dichromate-induced nephrotoxicity. Rats were pretreated with carvedilol (10mg/kg) for 21days. A single subcutaneous injection of potassium dichromate (15mg/kg, s.c.) resulted in a significant increase in the levels of blood urea nitrogen and serum creatinine, markers related to oxidative stress, nitrosative stress, apoptosis and inflammation accompanied with histopathological changes in kidney tissues. Exploration of the underlying renoprotective mechanisms of carvedilol revealed that carvedilol attenuated nuclear translocation and DNA binding activity of NF-κB (p65) in kidney tissues. The serum levels of TNF-α and the renal expression of iNOS and tissue nitrites were significantly decreased in carvedilol plus potassium dichromate administered rats. Carvedilol pretreatment significantly attenuated the potassium dichromate-induced DNA damage, decreased the p53, Bax and cleaved caspase-3 expression and increased the Bcl-2 expression. Moreover, pretreatment with carvedilol significantly restored the renal tissue antioxidant and mitochondrial respiratory enzyme activities and decreased the elevated lipid peroxidation biomarkers to normal. These results were further supported and confirmed by histopathological findings. In conclusion, the findings of the present study demonstrated that carvedilol is an effective chemoprotectant against potassium dichromate-induced nephrotoxicity in rats.

Antioxidant Effect of Ardeh and Honey Combination on Ethanol-induced Oxidative stress in Liver and Kidney of Rats

Background: The pathogenesis of ethanol in the liver and kidney is associated with an increase in free radicals and oxidative stress that leads to structural and functional abnormalities in these vital organs. Methods: Forty-eight male wistar rats were placed in eight groups and were treated as follows: control group (normal saline), group of ethanol (4 g/ kg), three doses of Ardeh and honey combination (1, 2 and 5 g/ kg body weight), and the three groups received three doses of Ardeh and honey combination with ethanol (the same three doses of combinations along with 4 g/ kg ethanol). All treatments were performed once daily for 60 consecutive days with method of stomach gavages. Serum, liver and kidney tissue samples were obtained in order to assess serum components, tissue antioxidant enzyme activities, and the level of thiobarbituric acid reactive substances (TBARS). Results: Hepatic superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzymes in the ethanol group significantly decreased compared with the control group, while the Ardeh and honey combination (5 g) could only significantly increased glutathione peroxidase activity. Renal GPx activity in ethanol consumption significantly increased compared to controls. GPx activity in Ardeh and honey combination and alcohol (5 g, 4 g) were significantly reduced compared to ethanol group. In the present study, the amount of TBARS which represents the rate of lipid peroxidation, in liver of ethanol group compared with the control group showed a significant increase (P<0.05). Conclusion: Ardeh and honey combination as a pre-treatment, protect liver and kidney against oxidative damage induced by ethanol.

Progesterone and cilostazol protect mice pancreatic islets from oxidative stress induced by hydrogen peroxide.

Reactive oxygen species and oxidative stress impair β-cell function and reduce insulin secretion. It has been shown that progesterone and cilostazol possess antioxidant properties. The present study was aimed to investigate in-vitro pretreatment effect of progesterone and cilostazol on insulin secretion as well as their protective effects against hydrogen peroxide-induced oxidative stress in pancreatic isolated islets from mouse. Pancreatic islets were isolated from 84 male NMRI mice (25-30 g) by collagenase digestion method and pretreated for 48 h with cilostazol (10 μM), progesterone (0.5 μM) and glibenclamide (10 μM) in culture medium. Then islets were exposed to hydrogen peroxide (H2O2. 500 μM) for 2 h. Next, culture mediums containing glucose concentration of 2.8 mM or 16.7 mM were added to them and incubated in this status for 1 h. At the end, the rate of insulin output from islets, lipid peroxidation and antioxidant enzymes activities in islet tissues were assayed. Exposure of islets to H2O2, resulted in a significant decrease in insulin secretion, superoxide dismutase and catalase activities (P < 0.001). Also islets malondialdehyde levels were increased by H2O2, after addition of 2.8 mM (P < 0.05) and 16.7 mM (P < 0.001) glucose. 48 h pretreatment of islets with cilostazol and progesterone, significantly reverted back this changes (P < 0.05). Results of present study showed that cilostazol and progesterone protect mice pancreatic islets against H2O2-induced oxidative stress. At the end, our results suggested that protective effects of progesterone and cilostazol are mediated by augmentation the antioxidant defence system of islets.

Antioxidant potential of zinc–flavonol complex studied in streptozotocin‐diabetic rats (锌黄酮醇复合物在链脲霉素‐糖尿病大鼠中的抗氧化作用)

Diabetic oxidative stress coexists with a reduction in the antioxidant status, which can further increase the deleterious effects of free radicals. Zinc is an essential trace element with significant antidiabetic activity. However, the acceptance of zinc compounds as promising therapeutic antidiabetic agents has been slowed due to concerns regarding chronic toxicity. Recently, we have designed, synthesized and characterized a novel zinc-flavonol complex and evaluated its antidiabetic efficacy in streptozotocin (STZ)-diabetic rats. The aim of the present study was to evaluate the role of the zinc-flavonol complex in the antioxidant status of diabetic rats. Diabetes was induced in rats by i.p. injection of STZ. Diabetic rats were then treated with the zinc-flavonol complex (5 mg/kg, p.o.) for 30 days. The extent of oxidative stress was assessed by determining lipid peroxide levels, pancreatic tissue antioxidant enzyme activities and plasma concentrations of non-enzymatic antioxidants. In addition, nuclear levels of nuclear factor (NF)-κB p65, pancreatic nitric oxide (NO), and plasma levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6 were determined. Pancreatic tissues were examined histologically. Oral treatment with the zinc-flavonol complex significantly improved antioxidant levels and alleviated levels of oxidative stress markers. Furthermore, significant increases were seen in NF-κB p65, NO, TNF-α, IL-1β and IL-6 levels. Histological observations revealed that the zinc-flavonol complex effectively protects pancreatic β-cells against oxidative damage. The results of the present study indicate that the zinc-flavonol complex has an antioxidative and anti-inflammatory role in the diabetic milieu.

Effects of Hydrogen Sulfide on Oxidative Stress, TNF- and #945; Level and Kidney Histological Changes in Cisplatin Nephrotoxicity in Rat

Cisplatin (CP) is an anticancer drug that enhances renal generation of reactive oxygen metabolites, lipid peroxidation and inflammation. This study examined the effect of hydrogen sulfide on lipid peroxidation content, tissue antioxidant enzyme activities and tumor necrosis factor (TNF-α) in cisplatin nephrotoxic rats. Thirty male Sprague-Dawley rats were divided into three groups of 10 rats in each group: control, nephrotoxic and nephrotoxic groups that received single dose 100 µmol/kg NaHS (i.p.). Nephrotoxicity was induced by a single intraperitoneally injection of cisplatin (6 mg/kg b.w.). Five days after cisplatin injection kidney tissue samples removed for laboratory analyses and light microscopy evaluation. Lipid peroxidation content and activities of catalase, superoxide dismutase, glutathione peroxidase and TNF-α were measured in kidney homogenate supernatants. Statistical differences were assessed with one-way ANOVA by SPSS followed by Tukey\'s t-test. P