Relationship of oxidative events and DNA oxidation in SENCAR mice to in vivo promoting activity of phorbol ester-type tumor promoters

The roles of epigallocatechin gallate in the tumor microenvironment, metabolic reprogramming, and immunotherapy

Cancer, a disease that modern medicine has not fully understood and conquered, with its high incidence and mortality, deprives countless patients of health and even life. According to global cancer statistics, there were an estimated 19.3 million new cancer cases and nearly 10 million cancer deaths in 2020, with the age-standardized incidence and mortality rates of 201.0 and 100.7 per 100,000, respectively. Although remarkable advancements have been made in therapeutic strategies recently, the overall prognosis of cancer patients remains not optimistic. Consequently, there are still many severe challenges to be faced and difficult problems to be solved in cancer therapy today. Epigallocatechin gallate (EGCG), a natural polyphenol extracted from tea leaves, has received much attention for its antitumor effects. Accumulating investigations have confirmed that EGCG can inhibit tumorigenesis and progression by triggering apoptosis, suppressing proliferation, invasion, and migration, altering tumor epigenetic modification, and overcoming chemotherapy resistance. Nevertheless, its regulatory roles and biomolecular mechanisms in the immune microenvironment, metabolic microenvironment, and immunotherapy remain obscure. In this article, we summarized the most recent updates about the effects of EGCG on tumor microenvironment (TME), metabolic reprogramming, and anti-cancer immunotherapy. The results demonstrated EGCG can promote the anti-cancer immune response of cytotoxic lymphocytes and dendritic cells (DCs), attenuate the immunosuppression of myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs), and inhibit the tumor-promoting functions of tumor-associated macrophages (TAMs), tumor-associated neutrophils (TANs), and various stromal cells including cancer-associated fibroblasts (CAFs), endothelial cells (ECs), stellate cells, and mesenchymal stem/stromal cells (MSCs). Additionally, EGCG can suppress multiple metabolic reprogramming pathways, including glucose uptake, aerobic glycolysis, glutamine metabolism, fatty acid anabolism, and nucleotide synthesis. Finally, EGCG, as an immunomodulator and immune checkpoint blockade, can enhance immunotherapeutic efficacy and may be a promising candidate for antitumor immunotherapy. In conclusion, EGCG plays versatile regulatory roles in TME and metabolic reprogramming, which provides novel insights and combined therapeutic strategies for cancer immunotherapy.

Expression of estrogen receptor alpha in response to stress and estrogen antagonist tamoxifen in the shell gland of Gallus gallus domesticus: involvement of anti-oxidant system and estrogen

Animals are frequently exposed to various kinds of environmental stressors and estrogen is known to play important role in stress response besides its crucial role in regulation of cellular proliferation, metabolic activity and reproduction. The study investigates the estrogen antagonist, tamoxifen (TM), mediated estrogen receptor alpha (ERα) expression, to modulate stress induced parameters in chickens. The study further explores the activity of superoxide dismutase (SOD), catalase and glutathione peroxidase (GPX) and malonaldehyde (MDA) in brain, ovary and shell gland during water deprivation (WD) and tamoxifen administration in sexually mature chicken. WD and TM administration both decrease the plasma estradiol while WD increases corticosterone. WD also elevates MDA concentration in the brain, ovary and shell gland while TM lowers it. WD and TM administration lowers the specific activity of SOD in brain and shell gland. In contrast, WD increases the specific activity of catalase, GPx and GR in the brain and shell gland, while TM decreases it. It appears that endogenous estradiol plays a crucial role in expression of antioxidant enzymes and tamoxifen acts as an antioxidant by reducing the oxidative stress in chicken. Abundant expression of ERα has been observed in the shell gland of egg laying birds while stress like water deprivation and TM down-regulates its expression. Thus, it can be concluded that expression of ERα in shell gland plays a predominant role in mediating estrogen action in response to water deprivation stress and tamoxifen.

Protective effect of dexpanthenol on cisplatin induced nephrotoxicity in rats

Cisplatin (CIS) is an antineoplastic agent used for treating solid organ tumors. Toxic side effects of CIS treatment include nephrotoxicity, neurotoxicity, ototoxicity, myelosuppression and hepatotoxicity. Dexpanthenol (DEX) exhibits antioxidant and anti-inflammatory effects and protective effects against free oxygen radicals. We investigated the protective effects of DEX on CIS induced nephrotoxicity. Animals were divided into four groups of 10. The control group was given saline. The DEX group was treated with DEX for 10 days. The CIS group was treated with a single dose of CIS. The DEX + CIS group was given a single dose of CIS followed by DEX for 10 days. We found increased levels of malondialdehyde (MDA), blood urea nitrogen (BUN) and creatinine, while superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and myeloperoxidase (MPO) levels were decreased in the CIS group. MDA, BUN and creatinine levels were decreased, while SOD, CAT, GPx and MPO levels were increased in the DEX + CIS group. Renal tubule damage, inflammation and histopathology scores were significantly higher in the CIS group than the control. The DEX + CIS group exhibited less renal tubule damage and inflammation, and lower histopathological assessment scores than the CIS group. Significant cortical tubule damage and interstitial inflammation were observed in the CIS group. Tubule damage was slightly less, and mild tubule dilation and less cast formation were observed in the DEX + CIS group; also, inflammation was less severe than for the CIS group. DEX may have therapeutic potential for treating CIS induced nephrotoxicity due to its antioxidant and anti-inflammatory properties.

Melatonin can be, more effective than N-acetylcysteine, protecting acute lung injury induced by intestinal ischemia-reperfusion in rat model

OBJECTIVES

The current study compared the impact of pretreatment with melatonin and N-acetylcysteine (NAC) on the prevention of rat lung damage following intestinal ischemia-reperfusion (iIR).

METHODS

Twenty-eight Wistar rats were subjected to intestinal ischemia induced by a 60 min occlusion of the superior mesenteric artery, followed by reperfusion for 120 min. Animals were divided into the following groups (n=7 per group): sham, only abdominal incision; SS+iIR, pretreated with saline solution and iIR; NAC+iIR, pretreated with NAC (20 mg/kg) and iIR; MEL+iIR, pretreated with melatonin (20 mg/kg) and iIR. Oxidative stress and inflammatory mediators were measured and histological analyses were performed in the lung tissues.

RESULTS

Data showed a reduction in malondialdehyde (MDA), myeloperoxidase (MPO), and TNF-alpha in the animals pretreated with NAC or MEL when compared to those treated with SS+iIR (p<0.05). An increase in superoxide dismutase (SOD) levels in the NAC- and MEL-pretreated animals as compared to the SS+iIR group (34±8 U/g of tissue; p<0.05) was also observed. TNF-α levels were lower in the MEL+iIR group (91±5 pg/mL) than in the NAC+iIR group (101±6 pg/mL). Histological analysis demonstrated a higher lung lesion score in the SS+iIR group than in the pretreated groups.

CONCLUSION

Both agents individually provided tissue protective effect against intestinal IR-induced lung injury, but melatonin was more effective in ameliorating the parameters analyzed in this study.

Attenuation of Age-Related Hepatic Steatosis by Dunaliella salina Microalgae in Senescence Rats through the Regulation of Redox Status, Inflammatory Indices, and Apoptotic Biomarkers

Background

Hepatic steatosis is the most common type of chronic liver disease and is considered an established risk factor of major chronic diseases.

Purpose

The present study aimed to investigate the effect of Dunaliella salina, a microalga and its isolated zeaxanthin on age-related hepatic steatosis as well as their underling mechanism. Study Design. Age-related hepatic steatosis was induced in rats by intraperitoneal injection of D-galactose (200 mg/kg/day) for eight consecutive weeks. D. salina biomass (BDS; 450 mg/kg), its polar fraction (PDS; 30 mg/kg), carotenoid fraction (CDS; 30 mg/kg), and isolated zeaxanthin heneicosylate (ZH; 250 μg/kg) were orally administered to D-galactose treated rats for two weeks.

Methods

Blood samples were collected 24 hours after the last dose of D. salina treatments, animals were sacrificed, and liver tissues were isolated. Sera as well as hepatic tissue homogenates were used for further investigations. Liver tissues were also used for histopathological and immunohistochemical examinations. A computed virtual docking study for the biologically active candidates was performed to confirm the proposed mechanism of action.

Results

Oral treatment of D-galactose-injected rats with BDS, PDS, CDS, or ZH ameliorated the serum hepatic function parameters as well as serum levels of adiponectin, apolipoprotein B 100, and insulin. Furthermore, D. salina decreased the hepatic lipid contents, redox status biomarkers, inflammatory cytokine, and showing antiapoptotic properties. Molecular docking of β-carotene and zeaxanthin on various receptors involved in the pathophysiological cascade of steatosis highlighted the possible mechanism underlying the observed therapeutic effect.

Conclusion

D. salina carotenoids have beneficial effect on age-related hepatic steatosis in senescence rats through the regulation of redox status, inflammatory indices, and apoptotic biomarkers.

Chemically induced carcinogenesis in rodent models of aging: assessing organismal resilience to genotoxic stressors in geroscience research

There is significant overlap between the cellular and molecular mechanisms of aging and pathways contributing to carcinogenesis, including the role of genome maintenance pathways. In the field of geroscience analysis of novel genetic mouse models with either a shortened, or an extended, lifespan provides a unique opportunity to evaluate the synergistic roles of longevity assurance pathways in cancer resistance and regulation of lifespan and to develop novel targets for interventions that both delay aging and prevent carcinogenesis. There is a growing need for robust assays to assess the susceptibility of cancer in these models. The present review focuses on a well-characterized method frequently used in cancer research, which can be adapted to study resilience to genotoxic stress and susceptibility to genotoxic stress-induced carcinogenesis in geroscience research namely, chemical carcinogenesis induced by treatment with 7,12-dimethylbenz(a)anthracene (DMBA). Recent progress in understanding how longer-living mice may achieve resistance to chemical carcinogenesis and how these pathways are modulated by anti-aging interventions is reviewed. Strain-specific differences in sensitivity to DMBA-induced carcinogenesis are also explored and contrasted with mouse lifespan. The clinical relevance of inhibition of DMBA-induced carcinogenesis for the pathogenesis of mammary adenocarcinomas in older human subjects is discussed. Finally, the potential role of insulin-like growth factor-1 (IGF-1) in the regulation of pathways responsible for cellular resilience to DMBA-induced mutagenesis is discussed.

Astaxanthin-Rich Haematococcus pluvialis Algal Hepatic Modulation in D-Galactose-Induced Aging in Rats: Role of Nrf2

Purpose: Aging is associated with hepatic morphological and physiological deterioration due to the accumulation of endogenous and exogenous free radicals and the resultant oxidative stress. The present study aims to investigate the effect of Haematococcus pluvialis microalgae on hepatic changes associated with D-galactose (D-Gal)-induced aging in rats.

Methods: Aging was induced in rats by daily intraperitoneal injection of D-Gal (200 mg/kg/day) for eight consecutive weeks. D-Gal-injected rats were treated by astaxanthin (ATX)-rich H. pluvialis biomass, its carotenoid and polar fractions for two weeks. Twenty four hours after the last dose, blood samples were collected and the liver tissues were isolated for further biochemical and histopathological examinations.

Results: D-Gal induced aging was associated with an elevation in serum liver function parameters, hepatic oxidative stress biomarkers viz., catalase (CAT), glutathione transferase (GST) and myeloperoxidase (MPO), as well as decreased expression of nuclear factor like-2 (Nrf2). Moreover, induction of aging exhibited an elevation of hepatic inflammatory cytokine; interleukin-6 (IL-6) and its modulator; nuclear factor Kappa B (NF-KB). However, treatment of D-Gal injected rats with ATX-rich H. pluvialis restored the serum liver function parameters as well as hepatic CAT, GST and MPO levels with an elevated expression of Nrf2. Treatment with ATX-rich H. pluvialis was also accompanied with a decrease in hepatic levels of NF-KB and IL-6. Histopathological examination emphasized all the previous results. Similarly, all trans-astaxanthin showed high affinity towards Nrf2 with -7.93 kcal/mol estimated free energy of binding as well as moderate affinities towards IL-6 and NF-KB through a docking study.

Conclusion: ATX-rich H. pluvialis showed beneficial effects by ameliorating the hepatic changes associated with D-Gal induced aging in rats due to its modulatory role of the Nrf2/Keap pathway.

Protective Effect of Infliximab, a Tumor Necrosis Factor-Alfa Inhibitor, on Bleomycin-Induced Lung Fibrosis in Rats

We aimed to investigate the preventive effect of Infliximab (IFX), a tumor necrosis factor (TNF)-α inhibitor, on bleomycin (BLC)-induced lung fibrosis in rats. Rats were assigned into four groups as follows: I-BLC group, a single intra-tracheal BLC (2.5 mg/kg) was installed; II-control group, a single intra-tracheal saline was installed; III-IFX + BLC group, a single-dose IFX (7 mg/kg) was administered intraperitoneally (i.p.), 72 h before the intra-tracheal BLC installation; IV-IFX group, IFX (7 mg/kg) was administered alone i.p. on the same day with IFX + BLC group. All animals were sacrificed on the 14th day of BLC installation. Levels of tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β, interleukin (IL)-6, periostin, YKL-40, nitric oxide (NO) in rat serum were measured, as well as, myeloperoxidase (MPO), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) activity, and reduced glutathione (GSH), hydroxyproline, malondialdehyde (MDA) content in lung homogenates. Lung tissues were stained with hematoxylin and eosin (H&E) for quantitative histological evaluation. The inducible nitric oxide synthase (iNOS) expression and cell apoptosis in the lung tissues were determined quantitatively by immunohistochemical staining (INOS) and by TUNNEL staining, respectively. BLC installation worsened antioxidant status (such as SOD, CAT, GPx, GSH, MPO), while it increased the serum TNF-α, TGF-β, IL-6, periostin, YKL-40, and lipid peroxidation, and collagen deposition, measured by MDA and hydroxyproline, respectively. IFX pretreatment improved antioxidant status as well as BLC-induced lung pathological changes, while it decreased the TNF-α, TGF-β, IL-6, periostin, YKL-40, lipid peroxidation and collagen deposition. Finally, histological, immunohistochemical, and TUNNEL evidence also supported the ability of IFX to prevent BLC-induced lung fibrosis. The results of the present study indicate that IFX pretreatment can attenuate BLC-induced pulmonary fibrosis.

Protective Effect of Micronized Purified Flavonoid Fraction on Ischemia/Reperfusion Injury of Rat Liver

BACKGROUND

Flavonoids have been subjected to considerable investigation because of its antioxidant and anti-inflammatory properties. However, there is no previously reported study about its effect on hepatic ischemia/reperfusion (I/R). We investigated the effects of micronized purified flavonoid fraction (MPFF) on hepatic I/R injury in rats.

METHODS

Thirty rats were recruited in the study as follows: group A, sham operation (n = 10); group B, I/R (n = 10); and group C, I/R+MPFF (n = 10). In group C, rats received (80 mg/kg/day) MPFF by gavage for 3 days before surgery, 30 minutes before ischemia and just before the reperfusion. Blood samples were taken, and serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) levels were measured to assess liver functions. Liver tissues were taken for histological evaluation and to determine the total antioxidant capacity (TAC), catalase (CAT), total oxidant status (TOS), oxidative stress index (OSI), and myeloperoxidase (MPO).

RESULTS

The present data showed a decrease in AST, ALT, and LDH levels in the MPFF-treated rats when compared with I/R group rats (P < .001 for all). In the MPFF-treated rats, tissue levels of TOS, OSI, and MPO were significantly lower than those in the I/R group (P < .01, P < .001, and P < .05, respectively). Increases in TAC and CAT levels were statistically significant in the MPFF-treated rats compared with the I/R group (P = .01 for both). On the other hand, MPFF attenuated histological alterations that were induced by I/R.

CONCLUSIONS

The present study demonstrates that MPFF ameliorates I/R-induced liver damage, probably through antioxidant and anti-inflammatory properties.

Protective Effects of Curcumin on Intestinal Damage in Cholestatic Rats

BACKGROUND

The aim of this study was to evaluate the possible protective effects of curcumin on oxidative stress, cell proliferation, and apoptosis in the rat intestinal mucosa after bile duct ligation (BDL).

METHODS

A total of 18 male Sprague Dawley rats were divided into three groups: sham control, BDL and BDL+curcumin; each group contain six animals. The rats in the curcumin-treated group were given curcumin (100 mg/kg) once a day orally for 14 days, starting 3 days prior to BDL operation. Following 14 days of treatment, all the animals were decapitated and intestinal tissues samples obtained for biochemical and histopathological investigation.

RESULTS

Curcumin treatment was found to significantly lower elevated tissue malondialdehyde levels and myeloperoxidase activity, and to raise reduced glutathione levels in intestinal tissues samples. BDL caused severe histopathological injury, including shortening of the villi, loss of villous epithelium, multiple erosions, inflammatory cell infiltration, necrosis, and hemorrhage into the intestinal wall. Curcumin treatment significantly attenuated the severity of intestinal injury, with inhibition of BDL-induced apoptosis and cell proliferation.

CONCLUSION

Curcumin treatment has a protective effect against intestinal damage induced by BDL. The ability of curcumin treatment is to inhibit BDL-induced oxidative stress, apoptosis, and cell proliferation.

Cancer prevention and therapy through the modulation of the tumor microenvironment

Cancer arises in the context of an in vivo tumor microenvironment. This microenvironment is both a cause and consequence of tumorigenesis. Tumor and host cells co-evolve dynamically through indirect and direct cellular interactions, eliciting multiscale effects on many biological programs, including cellular proliferation, growth, and metabolism, as well as angiogenesis and hypoxia and innate and adaptive immunity. Here we highlight specific biological processes that could be exploited as targets for the prevention and therapy of cancer. Specifically, we describe how inhibition of targets such as cholesterol synthesis and metabolites, reactive oxygen species and hypoxia, macrophage activation and conversion, indoleamine 2,3-dioxygenase regulation of dendritic cells, vascular endothelial growth factor regulation of angiogenesis, fibrosis inhibition, endoglin, and Janus kinase signaling emerge as examples of important potential nexuses in the regulation of tumorigenesis and the tumor microenvironment that can be targeted. We have also identified therapeutic agents as approaches, in particular natural products such as berberine, resveratrol, onionin A, epigallocatechin gallate, genistein, curcumin, naringenin, desoxyrhapontigenin, piperine, and zerumbone, that may warrant further investigation to target the tumor microenvironment for the treatment and/or prevention of cancer.

Nrf2 Activation Promotes Keratinocyte Survival during Early Skin Carcinogenesis via Metabolic Alterations

Pharmacologic activation of the transcription factor NRF2 has been suggested to offer a strategy for cancer prevention. In this study, we present evidence from murine tumorigenesis experiments suggesting there may be limitations to this possibility, based on tumorigenic effects of Nrf2 in murine keratinocytes that have not been described previously. In this setting, Nrf2 expression conferred metabolic alterations in keratinocytes that were protumorigenic in nature, affecting enzymes involved in glutathione biosynthesis or in the oxidative pentose phosphate pathway and other NADPH-producing enzymes. Under stress conditions, coordinate increases in NADPH, purine, and glutathione levels promoted the survival of keratinocytes harboring oncogenic mutations, thereby promoting tumor development. The protumorigenic activity of Nrf2 in keratinocytes was particularly significant in a mouse model of skin tumorigenesis that did not rely upon chemical carcinogenesis. In exploring the clinical relevance of our findings, we confirm that NRF2 and protumorigenic NRF2 target genes were activated in some actinic keratoses, the major precancerous lesion in human skin. Overall, our results reveal an unexpected tumor-promoting activity of activated NRF2 during early phases of skin tumorigenesis.

Evaluation of the cardiovascular effects of varenicline in rats

BACKGROUND

Cardiovascular disease is an important cause of morbidity and mortality among tobacco users. Varenicline is widely used worldwide to help smoking cessation, but some published studies have reported associated cardiovascular events.

OBJECTIVE

To determine the cardiovascular toxicity induced by varenicline in rats.

MATERIALS AND METHODS

We randomly separated 34 rats into two groups: 1) the control group (given only distilled water orally, n=10) and the varenicline group (given 9 μg/kg/day varenicline on days 1-3, 9 μg/kg twice daily on days 4-7, and 18 μg/kg twice daily on days 8-90 [total 83 days], n=24). Each group was then subdivided equally into acute and chronic subgroups, and all rats in these groups were euthanized with anesthesia overdose on days 45 and 90, respectively. Body and heart weights, hemodynamic (mean oxygen saturation, mean blood pressure, and heart rate, electrocardiographic (PR, QRS, and QT intervals) biochemical (oxidants and antioxidants), and histopathological analyses (including immunostaining) were performed.

RESULTS

Acute varenicline exposure resulted in loss of body weight, while chronic varenicline exposure caused heart weight loss and decreased mean blood pressure, induced lipid peroxidation, and reduced antioxidant activity. Both acute and chronic varenicline exposure caused impairment of mean oxygen saturation. QT interval was prolonged in the chronic varenicline group, while PR interval prolongation was statistically significant in both the control and acute varenicline groups. Caspase-9 activity was also significantly increased by chronic exposure. Moreover, histopathological observations revealed severe morphological heart damage in both groups.

CONCLUSION

Adverse effects of chronic varenicline exposure on cardiovascular tissue were confirmed by our electrocardiographic, biochemical, and histopathological analyses. This issue needs to be investigated with new experimental and clinical studies to evaluate the exact mechanism(s) of the detrimental effects of varenicline. Physicians should bear in mind the toxic effects of varenicline on the cardiovascular system when prescribing it for smoking cessation.

Oxidative markers of Myeloperoxidase and Catalase and their diagnostic performance in bipolar disorder

BACKGROUND

Recent researches suggest oxidative stress and generalized inflammatory state to be associated with bipolar I disorder (BID). Our aim is to evaluate Myeloperoxidase (MPO) and Catalase (CAT) activities in BID.

METHODS

73 BID patients and 73 healthy controls were enrolled. Patients were classified into manic, depressive and euthymic state. Serum MPO and CAT were measured in both patients and controls.

RESULTS

CAT activity was significantly lower in controls than manic, depressive and euthymics (p<0.001). MPO activity was significantly higher in controls compared to euthymics (p=0.007) and it was significantly higher in depressives compared to euthymics (p=0.023). CAT was negatively and MPO was positively correlated with disease duration in overall the patients. Positive Predictive Value was 94.5% and Negative Predictive Value was 100% above the cutoff point for CAT activity.

CONCLUSION

MPO and CAT activities are impaired in BID, which may be associated with oxidative stress and inflammation.

Effect of low-level laser therapy on lung injury induced by hindlimb ischemia/reperfusion in rats

To investigate the effect of low-level laser therapy (LLLT 650 nm) on the lung remote organ injury induced by hindlimb ischemia/reperfusion (I/R). The experiments were performed on 50 healthy mature male Wistar rats weighing mean 230 ± 20 g. The rats were randomly allocated into five equal groups as follows: normal group (animals nonmanipulated), sham group (operated with no ischemia), laser group (animals nonmanipulated and irradiated with laser), I/R group, and I/R + LLLT group. Rats were prepared for sterile surgery, and then, right hindlimbs were subjected to I/R induced by the femoral artery occlusion for duration of 120 min, followed by a 60-min reperfusion. The LLLT (K30 handheld probe, AZOR, Technica, Russia, 650 nm, 30 mW, surface area = 1 cm(2), 60 S/cm(2), energy density = 1.8 J/cm(2)) was carried out by irradiating the rats over a unique point on the skin over the right upper bronchus for 5 and 15 min after initiating reperfusion for 3 min. At the end of the trial, rats were euthanized under deep anesthesia and the right lung tissues were removed. Myeloperoxidase (MPO) and superoxide dismutase (SOD) activities and nitric oxide (NO), malondialdehyde (MDA), and glutathione (GSH) levels were measured in the lung tissues. The tissue samples were further examined histopathologically under light microscopy. It was found that I/R elevated MPO activity, MDA, and NO levels accompanied by a reduction in SOD activities and GSH levels (P < 0.05). LLLT restored MDA and NO levels, MPO and SOD activity, GSH levels, and lung injury scores (P < 0.05). In light of these findings, the LLLT has alleviated the lung tissue injuries after skeletal muscle I/R in this experimental model.

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.

Melatonin attenuates lung injury in a hind limb ischemia-reperfusion rat model

OBJECTIVE

This study evaluated the protective antioxidant effect of melatonin on lung injury as a remote organ after skeletal muscle ischemia-reperfusion in rats.

METHODS

Thirty male Wistar rats were allocated randomly into three experimental groups: operated with no ischemia (Sham) group, ischemia-reperfusion group and ischemia-reperfusion+melatonin group. Hind limb ischemia was induced by clamping the femoral artery. After 2h ischemia, the clamp was removed and the animal underwent 24h reperfusion. Rats in the ischemia-reperfusion + melatonin group received melatonin (10 mg/kg i.v.), immediately before the clamp was removed. At the end of the trial, animals were euthanized and the lungs were removed for water content determination, histopathological and biochemical studies.

RESULTS

In the ischemia-reperfusion + melatonin group, tissues showed less intense histological abnormalities such as neutrophilic infiltration, intra-alveolar hemorrhage and edema compared with the ischemia-reperfusion group. Histopathologically, there was a significant difference (P < 0.05) between the two groups. The lung water content in the ischemia-reperfusion + melatonin group was significantly lower than the ischemia-reperfusion group (P < 0.05). Lung tissue myeloperoxidase (MPO) activity and nitric oxide (NO) level were significantly (P < 0.05) increased by ischemia-reperfusion. The increase in these parameters was reduced by melatonin. Comparing the ischemia-reperfusion+melatonin group with the sham group, no significant increase in all analyzed aspects of the research was observed.

CONCLUSIONS

These findings suggest that melatonin has preventive effects in lung tissue injury after transient femoral artery occlusion.

Neuroprotective effect of atorvastatin in spinal cord ischemia-reperfusion injury

OBJECTIVES

Prevention of the development of paraplegia during the repair of the damage caused by descending thoracic and thoracoabdominal aneurysms remains an important issue. Therefore, we investigated the protective effect of atorvastatin on ischemia-induced spinal cord injury in a rabbit model.

METHOD

Thirty-two rabbits were divided into the following four equally sized groups: group I (control), group II (ischemia-reperfusion), group III (atorvastatin treatment) and group IV (atorvastatin withdrawal). Spinal cord ischemia was induced by clamping the aorta both below the left renal artery and above the iliac bifurcation. Seventy-two hours postoperatively, the motor function of the lower limbs of each animal was evaluated according to the Tarlov score. Spinal cord and blood samples were obtained for histopathological and biochemical analyses.

RESULTS

All of the rabbits in group II exhibited severe neurological deficits. Atorvastatin treatment (groups III and IV) significantly reduced the level of motor dysfunction. No significant differences were observed between the motor function scores of groups III and IV at the evaluated time points. Light microscopic examination of spinal cord tissue samples obtained at the 72nd hour of reperfusion indicated greater tissue preservation in groups III and IV than in group II.

CONCLUSION

This study demonstrates the considerable neuroprotective effect of atorvastatin on the neurological, biochemical and histopathological status of rabbits with ischemia-induced spinal cord injury. Moreover, the acute withdrawal of atorvastatin therapy following the induction of spinal cord ischemia did not increase the neuronal damage in this rabbit model.

Silymarin alleviates bleomycin-induced pulmonary toxicity and lipid peroxidation in mice

CONTEXT

The application of bleomycin is limited due to its side effects including lung toxicity. Silymarin is a flavonoid complex isolated from milk thistle [Silybum marianum L. (Asteraceae)] which has been identified as an antioxidant and anti-inflammatory compound.

OBJECTIVE

This study evaluates the effect of silymarin on oxidative and inflammatory parameters in the lungs of mice exposed to bleomycin.

MATERIALS AND METHODS

BALB/c mice were divided into four groups of control, bleomycin (1.5 U/kg), bleomycin plus silymarin (50 and 100 mg/kg). After bleomycin administration, mice received 10 d intraperitoneal silymarin treatment. On 10th day, blood and lung samples were collected for measurement of oxidative and inflammatory factors.

RESULTS

Silymarin led to a decrease in lung lipid peroxidation (0.19 and 0.17 nmol/mg protein) in bleomycin-injected animals. Glutathione-S-transferase (GST) which was inhibited by bleomycin (32.4 nmol/min/mg protein) induced by higher dose of silymarin (41 nmol/min/mg protein). Silymarin caused an elevation in glutathione (GSH): 2.6 and 3.1 µmol/g lung compare with bleomycin-injected animals 1.8 µmol/g lung. Catalase (CAT) was increased due to high dose of silymarin (65.7 µmol/min/ml protein) compare with bleomycin treated-mice. Myeloperoxidase (MPO) which was induced due to bleomycin (p < 0.05) reduced again by high dose of silymarin (0.51 U/min/mg protein). Bleomycin led to an increase in TNF-α and interleukin-6 (IL-6) (7.9 and 11.8 pg/ml). These parameters were reduced by silymarin (p < 0.05).

CONCLUSIONS

Silymarin attenuated bleomycin induced-pulmonary toxicity. This protective effect may be due to the ability of silymarin in keeping oxidant-antioxidant balance and regulating of inflammatory mediator release.

Effect of tramadol on lung injury induced by skeletal muscle ischemia-reperfusion: an experimental study

OBJECTIVE:

To determine whether tramadol has a protective effect against lung injury induced by skeletal muscle ischemia-reperfusion.

METHODS:

Twenty Wistar male rats were allocated to one of two groups: ischemia-reperfusion (IR) and ischemia-reperfusion + tramadol (IR+T). The animals were anesthetized with intramuscular injections of ketamine and xylazine (50 mg/kg and 10 mg/kg, respectively). All of the animals underwent 2-h ischemia by occlusion of the femoral artery and 24-h reperfusion. Prior to the occlusion of the femoral artery, 250 IU heparin were administered via the jugular vein in order to prevent clotting. The rats in the IR+T group were treated with tramadol (20 mg/kg i.v.) immediately before reperfusion. After the reperfusion period, the animals were euthanized with pentobarbital (300 mg/kg i.p.), the lungs were carefully removed, and specimens were properly prepared for histopathological and biochemical studies.

RESULTS:

Myeloperoxidase activity and nitric oxide levels were significantly higher in the IR group than in the IR+T group (p = 0.001 for both). Histological abnormalities, such as intra-alveolar edema, intra-alveolar hemorrhage, and neutrophil infiltration, were significantly more common in the IR group than in the IR+T group.

CONCLUSIONS:

On the basis of our histological and biochemical findings, we conclude that tramadol prevents lung tissue injury after skeletal muscle ischemia-reperfusion.

Effects of rofecoxib, a selective cyclooxygenase-2 inhibitor, on endothelial dysfunction, lipid peroxidation, and hepatocyte morphology in rats with sepsis-induced liver damage

BACKGROUND

Sepsis remains a difficult problem for clinicians, with its systemic effects and high morbidity and mortality rates. The roles of oxidative stress, endothelial dysfunction, and lipid peroxidation in sepsis-induced organ damage are being investigated.

OBJECTIVE

The aim of this study was to investigate the effects of selective cyclooxygenase (COX)-2 inhibition on tissue lipid peroxidation, endothelial dysfunction, and hepatic cell morphology in a rat model of sepsis.

METHODS

Thirty rats with sepsis induced by cecal ligation and puncture were divided equally into 3 groups: treatment group (rofecoxib 1 mg/kg PO), control group (saline 1 mL PO), and sham group (sham surgery only). All the rats were sacrificed 1 day after sepsis induction. The livers were removed using a median laparotomy for histopathologic and biochemical analysis.

RESULTS

Histomorphologic hepatic damage and lipid peroxidation were significantly reduced in the rofecoxib treatment group compared with the control group (P < 0.05 and P = 0.001, respectively). Endothelial nitric oxide synthase and inducible nitric oxide synthase staining of liver samples was statistically significantly reduced in the treatment group compared with the control group (both, P < 0.001). The hepatic nitric oxide level and malonyldialdehyde activity decreased significantly (P < 0.001 and P = 0.001, respectively) in the rofecoxib group compared with the control group. Hepatic myeloperoxidase activity was similar between the treatment and control groups.

CONCLUSION

Further investigation of selective COX-2 inhibition as an alternate therapeutic choice for sepsis-induced hepatic damage should be considered.

WITHDRAWN: Melatonin attenuates lung injury in a hind limb ischemia-reperfusion rat model

This article has been withdrawn for editorial reasons because the journal will be published only in English. In order to avoid duplicated records, this article can be found at http://dx.doi.org/10.1016/j.rppnen.2014.01.010. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

Chard (Beta vulgaris L. var. cicla) extract ameliorates hyperglycemia by increasing GLUT2 through Akt2 and antioxidant defense in the liver of rats

Chard is a plant used as an alternative hypoglycemic agent by diabetic people in Turkey. The aim of this study was to examine the molecular mechanism of hypoglycemic effects of chard extract. Male Sprague-Dawley rats (6-7 months old) were divided into five groups for this investigation: (1) control, (2) hyperglycemic, (3) hyperglycemic+chard, (4) hyperglycemic+insulin, (5) hyperglycemic+chard+insulin. Fourteen days after animals were rendered hyperglycemic by intraperitoneal injection of 60 mg/kg streptozotocin, the chard water extract (2 g/kg/day) or/and insulin (6 U/kg/day) was administered for 45 days. Hypoglycemic effect of chard extract was demonstrated by a significant reduction in the fasting blood glucose and increased glycogen levels in liver of chard extract-treated hyperglycemic rats. Moreover, activity of adenosine deaminase, which is suggested as an important enzyme for modulating the bioactivity of insulin, was decreased by chard treatment. Immunostaining analysis showed increased nuclear translocation of Akt2 and synthesis of GLUT2 in the hepatocytes of chard or/and insulin-treated hyperglycemic rats. The oxidative stress was decreased and antioxidant defense was increased by chard extract or/and insulin treatment to hyperglycemic rats according to the decreased malondialdehyde formation, the activities of catalase, superoxide dismutase, myeloperoxidase and increased glutathione levels. These findings suggest that chard extract might improve glucose response by increasing GLUT2 through Akt2 and antioxidant defense in the liver.

Protective effect of dexpanthenol on bleomycin-induced pulmonary fibrosis in rats

Despite extensive studies, there is no effective treatment currently available other than pirfenidone for idiopathic pulmonary fibrosis. A protective effect of pantothenic acid and its derivatives on cell damage produced by oxygen radicals has been reported, but it has not been tested in bleomycin (BLM)--induced pulmonary fibrosis in rats. Therefore, we aimed to investigate the preventive effect of dexpanthenol (Dxp) on pulmonary fibrosis. Thirty-two rats were assigned to four groups as follows: (1) control group, (2) dexpanthenol (Dxp) group; 500 mg/kg Dxp continued intraperitoneally for 14 days, (3) bleomycin (BLM) group; a single intratracheal injection of BLM (2.5 mg/kg body weight in 0.25-ml phosphate buffered saline), and (4) BLM + Dxp-treated group; 500 mg/kg Dxp was administered 1 h before the intratracheal BLM injection and continued for 14 days i.p. The histopathological grades of lung inflammation and collagen deposition, tissue levels of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and myeloperoxidase (MPO) were measured. BLM provoked inflammation and collagen deposition (p < 0.0001), with a marked increase in myeloperoxidase (MPO) activity resembling increased inflammatory activity (p < 0.0001), which was prevented by Dxp (p < 0.0001, p = 0.02). BLM reduced tissue activities of SOD, GPx, and CAT compared to controls (p = 0.01, 0.03, 0.009). MDA was increased with BLM (p = 0.003). SOD (p = 0.001) and MDA (p = 0.016) levels were improved in group 4. The CAT levels in the BLM + Dxp group were close to those in the control group (p > 0.05). We showed that Dxp significantly prevents BLM-induced lung fibrosis in rats. Further studies are required to evaluate the role of Dxp in the treatment of lung fibrosis.

Can safe and long-term exposure to extremely low frequency (50 Hz) magnetic fields affect apoptosis, reproduction, and oxidative stress?

PURPOSE

To determine whether 50 Hz extremely low frequency-magnetic fields (ELF-MF) affects apoptotic processes, oxidative damage, and reproductive characteristics such as sperm count and morphology in rat testes.

MATERIALS AND METHODS

Thirty male Sprague-Dawley rats were used in the present study, which were divided into three groups (sham group, n = 10, and two experimental groups, n = 10 for each group). Rats in the experimental group were exposed to 100 and 500 μT ELF-MF (2 h/day, 7 days/week, for 10 months) corresponding to exposure levels that are considered safe for humans. The same experimental procedures were applied to the sham group, but the ELF generator was turned off. Tissues from the testes were immunohistochemically stained for active (cleaved) caspase-3 in order to measure the apoptotic index by a semi-quantitative scoring system. The levels of catalase (CAT), malondialdehyde (MDA), myeloperoxidase (MPO), total antioxidative capacity (TAC), total oxidant status (TOS), and oxidative stress index (OSI) were also measured. Additionally, epididymal sperm count and sperm morphology was evaluated.

RESULTS

There were no significant differences in the reproductive and oxidative stress parameters between the sham group and the exposed groups (p > 0.05). While no difference was observed between the final apoptosis score of the sham and the 100 μT ELF-MF group (p > 0.05), the final apoptosis score was higher in the 500 μT ELF-MF exposure group than in the sham group (p < 0.05).

CONCLUSION

Long-term exposure to 100 μT and 500 μT ELF-MF did not affect oxidative or antioxidative processes, lipid peroxidation, or reproductive components such as sperm count and morphology in testes tissue of rats. However, long-term exposure to 500 μT ELF-MF did affect active-caspase-3 activity, which is a well-known apoptotic indicator.

Protective activity of ischemic preconditioning on rat testicular ischemia: effects of Y-27632 and 5-hydroxydecanoic acid

BACKGROUND/PURPOSE

The aim of this study was to investigate the role of ischemic preconditioning (IPC) on ischemia/reperfusion (I/R)-induced injury of rat testis and determine the effects of 5-hydroxydecanoic acid (5-HD), a selective K(ATP) channel antagonist, and Y-27632, a selective Rho kinase inhibitor, on IPC.

METHODS

I/R injury was induced by 180 min ischemia and 60 min reperfusion of testis. There were 5 groups. Group 1 served as untreated controls. The rats in Group 2 were subjected to I/R only. In Group 3, 3 cycles of IPC (5 min transient ischemia plus 5 min reperfusion) were performed prior to I/R. In groups 4 and 5, the rats were treated as in Group 3 but received intraperitoneal injections of 0.3 mg/kg Y-27632 or 10 mg/kg 5-HD prior to IPC, respectively.

RESULTS

I/R led to severe histopathological lesions in the rat testis and significantly lowered the scoring. I/R resulted in significant elevation in tissue lipid peroxide levels, myeloperoxidase (MPO) activity, and total antioxidative capacity (TAC), total oxidative status, and oxidative stress index levels. Protective effects of IPC on I/R-induced testicular injury of rats were observed with the significant recovery in these biochemical parameters. Y-27632 treatment led to a significant decrease in MPO activity, but there were no significant changes in the remaining parameters. Effects of IPC were blocked by 5-HD except in the TAC levels.

CONCLUSION

Our results showed that IPC protected rat testis against I/R-induced injury via activation of KATP channels. Additionally, Rho kinase inhibition preserved the effects of IPC in testis.

Berberine attenuates bleomycin induced pulmonary toxicity and fibrosis via suppressing NF-κB dependant TGF-β activation: a biphasic experimental study

Idiopathic pulmonary fibrosis (IPF) is a progressive, debilitating and fatal lung disorder with high mortality rate. Unfortunately, to date the treatment for IPF remains unsatisfying and in severe cases lung transplantations are performed as a therapeutic measure. Thus, it becomes great interest to find novel agents to treat IPF. Berberine, a plant alkaloid known for its broad pharmacological activities remains a remedy against multiple diseases. This study was hypothesized to investigate the antifibrotic potential of berberine against bleomycin-induced lung injury and fibrosis, a tentative animal model. Male wistar rats were subjected to single intratracheal instillation of 2.5 U/kg of bleomycin on day 0. Berberine treatments were either provided in preventive or therapeutic mode respectively. Berberine administration significantly ameliorated the bleomycin mediated histological alterations and reduced the inflammatory cell infiltrate in BALF. Berberine significantly blocked collagen accumulations with parallel reduction in the hydroxyproline level. The immunological sign of bleomycin stimulated mast cell deposition and histamine release were considerably reduced by berberine. Berberine enhanced the antioxidant status, through upregulating the redox sensing transcription factor nuclear factor E2-related factor 2 (Nrf2). Berberine inhibited the bleomycin mediated activation of inflammatory mediator nuclear factor kappa B (NF-κB) and suppressed its downstream target inducible nitric oxide synthase (iNOS). Strikingly, berberine exhibited target attenuation of tumor necrosis factor alpha (TNF-α) and key pro-fibrotic mediator, transforming growth factor beta 1 (TGF-β1). Taken together, this study reveals the beneficial effects of berberine against bleomycin mediated fibrotic challenge through activating Nrf2 and suppressing NF-κB dependent inflammatory and TGF-β1 mediated fibrotic events.

The protective effects of apocynin on kidney damage caused by renal ischemia/reperfusion

PURPOSE

This experimental study was designed to explore the protective effect of apocynin, the NADPH-oxidase inhibitor, on kidney damage induced by ischemia/reperfusion (I/R) in a rat model.

METHODS

Thirty-two rats were randomly divided into a control group and three I/R groups (1-hour ischemia followed by 23-hour reperfusion). Three I/R groups were treated by apocynin (20 mg/kg, i.p.) at two different time points (before ischemia and during ischemia). The histopathological findings, including apoptotic changes, and also tissue malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathion peroxidase (GPX), reduced glutathione (GSH), myeloperoxidase (MPO), blood urea nitrogen (BUN), and serum creatinine (Cr) levels, were determined.

RESULTS

Kidney tissue MDA and MPO, and serum BUN and Cr levels were found to be significantly higher in the I/R group, but there was no statistically significant difference in the levels of SOD, CAT, GPX, and GSH between the I/R and the control groups. Although apocynin significantly reduced MDA and MPO in group 3 and increased GPX in both treatment groups when compared to the I/R group, the elevated BUN and Cr levels were significantly reduced in treatment groups. Renal I/R injury also induced extensive tubular necrosis, glomerular damage, and apoptosis in the histological evaluation. Apocynin, especially when used during ischemia, ameliorated these histological damages in different amounts in treatment groups.

CONCLUSION

The beneficial effects of apocynin on renal I/R injury were evaluated for the first time.

The effects of hyperbaric oxygen application against cholestatic oxidative stress and hepatic damage after bile duct ligation in rats

BACKGROUND

The aim of this study was to evaluate the preventive and therapeutic potential of hyperbaric oxygen therapy (HBO) on the liver tissue against bile duct ligation (BDL)-induced oxidative damage and fibrosis in rats.

MATERIALS AND METHODS

We divided 32 adult male Sprague Dawley rats into four groups: sham, sham plus HBO, BDL, and BDL plus HBO; each group contained eight animals. We placed the sham plus HBO and BDL plus HBO groups in an experimental hyperbaric chamber in which we administered pure oxygen at 2.5 atmospheres absolute 100% oxygen for 90 min on 14 consecutive days.

RESULTS

The application of BDL clearly increased the tissue malondialdehyde level, myeloperoxidase activity, and hydroxyproline content and decreased the antioxidant enzymes (superoxide dismutase and catalase activities) and glutathione level. Hyperbaric oxygen therapy treatment significantly decreased the elevated tissue malondialdehyde level, myeloperoxidase activity, and hydroxyproline content and increased the reduced superoxide dismutase and catalase activities and glutathione level in the tissues. The changes demonstrating the bile duct proliferation and fibrosis in expanded portal tracts include the extension of proliferated bile ducts into lobules, mononuclear cells, and neutrophil infiltration into the widened portal areas were observed in BDL group. Treatment of BDL with HBO attenuated alterations in liver histology. Alpha smooth muscle actin, cytokeratin-positive ductular proliferation, and the activity of terminal deoxynucleotidyl transferase 2'-deoxyuridine, 5'-triphosphate nick end labeling in the BDL decreased with HBO treatment.

CONCLUSIONS

The data indicate that HBO attenuates BDL-induced oxidative injury, hepatocytes damage, bile duct proliferation, and fibrosis. The hepatoprotective effect of HBO is associated with antioxidative potential.

Beneficial effects of montelukast against methotrexate-induced liver toxicity: a biochemical and histological study

The effects of montelukast against methotrexate-induced liver damage were investigated. 35 Wistar albino female rats were divided into 5 groups as follows: group I: control; group II: montelukast (ML); group III: methotrexate (Mtx); group IV: montelukast treatment after methotrexate application (Mtx + ML); group V: montelukast treatment before methotrexate application (ML + Mtx). At the end of the experiment, the liver tissues of rats were removed. Malondialdehyde (MDA), myeloperoxidase (MPO), and reduced glutathione levels were determined from liver tissues. In addition, the liver tissues were examined histologically. MDA and MPO levels of Mtx group were significantly increased when compared to control group. In Mtx + ML group, these parameters were decreased as compared to Mtx group. Mtx injection exhibited major histological alterations such as eosinophilic staining and swelling of hepatocytes. The glycogen storage in hepatocytes was observed as decreased by periodic acid schiff staining in Mtx group as compared to controls. ML treatment did not completely ameliorate the lesions and milder degenerative alterations as loss of the glycogen content was still present. It was showed that montelukast treatment after methotrexate application could reduce methotrexate-induced experimental liver damage.

Beneficial effects of montelukast against cisplatin-induced acute renal damage in rats

OBJECTIVE

In this study, the therapeutic and protective effects of montelukast against cisplatin (CP)-induced acute renal damage were investigated.

MATERIALS AND METHODS

Thirty-five female rats were divided into five groups as follows: (1) control, (2) montelukast (10 mg/kg daily for 10 days per-oral (p.o.), (3) CP (single dose 7 mg/kg intraperitoneally (i.p.)), (4) CP + montelukast (10 mg/kg daily for 10 days p.o., after 3 days of the injection of CP), (5) montelukast (10 mg/kg daily for 10 days p.o.) + CP (single dose 7 mg/kg i.p., after the last dose of montelukast). At the end of the experiment, malondialdehyde (MDA), a lipid peroxidation product, myeloperoxidase (MPO), and reduced glutathione (GSH) levels were determined in the renal tissue. Also, blood urea nitrogen (BUN) and creatinine (Cr) levels were assayed from the trunk blood samples.

RESULTS

CP treatment caused a significant elevation of MDA, MPO, BUN, and Cr levels when compared with the control group. Also, GSH levels were found to be reduced due to the CP treatment. Montelukast administration after CP injection ameliorated all of these parameters. Our histopathological findings (marked swelling of epithelial cells, tubular dilatation, tubular desquamation, and loss of brush border in the kidney) were consistent with the biochemical results.

CONCLUSION

Montelukast treatment after CP injection exerted therapeutic effects against CP-induced acute kidney damage.

Protective effect of bilberry (Vaccinium myrtillus) against doxorubicin-induced oxidative cardiotoxicity in rats

BACKGROUND

Doxorubicin (DOX) is a commonly used chemotherapeutic agent. It is associated with serious dose-limiting cardiotoxicity, which is at least partly caused by generation of reactive oxygen species (ROS). Supplementations with bilberries were effective in reducing oxidative stress in many tissue injuries due their high content of antioxidants. The present study investigated the potential protective effect of bilberry extract against DOX-induced cardiotoxicity in rats.

MATERIAL/METHODS

Rats were treated orally with a methanolic extract of bilberry for 10 days. DOX was injected intraperitoneally on day 7. Twenty-four hours after the last bilberry administration, rats were subjected to ECG study. Blood was then withdrawn and cardiac tissues were dissected for assessment of oxidative stress and cardiac tissue injury. Cardiac tissues were also subjected to histopathological examination.

RESULTS

Bilberry extract significantly inhibited DOX-provoked reduced glutathione depletion and accumulation of oxidized glutathione, malondialdehyde and protein carbonyls in cardiac tissues. This was accompanied by significant amelioration of reduced cardiac catalase, superoxide dismutase, and glutathione peroxidase activities; and increased cardiac myeloperoxidase activity in response to DOX challenge. Pretreatment with bilberry significantly guarded against DOX-induced increase in serum activities of lactate dehydrogenase, creatine phosphokinase and creatine kinase-MB, as well as the level of troponin I. Bilberry alleviated ECG changes in rats treated with DOX and attenuated its pathological changes.

CONCLUSIONS

Bilberry protects against DOX-induced cardiotoxicity in rats. This can be attributed, at least in part, to its antioxidant activity.

Farnesol attenuates 1,2-dimethylhydrazine induced oxidative stress, inflammation and apoptotic responses in the colon of Wistar rats

Colon cancer is the major health hazard related with high mortality and it is a pathological consequence of persistent oxidative stress and inflammation. Farnesol, an isoprenoid alcohol, has been shown to possess antioxidant, anti-inflammatory and chemopreventive properties. The present study was performed to evaluate the protective efficacy of farnesol against 1,2-dimethylhydrazine (DMH) induced oxidative stress, inflammatory response and apoptotic tissue damage. Farnesol was administered once daily for seven consecutive days at the doses of 50 and 100 mg/kg body weight in corn oil. On day 7, a single injection of DMH was given subcutaneously in the groin at the dose of 40 mg/kg body weight. Protective effects of farnesol were assessed by using caspase-3 activity, tissue lipid peroxidation (LPO) and antioxidant status as end point markers. Further strengthening was evident on histopathological observations used to assess the protective efficacy of farnesol. Prophylactic treatment with farnesol significantly ameliorates DMH induced oxidative damage by diminishing the tissue LPO accompanied by increase in enzymatic viz., superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST) and quinone reductase (QR) and non-enzymatic viz., reduced glutathione (GSH) antioxidant status. Farnesol supplementation significantly decreased caspase-3 activity in colonic tissue. Histological findings also revealed that pretreatment with farnesol significantly reduced the severity of submucosal edema, regional destruction of the mucosal layer and intense infiltration of the inflammatory cells in mucosal and submucosal layers of the colon. The data of the present study suggest that farnesol effectively suppress DMH induced colonic mucosal damage by ameliorating oxidative stress, inflammatory and apoptotic responses.

Effects of extremely low-frequency magnetic field on caspase activities and oxidative stress values in rat brain

This study was aimed to investigate the effect of extremely low-frequency magnetic field (ELF-MF) on apoptosis and oxidative stress values in the brain of rat. Rats were exposed to 100 and 500 µT ELF-MF, which are the safety standards of public and occupational exposure for 2 h/day for 10 months. Brain tissues were immunohistochemically stained for the active (cleaved) caspase-3 in order to measure the apoptotic index by a semi-quantitative scoring system. In addition, the levels of catalase (CAT), malondialdehyde (MDA), myeloperoxidase (MPO), total antioxidative capacity (TAC), total oxidant status (TOS), and oxidative stress index (OSI) were measured in rat brain. Final score of apoptosis and MPO activity were not significantly different between the groups. CAT activity decreased in both exposure groups (p < 0.05), while TAC was found to be lower in ELF 500 group than those in ELF-100 and sham groups (p < 0.05). MDA, TOS, and OSI values were found to be higher in ELF-500 group than those in ELF-100 and sham groups (p < 0.05). In conclusion, apoptosis was not changed by long-term ELF-MF exposure, while both 100 and 500 µT ELF-MF exposure induced toxic effect in the rat brain by increasing oxidative stress and diminishing antioxidant defense system.

Purified micronized flavonoid fraction ameliorates the injury of spleen and ileum secondary to hepatic ischemia-reperfusion in rats

BACKGROUND

Flavonoids have been subjected to considerable investigations due to their antioxidant and anti-inflammatory properties. Yet the effects of flavonoids on the ileum and spleen against hepatic ischemia-reperfusion injury have so far not been addressed.

AIMS

We aimed to investigate whether micronized purified flavonoid fraction (MPFF) protects the ileum and spleen against hepatic ischemia-reperfusion injury.

METHODS

Rats were subjected to hepatic ischemia by clamping the hilar area of the rats for 60 min, followed by 60 min of reperfusion. Rats in the treatment group were treated with MPFF (80 mg/kg/day) by gavage for 3 days before surgery, 30 min prior to ischemia and just before the reperfusion. After the reperfusion period, all rats were sacrificed. Ileal and splenic tissues were taken for histological evaluation and determination of the total antioxidant capacity (TAC), catalase, total oxidant status (TOS), oxidative stress index (OSI) and myeloperoxidase (MPO) levels.

RESULTS

TAC levels in the splenic tissue and intestinal tissue were significantly higher in the treatment group than in the control group (P < 0.01 for both). TOS, OSI, and MPO in splenic tissue (P < 0.01, P < 0.05, and P < 0.05, respectively) and intestinal tissue (P < 0.01, P < 0.01, and P < 0.001, respectively) were significantly lower in the treatment group than in the control group. Histological tissue damage of intestinal tissue was milder in the treatment group than in the control group.

CONCLUSION

The results of this study indicated that MPFF pretreatment significantly limited the injury to the small intestine and spleen induced by hepatic ischemia-reperfusion in rats.