Antioxidant enzymes in hypercholesterolemia and effects of vitamin E in rabbits

Evaluating oxidative stress biomarkers in oncology nurses exposed to antineoplastic drugs: A cross-sectional study

PURPOSE

Antineoplastic drugs (ADs) are widely used in cancer treatment. Nurses in chemotherapy centers are exposed to these drugs during preparation. They can affect healthy cells, leading to teratogenic and mutagenic effects, as well as oxidative stress. This study aimed to evaluate oxidative stress biomarkers in the nurses exposed to these drugs.

METHOD

This study was conducted on 30 nurses exposed to ADs and 30 nurses with no exposure to these drugs as non-exposed group. Oxidative stress biomarkers were measured in the blood serum samples of both groups, including malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), total antioxidant capacity (TAC), and blood thiol groups.

RESULTS

Considering the possibility of confounding effect of nutritional supplement consumption, the effect of this factor was adjusted in the analysis. A significant difference was observed for CAT, SOD, thiol, and TAC biomarkers between two groups (P < 0.05). However, the difference in MDA and GPx biomarkers between two groups was not statistically significant.

CONCLUSIONS

The findings of the present study showed that supplement consumption has a significant effect on the biomarker of total antioxidant capacity. Thus, total antioxidant capacity measurement is advised as the best biomarker for tracking oxidative status in nurses exposed to ADs due to its capacity to measure all antioxidants in the body, except the thiol group, and its lower cost when compared to other biomarkers. Furthermore, it can be claimed that the consumption of nutritional supplements has a greater effect on the non-enzymatic biomarkers of oxidative stress than on enzymatic antioxidant system.

Seasonal plasticity in immunocompetent cytokines (IL-2, IL-6, and TNF-α), myeloid progenitor cell (CFU-GM) proliferation, and LPS-induced oxido-inflammatory aberrations in a tropical rodent Funambulus pennanti: role of melatonin

In seasonal breeders, photoperiods regulate the levels of circulatory melatonin, a well-known immunomodulator and an antioxidant. Melatonin is known to play a complex physiological role in maintaining the immune homeostasis by affecting cytokine production in immunocompetent cells. In this study, we have quantified seasonal and temporal variations in immunocompetent cytokines-IL-2, IL-6, and TNF-α-and circulatory corticosterone along with in- vitro proliferation of bone marrow-derived granulocyte macrophage-colony forming unit (CFU-GM) progenitor cells of a tropical seasonal breeder Funambulus pennanti (northern palm squirrel). Transient variations in antioxidant status of seasonal breeders might be due to the fluctuations associated with immunity and inflammation. Further, to establish a direct immunomodulatory effect of photoperiod, we recorded the LPS-induced oxidative and inflammatory responses of squirrels by housing them in artificial photoperiodic chambers mimicking summer and winter seasons respectively. We observed a marked variation in cytokines level, melatonin, and corticosterone , and CFU-GM cell proliferation during summer and winter seasons. High Peripheral melatonin levels directly correlated with cytokine IL-2 levels, and inversely correlated with TNF-α, and circulatory corticosterone level. LPS-challenged squirrels housed in short photoperiod (10L:14D; equivalent to winter days) showed a marked reduction in the components of the inflammatory cascade, CRP, TNF-α, IL-6, NOx, NF-κB, Cox-2, and PGES, with an overall improvement in antioxidant status when compared to squirrels maintained under a long photoperiod (16L:8D; equivalent to summer days). Our results underline the impact of seasonality, photoperiod, and melatonin in maintaining an intrinsic redox-immune homeostasis which helps the animal to withstand environmental stresses.

Polystyrene microplastics enhanced copper-induced acute immunotoxicity in red swamp crayfish (Procambarus clarkii)

Microplastic pollution has attracted a lot of attention in recent years. Not only can it be ingested by animals, but it can easily become a carrier of other pollutants, forming a composite pollutant with potentially toxic effects on organisms. We investigated the effect of Cu on the accumulation of polystyrene microplastics (PS) in the gills of Procambarus clarkii and whether PS exacerbated the immune toxicity of Cu to P. clarkii were exposed to Cu, PS and PS+Cu for 48 h, the accumulation of PS in gill and hepatopancreas immune and antioxidant indices were analyzed. The objective was to investigate the toxic effects of Ps and Cu compound pollutants on P. clarkii and whether the accumulated pollutants would cause food safety problems. The results showed that microplastic particles adhered to each other and aggregated in the PS+Cu group, and the number of microplastic particles in gill in the PS+Cu group was significantly lower than that in the PS group. Compared with the other two treatment groups, SOD, CAT, GPx activities and MDA content increased significantly in the PS+Cu group and were relatively delayed. At 12 h, 24 h, 36 h and 48 h, the SOD mRNA expression levels in the PS+Cu group were all significantly lower than those in the Cu group (P < 0.05). At 24 h and 48 h, CAT mRNA expression in the PS+Cu group was significantly higher than that in the Cu group (P < 0.05). Crustin 4 mRNA expressions in the PS+Cu group was significantly higher than that in the Cu group at 12 h and 36 h (P < 0.05). The results demonstrate that the PS and Cu compound reduced the accumulation of microplastic particles in the gill. PS particles delayed Cu entry into P. clarkii for a short time (12 h) and reduced the toxic effect, but with the increase of exposure time (24 h and 48 h), the toxic effect of PS and Cu complexes on P. clarkii increases, and the large accumulation of PS and Cu complexes may cause food safety problems.

Febuxostat treatment attenuates oxidative stress and inflammation due to ischemia-reperfusion injury through the necrotic pathway in skin flap of animal model

BACKGROUND

Ischemia-reperfusion (I/R) injury is a major contributor to skin flap necrosis, which is a serious complication of reconstructive surgery. The purpose of this study was to evaluate the protective effect of treatment with febuxostat, a selective xanthine oxidase inhibitor, on I/R injury in the skin flap of an animal (rat) model.

METHODS

Superficial epigastric flaps were raised in Sprague-Dawley rats and subjected to ischemia for 3 h. Febuxostat at a dose of 10 mg/kg/day was administered to rats in drinking water from 1 week before the surgery (Feb group). Control animals received no drugs (Con group). The mean ratio of flap survival and contraction was evaluated and compared between animals with and without administration of febuxostat on day 5 after the surgery. In addition, infiltration by polymorphonuclear leukocytes and muscles of the panniculus carnosus in the flap were histologically evaluated using hematoxylin-eosin staining. Furthermore, xanthine oxidase activity, ATP levels, superoxide dismutase activity, and expression of 8-hydroxy-2'-deoxyguanosine (8-OHdG), tumor necrosis factor-α, and interleukin-1β were quantitatively assessed in the skin flap 24 h after the surgery.

RESULTS

In the Feb group, the survival and contraction rates at the 5 d timepoint post-surgery were significantly higher and lower than those in the Con group, respectively. Histological analysis showed significant reduction in polymorphonuclear leukocyte infiltration and muscle injury scores due to I/R injury in the Feb group. The expression of 8-OHdG was also significantly inhibited in animals administered febuxostat. Biochemical analysis showed a significant reduction in xanthine oxidase activity and significant increases in ATP levels and superoxide dismutase activity in the Feb group. Furthermore, the expression of interleukin-1β was significantly lower in the Feb group than in the Con group.

CONCLUSION

Febuxostat, which is clinically used for the treatment of hyperuricemia, was effective against necrosis of the skin flap via inhibition of oxidative stress and inflammation caused by I/R injury.

Examination of the effect of curcumin in experimental liver damage created by diethylnitrosamine in swiss albino mice to superoxide dismutase and catalase activities and glutathione, malondialdehyde, advanced oxidation protein products levels

In this study, the effects of curcumin, glutathione (GSH), malondialdehyde (MDA) levels, advanced protein oxidation products (AOPP), superoxide dismutase (SOD) and catalase (CAT) activities in experimental liver damage with diethylnitrosamine (DEN) in Swiss albino mice were investigated. Subjects (n = 9) were divided into 5 as tumor control 1, tumor control 2, curcumin preservative and treatment, and healthy controlgroup. Curcumin oral gavage (in 150 mg/kg of ethylalcohol) was given to the protecting group for 19 days, 5 days before the administration of Diethylnitrosamine, and 24 hours after the administration of Diethylnitrosamine. 100 μl of ethylalcohol oral gavage was given to the healthy group for 19 days. While MDA levels decreased significantly in the curcumin preservative group (p<0.05) (p = 0.002), the decrease was not significant in the treatment groups (p>0.05), (p = 0.128). AOPP levels decreased significantly in the curcumin protective group (p<0.05) (p = 0.009) but the decrease in the treatment group was not found significant (p> 0.05), (p = 0.073). SOD activities increased significantly in both groups. It was found as (p<0.05), (p = 0.001) and (p<0.05), (p = 0.002), respectively. GSH levels decreased but these reductions were not found statistically significant. CAT activities increased significantly in both groups. It was determined as (p<0.05), (p = 0.001) for both groups. The significant CAT activities were found in both the curcumin protective group and the curcumin treatment group AOPP values decreased in curcumin protective group MDA levels decreased significantly in the curcumin protective group This article is protected by copyright. All rights reserved.

Modulatory effect of fructooligosaccharide against triphenyltin-induced oxidative stress and immune suppression in goldfish (Carassius auratus)

Triphenyltin (TPT) is a widely used pesticide that is highly toxic to a variety of organisms, including humans, and is a potential contributor to environmental pollution. The present study was conducted to evaluate the oxidative stress and immunotoxicity induced by TPT in goldfish (Carassius auratus) and the protective effects of fructooligosaccharide (FOS). Goldfish (mean weight of 13.3 ± 0.2 g) were randomly divided into six groups with three replicates: (G1) the control group, (G2) the 10 ng/L TPT group, (G3) the 0.4% FOS group, (G4) the 10 ng/L TPT + 0.4% FOS group, (G5) the 0.8% FOS group, and (G6) the 10 ng/L TPT + 0.8% FOS group. The results showed that 10 ng/L TPT induced oxidative stress and significantly decreased the activities of antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), in the liver and the gene expression of SOD, GPx, metallothionein (MT), and peroxiredoxin-4 (Prdx-4). The concentration of malondialdehyde (MDA) and the gene expression of cytochrome P450 (CYP) and glutathione S-transferase (GST) in the liver were significantly increased in the TPT-treated group. Exposure to 10 ng/L TPT in water induced immune suppression and significantly decreased the activities of immune enzymes, such as lysozyme, myeloperoxidase (MPO), alternative complement (ACH50), acid phosphatase (ACP) and alkaline phosphatase (AKP), in the serum. TPT could stimulate the fish to generate large amounts of proinflammatory cytokines, including increased tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), and nitric oxide (NO) levels and TNF-α, IL-6, IL-1β, and NF-κB mRNA expression. However, TPT-induced toxicity was significantly ameliorated in the groups treated with FOS, and FOS partly prevented alterations in the activities of antioxidant enzymes and the expression of antioxidant- and ROS scavenger-related genes. In addition, TPT-induced immune toxicity was significantly ameliorated in the groups treated with FOS. FOS markedly suppressed TNF-α, IL-6, IL-1β, and NO production and TNF-α, IL-6, and IL-1β mRNA expression in the TPT-treated groups. The study indicated that TPT-induced oxidative stress may play a critical role in inhibiting immunity. However, FOS administration attenuates TPT-induced oxidative stress and immune suppression in goldfish.

In Vivo Studies of Inoculated Plants and In Vitro Studies Utilizing Methanolic Extracts of Endophytic Streptomyces sp. Strain DBT34 Obtained from Mirabilis jalapa L. Exhibit ROS-Scavenging and Other Bioactive Properties

Reactive oxygen species (ROS) and other free radicals cause oxidative damage in cells under biotic and abiotic stress. Endophytic microorganisms reside in the internal tissues of plants and contribute to the mitigation of such stresses by the production of antioxidant enzymes and compounds. We hypothesized that the endophytic actinobacterium Streptomyces sp. strain DBT34, which was previously demonstrated to have plant growth-promoting (PGP) and antimicrobial properties, may also have a role in protecting plants against several stresses through the production of antioxidants. The present study was designed to characterize catalase and superoxide dismutase (SOD), two enzymes involved in the detoxification of ROS, in methanolic extracts derived from six endophytic actinobacterial isolates obtained from the traditional medicinal plant Mirabilis jalapa. The results of a preliminary screen indicated that Streptomyces sp. strain DBT34 was the best overall strain and was therefore used in subsequent detailed analyses. A methanolic extract of DBT34 exhibited significant antioxidant potential in 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) assays. The cytotoxicity of DBT34 against liver hepatocellular cells (HepG2) was also determined. Results indicated that methanolic extract of Streptomyces sp. strain DBT34 exhibited significant catalase and SOD-like activity with 158.21 U resulting in a 55.15% reduction in ROS. The IC₅₀ values of a crude methanolic extract of strain DBT34 on DPPH radical scavenging and ABTS radical cation decolorization were 41.5 µg/mL and 47.8 µg/mL, respectively. Volatile compounds (VOC) were also detected in the methanolic extract of Streptomyces sp. strain DBT34 using GC-MS analysis to correlate their presence with bioactive potential. Treatments of rats with DBT34 extract and sitagliptin resulted in a significant (p ≤ 0.001) reduction in total cholesterol, LDL-cholesterol, and VLDL-cholesterol, relative to the vehicle control and a standard diabetic medicine. The pancreatic histoarchitecture of vehicle control rats exhibited a compact volume of isolated clusters of Langerhans cells surrounded by acinies with proper vaculation. An in-vivo study of Streptomyces sp. strain DBT34 on chickpea seedlings revealed an enhancement in its antioxidant potential as denoted by lower IC₅₀ values for DPPH and ABTS radical scavenging activity under greenhouse conditions in relative comparison to control plants. Results of the study indicate that strain DBT34 provides a defense mechanism to its host through the production of antioxidant therapeutic agents that mitigate ROS in hosts subjected to biotic and abiotic stresses.

Nesfatin-1 ameliorates type-2 diabetes-associated reproductive dysfunction in male mice

PURPOSE

The present study was aimed to demonstrate the recuperative effect of nesfatin-1 on testicular dysfunction in the high-fat diet (HFD)/streptozotocin (STZ)-induced type-2 diabetes mellitus (T2DM) mice.

METHOD AND RESULTS

Three experimental groups were formed: (1) vehicle control (VC), (2) T2DM mice, (3) T2DM + nesf-1. The mice with blood glucose level higher than 300 mg/dL following HFD and a single dose of STZ were used for the experiment. The T2DM mice showed increases in body mass, blood glucose and insulin levels, reductions in spermatogenesis and steroidogenesis, production of antioxidative enzymes, and disturbed lipid profile. These alterations were all ameliorated by administration of nesfatin-1 at 20 μg/Kg BW for 15 days. Nesfatin-1 treatment also increased the production of testosterone (T), improved insulin sensitivity, and effectively ameliorated the testicular aberrations, and increased spermatogenesis and steroidogenesis. In addition, nesfatin-1 treatment upregulated the PCNA and Bcl2 expression and inhibited the caspase-3 and prohibitin expression in T2DM mice. Nesfatin-1 increased insulin receptor (IR) and GLUT8 expressions, and lactate production, the changes that further substantiate the increase of energy influx to the testis.

CONCLUSION

Altogether, the results suggest the ameliorative effect of nesfatin-1 against T2DM-associated testicular dysfunctions and improved insulin sensitivity along with promoting T production and fertility in T2DM mice.

Direct actions of adiponectin on changes in reproductive, metabolic, and anti-oxidative enzymes status in the testis of adult mice

Obesity is a major health problem that is linked to decreased sperm count. It is hypothesized that an obesity-associated reduction in adiponectin secretion may be responsible for impairment of spermatogenesis. Therefore, the aim of the study was to evaluate the direct role of adiponectin in spermatogenesis and steroid synthesis in adult mice. This study showed that adiponectin receptors (AdipoR1 and AdipoR2) were localized in Leydig cells and seminiferous tubules in the testis of adult mice. The result of the in vitro study showed the direct action of adiponectin on spermatogenesis by stimulating cell proliferation (PCNA) and survival (Bcl2) and by suppressing cell apoptosis. Treatment of testis with adiponectin also enhanced transport of the energetic substrates glucose and lactate to protect cells from undergoing apoptosis. Adiponectin treatment further showed a significant reduction in oxidative stress and nitric oxide. Our findings suggest that adiponectin effectively facilitates cell survival and proliferation, as well as protects from apoptosis. Thus, adiponectin treatment may be responsible for enhancing sperm counts. Interestingly, this study showed the stimulatory effect of adiponectin in spermatogenesis but showed an inhibitory effect on testosterone and estradiol synthesis in the testes. Based on the present study, it is hypothesized that systemic adiponectin treatment may be a promising therapeutic strategy for the improvement of spermatogenesis and sperm count.

Effect of febuxostat on biochemical parameters of hyperlipidemia induced by a high-fat diet in rabbits

Febuxostat, a highly potent xanthine oxidase inhibitor with an antioxidant effect, inhibits elevated xanthine oxidase, leading to reduction of reactive oxygen species and oxidative stress, the main causes of vascular inflammation in hyperlipidemia. The aim of this study was to test the potential antioxidant and anti-inflammatory effects of febuxostat and (or) stopping a high-fat diet on the biochemical parameters in rabbits with hyperlipidemia induced by a high-fat diet. Male New Zealand rabbits were distributed into 3 groups: a normal control group fed standard chow for 12 weeks and 2 other groups fed a high-fat diet with 1% cholesterol for 8 weeks, and then shifted to standard chow for 4 weeks. During the last 4 weeks, one high-fat diet group received 0.5% carboxymethyl cellulose, whereas the other group was treated with febuxostat (2 mg/kg per day p.o.). Febuxostat significantly lowered low-density lipoprotein cholesterol (“bad” cholesterol) compared to the untreated group (high-fat diet group). Febuxostat also displayed a potent anti-inflammatory and antioxidant activity by decreasing serum levels of lipid peroxidation index, proinflammatory cytokines, and enhancing antioxidant enzyme activity. Stopping the hyperlipidemic diet in the high-fat diet group did not show improvement. These findings indicate the antioxidant and anti-inflammatory effects of febuxostat that may be common mechanisms of the anti-hyperlipidemic effect of this drug. Stopping a hyperlipidemic diet without treatment is not sufficient once injury has occurred.

Antioxidant and antihyperlipidemic activity of Costus speciosus against atherogenic diet-induced hyperlipidemia in rabbits

OBJECTIVE

An extract of Costus speciosus (CSE), a herb widely used in folk medicine, was evaluated for its antioxidant, antihyperlipidemic and ameliorating effects on histopathological changes in atherogenic rabbits.

METHODS

Twenty-four male rabbits (Oryctolagus cuniculus) were divided into 4 groups. Three groups were fed a diet containing 3% saturated fat and 1.3% cholesterol for 40 d. One of these was sacrificed on the 40th day and was called the pathogenic (P) group; the other two groups received treatment for another 30 d as follows: one received 0.8 g/(kg·d) of CSE and the other was given 0.01 g/(kg·d) of simvastatin. The normal group was sacrificed on the 70th day and used as a control.

RESULTS

CSE showed radical-scavenging ability. Administration of CSE for a 30-day period resulted in a significant decrease in total cholesterol, triacylglycerol, low-density lipoprotein and aspartate aminotransferase compared to the P group, while levels of hemoglobin, packed corpuscular volume and red blood cells were elevated. With respect to studies performed on the heart, a decrease in malondialdehyde and an increase in reduced glutathione were noted. Total protein increased in the liver, heart and aorta after treatment with CSE and also a marked improvement in histopathological parameters was demonstrated.

CONCLUSION

The present findings indicate that the C. speciosus rhizome possesses antiatherogenic and antioxidant properties which may provide protective effects against oxidative stress in atherosclerotic rabbits.

Direct effects of neuropeptide nesfatin-1 on testicular spermatogenesis and steroidogenesis of the adult mice

Recent studies have revealed nesfatin-1 as a hypothalamic neuropeptide, regulating food intake, energy expenditure and reproduction primarily by acting on the hypothalamic-pituitary-gonadal axis. Nesfatin-1 is also localized in several peripheral tissues including testes. However, functional significance of nesfatin-1 in testicular activities is not yet well documented in mammals. Therefore, this study was aimed to elucidate the direct effects of nesfatin-1 on testicular markers for steroid productions, spermatogenesis, metabolic changes and oxidative stress. The results revealed the expression of both protein and mRNA of nesfatin-1 in the testes of adult mice. The testes treated in vitro with nesfatin-1 showed significant increase in testosterone production, which correlated significantly with increased expression of steroidogenic markers and insulin receptor proteins in the testes. Furthermore, the in vitro treatment with nesfatin-1 showed stimulatory effects on spermatogenesis by promoting cell proliferation (PCNA) and survival (Bcl2), while inhibiting apoptosis (caspase-3) in the testes. The nesfatin-1 treatment in vitro further increased the expression of insulin receptor and GLUT8 proteins, in parallel with increase in the intra-testicular transport of glucose and production of lactate. This nesfatin-1 induced enhanced transport of energy substrate (glucose and lactate) may be responsible for promoting spermatogenesis and steroidogenesis. Nesfatin-1 significantly reduced oxidative stress and nitric oxide, which may also be responsible for stimulatory effects on testicular activities. The present finding suggests that nesfatin-1 acts via paracrine manner to increase sperm count and fertility, thus promoting the testicular function.

The effect of purslane hydroextract and zinc on performance, antioxidant capacity and immunity of broiler chickens during summer conditions

Abstract. Due to negative effects of high ambient temperature, the present study was conducted to investigate the effects of Portulaca oleracea hydroextract (PHE) and zinc (Zn) on the growth performance and immunity of broiler chickens reared under high summer ambient temperature conditions. A total of 420 day-old male broiler chickens (Ross 308) were randomly allocated to seven dietary treatments each replicated four times with 15 birds per replicate. The basal diet as the control diet was supplemented with 100 mg kg−1 butylated hydroxytoluene (BHT), or 300 and 600 mg kg−1 of PHE, 100 mg kg−1 of zinc and 100 mg kg−1 of zinc plus 300 or 600 mg kg−1 of PHE (ZP300 and ZP600). The result of the present study showed that Zn, PHE and their combination did not alter daily feed intake and feed conversion ratio. Although there was a tendency toward an increase in broiler body weight at 24 and 44 days of age (P=0.059 and P=0.061), the body weight of birds fed the basal diet supplemented with Zn reduced at day 10. The birds fed diets supplemented with BHT or ZP600 showed lower aspartate aminotransferase (ASAT) and lactate dehydrogenase activity at 24 days of age (P<0.05), but it remains lower in the ZP600 group only for ASAT activity level at day 44. The results of the present study suggest that dietary PHE and Zn supplementation partially improved body weight and serum antioxidant capacity, superoxide dismutase activity and antibody titer against sheep red blood cells and Newcastle diseases in the broiler chickens during summer conditions.

2.45 GHz microwave radiation induced oxidative and nitrosative stress mediated testicular apoptosis: Involvement of a p53 dependent bax-caspase-3 mediated pathway

Deleterious effects of MW radiation on the male reproduction are well studied. Previous reports although suggest that 2.45 GHz MW irradiation induced oxidative and nitrosative stress adversely affects the male reproductive function but the detailed molecular mechanism occurring behind it has yet to be elucidated. The aim of present study was to investigate the underlying detailed pathway of the testicular apoptosis induced by free radical load and redox imbalance due to 2.45 GHz MW radiation exposure and the degree of severity along with the increased exposure duration. Twelve-week old male mice were exposed to 2.45 GHz MW radiation [continuous-wave (CW) with overall average Power density of 0.0248 mW/cm² and overall average whole body SAR value of 0.0146 W/kg] for 2 hr/day over a period of 15, 30, and 60 days. Testicular histology, serum testosterone, ROS, NO, MDA level, activity of antioxidant enzymes, expression of pro-apoptotic proteins (p53 and Bax), anti-apoptotic proteins (Bcl-2 and Bcl-x_L ), cytochrome-c, inactive/active caspase-3, and uncleaved PARP-1 were evaluated. Findings suggest that 2.45 GHz MW radiation exposure induced testicular redox imbalance not only leads to enhanced testicular apoptosis via p53 dependent Bax-caspase-3 mediated pathway, but also increases the degree of apoptotic severity in a duration dependent manner.

Comparative effect of melatonin and quercetin in counteracting LPS induced oxidative stress in bone marrow mononuclear cells and spleen of Funambulus pennanti

A majority of cellular diseases, independent of their origin, are characterized by a dramatic increase in Reactive Oxygen Species (ROS) in response to stress. In most cases, the uncontrolled detrimental ROS outburst is difficult to handle for the cellular machinery and eventually leads to cell mortality. In this study, we compare the antioxidant efficacy of quercetin and melatonin to find out a better alternative against lipopolysaccharide (LPS) induced tissue injury by oxidative stress in Funambulus pennanti. Transient exposure to LPS significantly increased ROS generation and lipid peroxidation levels in bone marrow mononuclear cells (MNCs) and spleen which was further corroborated by decreased activities of SOD, CAT and Gpx enzymes. It also downregulate the expression of cellular oxidative stress response proteins Nrf-2 and HO-1 in spleen and decreases the proliferation of bone marrow derived Granulocyte macrophage-colony forming unit cells (GM-CFU). Both melatonin and quercetin pre-treatments rescued these effects, however, our results indicated that the efficacy of melatonin to overcome oxidative stress was significantly better than quercetin. Our findings support the idea that melatonin is a better antioxidant and immunomodulator as compared to other alternatives and perhaps may be employed in the development of effective therapeutics against ROS dominated diseases.

Antioxidant and Antiapoptotic effect of aqueous extract of Pueraria tuberosa (Roxb. Ex Willd.) DC. On streptozotocin-induced diabetic nephropathy in rats

BACKGROUND

Oxidative stress and renal apoptosis play a significant role in the progression of diabetic nephropathy. The tubers of Pueraria tuberosa (Roxb. ex Willd.) DC. has been traditionally used as anti-ageing and health promotive tonic. The purpose of this study was to investigate its nephroprotective effect and mechanism via antioxidant and antiapoptotic potential in Streptozotocin-induced diabetic nephropathy (DN) in rats.

METHODS

The chemical composition of aqueous extract of Pueraria tuberosa (PTY-2r) was analyzed by gas chromatography-mass spectrometry (GC-MS). Diabetes was induced by intraperitoneal injection of streptozotocin (STZ) (55 mg/kg body weight) in rats. After 60 days, the rats were randomly divided into 3 groups (n = 6/each group), namely DN control (DN) group-2, DN rats treated with PTY-2r at the dose of 50 mg/100 g, group-3 and 100 mg/100 g, group-4 p.o. for 20 days. The normal rats were chosen as a normal control (NC) group-1. PTY-2r was orally given to the rats for 20 days. Reactive oxygen species (ROS), lipid peroxidation (LPO) and the activity of ROS-scavenging enzymes - superoxide dismutase (SOD), catalase (CAT) & glutathione peroxidase (GPx) were determined in the kidney tissue of DN rats. The expression of apoptosis-related proteins was measured by immunofluorescence.

RESULTS

GC-MS analysis of PTY-2r indicated the presence of 37 compounds among them 5-Hydroxymethylfurfural (17.80%), 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (17.03%), n-Hexadecanoic acid (5.18%) and 9-Octadecenoic acid (Z) - (6.69%) were found in the higher amount. A significant increase in ROS and LPO was observed along with the decreased activity of antioxidant enzymes, responsible for oxidative stress in the kidney of DN rats. Since, high oxidative stress induces apoptosis in target cells, as shown by significantly decreased expression of Bcl-2 along with increased expression of Bax, active Caspase-3 & cleaved PARP-1 in DN control rats, suggesting apoptosis. The PTY-2r treatment significantly raised the activity of antioxidant enzymes, suppressed oxidative stress and apoptosis thus, prevented urinary albumin excretion in a dose-dependent manner.

CONCLUSIONS

The findings suggest that PTY-2r exerted the nephroprotective potential against STZ induced DN rats via suppressing oxidative stress and apoptosis due to the presence of different bioactive compounds. ᅟ.

Attenuating Effect of Zinc and Vitamin E on the Intestinal Oxidative Stress Induced by Silver Nanoparticles in Broiler Chickens

Silver nanoparticles (AgNPs) have been increasingly used as antimicrobial and disinfectant. However, intestinal model studies have shown that AgNPs induce oxidative stress. Hence, this study aims to investigate the effects of dietary supplemental zinc (Zn) and vitamin E (VE; α-tocopherol acetate) on attenuating AgNP-induced intestinal oxidative stress in broiler chickens. The chickens were divided into two groups as follows: (1) control group fed with a corn-soybean meal basal diet and (2) nano group, received drinking water containing 1000 mg/kg AgNPs. All the nano-exposed birds were divided into six dietary treatment groups, namely, the basal diets supplemented with (1) 60 mg/kg Zn as ZnSO₄, (2) 120 mg/kg Zn, (3) 100 mg/kg VE, (4) 200 mg/kg VE, (5) 60 mg/kg Zn and 100 mg/kg VE, and (6) 120 mg/kg Zn and 200 mg/kg VE. Results showed that the AgNPs significantly reduced the body weights of the broilers after 42 days of oral administration of AgNPs (P < 0.05), and this effect was not alleviated by any of the dietary treatments. The activity of superoxide dismutase (CuZn-SOD) increased in all the AgNP-treated birds (P < 0.05); however, CuZn-SOD did not increase in birds fed with basal diet supplemented with 200 mg/kg VE. In this treatment, the VE exerted an antioxidant effect to prevent the activation of the CuZn-SOD enzyme. Furthermore, supplementing Zn increased the activities of catalase and glutathione peroxidase in the jejunal mucosa (P < 0.05), which were accompanied with increased malondialdehyde levels (P < 0.05) in the broilers. AgNP exposure resulted in a significant messenger RNA (mRNA) upregulation of toll-like receptor 4 (TLR4) and TLR2-1 in the jejunal mucosa (P < 0.05). However, supplemental ZnVE did not reduce TLRs' mRNA expression, except for the diminished TLR2-1 mRNA levels in birds fed with basal diet supplemented with 120 mg/kg Zn and 200 mg/kg VE. We concluded that although dietary Zn and VE supplementation did not attenuate growth depression effect of AgNP, it however attenuates intestinal oxidative stress in AgNP-treated broiler chickens.

Mobile phone (1800MHz) radiation impairs female reproduction in mice, Mus musculus, through stress induced inhibition of ovarian and uterine activity

Present study investigated the long-term effects of mobile phone (1800MHz) radiation in stand-by, dialing and receiving modes on the female reproductive function (ovarian and uterine histo-architecture, and steroidogenesis) and stress responses (oxidative and nitrosative stress). We observed that mobile phone radiation induces significant elevation in ROS, NO, lipid peroxidation, total carbonyl content and serum corticosterone coupled with significant decrease in antioxidant enzymes in hypothalamus, ovary and uterus of mice. Compared to control group, exposed mice exhibited reduced number of developing and mature follicles as well as corpus lutea. Significantly decreased serum levels of pituitary gonadotrophins (LH, FSH), sex steroids (E2 and P4) and expression of SF-1, StAR, P-450scc, 3β-HSD, 17β-HSD, cytochrome P-450 aromatase, ER-α and ER-β were observed in all the exposed groups of mice, compared to control. These findings suggest that mobile phone radiation induces oxidative and nitrosative stress, which affects the reproductive performance of female mice.

Lack of XPC leads to a shift between respiratory complexes I and II but sensitizes cells to mitochondrial stress

Genomic instability drives tumorigenesis and DNA repair defects are associated with elevated cancer. Metabolic alterations are also observed during tumorigenesis, although a causal relationship between these has not been clearly established. Xeroderma pigmentosum (XP) is a DNA repair disease characterized by early cancer. Cells with reduced expression of the XPC protein display a metabolic shift from OXPHOS to glycolysis, which was linked to accumulation of nuclear DNA damage and oxidants generation via NOX-1. Using XP-C cells, we show that mitochondrial respiratory complex I (CI) is impaired in the absence of XPC, while complex II (CII) is upregulated in XP-C cells. The CI/CII metabolic shift was dependent on XPC, as XPC complementation reverted the phenotype. We demonstrate that mitochondria are the primary source of H₂O₂ and glutathione peroxidase activity is compromised. Moreover, mtDNA is irreversibly damaged and accumulates deletions. XP-C cells were more sensitive to the mitochondrial inhibitor antimycin A, an effect also prevented in XPC-corrected cells. Our results show that XPC deficiency leads to alterations in mitochondrial redox balance with a CI/CII shift as a possible adaptation to lower CI activity, but at the cost of sensitizing XP-C cells to mitochondrial oxidative stress.

Caloric restriction increases brain mitochondrial calcium retention capacity and protects against excitotoxicity

Caloric restriction (CR) protects against many cerebral pathological conditions that are associated with excitotoxic damage and calcium overload, although the mechanisms are still poorly understood. Here we show that CR strongly protects against excitotoxic insults in vitro and in vivo in a manner associated with significant changes in mitochondrial function. CR increases electron transport chain activity, enhances antioxidant defenses, and favors mitochondrial calcium retention capacity in the brain. These changes are accompanied by a decrease in cyclophilin D activity and acetylation and an increase in Sirt3 expression. This suggests that Sirt3-mediated deacetylation and inhibition of cyclophilin D in CR promote the inhibition of mitochondrial permeability transition, resulting in enhanced mitochondrial calcium retention. Altogether, our results indicate that enhanced mitochondrial calcium retention capacity underlies the beneficial effects of CR against excitotoxic conditions. This protection may explain the many beneficial effects of CR in the aging brain.

Supplementation of corn seed with regular diet modulates immune function and antioxidant status in Capra hircus

Melatonin modulates the functional activation of antioxidative enzymes to maintain the oxidant-antioxidant balance in the physiological system. Melatonin administration via subcutaneous injection increases endogenous melatonin concentration that has been used to modulate the immune function in rodents and reproductive activity in small ruminant like goats. However, to date, no report exist which could suggest the effect of corn seed supplementation on the endogenous melatonin concentration and its impact on cellular-immune function and antioxidative enzymes activity in any small ruminant like goats. Therefore, in this study, Zea mays (corn seeds), as source of melatonin, were supplemented with regular diet to explore its impact on endogenous melatonin concentration in goat, Capra hircus. Zea mays supplementation with regular diet for 40 days significantly elevated the endogenous melatonin concentration, proliferative response of peripheral blood mononuclear cells and antioxidative enzymes activity along with total antioxidant capacity of the plasma. An increase in circulatory IL-2 and IL-6 level along with declined TNF-α, malondialdehyde and nitric oxide was noted with elevated endogenous melatonin concentration. In conclusion, it might be suggested that corn seed could be used as supplement to modulate endogenous melatonin concentration that may improve cellular-immune function and antioxidant status. The corn seed might also be included as nutraceutical in regular diet to maintain immune-antioxidant homoeostasis in other species.

Hyperglycemia and high nitric oxide level induced oxidative stress in the brain and molecular alteration in the neurons and glial cells of laboratory mouse, Mus musculus

Chronic hyperglycemia (glucotoxicity) is reported to have detrimental effects on various brain functions leading to neurodegenerative changes. However, the effect of hyperglycemia in combination with high nitric oxide (NO) level (reported to be increased during glucotoxicity), on brain functions is not clear yet. The present study was designed to investigate the effects of hyperglycemic drug Streptozotocin (STZ) and NO donor Sodium nitroprusside (SNP) on the brain of laboratory mouse, Mus musculus. Effects of these conditions were studied on the markers of oxidative stress, NF-κB signalling and the markers of neuronal and glial cell activation/inflammation. Results indicate increased level of MDA and altered antioxidant enzymes activity in both the treated groups compared to control but high levels of AGEs, AOPP and AR activity (markers of diabetic complications) were observed in STZ group only. On the other hand, while STZ group showed decreased IL-6 level, it was increased in SNP group but IFN-ϒ level increased in both the treated groups compared to control. Further, in addition to alterations in the expressions of iNOS, IKKβ, IKBα and NF-κB subunits (RelA-p65/RelB-p50) observed in the neurons and glial cells of different brain regions (hypothalamus, basolateral amygdala and cerebral cortex), enhanced expression of microglial CD11b and astrocytic GFAP was also found in both the treated groups compared to control. Present findings led us to conclude that both hyperglycemia and high NO level causes oxidative stress in addition to molecular alteration in the neurons and glial cells. It is suggested that high blood glucose and NO level induced oxidative stress may lead to neuroinflammation possibly via NF-κB signalling.

Triheptanoin: long-term effects in the very long-chain acyl-CoA dehydrogenase-deficient mouse

A rather new approach in the treatment of long-chain fatty acid oxidation disorders is represented by triheptanoin, a triglyceride with three medium-odd-chain heptanoic acids (C7), due to its anaplerotic potential. We here investigate the effects of a 1-year triheptanoin-based diet on the clinical phenotype of very long-chain-acyl-CoA-dehydrogenase-deficient (VLCAD^-/-) mice. The cardiac function was assessed in VLCAD^-/- mice by in vivo MRI. Metabolic adaptations were identified by the expression of genes regulating energy metabolism and anaplerotic processes using real-time PCR, and the results were correlated with the measurement of the glycolytic enzymes pyruvate dehydrogenase and pyruvate kinase. Finally, the intrahepatic lipid accumulation and oxidative stress in response to the long-term triheptanoin diet were assessed. Triheptanoin was not able to prevent the development of systolic dysfunction in VLCAD^-/- mice despite an upregulation of cardiac glucose oxidation. Strikingly, the anaplerotic effects of triheptanoin were restricted to the liver. Despite this, the hepatic lipic content was increased upon triheptanoin supplementation. Our data demonstrate that the concept of anaplerosis does not apply to all tissues equally.

Melatonin alleviates hyperthyroidism induced oxidative stress and neuronal cell death in hippocampus of aged female golden hamster, Mesocricetus auratus

Oxidative stress is a well known phenomenon under hyperthyroid condition that induces various physiological and neural problems with a higher prevalence in females. We, therefore investigated the antioxidant potential of melatonin (Mel) on hyperthyroidism-induced oxidative stress and neuronal cell death in the hippocampus region of brain (cognition and memory centre) of aged female golden hamster, Mesocricetus auratus. Aged female hamsters were randomly divided into four experimental groups (n=7); group-I: control, group-II: Melatonin (5mgkg(-1)day(-1), i.p., for one week), group-III: Hyperthyroid (100μg kg(-1)day(-1), i.p., for two weeks) and group-IV- Hyper+Mel. Hormonal profiles (thyroid and melatonin), activity of antioxidant enzymes (SOD, CAT and GPX), lipid peroxidation level (TBARS) and the specific apoptotic markers (Bax/Bcl-2 ratio and Caspase-3) expression were evaluated. A significant increase in the profile of total thyroid hormone (tT3 and tT4) in hyperthyroidic group as compared to control while tT3 significantly decreased in melatonin treated hyperthyroidic group. However, Mel level significantly decreased in hyperthyroidic group but increased in melatonin treated hyperthyroidic group. Further, the number of immune-positive cells for thyroid hormone receptor-alpha (TR-α) decreased in the hippocampus of hyperthyroidic group and increased in melatonin treated hyperthyroidic group. Profiles of antioxidant enzymes showed a significant decrease in hyperthyroidic group with a simultaneous increase in lipid peroxidation (TBARS). Melatonin treatment to hyperthyroidic group lead to decreased TBARS level with a concomitant increase in antioxidant enzyme activity. Moreover, increased expression of Bax/Bcl-2 ratio and Caspase-3, in hyperthyroidic group had elevated neuronal cell death in hippocampal area and melatonin treatment reduced its expression in hyperthyroidic group. Our findings thus indicate that melatonin reduced the hyperthyroidism-induced oxidative stress and neuronal cell death in the hippocampus region of brain, suggesting a novel therapeutic approach of melatonin for management of cognition and memory function in females under hyperthyroid condition.

Effects of Flaxseed Oil on Serum Lipids and Atherosclerosis in Hypercholesterolemic Rabbits

Objective: Flaxseed oil has very high content of ox-linolenic acid (C18:3n-3, omega-3 [n-3] fatty acid). Based on the usefulness of n-3 fatty acid in fish oil against cardiovascular diseases, flaxseed oil is marketed as a health food. The n-3 fatty acid in flaxseed oil is different than that of fish oil. Indirect evidence suggests that the omega-3 fatty acid in flaxseed oil is not effective in lowering serum lipids and hypercholesterolemic atherosclerosis. The effects of flaxseed oil on serum lipids and hypercholesterolemic atherosclerosis are not known. An investigation, therefore, was made of flaxseed oil on high-cholesterol diet-induced atherosclerosis, serum lipids (triglycerides, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, risk ratio of total cholesterol to high-density lipoprotein cholesterol), serum and aortic malondialdehyde, an index of levels of reactive oxygen species, aortic chemiluminescence (a measure of antioxidant reserve), and reactive oxygen species-producing activity of white blood cell chemiluminescence in rabbits.

Methods: The rabbits were assigned to four groups: Group I, regular diet (control); Group II, 5% flaxseed oil in regular diet; Group III, 0.5% cholesterol diet; Group IV, diet containing 0.5% cholesterol and 5% flaxseed oil. Blood samples were collected before and after 4 and 8 weeks of experimental diets for measurement of serum lipids, serum malondialdehyde, and white blood cell chemiluminescence. At the end of 8 weeks of the experimental diet, aortas were removed for measurement of atherosclerotic plaques, aortic malondialdehyde, and antioxidant reserve.

Results: Serum total cholesterol, triglycerides, and low-density and high-density lipoprotein cholesterol, and risk ratio of total cholesterol to high-density lipoprotein cholesterol, were elevated to a similar extent in Groups III and IV compared to Groups I and II. The extent of atherosclerosis in Groups III and IV was similar (56.74% ± 11.14% vs 58.01% ± 10.95%). Groups III and IV both had similar increases in serum and aortic malondialdehyde and antioxidant reserve. Reactive oxygen species-producing activity of white blood cells increased in Group III, and flaxseed oil prevented the cholesterol-induced increase in white blood cell chemiluminescence in Group IV.

Conclusion: These results suggest that flaxseed oil does not produce an alteration in serum lipids or in the extent of hypercholesterolemic atherosclerosis; however, it decreases white blood cell chemiluminescence. The ineffectiveness of flaxseed oil was associated with its ineffectiveness in altering the levels of oxidative stress.

A Study on Regression of Hypercholesterolemic Atherosclerosis in Rabbits by Flax Lignan Complex

Flax lignan complex (FLC) isolated from flaxseed suppresses the development of hypercholesterolemic atherosclerosis. The objectives of this study were to investigate if FLC produces regression of atherosclerosis and if regression is associated with reductions in serum lipids and oxidative stress. The studies were conducted in 4 groups of rabbits: group I, control diet (2 months); group II, 0.25% cholesterol diet (2 months); group III, 0.25% cholesterol diet (2 months) followed by regular diet (4 months); and group IV, 0.25% cholesterol diet (2 months) followed by regular diet and FLC (4 months). Serum lipids and oxidative stress parameters were measured before and at various intervals thereafter on their respective diets. The aortas were removed at the end of the protocol for assessment of atherosclerotic plaques and oxidative parameters. Atherosclerosis in group II was associated with hyperlipidemia and increased oxidative stress. Atherosclerotic changes were accelerated in group III, and this was associated with reductions in serum lipids and oxidative stress. Atherosclerotic lesions in group IV were similar to group II, but significantly smaller than those in group III, and were associated with reductions in serum lipids and oxidative stress similar to that in group III. These results indicate that FLC does not produce regression but prevents the acceleration of atherosclerosis due to the removal of cholesterol in the diet. These effects of FLC are not associated with reductions in serum lipids and oxidative stress.

Sulforaphane attenuates the development of atherosclerosis and improves endothelial dysfunction in hypercholesterolemic rabbits

The aim of the present work was to explore possible protective effects of sulforaphane (SFN) against atherosclerosis development and endothelial dysfunction in hypercholesterolemic rabbits. Rabbits were assigned to three groups of five: group I fed normal chow diet for four weeks, group II fed 1% high cholesterol diet (HCD) and group III fed HCD + SFN (0.25 mg/kg/day). Blood samples were collected for measurement of serum triglycerides (TGs), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), lactate dehydrogenase (LDH) and C-reactive protein (CRP). Aortic malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD) and total nitrite/nitrate (NOx) were measured. Vascular reactivity and intima/media (I/M) ratio were analyzed. Nuclear factor-kappa B (NF-κB) activation in aortic endothelial cells was identified immunohistochemically. HCD induced significant increases in serum TGs, TC, LDL-C, LDH, and CRP, and aortic MDA and SOD. Moreover, HCD caused significant reductions in serum HDL-C, aortic GSH and NOx. SFN administration significantly decreased HCD-induced elevations in serum TC, LDL-C, CRP, and LDH. while significantly increased HDL-C and GSH levels and normalized aortic SOD and NOx. Additionally, SFN significantly improved rabbit aortic endothelium-dependent relaxation to acetylcholine. Moreover, SFN significantly reduced the elevation in I/M ratio. This effect was confirmed by aortic histopathologic examination. The expression of NF-κB in aortic tissue showed a marked reduction upon treatment with SFN. In conclusion, this study reveals that SFN has the ability to ameliorate HCD-induced atherosclerotic lesions progression and vascular dysfunction, possibly via its lipid-lowering and antioxidant effects and suppression of NF-κB-mediated inflammation.

Effects of fish oil and spirulina on oxidative stress and inflammation in hypercholesterolemic hamsters

Background

Altered plasma lipids, oxidative stress, and inflammation have been involved in the pathogenesis of cardiovascular disease. Fish oil has shown inconclusive effects on plasma lipids and oxidative stress. Spirulina has both cholesterol lowering and antioxidant properties. However, the effect of fish oil and spirulina on hypercholesterolemia has not been studied. We investigated the effects of fish oil, spirulina, and their combination on hypercholesterolemia.

Methods

The hamsters were divided into 7 groups: control, high cholesterol (HF), fish oil (post FO), spirulina (post SP), and a combination of fish oil and spirulina (post SF, pre-SF, and HF + SF) groups. The HF and HF + SF groups were given a high cholesterol diet for 8 weeks. The post FO, post SP, and post SF groups were given a high cholesterol diet for 4 weeks and then the treatment for 4 weeks. The pre-SF group was given the combined treatment for 4 weeks and then a high cholesterol diet for 4 weeks.

Results

The HF and HF + SF groups altered plasma lipids, increased oxidative stress, inhibited antioxidants, and increased inflammation. While the post FO group increased plasma lipids and was more atherogenic. The vice versa was observed in spirulina-treated group. Both the post SP and post SF groups inhibited oxidative stress and increased antioxidant status, and post FO and post SP diets regulated pro-inflammatory cytokines to near the control levels.

Conclusions

Both single treatment of fish oil or spirulina inhibit oxidative stress and inflammation. Treatment with a combination of fish oil and spirulina (post SF) may be beneficial for diet-induced hypercholesterolemic hamsters.

Curcumin-Protected PC12 Cells Against Glutamate-Induced Oxidative Toxicity

Glutamate is a major excitatory neurotransmitter present in the central nervous system. The glutamate/cystine antiporter system x c- connects the antioxidant defense with neurotransmission and behaviour. Overactivation of ionotropic glutamate receptors induces neuronal death, a pathway called excitotoxicity. Glutamate-induced oxidative stress is a major contributor to neurodegenerative diseases including cerebral ischemia, Alzheimer's and Huntington's disease. Curcuma has a wide spectrum of biological activities regarding neuroprotection and neurocognition. By reducing the oxidative damage, curcumin attenuates a spinal cord ischemia-reperfusion injury, seizures and hippocampal neuronal loss. The rat pheochromocytoma (PC12) cell line exhibits many characteristics useful for the study of the neuroprotection and neurocognition. This investigation was carried out to determine whether the neuroprotective effects of curcumin can be observed via the glutamate-PC12 cell model. Results indicate that glutamate (20 mM) upregulated glutathione peroxidase 1, glutathione disulphide, Ca2+ influx, nitric oxide production, cytochrome c release, Bax/Bcl-2 ratio, caspase-3 activity, lactate dehydrogenase release, reactive oxygen species, H 2 O 2 , and malondialdehyde; and downregulated glutathione, glutathione reductase, superoxide dismutase and catalase, resulting in enhanced cell apoptosis. Curcumin alleviates all these adverse effects. Conclusively, curcumin can effectively protect PC12 cells against the glutamate-induced oxidative toxicity. Its mode of action involves two pathways: the glutathione-dependent nitric oxide-reactive oxygen species pathway and the mitochondria-dependent nitric oxide-reactive oxygen species pathway.

UVB irradiation severely induces systemic tissue injury by augmenting oxidative load in a tropical rodent: efficacy of melatonin as an antioxidant

Tropical animals are regularly exposed to solar UV radiation. The generation and accumulation of free radicals as a result of UVB incidence causes tissue damage. In the present study we report that the irradiation of Funambulus pennanti by 1.5 J/cm(2) of UVB caused significant oxidative damage to the spleen. The systemic immunity suffered collateral damage as depicted by results of total leukocyte count (TLC) while an increase in the thiobarbituric acid reactive substances (TBARS) and decline in the activities of enzymes superoxide dismutase (SOD), Glutathione peroxidase (GSH-Px) and Catalase (CAT) denoted oxidative tissue damage. Melatonin the indole-amine with known antioxidative properties when administered subcutaneously (s.c 100 μg/100 gm body weight), before the UVB irradiation recovered the damages caused by UVB radiation in the spleen. The action of melatonin was direct and might have involved its membrane receptor (MT1) as well as nuclear receptor (RORα) indicating the fact that the mode of action of melatonin in ameliorating UVB radiation induced free radical load may be receptor mediated. Our study hence reports for the first time that UVB radiation incurred oxidative damage to the spleen and suppressed the normal tissue functions. This UVB mitigated oxidative stress was recovered by the free radical scavenging and anti-apoptotic functions of melatonin when administered prior to UVB irradiation.

Renal response to short- and long-term exercise in very-long-chain acyl-CoA dehydrogenase-deficient (VLCAD(-/-)) mice

BACKGROUND

Deficiency of very long-chain acyl-CoA dehydrogenase (VLCAD) is the most common disorder of mitochondrial β-oxidation of long-chain fatty acids. In order to maintain glucose homeostasis, the kidney and liver as the main gluconeogenic organs play an important role under conditions of impaired fatty acid oxidation. However, little is known about how a defective fatty acid oxidation machinery affects renal metabolism and function as well as renal energy supply especially during catabolic situations.

METHODS

In this study, we analyzed VLCAD(-/-) mice under different metabolic conditions such as after moderate (1 h) and intensive long-term (1 h twice per day over 2 weeks) physical exercise and after 24 h of fasting. We measured the oxidation rate of palmitoyl-CoA (C16-CoA) as well as the expression of genes involved in lipogenesis and renal failure. Oxidative stress was assessed by the function of antioxidant enzymes. Moreover, we quantified the content of glycogen and long-chain acylcarnitines in the kidney.

RESULTS

We observed a significant depletion in renal glycogen with a concomitant reduction in long-chain acylcarnitines, suggesting a substrate switch for energy production and an optimal compensation of impaired fatty acid oxidation in the kidney. In fact, the mutants did not show any signs of oxidative stress or renal failure under catabolic conditions.

CONCLUSIONS

Our data demonstrate that despite Acadvl ablation, the kidney of VLCAD(-/-) mice fully compensates for impaired fatty acid oxidation by enhanced glycogen utilization and preserves renal energy metabolism and function.

Vitamin E and regression of hypercholesterolemia-induced oxidative stress in kidney

Hypercholesterolemia (HC) is an independent risk factor for the onset and progression of renal disease. HC induces oxidative stress (OS) in the kidney; Vitamin E (Vit.E), an antioxidant, slows the progression of OS in the kidney. This study was to investigate if Vit.E regresses the HC-induced OS, and the regression is associated with an increase in the antioxidant reserve (AR). The studies were carried out in four groups of rabbits. The kidneys were removed under anesthesia. OS and AR in the renal tissue were assessed by measuring malondialdetyde (MDA) and chemiluminescent (CL) activity, respectively. High-cholesterol diet elevated the serum total cholesterol (TC), and the regular diet with or without Vit.E following a high-cholesterol diet reduced the serum TC to control levels. HC increased the MDA levels of kidney by 5.54-fold compared to control. The MDA contents of the kidneys in groups on regular diet with or without Vit.E were, respectively, 56 and 53 % lower than the control group. The CL activity in the control group was 12.15 ± 0.73 × 10(6) RLU/mg protein. The CL activity in HC group was 45.26 % lower than that in control, indicating an increase in AR. The regular diet with or without Vit.E following high-cholesterol diet normalized the CL activity/AR. In conclusion, HC increases OS in the kidney; reduction of serum cholesterol by regular diet regresses the renal OS but Vit.E does not regress HC-induced OS in kidney.

Acute toxicity and the effect of andrographolide on Porphyromonas gingivalis-induced hyperlipidemia in rats

The aim of the current study is to evaluate the effect of andrographolide on hyperlipidemia induced by Porphyromonas gingivalis in rats. Thirty male Sprague Dawley (SD) rats were divided into five groups as follows: group 1 (vehicle) and four experimental groups (groups 2, 3, 4, and 5) were challenged orally with P. gingivalis ATCC 33277 (0.2 mL of 1.5 ×10(12) bacterial cells/mL in 2% carboxymethylcellulose (CMC) with phosphate-buffered saline (PBS)) five times a week for one month to induce hyperlipidemia. Then, group 3 received a standard oral treatment with simvastatin 100 mg/kg, and groups 4 and 5 received oral treatment with andrographolide 20 mg/kg and 10 mg/kg, respectively, for another month. The results showed that total cholesterol (TC), low-density lipoprotein (LDL-C), and triglycerides (TG) were reduced significantly in groups treated with andrographolide. The malondialdehyde (MDA) level was low in treated groups, while antioxidant enzymes, superoxide dismutase (SOD), and glutathione peroxidase (GPx) were significantly increased in these groups (P < 0.05). Liver tissues of the groups treated with andrographolide reduce the accumulation of lipid droplets in hepatic tissue cells. An acute toxicity test did not show any toxicological symptoms in rats.

2.45 GHz microwave irradiation-induced oxidative stress affects implantation or pregnancy in mice, Mus musculus

The present experiment was designed to study the 2.45 GHz low-level microwave (MW) irradiation-induced stress response and its effect on implantation or pregnancy in female mice. Twelve-week-old mice were exposed to MW radiation (continuous wave for 2 h/day for 45 days, frequency 2.45 GHz, power density=0.033549 mW/cm(2), and specific absorption rate=0.023023 W/kg). At the end of a total of 45 days of exposure, mice were sacrificed, implantation sites were monitored, blood was processed to study stress parameters (hemoglobin, RBC and WBC count, and neutrophil/lymphocyte (N/L) ratio), the brain was processed for comet assay, and plasma was used for nitric oxide (NO), progesterone and estradiol estimation. Reactive oxygen species (ROS) and the activities of ROS-scavenging enzymes- superoxide dismutase, catalase, and glutathione peroxidase-were determined in the liver, kidney and ovary. We observed that implantation sites were affected significantly in MW-irradiated mice as compared to control. Further, in addition to a significant increase in ROS, hemoglobin (p<0.001), RBC and WBC counts (p<0.001), N/L ratio (p<0.01), DNA damage (p<0.001) in brain cells, and plasma estradiol concentration (p<0.05), a significant decrease was observed in NO level (p<0.05) and antioxidant enzyme activities of MW-exposed mice. Our findings led us to conclude that a low level of MW irradiation-induced oxidative stress not only suppresses implantation, but it may also lead to deformity of the embryo in case pregnancy continues. We also suggest that MW radiation-induced oxidative stress by increasing ROS production in the body may lead to DNA strand breakage in the brain cells and implantation failure/resorption or abnormal pregnancy in mice.

Improvement of oxidative stress and immunity by melatonin: an age dependent study in golden hamster

Reactive oxygen species (ROS) have been proposed to play an important role in balancing the pro- and antioxidant homeostasis during aging. Melatonin has been suggested as an effective free radical scavenger that might have a role during the process of aging. We observed, that melatonin administration (25 μg/100 g body weight for 30 days) significantly augments the activity of anti-oxidative enzymes like superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) in the plasma, spleen and bone marrow (BM) of young (6 weeks), adult (30 weeks) and old aged (2.5 years) male golden hamster, Mesocricetus auratus. A sharp decline in generation of ROS was observed in peripheral blood mononuclear cells (PBMC) and splenocytes upon melatonin administration in different age group of hamsters. Reduction in the level of thiobarbituric acid-reactive substances (TBARS) and total nitrite and nitrate concentration as metabolites and indicators of nitric oxide (NO) in plasma, spleen and BM were observed along with night time (22:00 h) melatonin concentration in different age group of hamsters after administration of melatonin and compared to the control group (treated with 0.9% saline). General immune parameters like proliferation of splenocytes, PBMC and colony forming ability of GM-CFU were observed following melatonin treatment in different age group, although it was low only in aged hamsters compared to the young and adult. Our data indicates that the age related increase of oxidative load and simultaneously augments the general immunity in aged hamsters.

Different responses of fluvastatin to cholesterol-induced oxidative modifications in rabbits: evidence for preventive effect against DNA damage

Hypercholesterolemia is a major risk factor for atherosclerosis and related occlusive vascular diseases. We investigated the effect of low-dose fluvastatin (2 mg kg(-1) day(-1)) on antioxidant enzyme activities [superoxide dismutase (SOD), catalase], vascular reactivity changes and oxidatively induced DNA damage in early stage of atherosclerosis in hypercholesterolemic rabbits. The animals were divided into three groups each composed of 10 rabbits. The control group received a regular rabbit chow diet, and the cholesterol group had hypercholesterolemic diet (2%, 4 weeks). The fluvastatin group was given hypercholesterolemic diet plus fluvastatin. Dietary intake of cholesterol significantly increased total cholesterol levels in rabbits (control, 0.85 ± 0.29; cholesterol, 12.04 ± 4.61; fluvastatin, 8.07 ± 2.72 mmol l(-1)). Hypercholesterolemic diet revealed discernible fatty streaks in arcus aortae. Fluvastatin significantly reduced the areas of the lesions. The diet significantly increased SOD activities in both erythrocyte and tissue. Treatment with fluvastatin normalized the increased activity of SOD in both erythrocyte and aortic tissues from the cholesterol group. Cholesterol feeding decreased the sensitivity to acetylcholine, and treatment with fluvastatin significantly restored the diminished sensitivity to acetylcholine in thoracic aortae. Cholesterol feeding caused oxidatively induced DNA damage in liver tissues determined by the increased levels of 8-hydroxyguanine (8-OH-Gua) and 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyGua). Fluvastatin decreased only FapyGua level in liver. In conclusion, our results may suggest that fluvastatin seems to play a protective role on high cholesterol-induced oxidative stress and DNA damage.

Effect of tea polyphenol on oxidative injury in S180 cells induced hepatocarcinoma mice

The purpose of this study was to evaluate the antioxidant nature of tea polyphenol on S180 cells induced liver cancer in mice. In the present study, hepatocellular carcinoma was induced by tumor transplantation of liver in situ. The antitumor activity of tea polyphenol has been determined in vivo in hepatocellular carcinoma mice after treatment of drug (50, 100, 150 mg/kg body weight) by gavage for 20 days. Results showed that a significant increase in serum aspartate transaminase (AST), alkaline phosphatase (ALP), alanine aminotransfere (ALT), malondialdehyde (MDA) level, decrease in serum white blood cells (WBC), serum total protein (TP), albumin (ALB), A/G, tumor necrosis factor-α (TNF-α) and interferon-gamma (IFN-γ), liver reduced glutathione (GSH) levels were observed. In addition, the levels of enzymic and non-enzymic antioxidants were decreased when subjected to S180 cells induction. These altered enzyme levels were ameliorated significantly by administration of tea polyphenol at the concentration of 50, 100, 150 mg/kg body weight in drug-treated animals. These results indicate that the protective effect of tea polyphenol was associated with inhibition of MDA induced by S180 cells and to maintain the antioxidant enzyme levels.

Low-Dose Fluvastatin Prevents the Functional Alterations of Endothelium Induced by Short-Term Cholesterol Feeding in Rabbit Carotid Artery

3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, commonly known as statins, are the medical treatment of choice for hypercholesterolemia. In addition to lowering serum-cholesterol levels, statins appear to promote pleiotropic effects that are independent of changes in serum cholesterol. In this study, we investigated the effects of low-dose fluvastatin on antioxidant enzyme activities (superoxide dismutase, SOD; catalase), total nitrite/nitrate levels, and vascular reactivity in 2% cholesterol-fed rabbits. This diet did not generate any fatty streak lesions on carotid artery wall. However, SOD activity significantly increased with cholesterol feeding whereas the catalase activities decreased. The levels of nitrite/nitrate, stable products of NO degradation, diminished. Moreover, dietary cholesterol reduced vascular responses to acetylcholine, but contractions to serotonin were augmented. Fluvastatin treatment abrogated the cholesterol-induced increase in SOD, increased the levels of nitric oxide metabolites in tissue, and restored both the impaired vascular responses to acetylcholine and the augmented contractile responses to serotonin without affecting plasma-cholesterol levels. Phenylephrine contractions and nitroglycerine vasodilatations did not change in all groups. This study indicated that fluvastatin treatment performed early enough to improve impaired vascular responses may delay cardiovascular complications associated with several cardiovascular diseases.