Oxidative Stress Enzyme Activities Research Articles

Polyphenolic rich extract of Oroxylum indicum alleviate β-glucuronidase activity via down-regulate oxidative stress: Experimental and computational studies

Oroxilum indicum has an extensive history in the Indian traditional medicine system. The root and stem bark of this plant is well accepted for the treatment, prevention, and cure of various types of diseases. The bark of the plant has a high content of flavonoids and other phenolics, which are known to be responsible for exhibiting various therapeutic effects. The role of O. indicum in liver disease is well known, but until now, the mechanism has not been well studied. In the present study, the stem bark of O. indicum was extracted with ethanol using a hot extraction method and their phyto-chemical analysis was performed. Further, the plant extract was also used to evaluate their role in reducing oxidative stress and β-glucuronidase enzyme activity. The antioxidant study showed that extract has the capability to down-regulate oxidative stress, while β-glucuronidase assay displayed IC50 at 174.36 μg/mL. Additionally, we selected the major polyphenolic phyto-compounds derived from the bark of O. indicum for in silico ADME and docking studies. The ADME study reflected the optimal pharmacokinetic profile of the compounds. However, the docking experiments confirmed that all the selected phyto-compounds have tendency to interact with β-glucuronidase receptor.

Chronic cement dust load induce novel damages in foliage and buds of Malus domestica

Cement industry-derived pollutants appear to play multiple roles in stimulating abiotic stress responses in plants. Cement dust deposition on agriculture fields can affect soils, photosynthesis, transpiration and respiration of plants. Here, we characterised the acute physiological responses of Malus × domestica leaves to different cement dust concentrations. The cement dust was sprinkled over plants daily for 2 months at 10 and 20 g/plant, with 0 g/plant serving as the control. Leaf physiological responses revealed significant increases in oxidative stress and antioxidant enzyme activity levels. Additionally, ascorbic acid, soluble sugar, free amino acid, and pigment levels decreased after exposure to cement dust. Macroscopic morphometric parameters, such as weight, dry matter content, and lengths and widths of leaves and buds, were significantly reduced in the cement-treated groups. A histological analysis of leaves and buds revealed decreased cellular areas, cellular damage, and abridged leaf thickness, while an ion leakage assay confirmed the negative effects on tissue integrity. These results provide evidence that cement dust is a hazardous pollutant that induces abiotic stress responses and has degradative effects on leaf health, pigment and biochemical metabolite levels, and anatomical features. Studies to determine the elemental residues of cement dust present in edible plant parts and the adverse impacts of their consumption on human health are strongly recommended.

Assessment of antioxidant traits and protective action of Egyptian acacia pods extracts against paracetamol-induced liver toxicity in rats.

This study investigates the protective effect of Egyptian acacia pod extracts against overdose of paracetamol-induced liver damage. Egyptian acacia green and brown pods were extracted by mixture of ethanol 80%: HCl (6M) (99:1 v/v). In extracts of green and brown pods, total phenolic content in hydrolyzed ethyl acetate fraction (HEF) at pH 4, was 649.89 and 712.14mg GAE/g while antioxidant activity was 95.55% and 97.35%, both being the highest than any fraction. HEF (pH 4) in brown pods was analyzed by HPLC, there were 22 phenolic compounds rich in ethyl vanillin about 227mg/g and 11 flavonoids rich in catechin 48.70mg/g. A biological experiment was conducted using HEF (pH4) in brown pods against overdose of paracetamol in albino rats induced to hepatotoxicity. Thirty rats were divided into five groups; a control group, a paracetamol group, and the other three received paracetamol plus silymarin or two doses of HEF. Animals were received paracetamol and treated with either silymarin or HEF showed reduced levels of liver (ALT, AST, and ALP) and kidney (urea, creatinine, and uric acid) markers compared with the control group as well as reduction of oxidative stress and increment antioxidant enzyme activity in liver tissue when compared with the paracetamol group. It could be concluded that both HEF and silymarin are considerably high hepatoprotector against paracetamol-induced hepatotoxicity in rats due to their strong antioxidant activity. PRACTICAL APPLICATIONS: Both HEF and silymarin improved liver functions and exerted strong antioxidant activities. This antioxidant activity would have a positive effect against oxidative liver damage caused by parcetamol. Thus, it may be concluded that the liver plasma membranes were protected and the regenerative and reparative capacity of liver by phenolic compound in HEF treatment. The study demonstrated the HEF hepatoprotective activity and recommends using Egyptian acacia pods for treatment of liver disorders.

Evaluation of the biocompatibility of the GSH-coated Ag2S quantum dots in vitro: a perfect example for the non-toxic optical probes

Near-infrared quantum dots (NIR QDs) are promising candidate for the fluorescent probes due to their better penetration depth, long-lived luminescence with size-tunable photoluminescence wavelengths. Glutathione-coated silver sulfide quantum dots (GSH-Ag2S QDs) were synthesized using AgNO3 and Na2S in the aqueous media and they can give reaction with glutathione reductase (GR) and glutathione-s transferase (GST) enzymes as acting substrate analogue in vitro. Investigation of the toxicity of the nanomaterials are necessary to use them in the medical field and biomedical applications. Thus, in this study we investigated biocompatibility of the GSH-Ag2S QDs in vitro using 293T and CFPAC-1 cell lines. Cell viability by MTT assay, light microscopy, fluorescence microscopy, oxidative stress enzyme activities and ICP-MS analysis were performed to evaluate the cytotoxicity and internalization of the GSH-Ag2S QDs. GSH-Ag2S QDs showed great biocompatibility with both cell lines and did not cause imbalance in the oxidative stress metabolism. The ultralow solubility product constant of Ag2S QDs (Ksp = 6.3 × 10-50) prevents release of Ag ions into the biological systems that is in agreement with data obtained by ICP-MS. In conclusion, this data prove potential of GSH-Ag2S QDs as a biocompatible optical probe to be used for the detection and/or targeting of GSH impaired diseases including cancer.

Evaluation of Stress Enzymes Activities and Lipid Peroxidation in Heart Homogenates of Male Albino Rats Following the Administration of Diclofenac

Nonsteroidal anti-inflammatory drugs are associated with an increase in cardiovascular events despite its uses in the therapeutic agent for the management of long- and short-term pain. Over the last years, evidence has accumulated showing that oxidative stress plays an important role in the pathogenesis of cardiovascular diseases. Oxidative stress is no longer considered as a simple imbalance between the production and scavenging of reactive oxygen species (ROS), but as a dysfunction of enzymes involved in ROS production. This study investigated the effect of diclofenac on the activity of oxidative stress enzymes as well as formation of lipid peroxidation. Male rats weighing about 100-120 g were divided into four groups: group one (control, feed+water) group two, group three and group four treated with different mg/kg/day of drugs (50 mg/kg/day, 100 mg/kg/day and 150 mg/kg/day) feed and water respectively for 7 days. Analysis on the effect of diclofenac on the activities of stress enzymes such as nicotine adenosine dinucleotide phosphate hydrogenase oxidase (NADPHoxidase), xanthine oxidase(XOD), catalase(CAT), superoxide dismutase(SOD) and Glutathione Peroxidase as well as evaluation of lipid peroxidation by measuring malondialdehyde (MDA) in the heart homogenate were carried out and the result showed a significant increase in each parameter given rise to the production of reactive oxygen species (ROS) if not moderated by the antioxidant defense can lead to cardiac impairment as a result of oxidative stress damage or injury. The result obtained implies that diclofenac (NSAIDs) affects the redox status of vascular tissues (heart tissues).

Prophylactic effect of resveratrol and piperine on pristane-induced murine model of lupus-like disease.

Systemic lupus erythematosus is a multisystem autoimmune disease. Apart from usual treatments, approximately 50% of lupus patients use complementary medicine. Resveratrol is a phytoalexin with various pharmacological properties. We hypothesised that prophylactic treatment with resveratrol may abrogate manifestations in pristane-induced murine model of lupus-like disease and piperine; a bio-enhancer of resveratrol may enhance these properties. The prophylactic effect of resveratrol (25mg/kg body weight: P-Res) alone and in combination with piperine (2.5mg/kg body weight: P-RP) were assessed. P-Res and P-RP were equally efficient in mitigating oxidative stress (enzyme activity of catalase, superoxide dismutase, glutathione peroxidase and level of reduced glutathione, lipid peroxidation, and reactive oxygen species). Inflammation is associated with an increase in inflammatory cytokines. IL-6 was decreased by 71.60% with P-Res, and TNF-α was reduced by 59.70% with P-Res and 62.66% with P-RP (p < 0.05). Prevention of renal pathologies was evident by reduction in creatinine level by P-RP (p < 0.05) and abrogation of proteinuria (P-Res and P-RP). P-RP was efficient in restoring histopathology of liver and lungs and decreased immune complexes in lungs. P-Res proved more beneficial by extenuating lipogranulomas, histopathological manifestations in kidney, liver, and lungs, and eliminating immune complexes in liver and lungs. None of the treatments could regulate auto-antibody formation. Resveratrol decreases the susceptibility of developing pathogenesis in murine model of lupus-like disease. The results also conclude that addressing the bioavailability of resveratrol using it in combination with piperine does not prove more efficacious in preventing lupus-associated pathologies than resveratrol alone.

Doser les enzymes du stress oxydant, oui ou non ?

The determination of oxidative stress enzymes activities is not easy because the presence of dioxygen in environment and by the production of hydrogen peroxide very unstable. The use of indirect redox systems allows more reliable measures, accurate and right. The interest on these measures remains uncertain because the difficulties related to the interpretation of results. A decrease can reveal a default in antioxidant defenses, or depletion; an increase can signal the response to a stress or to a release by cell lysis. Normal values being in a zone of dubiousness reveal as well incapacity to respond to oxidative stress as the beginning of the response. Thus, a number of observers do not recommend anymore the measure of these enzymes, but only markers of oxidation, vitamins and oligo-elements for antioxidant defense related to dietetic or additional measures.

Involvement of oxidative stress in the sensitivity of two algal species exposed to roxithromycin.

Algal species Raphidocelis subcapitata and Chlorella vulgaris are commonly used to test the chemicals with an antibacterial mode of action during marketing authorization process. However, significant differences in the sensitivity toward antibiotic exposure have been reported. The selection of an inappropriate test species would thus underestimate the environmental hazard of target chemicals and pose a potential threat to the ecosystem. Since oxidative stress is a crucial factor determining the inhibition of algal growth, an investigation on oxidative stress and antioxidant defense mechanisms in these two species was performed to explore its roles in species sensitivity. Here, roxithromycin (ROX), a macrolide antibiotic extensively used to treat respiratory, urinary and soft tissue infections, was used for testing. After 7 days exposure to ROX at the low (0.01 mg L-1) and high (0.09 mg L-1) concentrations, R. subcapitata was inhibited while the growth of C. vulgaris was stimulated. We investigated the roles of oxidative stress in algae by measuring the oxidative stress biomarkers (MDA), non-enzymatic antioxidants (GSH), and antioxidant enzymes (SOD, CAT, GP, GST). The results suggested that when the growth of algae is inhibited, MDA content as well as activities of oxidative stress enzymes would increase, and thus, activating the antioxidant system. On the contrary, it was inferred that when the growth is stimulated, MDA content and oxidative stress enzymes activities would decrease.

Trigonella stellata reduced the deleterious effects of diabetes mellitus through alleviation of oxidative stress, antioxidant- and drug-metabolizing enzymes activities

Ethnopharmacological relevanceGenus Trigonella has a history of folkloric medicinal uses in China, Japan, Egypt and India. There are a variety of therapeutic actions of Trigonella including hypocholesterolemia, hypoglycemia, antibacterial, antiviral, anti-inflammatory activities, antioxidants and appetite stimulant. Aim of the studyThe prevalence of diabetes mellitus is increasing annually. The present study aims at investigating the protective effects of Trigonella stellata against the adverse effects of diabetes mellitus through investigation of the changes in phase I & II drug-metabolizing enzyme activities, protein expression of cytochrome P450 isoenzymes [CYP2E1 & 3A4], oxidative stress, antioxidant enzymes as well as histopathology of both liver and kidney tissues. MethodsGC-MS and MALDI-TOF were used to analyze the main constituents of the aqueous and the ethanolic extract of Trigonella stellata. Western immunoblotting technique used to show the protein expression of CYP450 isozymes in different groups. Spectrophotometric- and fluorophotometric techniques were also used for assessment of different hepatic integrity enzymes. Histopathological techniques used to illustrate the changes in the tissues of both livers and kidneys after different treatments. ResultsTrigonelline was found to be the main constituent of both aqueous and ethanolic extract of Trigonella stellata. Administration of the aqueous and/or the ethanolic extracts of Trigonella stellata to the diabetic rats was found to decrease the blood glucose level, the biochemical markers of both liver (transaminases activities, Lactate dehydrogenase, gamma-glutamyl transferase) and the renal functions (urea, creatinine and bilirubin) which were increased in diabetic-treated rats relative to their normal levels. Diabetes mellitus potentially induced the oxidative stress, and also activities of dimethylnitrosamine N-demethylase I, cytochrome c-reductase, ethoxyresourfin O-deethylase, and the total hepatic content of cytochrome P450. On the other hand, the activity of catalase [CAT], superoxide dismutase [SOD], glutathione S-transferase [GST], glutathione reductase [GR], glutathione peroxidase [GPx] and levels of reduced glutathione [GSH] were potentially inhibited in diabetic rats compared to the control rats. However, treatments of diabetic rats with either aqueous and/or ethanolic extracts of Trigonella stellata restored such changes caused by diabetes almost nearly to their normal levels compared to the control group. Supporting the activity of dimethyl nitrosamine N-demethylase I activity, the protein expression of CYP2E1 was also induced in diabetic rats. However, the aqueous extract of Trigonella stellata was more effective than ethanolic extract in restoring the changes in the protein expression of CYP2E. On the other hand, the protein expression of CYP3A4 was markedly decreased in diabetic rats, and this decrease was partially restored to its normal level after treatment of diabetic rats with aqueous and/or ethanolic extracts. In addition, Trigonella stellata extracts alleviated the histopathological changes in livers and kidneys caused by diabetes mellitus. ConclusionIt is concluded that diabetes mellitus induced changes in oxidative stress, phase I & II drug-metabolizing enzymes, and antioxidant enzymes activities, whereas both extracts of Trigonella stellata alleviated such changes. Alterations in cytochrome P450 system should be considered when therapeutic drugs are administered to diabetic patients since most of xenobiotic are mainly metabolized by this system.

Effects of aerobic and resistance exercise on cardiac remodelling and skeletal muscle oxidative stress of infarcted rats.

We compared the influence of aerobic and resistance exercise on cardiac remodelling, physical capacity and skeletal muscle oxidative stress in rats with MI‐induced heart failure. Three months after MI induction, Wistar rats were divided into four groups: Sham; sedentary MI (S‐MI); aerobic exercised MI (A‐MI); and resistance exercised MI (R‐MI). Exercised rats trained three times a week for 12 weeks on a treadmill or ladder. Statistical analysis was performed by ANOVA or Kruskal‐Wallis test. Functional aerobic capacity was greater in A‐MI and strength gain higher in R‐MI. Echocardiographic parameters did not differ between infarct groups. Reactive oxygen species production, evaluated by fluorescence, was higher in S‐MI than Sham, and lipid hydroperoxide concentration was lower in A‐MI than the other groups. Glutathione peroxidase activity was higher in A‐MI than S‐MI and R‐MI. Superoxide dismutase was lower in S‐MI than Sham and R‐MI. Gastrocnemius cross‐sectional area, satellite cell activation and expression of the ubiquitin‐proteasome system proteins did not differ between groups. In conclusion, aerobic exercise and resistance exercise improve functional capacity and maximum load carrying, respectively, without changing cardiac remodelling in infarcted rats. In the gastrocnemius, infarction increases oxidative stress and changes antioxidant enzyme activities. Aerobic exercise reduces oxidative stress and attenuates superoxide dismutase and glutathione peroxidase changes.

Cross talk: Two way allelopathic interactions between toxic Microcystis and Daphnia

Due to eutrophication, freshwater ecosystems frequently experience cyanobacterial blooms, many of which produce bioactive metabolites that can affect vertebrates and invertebrates life traits. Zooplankton are able to develop tolerance as a physiological response to cyanobacteria and their bioactive compounds, however, this comes with energetic cost that in turn influence Daphnia life traits and may impair populations. Vice versa, it has been suggested that Daphnia are able to reduce cyanobacterial dominance until a certain cyanobacterial density; it remains unclear whether Daphnia metabolites alone influence the physiological state and bioactive metabolites production of cyanobacteria. Hence, this study investigates mutual physiological reactions of toxic Microcystis aeruginosa PCC7806 and Daphnia magna. We hypothesize that a) the presence of D. magna will negatively affect growth, increase stress response and metabolites production in M. aeruginosa PCC7806 and b) the presence of M. aeruginosa PCC7806 will negatively affect physiological responses and life traits in D. magna. In order to test these hypotheses experiments were conducted in a specially designed co-culture chamber that allows exchange of the metabolites without direct contact. A clear mutual impact was evidenced. Cyanobacterial metabolites reduced survival of D. magna and decreased oxidative stress enzyme activity. Simultaneously, presence of D. magna did not affect photosynthetic activity. However, ROS increase and tendencies in cell density decrease were observed on the same day, suggesting possible energy allocation towards anti-oxidative stress enzymes, or other protection mechanisms against Daphnia infochemicals, as the strain managed to recover. Elevated concentration of intracellular and overall extracellular microcystin MC-LR, as well as intracellular concentrations of aerucyclamide A and D in the presence of Daphnia, indicating a potential protective or anti-grazing function. However, more research is needed to confirm these findings.

Histological structure of skeletal muscle in disuse muscle atrophy and role of exercise

Disuse muscle atrophy is one of the most important research topics in fields of rehabilitation and clinical medicine. It refers to morphological and functional alteration of skeletal muscle under the states of hypokinesia, immobilization and weightlessness. This review analyzes a number of structural and functional changes in the skeletal muscle tissue in case of muscle disuse which appeared in loss in the muscle mass, reduction in the transverse diameter of most of muscle fibers, wide spaces between muscle fibers, increase collagen fiber deposition and appearance of apoptotic nuclei in muscle fibers besides sensorial dysfunction such as hypo mechanical responsiveness and diminished contractile function. In addition to the ultrastructural alteration, which include loss of sarcomere organization, indistinguishable A and I bands, irregular distorted Z-line with disruption of myofilaments and fused giant accumulated mitochondria. The review summarizes also the molecular mechanisms of skeletal muscle disuse atrophy which could be resulted from an alteration in the activity of oxidative stress enzymes and lead to increase in protein degradation and/or a reduction in protein synthesis. Moreover, the review discusses the efficiency of potential countermeasures of stretching exercise as a very powerful stimulant of muscle growth and muscle protein synthesis to counteract the structural and functional alterations in muscle tissue caused by disuse. The review showed that stretching exercise can increase the transverse sectional area of muscle fibers, produce a rise in the number of sarcomeres in series and prevent muscle atrophy. Passive stretching also completely prevented the decrease in myonuclear number induced by inactivity. Moreover, stretching accelerated the amelioration of the range of motion limitation and prevent the deposition of connective tissue resulted from disuse muscle atrophy.

Effects of fenclorim on rice physiology, gene transcription and pretilachlor detoxification ability

BackgroundFenclorim (Fen) can effectively protect rice from pretilachlor (Pre) injury, but its effects on rice have not been formally evaluated; thus, the Fen mode of action for alleviating the phytotoxicity caused by Pre in rice is not clear. This study aimed to examine the biochemical and physiological effects of Fen on rice and to determine the changes induced by Fen at the transcriptome level.ResultThe chlorophyll content of rice plants was significantly affected by Pre but not by Fen. The activity of oxidative stress enzymes showed that Fen did not elicit any changes in oxidative stress; however, it reduced lipid peroxidation and oxidative damage induced by Pre. Fen did not affect the uptake of Pre but did affect its persistence in rice. In a transcriptome experiment, Fen upregulated genes in a detoxification pathway. Overall, 25 genes related to detoxification were identified, including P450, GST, and GT. Moreover, qRT-PCR analysis showed that four P450 genes, CYP71Y83, CYP71K14, CYP734A2 and CYP71D55, and two GST genes, GSTU16 and GSTF5, were upregulated by Fen and/or Pre.ConclusionOur work indicates that Fen acts in antioxidative defense in addition to enhancing the metabolism of herbicides in rice.

Enzyme response of activated sludge to a mixture of emerging contaminants in continuous exposure.

The relevant information about the impacts caused by presence of emerging pollutants in mixtures on the ecological environment, especially on the more vulnerable compartments such as activated sludge (AS) is relatively limited. This study investigated the effect of ibuprofen (IBU) and triclosan (TCS), alone and in combination to the performance and enzymatic activity of AS bacterial community. The assays were carried out in a pilot AS reactor operating for two-weeks under continuous dosage of pollutants. The microbial activity was tracked by measuring oxygen uptake rate, esterase activity, oxidative stress and antioxidant enzyme activities. It was found that IBU and TCS had no acute toxic effects on reactor biomass concentration. TCS led to significant decrease of COD removal efficiency, which dropped from 90% to 35%. Continuous exposure to IBU, TCS and their mixtures increased the activities of glutathione s-transferase (GST) and esterase as a response to oxidative damage. A high increase in GST activity was associated with non-reversible toxic damage while peaks of esterase activity combined with moderate GST increase were attributed to an adaptive response.

Proteomic analysis and antibacterial resistance mechanisms of Salmonella Enteritidis submitted to the inhibitory effect of Origanum vulgare essential oil, thymol and carvacrol

Biological properties of natural products are an important research target and essential oils (EO) from aromatic plants with antimicrobial properties are well documented. However, their uses are limited, and the mechanisms underlying their antibacterial activity are still not well known. Therefore, our objective was to evaluate the antibacterial activities of Origanum vulgare EO, thymol and carvacrol against Salmonella Enteritidis ATCC 13076 strain, particularly regarding the bacterial proteic profile, enzymatic activities and DNA synthesis. Bacterial expressed proteins were evaluated using an untreated assay control and treatments with sublethal concentrations of oregano EO, carvacrol and thymol. The same protein extracts were also assayed for oxidative stress and energy metabolism enzyme activities, as well as effect on DNA synthesis. Protein expression outcomes revealed by 2D-SDS-PAGE, from antimicrobial actions, showed a stress response with differential expressions of chaperones and cellular protein synthesis mediated by the bacterial signaling system. In addition, Salmonella used a similar mechanism in defense against oxidative stress, for its survival. Thus, the antibacterial inhibitory activity of EO was preferentially associated with the presence of thymol and there was interference in protein regulation as well as DNA synthesis affected by these compounds. SignificanceAntimicrobial activity of essential oils (EO) is already known. In this way, the understanding of how this activity occurs is a fundamental part to provide the practical and rational use of these substances. In the current scenario, where the emergence of resistant bacteria or even multiresistant bacteria against conventional antimicrobials, the search for alternatives becomes essential, since the discovery of new inhibitory substances does not occur at the same speed. The anti-Salmonella action allied to the knowledge about the biological processes affected by O. vulgare EO contribute to these bioactive compounds being effectively used as agents in the safety and shelf life of food in a future product, packaging or process where the antibacterial activity is safe and best used.

Effects of the use of bioceramic wraps in patients with lower limb venous ulcers: A randomized double-blind placebo-controlled trial

BackgroundVenous ulcer represents the most advanced stage of chronic venous insufficiency. It is an important public health problem and has a significant impact on patients’ quality of life due to chronic pain, inability to work, need for hospitalization and frequent outpatient follow-up. ObjectiveWe investigated the treatment benefits of far-infrared ceramic (cFIR), in a 90-day study of lower limb venous ulcers and looked at ulcer healing scores, quality of life, serum bio-markers of oxidative stress and antioxidant defense enzymes. Design, setting, participants and interventionsThis is a randomized double-blind placebo-controlled study conducted in the Vascular Surgery Service of a hospital located in the northwest region of the State of Rio Grande do Sul, Brazil. We included patients with lower limb venous ulcers who were randomized to use either a bioceramics wrap or a placebo wrap for 90 days. Main outcome measuresThe following evaluations were conducted at baseline and after 15, 30, 60 and 90 days: ulcer healing score, quality of life, and serum markers of oxidative stress and antioxidant enzyme activity. ResultsPatients (n = 24) with lower limb venous ulcers were randomized into two treatment groups. cFIR decreased the ulcer size on day 30 (P = 0.042) and 90 (P = 0.034) and the total ulcer healing scale scores on day 30 (P = 0.049) and 90 (P = 0.02) of the treatment, when compared to baseline. Additionally, cFIR improved tissue type (epithelial tissue) on day 60 (P = 0.022) when compared to baseline evaluation. ConclusioncFIR clinically improved ulcer healing in patients with lower limb venous ulcers. Trial registrationRBR-8c7xzn on ReBEC.

Renal histopathological and biochemical changes following adjuvant intervention of Momordica charantia and antiretroviral therapy in diabetic rats.

Objective(s):Diabetic nephropathy (DN) is an important primary cause of end-stage kidney disease. This study explores the mechanisms of the reno-protective effects of Momordica charantia (M. charantia) in diabetic rats following treatment with highly active antiretroviral therapy (HAART) regimen triplavar. Materials and Methods:Adult male Sprague-Dawley rats (n=48) were divided into 7 groups (A-G).Treatment groups (B-G) had 7 animals per group and control group (Group A) had 6 animals per group. Diabetes was induced with streptozotocin (STZ) by intraperitoneal injection (STZ 45 mg/kg body weight). The animals were euthanized on the tenth week with kidneys removed for examination and blood obtained via cardiac puncture. Results:Key renal parameters showed no albuminuria, normal blood urea nitrogen (BUN), serum creatinine and electrolytes in all groups treated with M. charantia. Untreated diabetic (Group B) and HAART treated diabetic (Group C) showed severe albuminuria, a significantly raised BUN and serum creatinine (P<0.05) and gross electrolyte disturbances. Blood glucose levels were consistently and significantly raised in all groups not receiving the adjuvant M. charantia (P<0.05). Levels of oxidative stress enzymes Superoxide dismutase (SOD), Catalase and activities of Reduced Gluthaione (GSH) and Malondiadehyde (MDA) were significantly lower in all groups not receiving M. charantia. Histopathology in untreated diabetic and HAART treated animals showed severe degenerative changes in the glomeruli and inflammatory cellular infiltration while M. charantia treated animals showed an essentially normal glomerular appearance with capillary loops and normal cytoarchitecture. Conclusion: M. charantia extract administration improved blood glucose levels, reinstates renal function, reduces body weight loss and restores hyperglycemia.

Tetracycline affects the toxicity of P25 n-TiO2 towards marine microalgae Chlorella sp.

Pollutants such as n-TiO2 and tetracycline enter the marine environment through various sources starting from their production until disposal. Hence, it is vital to determine the interactive effect of one pollutant with the other when they coexist in the environment. In the present study, the effect of antibiotic – tetracycline (TC) on the toxicity of P25 n-TiO2 was studied with marine microalgae, Chlorella sp. The impact of TC (1 mg L−1) on five different concentrations of n-TiO2 (0.25, 0.5, 1, 2 and 4 mg L−1) under both visible and UV-A illuminations was evaluated. Effective diameter of n-TiO2 in ASW at 0th h increased from 690.69 ± 19.55 nm (0.25 mg L−1) to 1183.04 ± 37.10 nm (0.25 mg L−1 + 1 mg L−1) and 971.51 ± 14.61 nm (4 mg L−1) to 1324.12 ± 11.59 nm (4 mg L−1 + 1 mg L−1) in presence of TC. A significant increase in the toxicity of 4 mg L−1 n-TiO2 upon the addition of TC (68.16 ± 0.37% under visible and 80.21 ± 0.3% under UV-A condition) was observed. No significant difference in toxicity was observed between visible and UV-A illuminations. Further the toxicity data was corroborated through the measurement of oxidative stress and antioxidant enzyme activities. Independent action model showed antagonistic effect for lower concentrations of n-TiO2 and additive effect for higher concentrations of n-TiO2 when present in mixture with TC under both illuminations. For the higher mixture concentration of 4 mg L−1 n-TiO2 and 1 mg L−1 TC, the percentage TC removal was about 55.29% and 30% and the corresponding TOC removal was found to be 54.29% and 31.04% under visible and UV-A illuminations respectively. The site of ROS generation in Chlorella sp. was identified with electron transfer chain inhibitors. Both mitochondria and chloroplast acted as the site for the ROS generation in Chlorella sp. The SEM images of the algal cells upon exposure to n-TiO2 and mixture revealed the aggregation of cells and distortion of cell membrane.

Oxidative stress and differential antioxidant enzyme activity in glyphosate-resistant and -sensitive hairy fleabane in response to glyphosate treatment

ABSTRACT Biochemical assays in a time-course were employed to evaluate stresses induced by glyphosate treatment in resistant and sensitive biotypes of Conyza bonariensis. Two experiments were conducted assessing glyphosate doses and time-course after treatment. The doses of glyphosate ranged from 0 to 11840 g ae·ha–1 and assessments performed until 552 h after glyphosate treatment (HAT). The objectives of this study were to evaluate the oxidative stress and differential antioxidant enzyme activity in glyphosate-resistant and -sensitive biotypes of hairy fleabane after glyphosate treatment. After treatment, both studied biotypes accumulated similar levels of shikimic-acid until 96 h. The sensitive biotype died at192 HAT. Shikimic-acid and hydrogen peroxide (H2O2) accumulation in glyphosate-resistant biotype were transient and did not differ from untreated plants at 288 and 500 HAT, respectively. In both glyphosate-resistant and -sensitive biotypes, a correlation analysis established a cause-and-effect relationship after glyphosate treatment, which leads to shikimic-acid and hydrogen peroxide accumulation, lipid peroxidation (indicates tissue damage) and an enhancement in the activity of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) enzyme. However, in the glyphosate-resistant biotype, the oxidative stress and tissue damage were lower, and antioxidant enzyme activities SOD, CAT, and APX were higher than in the -sensitive biotype. It indicates that antioxidant enzyme in glyphosate-resistant biotype might be related to the glyphosate-resistance process in Conyza bonariensis. This study is the first report of differential antioxidant enzyme activity in hairy fleabane.

HO-1 reduces heat stress-induced apoptosis in bovine granulosa cells by suppressing oxidative stress.

Heat stress negatively affects reproduction in cattle by disrupting the normal function of ovarian granulosa cells (GCs), ultimately leading to oxidative damage and cell death via apoptosis. Heme oxygenase-1(HO-1) is a member of the heat shock protein family, which are associated with cellular antioxidant defenses and anti-apoptotic functions. Recent studies demonstrated that HO-1 is upregulated in heat-stressed cells. In the present study, we investigated the expression of HO-1 in bovine GCs transiently exposed to heat stress and characterized the expression and activity of key oxidative stress enzymes and molecules. We show that heat stress induced oxidative stress and apoptosis, and enhanced Nrf2 and HO-1 expression in primary GC cultures. Knocking down HO-1 expression using siRNA exacerbated both oxidative stress and apoptosis, whereas pre-treating GCs with hemin, which induces HO-1 expression, partially prevented these effects. These findings demonstrate that HO-1 attenuates heat stress-induced apoptosis in bovine GCs by decreasing production of reactive oxygen species and activating the antioxidant response.