Activity Of Antioxidant Superoxide Dismutase Research Articles

Anticancer effects of saponin and saponin–phospholipid complex of Panax notoginseng grown in Vietnam

ObjectiveTo evaluate the antitumor activity both in vitro and in vivo of saponin–phospholipid complex of Panax notoginseng. MethodsThe in vitro cytotoxic effect of saponins extract and saponin–phospholipid complex against human lung cancer NCI-H460 and breast cancer cell lines BT474 was examined using MTS assay. For in vivo evaluation of antitumor potential, saponin and saponin–phospholipid complex were administered orally in rats induced mammary carcinogenesis by 7,12-dimethylbenz(a)anthracene, for 30 days. ResultsOur data showed that saponin–phospholipid complex had stronger anticancer effect compared to saponin extract. The IC50 values of saponin–phospholipid complex and saponin extract for NCI-H460 cell lines were 28.47 μg/mL and 47.97 μg/mL, respectively and these values for BT474 cells were 53.18 μg/mL and 86.24 μg/mL, respectively. In vivo experiments, administration of saponin, saponin–phospholipid complex and paclitaxel (positive control) effectively suppressed 7,12-dimethylbenz(a) anthracene-induced breast cancer evidenced by a decrease in tumor volume, the reduction of lipid peroxidation level and increase in the body weight, and elevated the enzymatic antioxidant activities of superoxide dismutase, catalase, glutathione peroxidase in rat breast tissue. ConclusionsOur study suggests that saponin extract from Panax notoginseng and saponin–phospholipid complex have potential to prevent cancer, especially breast cancer.

Deferoxamine alleviates liver fibrosis induced by CCl4 in rats.

Several chronic liver diseases can lead to the occurrence of hepatic fibrosis through the accumulation of iron, which causes induction of oxidative stress and consequently activation of fibrogenesis. The present study was designed to investigate the potential antifibrotic and anti-oxidant effects of deferoxamine (DFO), a well-known iron chelator in an experimental rat model of liver injury using carbon tetrachloride (CCl4 ). First, the potential effective dose of DFO was screened against CCl4 -induced acute hepatotoxicity. Then, rats were co-treated with DFO (300mg/kg, i.p.) for 6weeks starting from the third week of CCl4 induction of chronic hepatotoxicity. Liver function was assessed in addition to histopathological examination. Furthermore, oxidative stress and fibrosis markers were assessed. It was found that treatment of animals with DFO significantly counteracted the changes in liver function; histopathological lesions and hepatic iron deposition that were induced by CCl4 . DFO also significantly counteracted the CCl4 -induced lipid peroxidation increase and reduction in antioxidant activities of superoxide dismutase and glutathione peroxidase enzymes. In addition, DFO ameliorated significantly liver fibrosis markers including hydroxyproline, collagen accumulation, and the expression of the hepatic stellate cells (HSCs) activation marker; alpha smooth muscle actin and transforming growth factor-beta (TGF-β). Together, these findings indicate that DFO possesses a potent antifibrotic effect due to its antioxidant properties that counteracted oxidative stress and lipid peroxidation and restored antioxidant enzymes activities as well as reducing HSCs activation and fibrogenesis.

The effects of quercetin on liver regeneration after liver resection in rats.

The aim of the present study was to assess the influence of quercetine (QE) on liver regeneration after partial hepatectomy (PH) in rats. A total of 24 male Wistar albino rats were divided into three groups: sham-operated (SH), PH and PH+QE; each group contain 8 animals. The rats in QE-treated groups were given QE (15 mg/kg body weight) once a day i.p., for 7 days starting 3 days prior to hepatectomy operation. At 7 days after resection, liver samples were collected. The malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH) levels were estimated in liver homogenates. Moreover, histopathological examination, mitotic index (MI), proliferating cell nuclear antigen labelling, proliferation index (PI), transferase-mediated dUTP nick end-labelling assay, apoptotic index (AI) were evaluated at 7 days after hepatectomy. As a result, QE significantly increased MI, PI, and significantly decreased AI in PH rats. Additionally, QE remarkably inhibited the elevation of MDA, restored impaired antioxidant SOD activity and GSH level, and also attenuated hepatic vacuolar degeneration and sinusoidal congestion. These results suggested that QE treatment had a beneficial effect on liver regenerative capacity of the remnant liver tissue after hepatectomy, probably due to its antioxidative, antiapoptotic and proliferative property.

The effects of quercetin on liver regeneration after liver resection in rats.

The aim of the present study was to assess the influence of quercetine (QE) on liver regeneration after partial hepatectomy (PH) in rats. A total of 24 male Wistar albino rats were divided into three groups: sham-operated (SH), PH and PH+QE; each group contain 8 animals. The rats in QE-treated groups were given QE (15 mg/kg body weight) once a day i.p., for 7 days starting 3 days prior to hepatectomy operation. At 7 days after resection, liver samples were collected. The malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH) levels were estimated in liver homogenates. Moreover, histopathological examination, mitotic index (MI), proliferating cell nuclear antigen labelling, proliferation index (PI), transferase-mediated dUTP nick end-labelling assay, apoptotic index (AI) were evaluated at 7 days after hepatectomy. As a result, QE significantly increased MI, PI, and significantly decreased AI in PH rats. Additionally, QE remarkably inhibited the elevation of MDA, restored impaired antioxidant SOD activity and GSH level, and also attenuated hepatic vacuolar degeneration and sinusoidal congestion. These results suggested that QE treatment had a beneficial effect on liver regenerative capacity of the remnant liver tissue after hepatectomy, probably due to its antioxidative, antiapoptotic and proliferative property.

Antioxidant status in streptozotocin induced diabetic rats treated with vanadium complex

As lipid peroxidation and oxidative stress play a key role in the pathogenesis of diabetes, the antioxidant status of streptozotocin induced diabetic rats, treated with vanadium complex was explored in the present study. Diabetes was induced by single intraperitoneal injection of streptozotocin (STZ) at the dose rate of 45 mg per kg body weight. Diabetes was confirmed after 72 hours of STZ injection by estimating blood glucose level and those rats showing more than 250 mg/ dL were considered as diabetic. Vanadium complex at the dose rates of 5 and 10 mg / kg body weight was administered orally to normal control and STZ induced diabetic rats. Glimepiride was used as the positive control and was given orally at the dose rate of 800 μg / Kg body weight. The study on the hepatic, renal and pancreatic tissues showed that vanadium complex at both the predetermined dosages significantly increased the antioxidant activities of superoxide dismutase and glutathione peroxidase along with a significant increase in the level of glutathione and a significant decrease in the level of lipid peroxidation. The study also revealed that there is a significant reduction in the activity of catalase after treatment with vanadium complex at both the dosage levels.

The essential oil of Artemisia capillaris protects against CCl4-induced liver injury in vivo

To study the hepatoprotective effect of the essential oil of Artemisia capillaris Thunb., Asteraceae, on CCl4-induced liver injury in mice, the levels of serum aspartate aminotransferase and alanine aminotransferase, hepatic levels of reduced glutathione, activity of glutathione peroxidase, and the activities of superoxide dismutase and malondialdehyde were assayed. Administration of the essential oil of A. capillaris at 100 and 50mg/kg to mice prior to CCl4 injection was shown to confer stronger in vivo protective effects and could observably antagonize the CCl4-induced increase in the serum alanine aminotransferase and aspartate aminotransferase activities and malondialdehyde levels as well as prevent CCl4-induced decrease in the antioxidant superoxide dismutase activity, glutathione level and glutathione peroxidase activity (p<0.01). The oil mainly contained β-citronellol, 1,8-cineole, camphor, linalool, α-pinene, β-pinene, thymol and myrcene. This finding demonstrates that the essential oil of A. capillaris can protect hepatic function against CCl4-induced liver injury in mice.

Influence of abiotic stress preconditioning on antioxidant enzymes in shoot tips of Lomandra sonderi (Asparagaceae) prior to cryostorage

Lomandra sonderi (F.Muell.) Ewart (Asparagaceae) is endemic to the south-west Western Australian jarrah (Eucalyptus marginata Donn ex Sm.) forest region, and is a difficult to propagate species important to post-mining restoration. Micropropagation is the only way to currently produce plants of this species for restoration. This study describes investigations into optimising cryopreservation for efficient long-term germplasm storage. In order to investigate the effect of preconditioning on post-cryogenic survival of shoot tips, in vitro grown plants were exposed to a range of light-, temperature- and osmotic-induced preconditioning treatments under culture room conditions for 3 weeks. Room temperature (24°C) preconditioning resulted in the greatest post-cryogenic survival, followed by low light (17 µmol m–2 s–1) preconditioning. Alternating temperature (25/5°C), high temperature (35°C), high sucrose (180 mM) and high light (93 µmol m–2 s–1) preconditioning treatments all led to significantly and progressively lower post-cryogenic shoot tip survival than room temperature preconditioning. Antioxidant activity of superoxide dismutase in preconditioned shoot tips showed a positive correlation to post-cryogenic survival overall, whereas the activities of glutathione reductase, glutathione peroxidase and catalase showed little correlation. Analysis throughout the cryopreservation protocol showed that the activity of glutathione reductase decreased significantly after cryopreservation, whilst the activity of glutathione peroxidase and catalase did not change.

Lipoxin A4 Preconditioning Attenuates Intestinal Ischemia Reperfusion Injury through Keap1/Nrf2 Pathway in a Lipoxin A4 Receptor Independent Manner

Oxidative stress plays a critical role in the pathogenesis of intestinal ischemia reperfusion (IIR) injury. Enhancement in endogenous Lipoxin A4 (LXA4), a potent antioxidant and mediator, is associated with attenuation of IIR. However, the effects of LXA4 on IIR injury and the potential mechanisms are unknown. In a rat IIR (ischemia 45 minutes and subsequent reperfusion 6 hours) model, IIR caused intestinal injury, evidenced by increased serum diamine oxidase, D-lactic acid, intestinal-type fatty acid-binding protein, and the oxidative stress marker 15-F2t-Isoprostane. LXA4 treatment significantly attenuated IIR injury by reducing mucosal 15-F2t-Isoprostane and elevating endogenous antioxidant superoxide dismutase activity, accompanied with Keap1/Nrf2 pathway activation. Meanwhile, LXA4 receptor antagonist Boc-2 reversed the protective effects of LXA4 on intestinal injury but failed to affect the oxidative stress and the related Nrf2 pathway. Furthermore, Nrf2 antagonist brusatol reversed the antioxidant effects conferred by LXA4 and led to exacerbation of intestinal epithelium cells oxidative stress and apoptosis, finally resulting in a decrease of survival rate of rat. Meanwhile, LXA4 pretreatment upregulated nuclear Nrf2 level and reduced hypoxia/reoxygenation-induced IEC-6 cell damage and Nrf2 siRNA reversed this protective effect of LXA4 in vitro. In conclusion, these findings suggest that LXA4 ameliorates IIR injury by activating Keap1/Nrf2 pathway in a LXA4 receptor independent manner.

Insecticidal activity of chlorine dioxide gas by inducing an oxidative stress to the red flour beetle, Tribolium castaneum

Chlorine dioxide (ClO2) is a commercial bleaching and disinfection agent. Its fumigant formulation at 200 ppm for 24 h exposure gave a complete lethality to both larvae and adults of the red flour beetle, Tribolium castaneum. This study set up a hypothesis that oxidative stress induced by ClO2 treatment is a main factor to kill the beetles. To test this hypothesis, two antioxidant enzymes (superoxide dismutase (SOD) and thioredoxin-peroxidase (Tpx)) were annotated from the insect genome and analyzed in their functional links to oxidative stress. An oxidative stress to T. castaneum was simulated by an immune challenge. Gene expressions of both SOD and Tpx were upregulated in the larvae challenged by bacteria. Similarly, an exposure to ClO2 gas significantly induced the larvae to up-regulate the gene expressions of both SOD and Tpx. Either RNA interference of SOD or Tpx using specific double-stranded RNAs significantly enhanced the lethal activity of the ClO2 gas treatment. Reactive oxygen species (ROS) amounts were significantly enhanced by the bacterial challenge or ClO2 treatment. These results suggest that ClO2 gas induces an oxidative stress by generating ROS, which can be detoxified by the antioxidant activities of SOD and Tpx of T. castaneum. Thus, the excessive oxidative stress derived from a lethal concentration of ClO2 is an insecticidal factor against T. castaneum.

24-Epibrassinoslide enhances plant tolerance to stress from low temperatures and poor light intensities in tomato (Lycopersicon esculentum Mill.).

Brassinosteroids (Brs) are a newly recognized group of active steroidal hormones that occur at low concentrations in all plant parts and one of the active and stable forms is 24-epibrassinolide (EBR). We investigated the effect of EBR on tomato (Lycopersicon esculentum Mill.) and its mechanism when seedlings were exposed to low temperature and poor light stress conditions. Leaves of stress-tolerant 'Zhongza9' and stress-sensitive 'Zhongshu4' cultivars were pre-treated with spray solutions containing either 0.1 μM EBR or no EBR (control). The plants were then transferred to chambers where they were exposed to low temperatures of 12 °C/6 °C (day/night) under a low light (LL) level of 80 μmol · m(-2) · s(-1). Exogenous application of EBR significantly increased the antioxidant activity of superoxide dismutase, catalase and peroxidase, and decreased the rate of O2 · (-) formation and H2O2 and malondialdehyde contents. Additionally, the ATP synthase β subunit content was increased by exogenous hormone application. Based on these results, we conclude that exogenous EBR can elicit synergism between the antioxidant enzyme systems and the ATP synthase β subunit so that scavenging of reactive oxygen species becomes more efficient. These activities enable plants to cope better under combined low temperature and poor light stresses.

Salivary antioxidants of male athletes after aerobic exercise and garlic supplementation on: A randomized, double blind, placebo-controlled study

PurposeProduction of reactive oxygen species and reactive nitrogen species is a natural biological event in metabolism. However, the presence of antioxidants can highly reduce the negative effect of free radicals. Thus, the efficiency of antioxidant system in the physiology of exercise is very important. DesignConsidering the known antioxidant capacity of garlic, the purpose of this study was to evaluate the effect on combining 14 days aerobic exercise till exhaustion with garlic extract supplementation on the antioxidant capacity of saliva. MethodsSixteen young men volunteered to participate in this randomized, double blind, placebo-controlled study and were randomly placed into two groups, placebo (Group I) and garlic extract (Group II). The participants performed exhaustive aerobic exercise on a treadmill before and after supplementation. Their unstimulated salivary samples were collected before, immediately after, and 1h after the activity. The antioxidant activity in terms of peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) was then measured in the collected samples using their specific substrates. ResultsA significant increase in salivary antioxidant activity of SOD, POD, and CAT was observed in saliva of the supplement group compared to the placebo group (P≤0.05). ConclusionThe findings from this study suggest that increased activity of antioxidant enzymes could possibly decrease exercise-induced oxidative damage in male athletes.

Anti-Alzheimers and anti-inflammatory activities of a glycoprotein purified from the edible brown alga Undaria pinnatifida

Undaria pinnatifida Harvey is an edible brown macroalga that has several pharmacologically important traits. We previously described the purification and chemical composition of a glycoprotein from U. pinnatifida (UPGP) and characterized its antioxidant and DNA protection activities. In the present study, we used different in vitro assays to determine the anti-Alzheimer's and anti-inflammatory activities of UPGP. To evaluate the anti-Alzheimer's potentiality of UPGP, the inhibitory activities of acetycholinesterase (AChE), butyrylcholinesterase (BChE), and β-secretase (BACE1) were assessed using standard protocols. Neuronal cell viability was determined with propidium iodide exclusion and lactate dehydrogenase assays using primary hippocampal cells. Anti-inflammatory activity was measured in two ways: first, by measuring nitric oxide (NO) production in lipopolysaccharide (LPS) activated RAW 264.7 macrophages, and second, with the cyclooxygenase (COX) inhibitory assay. The effect of UPGP on the enzymatic antioxidant activities of superoxide dismutase (SOD) and xanthine oxidase (Xox) was also studied. UPGP showed predominantly AChE, BChE, and BACE1 inhibitory activities with IC50 values of 63.56±1.86, 99.03±4.64, and 73.35±2.54μg/mL, respectively. The addition of UPGP (5μg/mL) to the culture medium demonstrated that it was not cytotoxic to cultured hippocampal cells, but rather, protected neurons from natural death. The ability of UPGP to inhibit enzymes COX-1 and COX-2 was determined by calculating the percent inhibition of prostaglandin production, as measured by enzymatic assays. UPGP inhibited COX-1 and COX-2 with IC50 values of 53.03±1.03μg/mL for COX-1 and 193.35±3.08μg/mL for COX-2. UPGP inhibited NO production by 94.2% at a concentration of 100μg/mL; cell viability was 94.64% at this concentration. Moreover, UPGP improved SOD activity (53.45%) and inhibited Xox (82.05%) activity at a concentration of 5mg/mL and 1mg/mL, respectively. These results suggest that UPGP is a bioactive compound with the potential to control AD and inflammatory- and oxidative stress-related diseases.

Bilirubin treatment suppresses pulmonary inflammation in a rat model of smoke-induced emphysema

BackgroundCigarette smoking is a significant risk factor for emphysema, which is characterized by airway inflammation and oxidative damage. ObjectivesTo assess the capacity of bilirubin to protect against smoke-induced emphysema. MethodsSmoking status and bilirubin levels were recorded in 58 patients with chronic obstructive pulmonary diseases (COPD) and 71 non-COPD participants. The impact of smoking on serum bilirubin levels and exogenous bilirubin (20 mg/kg/day) on pulmonary injury was assessed in a rat model of smoking-induced emphysema. At sacrifice lung histology, airway leukocyte accumulation and cytokine and chemokine levels in serum, bronchoalveolar lavage fluid (BALF) and lung were analyzed. Oxidative lipid damage and anti-oxidative components was assessed by measuring malondialdehyde, superoxide dismutase (SOD) activity and glutathione. ResultsTotal serum bilirubin levels were lower in smokers with or without COPD than non-smoking patients without COPD (P < 0.05). Indirect serum bilirubin levels were lower in COPD patients than patients without COPD (P < 0.05). In rats, cigarette smoke reduced serum total and indirect bilirubin levels. Administration of bilirubin reduced mean linear intercept and mean alveoli area, increased mean alveoli number, reduced macrophage, neutrophil and TNF-α content of BALF, and increased BALF and serum IL-10 level, but lowered local and systemic CCL2, CXCL2, CXCL8 and IL-17 levels. Bilirubin suppressed the smoke-induced systemic and regional oxidative lipid damage associated with increased SOD activity. ConclusionBilirubin attenuated smoking-induced pulmonary injury by suppressing inflammatory cell recruitment and pro-inflammatory cytokine secretion, increasing anti-inflammatory cytokine levels, and anti-oxidant SOD activity in a rat model of smoke-induced emphysema.

Azinphos-methyl and chlorpyrifos, alone or in a binary mixture, produce oxidative stress and lipid peroxidation in the freshwater gastropod Planorbarius corneus

Azinphos-methyl (AZM) and chlorpyrifos (CPF) are broad-spectrum organophosphate insecticides used for pest control on a number of food crops in many parts of the world that have been shown to inhibit cholinesterase activity in the non-target freshwater gastropod Planorbarius corneus. The present study was undertaken to determine: (a) whether AZM and CPF induce oxidative stress in P. corneus, and (b) whether a mixture of both organophosphates that causes a higher neurotoxicity than single pesticides also causes an enhanced oxidative stress. To this end, non-enzymatic and enzymatic parameters were measured in the soft tissues of snails acutely exposed to the insecticides in single-chemical (2.5mg AZML−1 and 7.5μgCPFL−1) and a binary-mixture (1.25mgAZML−1 plus 3.75μgCPFL−1) studies. At 24h, all pesticide-exposed groups showed significantly decreased glutathione (GSH) and glutathione disulfide (GSSG) levels when compared to control animals. At 48h, all exposed groups showed an alteration of the redox status (GSH/GSSG ratio) and a significant increase in malondialdehyde levels. The exposure for 48h to AZM and CPF, alone or in the binary mixture, also resulted in a significant decrease of the antioxidant superoxide dismutase activity. The greatest decrease was observed with CPF exposure (59% of decrease relative to the control group). A significant increase in catalase and glutathione S-transferase activities was observed in CPF group and in CPF and AZM+CPF groups, respectively. The activities of glutathione reductase and glucose 6-phosphate dehydrogenase did not show significant changes with respect to controls in any treatment group. In conclusion, the data shown in the present study provide evidence that AZM, CPF and a mixture of both organophosphates are able to induce oxidative stress and oxidative damage in P. corneus tissues. However, no similarities between the degree of neurotoxicity and the degree of alterations of the measured oxidative stress parameters were found.

Performance of Bell Pepper Seeds in Response to Drum Priming with Addition of 24-Epibrassinolide

Drum priming systems are among the most common methods of seed priming for commercial treatment. The supply of water to the seeds is controlled by physical means, and seeds are able to reach a desired moisture content without the use of osmotic solutions for hydration control. The brassinosteroid (BR), 24-epibrassinolide (24-EpiBL), has been shown previously to have a significant effect on seed performance. Therefore, the aim of this study was to verify the feasibility of drum priming associated with added 24-EpiBL on enhancement of bell pepper seed performance. Two bell pepper cultivars (AF-6 and AF-7) were tested, and each cultivar represented, respectively, by three and four seed lots with different initial physiological potentials. Seed performance was determined by evaluating standard germination, initial seedling growth, and changes on the antioxidant activity of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POX). Seed Vigor Imaging System (SVIS®) was used to assess the initial seedling growth. The nondenaturing polyacrylamide gel electrophoresis (PAGE) technique was used to evaluate possible changes in the enzymatic antioxidant system. Several advantages were verified in the drum priming technique with added 24-EpiBL compared with the traditional procedure (water alone). Germination time was reduced followed by a seedling growth increase. Concomitantly, seed enzymatic activity was improved. However, results showed different response for each enzyme. Drum priming with 24-EpiBL demonstrates viability for commercial treatment and enhancement of bell pepper seeds.

Toxicity and bioaccumulation of bromadiolone to earthworm Eisenia fetida

Bromadiolone, a potent second-generation anticoagulant rodenticide, has been extensively used worldwide for the field control of rodents. Invertebrates may be at risk from primary poisoning as a result of bromadiolone bait applications. However, there are few data regarding the toxicity and bioaccumulation of bromadiolone to earthworms. In this study, we reported that bromadiolone was toxic to earthworms at 1mg/kg soil, which is a likely concentration in the field following application of bromadiolone baits. Exposure to bromadiolone resulted in a significant inhibition of earthworm growth. The antioxidant activities of superoxide dismutase and catalase were slightly increased in earthworms, while malondialdehyde content (as a molecular marker indicative of the damage to lipid peroxidation) was dominantly elevated over the duration of exposure. Bromadiolone in soil is bioaccumulative to earthworms. The biota to soil accumulation factors (BSAFs) of bromadiolone were concentration dependent and BSAFs decreased as the level of bromadiolone in soil increased. These results suggest earthworms are not only the potential subject to primary poisoning but also the source of secondary exposure for insectivores and scavengers following application of bromadiolone.

Protective effect of kombucha on rats fed a hypercholesterolemic diet is mediated by its antioxidant activity

Context: Kombucha (KT) is claimed to have various beneficial effects on human health, but there is very little scientific evidence available in the literature.Objective: The present study investigates the effects of Camellia sinensis (GT) Linn. (Theaceae) and KT, two natural drinks, on cholesterol and antioxidant status using a hypercholesterolemia rat model.Materials and methods: The present study compared the free-radical scavenging abilities and polyphenol levels of GT and KT. Wistar rats fed cholesterol-rich diets were given KT or GT (5 mL/kg body weight per day, po) for 16 weeks, then fasted overnight and sacrificed. The plasma lipid levels, thiobarbituric acid reactive substances (TBARS) and aspartate aminotransferase (AST), alanine aminotransferase (ALT), and γ-glutamyl transpeptidase (GGT) serum levels, antioxidant activities of superoxide dismutase (SOD) and catalase (CAT), and creatinine and urea rats were examined.Results: KT had a phenolic compound of 955 ± 0.75 mg GAE/g) followed, by GT (788.92 ± 0.02 mg GAE/g). The free radical scavenging activity of KT was higher than GT. Compared with GT, KT induced lowered serum levels of TC, TG, VLDL-C, and LDL-C by 26, 27, 28, and 36%, respectively, and increased the serum level of high-density lipoprotein cholesterol (HDL-C). KT induced a 55% decrease of TBARS level in liver and 44% in kidney, compared with those of rats fed a cholesterol-rich diet alone. Moreover, CAT and SOD activities were reduced by 29 and 33%, respectively, in liver and 31 and 35%, respectively, in kidney, after oral administration of KT, compared with those of HCD-fed rats.Conclusion: The findings revealed that KT administration induced attractive curative effects on hypercholesterolemic, particularly in terms of liver–kidney functions in rats. Its effect on humans needs to be studied further.

The Role of p21 in Apoptosis, Proliferation, Cell Cycle Arrest, and Antioxidant Activity in UVB-Irradiated Human HaCaT Keratinocytes.

BackgroundSkin cancer is the most common cancer in the United States, and ultraviolet B (UVB) radiation-induced DNA damage is the major environmental factor underlying skin cancer development. p21, a p53-inducible protein, plays a key role in the cellular response to UVB-induced DNA damage.Material/MethodsThrough p21 silencing and overexpression, we investigated the role of p21 in apoptosis, proliferation, cell cycle arrest, and oxidative stress in UVB-irradiated HaCaT keratinocytes.ResultsWe found that UVB exposure induced significant p21 downregulation (p<0.05) and was associated with significantly increased apoptosis, significantly decreased proliferation, and significantly increased G2 phase arrest (p<0.05) in UVB-irradiated HaCaT keratinocytes. p21 silencing significantly promoted apoptosis, significantly inhibited G2 phase arrest, and significantly inhibited proliferation (p<0.05), but after UVB irradiation, p21 silencing demonstrated a less significant pro-apoptotic effect and a more significant inhibition of G2 phase arrest (p<0.05), which was reflected in significantly higher proliferative activity (p<0.05). p21 overexpression acted in an anti-apoptotic manner in the absence of UVB-induced DNA damage but acted in a pro-apoptotic manner in the presence of UVB-induced DNA damage, displaying an “antagonistic duality” similar to other growth-promoting oncoproteins. p53 expression mirrored p21 expression, suggesting a regulatory feedback mechanism between p21 and p53 expression. p21 overexpression significantly downregulated glutathione peroxidase and superoxide dismutase antioxidant activity (p<0.05) while significantly upregulating hydrogen peroxide and malondialdehyde content (p<0.05), suggesting a role in decreasing antioxidant defense capabilities in UVB-irradiated HaCaT keratinocytes.ConclusionsThese findings reveal that p21 may play a key role in HaCaT keratinocytes’ response to UVB exposure.

Effects of the Euterpe Oleracea Mart. (Açai) Extract on Cardiovascular Changes and Oxidative Stress in Spontaneously Hypertensive Rats

Aim The hydroalcoholic extract obtained from seeds of açaí (ASE) is rich in polyphenols which are known to reduce the incidence of cardiovascular diseases. In this study we investigated the effect of treatment with ASE on cardiovascular changes and oxidative stress in spontaneously hypertensive rats (SHR). Methods Wistar and SHR (3 weeks old) received ASE (200 mg.kg-1.day-) or vehicle in drinking water, during 13 weeks. Results Our results demonstrated that the increased systolic blood pressure and carbonyl protein levels observed in the heart of SHR were reduced by ASE. The reduced vasodilator response to acetylcholine (100 pmol) in perfused mesenteric arterial bed (MAB) of SHR was recovered by ASE. Furthermore, antioxidant activity of superoxide dismutase (SOD) was increased in heart and MAB of SHR and normalized by ASE. The activities of glutathione peroxidase (GPx) and catalase (CAT) in MAB, and GPx in the heart were not different between groups. However, ASE increased the activity of CAT in the heart of SHR. The expressions of eNOS and SOD were increased in SHR and unchanged by ASE. The increased medial thickness of the aorta in SHR was reduced by ASE. Conclusion These findings demonstrate that the improvement of endothelial function, vascular remodeling and the antioxidant activity induced by ASE may contribute to the antihypertensive effect of the extract in SHR. Financial Support: FAPERJ e CNPq.

Enhancement on reactive oxygen species and COX-1 mRNA levels modulate the vascular relaxation induced by sodium nitroprusside in denuded mice aorta.

This study aimed to investigate the modulation of nitric oxide/reactive oxygen species in sodium nitroprusside relaxation in mice aorta. Sodium nitroprusside induced relaxation in endothelium-intact (e+) and endothelium-denuded (e-) aortas with greater potency in e+ than in e-. The nitric oxide synthase inhibitor did not alter the sodium nitroprusside relaxation in both e+ and e- aortas. However, the superoxide anion scavenger abolished the difference in sodium nitroprusside potency between e+ and e-. Sodium nitroprusside reduced dihydroethidium-derived fluorescent products in both groups; however, the difference between intact and denuded mice aorta remains. The glutathione levels and basal antioxidant activity of superoxide dismutase were reduced in e- aorta when compared with e+, and these values were not altered by sodium nitroprusside. Confirming these results, the levels of lipid peroxidation in e+ were significantly lower when compared to e-, and these values were not altered by sodium nitroprusside. The sodium nitroprusside potency in the presence of a nonselective COX inhibitor or the EP/DP prostaglandin receptor antagonist in endothelium denuded was similar to that in intact mice aorta. Based on these results, we performed the COX-1 and COX-2 mRNA level studies, and in denuded mice aorta, there was an upregulation in COX-1 mRNA levels. Taken together, our findings show that in the absence of endothelium, there is an enhancement of superoxide levels, leading to GSH consumption and higher levels of lipid peroxidation, showing an intense redox status. Furthermore, in denuded mice aorta, there was an upregulation of COX-1 mRNA expression, leading to vasoconstrictor prostanoids synthesis. The interaction of vasoconstrictor prostanoids with its receptors EP/DP negatively modulates the vascular relaxation induced by SNP in denuded mice aorta.