Effects of Antioxidants Coenzyme Q10 and Lipoic Acid on Interleukin-1β-Mediated Inhibition of Glucose-Stimulated Insulin Release from Cultured Mouse Pancreatic Islets

During the development of the autoimmune disease, insulin-dependent diabetes mellitus (IDDM) islet cell death is thought to be mediated in part by oxygen and nitrogen free radicals and interleukin 1β (IL-1β), secreted by activated macrophages. Free radicals disrupt the homeostasis of biological systems by damaging major constituent molecules such as lipids, proteins, and DNA. Islet cells are quite susceptible to oxidative damage due to low levels of antioxidant enzymes involved in free radical consumption. If IDDM is associated with an imbalance of oxidative stresses and antioxidant responses in islet cells, then it may be possible to ameliorate disease by supplementating antioxidant defenses. In this study, the antioxidants coenzyme Q10 and lipoic acid were able to block IL-1β-mediated inhibition of glucose-stimulated insulin secretion from islet cells at 10^{? 12} M and 10^{? 9} M, respectively.     

Bottom-up analysis of emergent properties of N-acetylcysteine as an adjuvant therapy for COVID-19

N-acetylcysteine (NAC) is an abundantly available antioxidant with a wide range of antidotal properties currently best studied for its use in treating acetaminophen overdose. It has a robustly established safety profile with easily tolerated side effects and presents the Food and Drug Administration's approval for use in treating acetaminophen overdose patients. It has been proven efficacious in off-label uses, such as in respiratory diseases, heart disease, cancer, human immunodeficiency virus infection, and seasonal influenza. Clinical trials have recently shown that NAC's capacity to replenish glutathione stores may significantly improve coronavirus disease 2019 (COVID-19) outcomes, especially in high risk individuals. Interestingly, individuals with glucose 6-phosphate dehydrogenase deficiency have been shown to experience even greater benefit. The same study has concluded that NAC's ability to mitigate the impact of the cytokine storm and prevent elevation of liver enzymes, C-reactive protein, and ferritin is associated with higher success rates weaning from the ventilator and return to normal function in COVID-19 patients. Considering the background knowledge of biochemistry, current uses of NAC in clinical practice, and newly acquired evidence on its potential efficacy against COVID-19, it is worthwhile to investigate further whether this agent can be used as a treatment or adjuvant for COVID-19.     

酢浆草体外抗炎抗氧化检测方法的建立和优化

目的优化和建立酢浆草体外抗炎抗氧化活性的检测方法。方法建立抗氧化、蛋白酶活性抑制和蛋白变性抑制活性的检测方法。比较醇提水沉法和水提醇沉法、不同保存条件下药物的活性。结果优化检测方法后,不同浓度酢浆草样品的检测结果具有高度相关性,表明检测方法高度稳定且准确可靠。经醇提水沉法和水提醇沉法后,酢浆草的抗氧化活性为100%,蛋白变性抑制活性为90%,酶活性抑制活性为50%,两者出峰位置基本一致。醇提水沉法更易快速获得澄清的提取溶液。室温和4℃冷藏时,蛋白变性抑制成分第3天时均下降40%,第7天时下降至无活性;酶活性抑制成分在冷藏时下降比室温条件慢,在第7天时分别下降30%和60%;抗氧化成分在2种保存条件下均有较高活性。结论所建立的方法可用于体外检测酢浆草的抗炎活性。     

UPLC-QTOF-MS fingerprinting combined with chemometrics to assess the solvent extraction efficiency,phytochemical variation,and antioxidant activities of Beta vulgaris L.

Accurate assays of plant antioxidants and other phytochemicals require efficient extraction conditions and enable rigorous assessments of crop varieties and production systems. This study assessed the extraction of phytochemicals and antioxidants from conventionally or organically grown red and golden beets (Beta vulgaris L.), using twenty solvent (S1–S20) mixtures containing water, methanol, and ethanol alone or with acids (ascorbic, formic, acetic). Red beetroot extracted with methanol with or without acid had the highest betanin content (2791.0 μg/g and 8222.3 μg/g of fresh weight [FW], respectively) and golden beetroot extracted with methanol/ascorbic acid/water had the highest vulgaxanthin I (193.7 μg/g and 15.0 μg/g of FW, respectively). The radical-scavenging activity and total phenolics in beetroot extracts reflected the different extraction efficiency of each solvent. UHPLC-QTOF-MS was used to identify twenty-seven phytochemicals, including 23 betalains, 2 amino acids, and 2 phenolic acids. Chemometric approaches discriminated the beet varieties and different extracts within one variety based on the composition and abundance of the key phytochemicals. The red beetroot extracted with aqueous ethanol with or without acid (S5, S7, S8, S9), and golden beetroot extracted with methanol-containing solvents (S15 for conventionally and S20 for organically) had the highest levels of phytochemicals, suggesting that these conditions efficiently extract key phytochemicals.     

Antioxidative effects of cysteamine,hyaluronan and fetuin on post‐thaw semen quality,DNA integrity and oxidative stress parameters in the Brown Swiss bull

The aim of this study was to compare the effectiveness of antioxidants including cysteamine (2.5, 7.5 mm ), hyaluronan (0.25, 1 mg ml^?1) and fetuin (5, 10 mg ml^?1) in the freezing of Brown Swiss bull semen. The best percentages of CASA motilities were achieved with 10 mg ml^?1 of fetuin and 2.5 mm of cysteamine. For sperm morphology, 10 mg ml^?1 of fetuin and 2.5 mm of cysteamine had better protective effects (P < 0.001). The results of hypo‐osmotic swelling test showed that the percentage values of membrane integrity in all the groups, excluding that supplemented with 5 mg ml^?1 of fetuin, were higher than those of the control group (P < 0.001). Results obtained for the DNA damage of sperm cells demonstrated that 0.25 mg ml^?1 of hyaluronan, and 2.5 and 7.5 mm of cysteamine led to lower rates of spermatozoa with damaged DNA, compared with the control group (P < 0.001). The maintenance of superoxide dismutase and glutathione peroxidase antioxidant activities following freeze‐thawing with 2.5 and 7.5 mm of cysteamine and 10 mg ml^?1 of fetuin was demonstrated to be at a higher level in comparison with the control group (P < 0.001). Malondialdehyde formation was found to be lower in the groups supplemented with 0.25 mg ml^?1 of hyaluronan and 7.5 mm of cysteamine after the freeze‐thawing process (P < 0.001).     

Melatonin protects testes against lithium‐pilocarpine‐induced temporal lobe epilepsy in rats: a time course study

Male dysfunction is common in patients with temporal lobe epilepsy (TLE). We evaluated whether melatonin, as a supplement, can play a positive role in reducing the epileptogenesis imposing abnormalities of spermatozoa and testes in epileptic rats. Status epilepticus was induced based on the TLE lithium‐pilocarpine model. Two patterns of melatonin were administered to the epileptic animals along the mean durations of latent (14 days) and chronic (60 days) phases. Sperm parameters, different antioxidant enzyme levels, germ cell apoptosis, body and relative sex organ weights were evaluated in all groups 60 days following SE induction. Chronic TLE caused a significant reduction in sperm parameters. In the testis, the reduced level of antioxidant enzymes was accompanied by a significant increase in malondialdehyde concentration. The presence of oxidant condition in the testes of epileptic animals caused expanded apoptosis in the germ cell layer. Moreover, the amount of weight gain in epileptic animals was more prominent. Melatonin administration was able to improve sperm motility by increasing the total antioxidant level. There was also a significant reduction in the spermatogenic cell line apoptosis and the extra weight gain of melatonin‐treated animals. Melatonin supplementation might be considered as an acceptable cotreatment in epileptic patients.     

Serum bilirubin as a predictor of incident metabolic syndrome: A 4-year retrospective longitudinal study of 6205 initially healthy Korean men

AimSerum bilirubin is an endogenous antioxidant with anti-inflammatory properties. Several cross-sectional studies have reported that bilirubin was negatively associated with oxidative stress-mediated diseases, including the metabolic syndrome (MetS). However, the clinical relevance of bilirubin as a risk factor for incident MetS remains controversial. For this reason, the longitudinal effects of baseline serum bilirubin concentrations on incident MetS were evaluated in Korean men.MethodsThis 4-year retrospective longitudinal observational study involved 6205 Korean men without MetS. Subjects underwent routine health examinations in 2007 and returned for a follow-up examination in 2011. Baseline serum bilirubin concentrations were determined using the vanadate oxidation method.ResultsDuring the 4-year period, 936 cases of incident MetS (15.1%) were identified. Its incidence decreased across baseline bilirubin quartile categories (P < 0.001), with an odds ratio (OR) for developing MetS being significantly lower in the highest quartile group (≥ 1.40 mg/dL) compared with the lowest (≤ 0.90 mg/dL) after adjusting for all confounding variables [OR = 0.70, 95% confidence interval (CI) 0.54–0.90; P for trend = 0.019]. Among individual components of MetS, bilirubin was found to be negatively associated with only the risk of incident hypertriglyceridaemia. The OR (95% CI) for incident hypertriglyceridaemia in the highest vs lowest quartile was 0.75 (0.61–0.91; P for trend = 0.002).ConclusionSerum total bilirubin level was negatively associated with incidence of MetS in healthy Korean men over a 4-year period.     

The role of epidermal growth factor in prevention of oxidative injury and apoptosis induced by intestinal ischemia/reperfusion in rats

Intestinal ischemia/reperfusion is a major problem which may lead to multiorgan failure and death. The aim of the study was to evaluate the effects of epidermal growth factor (EGF) on apoptosis, cell proliferation, oxidative stress and the antioxidant system in intestinal injury induced by ischemia/reperfusion in rats and to determine if EGF can ameliorate these toxic effects. Intestinal ischemia/reperfusion injury was produced by causing complete occlusion of the superior mesenteric artery for 60 min followed by a 60-min reperfusion period. Animals received intraperitoneal injections of 150 μg/kg human recombinant EGF 30 min prior to the mesenteric ischemia/reperfusion. Mesenteric ischemia/reperfusion caused degeneration of the intestinal mucosa, inhibition of cell proliferation, stimulation of apoptosis and oxidative stress in the small intestine of rats. In the ischemia/reperfusion group, lipid peroxidation was stimulated accompanied by increased intestinal catalase and glutathione peroxidase activities, however, glutathione levels and superoxide dismutase activities were markedly decreased. EGF treatment to rats with ischemia/reperfusion prevented the ischemia/reperfusion-induced oxidative injury by reducing apoptosis and lipid peroxidation, and by increasing antioxidant enzyme activities. These results demonstrate that EGF has beneficial antiapoptotic and antioxidant effects on intestinal injury induced by ischemia/reperfusion in rats.     

Phytochemical screening,anti-oxidant activity and in vitro anticancer potential of ethanolic and water leaves extracts of Annona muricata (Graviola)

ObjectiveTo determine the phytochemical composition, antioxidant and anticancer activities of ethanolic and water leaves extracts of Annona muricata (A. muricata) from the Eastern Uganda.MethodsPhytochemical screening was conducted using standard qualitative methods and a Chi-square goodness of fit test was used to assign the relative abundance of the different phytochemicals. The antioxidant activity was determined using the 2, 2-diphenyl-2-picrylhydrazyl and reducing power methods whereas the in vitro anticancer activity was determined using three different cell lines.ResultsPhytochemical screening of the extracts revealed that they were rich in secondary class metabolite compounds such as alkaloids, saponins, terpenoids, flavonoids, coumarins and lactones, anthraquinones, tannins, cardiac glycosides, phenols and phytosterols. Total phenolics in the water extract were (683.69±0.09) μg/mL gallic acid equivalents (GAE) while it was (372.92±0.15) μg/mL GAE in the ethanolic extract. The reducing power was 216.41 μg/mL in the water extract and 470.51 μg/mL GAE in the ethanolic extract. In vitro antioxidant activity IC₅₀ was 2.0456 mg/mL and 0.9077 mg/mL for ethanolic and water leaves extracts of A. muricata respectively. The ethanolic leaves extract was found to be selectively cytotoxic in vitro to tumor cell lines (EACC, MDA and SKBR3) with IC₅₀ values of 335.85 μg/mL, 248.77 μg/mL, 202.33 μg/mL respectively, while it had no cytotoxic effect on normal spleen cells. The data also showed that water leaves extract of A. muricata had no anticancer effect at all tested concentrations.ConclusionsThe results showed that A. muricata was a promising new antioxidant and anticancer agent.     

Emblica officinalis improves glycemic status and oxidative stress in STZ induced type 2 diabetic model rats

Objective:To evaluate the antidiabetic and antioxidant potential of Emblica officinalis(E.officinalis)fruit on normal and type 2 diabetic rats.Methods:Type 2 diabetes was induced into the male Long-Evans rats.The rats were divided into nine groups including control groups receiving water,type 2 diabetic controls,type 2 diabetic rats treated with glibenclamide(T2GT)and type 2diabetic rats treated with aqueous extract of fruit pulp of E.officinalis.They were fed orally for8 weeks with a single feeding.Blood was collected by cutting the tail tip on 0 and 28 days and by decapitation on 56 day.Packed red blood cells and serum were used for evaluating different biochemical parameters.Results:Four weeks administration of aqueous extract of E.officinalis improved oral glucose tolerance in type 2 rats and after 8 weeks it caused significant(P0.007)reduction in fasting serum glucose level compared to 0 day.Triglycerides decreased by 14%but there was no significant change in serum ALT,creatinine,cholesterol and insulin level in any group.Furthermore,reduced erythrocyte malondialdehyde level showed no significant change(P0.07)but reduced glutathione content was found to be increased significantly(P0.05).Conclusions:The aqueous extract of E.officinalis has a promising antidiabetic and antioxidant properties and may be considered for further clinical studies in drug development.