Metabolic indicators of oxidative stress correlate with haemichrome attachment to membrane, band 3 aggregation and erythrophagocytosis in beta-thalassaemia intermedia

Haematological data, genotype, transfusion requirements, metabolic indicators of oxidative stress (flux via hexose-monophosphate shunt (HMPS); steady state level of GSH and GSSG, NADPH and NADP; activity of anti-oxidant enzymes), parameters of membrane damage (aggregated band 3; membrane-bound haemichromes, autologous immunoglobulins (Igs) and C3 complement fragments) and erythrophagocytosis were measured in erythrocytes (RBC) of 15 beta-thalassaemia intermedia patients (nine splenectomized) with low, if any, transfusion requirements. Patients presented increased aggregated band 3, bound haemichromes, Igs and C3 complement fragments, and increased erythrophagocytosis. Bound haemichromes strongly correlated with aggregated band 3. Anti-band 3 Igs were predominantly associated with aggregated band 3. Erythrophagocytosis positively correlated with aggregated band 3, haemichromes and Igs, suggesting the involvement of haemichrome-induced band 3 aggregation in phagocytic removal of beta-thalassaemic RBC. Splenectomized patients showed higher degrees of membrane damage and phagocytosis, significantly higher numbers of circulating RBC precursors, and tendentially higher numbers of reticulocytes. Basal flux via HMPS was increased twofold, but HMPS stimulation by methylene blue was decreased, as was the glucose flux via HMPS. GSH was remarkably decreased, whereas NADPH was increased. Except for unchanged catalase and glutathione reductase, anti-oxidant enzymes had increased activity. Negative correlation between HMPS stimulation by methylene blue and bound haemichromes indicated that the ability to enhance HMPS may counteract haemichrome precipitation and limit consequent membrane damage leading to erythrophagocytosis.     

Limoniastrum guyonianum methanol extract induces immunomodulatory and anti-inflammatory effects by activating cellular anti-oxidant activity

Evaluation of the immunomodulatory activity of plant extracts is an interesting and growing area of research. In this study, effects of a methanolic extract of Limoniastrum guyonianum stems (M extract) on mice immune cell function in vitro were investigated. These studies showed that mitogen-induced lymphocyte proliferation was dose-dependently inhibited by the extract. Further, the lectin-induced response appeared to be more sensitive to the suppressive effects of the extract than were LPS-stimulated responses. In studies to assess any potential effects of extract on innate immunity, the results showed that the extract significantly enhanced the killing activity of isolated NK cells. In addition, studies here demonstrated that the extract could enhance lysosomal enzyme activity and inhibit nitrite oxide (NO) production by murine peritoneal macrophages ex vivo, suggesting a potential anti-inflammatory effect in situ. The anti-inflammatory activity was concomitant with the cellular anti-oxidant effect in macrophages and splenocytes.     

Spicy Bitumen: Curcumin Effects on the Rheological and Adhesion Properties of Asphalt

Over the years, the need for the synthesis of biodegradable materials has facilitated the drift of the asphalt industry towards eco-sustainable and cost-effective production of road pavements. The principal additives in the asphalt industry to improve the performance of road pavements and increase its lifespan are majorly rheological modifiers, adhesion promoters and anti-oxidant agents. Rheological modifiers increase physico-chemical properties such as transition temperature of asphalt binder (bitumen), adhesion promoters increase the affinity between binder and stone aggregates while anti-oxidant agents reduce the effects of oxidation caused by exposure to air, water and other natural elements during the production of asphalt pavements. In this study, we tested the effectiveness of a food grade bio-additive on these three aforementioned properties. We also sought to hypothesize the mechanisms by which the additive confers these desired features on bitumen. We present this study to evaluate the effects of turmeric, a food-based additive, on bitumen. The study was conducted through dynamic shear rheology (DSR), atomic force microscopy, scanning electron microscopy (SEM) and boiling test analysis.     

HPLC-DPPH评价剑叶龙血树中抗氧化活性成分及构效关系

目的采用HPLC-DPPH法评价剑叶龙血树主要成分的抗氧化活性并分析其构效关系。方法采用HPLC法测定剑叶龙血树中自藜芦醇、龙血素A、龙血素B、紫檀芪、7,4′-二羟基黄酮,色谱条件:PhenomenexluraC_(18)(250mmn×4.6mmn,5μm)色谱柱,甲醇-乙腈-0.2%磷酸溶液梯度洗脱,体积流量1.0 mL/min,柱温35℃,检测波长306 nm。通过对比剑叶龙血树药材溶液加1,1二苯基-2-三硝基苯肼自由基(DPPH)反应前后的各化合物色谱峰面积衰减情况,以各化合物峰面积比值计算清除率,评价各化合物抗氧化活性。结果二苯乙烯类、二氢查耳酮类成分为剑叶龙血树中主要抗氧化活性成分;抗氧化能力强弱依次为紫檀芪(清除率73.19%)白藜芦醇(清除率71.10%)龙血素B(清除率39.01%)龙血素A(清除率12.14%)。从构效关系上分析,二苯乙烯类化合物,当羟基甲基化后,其抗氧化能力并未减弱;二氢查耳酮类化合物,苯环上甲氧基取代成对称结构有助于发挥其抗氧化能力;而仅有C7,4′位羟基取代的黄酮类化合物未显示抗氧化活性。结论建立的HPLC-DPPH评价方法能量化表达剑叶龙血树中主要抗氧化成分,为筛选药效指标成分及建立全面谱效相关质量标准奠定基础。     

Oral Astaxanthin Supplementation Prevents Peritoneal Fibrosis in Rats

♦ Background:

Preventing peritoneal damage during peritoneal dialysis is critical. Reactive oxygen species (ROS) have an important role in peritoneal damage; however, few studies have investigated this. We aimed to determine the effects of oral astaxanthin (AST) supplementation in a peritoneal fibrosis (PF) rat model.

♦ Methods:

Thirty-seven Sprague–Dawley rats were divided into 5 groups: Control 1 (fed a normal diet without stimulation), Control 2 (fed an AST-supplemented diet without stimulation), Group 1 (fed a normal diet with 8% chlorhexidine gluconate [CG] stimulation for 3 weeks), Group 2 (fed a 0.06% AST-supplemented diet with CG stimulation), and Group 3 (fed a 0.06% AST-supplemented diet that was initiated 4 weeks before CG stimulation). Peritoneal fibrosis, vascular proliferation, and fibrosis-related factor expression were examined.

♦ Results:

Peritoneal thickness was significantly suppressed by AST supplementation. Astaxanthin diminished the number of CD68-, 8-hydroxy-2′-deoxyguanosine (8-OHdG)-, and monocyte chemoattractant protein-1 (MCP-1)-positive cells. Type 3 collagen, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and MCP-1 mRNA expression was significantly lower in Group 3 than in Group 1. Increased transforming growth factor-β (TGF-β) and Snail mRNA expression, vascular density, and the number of α-smooth muscle actin (α-SMA)-positive cells were also decreased in Group 3.

♦ Conclusion:

Astaxanthin suppressed PF development through the inhibition of inflammation and oxidation in PF rats. It appears that the anti-oxidative agent AST may be useful for the prevention of peritoneal damage.     

Total anti-oxidant capacity of cell culture media

1. The composition of synthetic cell culture media is important for the behaviour of cultured cells in vitro and may affect the results of many in vitro experiments. The total anti-oxidant capacity (TAC) of an extracellular medium may be an important factor in cell redox homeostasis. 2. In the present study, the TAC of cell culture media used for the cultivation of mammalian, yeast and bacterial cells (RPMI1640, Iscove's modified Dulbecco's medium, Dulbecco's modified Eagle's medium, minimum essential medium Eagle's 1959 with Earle's salts, Parker medium 199 with Hanks salts, bacterial Luria-Bertani medium, yeast extract-peptone-glucose and yeast nitrogen base media) was estimated using the 2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS(.+)) decolourization assay and the ferric ion reducing anti-oxidant power assay. 3. We found that components of the media such as cysteine, tyrosine, tryptophan and Phenol Red are important contributors to the TAC of cell culture media.     

Comparison of the effects of vitamin E and/or quercetin in attenuating chronic cyclosporine A-induced nephrotoxicity in male rats

1. The aim of the present study was to investigate the effects of vitamin E and/or quercetin (Q) on renal function, oxygen radical concentrations in the kidney and some anti-oxidant enzyme activities in rats treated with cyclosporine A (CsA). 2. Groups of rats (270 +/- 15 g), on standard rat chow and water, received all their treatments by gavage for either 4 or 8 weeks. Control groups received either olive oil (0.5 mL) or 25% ethanol (0.5 mL) + olive oil (0.5 mL) per day as vehicle. All experimental groups received 25 mg CsA/kg per day in 0.5 mL olive oil. The vitamin E group received 100 mg vitamin E/kg per day in olive oil in addition to CsA treatment. The quercetin group received 15 mg of Q/kg per day in 0.5 mL of 25% ethanol in addition to CsA treatment. The vitamin E + quercetin group received the two anti-oxidants at the concentrations given in addition to CsA treatment. 3. Quercetin, at a concentration less than one-quarter of vitamin E, was more efficient in lowering blood urea nitrogen, serum creatinine and kidney malondialdehyde in CsA-treated rats. However, neither of the two anti-oxidants was able to normalize these analytes to control values after either 4 or 8 weeks treatment. 4. Quercetin (50 micromol/kg per day) elevated all renal anti-oxidant enzyme activities to values observed in the negative controls. However, vitamin E (232 micromol/kg per day) only normalized glutathione peroxidase activity at the end of either 4 or 8 weeks treatment. Combination treatment with the two anti-oxidants abolished all the ill-effects of CsA. 5. Combination treatment with the two anti-oxidants of renal transplant patients receiving CsA may be beneficial in ameliorating the chronic nephrotoxic effects of the important immunosuppressive drug CsA.     

Ameliorative effect of Chlorophytum borivilianum root on lipid metabolism in hyperlipaemic rats

1. The present study examined the efficacy of Chlorophytum borivilianum root (powder) in modulating the hyperlipaemic/hypercholesteraemic conditions in male albino rats. 2. Administration of C. borivilianum (0.75 and 1.5 g root powder/rat per day for 4 weeks) to hypercholesteraemic rats significantly increased high-density lipoprotein-cholesterol levels and decreased plasma and hepatic lipid profiles. 3. In addition, there were significant increases in faecal cholesterol, neutral sterol and bile acid excretion with elevated hepatic 3-hydroxy-3-methylglutaryl coenzyme A reductase activity and bile acid production. 4. Furthermore, the hypercholesteraemic rats treated with both doses of C. borivilianum also exhibited increases in superoxide dismutase and ascorbic acid levels. 5. Normocholesteraemic animals treated with both doses of C. borivilianum root powder did not show any significant variation in either lipid or anti-oxidant profiles, except for an increase in the hepatic ascorbic acid concentration compared with their untreated counterparts. 6. The hypolipaemic/hypocholesteraemic effect of C. borivilianum root powder appears to be mediated by an increase in cholesterol turnover via increased faecal cholesterol excretion and, second, through an endogenous cholesterol conversion into bile acid. 7. Administration of C. borivilianum root powder also increased the activities of anti-oxidant enzymes and vitamin C levels, which may have enhanced the anti-oxidant capacity of the liver.     

多指标综合评价玉竹蜜蒸炮制工艺研究

目的 优选玉竹蜜蒸炮制工艺.方法 兼顾多糖、皂苷、黄酮、醇提物、水提物和水分各指标的量及抗氧化活性,研究蜜润时间、料液比(炼蜜-玉竹)、蜜蒸时间、蜜蒸温度对各指标的影响,采用多指标综合评分法,利用正交试验优化玉竹的蜜蒸炮制条件.结果 在蜜润时间为2h,料液比(炼蜜-玉竹)为1∶4,蜜蒸时间1h,蜜蒸温度70℃条件下,综合得分为84.07,与未炮制玉竹相比,多糖、皂苷、醇提物、水提物的量分别提高了32.02％、206.95％、55.60％、48.78％,水分和黄酮的量稍有下降.结论 该方法有效提高了玉竹各指标的提取率,提高了玉竹的利用价值.     

绿茶多酚抗氧化作用及其机制研究进展

绿茶多酚是绿茶中儿茶素类、黄酮类、酚酸类和花色素类化合物的总称。研究发现,绿茶多酚具有抗氧化、减轻自由基损伤、降血脂、预防动脉粥样硬化和心血管疾病等多种生物学作用。本文对近年来绿茶多酚抗氧化作用及其机制,包括清除氧自由基、金属螯合作用、诱导Ⅱ期解毒酶的活化、抑制氧化还原敏感性的转录因子、抑制“促氧化”酶的活化等方面的研究进展作一综述。