维生素C和E对染铅大鼠海马抗氧化酶及NO与NOS的影响

目的：观察维生素C、E对五周龄生长期染铅SD大鼠血铅及海马超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH—Px）、NOS活性及丙二醛（MDA）、NO含量的影响。方法：大鼠自由饮用0．615mmol／L的醋酸铅4周造成铅中毒模型。然后以维生素C100mg／kg、维生素E100mg／kg单独或联合灌胃1周。测量血铅水平，大鼠海马组织SOD、GSH—Px、NOS活性及MDA和NO含量。结果：与铅模型组比较，给予维生素C，维生素E后，大鼠血铅浓度显著性降低（P〈0．05）；MDA含量下降，且其联合治疗组与单独维生素C治疗组差异有显著性（P〈0．05）；SOD，GSH—Px、NO、NOS水平显著高于铅模型组，差异有显著性（P〈0．05）。结论：补充维生素C、维生素E可以降低血铅含量，减轻铅中毒引起的海马的脂质过氧化损伤，提高NOS、NO活性。     

缺血后处理对鼠肺缺血-再灌注损伤中氧化状态的影响

目的 研究缺血后处理对于肺缺血-再灌注损伤早期内源性氧化/抗氧化系统及一氧化氮水平的影响.方法 24只雄性SD大鼠,分为假手术组(S),缺血-再灌注组(I/R)以及缺血后处理组(IPO)(每组8只),分别检测肺组织中谷胱甘肽(GSH)、丙二醛(MDA)及一氧化氮(NO)的水平;黄嘌呤氧化酶(XO)及髓过氧化物酶(MPO)的活性;抗氧化酶包括:超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化酶(GPX)的活性.结果 IPO组与I/R组相比较,其抗氧化系统:SOD(41.4±4.4)U/mg vs(19.6±2.8)U/mg、CAT(19.5±1.6)U/mg vs(8.4±0.8)U/mg、GPX(168±13)U/mg vs(72±8)U/mg)和GSH(1.72±0.26)mg/g vs(0.89±0.07)mg/g蛋白的水平明显升高(均P＜0.05);氧化状态指标:XO(50±6)U/g vs(83±8)U/g,MPO(5.0±0.5)U/g vs(7.6±0.7)U/g和MDA(0.91±0.08)nmol/mg vs(1.58±0.17)nmol/mg的水平显著降低(均P＜0.05);并且内源性NO[(93±7)μmoL/g vs(22±4)μmol/g]的水平也明显升高(P＜0.01).结论 在再灌注初期的后处理可以减轻肺缺血-再灌注损伤,其保护作用一定程度上是通过抑制氧化剂的产生以及氧化作用,并且内源性NO也许和后处理的保护作用有关.     

五味子抗氧化作用研究

目的优化五味子抗氧化物的提取条件;分析湖北产和辽宁产五味子提取物的DPPH清除能力。方法以DPPH自由基的清除能力为参考指标,采用单因素实验的方法,考察溶剂种类、乙醇浓度、料液比、提取时间、提取次数和提取方法等因素对五味子提取物抗氧化作用的影响。结果五味子抗氧化物的最优提取条件为:以60%的乙醇为提取溶剂,超声法提取,料液比为1∶30(g·m L-1),提取次数3次,每次提取20min,室温提取;湖北产和辽宁产五味子提取物清除DPPH自由基的IC50分别为3.79mg·m L-1和7.60mg·m L-1。结论五味子提取物具有较强的抗氧化作用,且湖北产五味子提取物的抗氧化作用比辽宁产五味子的强。     

Antioxidative and anticancer activities of various ethanolic extract fractions from crown-of-thorns starfish (Acanthaster planci)

Many studies currently researching marine invertebrates to determine the therapeutic potential of their bioactive materials have been showing very promising results. The crown-of-thorns starfish Acanthaster planci, an Echinodermata of the class Asteroidea, is infamous as the unique venomous starfish and as a destroyer of coral reefs. Starfish possesses many useful pharmacological and biological characteristics. In this study, A. planci was extracted with 70% ethanol and lyophilized to obtain an ethanol fraction. The ethanol fraction was dissolved with water and defatted with petroleum ether to obtain a non-polar fraction. The residual solution was successively partitioned with ethylacetate and butanol to obtain an ethylacetate fraction and butanol fraction, respectively. Four fractions were used to examine the antioxidant and anticancer properties. The ethanol fraction of A. planci contained the highest antioxidant effects such as ABTS, DPPH, Fe²⁺ chelating activity and reducing power when compared with four fractions. Among the four fractions, the butanol fraction was especially shown to inhibit human malignant melanoma A375.S2 cells’ proliferation, which is involved in the apoptotic progression. This fraction could induce apoptosis and even necrosis in A375.S2 cells as evidenced by double staining with an Annexin V-FITC and PI assay and DNA fragmentation analysis. These results indicated that the starfish A. planci is a good resource for obtaining the biologically active substances for antioxidant and anticancer effects.     

Effects of cooking on in vitro sinigrin bioaccessibility,total phenols,antioxidant and antimutagenic activity of cauliflower (Brassica oleraceae L. var. Botrytis)

Cauliflower (Brassica oleraceae L. var. Botrytis) is a good source of bioactive compounds, such as glucosinolates, phenolic compounds and vitamins. In this study, the effects of some processes (i.e. boiling, steaming) on the sinigrin bioaccessibility as a major glucosinolate found in cruciferous vegetables after in vitro digestion, also in vitro antimutagenic activities, total phenols and total antioxidant capacities of cauliflower were determined. The sinigrin content was reduced by approximately 9.6% and 29.1% in steamed and boiled cauliflower (p > 0.05), respectively. After in vitro simulated digestion, sinigrin content was decreased by 26.4% in raw samples, increased by 29.5% and 114.7% in steamed and boiled samples, respectively. In all samples, mutagenic effect to Salmonella typhimurium TA 100 was not seen. When samples were steamed, phenol content was increased by 14.83%. After boiling total phenol content of cauliflower was decreased by 1.8%. Total antioxidant capacities (TAC) measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3 ethylbenzothiazoline-6-sulfonic acid) (ABTS) methods were increased by 47% and 39%, respectively (p < 0.05) in steamed samples and decreased by 8% and 7% with boiling, respectively (p > 0.05). TAC in raw sample of cauliflower, which was investigated in phosphomolybdenum assays, was determined as 18.7 mg ascorbic acid equivalents (AAE)/100 g. In all cases, the highest antioxidant activity was determined in the steamed samples, while the lowest antioxidant activity was in boiled samples.     

Cofactor metals and antioxidant enzymes in cisplatin-treated rats: effect of antioxidant intervention

We explored the association between the activities of antioxidant enzymes and their metallic cofactors in rats treated with cisplatin. The antioxidant effects of aminoguanidine, and a combination of vitamins E and C were investigated. Plasma platin was significantly lower than liver and kidney. Cisplatin treatment caused significant increase in plasma Se-glutathione peroxidase activity. Activities of Se-glutathione peroxidase, glutathione S-transferase, catalase and Cu,Zn-superoxide dismutase have been found to be significantly decreased in liver and kidney compared to controls. Zn levels in these organs were diminished upon cisplatin treatment, while levels of Cu were unaffected. Interestingly, levels of iron, the cofactor of catalase, were found to be significantly increased in liver and kidney. Intervention with aminoguanidine or vitamins was generally prevented cisplatin-caused changes in the activity of enzymes and in the tissue levels of cofactor metals. These observations suggest that relation between activities of enzymes and levels of cofactor metals is multifactorial.     

Efficacy study of two novel hyaluronic acid-based formulations for viscosupplementation therapy in an early osteoarthrosic rabbit model

Viscosupplementation (VS) is a therapy for osteoarthrosis (OA) consisting of repetitive intra-articular injections of hyaluronic acid (HA). It is known to be clinically effective in relieving pain and increasing joint mobility by restoring joint homeostasis. In this study, the effects of two novel HA-based VS hydrogel formulations were assessed and challenged against a pure HA commercial formulation for the first time and this in a rabbit model of early OA induced by anterior cruciate ligament transection (ACLT). The first formulation tested was a hybrid hydrogel composed of HA and reacetylated chitosan, a biopolymer considered to be chondroprotective, assembled thanks to an ionic shielding. The second formulation consisted of a novel HA polymer grafted with antioxidant molecules (HA-4AR) aiming at decreasing OA oxidative stress and increasing HA retention time in the articulation.ACLT was performed on rabbits in order to cause structural changes comparable to traumatic osteoarthrosis. The protective effects of the different formulations were observed on the early phase of the pathology in a full randomized and blinded manner. The cartilage, synovial membrane, and subchondral bone were evaluated by complementary investigation techniques such as gross morphological scoring, scanning electron microscopy, histological scoring, and micro-computed tomography were used.In this study, ACLT was proven to successfully reproduce early OA articular characteristics found in humans. HA and HA-4AR hydrogels were found to be moderately protective for cartilage as highlighted by μCT. The HA-4AR was the only formulation able to decrease synovial membrane hypertrophy occurring in OA. Finally, the hybrid HA-reacetylated chitosan hydrogel surprisingly led to increased subchondral bone remodeling and cartilage defect formation. This study shows significant effects of two innovative HA modification strategies in an OA rabbit model, which warrant further studies toward more effective viscosupplementation formulations.