Protective effect of Lycium barbarum polysaccharides on streptozotocin-induced oxidative stress in rats

Fruit from Lycium barbarum L. in the family Solanaceae is well-known in traditional Chinese herbal medicine. Lycium barbarum polysaccharides (LBP) have been identified as one of the active ingredients responsible for its biological activities. We isolated polysaccharides from dried Lycium barbarum fruits by boiling water extraction. In the study, 50 animals were divided into two groups: a nondiabetic control (n = 10) and a diabetic group (n = 40). Diabetes was induced by a single injection of streptozotocin (50 mg/kg BW; Sigma, USA) freshly dissolved in a 0.1 mol/L citrate buffer (pH 4.5) into the intraperitonium. The normal control rats and the untreated diabetic control rats were only injected with the citrate buffer. Treated diabetic rats were administrated with LBP in drinking water through oral gavage for 30 days. At the end of experiment, oxidative indice in blood, liver and kidney of all groups were examined. The results show that administration of LBP can restore abnormal oxidative indice near normal levels. Therefore, we may assume that LBP is effective in the protection of liver and kidney tissue from the damage of STZ-induced diabetic rats and that the LBP may be of use as a antihyperglycemia agent.     

Ganoderma lucidum polysaccharides supplementation attenuates exercise-induced oxidative stress in skeletal muscle of mice

The present study was designed to determine the effects of Ganoderma lucidum polysaccharides (GL-PS) on exhaustive exercise-induced oxidative stress in skeletal muscle tissues of mice. The mice were divided into four groups (three GL-PS administered groups and the control group). The control group was administered with distilled water and GL-PS administered groups were administered with GL-PS (50, 100 and 200 mg/kg body weight per day). After 28 days, the mice performed an exhaustive swimming exercise, along with the determination of superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT) activities and malondialdehyde (MDA) levels in the skeletal muscle of mice. The results showed that GL-PS could increase antioxidant enzymes activities and decrease the MDA levels in the skeletal muscle of mice. This study provides strong evidence that GL-PS supplementation possessed protective effects against exhaustive exercise-induced oxidative stress.     

一次性力竭运动致大鼠骨骼肌氧化应激的机制

目的:观察一次性力竭运动对大鼠骨骼肌氧化应激相关酶表达的影响。方法:雄性SD大鼠40只,分为4组(n=10),分别为对照组(C组)、力竭运动组(E组)、运动+PKC抑制剂组(EC组)、运动+NOX抑制剂组(EA组)。三组运动大鼠进行3 d的跑台适应性运动(5 m/min,1次/日,无坡度),然后休息1 d; EC组于运动前1 d和运动前1 h注射PKC抑制剂白屈菜红碱(5 mg/kg),EA组同期注射NADPH氧化酶抑制剂Apocynin(10 mg/kg),C组和E组注射同等剂量生理盐水;三组运动大鼠进行一次性跑台力竭运动,力竭后取大鼠的跖肌,DCF荧光探针检测活性氧(ROS),Western blot分析NOX2、NOX4、3-NT,免疫沉淀分析PKC、NOX2、NOX4。结果:与C组相比,E组的ROS水平、NOX2和NOX4蛋白表达、PKC-NOX2和PKC-NOX4复合物水平、3-NT生成均显著增加(P <0. 01,P <0.05),EC组、EA组ROS无显著差异(P>0.05),EC组NOX4蛋白表达显著增加(P<0.05);与E组相比,EC组和EA...     

Glycerogalactolipids from the fruit of Lycium barbarum

Four glycerogalactolipids (1-4), together with 11 other previously known homologues were isolated from the fruit of Lycium barbarum. Their structures were elucidated by chemical analyses including regio-selective enzymatic, alkaline and acidic hydrolyses and spectroscopic methods involving GCMS, HRESIMS and 1D and 2D NMR, respectively.     

The analysis of differential gene expression in early somatic embryogenesis on Lycium barbarum

Direct exposure of calluses of Lycium barbarum L. to an auxin-free medium can induce somatic embryogenesis. Somatic embryogenesis of Lycium barbarum L. is controlled artificially by regulating 2,4-D concentration. The total RNA that was isolated from calluses, embryonic calluses and early somatic embryos was used for analyzing differential genes expression. We obtained three cDNAs from early somatic embryogenesis which were not found in calluses. The results indicate that these cDNAs were early embryogenesis-specific cDNAs and this gene expression was induced in cultured calluses after a transfer to an auxin- free medium. A cDNA library was constructed using poly(A)⁺-RNA derived from early somatic embryos of Lycium barbarism L. Two full-length cDNAs were isolated from the library by differential screening. Northern blot hybridization analysis indicated that the expression of the full-length cDNA only existed in embryogenic calluses and early somatic embryos of Lycium barbarum L. This revised version was published online in June 2006 with corrections to the Cover Date.     

Protoplast culture and plant regeneration in Lycium barbarum L.

Protoplasts were isolated from leaves of the woody plant Lycium barbarum L. and cultured in liquid nutrient medium TM-2 at a density of 10⁴–10⁵ cells ml^-1. After ten days of culture, regenerated colonies were transferred to the agar-solidified medium TM-3, and 5–7 days later to regeneration media PRM or TM-4. Formation of shoots was observed after 30–40 days. Completely formed and rooted plants were transferred to the soil. Cytological and morphological analysis of the regenerated plants revealed relative genetic stability of this species in the process protoplast — plant. The results obtained allow us to conclude that L. barbarum can be used in the experiments on somatic hybridization or direct gene transfer.     

枸杞多糖的抗炎镇痛作用研究

为研究枸杞多糖的抗炎镇痛效应及其潜在分子机制,采用小鼠热板实验、小鼠福尔马林炎症疼痛模型和原代培养的背根神经节神经元细胞对疼痛指标和炎症相关分子进行了检测。实验结果显示枸杞多糖能显著缓解后足注射福尔马林引起的动物II相痛表现(P <0. 05),减少动物两后足重量差值(P <0. 001)和血液(P <0. 001)、脊髓(P <0. 05)组织中白细胞介素6的含量,而对小鼠热板潜伏期无明显影响;枸杞多糖降低原代培养的DRG细胞膜上TRPV1介导的钙信号(P <0. 05)。结果证明枸杞多糖具有良好的抗炎镇痛作用,其镇痛机制可能与降低炎症因子白细胞介素6表达及其引起的TRPV1活性增加有关。     

Factors affecting Agrobacterium tumefaciens-mediated genetic transformation of Lycium barbarum L.

Summary Using the system for genetic transformation and transgenic plant regeneration via somatic embryogenesis (SE) of Lycium barbarum established in this laboratory, this study reports the optimization of the factors affecting the efficiency of transformation, including pre-culture period, leaf explant source, use of acetosyringone, strains and density of Agrobacterium, and temperature of co-cultivation. The optimized transformation protocol for L. barbarum included preculture of leaf explants from 3-wk-old seedlings for 3 d on the medium for callus induction followed by inoculation with Agrobacterium strain EHA101 (pIG121 Hm), co-cultivation for 3d at 24&#x00B0;C, and transfer to the selection regeneration medium with 50 mg l^&#x2212;1 kanamycin (Kan). Using this protocol, 65% L. barbarum explants gave rise to Kan-resistant and GUS-positive calli. In addition, the expression of introduced transgene (npt II) in clonal progeny was verified by formation of calli and somatic embryos from leaf segments of nine transgenic plants grown on the Kan-containing medium. All explants formed calli at 50 mg l^&#x2212;1 Kan and seven out of nine transgenic plants were found to possess callus-forming capacity even at 100 mg l^&#x2212;1 Kan. These calli also possessed higher SE potential on SE medium supplemented with 25 mg l^&#x2212;1 Kan.     

Lycium barbarum polysaccharides: Protective effects against heat-induced damage of rat testes and H2O2-induced DNA damage in mouse testicular cells and beneficial effect on sexual behavior and reproductive function of hemicastrated rats

Lycium barbarum, a famous Chinese medicinal herb, has a long history of use as a traditional remedy for male infertility. Polysaccharides are the most important functional constituent in L. barbarum fruits. We systematically investigated the effect of L. barbarum polysaccharides (LBP) on rat testis damage induced by a physical factor (43 degrees C heat exposure), on DNA damage of mouse testicular cells induced by a chemical factor (H2O2), and on sexual behavior and reproductive function of hemicastrated male rats. The results showed that LBP provided a protective effect against the testicular tissue damage induced by heat exposure. When compared with negative control, a suitable concentration of LBP significantly increased testis and epididymis weights, improved superoxide dismutase (SOD) activity, and raised sexual hormone levels in the damaged rat testes. LBP had a dose-dependent protective effect against DNA oxidative damage of mouse testicular cells induced by H2O2. LBP improved the copulatory performance and reproductive function of hemicastrated male rats, such as shortened penis erection latency and mount latency, regulated secretion of sexual hormones and increased hormone levels, raised accessory sexual organ weights, and improved sperm quantity and quality. The present findings support the folk reputation of L. barbarum fruits as an aphrodisiac and fertility-facilitating agent, and provide scientific evidence for a basis for the extensive use of L. barbarum fruits as a traditional remedy for male infertility in China.     

Effects of acute exhaustive physical exercise upon glutamine metabolism of lymphocytes from trained rats

Transitory immunosupression is reported after intense exercise, especially after an increase in training overload and in overtraining. The influence of intense exercise on plasma hormones and glutamine concentration may contribute to this effect. However, the effect of such exercise-induced changes upon lymphocyte and glutamine metabolism is not known. We compared glutamine metabolism in lymphocytes in sedentary (SED) and trained rats. Rats from the moderate group (MOD) swam for 6 weeks, 1 h/day, in water at 32+/-1 degrees C, with a load of 5.5% body weight attached to the tail. Animals from the exhaustive group (EXT) trained like MOD, with training increasing to 3 times 1 h a day during the last week, with 150 min rest between each bout. Animals were killed immediately after the last training bout. We observed reduced concentrations of plasma glucose (p<0.05), glutamine (p<0.05), glutamate (p<0.05) in EXT compared to SED. In MOD, decreases in glutamine (p<0.05) were observed. Analyzing lymphocyte metabolism, we observed an increase in lactate production and glutamine consumption (p<0.05) in MOD (p<0.05) compared to SED and a decrease in glutamine consumption (p<0.05) and aspartate production in EXT. An increase in the proliferative response of lymphocytes in MOD and EXT was also observed when stimulated by ConA and LPS similarly to SED. Acute exercise promoted decreased glutamine plasma concentration and changes in glutamine metabolism that did not impair lymphocyte proliferation in exhaustive trained rats.     

Relation between oxidative stress markers and antioxidant endogenous defences during exhaustive exercise

Hydrogen peroxide (H₂O₂) could induce oxidative damage at long distance from its generation site and it is also an important signalling molecule that induces some genes related to oxidative stress. Our objective was to study the plasma and blood cells capability to detoxify H₂O₂ after intense exercise and its correlation with oxidative damage. Blood samples were taken from nine professional cycling, participating in a mountain stage, under basal conditions and 3 h after the competition. Catalase and glutathione peroxidase activities decreased (40 and 50% respectively) in neutrophils after the cycling stage, while glutathione peroxidase increased (87%) in lymphocytes. Catalase protein levels and catalase specific activity maintained basal values after the stage in plasma. Catalase protein levels decreased (48%) in neutrophils and its specific activity increased up to plasma values after exercise. Myeloperoxidase (MPO) increased (39%) in neutrophils after the cycling stage. Exercise-induced hemolysis and lymphopenia inversely correlated with cellular markers of oxidative stress. Plasma malondialdehyde (MDA) directly correlated with neutrophil MPO activity and erythrocytes MDA. Intense exercise induces oxidative damage in blood cells as erythrocytes and lymphocytes, but not in neutrophils.     

Relation between oxidative stress markers and antioxidant endogenous defences during exhaustive exercise

Hydrogen peroxide (H₂O₂) could induce oxidative damage at long distance from its generation site and it is also an important signalling molecule that induces some genes related to oxidative stress. Our objective was to study the plasma and blood cells capability to detoxify H₂O₂ after intense exercise and its correlation with oxidative damage. Blood samples were taken from nine professional cycling, participating in a mountain stage, under basal conditions and 3 h after the competition. Catalase and glutathione peroxidase activities decreased (40 and 50% respectively) in neutrophils after the cycling stage, while glutathione peroxidase increased (87%) in lymphocytes. Catalase protein levels and catalase specific activity maintained basal values after the stage in plasma. Catalase protein levels decreased (48%) in neutrophils and its specific activity increased up to plasma values after exercise. Myeloperoxidase (MPO) increased (39%) in neutrophils after the cycling stage. Exercise-induced hemolysis and lymphopenia inversely correlated with cellular markers of oxidative stress. Plasma malondialdehyde (MDA) directly correlated with neutrophil MPO activity and erythrocytes MDA. Intense exercise induces oxidative damage in blood cells as erythrocytes and lymphocytes, but not in neutrophils.     

Protective effect of a Potentilla anserine polysaccharide on oxidative damages in mice

Potentilla anserine polysaccharide (PAP) was studied in vivo to investigate its antioxidant activity using the model of dexamethasone-induced oxidative stress in mice. The investigation demonstrated that PAP at 50, 100 or 200 mg/kg body weight for 7 days respectively increased thymus index and spleen index, glutathione level, superoxidase dismutase activity and total antioxidant capacity in both thymus and spleen and decreased the content of H₂O₂ in spleen and NO in both thymus and spleen of mice. The results revealed that PAP was able to overcome dexamethasone-induced oxidative stress and might play an important role in repairs of oxidative damage in immunological system.     

Effect of aerobic exercise intervention on DDT degradation and oxidative stress in rats

Dichlorodiphenyltrichloroethane (DDT) reportedly causes extensively acute or chronic effects to human health. Exercise can generate positive stress. We evaluated the effect of aerobic exercise on DDT degradation and oxidative stress.Main methods: Male Wistar rats were randomly assigned into control (C), DDT without exercise training (D), and DDT plus exercise training (DE) groups. The rats were treated as follows: DDT exposure to D and DE groups at the first 2 weeks; aerobic exercise treatment only to the DE group from the 1st day until the rats are killed. DDT levels in excrements, muscle, liver, serum, and hearts were analyzed. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) levels were determined. Aerobic exercise accelerated the degradation of DDT primarily to DDE due to better oxygen availability and aerobic condition and promoted the degradation of DDT. Cumulative oxidative damage of DDT and exercise led to significant decrease of SOD level. Exercise resulted in consistent increase in SOD activity. Aerobic exercise enhanced activities of CAT and GSH-Px and promoted MDA scavenging. Results suggested that exercise can accelerate adaptive responses to oxidative stress and activate antioxidant enzymes activities. Exercise can also facilitate the reduction of DDT-induced oxidative damage and promoted DDT degradation. This study strongly implicated the positive effect of exercise training on DDT-induced liver oxidative stress.     

宁夏枸杞果实内源激素的变化及其与细胞壁成分和相关酶的关系

采用高效液相色谱技术, 研究了不同发育时期宁杞1号和宁杞5号枸杞(Lycium barbarum)果皮和种子内源激素(玉米素(ZT)、赤霉素(GA₃)、生长素(IAA)和脱落酶(ABA))含量与果实生长发育的关系。结果表明, 宁杞5号果实横纵径和单粒重均大于宁杞1号, 果实发育前期, 尤其是缓慢生长期, 是宁杞5号果实大小和重量积累的关键时期。宁杞1号种子中的生长素含量与果实横径和果实单粒重均呈极显著正相关, 与果实纵径呈显著正相关。宁杞5号果皮中玉米素含量与果实横径和单粒重均呈显著正相关, 种子中生长素含量与果实横径和单粒重均呈显著正相关。玉米素促进细胞的分裂, 而细胞数目比细胞体积对决定果实大小的作用更大; 在缓慢生长期(开花后8–25天), 宁杞5号果皮和种子中的脱落酸含量均显著小于宁杞1号。以上两点可能是宁杞5号的横纵径和单粒重均大于宁杞1号的主要原因。宁杞1号果皮中的GA₃与半纤维素酶(Cx)活性的变化相反, 说明宁杞1号果实发育前期和中期果皮中高含量的GA₃对细胞壁中Cx活性有一定的抑制作用, 从而表现出果实膨大。宁杞5号果皮中的IAA与多聚半乳糖醛酸酶(PG)和果胶酯酶(PE), ZT与PE, ABA与Cx, 种子中的ZT与PE的变化均相反, 说明宁杞5号果实发育前期和中期果皮中高含量的IAA、ZT、ABA及种子中的ZT可促进果实的膨大。推测这可能是宁杞5号果实单粒重大于宁杞1号的主要原因之一。宁杞5号果皮中的ZT和种子中的IAA可以增强Cx的活性; 宁杞1号果皮中的ABA可以增强PE的活性, 进而促进果实的成熟。