大气CO2浓度倍增及UV B辐射对冬小麦幼苗生长发育及抗氧化特性的影响

为给未来气候环境下小麦育种和栽培提供依据,以鲁麦14为材料,在人工模拟条件下研究了大气CO₂浓度倍增和UVB辐射对冬小麦幼苗生长发育和抗氧化特性的影响。结果显示,大气CO₂浓度倍增可增加冬小麦株高、比叶重、地上部干重和分蘖数,显著提高抗氧化酶活性和类黄酮含量,降低了细胞膜透性;而高剂量的UVB处理效应与此相反。在高CO₂浓度和UVB复合处理下,CO₂倍增通过提高抗氧化酶活性,增加类黄酮含量,修复膜过氧化损害,明显减缓由高剂量UVB辐射对冬小麦的不利影响,有利于小麦幼苗生长发育。说明高浓度CO₂可以缓解UVB辐射对冬小麦幼苗生长产生的负效应。     

葡萄汁抗氧化作用的研究

[目的]探讨葡萄汁的抗氧化作用。[方法]取新鲜去皮去籽的红葡萄果肉榨取鲜葡萄果汁,通过DPPH法、邻苯三酚自氧化法、Fenton反应、烷基自由基引发的亚油酸氧化体系法分别测定不同浓度葡萄溶液的总抗氧化能力和清除超氧阴离子自由基、羟自由基、烷基自由基的能力。[结果]葡萄溶液对DPPH·的清除作用随其试验浓度增加而逐渐增大,IC50在高浓度（0．5mg／ml）时,葡萄溶液对DPPH·的最大清除率为90．51％,与对照VC相当;IC50在高浓度时,葡萄溶液对超氧阴离子自由基的最大清除率为73．40％;所有试验浓度的葡萄溶液对清除羟自由基的能力均明显高于VC,最高能达到86．24％;IC50在0．4～0．5mg／ml时,葡萄溶液具有一定的烷基自由基清除能力,可达50．77％,但其清除能力略低于Vc。[结论]葡萄具有很好的抗氧化作用。     

二色补血草黄酮的提取工艺及抗氧化功能研究

[目的]研究二色补血草黄酮的抗氧化功能及其最佳提取工艺。[方法]采用超声-微波协同法及L9（3^4）正交试验设计优化二色补血草黄酮的提取工艺,利用羟自由基抑制和油脂抗氧化试验判断二色补血草中黄酮的抗氧化功能。[结果]二色补血草中黄酮的最佳提取工艺为：乙醇浓度40%,料液比1∶50,温度50℃,提取时间20 min;此条件下提取量为50.97 mg/g。二色补血草黄酮类提取物对羟自由基.OH有明显的清除作用,并可抑制油脂的酸败,且作用效果随着浓度的增加而增强。[结论]该研究为二色补血草的综合开发和在保健食品及医药工业中的应用提供理论依据。     

家蚕雌蛾粉对四氧嘧啶模型小鼠抗氧化水平的影响

为明确家蚕雌蛾的药用价值,采用腹腔注射四氧嘧啶法建立抗氧化模型小鼠,灌胃给予不同剂量的家蚕雌蛾粉,通过对小鼠血清及肝脏的超氧化物歧化酶(SOD)、丙二醛(MDA)、谷胱甘肽过氧化物酶(GSH-Px)等生化指标测定,研究家蚕雌蛾粉的体内抗氧化作用。结果表明家蚕雌蛾粉可明显降低模型小鼠血清及肝脏的MDA含量,高剂量组(8 g/kg)的MDA含量降低至正常对照组的水平,家蚕雌蛾粉还可提高模型小鼠血清及肝脏的SOD、GSH-Px活性,中剂量(4 g/kg)、高剂量组的提高幅度达极显著水平。实验结果提示家蚕雌蛾粉具有明显的体内抗氧化作用。     

Bioactive 2-arylbenzofuran derivatives from Morus wittiorum

Investigation of an ethanol extract from the stem bark of Morus wittiorum led to the isolation of five new 2-arylbenzofuran derivatives that were named wittifuran S, wittifuran T, wittifuran V, wittifuran W and wittifuran X (1–5). Structures were determined on the basis of spectroscopic analysis. Two new wittifurans and five previously isolated compounds were assayed for antioxidant and anti-inflammatory activity.     

大麦多酚的提取工艺及功能研究进展

多酚是一类植物中普遍存在的次级代谢物质,在抗氧化、抗癌、抗衰老、降血糖、降血脂、预防心血管疾病等方面具有一定独特生理功效。大麦是多酚含量较高的谷物之一,总酚含量高达1 200~1 500 mg/kg,包含儿茶酸、原花青素聚合物等多种酚类化合物,已成为天然抗氧化剂开发的重要来源之一。本文结合研究工作,综述了大麦多酚的种类和含量,提取和测定方法,以及大麦多酚的抗氧化性能在动物饲料、啤酒酿造、人类健康等方面的应用研究进展。     

草本植物对铬污染的响应

采用人工模拟盆栽试验研究了重金属Cr6+胁迫对白花三叶草(Trifolium repens)、高羊茅(Festucaarundinacea)、紫花苜蓿(Medicago sativaL.)株高、丙二醛含量、超氧化物歧化酶(SOD)和过氧化物酶(POD)含量的影响。结果表明,3种草本植物对重金属Cr6+的耐受能力不同,白花三叶草耐性最强,紫花苜蓿的耐性最弱。Cr6+胁迫导致3种植物的生长均受到抑制。随Cr6+污染质量分数增加,3种植物的叶绿素含量和叶绿素a/叶绿素b比值都呈下降的趋势;MDA含量呈递增的趋势;SOD活性普遍降低;POD活性明显低于对照。     

大麻二酚对Cd和Cr胁迫下烟草生长的影响

为探讨大麻二酚(CBD)对重金属胁迫下烟草生长的影响,以烟草品种K326为材料,分别将浓度为0.0、1.0、5.0、25.0mg/L的CBD喷施于Cd和Cr胁迫烟株叶面,测定其叶片的抗氧化指标、生物量及Cd、Cr积累量。结果表明,Cd和Cr胁迫严重抑制烟株生长,显著提高烟叶活性氧和重金属含量。外源CBD对烟株生长存在低促高抑作用。当CBD浓度分别为1.0mg/L(Cd)和5.0mg/L(Cr)时效果最佳,显著降低了烟叶超氧阴离子(O₂^-·)产生速率,丙二醛、H₂O₂和烟株Cd、Cr含量;显著提高烟株干重、叶片超氧化物歧化酶、过氧化物酶、多酚氧化酶、抗坏血酸过氧化物酶和谷胱甘肽还原酶活性,增加抗坏血酸(As A)、谷胱甘肽(GSH)含量以及As A/DHA(氧化型抗坏血酸)、GSH/GSSG(氧化型谷胱甘肽)。综上,适量CBD能有效缓解Cd和Cr胁迫对烟叶的氧化损伤,抑制烟株内重金属的积累,促进植株生长。     

Antioxidant and serum lipid lowering effects of luffa cylindrical on experimental hyperlipidemia mice

AIM: To observe the antioxidation and the serum lipid lowing effects of polyphenols in luffa cylindrical on experimental hyperlipidemia mice. METHODS: Acetone was used to extract polyphenols from luffa cylindrical. The content of polyphenols was determined by Folin-ciocalteau method. The inhibitory efficacy of the extracts from luffa cylindrical to the production of OH· free radical was measured. Kunming mice were used to establish the hyperlipidemia model by feeding high fat diet. The freeze-dried fresh luffa cylindricals was added to the treated animals, xuezikang was also used as a positive control. After feeding high-fat food for 14 days, serum were collected to measure the total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C) and superoxidedismutase (SOD). The liver tissue was also collected for determining malonaldehyde (MDA) content. RESULTS: (1) Content of polyphenols in fresh luffa cylindrical was （0.3±0.1）g /kg. (2) The polyphenol extracts from fresh luffa cylindrical had a strong efficacy to inhibit the production of OH· free radicals. (3) The trend of body weight gain in groups LC1 (low dosage luffa cylindrical) and LC2 (high dosage luffa cylindrical) became slow down obviously, compared with that in group HPL (high-lipid model). (4) The levels of TC (4.19±0.37)mmol/L and LDL-C (2.77±0.79)mmol/L in group LC1, TC (3.56±0.55)mmol/L and LDL-C (2.34±0.41)mmol/L in group LC2, TC (4.59±0.96)mmol/L and LDL-C (3.25±0.67)mmol/L in group PC (positive control) were all lower than those in group HPL(P<0.01), which the decrease in the levels of TC and LDL-C in group LC2 was the most obvious. (5) SOD levels in the serum of mice in groups LC1 and LC2 were (337.00±29.73)U/mL and (349.00±9.99)U/mL respectively, which were higher than those in groups HPL and blank control, therein the SOD level in group LC2 increased obviously(P<0.01) compared with group HPL. The MDA levels in liver tissue in group LC2 was lower than those in control. CONCLUSION: Polyphenols in the luffa cylindrical are comparatively strong antioxidant. They effectively decrease the liver index and serum lipid in experimental mice.     

裂盖马鞍菌甲醇提取物清除自由基活性的研究

采用DPPH法、水杨酸法、邻苯三酚自氧化法分别测定裂盖马鞍菌甲醇提取物清除DPPH自由基、羟自由基和超氧自由基的能力。结果表明,在实验条件下,裂盖马鞍菌甲醇提取物对超氧阴离子、羟自由基、DPPH自由基均有不同程度的抑制作用,最高清除活性分别达72.72%、54.90%、92.08%。因此裂盖马鞍菌甲醇提取物具有一定的体外抗氧化活性。