Effect of flavonol glycoside in mulberry (Morus alba L.) leaf on glucose metabolism and oxidative stress in liver in diet‐induced obese mice

BACKGROUND: Mulberry therapies on type 2 diabetic patients or streptozotocin‐induced diabetic rats have been reported to improve fasting blood glucose levels. We investigated the effects of dietary consumption of mulberry‐leaf powder and purified quercetin 3‐(6‐malonylglucoside), the quantitatively major flavonol glycoside in mulberry leaves, on glucose and lipid metabolism in high‐fat diet‐induced obese mice. Male C57BL/6J mice aged 8 weeks were assigned to three groups (control, mulberry leaf powder (MLP), and quercetin 3‐(6‐malonylglucoside) (Q3MG)) and treated with their respective diets for 8 weeks. RESULTS: We found that dietary supplementation of 10 g MLP kg^?1 or 1 g Q3MG kg^?1 in high‐fat diet effectively suppressed blood glucose levels. We also noted increased expression of glycolysis‐related genes and suppression of thiobarbituric acid reactive substances concentrations in the liver of Q3MG group compared to control mice. CONCLUSION: Dietary consumption of Q3MG, the quantitatively major flavonol glycoside in mulberry leaves, improved hyperglycemia in obese mice and reduced oxidative stress in the liver. Copyright © 2010 Society of Chemical Industry     

双响应值联合优化药桑葚酵素发酵工艺及其抗氧化性的研究

以药桑葚为原料,探讨发酵工艺条件对酵素超氧化物歧化酶(SOD)活力和总酚等指标的影响。通过响应面双响应值联合分析确定药桑葚酵素混菌发酵最佳工艺条件并对产品的抗氧化性进行研究。结果表明,药桑葚酵素发酵工艺条件为最佳温度36℃,最佳时间16.4 h,接种量8.33×10⁶ CFU/mL,固形物添加量1.6°Brix。得到的药桑葚酵素中SOD活力为329 U/g,总酚含量为9.11 mg/g。随着药桑葚酵素浓度的增加,抗氧化性不断增强。发酵工艺的优化可以有效提高药桑葚酵素的SOD活力、总酚含量,从而有利于提高酵素的抗氧化性。     

海参精囊水提物对模型小鼠睾丸生精细胞凋亡及 Bcl-2和Bax表达的影响

目的 探讨海参精囊水提物对模型小鼠睾丸生精细胞凋亡的影响及相关蛋白的表达情况。方法 昆明种小白鼠72只随机分6组,除正常空白组用生理盐水外其他各组均腹腔注射环磷酰胺(CP,28mg/kg),每天1次,连续5天,复制睾丸生精障碍小鼠模型;同时治疗组每天灌胃不同剂量的药物1次,连续4周。用TUNEL法检测各组小鼠睾丸生精细胞的凋亡情况;用免疫组化的方法检测Bcl-2和Bax的表达,并与模型组进行比较。结果 海参精囊水提物能够抑制小鼠睾丸生精细胞的凋亡,使Bcl-2的表达增加,Bax的表达降低,与模型组比较有统计学意义(P<0.05、0.01)。结论 海参精囊水提物对环磷酰胺所致生精障碍模型小鼠的生精细胞凋亡有一定的抑制作用,其作用可能与调控Bcl-2和Bax的表达有关。     

桑椹籽中黄酮的CO2超临界流体萃取及抑菌作用研究

本文研究了CO2超临界流体萃取桑椹籽中总黄酮苷类化合物的影响因素,进行了生产工艺优化的正交试验,并对萃取物的抑菌作用进行了研究.结果表明,对萃取率影响主次次序为:萃取压力、萃取温度、CO2流量、夹带剂用量.生产最优工艺条件为:萃取压力30MPa、萃取温度为50℃、CO2流量20kg/h、夹带剂料液比为1:4.萃取物色泽金黄、无异味,每100g萃取物含总黄酮苷类化合物67.63mg.萃取物对细菌和霉菌都有一定的抑制作用,而对细菌的抑制作用较强.     

鼓槌石斛毛兰素诱导人结肠癌Caco-2细胞凋亡

目的:研究毛兰素对人结肠癌Caco-2细胞增殖的抑制作用及其诱导细胞凋亡的分子机制。方法:采用SRB法检测毛兰素对Caco-2细胞增殖的抑制作用,用Hoechst33342染色法观察细胞的形态学改变,流式细胞术检测细胞的凋亡率和细胞周期;蛋白免疫印迹法（Western Blot）检测细胞凋亡相关蛋白Caspase-3的表达水平。结果:与对照相比,毛兰素能抑制结肠癌细胞Caco-2的增殖,且抑制率随着药物浓度与时间增加,呈剂量时间效应,48 h半数抑制浓度IC50为0.845μg/m L;毛兰素能诱导Caco-2细胞凋亡,并诱导细胞周期阻滞于G₂期;Caspase-3活性裂解片段表达增高。结论:毛兰素对肿瘤细胞的增殖具有一定抑制作用且通过线粒体途径诱导Caco-2细胞凋亡。      

Effect of antioxidants on the apoptosis of CHO cells and production of tissue plasminogen activator in suspension culture

The effects of antioxidants on the apoptosis of Chinese hamster ovary (CHO) 1-15,500 cells and production of tissue plasminogen activator (tPA) in suspension culture were investigated. After cell growth to 2 x 10(5) cells/ml in Ham's F12 medium containing 10% newborn bovine serum (NBS) in a spinner bottle, CHO cells were maintained for 6 d in Ham's F12 medium containing 0 or 0.4% NBS and 10 mM antioxidants, namely, l-ascorbic acid 2-phosphate (VCP) or the reduced form of glutathione (GSH). The viable cell concentrations at day 6 in the serum-free culture with GSH and in the low-serum culture wiht VCP or GSH were 0.57, 1.04 and 1.69 x 10(5) cells/ml, respectively, while those in the serum-free and low-serum cultures without the antioxidants were only 2.33 and 1.17 x 10(3) cells/ml, respectively. The percentages of apoptotic cells in the serum-free and low-serum cultures with VCP (73.2, 44.6%) and GSH (76.9, 38.6%) measured using a flowcytometer after annexin V-FITC/propidium iodide staining were markedly lower than those in the cultures without antioxidants (96.3, 92.5%). The percentage of cells having a high mitochondrial membrane potential among the viable cells in the cultures with antioxidants determined using a flowcytometer after 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine iodide staining was clearly higher than those in the cultures without the antioxidants. The production of tPA in the serum-free and low-serum media with VCP (0.282, 2.92 mg/l) or GSH (1.01, 1.61 mg/l) was markedly higher than that in the cultures without the antioxidants (0.275, 0.689 mg/l). Consequently, the suppression of apoptosis through the maintenance of the membrane potential of mitochondria by VCP or GSH resulted in a marked increase in tPA production by CHO cells in the serum-free and low-serum cultures.     

小米抗氧化肽的纯化及其抑制H2O2诱导损伤的胰岛素瘤细胞氧化应激作用

本研究利用Sephadex G-25和DEAE-32对小米抗氧化肽进行纯化,利用醋酸纤维素薄膜电泳法测定小米抗氧化肽的纯度,以1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基、超氧阴离子自由基、羟自由基清除实验考察纯化的小米抗氧化肽对自由基的清除能力。在细胞水平研究小米抗氧化肽对胰岛细胞的保护作用,利用H2O2进行大鼠胰岛素瘤细胞（INS-1）氧化应激造模,采用2’,7’-二氯二氢荧光素二乙酸酯荧光探针法检测细胞内活性氧（reactive oxygenspecies,ROS）水平,3-（4,5-二甲基噻唑-2）-2,5-二苯基四氮唑溴盐法检测细胞活力,采用流式细胞技术检测细胞凋亡率,采用实时荧光定量聚合酶链式反应检测抗氧化酶的表达水平。结果表明：经过Sephadex G-25和DEAE-32两次层析,小米抗氧化肽达到了电泳纯;50 μg/mL小米抗氧化肽对超氧阴离子自由基、羟自由基和DPPH自由基的清除率分别为（62.71±3.86）%、（73.56±4.51）%和（82.62±5.25）%;小米抗氧化肽能显著提升H2O2损伤后细胞活力,降低细胞内ROS水平,抑制H2O2诱导损伤的INS-1细胞的凋亡（P＜0.05）,其可能的机制与超氧化物歧化酶1、过氧化氢酶、谷胱甘肽巯基转移酶、醌氧化还原酶1等抗氧化酶系的表达上调有关。结论：小米抗氧化肽对H2O2诱导损伤的INS-1细胞氧化应激具有一定的保护作用。     

麦麸结合态多酚对肝癌HepG-2细胞增殖及凋亡效应研究

目的 本文主要研究麦麸结合态多酚对肝癌HepG-2细胞的抑制效应。方法 小麦麸皮粉碎后,采用丙酮-碱消化法,获得麦麸结合态多酚物质,命名为：WBBP,用福林酚比色法测定该多酚的含量及提取得率;通过MTT法检测WBBP处理对肝癌HepG-2细胞增殖的抑制效应,倒置显微镜观察WBBP处理对HepG-2肝癌细胞形态学的影响;采用流式细胞仪检测WBBP处理对HepG-2肝癌细胞周期、凋亡情况以及线粒体膜电位的影响;利用caspases试剂盒检测WBBP作用下肝癌HepG-2细胞中Caspase-3、Caspase-8、Caspase-9的酶活性变化。结果显示,不同浓度的WBBP通过诱导HepG-2肝癌细胞周期在S期阻滞,显著抑制了细胞增殖,且具有浓度依赖性;同时WBBP通过caspase依赖的线粒体凋亡路径诱导HepG-2肝癌细胞凋亡率以浓度依赖的方式增加。结论 麦麸结合态多酚WBBP能够通过显著抑制HepG-2肝癌细胞的增殖,并诱导细胞凋亡来发挥抗肝癌效应。