左归降糖清脂方对2型糖尿病转基因MKR 鼠脂肪肝发生的影响

目的:探讨左归降糖清脂方对2型糖尿病转基因MKR鼠脂肪肝发生的影响。方法:30只MKR鼠随机分为MKR组、MKR高脂组和左归降糖清脂方组;左归降糖清脂方组以生药29.64 g.kg-1 ig干预治疗高脂饮食诱发脂肪肝的MKR鼠,观察其肝脏病理形态、血糖、血胰岛素、肝功能和血脂变化。结果:高脂饲料诱发MKR鼠形成非酒精性脂肪肝,肝细胞有大小不一的脂滴,呈脂肪性变;MKR高脂组小鼠空腹血糖、血胰岛素、肝质量、肝指数、肝功能指标[谷丙转氨酶(ALT),谷草转氨酶(AST)]、血清总胆固醇(TCHO)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C)高于MKR组(P<0.05,P<0.01),甘油三酯(TG)下降,低于MKR组(P<0.01)。2型糖尿病并发脂肪肝MKR鼠经左归降糖清脂方治疗后,肝细胞内脂肪性变得到改善,空腹血糖、血胰岛素、肝质量、肝指数、肝功能指标(ALT,AST)和血脂(TCHO,LDL-C和TG)显著下降,低于MKR小鼠(P<0.05,P<0.01);HDL-C高于MKR小鼠(P<0.05)。结论:左归降糖清脂方可通过调节高脂饮食MKR鼠体内的糖脂代谢,改善肝脏脂肪性变。     

In vitro genotoxicity of Melaleuca alternifolia essential oil in human lymphocytes

Ethnopharmacological relevance

The volatile essential oil derived from the plant Melaleuca alternifolia, also called tea tree oil (TTO), is largely employed for its antimicrobial properties against several human pathogens. It is used in many topical formulations to treat cutaneous infections.

Aim of the study

Since very few studies have been done on the safety and toxicity of the crude Melaleuca alternifolia essential oil, current investigation evaluates the possible genotoxic effects of TTO in human lymphocyte cultures.

Material and methods

The composition of current TTO sample was determined by GC/MS and NMR. The level of cytotoxicity in TTO treated cultures was determined by decrease of mitotic index when compared to that in negative control. The genotoxic potential of TTO was assessed by the in vitro mammalian cell micronucleus and the chromosome aberrations (CA) tests.

Results

Twenty-seven compounds were identified, accounting for 98.9% of the constituents. Terpinen-4-ol (42.8%), γ-terpinene (20.4%), p-cymene (9.6%), α-terpinene (7.9%), 1,8-cineole (3%), α-terpineol (2.8%) and α-pinene (2.4%) were the major compounds of the oil sample. None of the tested TTO concentrations (95 μg/ml, 182 μg/ml and 365 μg/ml) caused a significant increase in the observed frequencies of micronuclei when compared to those in the untreated cultures (negative control). Additionally, no significant differences regarding the frequencies of CA were observed among the tested TTO concentrations and the negative control.

Conclusions

Results demonstrate that TTO, in the tested concentrations, is not genotoxic in in vitro mammalian cells.     

黄连降糖片治疗糖尿病的药理作用研究

目的 研究黄连降糖片治疗糖尿病的药理作用。方法 用正常葡萄糖钳夹技术评价黄连降糖片对改善高脂+链脲佐菌素致大鼠胰岛素抵抗动物模型的胰岛素抵抗作用;用四氧嘧啶致大、小鼠糖尿病模型观察黄连降糖片的降血糖、降血脂作用和对白内障发生率的影响;用小鼠巨噬细胞吞噬鸡红细胞法和氧化钙法观察黄连降糖片对吞噬指数和耐缺氧的效果。结果 黄连降糖片对胰岛素抵抗动物模型的胰岛素抵抗有明显改善作用;对四氧嘧啶所致高血糖大、小鼠均有降血糖和降血脂作用,可明显降低糖尿病大鼠白内障发生率;明显延长小鼠的常压耐缺氧时间和提高小鼠腹腔巨噬细胞的吞噬指数。结论 黄连降糖片对糖尿病及其并发症有较好的治疗作用。     

乌龙茶及其有效成分对肝癌细胞HepG2的生长抑制作用

目的 通过探讨茶及其有效成分对肝癌细胞HepG2增殖的影响,为乌龙茶成分进一步开发提供有力的实验室证据.方法 体外培养人肝癌细胞株HepG2,加入浓度为25、50、100和200 mg/L的茶叶浸出液、茶多酚、茶色素、茶多糖、茶氨酸作用24h后,用水溶性四唑盐(WST-1)检测肝癌细胞的存活率.结果 乌龙茶及其有效成分对肝癌细胞HepG2进行干预后,各组肝癌细胞的增殖均被抑制,各组的吸光度值均低于阴性对照组,茶汤100 mg/L组和200 mg/L组、茶多酚各组和茶色素各组、茶多糖和茶氨酸50mg/L、100 mg/L和200 mg/L组,与阴性对照组比较,差异均有统计学意义(均P＜0.05).同时茶多酚25 mg/L组、茶色素25 mg/L组与茶汤25 mg/L组比较,差异均有统计学意义[(0.1658±0.0025)、(0.1913±0.0013)比(0.2005±0.0013),均P＜0.05];茶多酚50mg/L组、茶色素50mg/L组、茶多糖50 mg/L组、茶氨酸50 mg/L组与茶汤50 mg/L组比较,差异均有统计学意义[(0.1545±0.0041)、(0.1655±0.0039)、(0.1595±0.0019)、(0.1728 ±0.0040)比(0.1970 ±0.0078),均P＜0.05];茶多酚100 mg/L组(0.1370±0.0016)与茶汤100 mg/L组(0.1600 ±0.0037)比较,差异有统计学意义(P＜0.05).结论 乌龙茶及其有效成分对人肝癌细胞HepG2具有明显的抑制作用,表现出抗肝癌的作用.     

Antioxidant activity of different white teas: Comparison of hot and cold tea infusions

The study investigates the antioxidant characteristics of various white teas steeped in either hot or room-temperature water in relation to grade of tea and brewing conditions. Antioxidant activity, chelating activity, total phenol (TPC), flavonoids (TFC), theaflavins and individual catechin content were examined. The results confirm that extraction of tea leaves carried out with water at room temperature leads to the formation of infusions particularly rich in compounds with antioxidant activity. In fact, for all the white teas studied, cold infusions had a higher content of phenols (4.77–7.63 mmol/L Gallic Acid Equivalents, GAE), flavonoids (1.47–2.53 mmol/L Catechin Equivalents, CE) and catechins (441.5–1328.2 μg/mL) compared to hot infusions (1.43–4.02 mmol/L GAE, 0.70–1.13 mmol/L CE, 83.4–534.8 μg/mL, respectively). The same trend was also observed for antioxidant activities examined using the ABTS assay (cold: 17.09–34.23; hot: 5.26–17.07 mmol/L Trolox Equivalents) and by monitoring the effects of the infusions on LDL oxidation (lag time, cold: 172.4–271.2; hot: 88.4–145.9 min). A general trend in antioxidant activity and in polyphenolic compound content can be delineated between Chinese teas, i.e. Bai Mu Dan ≥ Xue Ya ≥ White Lung Ching > Anji Needle Mao Feng > Yhin Zhen Bai Hao and between African teas, i.e. White Salima Peony > Thyolo Bsp > Bvumbwe Bsp. Concerning metal chelating activity, all the white teas displayed similar levels (0.3–0.6 mmol/L EDTA Equivalents) with no significant differences between the hot and cold infusions (except Bvumbwe Bsp and Thyolo Bsp). This paper contains key information on the antioxidant properties, TPC, TFC, and individual catechin content of several white teas commercially available and the outcomes suggest that preparing tea infused in room temperature water for approximately 2 h may constitute an alternative tea beverage potentially richer in healthful bioactive compounds compared to the more commonly consumed hot tea infusions.     

茶多糖对链脲菌素诱导高血糖小鼠血糖血脂的影响

目的研究茶多糖对链脲菌素（STZ）诱导高血糖小鼠血糖血脂的影响,初步探讨茶多糖降血糖的作用机制。方法采用链尿菌素诱导高血糖小鼠模型,给药至第14d、28d测定其空腹血糖;给药至28d,测定血清胆固醇与甘油三酯,取肝脏,测定肝糖原含量。结果茶多糖能显著性降低给药第14d、28d空腹血糖及血清总胆固醇、甘油三酯含量,提高肝糖原含量。结论茶多糖对链脲菌素诱导的高血糖小鼠具有一定的降血糖降血脂的作用,其可能的作用机制是增加肝糖原含量有一定的关系。     

微波消解-电感耦合等离子体质谱(ICP - MS)法同时测定茶叶中25种元素

目的 建立同时测定茶叶中25种元素的微波消解 - 电感耦合等离子体质谱法,为茶叶质量监管提供技术支持。方法 以6种市售茶叶为样品,样品经微波消解后,利用ICP - MS同时测定茶叶中25种元素,以同位素内标法定量。结果 实验表明,K、Ca、Na、Mg、Fe的线性范围为 0～50 000 μg/L; Hg的线性范围为0～2 μg/L;其余元素的线性范围为0～1 000 μg/L;,相关系数均大于0.9 995;检出限为0.001mg/kg～0.800 mg/kg;回收率为96.7%～106.6%;相对标准偏差为0.66%～5.68%。结论 本方法快速、准确、灵敏,适用于批量茶叶中多元素的同时测定。     

基于网络药理学探讨加味桃核承气汤防治糖尿病肾病的作用机制

目的:运用计算机网络药理学技术预测加味桃核承气汤治疗糖尿病肾病的作用靶点和信号通路,进一步分析其防治糖尿病肾病的基础和作用机制。方法:运用中药系统药理学成分分析平台Bioinformatics Analysis Toolfor Molecular mech ANism of TCM(BATMAN-TCM)数据库获取加味桃核承气汤的有效成分及作用靶标基因,从Comparative Toxicogenomics Database(CTD)数据库收集糖尿病肾病的靶标基因,将两者取交集后得到疾病-药物蛋白靶基因,运用STRING构建蛋白质间相互作用网络,并通过Cytoscape软件将结果进行网络可视化展示,通过网络结构和节点间加权重联系的计算分析算法筛选出作用的关键基因。借助DAVID在线工具进行疾病-药物交集靶基因的基因本体论(GO)分析和京都基因与基因组百科全书(KEGG)通路富集分析,并采用Cytoscape软件BiNGO插件和ClueGO插件对靶点进行基因功能(GO)分析和基于KEGG通路富集分析的可视化展示。最后利用CTD数据库并结合文献学习,获取关键基因于糖尿病肾病的疾病治疗作用。结果:加味桃核承气汤的621个化合物中有581个靶点与糖尿病肾病相互关联。其中NOS3,OAT,NT5C2,ACACB,AGXT,PDE3B等关键基因主要通过调控神经组织的传递、胆碱能突触通路、钙离子通道、代谢通路、嘌呤代谢通路、血管紧张素-神经突触通路、环磷酸腺苷信号通路以及环磷酸鸟苷/环磷酸鸟苷酸依赖的蛋白激酶(cGMP/PKG)信号通路等路径,在质膜、突触后膜、线粒体等分子反应中发挥作用。结论:网络药理学方法科学预测加味桃核承气汤防治糖尿病肾病的关键靶标及其参与的相关通路,提示该方剂对糖尿病肾病的防治作用为多靶点、多通路、多选择的复杂机制,并且多与抗炎、氧化磷酸化及介导嘌呤代谢等机制相关。     

HPLC测定决明降脂茶中芦荟大黄素的含量

目的:建立测定决明降脂茶中芦荟大黄素含量的HPLC方法.方法:采用Dionex-C18柱(4.6 mm×250 mm,5μm),以乙腈∶0.1％磷酸(82∶18)为流动相,流速0.8 mL/min,柱温30℃,检测波长254 nm.结果:芦荟大黄素在2.42～48.4 μg/mL浓度范围内有良好的线性关系(r=0.9998),平均加样回收率为97.2％,RSD小于2.0％.结论:本方法简便、快速、准确、重复性好,可用于该制剂的质量控制.     

儿茶素类化合物的体外抗氧化作用研究

本实验通过DPPH·法、硫氰酸铁法等方法测定儿茶素清除DPPH·自由基、抗脂质过氧化和还原能力.研究结果表明儿茶素在清除自由基、抗脂质过氧化及还原能力方面均有一定作用,尤其是清除自由基和还原能力较对照品Vc强,差异性较显著;但在抗脂质过氧化方面儿茶素并未表现出剂量-效应关系,然而当加入表面活性剂后,增强了儿茶素的抗脂质过氧化活性.因此,儿茶素在清除自由基和还原能力方面均较优越,但在抗脂质过氧化方面较差,当加入适量的表面活性剂可以改善其活性.