蓑衣莲酮硫酸酯对对乙酰氨基酚诱导小鼠急性肝损伤的保护作用

蓑衣莲酮硫酸酯(Auriculatone sulphate,AS)是天然保肝活性化合物蓑衣莲酮的前药。为评估AS的保肝作用,课题采用小鼠腹腔注射300 mg/kg的对乙酰氨基酚(APAP)复制小鼠急性肝损伤模型,通过静脉注射给予25 mg/kg的AS,测定给药后小鼠血清中的谷草转氨酶(AST)、谷丙转氨酶(ALT)和乳酸脱氢酶(LDH)的含量变化,从肝损伤水平初步了解AS对肝脏的保护作用;通过测定肝组织中丙二醛(MDA)和谷胱甘肽(GSH)的水平以及超氧化物歧化酶(SOD)活性的变化,了解AS对氧化损伤的保护作用;通过小鼠肝组织的病理学检查,直观评价AS通过静脉注射给药后对肝脏的保护作用。研究结果显示,静脉注射AS能够显著降低血清中ALT、AST和LDH的水平,使其趋近于正常水平(P0.001)。与模型组相比,AS不但可以显著降低肝脏中MDA的水平(P0.001),而且显著增加GSH水平和SOD的活性(P0.001)。病理学检查显示,AS能显著改善APAP对肝组织的破坏,使肝组织的结构趋近于正常。综上,静脉注射AS可有效保护小鼠免受APAP诱导小鼠急性肝损伤,其保护作用可能与抑制肝脏氧化损伤有关。     

苦瓜甾醇对对乙酰氨基酚致小鼠肝损伤的保护作用

本文研究苦瓜甾醇对对乙酰氨基酚所致小鼠肝损伤的保护作用及其作用机制。48只小鼠随机分为6组(n=8):正常对照组、模型组、阳性对照组和苦瓜甾醇低、中、高剂量(50、100和200 mg/kg)组。各剂量组小鼠给予苦瓜甾醇连续灌胃7 d后,一次性腹腔注射对乙酰氨基酚400 mg/kg制备肝损伤模型,测定肝组织和血清的生化指标。与各苦瓜甾醇组比较,模型组小鼠血清中谷丙转氨酶(ALT)、谷草转氨酶(AST)水平显著升高,白蛋白(ALB)、总蛋白(TP)含量显著降低,肝组织中丙二醛(MDA)含量升高,超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-PX)活性下降。苦瓜甾醇有助于维持小鼠体内酶防御系统功能,提高清除自由基的能力,对对乙酰氨基酚所致小鼠肝损伤具有明显保护作用。     

银耳提取物对酒精性肝损伤辅助保护作用

探讨银耳提取物对小鼠肝损伤的保护作用。采用50%乙醇经口灌胃造成小鼠急性酒精性肝损伤模型,将动物随机分成5组,分别是空白对照组,模型组,银耳提取物低、中、高剂量组（3个剂量组分别为225、450、1 350mg/kg BW）,检测肝组织中丙二醛（MDA）、还原型谷胱甘肽（GSH）、甘油三酯（TG）的含量,并取肝脏作病理切片,观察肝脏的脂肪病变情况。结果显示银耳提取物3个剂量组肝组织MDA含量均低于模型组（P<0.01）;与模型组相比,各组GSH含量虽有所升高,但均无统计学差异（P>0.05）;中、高剂量组TG含量低于模型组（P<0.01）,且肝细胞脂肪变性均比模型组明显减轻（P<0.01）。结果提示银耳提取物对酒精性肝损伤有辅助保护功能。     

对乙酰氨基酚诱导的小鼠药物性肝损伤的模型研究

改良对乙酰氨基酚（acetaminophen,APAP）单独诱导小鼠急性肝损伤的模型和致死模型。随机将小鼠分为4组：空白对照组、APAP3h组、APAP6h组和APAP12h组,每组5只。饥饿15h后用对乙酰氨基酚诱发小鼠肝损伤。测定各组血清ALT、AST及胆红素含量,HE染色观察各组肝组织损伤情况。观察生存率时,小鼠随机分为对照组、禁食＋APAP（500mg／kg）组、禁食＋APAP（300mg／kg）组和不禁食＋APAP（500mg／kg）组,四组同时给药,然后记录各组小鼠的生存情况,绘制四组小鼠的生存曲线。小鼠注射APAP后,随时间的延长,ALT、AST水平逐渐升高,均明显高于空白对照组（P〈0．05）。小鼠肝脏HE染色可见,APAP中毒组小鼠肝细胞坏死及炎性细胞浸润。禁食＋APAP（500mg／kg）组小鼠自16h开始出现死亡,72h时全部死亡,死亡率明显高于不禁食组和禁食＋APAP（300mg/kg）组小鼠。该研究对APAPI起的C57／BL6小鼠药物性肝损伤模型进行改良,使其更加稳定和便于研究,为进一步探究APAP诱导肝毒性的机制及防治措施奠定了基础。     

熊果酸对糖尿病小鼠肝损伤的作用及其可能机制

目的：研究熊果酸对高脂饲料联合链脲佐菌素（STZ）诱导的糖尿病小鼠肝损伤的影响,探讨其可能的作用机制。方法：随机选取20只小鼠高脂饲料喂养6周后,STZ （30 mg/kg）腹腔注射连续5 d,9 d后测空腹血糖,大于11.1 mmol/L视为糖尿病模型,将其随机分为模型组和熊果酸组（100 mg/kg）（n=10）;另取10只小鼠设为对照组。连续给药8周。小鼠称重,测定空腹血糖（FBG）,血清总胆固醇（TC）、甘油三酯（TG）含量,谷丙转氨酶（ALT）、谷草转氨酶（AST）、超氧化物歧化酶（SOD）活性,丙二醛（MDA）含量,HE染色观察肝组织病理变化。结果：模型组与对照组比较,FBG、血清TC、TG含量,ALT、AST活性、MDA含量明显升高（P<0.05,P<0.01）;SOD活性明显降低（P<0.01）;HE染色显示部分肝细胞水肿,轻度脂肪变性,门管区可见淋巴细胞浸润。熊果酸组与模型组比较,FBG,血清TC、TG含量,ALT、AST活性、MDA含量明显降低（P<0.05,P<0.01）;SOD活性明显升高（P<0.01）;HE染色显示熊果酸组肝细胞排列较为整齐,水肿不明显,淋巴细胞少量存在。结论：熊果酸对高脂饲料联合STZ诱导的糖尿病小鼠肝损伤具有保护作用,其机制可能与降血糖、调节血脂、降低肝组织氧化应激水平,提高肝脏抗氧化能力有关。     

聚乙二醇修饰重组细胞珠蛋白对小鼠急性肝损伤的保护作用

旨在探究聚乙二醇修饰重组细胞珠蛋白(PEG modified recombinant cytoglobin,PEG-rCygb)对小鼠急性肝损伤的保护作用。采用CCl4诱导KM小鼠急性肝损伤模型,尾静脉注射PEG-rCygb,收集血清及肝脏组织检测各项生化指标及组织病理学变化。结果表明,PEG-rCygb治疗组小鼠肝脏系数减小,血清中AST﹑ALT水平降低,肝组织匀浆中MDA含量减少,GSH含量增加,T-SOD、CAT活性升高。肝组织切片HE染色显示PEG-rCygb可以缓解肝细胞脂肪变性,减少炎症因子,减轻肝细胞损伤。体外细胞学实验表明rCygb经PEG修饰后对H2O2造成的肝星状细胞(HSC)氧化损伤发挥的保护作用增强。研究结果显示PEG-rCygb提高了机体对自由基的清除能力,对CCl4引起的小鼠急性肝损伤具有保护作用。     

维生素K2对四氯化碳诱导的急性大鼠肝损伤的保护作用

探讨枯草芽胞杆菌产物维生素K2(MK-7)对四氯化碳诱导的急性肝损伤的保护作用及机制。

选取SPF级实验用6~8周龄SD雄性大鼠30只, 体质量200~220 g, 随机分为5组(每组6只): 空白组、肝损伤模型组、模型+溶剂组、模型+水飞蓟素组和模型+维生素K2组。空白组不做额外处理, 其余各组均予四氯化碳染毒, 溶剂组给予与维生素K2组相同体积的大豆油, 水飞蓟素组添加水飞蓟素100 mg/100 g体质量, 维生素K2组用维生素K2每日灌胃(给药剂量为2 μg/100 g体质量)。1周后观察大鼠体征和肝脏外观、肝脏炎症及微肉芽肿、肝细胞空泡化结构, 检测血液AST、ALT、MDA、SOD、TNF-α和IL-6含量。

与肝损伤模型组大鼠比, 模型+维生素K2组肝脏指数下降(t=3.250 0, P=0.031 4)。HE染色结果显示, 与肝损伤模型组大鼠比, 模型+维生素K2组空泡化程度明显降低, 损伤较为弥散。与肝损伤模型组大鼠比, 模型+维生素K2组肝功、氧化应激指标及相关炎症因子水平降低[AST(t=4.283 0, P=0.012 8)、ALT(t=2.582 0, P=0.041 6)、MDA(t=7.028 0, P=0.005 9)、SOD(t=3.384 0, P=0.011 7)、TNF-α(t=3.459 0, P=0.013 5)、IL-6(t=2.422 0, P=0.041 8)]。

维生素K2可减轻大鼠急性肝损伤程度, 其作用可通过改善抗氧化酶体系、抑制氧化应激反应及降低炎性因子水平而实现。

     

铁棍山药多糖对四氯化碳诱导的急性小鼠肝损伤的保护作用

为了研究铁棍山药(D.oppositacv.Tiegun)多糖对四氯化碳诱导的小鼠急性肝损伤的保护作用,取72只昆明小鼠随机分为对照组,四氯化碳(CCl4)模型组,阳性对照(联苯双酯)组,铁棍山药多糖低、中、高剂量组,每组12只,灌胃处理后使用CCl4制备急性肝损伤小鼠模型,观察各组形态学变化,同时测定生化指标。实验结果显示,经铁棍山药多糖处理的小鼠的肝损伤程度明显轻于模型组,铁棍山药多糖能降低小鼠血清中谷丙转氨酶(ALT)和谷草转氨酶(AST)含量,提高超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)的活性,降低丙二醛(MDA)、一氧化氮(NO)、肿瘤坏死因子-α(TNF-α)的含量。本研究结果表明,铁棍山药多糖对CCl4所诱导的小鼠肝损伤起到一定的保护作用。     

银杏叶提取物对过氧化氢诱导的星形胶质细胞氧化损伤的保护作用

目的 研究银杏叶提取物（EGb761）对H2O2所致星形胶质细胞氧化损伤的保护作用。方法 用不同浓度的EGb761预处理细胞,再加入H2O2,通过噻唑蓝（MTT）实验、线粒体跨膜电位（△ψm）及细胞色素C释放实验、DNA损伤实验及半胱氨酰天冬氨酸特异性蛋白酶-3（Caspase-3）活性测定,观察EGb761对细胞存活率、线粒体膜通透性、DNA氧化损伤及Caspase-3活性的影响。结果 EGb761能明显降低Hz02对星形胶质细胞的氧化损伤,提高细胞的存活率;维持线粒体膜的完整性,抑制跨膜电位的耗散和细胞色素C的释放;抑制Caspase-3的活化和DNA的降解。结论 EGb761具有清除活性氧,减轻H2O2所致星形胶质细胞的氧化损伤,对星形胶质细胞有保护作用。     

银杏叶提取物761对矽肺大鼠的防护作用

目的 探讨银杏叶提取物761(Ginkgo biloba Extract 761,EGb761)对矽肺大鼠的肺保护作用.方法 采用二氧化硅悬液气管内灌注法建立矽肺大鼠模型.二氧化硅灌注1 d后,每日灌服EGb761,持续4周.处死大鼠,收集肺组织.HE和Van Gieson(VG)染色法观察肺组织病理形态学情况,采用E...     

银杏叶黄酮提取方法比较

比较不同溶剂提取银杏（ＧｉｎｋｇｏｂｉｌｏｂａＬ．）叶黄酮类化合物的提取效率,从成本效益角度考虑,以７０％乙醇作为提取溶剂更为有利。在分级沉淀中,黄酮含量与蛋白质含量呈正相关,在乙醇提取液中黄酮和蛋白质含量最高;蛋白质的存在有助于提高黄酮的溶解度。乙醇提取液用饱和（ＮＨ４）２ＳＯ４浓缩两次,可使醇相中的黄酮沉淀析出。根据试验结果,提出了银杏叶黄酮的优化提取方法。     

Ginkgo biloba extract for essential hypertension: A systemic review

BackgroundGinkgo biloba extract (GBE), a traditional natural herbal product, is often used in the treatment of essential hypertension (EH) as complementary therapy in China and European countries.AimTo critically assess the current clinical evidence of efficacy and safety of GBE for EH.Methods7 electronic databases (Cochrane Library, PubMed, EMBASE, VIP, CBM, Wanfang data, and CNKI) were searched to identify randomized controlled trials (RCTs) of GBE for EH. Methodological quality was assessed independently using the Cochrane Handbook for Systematic Reviews of Interventions.ResultsA total of 9 RCTs with 1012 hypertensive patients were identified and reviewed. Most RCTs were of high risk of bias with flawed study design and poor methodological quality. 6 trials demonstrated potential positive effect of GBE as complementary therapy on BP reduction when compared with antihypertensive drug therapy; however, it was not associated with a statistically significant effect on both SBP and DBP reduction in 3 other trials. Despite the positive findings, there were so many methodological limitations and significant clinical heterogeneity. Most of the trials did not report adverse effects, and the safety of GBE is still uncertain.ConclusionNo confirmative conclusions on the efficacy and safety of GBE for EH could be drawn. More rigorous trials are warranted to support their clinical use.     

Protective effect of wild Corni fructus methanolic extract against acute alcoholic liver injury in mice

Background: In Chinese folk medicine, Corni fructus (C. fructus) has traditionally been used to improve liver function, although the mechanism underlying its activity remains unclear. The aim of the present study was to evaluate the protective effects of wild C. fructus methanolic extract against acute alcoholic liver injury.

Methods: Alcohol was administered to mice for three consecutive days, either alone or in combination with C. fructus methanolic extract (50, 100, or 200?mg/kg body weight/d). Serum and liver tissue were collected from the animals and subjected to biochemical and histopathological analyses.

Results: C. fructus signi?cantly alleviated alcohol-induced liver injury by reducing serum alanine aminotransferase, aspartate aminotransferase, and thiobarbituric acid reactive species, inhibiting hydroxyl radicals (?OH), and increasing total superoxide dismutase, glutathione peroxidase, and glutathione in the liver (P?C. fructus treatment inhibited the expression and activity of cytochrome P450 2E1 (P?Conclusions: C. fructus could be a promising natural substance for ameliorating acute alcohol-induced oxidative stress and hepatic injury.     

Ginkgo biloba extract modifies hypoglycemic action of tolbutamide via hepatic cytochrome P450 mediated mechanism in aged rats

We examined hepatic cytochrome P450 (CYP)-mediated interactions between Ginkgo biloba extract (GBE) and tolbutamide, an oral anti-diabetic agent, in aged and young rats. Tolbutamide was orally given to rats with or without GBE treatment, and time-dependent changes in blood glucose were monitored. The basal activity of six CYP subtypes in liver was lower in the aged rats than in the young rats, while the inductions of these enzymes by 5 day pretreatment of 0.1% GBE diet were more in the aged rats. Further, the pretreatment of GBE significantly attenuated the hypoglycemic action of tolbutamide in the aged rats, corresponding well to the enhanced activity of (S)-warfarin 7-hydroxylase, which is responsible for CYP2C9 subtype, a major isoform metabolizing tolbutamide. In contrast, the simultaneous administration of GBE with tolbutamide potentiated the hypoglycemic action of this drug. The in vitro experiments revealed that GBE competitively inhibited the metabolism of tolbutamide by (S)-warfarin 7-hydroxylase in the rat liver microsomes. In the young rats, the 5 day pretreatment with GBE significantly attenuated the hypoglycemic action of tolbutamide, but a simultaneous treatment had little influence on the tolbutamide effect. In conclusion, the present study has shown that the simultaneous and continuous intake of GBE significantly affects the hypoglycemic action of tolbutamide, possibly via a hepatic CYP enzyme-mediated mechanism, particularly in the aged rats. Therefore, it is anticipated that the intake of GBE as a dietary supplement with therapeutic drugs should be cautious, particularly in elderly people.     

Antiestrogenic activities of Ginkgo biloba extracts

Most climacteric and postmenopausal women appear to have vasomotor symptoms as well as a high risk of osteoporosis and cardiovascular disease. Although exogenous estrogens can reduce these symptoms, women are reluctant to use hormone replacement therapy (HRT) due to its undesirable side effects, such as irregular bleeding and an increased risk of breast cancer. A previous study suggested that Ginkgo biloba extracts (GBE) have estrogenic activity and might be suitable as an alternative to HRT. However, there are no reports of the preventive effect of GBE on breast cancer, which is the side effect of classical HRT. In this study, it was confirmed that GBE exhibits estrogenic and antiestrogenic activity depending on the E₂ and GBE concentration, via estrogen receptor (ER)-dependent and ER-independent pathways. In addition, GBE reduced the E₂ levels by stimulating the E₂ metabolism and inhibiting E₂ synthesis, which indicates that GBE can induce antiestrogenic activity via the depletion of E₂. Furthermore, GBE might have similar action to selective arylhydrocarbon receptor modulators (SAhRMs), which induce antiestrogenic activity through cross-talk between the arylhydrocarbon receptor (AhR) and ER. In conclusion, GBE has a biphasic effect on estrogen, and can be considered as a potential alternative to HRT with chemopreventive effects on breast cancer. However, further studies on animals and humans will be required.     

三七总皂甙和银杏叶提取物预防急性氧中毒的实验研究

目的:研究三七总皂甙和银杏叶提取物对急性氧中毒的预防作用及其可能机制.方法:分别给小鼠连续腹腔注射三七总皂甙和银杏叶提取物5 d后,在500kPa高压氧中暴露60 min,观察惊厥潜伏期、惊厥次数、惊厥间隔时间等指标;另外测定高压氧暴露15 min后脑组织中活性氧单位、脂质过氧化物、一氧化氮、谷胱甘肽的含量和过氧化氢酶、谷胱甘肽过氧化物酶、单胺氧化酶的活性.结果:三七总皂甙和银杏叶提取物可以明显延长氧惊厥潜伏期和惊厥间隔时间,减少惊厥次数;降低高压氧暴露后脑组织中脂质过氧化物、一氧化氮的含量,使活性氧单位、谷胱甘肽含量和谷胱甘肽过氧化物酶活性保持在较高的水平;对过氧化氢酶和单胺氧化酶活性的影响则不显著.结论:三七总皂甙和银杏叶提取物可以有效预防急性氧中毒,其机制可能与它们的抗氧化活性有关.     

银杏叶提取物分子聚集形态

研究银杏叶提取物水溶液中多组分分子间的相互作用;采用动态光散射法和透射电镜扫描法,探讨银杏叶提取物水溶液是否存在分子聚集形态、分子聚集体粒径大小以及体外模拟不同胃肠pH环境条件下,银杏叶提取物水溶液分子聚集体的稳定性.实验数据证实银杏叶提取物水溶液存在纳米级分子聚集体,分子聚集体粒径在60 nm至100 nm之间;水溶液中1 nm以下的粒子大都是一些成分以单分子形式存在;随着溶液的浓度增加,分子聚集体的粒径也增大;在不同pH条件胃肠环境下,银杏叶提取物水溶液分子聚集体可以稳定存在.     

银杏叶超临界流体提取物对杉木种子的发芽效应

采用正交试验设计L8(2^7)及超临界萃取技术,乙醇作夹带剂,就银杏(Ginkgo biloba L.)叶提取物对杉木[Cunninghamia lanceolata (Lamb.) Hook.]种子的发芽效应进行了生物检测。结果表明：不同萃取条件下,纯CO2及夹带剂和CO2混合萃取的银杏叶提取物对杉木种子发芽的影响不同;就尉值(敏感指数)而言,在纯CO2萃取的浓度为200mg／kg银杏叶提取物中,杉木种子绝对发芽率为0．23,绝对发芽势为0．15,胚根长为0．01,胚轴长为-0．02;夹带剂和CO2混合萃取的浓度为200mg／kg银杏叶提取物除了对杉木种子绝对发芽率和绝对发芽势表现为促进作用外(尉值分别为0．03和0．34),对胚根长及胚轴长则表现为轻微的抑制作用(尉值分别为-0．09和-0．03)。     

Effects of Ginkgo biloba extract (EGb 761) on learning and possible actions on aging

A study of the effect of Ginkgo biloba extract (EGb 761) has shown enhancing effects on training in adult and aged Swiss mice. An analysis of inbred mice has confirmed this sensitivity to EGb 761, but depending on the strains, with different effects at different ages. The most interesting results are related to improvements in performances observed with aged mice of the DBA/2J strain. The results obtained with inbred strains in the study of the mossy fibers of the hippocampus make it possible to suggest a link between the improvements in training and the histological structure of the hippocampus. This possibility, which can be confirmed by further studies, is presented here.     

银杏外种皮提取物对几种蔬菜病原菌的抑制作用

以银杏外种皮提取物对几种蔬菜病原菌进行抑菌效果检测,结果表明,乙醇提取物、甲醇提取物的抑菌效果较好。乙醇提取物浓度为500 mg·mL^-1时,抑菌效果除对甘蓝黑斑病菌为88.5%外,对白菜炭疽病菌、茄子立枯病菌、茄子白绢病菌、黄瓜枯萎病菌均为100%。甲醇提取物浓度为500 mg·mL^-1时,对上述5种病菌的抑菌率均为100%。这为今后田间防治5种病菌及开发银杏植物源杀菌剂提供科学依据。