蒺藜皂苷对大鼠动脉粥样硬化形成的影响

观察从全草中所提蒺藜总皂苷(tribu saponin from Tribulus terrestris,STT)对大鼠动脉粥样硬化(atherosclerosis,AS)形成的影响,从而探讨其对AS的治疗作用.应用高脂饲料饮食配合注射维生素D3建立SD大鼠AS模型,并设立正常组、模型组、辛伐他汀组和蒺藜皂苷低、中、高三个剂量组.实验8周后处死大鼠,测量各组大鼠体重、肝脏重量;检测血清丙二醛(MDA)、总抗氧化能力(T-AOC)及血脂生化指标和肝脏总胆固醇(TC)、甘油三酯(TG)水平;苏木素伊红(HE)染色观察主动脉组织、肝组织形态学变化.结果显示,与模型组相比,蒺藜皂苷三个剂量组能够降低大鼠肝脏TC水平(P<0.01～P<0.05),而低、中剂量的蒺藜皂苷可以显著降低肝脏TG水平(P<0.01～P<0.05);低、高剂量的蒺藜皂苷能够提高血清高密度脂蛋白胆固醇(HDL-C,P<0.01);三个蒺藜皂苷剂量均能降低血清 MDA水平(P< 0.01),并且高剂量的蒺藜皂苷能够降低血清T-AOC(P<0.05);同时观察到蒺藜皂苷不同程度的改善了主动脉及肝组织病理损伤.提示蒺藜皂苷具有一定的抗动脉硬化形成的作用.     

三七总皂苷联合顺铂对胃癌大鼠肾损伤的改善作用及机制分析

摘要 目的：探讨三七总皂苷联合顺铂对胃癌大鼠肾损伤的改善作用并分析潜在机制。方法：选择60只健康SD雄性大鼠分为对照组、胃癌模型组、顺铂组及三七总皂苷组,各15只。除对照组外,其余组大鼠采用皮下接种胃癌BGC823细胞悬液法建立胃癌模型。建模成功后,给予对照组和胃癌模型组大鼠生理盐水腹腔注射和灌胃,给予顺铂组大鼠腹腔注射25 mg/kg顺铂注射液并灌胃生理盐水,给予三七总皂苷组大鼠腹腔注射25 mg/kg顺铂注射液并灌胃30 mg/kg三七总皂苷。分别于建模成功时、药物处理28 d时采用酶联免疫吸附法检测血清肌酐（SCr）、尿素氮（BUN）和尿液β-N-乙酰氨基葡萄糖苷酶（NAG）、肾损伤分子1（KIM-1）水平。处死大鼠后取肾脏,分别测定肾脏组织匀浆中超氧化物歧化酶（SOD）、丙二醛（MDA）、过氧化氢酶（CAT）、谷胱甘肽（GSH）水平,制备肾脏组织石蜡切片并行苏木精-伊红染色后观察大鼠肾组织的病理学变化。采用TUNEL染色法检测肾脏组织细胞凋亡情况,采用Western Blotting法检测肾脏组织中LC3、HIF-1α和Beclin1 蛋白表达情况。结果：顺铂组和三七总皂苷组大鼠血清SCr、BUN和尿液NAG、KIM-1水平均显著高于对照组和模型组（P<0.05）,三七总皂苷组大鼠血清SCr、BUN和尿液NAG、KIM-1水平显著高于顺铂组（P<0.05）。三七总皂苷组大鼠肾脏组织SOD、GSH水平显著低于模型组但显著高于顺铂组,MDA显著高于模型组但显著低于顺铂组（P＜0.05）,CAT与模型组无显著差异（P＜0.05）,但显著高于顺铂组（P>0.05）。顺铂组大鼠肾小管明显扩张、管腔狭窄,基底层上皮细胞水肿、坏死并形成空泡,肾小管。三七总皂苷组大鼠肾脏病理学改变程度显著轻于顺铂组。顺铂组和三七总皂苷组大鼠肾脏组织细胞凋亡指数显著增加,三七总皂苷组大鼠肾脏组织细胞凋亡指数显著低于顺铂组（P＜0.05）。顺铂组大鼠肾脏组织中LC3、HIF-1α和Beclin1蛋白水平均显著高于模型组,但显著低于三七总皂苷组（P＜0.05）。结论：三七总皂苷可能通过减轻过氧自由基和过氧化水平、增强线粒体自噬水平减少肾组织细胞凋亡,减轻顺铂引起的胃癌大鼠肾损伤。     

蒺藜总皂苷对阿尔茨海默病模型大鼠记忆能力的影响

本实验观察蒺藜总皂苷（GSTT）对三氯化铝（A1C13）诱导的AD模型大鼠学习记忆能力的影响,为GSTT防治AD提供实验依摧。SD雄性大鼠60只,随机分为对照组、AD模型组、脑复康组、GSTT大剂量组、GSTT中剂量组和GSTT小剂量组,每组10只。AD模型组、脑复康组、GSTT各剂量组每日上午给予A1C13灌胃,每日1次,连续9周。脑复康组、     

皂苷类药物代谢实验方法研究进展

许多皂苷类天然产物具有医疗保健作用。本文主要从皂苷药代体内外研究方法、皂苷药代生物样品预处理方法和检测方法等方面,概述了皂苷成分药物代谢实验方法的研究进展情况。     

竹节参培养细胞提取的竹节参总皂苷对大鼠佐剂性关节炎的抑制作用

为了探讨竹节参培养细胞所提取的竹节参总皂苷对大鼠佐剂性炎症的治疗效果,利用雄性AA大鼠构建病理模型,通过致炎前和致炎后口服给药,研究了竹节参总皂苷对于大鼠原发性以及继发性佐剂性关节炎的预防和治疗效果。实验结果表明,从竹节参培养细胞中分离到的竹节参总皂苷能够预防和显著减轻AA大鼠佐剂性关节炎的原发性病变;竹节参总皂苷也能够很好地减轻和治疗AA大鼠佐剂性关节炎的继发性病变。竹节参总皂苷的有效剂量为35～140 mg/kg。实验证明,从竹节参培养细胞中提取的竹节参总皂苷与天然竹节参提取物一样均具有良好的抗炎作用。     

皂苷类药物的制剂研究进展

皂苷类药物普遍分子量比较大,水溶性好,但不易透过细胞膜难以被人体吸收,因此口服制剂体内生物利用度较低.近年来对单体皂苷及总皂苷类药物制剂方面的研究越来越多,随着新型的给药系统和新辅料的出现,皂苷类药物在体内的生物利用度大大提高.本文主要介绍以单体皂苷或总皂苷活性部位为主药的制剂研究进展,以期为该类成分的进一步研究提供思路.     

高效转化黄姜皂苷为薯蓣皂苷元菌株的筛选及转化条件优化

薯蓣皂苷元是甾体激素类药物重要的生产原料,在制药工业中有广泛应用。传统的生产方法是黄姜酸解法,污染严重。为寻找更清洁高效的生产方式,从本实验室保藏的菌株中筛选出一株赤霉菌Gibberellaintermedia WX12(层出镰孢菌Fusarium proliferatum的有性阶段),能将黄姜中的皂苷转化为薯蓣皂苷元。采用统计学实验设计方法对其转化培养基进行研究,优化的转化培养基配方为(g/L):葡萄糖20.6;酵母膏5.0;氯化钠1;磷酸二氢钾3;硫酸锌1.5;黄姜酶解物3。采用以上优化参数,薯蓣皂苷元的得率提高到(31±0.3)mg/g干黄姜,较优化前提高了3倍。这是目前关于赤霉菌转化黄姜中皂苷的首次报道。     

一种真菌对人参皂苷Rg3的转化

[目的]筛选长白山人参土壤中的活性微生物,转化人参总皂苷及单体人参皂苷产生稀有抗肿瘤成份.[方法]从长白山人参根际土壤中分离各类菌株,对人参总皂苷及单体人参皂苷进行微生物转化,并通过硅胶柱层析等方法对转化产物进行分离纯化,采用波谱解析及理化常数对其进行结构鉴定;结合菌落形态、产孢结构、孢子形态特征以及菌株ITS rDNA核酸序列分析,对活性菌株进行鉴定.[结果]从长白山人参根际土壤中分离各类真菌菌株68株,有12株菌株对人参总皂苷有转化活性,其中菌株SYP2353对二醇组人参皂苷Rg3具有较强的转化活性.[结论]阳性菌株SYP2353被鉴定为疣孢漆斑菌(Myrothecium verrucaria),能将人参皂苷Rg3转化为稀有人参皂苷Rh2及二醇组人参皂苷苷元PPD,为稀有人参皂苷Rh2的制备提供了新的方法.     

水溶性三七总皂苷制备与表征

为提高三七总皂苷的水溶性及其制剂在体内的稳定性和生物利用度,运用喷雾干燥法对三七总皂苷进行超细化,利用正交试验分析得到喷雾干燥制备三七总皂苷超细粉的最佳条件并对其各项指标进行检测。经分析所得最佳制备条件为：进口温度为140℃、三七总皂苷的浓度为65 g·L^-1、进料流速为30 L·h^-1和空气脉冲为4。对三七总皂苷原粉和喷雾干燥所得超细粉进行了理化性质检测,SEM扫描结果显示超细粉形貌规则,激光粒度仪测得粒径为70.5 nm;红外光谱检测所得结果证实超细粉化学性质较原粉无明显改变,不影响其药性;通过DSC、X-Ray检测所得结果显示超细粉与原粉相比晶体结晶度有所改变说明其水溶性增加。     

中国薯蓣属植物中的甾体皂苷及甾体皂苷元

中国薯蓣属(Dioscorea L.)植物含有约21种甾体皂苷元,其中大部分种类含有3β-羟基皂苷元,少数种类含有3α-羟基皂苷元。从薯蓣属13种植物中共分离出59个甾体皂苷成分,按化学结构可将这些甾体皂苷分为4种类型。约有17种薯蓣属植物含有甾体皂苷元(主要为薯蓣皂苷元),均为根茎组(Sect.Stenophora)种类。在查阅大量资料的基础上,对各种类所含的甾体皂苷元和甾体皂苷成分及各成分的化学结构进行了归纳和综述。     

蒺藜皂苷对糖基化终产物形成及其诱导的内皮细胞功能障碍影响研究

本文探讨蒺藜皂苷(STT)对糖基化终产物(AGEs)形成及AGEs诱导的内皮细胞功能障碍的影响。以荧光法检测AGEs体外形成,MTT法检测细胞存活率,试剂盒方法检测细胞及培养上清液中的一氧化氮(NO)水平、诱导型NO合酶(iNOS)活力和超氧阴离子水平(O2-.)。结果显示STT促进AGEs形成,并加剧AGEs诱导的内皮细胞生长抑制,提高细胞NO分泌,增加iNOS活力和O2-.水平。与海可、替告皂苷元作用进行比较,发现STT的细胞损伤作用可能是海可皂苷元引起的。提示STT未能抑制体外AGEs形成,对AGEs引起的内皮细胞功能障碍无明显保护作用,反而可能通过增强iNOS酶活加剧细胞损伤。     

The response of muscle protein synthesis to nutrient intake in postabsorptive rats: The role of insulin and amino acids

In 12 h fasted rats, rates of muscle protein synthesis were stimulated by refeeding for 1 h and by intragastric or intravenous infusion of an amino acid plus glucose mixture for 1 hr, but not by intravenous infusion of amino acids alone for 1 h. Intravenous injection of anti-insulin serum suppressed the response to feeding and to intragastric infusion, but not to intravenous infusion. It is concluded that the response of muscle protein synthesis to food intake is mediated by both insulin and amino acids acting in concert.     

Early osmoregulatory stimulation of neurohypophyseal hormone secretion and thirst after gastric NaCl loads

Cerebral osmoreceptors mediate thirst and neurohypophyseal secretion stimulated by increases in the effective osmolality of plasma (P(osmol)). The present experiments determined whether an intragastric load of hypertonic saline (ig HS; 0.5 M NaCl, 4 ml) would potentiate these responses before induced increases in P(osmol) in the general circulation could be detected by cerebral osmoreceptors. Adult rats deprived of water overnight and then given intragastric HS consumed much more water in 15-30 min than rats given either pretreatment alone, even though systemic P(osmol) had not yet increased significantly because of the gastric load. In other rats pretreated with an intravenous infusion of 1 M NaCl (2 ml/h for 2 h), plasma levels of vasopressin and oxytocin were considerably elevated 15 and 25 min after intragastric HS treatment, whereas systemic P(osmol) was not increased further. These and other findings are consistent with previous reports that hepatic portal osmoreceptors (or Na(+) receptors) stimulate thirst and neurohypophyseal hormone secretion in euhydrated rats given gastric NaCl loads and indicate that these effects are potentiated when animals are dehydrated.     

Abdominal vagal mediation of the satiety effects of CCK in rats

CCK type 1 (CCK1) receptor antagonists differing in blood-brain barrier permeability were used to test the hypothesis that satiety is mediated in part by CCK action at CCK1 receptors on vagal sensory nerves innervating the small intestine. Devazepide penetrates the blood-brain barrier; A-70104, the dicyclohexylammonium salt of N alpha-3-quinolinoyl-D-Glu-N,N-dipentylamide, does not. At dark onset, non-food-deprived control rats and rats with subdiaphragmatic vagotomies received a bolus injection of devazepide (2.5 micromol/kg i.v.) or a 3-h infusion of A-70104 (3 micromol.kg(-1).h(-1) i.v.) either alone or coadministered with a 2-h intragastric infusion of peptone (0.75 or 1 g/h). Food intake was determined from continuous computer recordings of changes in food bowl weight. In control rats both antagonists stimulated food intake and attenuated the anorexic response to intragastric infusion of peptone. In contrast, only devazepide was effective in stimulating food intake in vagotomized rats. Thus endogenous CCK appears to act both at CCK1 receptors beyond the blood-brain barrier and by a CCK1 receptor-mediated mechanism involving abdominal vagal nerves to inhibit food intake.     

Saponins in Tribulus terrestris – Chemistry and Bioactivity

Tribulus terrestris is a valuable herb known for its application in the folk medicine in many parts of the world. Furostanol and spirostanol saponins of tigogenin, neotigogenin, gitogenin, neogitogenin, hecogenin, neohecogenin, diosgenin, chlorogenin, ruscogenin and sarsasapogenin type are frequently found in this plant. Four sulphated saponins of tigogenin and diosgenin type are also isolated. Extracts and steroidal saponins have been found to possess various pharmacological activities. Preparations based on the saponin fraction of T. terrestris are used for treatment of infertility and libido disorders in men and women, as well as for treatment of cardiac diseases. Food supplements containing T. terrestris extracts are on sale in USA and Europe with claim of a general stimulating action. In this review the steroidal saponins found in T. terrestris are presented, covering the literature up to 2004. The data reveal clear difference in the saponin composition of samples from this plant species collected from different geographical regions. A comprehensive account on the biological activity of extracts and individual saponins is also included.     

Alteration by Diacylglycerols of the Transport and Fatty Acid Composition of Lymph Chylomicrons in Rats

Lymph fistula rats were continuously infused with emulsions containing diacylglycerol consisting of 1,3-species (65.6%), 1(or 3),2-species (32.6%), and triacylglycerol (rapeseed oil) at the rate of 3ml/h for 1 h through a cannula inserted into the stomach. The lymph fluids were collected every hour for 5 h after starting the infusion of the lipid emulsions, and the lymph chylomicrons were isolated, purified and analyzed. Test emulsions were prepared to provide the same amount of fatty acids (144mg/h) as that in these acylglycerols. The rates for triacylglycerol transport at 2–3 h and for cholesterol transport by chylomicrons at 2–3 h and 3–4 h of the experimental period in rats infused with the diacylglycerol emulsion were significantly lower than the corresponding values in the rats infused with the triacylglycerol emulsion. As a consequence, the cumulative value for triacylglycerol transport at the end of the experimental period in rats infused with the diacylglycerol emulsion was significantly lower than the corresponding value in the rats infused with the triacylglycerol emulsion. In addition, cumulative values for cholesterol transport from 3h to the end of the experimental period were significantly lower in the former than in the latter. There was no difference in the total fatty acid compositon of chylomicron-triacylglycerol between the rats receiving the triacylglycerol and diacylglycerol emulsions. However, a considerable difference existed in the fatty acid composition at the 2-position of triacylglycerol between the two groups of rats. Thus, intragastric infusion of diacylglycerol mainly consisting of the 1,3-species compared to triacylglycerol not only altered the rate of lipid transport by lymph chylomicrons but also altered the structure of the triacylglycerol moiety in the rats.     

Intragastric pH and Pharmacokinetics of Intravenous Ranitidine During Sinusoidal and Constant-Rate Infusions

Six patients with healed duodenal ulcer completed two treatment periods with continuous i.v. infusion ranitidine. A 25-mg i.v. bolus was followed by a constant infusion at 6.25 mg/h or a sinusoidal infusion with infusion rates ranging from 3.125 to 9.375 mg/h. The sinusoidal infusion rate was designed to match the previously observed circadian changes in basal acid secretion. The peak infusion rate occurred at 19:30 h. A pharmacokinetic method was designed to predict the resultant plasma concentrations of ranitidine. Intragastric pH and plasma ranitidine concentration data were fit to a cosine function to evaluate circadian and ultradian rhythms. Plasma concentrations during the sinusoidal infusion exhibited a circadian rhythm according to model predictions. Cosinor analyses of the mean ranitidine plasma concentration data showed a mesor concentration of 237 ng/mL and amplitude of 76 ng/mL (coefficient of determination [CD] = 0.98). The acrophase in plasma concentration occurred at 2223 h, a delay of approximately 2.9 hours from the peak in the infusion rate. The constant-rate infusion resulted in a mean plasma concentration of 222 ± 32 ng/mL. The 24-h mean intragastric pH values for the sinusoidal and constant regimens were 5.4 and 5.1, respectively (p = 0.170). The intragastric pH during the constant-rate infusion exhibited a significant circadian rhythm (CD = 0.52). The minimum pH (bathy-phase) occurred at 2031 h. No circadian rhythm was present during the sinusoidal-rate infusion (CD = 0.08). At the approximate time of the peak basal acid secretion, between 21:00 hours and midnight, the mean pH for the sinusoidal infusion was 5.77 versus 4.5 for the constant-rate infusion (p = 0.112). Sinusoidal infusions or alternate methods of increased doses at the times of peak acid output may improve around-the-clock control of intragastric pH.     

Production of sapogenins (stigmasterol and hecogenin) from genetically transformed hairy root cultures of <Emphasis Type="Italic">Chlorophytum borivilianum</Emphasis> (Safed musli)

Chlorophytum borivilianum belonging to the family Liliaceae, is distributed in the pantropical regions of India and South Africa. The sapogenins (stigmasterol and hecogenin) of C. borivilianum are well known for their appetizing and aphrodisiac properties. The present study involves enhancing the sapogenin content in C. borivilianum by genetic transformations with Agrobacterium rhizogenes strains (MTCC 2364 and 532, PRT Gus). A maximum transformation frequency of 98% was obtained with Agrobacterium rhizogenes MTCC 2364 strain with rhizome explants after a co-cultivation period of 48 h. Two potential rhizoclones (2364a and 2364b) were selected for the production of stigmasterol and hecogenin. The maximum production of stigmasterol (83.952?±?0.01 mg/g) was seen in 2364b rhizoclone, whereas, the highest accumulation of hecogenin (81.52?±?0.02 mg/g) was observed in 2364a rhizoclone. The C. borivilianum hairy root cultures obtained in this study provide a continuous and sustainable production of stigmasterol and hecogenin on a commercial scale.     

Meal-stimulated exocrine pancreatic secretion and release of GI peptides in normal and nicotine-treated rats

In rats, treated chronically with saline and nicotine, we studied the postprandial release of gastrin and cholecystokinin by specific radioimmunoassays and simultaneously measured secretory outputs of the exocrine pancreas. Rats were prepared surgically with gastric and pancreatic fistulas. Meal-stimulated release of peptides and exocrine secretory outputs were measured 24 h postoperatively in conscious rats. Infusion of food via intragastric cannula significantly stimulated plasma gastrin levels in both control and nicotine treated rats. Postprandial gastrin levels in nicotine treated rats were significantly higher compared to gastrin levels obtained after food in untreated control rats. Plasma CCK levels were increased in both groups after food. These levels remained significantly elevated from the basal values only for a transient period following infusion of the liquid meal. There were no differences in postprandial plasma CCK levels between the two groups. Outputs of exocrine pancreatic volume, protein and trypsin increased significantly after food in both control and nicotine treated groups of rats. The differences in outputs of volume and protein between the two groups of rats were not significant; however, the trypsin outputs in the nicotine rats were decreased significantly when compared to control rats. The data indicate that in rats, administration of food stimulated the release of immunoreactive gastrin and CCK with concomitant increase in exocrine pancreatic secretions of volume, protein and trypsin. Chronic nicotine treatment and its effect on food, however, appeared to have induced hyperfunction of G-cells that resulted in increased gastrin secretion and a decrease in trypsin secretion by exocrine pancreas. These data may have important implications in the etiology of the development of exocrine pancreatic dysfunction in chronic smokers.     

Escape from tolerance of organic nitrate by induction of cytochrome P450.

The mechanism of organic nitrate tolerance is poorly defined. We studied the rat P450-catalyzed conversion of organic nitrate to nitric oxide (NO) by purified P450 isoforms relationship between P450 expression and nitrate tolerance following continuous infusion of organic nitrates in rats. The hypotensive effect of an nitroglycerin (NTG) bolus injection was abolished in rats that had been previously provided a continuous 48 h infusion of NTG. This effect was accompanied by a gradual but marked decrease in plasma and urinary nitrate levels following a peak at 18-24 h. Nitrate tolerance was reversible; the decline in the hypotensive effect and P450 levels observed after 2 d of continuous infusion was followed by restoration to control levels 2 d after cessation of the infusion. Similarly, the hypotensive action disappeared in P450-depleted, and -inhibited rats. At 48 h after infusion, NTG-induced NO generation of the vessels increased in acetone (a P450 inducer) -pretreated rats. The appearance and disappearance of P450 paralleled the conversion of organic nitrates to NO. Our observations indicate that nitrate tolerance is in large part the result of decreased P450 expression and activity. Interventions that maintain or increase P450 activity may be a strategy to provide relief from ischemic conditions in humans.