单宁酸处理带瓣牛颈静脉的生物学评价

目的从生物学角度评价单宁酸处理的带瓣牛颈静脉是否符合国家医用材料的要求。方法带瓣牛颈静脉经单宁酸处理后按国家医用材料的要求进行浸提液的制备、细胞毒性试验、过敏试验、皮内刺激试验、原发性皮肤刺激试验、溶血试验、急性全身毒性试验及热原试验等生物学评价试验。试验方法均参照《医用有机硅材料生物学评价试验方法》GB／T16175-1996。结果培养的L-929小鼠成纤维细胞经含浸提液的培养基培养后形态良好，增值旺盛，材料细胞毒性评级为0～1。无皮肤刺激反应和过敏反应，皮内刺激试验PⅡ（原发性刺激指数）为0．4，和阴性对照组差异无统计学意义。全身毒性实验受试动物未出现毒性症状。溶血试验溶血率0．7％，符合国家标准（〈5％）。热原试验经中国药品生物制品检定所检定，单宁酸处理后带瓣牛颈静脉无热原（样品批号：060802017）。结论单宁酸处理的带瓣牛颈静脉符合国家医用材料的要求，可以植入人体。     

荨麻鞣质的体内抗氧化活性研究

为了说明荨麻鞣质的体内抗氧化活性,给小鼠灌胃荨麻鞣质50mg/kg·d,100mg/kg·d及200mg/kg·d共7d,7天后测定小鼠体内超氧化歧化酶（SOD）、过氧化氢酶（CAT）、谷胱甘肽（GSH）和丙二醛（MDA）含量,说明荨麻鞣质能够明显提高小鼠抗氧化系统功能,初步确定荨麻鞣质的抗氧化性。     

正交设计优选超声波提取刺玫果中总鞣质的工艺研究

目的:本实验旨在考察超声波提取剌玫果总鞣质的最佳工艺条件。方法:本试验采用超声波法提取刺玫果总鞣质,用正交设计L_9(3~4)表优选超声提取的条件,采用干酪素法测定总鞣质含量。结果:超声波提取的最佳工艺为刺玫果粉末过100目筛、8倍溶剂量、提取功率400瓦、提取时间1h。测得刺玫果中总鞣质平均含量为2．467％。结论:超声波提取刺玫果中总鞣质是可行的。     

石榴叶鞣质对高血脂小鼠糖代谢影响及其机制

目的：探讨石榴叶鞣质对高脂小鼠糖代谢的影响以及降糖的作用机制。方法：通过高脂饮食建立高脂并高血糖小鼠,灌胃石榴叶鞣质,观察小鼠血清糖脂的变化,肝糖元含量;通过体外HepG2细胞实验观察石榴叶鞣质对葡萄糖的利用及其胞内糖元含量变化。结果：灌胃石榴叶鞣质8周后,高脂小鼠外周血总胆固醇、甘油三酯和血糖均有明显降低,肝糖元升高;体外实验石榴叶鞣质可以明显促进HepG2细胞对葡萄糖的利用,增加胞内糖元含量。结论：石榴叶鞣质对高脂合并的高血糖有明显的降低作用,其作用机制可能与增加肝内糖元转化有关。     

石榴皮鞣质对大鼠乙醇性胃黏膜损伤的保护作用研究

目的:研究石榴皮鞣质对大鼠乙醇性胃黏膜损伤的保护作用。方法:乙醇灌胃(1.5mL/只)以复制大鼠乙醇性胃黏膜损伤模型。实验分为正常(等容生理盐水)、模型(等容生理盐水)、枸橼酸铋钾(100mg·kg-1)和石榴皮鞣质高、中、低剂量(500、150、50mg·kg-1)组,观察对胃黏膜的影响;测定一氧化氮(NO)、丙二醛(MDA)含量;通过免疫组化法测定神经元型一氧化氮合酶(nNOS)、内皮型一氧化氮合酶(eNOS)的表达。结果:150、500mg·kg-1石榴皮提取物可显著修复胃黏膜损伤,且可显著抑制模型大鼠MDA含量增高和NO含量降低(P<0.01),也可抑制nNOS、eNOS的表达下降,但无显著性差异。结论:石榴皮提取物对大鼠乙醇性胃黏膜损伤具有良好的保护作用,这种作用可能与抗脂质过氧化反应,抑制nNOS、eNOS表达下降有关。     

地榆中总鞣质超声提取工艺研究

目的:优选地榆中鞣质最佳提取工艺。方法:以提取物中总鞣质含量为指标,通过单因素试验研究提取溶剂、料液比、超声提取时间、超声提取次数等四个因素对总鞣质提取率的影响,利用正交试验确定地榆总鞣质最佳提取工艺。结果:地榆鞣质的最佳提取工艺为:12倍量的40%的乙醇,超声提取2次,每次75min。在最佳条件下,提取率为9.113%。结论:该工艺合理可行,重复性好,地榆鞣质的提取率高。     

玫瑰花提取物中鞣质含量测定

目的：建立玫瑰花提取物中鞣质的含量测定方法。方法：以没食子酸为对照品,采用磷钼钨酸一干酪素比色法测定。结果：在2．02～10．08μg·ml^-1范围内吸光度与鞣质含量呈良好的线性关系（r=0．9998）,平均回收率为100．14％（RSD=0．69％）。结论：本方法简便、准确,可用于玫瑰花提取物鞣质的含量测定。     

Antiepileptic potential of flavonoids fraction from the leaves of Anisomeles malabarica

Ethnopharmacological relevance

The plant Chodara (Anisomeles malabarica R.Br. Family: Lamiaceae) has numerous therapeutic utilities in folk medicine.

Aim of the study

To isolate and evaluate the anti-epileptic potential of fractions from the ethyl acetate extract (EAE) of Anisomeles malabarica leaves.

Materials and methods

The EA extract (2.12% w/w) of the leaves of Anisomeles malabarica was prepared and fractionated into total flavonoids fraction (AMFF) and tannins fraction (AMTF), which subsequently evaluated for the antiepileptic activity against PTZ- and MES model in wistar rats. Diazepam and phenytoin (2 mg/kg and 25 mg/kg, i.p., respectively), were used as a reference drugs. Further, the presence of flavonoid was confirmed by chemical test, TLC and HPTLC were done for the identification of the number of flavonoids with reference to standard.

Results

Single dose pretreatment with AMFF (25 and 50 mg/kg, i.p.) has found to be effective against both MES and PTZ-convulsions, but associated with a marked decrease in locomotor activity and motor activity performance (i.e., neurotoxic effects), similar to that of diazepam treatment. Interestingly, chronic treatment with AMFF at lower doses (6.25 and 12.5 mg/kg, i.p., 1 week) has also produced significant antiepileptic activity, but without causing neurotoxic effects.

Conclusion

Thus, it may be concluded that the flavonoids fraction of the EA extract of Anisomeles malabarica leaves has antiepileptic potential against both MES and PTZ convulsion models. Acute treatment (25 and 50 mg/kg, i.p.) is associated with neurotoxic activity. Whereas, chronic treatment (6.25 and 12.5 mg/kg, i.p., 1 week) also shown significant antiepileptic effect without causing neurotoxic side effects. However, further research is in progress to determine the component(s) of the flavonoids fraction of Anisomeles malabarica involved and their mechanism of action in bringing about the desirable anti-epileptic effect.     

The diarrhoeogenic and antidiarrhoeal bidirectional effects of rhubarb and its potential mechanism

Aim of the study

The present study investigated the pharmacological effects of different extracts of rhubarb on intestinal function of mice, further to explore possible reasons for the adverse effects of long-term use of rhubarb as a purgative.

Materials and methods

The total extract of rhubarb (TR) was extracted with 60% ethanol and the total anthraquinones extract (TA), total tannins extract (TT) and remaining components extract (RC) of rhubarb were separated from TR using macroporous resin. The pharmacological effects of each extract on the intestinal function of mice were evaluated by defecation test and the antidiarrhoeal activity of rhubarb tannins as well as its mechanism was studied by different animal models and histopathological examination.

Results

Both TR and TA produced purgative activities, but the purgative activity of TA was stronger than that of TR. Successive administration of TT produced an antidiarrhoeal activity in a time- and dose-dependent manner. Besides, successive administration of RC showed no significant effect on the intestinal function of mice. The antidiarrhoeal activity of rhubarb tannins was confirmed directly for the first time and its mechanism was probable that rhubarb tannins generated protein-precipitating reaction to the gastrointestinal mucosa due to its protein-precipitating action.

Conclusions

The results confirmed that rhubarb had the diarrhoeogenic and antidiarrhoeal bidirectional effects due to the coexistence of anthraquinones and tannins. The bidirectional effects might be the reason or one of the reasons for the adverse effects of long-term use of rhubarb as a purgative.     

Hymenaea stigonocarpa Mart. ex Hayne: A tropical medicinal plant with intestinal anti-inflammatory activity in TNBS model of intestinal inflammation in rats

Ethnopharmacological relevance

Stem bark and fruit pulp of Hymenaea stigonocarpa Mart ex. Hayne (Fabaceae) has been popularly used to treat inflammation and gastrointestinal diseases including ulcers, diarrhea and gastric pain. The aim of this study was to investigate the intestinal anti-inflammatory activity of a methanol extract derived from the stem bark and diet with fruit pulp of Hymenaea stigonocarpa in the TNBS model of intestinal inflammation in rats.

Material and methods

The intestinal anti-inflammatory activity of stem bark extract (100, 200 and 400 mg/kg) and fruit pulp (10% and 5% in diet) was measured against the intestinal inflammatory process induced by TNBS (trinitrobenzesulphonic acid) in rats. The protective effects were evaluated as follows: evaluation of intestinal damage (damage score, extension of lesion, colon weight/length ratio), incidence of diarrhea and adherence to adjacent organs, colon glutathione (GSH) and malondialdehyde (MDA) contents, myeloperoxidase (MPO) and alkaline phosphatase (AP) activities. In addition, in vitro studies on lipid peroxidation in rat brain membranes and phytochemical profile were performed with both stem bark and fruit pulp.

Results

Treatment with 100, 200 and 400 mg/kg of stem bark extract and 10% fruit pulp flour showed protective effects in the TNBS-induced colon damage, which was related to inhibition of MPO and AP activities, reduction in colon MDA content, and counteraction of GSH depletion induced by inflammatory process. A concentration-dependent inhibitory effect on the lipid peroxidation in rat brain membranes for stem bark and fruit pulp was determined, with an IC₅₀ value of 5.25±0.23 μg/mL and 27.33±0.09 μg/mL, respectively. Similar phytochemical composition was observed in fruit and stem bark, including mainly flavonoids, condensed tannins and terpenes.

Conclusions

Stem bark extract and fruit pulp flour of Hymenaea stigonocarpa prevented TNBS-induced colonic damage in rats and this protective effect were associated to an improvement of intestinal oxidative stress. The observed anti-inflammatory and antioxidant effects may be associated to the presence of flavonoids and tannins in the stem bark and fruit pulp of Hymenaea stigonocarpa.