银杏叶提取物的心肌延迟保护作用及其机制研究

目的观察银杏叶提取物(EGb761)对大鼠离体心脏心肌的延迟保护作用及其机制。方法离体大鼠心脏全心停灌缺血30min后再灌注30min产生缺血再灌损伤,观测心率(HR)、冠脉流量(CF)、左室内压(LVP)和左室内压变化最大速率( dp/dtmax),测定心肌组织中肌酸激酶(CK)释放量、心肌组织丙二醛(MDA)和一氧化氮(NO)的量。结果实验前24h单次ig给予EGb761(50或100mg/kg)可显著改善心肌缺血再灌注所致的心功能(LVP和 dp/dtmax)损伤,抑制心肌组织CK释放和MDA水平的增加以及NO水平的降低。预先给予NO合酶抑制剂L-NAME(5mg/kg)或心肌肌细胞膜ATP敏感钾通道(sarcKATP)阻断药HMR1883(3mg/kg),均可明显抑制EGb761对心肌缺血再灌注损伤的延迟保护作用。结论EGb761对缺血再灌注诱导大鼠心肌损伤具有延迟性保护作用,这一保护作用可能与增加NO合成和开放sarcKATP通道有关。     

Hypotensive effect of crude root extract of Solanum sisymbriifolium (Solanaceae) in normo- and hypertensive rats

The hypotensive effect of the crude hydroalcoholic extract from root of Solanum sisymbriifolium Lam. (Solanaceae) was investigated both in normotensive and hypertensive rats. The intravenous administration of the extract (50 and 100 mg/kg) produced a significant decrease in blood pressure in anaesthetized hypertensive (adrenal regeneration hypertension + deoxycorticosterone acetate (ARH + DOCA)) rats. Oral administration of the extract (10, 50, 100 and 250 mg/kg) also produced a dose-dependent hypotensive effect in conscious hypertensive animals. In anaesthetized normotensive rats, the extract (50 and 100 mg/kg, i.v.) also induced hypotension in a dose-dependent manner. Lastly, no significant effect on blood pressure was produced by the extract when administered orally (10, 50, 100, 250, 500 and 1000 mg/kg) to conscious normotensive rats.     

Possible mechanisms of action of the neutral extract from Bidens pilosa L. leaves on the cardiovascular system of anaesthetized rats

The aim of this study was to investigate the hypotensive and cardiac effects of the neutral extract from Bidens pilosa leaves. Intravenous administration of the extract resulted in a biphasic dose-related hypotensive activity. In normotensive rats (NTR), B. pilosa decreased systolic blood pressure by 18.26%, 42.5% and 30% at doses of 10, 20 and 30 mg/kg, respectively. In spontaneously hypertensive rats (SHR), the decrease in systolic blood pressure was 25.77%, 38.96% and 28.64% at the above doses, respectively. These doses induced hypotension by 27%, 34.13% and 18.73% respectively in salt-loaded hypertensive rats. In NTR, B. pilosa reduced heart rate by 23.68% and 61.18% at doses of 20 and 30 mg/kg, respectively. The force of contraction of the heart was only affected at 30 mg/kg. The initial phase of hypotensive response was partially inhibited by atropine while propranolol increased this effect. These results suggest that B. pilosa exhibited its fi rst hypotensive effects by acting on the cardiac pump efficiency and secondly through vasodilation.     

Hypotensive Activity of Lannea coromandelica Bark Extract

An ethanol extract of Lannea coromandelica bark (ELC) showed hypotensive activity in anaesthetized dogs and rats. On intravenous administration (i.v.) at a dose range of 5–100 mg/kg in dogs and 1–25 mg/kg in rats it produced a mild to marked decrease in the arterial blood pressure in a dose dependent manner. The effect did not alter after cholingergic, histaminergic, adrenergic and ganglion receptor blockade. The hypotension was also unchanged in vagotomized and eviscerated dogs, whereas there was a slight increase in hypotension in the spinal preparation. It produced dose related decreases in heart rate, without any effect on respiratory rate.     

Vasorelaxant and hypotensive effects of a hydroalcoholic extract from the fruits of Nitraria sibirica Pall. (Nitrariaceae)

Ethnopharmacological relevance

Fruits of Nitraria sibirica Pall. are traditionally used in Uighur medicine to treat hypertension. This study aimed to support that folk use by defining their vasoactive and hypotensive properties.

Materials and methods

The vasorelaxant activity and the underlying mechanisms of a hydroalcoholic extract from the fruits of Nitraria sibirica Pall. (NSHE) were evaluated on thoracic aortic rings isolated from Wistar rats. In addition, the acute hypotensive effect of NSHE was assessed in anesthetized spontaneously hypertensive rats (SHR) and in their normotensive control Wistar Kyoto (WKY) rats.

Results

NSHE (0.1–10 g/l) was clearly more effective to induce vasodilation of phenylephrine- (PE, 1 μM) than high KCl- (60 mM) pre-contracted aortic rings with respective E_max values of 82.9 ± 2.2% and 34.8 ± 3.6%. The removal of endothelium almost abolished the relaxant effect of the extract. In addition, pre-treatment with N^w-nitro-l-arginine-methyl ester (l-NAME, 100 μM), atropine (1 μM) or charybdotoxin (30 nM) plus apamin (30 nM), respective blockers of nitric oxide (NO) synthase, muscarinic receptors and endothelium-derived hyperpolarizing factor (EDHF), significantly reduced the observed effect of NSHE. By contrast, the cyclooxygenase (COX) inhibitor indomethacin (10 μM) or the K⁺ channels blockers glibenclamide (10 μM), iberiotoxin (30 nM) and 4-amino-pyridine (4-AP, 1 mM) failed to modify the vasodilation. Finally, the acute intravenous injection of NSHE (1, 5, 10, 20 mg/kg) induced an immediate and transient hypotensive effect in anesthetized SHR and in WKY rats.

Conclusions

This experimental animal study suggests that hydroalcoholic extract from the fruits of Nitraria sibirica Pall. induces vasorelaxation through an endothelium-dependent pathway involving NO synthase (NOS) activation, EDHF production and muscarinic receptor stimulation. Additionally, our results determine that this vasorelaxant effect is translated by a significant hypotensive effect.     

补肾活血浸膏的舒张血管作用及其机理研究

目的:通过观察补肾活血浸膏对豚鼠肠系膜微血管、大鼠胸主动脉环、门静脉环及其血浆的NO、血管的NO和NOS、cNOS、iNOS的影响,研究本方的舒张血管作用及其效应机制.方法:去甲肾上腺素致豚鼠肠系膜微血管收缩研究其整体的舒张血管作用;观察药物对苯肾上腺素收缩离体大鼠胸腔主动脉环或静脉环的作用,以及在预加优降糖或普萘洛尔或去血管内皮后其作用的影响;硝酸还原酶法测定给予药物后大鼠血浆和血管的NO及血管NOS、cNOS、iNSO的含量变化.结果:补肾活血浸膏有扩张去甲肾上腺素致豚鼠肠系膜微血管收缩的作用;松弛苯肾上腺素引起的离体大鼠胸腔主动脉环或静脉环的收缩作用,预加优降糖仍然有松弛作用.然而对预加普萘洛尔后补肾活血浸膏剂量低时保持舒张血管作用,剂量增加时反而引起收缩血管作用,大鼠胸腔主动脉环去内皮后药物无松弛作用,反而引起收缩作用;补肾活血浸膏高、低剂量组均能升高血浆NO水平,但只有高剂量组有显著性差异(P＜0.01);高、低剂量组均能显著性升高大鼠主动脉NO(P＜0.001,P＜0.05);高剂量组显著性升高NOS(P＜0.05)和cNOS(P＜0.001),低剂量组有升高NOS作用,但无显著性差异,对cNOS有显著性升高作用.结论:补肾活血浸膏的舒张血管作用机制与血管内皮释放NO和促进NOS、cNOS合成有关.     

Pharmacological effects of Eugenia uniflora (Myrtaceae) aqueous crude extract on rat's heart

The effect of aqueous crude extract (ACE) of Eugenia uniflora L. (Myrtaceae) was studied on rat's perfused ventricles. This plant is used in South American traditional medicine as an antihypertensive and we already demonstrated previously its hypotensive properties. In this paper, maximal left intraventriclular pressure (P) of rat's hearts beating at 0.2 Hz firstly increased to 162.1+/-11.1% of basal value during 1-3 min of perfusing ACE 0.6%. Maximum rate of contraction (+P) also increased to duplicating +P/P ratio. Both types of effect were significantly decreased by either propranolol 0.35 microM, and pre-treatment with reserpine (5 mg/kg), suggesting that they were caused by a compound that releases cathecolamines with beta-adrenergic action. Nevertheless, after 20 min of perfusing ACE, ventricles decreased P to about 50% of their basal value, suggesting a negative-inotropic compound present in the extract. The perfusion of 1.2% ACE decreased P in a pressure-[Ca](o) curve (0.5-2 mM) in a non-competitive manner, suggesting that an irreversible Ca-blocking compound is also present in the extract. In summary, E. uniflora ACE has a dual effect on the heart related to its hypotensive action and is probably responsible for the therapeutic or adverse effects in patients under cardiac risk.     

复方中药861对大鼠肝星状细胞系一氧化氮合酶表达及其活性的影响

目的：研究复方中药861对大鼠肝星状细胞系（HSC－T6）一氧化氮合酶（NOS）表达及其酶活性的影响，并探讨该药预防、治疗早期门脉高压的可行性。方法：细胞密度为1×10^5/ml的HSC－T6接种于细胞培养皿中，95％O2，5％CO2，37℃，培养24h进行以下分组实验，每组重复6皿，继续培养24h。1组：HSC－T6空白对照组；2组：HSC－T6加复方中药861（2mg/ml)；3组：HSC－T6加复方中药861（4mg/ml)；4组：HSC－T6加复方中药861（8mg/ml)；5组：HSC－T6加复方中药861（4mg/ml)加L－硝基精氨酸甲酯（L－NAME,4mg/ml)。采用化学比色法测定NOS活性，采用硝酸还原酶法测定培养液一氧化氮（NO）水平。4％多聚甲醛固定细胞2h，采用免疫细胞化学法观察HSC－T6诱导型一氧化氮合酶（iNOS)表达。结果：复方中药861能增加HSC－T6 NOS活性（P＜0．01），上清液NO水平也平行增加（P＜0．01），L－NAME不能抑制复方中药861刺激的HSC－T6合成、分泌NO增加（P＞0．05）。免疫细胞化学研究发现活化的HSC－T6细胞浆有iNOS表达，复方中药861能增加HSC－T6 iNOS表达。结论：活化HSC－T6iNOS表达阳性，与自分泌NO有关；复方中药861能明显增加HSC－T6iNOS表达及其酶活性，NO合成、分泌增加。复方中药861可能通过增加肝星状细胞分泌NO途径，抑制肝星状细胞的收缩，从而降低肝窦阻力。因此，复方中药861在预防、治疗早期门脉高压中可能具有重要作用。     

银杏提取物和潘生丁对兔心肌缺血再灌注后iNOS基因转录和翻译的影响

目的 研究银杏提取物（Egb761）与潘生丁单用及联用对家免心肌缺血再灌注诱导型一氧化氮合酶（iNOS）的影响。方法 参照文献方法制备兔缺血再灌注模型,35只兔随机分为5组,每组7只,假手术组、模型组、潘生丁（0．8mg／kg）组、银杏（Egb761 40mg／kg）组及联合组,于再灌注30min后分别静脉注射相应的药物,同时检测心肌再灌注晚期iNOS转录水平和翻译水平表达变化。结果 每组动物均存活至实验结束。心肌iNOS转录水平表达分别是假手术组0、模型纽157．11±17．73、潘生丁组202．6±21．84、银杏组356．13±24．18和联合组562．34±35．19,与模型组比较,各用药组心肌iNOS转录水平表达显著增加（P〈0．01）。心肌缺血再灌注中iNOS蛋白翻译水平表达分别是假手术组34．24±15．78、模型组75．70±13．71、潘生丁组116．89±22．57、银杏组143．75±16．05和联合组195．09±22．25,与模型组比较,各用药组iNOS蛋白翻译水平表达均显著增加（P〈0．05或P〈0．01）。结论 潘生丁与银杏提取物单用和联用均增加家兔心肌缺血再灌注晚期iNOS表达,联用增加更明显。     

Isolation of hypotensive compounds from Solanum sisymbriifolium Lam

The crude hydroalcoholic root extract (CRE) of Solanum sisymbriifolium Lam. has formerly been shown to have hypotensive activity both in normo-and hypertensive rats. Hypotensive activity-guided fractionation of the CRE was performed in anaesthetized normotensive rats, which led to the isolation of the active principles. The intravenous (i.v.) and intraperitoneal (i.p.) values of the CRE in mice were found to be, respectively, 343 and 451 mg/kg, and no lethal effect was caused by doses up to 5.0 g/kg when administered by oral route. Depression of locomotion, increase of breathing rate and piloerection was observed in a general behavior test with doses up to 200 mg/kg i.p., and 1000 mg/kg p.o., respectively. Increase in the gastrointestinal transit was found using 0.1 g/kg, whereas at doses of 0.5 and 1 g/kg, no significant activity was observed in comparison with the control mice. Hexanic and butanolic fractions induced a remarkable hypotension in anaesthetized normotensive rats in doses of 1, 5, 7.5 and 10 mg/kg i.v. Two compounds isolated from the butanolic fraction induced a significant decrease of the blood pressure, HR, amplitude of the ECG and breathing rate when injected in a dose of 1 mg/kg i.v; and both systofic and diastolic, blood pressures were affected in a proportional mode. The hypotensive effect of the two compounds were not influenced by pretreatment with atropine and propranolol; and the pressor response to noradrenaline was not affected by any of them which suggests that neither a direct muscarinic activity, β-adrenoceptor activation nor decrease of sympathetic vascular tone (sympatholitic activity) are probably involved in the mechanism of hypotension. The present study shows that the CRE of S. sisymbriifolium contains at least two hypotensive compounds whose characterization is under way.     

Cardiovascular effects of the South American medicinal plant Cecropia pachystachya (ambay) on rats

Cecropia pachystachya is used in South America for relieving cough and asthma. In Argentina it is known as "ambay" and grows in the neotropical forests (Ntr C.p.) and in temperate hilly regions (Tp C.p.). To evaluate their cardiovascular profile, the effect of extracts obtained from plants growing in the neotropical region as well as in temperate areas were compared by i.v. administration in normotensive rats. The following parameters were measured: blood pressure (BP) and heart rate (HR). The hypotensive effect was stronger for Ntr C.p., which aqueous extract decreased BP at doses between 90 and 300 mg lyophilised/kg until 46.2 +/- 12% of basal. The extract of Tp C.p. reduced BP to 86.1 +/- 11% of basal (p < 0.05 respect to Ntr C.p.) at 180 mg/kg, but increased HR at 90 and 180 mg/kg (until 133.6 +/- 10.8% of basal, p < 0.05) and produced death by respiratory paralysis at 320 mg/kg (about 3g dry leaves/kg). The hypotensive effects, but not the chronotropic ones, were attenuated by pretreatment with reserpine (5 mg/kg). The plant extracts had not diuretic activity by oral administration in conscious rats, nor produced vasodilation of perfused hindquarters arterial bed precontracted with high-[K] or 100 microM phenylephrine. The results suggest that neotropical ambay is more hypotensive than the one from the temperate hilly region. When it reaches plasma, it could produce hypotension (by central blockade of sympathic innervation of vessels) and tachycardia (by central cholinergic inhibition of heart), although it happens at doses higher than the oral ethnotherapeutic (about 340 mg dried leaves/kg).     

Autonomic nervous system mediates the cardiovascular effects of Rhodiola sacra radix in rats

ETHNOPHARMACOLOGICAL RELEVANCE: Rhodiola sacra (Crassulaceae) exhibits cardiovascular bioactivities and is used in Tibetan medicine for promoting circulation and preventing hypertension. However, the underlying mechanisms of its cardiovascular effects are poorly understood. AIM OF THE STUDY: The aim of this study was therefore to evaluate the cardiovascular activity of water-soluble fraction (WtF) and n-butanol-soluble fraction (BtF) of Rhodiola sacra radix and to explore its mechanism of action in propofol anesthetized Sprague-Dawley rats. MATERIALS AND METHODS: The changes of blood pressure, heart rate and cardiac contractility after systemic administration of the extracts (10-75mg/kg) were examined for at least 40min. Different antagonists were used to evaluate the mechanisms of cardiovascular effects of the extracts. RESULTS: Intravenous injection of the WtF (10, 25, 35, 50 or 75mg/kg) exhibited dose-dependent hypotension and increases in heart rate and cardiac contractility. In contrast, mild alterations in the same cardiovascular parameters were detected only at high dose (75mg/kg) BtF. The WtF-induced hypotensive, positive inotropic and chronotropic effects were significantly abolished by pretreatment with hexamethonium (30mg/kg, i.v.) or reserpine (5mg/kg, i.v.), whereas the hypotensive, but not the positive inotropic or chronotropic effect was potentiated by captopril (2.5mg/kg, i.v.). Pretreatment with methylatropine (1mg/kg, i.v.), on the other hand, reversed the positive inotropic and chronotropic but not the hypotensive effects of WtF. The WtF-induced cardiovascular responses were not affected in rats pretreated with N(G)-nitro-l-arginine methyl ester (20mg/kg, i.v.). CONCLUSIONS: We conclude that systemic administration of the WtF of Rhodiola sacra radix elicited a potent hypotensive effect that was mediated by the withdrawal of sympathetic vasomotor tone and interaction with the circulatory angiotensin system. The positive inotropic and chronotropic effects of WtF may result from a direct vagal inhibition on the heart.     

淡豆豉对心肌缺血小鼠心肌一氧化氮合酶表达的影响

目的:观察淡豆豉对心肌缺血小鼠心肌SOD、MDA、NO及iNOS表达的影响,探讨其抗心肌缺血机制。方法:将40只小鼠随机分为4组,分别为空白对照组、模型对照组、淡豆豉提取物小剂量(20 g生药/kg)治疗组及淡豆豉提取物大剂量(40 g生药/kg)治疗组。治疗组灌胃给予不同剂量的淡豆豉提取物,连续7天,7天后腹腔注射脑垂体后叶素20 U/kg,诱发心肌缺血。检测各组小鼠心肌SOD、MDA、NO及iNOS表达的变化。结果:模型对照组小鼠心肌、MDA含量明显较空白对照组升高,SOD、NO水平较空白对照组降低,心肌iNOS表达减弱,淡豆豉治疗组心肌SOD、NO含量显著较模型对照组提高,MDA明显较模型对照组降低,心肌iNOS表达增强。结论:淡豆豉提取物对心肌缺血有一定的保护作用,其机制与调节心肌iNOS表达有关。     

Hypotensive effect of Laurelia sempervirens (Monimiaceae) on normotensive rats

The leaves of Laurelia sempervirens (Monimiaceae), an endemic Chilean tree known as ‘Laurel’, were used by the Mapuche Amerindians for treating headache and as a diuretic. Intravenous administration of a hydroalcoholic L. sempervirens extract to rats, elicited a hypotensive response of ?27.0%±2.0% in the mean blood pressure of normotensive animals at a dose of 5 mg crude extract ± kg body weight. Bioassay-guided isolation of the active ‘Laurel’ metabolites led to the alkaloid laurotetanine as the main hypotensive principle of L. sempervirens leaves. At 1 mg/kg body weight, laurotetanine produced a hypotensive response of ?29.0%±2.1% in the mean blood pressure of normotensive rats, with a duration of 2 min, both comparable to those elicited by the crude extract at 5 mg/kg. In the acute oral toxicity study, ‘Laurel’ proved to be a very low toxicity crude drug at doses up to 3 g crude extract/kg body weight. The data obtained support the use of L. sempervirens in Mapuche traditional medicine.     

Cardiovascular effects of Tabernaemontana pandacaqui

Intravenous injection of ethanolic extracts of the stem, leaf and flower of Tabernaemontana pandacaqui caused hypotension in pentobarbital anesthetized rats. At high doses (100-300 mg/kg), the flower extract showed a transient hypertensive effect preceeding hypotensive activity. The effects of the extracts on the heart rate of anesthetized rats correlated well with the negative chronotropic and inotropic activity observed with isolated atrium. The hypotensive activity was not inhibited by antihistaminic and antimuscarinic agents. The extracts had no effect on the pressor effects induced by norepinephrine or dual carotid occlusion. These results suggest that the hypotensive action of the extracts is not mediated through histaminic and muscarinic receptors stimulation, alpha-adrenoceptor blockade or interference of sympathetic transmission.     

丹参酮ⅡA对脑缺血再灌注损伤大鼠脑组织及血清中NO含量及NOS、iNOS活性的影响

目的观察丹参酮Ⅱh（Tan ⅡA）对脑缺血再灌注损伤大鼠脑组织及血清中一氧化氮（NO）含量、一氧化氮合酶（NOS）及诱导型一氧化氮合酶（iNOS）活性的影响,探讨其对脑缺血再灌注损伤保护作用的可能机制。方法将大鼠随机分为假手术组、缺血再灌注组、Tan ⅡA低、高剂量组,线栓法建立局灶性脑缺血再灌注模型。Tan ⅡA高、低剂量组于术前连续灌胃给予高、低剂量Tan ⅡA 3d,每日1次。各组于脑缺血90min再灌注24h后进行HE染色,观察病理形态学变化,检测脑组织和血清中NO含量和NOS、iNOS活性的变化。结果Tan ⅡA高、低剂量组脑组织缺血损伤病理学改变明显轻于缺血再灌注组,Tan ⅡA高剂量组缺血改变亦轻于低剂量组。与假手术组比较,缺血再灌注组脑组织和血清中NO含量和NOS、iNOS活性明显升高;与缺血再灌注组比较,Tan ⅡA高、低剂量组脑组织和血清中N0含量和NOS、iNOS活性均明显降低,高、低剂量组之间差异具有统计学意义（P〈0．05）。结论Tan ⅡA可减轻神经元损伤程度,对缺血再灌注脑损伤具有保护作用,其机制可能与降低NOS、iNOS活性,减少NO含量有关。     

蛇毒三肽pENW对LPS诱导人脐静脉内皮细胞中NOS表达的影响

目的:探讨焦谷氨酸-天冬酰胺-色氨酸(蛇毒三肽p ENW)对体外脂多糖(LPS)诱导人脐静脉内皮细胞损伤的保护机制。方法:采用LPS(1 mg·L-1)模拟人脐静脉内皮细胞炎症损伤模型,实验分为空白组、LPS模型组、蛇毒三肽p ENW高、中、低剂量组(10-4,10-5,10-6mol·L-1)、N-甲基-L-精氨酸组(L-NMMA,5×10-4mol·L-1);除空白组外,其余各试验组加入LPS,蛇毒三肽p ENW高、中、低剂量组和L-NMMA组同时给予不同浓度的药物,孵育24 h后,采用噻唑蓝(MTT)比色法检测人脐静脉内皮细胞活力;Griess Reagent法用于检测一氧化氮(NO)的含量;比色法测定一氧化氮合酶(NOS)分型的活力;Western blot分析内皮型一氧化氮合酶(e NOS),诱导型一氧化氮合酶(i NOS)蛋白表达的变化。结果:与空白组比较,模型组LPS显著性损伤人脐静脉内皮细胞并诱导NO大量释放,t NOS,i NOS的活性明显增强(P0.01),i NOS蛋白表达显著上调(P0.01),e NOS的活性和蛋白表达并无差异;与模型组比较,蛇毒三肽p ENW高、中、低剂量能够剂量依赖性的抑制LPS对人脐静脉内皮细胞的损伤,并且能够明显降低NO的释放,同时,蛇毒三肽p ENW高、中、低剂量能够降低LPS诱导人脐静脉内皮细胞中的t NOS,i NOS的活性及i NOS的蛋白表达(P0.05,P0.01),与L-NMMA组作用一致,但蛇毒三肽p ENW对人脐静脉内皮细胞中e NOS的活性及蛋白表达无显著性影响。结论:蛇毒三肽p ENW可降低LPS对人脐静脉内皮细胞的损伤作用,其保护机制可能与逆转LPS诱导的i NOS蛋白表达上调及NO的释放相关。     

电针“内关”对内毒素休克鼠肝组织一氧化氮合酶活性的影响

目的 :观察电针“内关”对内毒素休克时肝功能的保护作用和肝组织一氧化氮合酶(NOS)表达的影响。方法 :静脉注射内毒素 (LPS) 1.5mg/kg、腹腔注射D 氨基半乳糖 (D GalN)10 0mg/kg造成内毒素休克模型 ,用电针“内关”和氨基胍 (AG)作对照干预处理 ,取血清检测肝功四项 ,用免疫组化方法检测诱生型一氧化氮合酶 (iNOS)、内皮型一氧化氮合酶 (eNOS)在肝组织内的表达。结果 :电针“内关”可以使肝功四项中ALT、AST、LDH值显著下降 ,使肝内iNOS表达减弱、eNOS表达增强 ,肝损害减轻。结论 :电针“内关”可以减轻内毒素休克造成的肝损害 ,这种保护作用可能是通过调节肝组织NOS表达而产生的     

杜鹃花总黄酮对在体大鼠心肌缺血再灌注损伤的保护作用及其机制

目的 观察杜鹃花总黄酮(TFRS)对大鼠心肌缺血再灌注损伤的保护作用及其机制.方法 采用在体结扎大鼠心脏冠状动脉左前降支法,观察心电图ST段和T波的变化,TTC染色法测定心肌梗死面积并测定大鼠血清乳酸脱氢酶(LDH)、肌酸激酶(CK)活性,血清丙二醛(MDA)及一氧化氮(NO)水平,并应用逆转录酶链式反应(RT-PCR)方法测大鼠心肌中诱导型一氧化氮合酶(iNOS)mRNA表达情况.结果 TFRS 100 mg/kg对缺血30 min时ST段的抬高有明显抑制作用,TFRS 25、50、100 mg/kg对再灌注30 min时ST段的抬高有明显抑制作用;TFRS 50 mg/kg能显著的降低心肌梗死面积;TFRS 50、100 mg/kg能不同程度降低血清中的LDH、CK的活性.TFRS 50 mg/kg可降低血清中MDA的水平;TFRS 100 mg/kg能显著提高心肌iNOS mRNA的表达.结论 TFRS对心肌和缺血再灌注损伤有一定的保护作用,其作用机制可能与抗自由基和提高心肌iNOS基因mRNA的表达及增加NO产生有关.     

Hancornia speciosa Gomes induces hypotensive effect through inhibition of ACE and increase on NO

Ethnopharmacological relevance

The leaves of Hancornia speciosa Gomes are popularly used in Brazil to treat diabetes and hypertension. Cardiovascular diseases are the main cause of death worldwide and their incidences are increasing in Brazilian population. The present study aimed to investigate the hypotensive effect and the mechanism of action of Hancornia speciosa Gomes.

Methods

A fraction of the ethanolic extract of leaves from Hancornia speciosa (SFH) was obtained and standardized by its content on rutin, bornesitol and quinic acid. Systolic blood pressure (SBP) of normotensive mice was measured by tail pletismography. SFH was given orally and SBP was monitored for 5 h. Angiotensin-converting enzyme (ACE) inhibitor activity of SFH (1 mg/kg) or captopril (10 mg/kg) was measured by colorimetric methods. Serum nitrite levels were measured by spectrophotometry.

Results

SFH induced a dose-dependent hypotensive effect in normotensive mice. The serum activity of ACE and the level of angiotensin II were significantly reduced by SFH and by captopril. Administration of SFH induced a significant increase on plasmatic level of nitrites and the systemic inhibition of nitric oxide synthase by L-NAME (20 mg/kg) reduced the hypotensive effect of SFH.

Conclusions

The present work demonstrated that Hancornia speciosa has a potent hypotensive effect in normotensive mice. The inhibition of ACE leading to reduction on angiotensin II and increase on NO levels might account for the hypotensive effect. These results support the use of Hancornia speciosa by traditional medicine as antihypertensive.