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1.
CH(2)Cl(2) fraction obtained from the stem bark of Mammea africana inhibited noradrenaline (NA) or KCl-induced contraction in isolated guinea pig and rat aorta. The vasorelaxant potency of the CH(2)Cl(2) fraction of Mammea africana was diminished by a pre-treatment with Nitro-L-arginine methyl ester (L-NAME), an inhibitor of NO synthase, which was however not affected by indomethacin pre-treatment. These findings indicated that the vasorelaxant effect of Mammea africana may be partially endothelium dependent, mediated by nitric oxide and that vasoactive prostanoids might not be contributing to the vasorelaxation effect. Three bioactive compounds were isolated from this CH(2)Cl(2) fraction and identified as 4-n-propylcoumarins (1) (mammea B/BB), 4-phenylcoumarins (2) (mammea A/AA or mammeisin) and (B/BA) (3) and might involved in the vasorelaxant effect of the extract. The mechanisms of the vasorelaxant effect might therefore be multiple, including endothelium dependence and the mechanisms, which interfere with the liberation of Ca(2+) into the muscle cell.  相似文献   

2.
Brillantaisia nitens Lindau (Acanthaceae) is traditionally used in Cameroon for the treatment of many diseases including cardiovascular disorders. We have studied its vasorelaxant effects in rat vascular smooth muscle. In this study, aqueous, methylene chloride, methanol, and methylene chloride/methanol leaves extracts of Brillantaisia nitens were tested for their relaxing ability in vitro. Strips of rat aorta, with or without intact endothelium, were mounted in tissue baths, contracted with KCl (60mM) or norepinephrine (10(-4)M), and then exposed to the plant extracts. These extracts exhibited concentration-dependent vasorelaxations of norepinephrine-induced contractions of intact aortic strips. The EC(50) were 0.42+/-0.01mg/ml (aqueous extract), 0.63+/-0.02mg/ml (methylene chloride extract), 0.73+/-0.02mg/ml (methanol extract) and 0.36+/-0.02mg/ml (methylene chloride/methanol extract). The methylene chloride/methanol (CH(2)Cl(2)/CH(3)OH) extract was the most potent relaxing extract. It caused a concentration-dependent and endothelium-independent relaxation of the rat aortic strips contracted by KCl or norepinephrine. On the NE-induced contraction, its maximal relaxant activity (109%) due to the dose of 1.5mg/ml, was not significantly modified by the pretreatment of aortic strips with indomethacin (89%, P>0.05) or with l-NAME (103%, P>0.05). This suggests that the vasorelaxation elicited by CH(2)Cl(2)/CH(3)OH extract was not mediated via endothelium-derived prostacyclin or nitric oxide. In contrast, this relaxation was markedly reduced by tetraethylammonium, a blocker of non-selective K(+) channels and glibenclamide, a blocker of ATP-sensitive K(+) channels. The CH(2)Cl(2)/CH(3)OH extract significantly inhibited Ca(2+)-induced concentration-contraction and the Ca(2+) influx in aortic strips incubated with 60mM KCl. These results indicate that the vasorelaxant effect of the CH(2)Cl(2)/CH(3)OH extract of Brillantaisia nitens is due to an inhibition of Ca(2+) influx, possibly via the activation of ATP-sensitive K(+) channels.  相似文献   

3.
The aims of the present study were to investigate the vasoactive effects of ethyl acetate extract from Flos Chrysanthemi (FCE) and its mechanisms on the rat thoracic aorta. FCE (9.4-150 mg/L) caused a concentration-dependent relaxation on endothelium-intact rings precontracted with phenylephrine (PE, 10(-6)M) or a high level of K+ (6x10(-2)M). By removal of endothelium, the effect was not abolished but reduced significantly. N(G)-nitro-l-arginine methyl ester (l-NAME) (10(-4) M), methylene blue (10(-5) M) significantly inhibited the effect of FCE. Meanwhile, NO synthase of aorta in FCE group was markedly elevated versus the control. However, indomethacin did not influence FCE effect. SKF-525A combined with l-NAME had the same effect as l-NAME. Tetraethylammonium, BaCl2, 4-aminopyridine, 5-HD and propranolol also did not influence the vascular effect of FCE, but glibenclamide significantly attenuated its vasodilation. FCE did not reduce PE-induced transient contraction in Ca(2+)-free medium, but inhibited PE-induced contraction in K(+)-free solution or Ca2+ caused contraction after PE induced a stable contraction in Ca(2+)-free solution. It is concluded that FCE induced both endothelium-dependent and -independent relaxation. NO and cGMP-mediated pathway are likely involved in the endothelium-dependent relaxation, whereas inhibition of voltage-dependent Ca2+ channel, receptor-operate Ca2+ channel and activation of K(ATP) contribute in part to the endothelium-independent relaxation.  相似文献   

4.

Ethnopharmacological relevance

Solanum torvum fruits are commonly used in Cameroonian traditional medicine for treatment of arterial hypertension. It has been previously shown that intravenous administration of aqueous extract from dried fruits (AEST) reduced blood pressure.

Aim

The present work evaluates acute toxicity and effects of oral administration of AEST in chronic arterial hypertension induced by l-NAME. Effects of AEST were also evaluated on isolated aorta.

Materials and methods

AEST (200 mg/kg/day, p.o.) was given solely or concomitantly with l-NAME (40 mg/kg/day, p.o.) for 30 consecutive days. Animal body weight, systolic blood pressure and heart rate were measured before stating the treatment and at the end of each week. Urinary volume and urinary sodium and potassium contents were quantified before and at days 1, 15 and 30 of the treatment. Aorta from treated animals was tested for their sensitivity to noradrenalin and carbachol. Aorta from normal untreated rats was used to evaluate the in vitro vascular effect of AEST.

Results

The results showed that AEST did induce neither mortality nor visible signs of toxicity. When given solely or in co-administration with l-NAME, AEST significantly reduced animal's body weight. It amplified the hypertensive and cardiac hypertrophy effect of l-NAME and did not affect these parameters in normotensive animals. AEST increased the sensitivity to noradrenalin in normotensive and significantly reduced it in hypertensive animals. AEST significantly increased urinary volume and sodium excretion in l-NAME treated animals while reducing the sodium excretion in normotensive. In vitro, AEST induced a potent partial endothelium-dependent contraction of aortic ring; contractions that were partially antagonized by prazosin and verapamil and were not relaxed by carbachol.

Conclusion

These results suggest that oral chronic administration of AEST induced potentiation of arterial hypertension and cardiac hypertrophy in l-NAME treated rats. These effects may result from a reduction in sensitivity to vasorelaxant agents and increase in hypersensitivity to contractile factors. AEST possess potent in vitro vasocontractile activity that may result from activation of both α1-adrenergic pathway and calcium influx.  相似文献   

5.
The methanol extract of Xylocarpus granatum bark was studied for its antidiarrhoeal properties in experimental diarrhoea, induced by castor oil and magnesium sulphate in mice. At the doses of 250 and 500 mg/kg per oral, the methanol extract showed significant and dose-dependent antidiarrhoeal activity in both models. The extracts also significantly reduced the intestinal transit in charcoal meal test when compared to atropine sulphate (5 mg/kg; i.m.). The results showed that the extracts of Xylocarpus granatum bark have a significant antidiarrhoeal activity and supports its traditional uses in herbal medicine.  相似文献   

6.

Aim of the study

The stem bark of Mammea africana Sabine (Guttiferae) is used in African rain forest to treat various diseases, including diabetes mellitus. We investigated whether Mammea africana extract induced hypoglycaemic activity in rats.

Materials and methods

We tested the effects of acute (5 h) and sub-acute (21 days) oral administrations of the CH2Cl2–MeOH stem bark extract of Mammea africana (19–300 mg/kg body weight) on blood glucose levels of normal and streptozotocin (STZ)-induced type 1 diabetic rats. The effects were compared with those of glibenclamide.

Results

Acute administration reduced blood glucose in the diabetic rats only (33.87%, P < 0.01). Sub-acute treatment for 21 days also reduced blood glucose level in diabetic rats (73.29%, P < 0.01). A reduction or stabilization in total serum protein, triglyceride, cholesterol and alanine amino transferase levels was also observed. No effect was observed on body weight loss but food and water intakes were significantly reduced (P < 0.01) in diabetic rats. The maximal anti-diabetic effect was obtained with the dose of 75 mg/kg and was more important than that of glibenclamide.

Conclusion

It can be concluded that extracts of Mammea africana exhibited a significant anti-hyperglycaemic activity and improved the metabolic alterations in STZ-diabetic rats. These results provide a rationale for the use of Mammea africana to treat diabetes mellitus and hypercholesterolemia.  相似文献   

7.
Kalanchoe crenata Andr. (Crassulaceae) is a fleshy herbaceous plant used in the African traditional medicine as remedies against otitis, headache, inflammations, convulsions and general debility. In the present work, the analgesic effects of methylene chloride/methanol (1:1) (CH(2)Cl(2)/CH(3)OH) extract and its hexane, methylene chloride (CH(2)Cl(2)), ethyl acetate, n-butanol fractions and aqueous residue have been evaluated using acetic acid, formalin and pressure test. The anticonvulsant effects of the CH(2)Cl(2)/CH(3)OH extract were also investigated on seizures induced by pentylenetetrazol (PTZ 70 mg/kg), strychnine sulphate (STN 2.5 mg/kg) and thiosemicarbazide (TSC 50 mg/kg). CH(2)Cl(2)/CH(3)OH extract and its fractions, administered orally at the doses of 150 and 300 mg/kg, exhibited protective effect of at least 30% on the pain induced by acetic acid. The CH(2)Cl(2) fraction at 300 mg/kg showed a maximal effect of 78.49%. The CH(2)Cl(2)/CH(3)OH extract and its CH(2)Cl(2) fraction at the doses of 150 and 300 mg/kg significantly reduced the first phase of pain induced by formalin while the second phase was completely inhibited. The CH(2)Cl(2) fraction produced more than 45% reduction in the sensitivity to pain induced by pressure. The CH(2)Cl(2)/CH(3)OH extract of Kalanchoe crenata significantly increased the latency period in seizures induced by PTZ and significantly reduced the duration of seizures induced by the three convulsant agents. The extract protected 20% of animals against death in seizures induced by TSC and STN. These results suggest a peripheral and central analgesic activities as well as an anticonvulsant effect of the leaves of Kalanchoe crenata.  相似文献   

8.
The bark of Terminalia arjuna is in clinical use for the management of cardiovascular disorders in India. The objective of this study was to investigate the contractile response induced by the extract on rat aorta, a vascular smooth muscle. Terminalia arjuna relaxed the contraction, induced by both KCl (60 mM ) and norepinephrine (NE, 3 μM ). Inhibition was more prominent (80%) in the NE induced contraction than the KCl induced contraction (30%). Under similar conditions diltiazem, a calcium channel blocker (Dz, 1.0 μM ), inhibited 68% of the KCl induced and 30% of NE induced contraction. Thus it appears that the action of Terminalia arjuna extract differs from that of diltiazem in that it is more specific for alpha-adrenergic receptor agonists. It indirectly inhibited the contraction induced by norepinephrine by acting on K (Ca) channel by hyperpolarizing the smooth muscle membrane.  相似文献   

9.

Aim of the study

The stem bark of Terminalia superba (Combretaceae) (TS) is used in traditional Cameroonian medicine as antihypertensive remedy. In the present study, we investigated the vasorelaxant properties of different extracts of TS and their underlying mechanisms.

Materials and methods

Activities of aqueous (AQU), methanolic (MET), methylene chloride (MC), and methylene chloride–methanol (MCM) extracts of TS were evaluated on isolated rat aortic rings precontracted with phenylephrine (PE) or high KCl.

Results

All extracts induced a vasodilating effect both on KCl- and PE-induced contractions. The effects of MC and MCM extracts were greater than those of AQU or MET extracts (P < 0.05). MC had an endothelium-independent effect and reduced Ca++-induced contraction following PE or KCl challenge (P < 0.05). After incubation with verapamil, MC induced a relaxation in rings precontracted by PE (P < 0.001). By contrast, the effect of MCM was endothelium-dependent and decreased by the nitric oxide synthase inhibitor NW-nitro-l-arginine methyl ester (P < 0.05).

Conclusions

These data demonstrate that the MC extract exhibits vasorelaxant effects that are partly due to inhibition of extracellular Ca++ influx and/or inhibition of intracellular Ca++ release in vascular smooth muscle cells. By contrast, the effect of the MCM extract was found to be endothelium- and nitric oxide dependent.  相似文献   

10.
The antiulcerogenic effects of the bark methanol extract of Voacanga africana were studied using various experimental ulcer models in rats. The effects of the extract on the volume of gastric juice, gastric pH, acid output, mucus production and peptic activity were recorded, as well as the preventive action against lesions caused by HCl/ethanol and indomethacin. Oral administration of the extract (500-750 mg/kg) inhibited the formation of gastric lesions induced by HCl/ethanol (40-63% inhibition). The inhibitory effect against HCl/ethanol was significantly (P<0.01) suppressed by pre-treatment of the rats with indomethacin (30 mg/kg, i.p.). The extract significantly reduced gastric lesion formation in pylorus ligated rats, but this was not associated with an increase in gastric mucus production or with a reduction in acid content, volume of gastric secretion or pepsin activity of the gastric juice.  相似文献   

11.
AIM OF THE STUDY: Nine plants from Reunion Island, selected using ethnopharmacology and chemotaxonomy, were investigated for their potential antimalarial value. MATERIALS AND METHODS: Thirty-eight extracts were prepared by maceration using CH(2)Cl(2) and MeOH, and were tested for in vitro activity against the 3D7 and W2 strain of Plasmodium falciparum. The most active extracts were then tested for in vitro cytotoxicity on human WI-38 fibroblasts to determine the selectivity index. Those extracts were also investigated in vivo against Plasmodium berghei infected mice. RESULTS: Most active of the extracts tested were the dichloromethane leaves extracts of Nuxia verticillata Lam. (Buddlejaceae), Psiadia arguta Voigt. (Asteraceae), Lantana camara L. (Verbenaceae), the methanol extracts from Aphloia theiformis (Vahl) Benn. (Aphloiaceae) bark, and Terminalia bentzoe L. (Combretaceae) leaves displaying in vitro IC(50) values ranging from 5.7 to 14.1mug/ml. Extracts from Psiadia, Aphloia at 200mg/(kgday) and Teminalia at 50mg/(kgday) also exhibited significant (p<0.0005) parasite inhibition in mice: 75.5%, 65.6% and 83.5%, respectively. CONCLUSION: Two plants showed interesting antimalarial activity with good selectivity: Aphloia theiformis and Terminalia bentzoe. Nuxia verticillata still needs to be tested in vivo, with a new batch of plant material.  相似文献   

12.

Aim of the study

Tanacetum vulgare L. (Asteraceae/Compositae) is principally used in traditional Moroccan medicine as antihypertensive remedy. The aim of the present study was to investigate the in vitro vascular activity of the aqueous extract of Tanacetum vulgare L.

Materials and Methods

The activity of Tanacetum vulgare L. extract was tested on contractile response of Wistar rat aorta to high KCl and noradrenaline and on endothelium-dependent relaxation evoked by acetylcholine.

Results

The addition of Tanacetum extract during the plateau phase of noradrenaline-evoked contraction produced a rapid relaxation that reached a maximum of 30% of the contraction and was suppressed by the NO synthase inhibitor NG-nitro-l-arginine. At higher extract concentrations this rapid relaxation was followed by a slowly developing, NG-nitro-l-arginine-resistant, relaxing effect. Tanacetum extract also depressed KCl-evoked contraction by 30% at maximum. This effect was abolished in the presence of NG-nitro-l-arginine. The endothelium-dependent relaxation induced by acetylcholine was depressed in the presence of Tanacetum extract in the bathing solution.

Conclusion

:This study indicates that the aqueous extract of Tanacetum possesses NO-mediated and NO-independent vasorelaxing properties in vitro.  相似文献   

13.
Acanthus montanus is a plant used in Cameroon to treat pains and threatened abortion. The aim of this study was to evaluate the influence of methanol/methylene chlorides leaves extract from Acanthus montanus on Wistar pregnant rats and identify the substance(s) essential for these actions. Dams were treated orally from days 6 to 15 of the pregnancy at the dose levels of 0, 250, 500 and 1000 mg/(kgday). They were sacrificed on day 20 or allowed to deliver and wean. Various parameters were assessed. The F(1) generation offsprings were allowed to give birth to F(2) generation and a number of parameters assessed. The results showed that there was no maternal or organs toxicity. Embryotoxicity was observed during organogenesis manifested by reduction in foetal body weight, crown-rump and tail lengths and reduced ossification of extremities bones. However after delivery, these signs of growth retardation were seen before day 5, and henceforth, the treated pups regained all their parameters to normality. All others parameters for F(1) and F(2) generations were insignificant. beta-Sitosterol was the major chemical component of the extract and its role on these results could not be ignored. The MeOH/CH(2)Cl(2) extract of this plant is embryotoxic peri-natally at high doses but this failed to manifest after 5 days of post-natal survival. beta-Sitosterol may be central in the observed effects of the extract. This extract can be tolerated by pregnant patients.  相似文献   

14.
THE AIM OF THIS STUDY: was to assess the anti-inflammatory and mechanism of action of Allanblackia monticola (Guttiferae). The anti-inflammatory activity "in vivo" of the methylene chloride/methanol extract, methanol and methylene chloride fractions of stem barks of Allanblackia monticola, administered orally at doses of 37.5; 75; 150 and 300 mg/kg, was evaluated on carrageenan-induced oedema in rats to determine the most active fraction. Indomethacin, inhibitor of cyclo-oxygenase was used as reference drug. The effects of the most active fraction were then examined on the rat paw oedema caused by histamine, serotonin, arachidonic acid and dextran followed by its ulcerogenic effect. The results showed that the methylene chloride fraction of Allanblackia monticola was more effective on the oedema caused by the carrageenan. The anti-nociceptive activity of the methylene chloride fraction was assessed using the acetic acid-induced abdominal constriction model, formalin test and hot plate test. At 150 mg/kg, Allanblackia monticola caused maximum inhibitions of inflammation induced by carrageenan (83.33%), by histamine (42.10%), by dextran (40.29%) and by arachidonic acid (64.28%). Allanblackia monticola (75-300 mg/kg) did not cause significant modification of the oedema induced by serotonin. Concerning the anti-nociceptive properties of the plant, the methylene chloride fraction (75-300 mg/kg) caused a dose-dependent inhibition on abdominal contractions induced by acetic acid (32.34-77.37%) and significantly inhibited the inflammatory pain caused by formalin (40.71-64.78%). Allanblackia monticola did not increase the latency time in the hot plate test. Like indomethacin (10mg/kg), the fraction at the dose of 150 mg/kg caused ulceration of the gastric mucous membrane in treated rats. These results show that Allanblackia monticola has an anti-inflammatory and analgesic activities with gastric ulcerative side effects.  相似文献   

15.
拳参正丁醇提取液对家兔胸主动脉条收缩的影响   总被引:5,自引:0,他引:5  
目的:研究拳参正丁醇提取液(PBNA)对家兔离体胸主动脉条的作用。方法:采用家兔离体胸主动脉条,高钾去极化后,以不同浓度CaCl2为刺激剂,观察PBNA对其量-效曲线的影响;以NE为血管收缩刺激剂,观察PBNA对内钙释放与外钙内流的影响。结果:(1)低剂量PBNA(0.1mg/ml)可抑制高钾去极化引起的动脉条收缩,使CaCl2量-效曲线右移,最大反应性降低,高剂量PBNA(0.4mg/ml)可增强高钾去极化引起的动脉条收缩;(2)低剂量的PBNA抑制NE诱导的内钙释放所致的血管收缩反应,而高剂量的PBNA增强NE诱导的内钙释放所致的血管收缩反应;各剂量的PBNA对复钙后NE所致的血管收缩作用具有抑制趋势。结论:不同浓度的PBNA通过抑制或促进平滑肌细胞膜电压依赖Ca2 通道而对家兔主动脉条的收缩起双重效应,PBNA对受体操纵的Ca2 通道也具有一定的抑制作用,对K 通道的开放有一定的促进作用。  相似文献   

16.
Hypertension induced by nitric oxide synthase inhibition is associated with functional abnormalities of the heart and kidney. The aim of the present study was to investigate whether chronic treatment with Arbutus unedo leaf (AuL) or root (AuR) aqueous extracts can prevent these alterations. Six groups of rats were used: control group received tap water; N(G)-nitro-l-arginine methyl-ester (L-NAME) group treated with L-NAME at 40 mg/kg/day; AuL and AuR groups received simultaneously L-NAME (40 mg/kg/day) and Au leaves or roots extract at the same concentration 250 mg/kg/day; l-arginine and enalapril groups received simultaneously L-NAME (40 mg/kg/day) and l-arginine at 50mg/kg/day or enalapril at 15 mg/kg/day. Treatment of rats during 4 weeks with L-NAME caused an increase of the systolic blood pressure (SBP) accompanied by a ventricular hypertrophy, an impairment of endothelium-dependent vasorelaxation, an increase of the cardiac baroreflex sensitivity and a decrease of water, sodium and potassium excretion. The co-administration of AuL or AuR extracts with L-NAME reduces the development of increased SBP, ameliorates the vascular reactivity as well as the baroreflex sensitivity and normalizes the renal function. AuR reduces the ventricular hypertrophy but AuL do not. Enalapril associated with L-NAME reverses the majority of alterations induced by L-NAME while l-arginine only lightly ameliorates the vascular reactivity. These results show that chronic treatment with Arbutus extract regress the development of hypertension and ameliorate cardiovascular and renal functions in NO deficient hypertension.  相似文献   

17.
Sclerocarya birrea (Anacardiaceae) is used as a traditional treatment of diabetes in Cameroon. In this study, we investigated the possible antidiabetic effect of the stem bark extract in diabetic rats. Diabetes was induced by intravenous injection of streptozotocin (STZ, 55 mg/kg) to male Wistar rats. Experimental animals (six per group), were treated by oral administration of plant extract (150 and 300 mg/kg body weight) and metformin (500 mg/kg; reference drug) for comparison, during 21 days. The stem bark methanol/methylene chloride extract of Sclerocarya birrea exhibited at termination, a significant reduction in blood glucose and increased plasma insulin levels in diabetic rats. The extract also prevented body weight loss in diabetic rats. The effective dose of the plant extract (300 mg/kg) tended to reduce plasma cholesterol, triglyceride and urea levels toward the normal levels. Four days after diabetes induction, an oral glucose tolerance test (OGTT) was also performed in experimental diabetic rats. The results showed a significant improvement in glucose tolerance in rats treated with Sclerocarya birrea extract. Metformin, a known antidiabetic drug (500 mg/kg), significantly decreased the integrated area under the glucose curve. These data indicate that Sclerocarya birrea treatment may improve glucose homeostasis in STZ-induced diabetes which could be associated with stimulation of insulin secretion.  相似文献   

18.

Aims of the study

Gynura procumbens (Merr.), which is known as “Sambung nyawa”, is widely used in South East Asian countries in the traditional treatment of many ailments. However, there is little toxicological information available regarding safety following repeated exposure.The present investigation describes the toxicity of a methanol extract of Gynura procumbens leaves in rats.

Materials and methods

For acute toxicity studies, a methanol extract of Gynura procumbens was orally administered to Sprague–Dawley rats (female and male) at a dose range of 1000–5000 mg/kg. For sub-chronic toxicity studies, the rats were orally administered the methanol extract of Gynura procumbens at the doses of 125, 250, and 500 mg/(kg day) for a period of 13 weeks. The animals were sacrificed, followed by examination of their organs and blood serum.

Results and conclusions

Administration of the methanol extract from Gynura procumbens leaves at 1000–5000 mg/kg did not produce mortality or significant changes in the general behaviour, body weight, or organ gross appearance of rats. There were no significant differences in the general condition, growth, organ weights, haematological parameters, clinical chemistry values, or gross and microscopic appearance of the organs from the treatment groups as compared to the control group. Therefore, the NOAEL for the Gynura procumbens methanol extract is 500 mg/(kg day) administered orally for 13 weeks.  相似文献   

19.

Ethnopharmacological relevance

Artemisia ludoviciana spp. mexicana (Willd. Ex.) Spring D.D. Keck (Asteraceae), known as “estafiate” is employed for the treatment of diarrhea, dysentery, parasites, abdominal pain, vomiting, stomach ache, and also as antispasmodic agent. The aim of the present study was to evaluate the relaxant effect of hexanic (HEAl), dichloromethanic (DEAl) and methanolic (MEAl) extracts on isolated trachea, ileum and aorta rat rings, and to establish the tracheo-relaxant mode of action of DEAl.

Materials and methods

All extracts were investigated based on their capacity of to inhibit the rat ileum spontaneous contraction, to relax contraction induced by noradrenaline (0.1 μM) on endothelium-intact and endothelium-denuded thoracic aorta rat rings, and also to inhibit contraction provoked by carbachol (1 μM) on rat trachea.

Results

Organic extracts had no spasmolytic action on ileum strips compared to positive control (papaverine, p < 0.05). On the other hand, all extracts induced a significant concentration- and partial endothelium-dependent vasorelaxant activity. Extracts also showed significant relaxant effect on pre-contracted tracheal tissue in a concentration-dependent manner. In last two experiments, DEAl was the most potent and efficient extract; however, it was less potent than papaverine and theophylline, used as positive controls (p < 0.05). In tracheal preparation, DEAl shifted to the right, in a parallel manner, the concentration-response curves induced by carbachol (p < 0.05). Also, DEAl induced a significant relaxant effect on the contraction produced by potassium chloride (KCl, 80 mM). Pre-incubation with 1-H-[1,2,4]-oxadiazolo-[4,3a]-quinoxalin-1-one (ODQ, 10 μM), indomethacin (10 μM), Nω-nitro-l-arginine methyl ester (l-NAME, 10 μM), glibenclamide (10 μM) and 2-aminopyridine (2-AP, 100 μM) did not modify the DEAl-relaxant curves.

Conclusions

Functional experiments suggest that the most active extract, DEAl, induced its relaxant effect by possible muscarinic receptors antagonism and calcium channel blockade in tracheal rings. On the other hand, significant vasorelaxant activity showed by DEAl is partially endothelium-dependent. Finally, spasmolytic activity induced by the extracts in the rat ileum was not significant, which suggests that the antidiarrheic effect of the plant is related to antimicrobial and antiparasitic properties previously described.  相似文献   

20.
The anti-inflammatory activity of hexane leaf extract of Aspilia africana C.D. Adams (Compositae) was evaluated in rodents using the xylene-induced ear edema, egg albumin- and agar-induced paw edema, formaldehyde-induced arthritis, cotton pellet granuloma, gastric ulcerogenic, acetic acid-induced vascular permeability and dextran-induced in vivo leukocyte migration tests. Results showed that the extract (5mg/ear) inhibited topical edema in the mouse ear and at 200 and 400mg/kg (i.p.), it significantly (P<0.05) suppressed the development of egg albumin- and agar-induced paw edema, and the global edematous response to arthritis induced by formaldehyde in rats. Oral administration of the extract (200 or 400mg/kg) evoked a significant (P<0.05) dose-related ulceration of the rat gastric mucosa and inhibition of vascular permeability induced by acetic acid in mice. The extract also significantly (P<0.05) reduced total leukocyte and neutrophils counts in a non-dose-related manner. However, it significantly (P<0.05) increased lymphocyte counts and stimulated the growth of granuloma tissues induced by subcutaneously implanted cotton pellets in rats. Phytochemical tests showed that the extract contained sterols and terpenoids. These findings suggest that the leaves of Aspilia africana possess anti-inflammatory activity in acute and certain aspects of chronic inflammation, which may derive from inhibition of prostaglandins synthesis, inhibition of increased vascular permeability, inhibition of neutrophil migration into inflamed tissues, and stimulation of lymphocyte accumulation, which may enhance tissue repair and healing. The terpenoids present in the leaves may account for the anti-inflammatory activity.  相似文献   

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