RESUMO
This study was undertaken to evaluate the effects of Aframomum melegueta on male rat ejaculation using in/ex copula techniques. For the in copula experiment, rats were orally treated with aqueous or methanolic extract (20 and 100 mg/kg) of A. melegueta for 14 days. Each rat was mated with a primed receptive female on days 0, 7 and 14 of treatment, and the ejaculatory latency and post-ejaculatory interval were measured. In the ex copula experiment, the electromyography of the bulbospongiosus muscles and intraseminal pressure were recorded in spinal rats after mechanical (urethral and penile) and pharmacological stimulations (intravenous injection of dopamine (5 mg/kg) and, aqueous or methanolic extract of A. melegueta, 2.5; 5; 10 and 20 mg/kg). Furthermore, the effect of dopamine on fictive ejaculation was monitored in rats orally pre-treated with A. melegueta extracts (20 and 100 mg/kg) for 7 or 14 days. Treatment with the aqueous or methanolic extract of A. melegueta significantly decreased the ejaculatory latency (p < .05) and post-ejaculatory interval (p < .01) after 14 days. In spinal rats, mechanical or pharmacological stimulations triggered fictive ejaculation. In animals orally pre-treated with A. melegueta extracts, the pro-ejaculatory effect of dopamine was more expressed. Present findings show that A. melegueta possesses pro-ejaculatory effects.
Assuntos
Ejaculação/efeitos dos fármacos , Extratos Vegetais/farmacologia , Comportamento Sexual Animal/efeitos dos fármacos , Zingiberaceae/química , Administração Oral , Animais , Dopamina/farmacologia , Feminino , Injeções Intravenosas , Masculino , Metanol/química , Modelos Animais , Ratos , Ratos Wistar , Água/químicaRESUMO
Background: Diarrheal diseases are a major cause of morbidity and mortality throughout the world and particularly in developing countries. Nauclea diderrichii is a plant used in traditional medicine in the treatment of anemia, fever, gastric ulcer, malaria, abdominal pain, skin infections, and diarrhea. The present work is aimed at evaluating the antisecretory and spasmolytic activities of aqueous and ethanolic stem bark extracts of Nauclea diderrichii in Wistar rats. Methods: The effect of aqueous and ethanolic extracts of Nauclea diderrichii was tested at doses of 100, 200, and 300 mg/kg on castor oil-induced secretory diarrhea, misoprostol-induced fluid accumulation, and the effect of pretreatment with yohimbine and glibenclamide. They were also tested on normal motility and castor oil- and carbachol-induced hypermotility. Results: The results showed that the aqueous and ethanolic extracts of Nauclea diderrichii significantly (p < 0.001) inhibited castor oil-induced secretory diarrhea at all the doses. Both extracts significantly (p < 0.001) inhibit fluid accumulation induced by misoprostol. The pretreatment with glibenclamide reduced the antidiarrheal activity of aqueous extract of Nauclea diderrichii. The pretreatment with yohimbine did not alter the effect of the aqueous extract of Nauclea diderrichii. On intestine transit as on castor oil- and carbachol-induced motility, the aqueous and ethanolic extracts at doses of 100 and 200 mg/kg reduced significantly (p < 0.05, p < 0.01, and p < 0.001) the travelled distance by charcoal and peristaltic index. Conclusions: The study demonstrated that the aqueous and ethanolic extracts of Nauclea diderrichii possess antisecretory and antispasmolytic properties hence its use in traditional medicine against diarrhea.
Assuntos
Misoprostol , Rubiaceae , Animais , Antidiarreicos/farmacologia , Carbacol/efeitos adversos , Óleo de Rícino/efeitos adversos , Diarreia/induzido quimicamente , Diarreia/tratamento farmacológico , Etanol , Glibureto , Parassimpatolíticos/uso terapêutico , Casca de Planta , Extratos Vegetais/uso terapêutico , Ratos , Ratos Wistar , Ioimbina/efeitos adversosRESUMO
Background: Diabetes mellitus is one of the most common chronic metabolic diseases throughout the world, characterized by hyperglycemia and insulin resistance. The purpose of this study was to evaluate the effects of aqueous extract of Emilia coccinea (AEEC) leaves on dexamethasone-induced insulin resistance in rats and on in vitro α-amylase enzyme activity. Methods: Insulin resistance was induced by intraperitoneal injection of dexamethasone (1 mg/kg) for 8 days in rats. The animals were concomitant received extracts at doses of 107.5; 215; 430 mg/kg for this period. At the end of the treatment, blood glucose level, lipid profile, transaminases, triglyceride glucose (TyG) index, body mass and relative organ weight were evaluated. Results: The results showed that AEEC inhibits α-amylase enzyme with an IC50 of 34.10 µg/ml in vitro. AEEC significantly reduced blood glucose level, triglycerides, TyG index, total and LDL cholesterol, liver weight and increased HDL cholesterol. Moreover, it reduced ALAT and ASAT activity. These parameters were strongly modify by dexamethasone. Conclusion: AEEC plays antidiabetic roles by ameliorating insulin resistance and reducing postprandial blood glucose level through α-amylase enzyme inhibition.
RESUMO
The aqueous and methanol extracts from the dry bulbils of Dioscorea bulbifera L. var sativa (Dioscoreaceae)-evaluated orally at the doses of 300 and 600 mg/kg against pain induced by acetic acid, formalin, pressure and against inflammation induced by carrageenan, histamine, serotonin and formalin in mice and rats, showed a dose dependant inhibition of pain and inflammation with a maximum effect of 56.38%, 73.06% and 42.79% produced by the aqueous extract, respectively on pain induced by acetic acid, formalin and pressure while the methanol extract at the same dose respectively inhibited these models of pain by 62.70%, 84.54% and 47.70%. The oral administration of aqueous and methanol extracts caused significant anti-inflammatory activity on paw oedema induced by histamine, serotonin and formalin. The present results show that the bulbils of Dioscorea bulbifera var sativa possess potent analgesic and anti-inflammatory activities. These activities may results from the inhibition of inflammatory mediators such as histamine, serotonin and prostaglandins. Thus, the analgesic activity of the bulbils of Dioscorea bulbifera may be at least partially linked to its anti-inflammatory activity.
RESUMO
The unique phase-sensitive acoustic microscope is used for the structural and mechanical characterization of thin films of polystyrene/polymethylmethacrylate blends. The effect of annealing on blends of polystyrene/polymethylmethacrylate spin coated from different solvents unto a substrate is studied. Varying the solvents according to vapour pressure and spin coating at different speeds (for thickness variation) led to changes in phase domain distributions and overall structural properties before annealing. Annealing in vacuum at 190 degrees C for 48 h resulted in the elimination of solvent effects with all samples reverting to a similar morphology irrespective of common solvent and thickness. The Young's moduli at specific points on the film (E(polystyrene)= 3.4 +/- 0.3 GPa, E(polymethylmethacrylate)= 4.2 +/- 0.4 GPa) and over a given area (E(polystyrene/polymethylmethacrylate)= 3.9 +/- 0.4 GPa) were determined by combinatory use of the atomic force microscope and phase-sensitive acoustic microscope. These results demonstrate a minimally invasive method for the quantitative characterization of polymer blend films.
RESUMO
AIM OF THE STUDY: The methanol/methylene chloride (CH(3)OH/CH(2)Cl(2)) extract from the stem bark of Mammea africana was showed to possess vasodilating effect in the presence and the absence of N(omega)-nitro-l-arginine methyl ester (l-NAME). The present study was designed to evaluate the effects of the methanol/methylene chloride from the stem bark of Mammea africana. MATERIALS AND METHODS: The extract (200 mg/(kg day)) was administered orally in rats treated concurrently with l-NAME (40 mg/(kg day)). l-Arginine (100 mg/(kg day)) and captopril (20 mg/(kg day))were used as positive controls. Bodyweight, systolic arterial blood pressure and heart rate were measured weekly throughout the experiment period (28 days). At the end of treatment, animals were killed and the cardiac mass index evaluated. The aorta was used to evaluate the endothelium-dependant relaxation to carbachol. The aorta contraction induced by noradrenalin was also examined and expressed as a percentage of that induced by KCl. RESULTS: The extract neither affected the body weight nor the heart rate. The extract as captopril completely prevented the development of arterial hypertension. Both the substances failed to restore the endothelium-dependent vascular relaxation and increased the vascular contraction to norepinephrine in relation to KCl contraction. They also significantly reduced the left ventricular hypertrophy induced by l-NAME. CONCLUSION: These findings are in agreement with the traditional use of Mammea africana in the treatment of arterial hypertension and indicate that it may have a beneficial effect in patients with NO deficiency but will be unable to improve their endothelium-dependent vasorelaxation.
Assuntos
Inibidores Enzimáticos , Hipertensão/tratamento farmacológico , Mammea/química , NG-Nitroarginina Metil Éster , Fitoterapia , Animais , Pressão Sanguínea/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Carbacol/farmacologia , Frequência Cardíaca/efeitos dos fármacos , Hipertensão/induzido quimicamente , Hipertensão/fisiopatologia , Masculino , Metanol , Cloreto de Metileno , Agonistas Muscarínicos/farmacologia , Músculo Liso Vascular/efeitos dos fármacos , Miocárdio/patologia , Tamanho do Órgão/efeitos dos fármacos , Casca de Planta/química , Extratos Vegetais/uso terapêutico , Caules de Planta/química , Ratos , Ratos Wistar , SolventesRESUMO
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.
Assuntos
Aorta Torácica/efeitos dos fármacos , Cumarínicos/farmacologia , Mammea/química , Casca de Planta/química , Extratos Vegetais/farmacologia , Vasodilatadores/farmacologia , Animais , Cumarínicos/química , Cumarínicos/isolamento & purificação , Inibidores Enzimáticos/farmacologia , Feminino , Cobaias , Masculino , Estrutura Molecular , NG-Nitroarginina Metil Éster/farmacologia , Caules de Planta/químicaRESUMO
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.
Assuntos
Analgésicos/uso terapêutico , Anticonvulsivantes/uso terapêutico , Kalanchoe , Fitoterapia , Extratos Vegetais/uso terapêutico , Convulsões/tratamento farmacológico , Animais , Convulsivantes/toxicidade , Feminino , Masculino , Camundongos , Pentilenotetrazol/toxicidade , Folhas de Planta/química , Ratos , Ratos Wistar , Convulsões/induzido quimicamente , Semicarbazidas/toxicidadeRESUMO
Methanol, ethylacetate and aqueous extracts of Ruellia praetermissa initiated spontaneous contractions in the quiescent and increased contraction on the electrically stimulated ileal strip at a concentration of 30 microg/ml. The extracts produced concentration-related contractions both in amplitude and tone up till 750 microg/ml with IC(50) of 360 microg/ml (methanol extract), 425 microg/ml (ethylacetate extract) and 540 microg/ml (aqueous extract). Acetylcholine also produced a concentration-related (IC(50)=18 microg/ml) contractions of the isolated ileum. Atropine in concentrations of 3.4 x 10(-6)-3 x 10(-3) microg/ml antagonized progressively the response of the isolated ileum to acetylcholine (32 x 10(-2) microg/ml) and the methanol extract (650 microg/ml) induced contractions suggesting a mode of action via cholinergic system. Luteolin and apigenin and iridoid glucosides (taxiphilin and 8-epi-deoyganic acid) might be responsible at least in part for the observed effect.
Assuntos
Catárticos/farmacologia , Plantas Medicinais/química , Animais , Camarões , Catárticos/química , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Etanol , Feminino , Cobaias , Íleo/efeitos dos fármacos , Técnicas In Vitro , Masculino , Medicinas Tradicionais Africanas , Metanol , Contração Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Solventes , ÁguaRESUMO
The effect of leaf aqueous extract of Bidens pilosa Linn. on KCl- and norepinephrine-induced contractions of rat aortic strips was studied. In aortic strips with endothelium intact, contractions induced using 60 mM KCl and 10(-5) M norepinephrine were dose-dependently relaxed by the extract, a more significant effect being seen with norepinephrine-induced contractions. Following mechanical damage to the aortic endothelium, inhibition of contractions was more prominent (105%) with the norepinephrine-induced contractions compared with KCl-induced contractions (15%) when the maximal dose (8 mg/ml) of the extract was used. The results suggest that the relaxation effect of the extract may be due to the blockade of the influx of extracellular Ca2+ into the cell.
Assuntos
Aorta/efeitos dos fármacos , Asteraceae/química , Norepinefrina/farmacologia , Extratos Vegetais/farmacologia , Folhas de Planta/química , Cloreto de Potássio/farmacologia , Animais , Aorta/fisiologia , Técnicas In Vitro , Contração Muscular/efeitos dos fármacos , Ratos , Ratos WistarRESUMO
The MeOH stem bark extract of Erythrophleum suaveolens dissolved in water and shaken up with ethylacetate (EtOAc) and fractionated on a polyamide column with methanol as eluent produced five principal fractions. These fractions were designated as fraction A (74.8 mg yield and rich in alkaloids), fraction B (36.6 mg), fraction C (7.8 mg yield, monomeric procyanidin), fraction D (26.6 mg yield, rich in monomeric and oligomeric procyanidin), and fraction E (18.1 mg yield, rich in polymeric procyanidin). The original MeOH extract administered (100 mg/kg po) produced about 47% inhibition of carrageenin-induced paw oedema 1 h after administration. Fraction D, obtained from the ethylacetate extract and rich in procyanidins produced over 33% inhibition of carrageenan-induced paw oedema while a dose of 19.2 microg/ml produced 100% inhibitory effect on 5-lipoxygenase. A dose of 100 mg/kg of the MeOH extract also produced over 30% reduction of the sensitivity to pain while 50 mg/kg of fraction D rich in procyanidins produced over 45% analgesic effects. These results were judged significant compared to those obtained with indomethacin and acetylsalicylic acid. These findings suggest that extracts of the bark of Erythrophleum suaveolens possess potent anti-inflammatory and analgesic property and that the procyanidins lead to the observable pharmacological effects.
Assuntos
Analgesia , Anti-Inflamatórios/uso terapêutico , Inibidores de Lipoxigenase , Fitoterapia , Extratos Vegetais/uso terapêutico , Animais , Anti-Inflamatórios/isolamento & purificação , Carragenina/antagonistas & inibidores , Feminino , Masculino , Extratos Vegetais/análise , Extratos Vegetais/isolamento & purificação , Ratos , Ratos WistarRESUMO
Mitragyna ciliata is widely used in traditional medicine for the treatment of inflammation, hypertension, headache, rheumatism, gonorrhoea and broncho-pulmonary diseases. In the present study, the anti-inflammatory and analgesic properties of the stem bark extract of M. ciliata were investigated. The stem bark of this plant was extracted over Soxhlet with hexane followed by another extraction with methanol. The resulting methanol extract was used for the pharmacological test. Anti-inflammatory activity was evaluated on the basis of the inhibitory effect of the extract on 5-lipoxygenase, and carrageenin-induced hind paw oedema in the rat. The methanol extract, at a dose of 19.2 microg/ml, exhibited no inhibition on 5-lipoxygenase. However, this extract administered per os (50 mg/kg) produced about 70% inhibition of carrageenin-induced paw oedema 1 h after administration. This inhibition was maintained to about 50% 2 h after administration. The dose of 50 mg/kg of MeOH extract significantly decreased sensitivity to pain from 78.75 to 107.5 g These findings suggest that extracts of the bark of M. ciliata, possess potent anti-inflammatory and analgesic effects. Chemical analysis of the extract showed the presence of alkaloids and kaempferol derivative which may be responsible for the anti-inflammatory properties.
Assuntos
Analgésicos/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Mitragyna/química , Dor/tratamento farmacológico , Fitoterapia , Casca de Planta/química , Extratos Vegetais/uso terapêutico , Caules de Planta/química , Analgésicos/química , Animais , Anti-Inflamatórios/química , Araquidonato 5-Lipoxigenase/metabolismo , Feminino , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Leucócitos/efeitos dos fármacos , Leucócitos/enzimologia , Masculino , Extratos Vegetais/química , Ratos , Ratos WistarRESUMO
OBJECTIVE: To investigate the effects of Dracaena arborea (D. arborea) on the sexual behavior parameters in experienced type-1 diabetic rats. METHODS: Aqueous and ethanol (100 and 500 mg/kg respectively) extracts of dried root barks of D. arborea, sildenafil citrate (1.44 mg/kg), trimethylamine-N-oxide (TMAO, 20 mg/kg) and distilled water (10 mL/kg) were orally administered to 4 weeks streptozotocin-induced diabetic rats. Mount latency and frequency (ML, MF), intromission latency and frequency (IL, IF) and post-ejaculatory interval (PEI) were measured by ejaculatory series during 90 min once a week for 4 weeks. Glycemia was determined at the beginning and at the end of the treatment. RESULTS: D. arborea did not show any major antihyperglycemic effects. Compared to the control group, a significant (P<0.05-0.001) increase in MF and IF was noticed in rats treated with sildenafil citrate (89.71% and 90.07% respectively), aqueous (500 mg/kg, 88.08% and 88.74% respectively) and ethanol (100 mg/kg; 89.53% and 89.17 respectively) extracts of D. arborea after two weeks (series 1) of treatment. ML, IL and PEI were significantly (P<0.05-0.001) decreased after 4 weeks of daily treatment [sildenafil citrate (96.31, 96.31% and 34.98%), and D. arborea aqueous 500 mg/kg (94.33, 94.33% and 66.60%) and ethanol extracts 100 mg/kg (96.98, 97.08% and 64.26%)]. CONCLUSIONS: These aphrodisiac potentials of D. arborea in experienced diabetic rats could be due to the antioxidant and androgenic properties of phenols, flavonoids, saponins and sterols revealed in the plant extracts.
Assuntos
Afrodisíacos/farmacologia , Diabetes Mellitus Experimental , Dracaena/química , Extratos Vegetais/farmacologia , Animais , Afrodisíacos/química , Glicemia , Ejaculação/efeitos dos fármacos , Feminino , Masculino , Piperazinas , Casca de Planta/química , Extratos Vegetais/química , Raízes de Plantas/química , Purinas , Comportamento Sexual Animal/efeitos dos fármacos , Citrato de Sildenafila , SulfonamidasRESUMO
Afrormosia laxiflora (A. laxiflora), Chenopodium ambrosioides (C. ambrosioides), Microglossa pyrifolia (M. pyrifolia) and Mimosa pudica (M. pudica) are plants used in traditional medicine in Cameroon to treat insomnia, epilepsy, anxiety, and agitation. They were evaluated for their anxiolytic like activity in mice. Animal models (elevated plus maze and stress-induced hyperthermia tests) were used. The four plants showed anxiolytic activity. In stress-induced hyperthermia test, A. laxiflora, C. ambrosioides, M. pyrifolia and M. pudica significantly antagonised the increase of temperature. ΔT° decreased from 0.75°C in the control group to 0.36°C at the dose of 110 mg/kg for A. laxiflora; from 1°C in the control group to -1.1°C at the dose of 120 mg/kg for C. ambrosioides; from 1.7°C in the control group to 0.2°C at the dose of 128 mg/kg for M. pyrifolia and from 1.3°C in the control group to 0.5°C at the dose of 180 mg/kg for M. pudica. In the elevated plus maze test, the four plants increased the number of entries into, percentage of entries into, and percentage of time in open arms. A. laxiflora, C. ambrosioides and M. pudica also reduced the percentage of entries and time in closed arms. In addition, C. ambrosioides, M. pyrifolia and M. pudica showed antipyretic activity by reducing the body temperature. The results suggested that C. ambrosioides, M. pyrifolia and M. pudica posses anxiolytic-like and antipyretic activities while A. laxiflora possesses only anxiolytic-like properties. These plants could be helpful in the treatment of anxiety and fever in traditional medicine in Cameroon.
Assuntos
Ansiolíticos/farmacologia , Ansiedade/tratamento farmacológico , Fitoterapia , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Análise de Variância , Animais , Ansiolíticos/isolamento & purificação , Comportamento Animal/efeitos dos fármacos , Temperatura Corporal/efeitos dos fármacos , Camarões , Chenopodium ambrosioides/química , Relação Dose-Resposta a Droga , Febre/tratamento farmacológico , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Medicina Tradicional , Camundongos , Mimosa/química , Atividade Motora/efeitos dos fármacos , Extratos Vegetais/uso terapêutico , Testes Psicológicos , Estresse FisiológicoAssuntos
Endotélio Vascular/fisiologia , Relaxamento Muscular/efeitos dos fármacos , Extratos Vegetais/farmacologia , Plantas Medicinais , Vasodilatadores/farmacologia , Acetilcolina/antagonistas & inibidores , Acetilcolina/farmacologia , Animais , Aorta Torácica/efeitos dos fármacos , Aorta Torácica/fisiologia , Técnicas In Vitro , Azul de Metileno , Contração Muscular/efeitos dos fármacos , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/fisiologia , Norepinefrina/farmacologia , Ratos , Ratos EndogâmicosRESUMO
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 noradrenaline 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 noradrenaline 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 alpha(1)-adrenergic pathway and calcium influx.
Assuntos
Inibidores Enzimáticos/farmacologia , Frutas/química , Hipertensão/induzido quimicamente , NG-Nitroarginina Metil Éster/farmacologia , Solanum/química , Animais , Aorta Torácica/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Carbacol/farmacologia , Feminino , Frequência Cardíaca/efeitos dos fármacos , Hipertensão/fisiopatologia , Técnicas In Vitro , Indicadores e Reagentes , Rim/efeitos dos fármacos , Masculino , Camundongos , Relaxamento Muscular/efeitos dos fármacos , Óxido Nítrico Sintase/antagonistas & inibidores , Norepinefrina/farmacologia , Tamanho do Órgão/efeitos dos fármacos , Parassimpatomiméticos/farmacologia , Extratos Vegetais/farmacologia , Extratos Vegetais/toxicidade , Ratos , Solanum/toxicidade , Vasoconstritores/farmacologiaRESUMO
The potential of phase-sensitive acoustic microscopy (PSAM) for characterizing polymer thin films is reviewed in comparison to atomic force microscopy (AFM). This comparison is based on results from three-dimensional vector contrast imaging and multimodal imaging using PSAM and AFM, respectively. The similarities and differences between the information that can be derived from the AFM topography and phase images, and the PSAM phase and amplitude micrographs are examined. In particular, the significance of the PSAM phase information for qualitative and quantitative characterization of the polymer films is examined for systems that generate surface waves, and those that do not. The relative merits, limitations and outlook of both techniques, individually, and as a complementary pair, are discussed.
RESUMO
The long-lasting antihypertensive effect of a neutral extract of Bidens pilosa has been suggested to be due to vasodilation. The present work was undertaken to assess this hypothesis. The vasorelaxant effect of a neutral extract (NBp) of the leaves of B. pilosa was evaluated in vitro on isolated rat aorta contracted with KCl or norepinephrine. NBp induced a concentration-dependent vasorelaxation of the rat aorta precontracted with KCl (60 mM) by 25%-105% at the respective concentrations of 0.25-1.5 mg/mL. The maximal concentration of 1.5 mg/mL provoked 88% relaxation of norepinephrine-induced contractions. There were no significant differences between the effects of the extract on the aorta strips with or without endothelium. In the presence of indomethacin or pyrilamine maleate, the relaxant response induced by the plant extract was significantly inhibited at the lower concentrations. The plant extract was able to reduce the aorta resting tone, inhibit the KCl-induced contractions (90% at 1.5 mg/mL) and the CaCl2-induced contractions by 95% at a concentration of 0.75 mg/mL. These results demonstrate the vasodilating properties of the neutral extract of Bidens pilosa and indicate that it may act as a calcium antagonist.
Assuntos
Bidens , Contração Muscular/efeitos dos fármacos , Músculo Liso Vascular/efeitos dos fármacos , Fitoterapia , Extratos Vegetais/farmacologia , Vasodilatadores/farmacologia , Animais , Aorta/efeitos dos fármacos , Relação Dose-Resposta a Droga , Masculino , Extratos Vegetais/administração & dosagem , Extratos Vegetais/uso terapêutico , Folhas de Planta , Cloreto de Potássio , Ratos , Ratos Wistar , Vasodilatadores/administração & dosagem , Vasodilatadores/uso terapêuticoRESUMO
Intravenous administration of 0.1-0.4 ml of a 35mg/ml stock solution of an aqueous leaf extract of Musanga cecropioides (MC) lowered the blood pressure of both normotensive and spontaneously hypertensive rats and that of the cat. (P<0.01; n=5). In indirect (tail-cuff) blood pressure trials, oral administration of 2 ml of 35 mg/ml stock solution of MC also produced a hypotensive response. The hypotensive effect was species dependent, being more pronounced in the rat and non-specific in the cat. The n-butanol extract of the original aqueous extract, consisting of mostly saponins as revealed by phytochemical studies also exhibited hypotensive effects in the rat and cat. These effects of MC were comparable with those of acetylcholine(Ach) and were antagonised by atropine (1 mg/ml).
RESUMO
The mechanisms of action involved in the hypotensive properties of the aqueous extract of the leaves of Musanga cecropioides were investigated. The effect of the aqueous leaf extract of M. cecropioides, found to contain mostly saponins, flavonoids and procyanidins, was investigated on vascular smooth muscle and also in an in vivo direct invasive blood pressure study in both normotensive and hypertensive rats. The hypotensive or antihypertensive properties of the extracts appear to be due partly to a direct or indirect vasodilator effect and also to some alpha(1)- and beta(2)-adrenergic blocking effects. The extract also exhibited significant endothelium-dependent vascular smooth muscle relaxation, accounted for by the release of nitric oxide (NO), and induced significant angiotensin converting enzyme (ACE) inhibitory effects thereby supporting its vasodilator mechanism of action.