RESUMO
Objetivou-se avaliar a atividade antimicrobiana do alho (Allium sativum Liliaceae), in natura, e do extrato aquoso, frente à Candida albicans (Ca) e a Estreptococos do grupo B (EGB). O alho in natura e os extratos aquosos 30% e 170%, foram submetidos à avaliação da atividade antimicrobiana usando os métodos de Difusão em Ágar pela técnica do disco e do poço. Os resultados mostraram que o alho, in natura, apresentou halo de inibição de 55,3 ± 2,6 milímetros (mm) frente a Ca e de 27,1 ± 2,6 mm frente à EGB, enquanto o halo de inibição do miconazol foi de 24 ± 0,5 mm e o da Penicilina G de 29,8 ± 0,3 mm. O extrato aquoso de alho a 30% não apresentou atividade antimicrobiana frente à Ca e à EGB Já o extrato aquoso de alho a 170% apresentou halo de inibição frente a Ca, de 11,3 ± 0,7 mm na técnica do disco e de 14,5 ± 0,9 mm na técnica do poço, porém não inibiu o crescimento da EGB Conclui-se que o alho in natura apresentou melhor efeito inibitório frente às cepas de Ca e de EGB.
This study aimed to evaluate the antimicrobial activity of fresh garlic (Liliaceae Allium sativum) and its aqueous extracts against Candida albicans (Ca) and group B Streptococcus (GBS). Fresh garlic and its aqueous extract in concentrations of 30% and 170% were evaluated for their antimicrobial activity using the agar diffusion technique. The results showed that fresh garlic showed a halo of inhibition of 55.3 ± 2.6 millimeters (mm) towards Ca and 27.1 ± 2.6 mm towards GBS while the inhibition halo of miconazole was 24 ± 0.5 mm and the inhibition halo of Penicillin G was 29.8 ± 0.3 mm. The aqueous extract of garlic in the concentration of 30% showed no antimicrobial activity towards Ca and GBS The aqueous extract of garlic at 170%, showed a halo of inhibition towards Ca, of 11.3 ± 0.7 mm in the disk technique and 14.5 ± 0.9 mm in the well technique, but did not inhibit the growth OF GBS We conclude that the fresh garlic showed a better inhibitory effect against the strains of Ca and GBS.
Assuntos
Extratos Vegetais/análise , Alho/metabolismo , Anti-Infecciosos/análise , Plantas Medicinais/classificação , Candida albicans/isolamento & purificação , Estreptococos Viridans/isolamento & purificaçãoRESUMO
To evaluate the effect of the standardized aqueous extract (AE) of Cecropia glaziovii Sneth on the plasma angiotensin I converting enzyme (ACE-EC 3.4.15.1) activity, rats were treated with a single dose of AE (1 g/kg, p.o.) or repeatedly (0.5 g/kg/bid, p.o.) for 60 days. Captopril (50 mg/kg, p.o.) was used as positive control on the same animals. The effects on the blood pressure were recorded directly from the femoral artery (single dose), or indirectly by the tail cuff method (repeated doses) in conscious rats. The plasma ACE activity was determined spectrofluorimetrically using Hypuril-Hystidine-Leucine as substrate. The arterial blood pressure, heart rate and plasma ACE activity were not significantly modified within 24 h after a single dose administration of AE. Comparatively, blood pressure in captopril treated rats was reduced by 7-16% and heart rate was increased by 10-20% from 30 min to 24 h after drug administration. ACE activity after captopril presented a dual response: an immediate inhibition peaking at 30 min and a slow reversal to 32% up-regulation after 24 h. To correlate the drug effects upon repeated administration of either compound, normotensive rats were separated in three groups: animals with high ACE (48.8+/-2.6 nmol/min/ml), intermediate ACE (39.4+/-1.4 nmol/min/ml) and low ACE (23.5+/-0.6 nmol/min/ml) activity, significantly different among them. Repeated treatment with AE reduced the mean systolic blood pressure (121.7+/-0.5 mm Hg) by 20 mm Hg after 14 days. The hypotension was reversed upon washout 60 days afterwards. Likely, repeated captopril administration decreased blood pressure by 20 mm Hg throughout treatment in all groups. After 30 days treatment with AE (0.5 g/kg/bid, p.o.) the plasma ACE activity was unchanged in any experimental group. After captopril (50 mg/kg/bid, p.o.) administration the plasma ACE activity was inhibited by 50% within 1 h treatment but it was up-regulated by 120% after 12 h in all groups. It is concluded that the hypotension produced by prolonged treatment with AE of C. glaziovii is unrelated to ACE inhibition.