ABSTRACT
We aimed to study the antinociceptive effects of myricetin 3-O-ß-galactoside (Mi), a substance isolated from the hydroalcoholic extract of Davilla elliptica. This study examined male Swiss mice, inducible nitric oxide synthase C57B16/J knockout mice (iNOS(-/-)), and their corresponding wild type (WT). Formalin and tail-flick tests were used to evaluate the nociceptive threshold, and the carrageenan-induced paw edema test was used as a model for inflammation. The following drugs were administered to investigate the involvement of the nitrergic and opioidergic systems: L-NAME, a nonspecific nitric oxide synthase (NOS) inhibitor; L-arginine (L-Arg), a precursor for the synthesis of nitric oxide (NO); D-arginine (D-Arg), an inactive isomer for the synthesis of NO; aminoguanidine (Am), an inducible nitric oxide synthase (iNOS) inhibitor; and naloxone, a nonselective antagonist of opioid receptors. The results showed that oral pretreatment with Mi caused a dose-dependent inhibition of the inflammatory phase of the formalin test and did not alter motor performance. Intraperitoneal injection of L-NAME caused a reduction in the licking time during the second phase of the formalin test. The administration of L-Arg (but not D-Arg) reversed the antinociceptive effect of L-NAME. Furthermore, pre-administration of aminoguanidine potentiated the antinociceptive effect. Mi did not cause an antinociceptive effect in iNOS knockouts and led to a reduction in the nitrite concentration in the paws of mice. Carrageenan-induced paw edema was reduced in Swiss mice and WT mice when compared to iNOS(-/-) mice. Pre-administration of naloxone (NLX) did not reverse the antinociceptive effect of Mi, excluding the opioidergic system as a mediator of the antinociceptive effect. Thus, the results suggest that the antinociceptive and anti-inflammatory effects of myricetin 3-O-ß-galactoside are related to peripheral inhibition of nitric oxide synthesis, mainly iNOS.
Subject(s)
Analgesics/metabolism , Anti-Inflammatory Agents/metabolism , Edema/drug therapy , Galactosides/chemistry , Nitric Oxide/chemistry , Plants, Medicinal/chemistry , Animals , Male , Mice , Mice, Inbred C57BL , Mice, KnockoutABSTRACT
ETHNOPHARMACOLOGICAL RELEVANCE: Davilla elliptica St.-Hil. (Dilleniaceae) is a medicinal plant traditionally used in Brazil to treat inflammatory processes, to relieve pain, as diuretic, gastro- and hepatoprotective agents. AIM OF THE STUDY: To undertake the fractionation of the ethanolic extract from Davilla elliptica leaves guided by an antinociceptive assay. MATERIALS AND METHODS: The antinociceptive activity was evaluated through the formalin test in mice. Extract fractionation was performed by percolation through silica gel and partition between immiscible solvents, followed by successive column chromatography over Sephadex LH-20 and preparative RP-HPLC. Structure elucidation of the isolated compound was accomplished by spectroscopic data. RESULTS: The EtOAc and MeOH fractions derived from the crude extract reduced significantly the licking time in the late phase of the formalin test. The bioguided fractionation of the MeOH fraction resulted in the isolation of myricetin-3-O-ß-galactopyranoside, which produced significant inhibition on nociception induced by formalin (ID50=0.26 mg/kg; p.o.). CONCLUSIONS: These results point out that myricetin-3-O-ß-galactopyranoside contributes for the antinociceptive effect of Davilla elliptica extract, a constituent considerably more potent than diclofenac, employed as reference drug.
Subject(s)
Analgesics/therapeutic use , Dilleniaceae , Flavonoids/therapeutic use , Galactosides/therapeutic use , Pain/drug therapy , Plant Extracts/therapeutic use , Analgesics/isolation & purification , Animals , Flavonoids/isolation & purification , Formaldehyde , Galactosides/isolation & purification , Male , Mice , Pain/chemically induced , Phytotherapy , Plant LeavesABSTRACT
Avaliou-se a qualidade microbiológica da água de consumo de uma IFES do Sul de Minas Gerais. Foram coletadas oito amostras, provenientes de quatro bebedouros, instalados em diferentes setores. Utilizou-se da técnica Pour Plate, com inóculo em profundidade, para a determinação de aeróbios mesófilos; empregou-se a fermentação dos tubos múltiplos para a qualificação de coliformes totais e termotolerantes. Realizou-se também a análise físico-química para o controle de qualidade da água. Somente uma amostra apresentou número elevado de aeróbios mesófilos e não se detectou a presença de coliformes em nenhuma delas. Também não foram verificadas alterações das propriedades físico-químicas e organolépticas do material ensaiado.
