Avaliação farmacológica de extratos e sustâncias obtidas de Plinia glomerata (berg.) / Pharmacological studies of extracts and compounds from Plinia glomerata (Berg.)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

Plinia glomerata Berg. (Myrtaceae) is popularly known as cabeludinha. The plant has several synonyms, including Myrciaria glomerata Berg., Eugenia cabelluda Kiaersk, and Eugenia tomentosa Berg. In a bibliographical review of synonyms of the plant, no pharmacological and/or phytochemical studies were found. The plant cabeludinha is acknowledged for its therapeutical uses in popular medicine, and it also belongs to a botanical family with species which are widely used as medicinal plants. In this work, pharmacological screening was carried out for extracts of Plinia glomerata Berg, to search for different pharmaceutical properties in vivo, in mice. For this, analgesia models were carried out (nocioception induced by acetic acid, formalin, capsaicin, glutamate and heat) and inflammation (ear edema induced by croton oil) and models of central action (Open Field, antagonism of convulsions induced by pentilneotetrazol and strychnine, elevated cross maze, sleep induction by Phenobarbital and the forced swimming test). When administrated peritoneally and orally, the crude methanol extract (CME), crude acetonic extract (CAE), and two isolated phenol compounds, acid 3,4,3-trimetoxi-flavelagic (CP1) and acid 3,4,3- trimetoxi-flavelagic-4-O-glicosideo (CP2), all the assays where successful and produced significant results in the formalin, capsaicin, and acetic acid models. The CME caused a dose-dependant reduction in abdominal writhing, with maximum inhibition (MI) of 70.25% at a dose of 10 mg/kg, i.p.; The CAE inhibited 64.55% at a dose of 30mg/kg, i.p. In the same model, both extracts were active when tested orally, producing statistically significant and dose-dependant results. In the formalin model, the two extracts reduced the response by 17.75% and 45.6% in the first phase (Neurogenic) and by 92.96% and 99.81% in the second phase (inflammatory), respectively. In the hot plate test and capsaicin assays, the antincioceptive effect was both effective. For the latter, MIs of 54.44 and 66.41%, respectively, were calculated for the CME and CAE. For the ear edema induced by croton oil, doses of 30 mg/Kg for both extracts inhibited the edema more effectively than the Indomethacin. Assays with CP1 and CP2 compounds at a dose of 10 mg/kg were effective in the abdominal writing test, with calculated MIs of 97.6 and 94.3 %. A similar profile was observed in the formalin test, where both extracts reduced the nocioceptive response, with MIs of 67 and 60.7% in the first phase and 37 and 53.4% in the second phase. For the capsaicin test, the compounds reduced pain, with MIs of 40.3 and 37.9%, respectively. In the pharmacological models for central action, a significant hypnotic and antidepressive effect was observed in the sleep induction test, for the extracts tested. The results, taken together, do not enable us to conclude that the plant studied exhibits pharmacological properties. Extracts CME and CAE and the compounds CP1a and CP2 demonstrated proven antinociceptive activity, while extracts CME and CAE showed antiedematogenic, hypnotic and antidepressive effects

ASSUNTO(S)

extrato metanólico bruto plinia glomerata extrato acetônico plinia glomerata nociception farmacia crude methanol extract atividade farmacológica pharmacological activity nocicepção acetonic extract

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