Isovitexin as marker and bioactive compound in the antinociceptive activity of the Brazilian crude drug extracts of Echinodorus scaber and E. grandiflorus

Abstract Echinodorus scaber Rataj and Echinodorus grandiflorus (Cham. & Schltdl.) Micheli, Alismataceae, are popularly used to relieve inflammatory complaints and as diuretic. A study on the antinociceptive effect and selected marker compounds in eleven extracts from different locations was undertaken and their antinociceptive effect was assessed. The fingerprints were compared by HPLC-DAD and the content of vitexin, isovitexin, isoorientin and vitexin-2-O-rhamnoside were determined. All samples presented antinociceptive activity reducing the writhes by 36.4-62.5% and 47.4-79.8% at 10 and 50 mg/kg, respectively; indomethacin (5 mg/kg) reduced writhes by 82.6-90.1%. The content of the flavonoids C-glycosides, however, presented a strong variation. Isovitexin and isoorientin were found in all the samples, with content ranging from traces to 14.70 µg/mg and 2.12-84.27 µg/mg extract, respectively, while vitexin-2-O-rhamnoside occurred in quantifiable amounts only in 3 out of 11 samples ranging from 5.43 to 33.13 µg/mg extract; vitexin was not detected at all or detected in trace amounts. According to the fingerprints, the samples could be arranged in four main groups. All eleven extracts showed antinociceptive activity. Isovitexin was the only flavonoid present in all samples and can be regarded, acting in synergy with the other compounds or not, as the responsible for the antinociceptive activity. Therefore, isovitexin is a good choice as chemical marker when the antinociceptive activity of E. scaber and E. grandiflorus is investigated.

Alteraçöes no teor de matéria orgânica de solos e provável efeito no poder de proteçäo ambiental nas bordas do pantanal diante da poluiçäo por pesticidas / Alterations of the content and organic matter of soils and probable effect in the power of enviromenta protection in Pantanal bank strip in front of the pollution by pesticides

Efetuou-se estudo de alteraçöes nos teores e distribuiçäo de matéria orgânica de solos submetidos a atividades altamente dependentes de pesticidas, situados na faixa de bordadura noroestedo Pantanal, município de Cáceres, Mato Grosso(Brasil), entre 1993-97. Com base nos resultados discutiu-se o provável efeito conjugado das alteraçöes que ocorrem na matéria orgânica destes solos e o uso de pesticidas sobre o poder de proteçäo dos ambientes pantaneiro, atribuído à faixa de bordadura do Pantanal. As alteraçöes encontradas na distribuiçäo e a diminuiçäo dos teores de matéria orgânica nos solos desta faixa, em consequência do tipo de açäo antrópica praticada e em face do uso de pesticidas nas atividades implantadas evidenciaram provável perda de poder de proteçäo ambiental da faixa de bordadura do Pantanal, aumentando o risco da poluiçäo química potencial existente