Atividades antibacteriana contra Gardnerella vaginalis, anti-inflamatória e antiproliferativa in vitro de extratos de folhas de Gossypium barbadense L. (Malvaceae)

Abstract

Gossypium barbadense L. (Malvaceae) leaves, known as cotton, have been used for vaginal discharge treatment. Bacterial vaginosis (BV) is the major etiology. BV is a complex infection, involving a wide variety of anaerobes, being Gardnerella vaginailis the most incident. BV increases the amount of vaginal discharge, causing epithelial cells’ lysis, it can cause, also, preterm delivery (PTD) and other complications during pregnancy, as well. PTD mechanism is not totally known, but the inflammation of fetal membranes is one accepted theory. The present work evaluated 1) antimicrobial against G. vaginalis, 2) cytotoxicity against Artemia salina, 3) cell viability of health (3T3) and cancer (MCF7) cells and 4) anti-inflammatory evaluating cytokines (IL-17, TNF- e INF-) and NO activities of crude extracts and semi-purified fractions of G. barbadense leaves. Moreover, the chromatographic profile of crude extracts and semi-purified fractions were evaluated by TLC, HPLC-DAD and GC-MS. A flavonoid was isolated, being elucidated as a replaced quercetin, probably in hydroxyl group of carbon 3, by NMR 1H, COSY and HSQC. Flavonoids were abundant in polar extracts and fractions, and fatty acids and terpenoids were abundant in nonpolar ones. Polar and nonpolar compounds were observed in dichloromethane fraction (DMF) of methanol crude extract (MCE). MCE and DMF showed a expressive activity against G. vaginalis and the synergism between flavonoids and nonpolar substances appear to be crucial. MCE and DMF do not show cytotoxicity against A. salina, and with the hexane fraction (HF) and ethyl acetate fraction (EAF) of MCE showed an increase in cell viability of 3T3. Aqueous crude extract and DMF reduced the cell viability of MCF7. A most promising anti-inflammatory activity was presented by hexanic crude extract. Other crude extracts showed a less intense activity. G. barbadense leaves extracts and semi-purified fractions, chiefly MCE and DMF, presented good potential for future in vivo studies seeking the confirmation of these activities in complex biological systems.