RESUMO
Herbal medicine is an ancient practice that has been gaining acceptance of the medical class through scientific studies that prove its effectiveness. However, its use should still be cautious. Medicinal plants have potential toxic effects not yet discovered, and may have unproven interactions with other medications. The use of drugs during pregnancy is still very dangerous and vigorously studied; however, there are few studies of herbal medicines in pregnant women. Existing studies prioritize on teratogenic or abortifacient effects. The aim of this study was to analyze the toxic effects of Mikania glomerata Sprengel administration, popularly known as "guaco" during the gestational period of hypertensive rats. For this experimental groups consisting of pregnant Wistar rats received treatments with guaco extract (1 to 2 mL). In order to analyze the possible toxic effects of guaco during pregnancy, weight gain of rats was assessed during pregnancy; reproductive performance of rats, morphological parameters, and fetal placental histology were compared. Although some parameters presented significant differences, we can conclude that changes prioritized by literature, such as toxicity, vasodilation and hypotension, have not been caused by guaco. The only fetal changes observed were due to the maternal hypertension. Some studies have reported vasodilator and hypotensive effects of guaco. However, only a few studies exist, and its actual effects remain unknown. Specific studies should be developed with higher doses of guaco for a definitive conclusion of its toxic and non-toxic effects.
RESUMO
Embora seja notável o avanço no uso popular de plantas com finalidade terapêutica, estudos são necessários para demonstrar seus potenciais tóxicos, já que grande parte dos usuários de fitoterápicos os considera inócuos. Durante a gestação, a maioria das alterações no feto é decorrente da exposição da mãe a agentes químicos, podendo ocorrer efeitos abortivos, teratogênicos e citotóxicos. A relevância deste trabalho se deve a escassez de estudos sobre os efeitos tóxicos do extrato de Mikania glomerata, popularmente conhecida como guaco, durante o período gestacional. Foram estudadas ratas Wistar prenhes (normotensas e espontaneamente hipertensas) sob tratamento com extrato seco de M. glomerata (2mL) e avaliada a morfologia do fígado dos fetos. Todos os grupos apresentaram fetos vivos sem alterações macroscópicas, perda pré-implantação e reabsorção fetal normal. Não houve alterações anatômicas nos fígados, apenas presença de monócitos e linfócitos nas veias-centrolobulares. Conclui-se que o extrato, na concentração e formulação estudadas, não apresentou toxicidade aos fetos.(AU)
Although remarkable advances in the use of herbal medicine were observed, studies are needed to demonstrate the toxic potential of their compounds, since most of their users consider them effective and safe. During pregnancy, most of the abnormal changes in the fetus is mainly due to the mother's exposure to chemicals, resulting in abortion or teratogenic and cytotoxic effects to the mother and neonate. The relevance of this research is due to the lack of studies on the toxic effects of Mikania glomerata. popularly known as "guaco" - extract administration during the gestational period. Experimental groups of normotensive and spontaneously hypertensive pregnant Wistar rats were studied. The animals were treated with M. glomerata extract (2 ml) and the morphology of fetal liver was evaluated to evaluate the possible toxic effects of M. glomerata to fetuses. In all groups the live fetuses were without macroscopic changes and the pre-implantation loss or normal fetal reabsorption were physiologically normal (data not shown). There were no anatomical or histological changes in the livers of fetuses studied, which showed centrilobular veins with the presence of monocytes and lymphocytes. The results lead the conclusion that M. glomerata extract, at the tested concentration, did not show toxicity to rats' fetuses.(AU)