Prospecção da composição e citogenotoxidade de óleos essencias de Lippia L.

Abstract

Many species of the genus Lippia (Verbenaceae family) characterized by their medicinal properties. Among the chemical and pharmacological aspects investigated in Lippia, those related to its essential oils stand out. Essential oils are produced by secondary metabolism and are complex mixtures of volatile and lipophilic substances. The aim of this study was to investigate the cytogenotoxic effects of essential oils from Lippia alba (BGEN 09 acess) and Lippia origanoides ( oro, ors and orv access). Allium cepa (onion) was used as a model for cytogenotoxicity evaluating. The onion roots were exposed for 24 hours at different concentrations of essential oil (diluted in 2.5% acetone) (50, 100, 200 , 300 and 400μg/mL). As a negative control was used distilled water and 2.5% acetone. And as the positive control Methyl methane sulfonate ( 4x10- 4M ). The slides were prepared by squashing. Parameters of cell cycle and induction of chromosomal alterations were evaluated. The oils were analyzed by Gas Chromatography - Mass Spectrometry (GC -MS). The major constituents of the essential oils were citral, trans - sabinene hydrate , 1,8- cineole and carvacrol for Lippia alba , L. origanoides (oro, ors and orv accesses) respectively. In general , all oils investigated interfered in the normal dynamics of the cell cycle (interference on mitotic index or phases indices). These effects were most evident for the oil extracted from L. alba. Similarly, exposure to the essential oils showed some increase in the percentage of chromosomal alterations, as adherent chromosomes, loss of chromosomes, later segregation and bridges. Among the observed results, the involvement of aneugenic changes seems to be the most obvious effect. Possible relationships between the compounds found in oils of these species with the changes observed are discussed. This study therefore suggests the rational use of plants of the species Lippia for therapeutic purposes and shows the need for more studies on its cytogenotoxic potential.