Morfoanatomia, composição química e atividades biológicas do óleo essencial de Eucalyptus tereticornis Sm.

Abstract

This study aims to investigate the morphoanatomy, chemical composition and biological activities of the essential oil of Eucalyptus tereticornis. Therefore, the morphoanatomy of the adult leaves of E. tereticornis was evaluated, and after the extraction of the essential oil from the leaves of E. tereticornis, its content and chemical profile were determined and some biological activities were verified, such as antimicrobial, antioxidant, anti-inflammatory activity. -inflammatory through the ear edema model, cell migration through histological analysis, cytotoxic activity and repellent action. In the present study, a comprehensive explanation of the leaf and stem anatomy and histochemistry of Eucalyptus tereticornis is presented. The presence of crusts such as epicuticular waxes on the leaf surfaces was observed, crystals were found in some epidermal cells as an aggregate of plaques, presence of prismatic crystals in various tissues and homogeneous mesophyll. Histochemical analyzes confirmed the presence of lipophilic and phenolic compounds, starch grains and lignified elements. The chemical composition of the essential oil by GC-MS analysis detected 25 compounds, the main components being p-cymene (46.57%), kryptone (25.24%) and terpinen-4-ol (5.23 %). In the analysis of antimicrobial activity, there was inhibition of the growth of all microorganisms tested in the disc diffusion methodology, with more satisfactory results against C. albicans and S. epidermidis; in the broth macrodilution methodology, with the exception of P. aeruginosa, bactericidal activity of the essential oil was also observed against all other strains tested. The essential oil of E. tereticornis showed an antioxidant effect by the DPPH free radical reduction method. E. tereticornis essential oil showed antiinflammatory activity when used topically, as it significantly reduced edema, tissue weight and migration of inflammatory cells. In the evaluation of the cytotoxic activity, through the reduction of MTT using the murine fibroblast (non-tumor line - 3T3) and murine melanoma (tumor line - B16F10) strains, it was observed that it is necessary to use a higher concentration of the oil to cause cytotoxicity for the tumor lineage in relation to the nontumor. In the evaluation of the repellent activity, an effect was also observed with the oil without dilution. These results show details of the morphoanatomy and histology of the plant not yet studied. New studies involving anatomical and phylogenetic analyzes of other eucalyptus species are essential to better understand the evolution and taxonomy of the genus. The present work also shows the need for continuity in studies to confirm and elucidate the mechanism of action of these and many other biological activities that may be present in the essential oil of E. tereticornis.