Contribuição ao estudo químico e biológico de Praxelis clematidea (Griseb.) R. M. King & H. Rob

Abstract

This study reports the chemical and biological study of the aerial parts of Praxelis clematidea. In it, the essential oil from the aerial parts of the species (OEPC) was extracted through hydrodistillation of fresh plant material. The hexane extract (EHPC) and the ethanol extract (EEPC) of P. clematidea were also obtained, separately, by cold extraction. The chemical constituents of OEPC were identified by gas chromatography coupled to mass spectrometry (GC-MS), as well by comparison with data described in the literature, and quantified by means of gas chromatography coupled to a flame ionization detector (GC - FID). A total of 24 constituents were identified, with seven of them already described in the literature for the essential oil of the aerial parts of the species. EHPC, EEPC and OEPC were bioassayed on third-stage larvae of Aedes aegypti, with only OEPC showing larvicidal activity, with a mean lethal concentration (LC50) of 82.39 ± 0.72 µg/mL. The cytotoxic activity of EHPC, EEPC and OEPC on human tumoral lineages HCT 116 (colorectal carcinoma), NCI-H1299 (non-small cell lung cancer) and K562 (chronic myeloid leukemia) was determined by the MTT method and, according to the intensity scale to evaluate the cytotoxic potential, EHPC and EEPC showed little cytotoxic activity, while OEPC showed high cytotoxic activity, with inhibition percentages of 106 ± 5.28%, 100 ± 0.14% and 98.79 ± 0, 84% for HCT116, NCI-H1299 and K562, respectively. The mean inhibitory concentration (IC50) for OEPC on the analyzed human tumoral lineages was calculated using non-linear regression in the GraphPad Prism. program, obtaining values of 10.30 µg/mL, 17.00 µg/mL and 30.07 µg/mL for HCT 116, NCI-H1299 and K562, respectively. This is the first report of the investigation of the larvicidal and cytotoxic activity of the extract in hexane, the extract in ethanol and the essential oil of the aerial parts of the species.