Óleos essenciais de Cantinoa carpinifolia (Benth.) e Lippia origanoides Kunth.: composição química, atividade antioxidante e potencial farmacológico

Abstract

The aim of this study was to evaluate the influence of the year of collection (2014 and 2015) on the chemical compositions and the pharmacological potentials of the essential oils from Cantinoa carpinifolia. and Lippia origanoides through hemolysis assays, their effects on the activities of phospholipase A2and serine proteases from snake venoms and on coagulation and dissolution of blood clots. The objective was also to investigate the antioxidant potential of the essential oils using different methods. The essential oils were obtained by hydrodistillation using a modified Clevenger apparatus, and the constituents were identified and quantifiedby GC-MS and GC-FID. The phospholipase and hemolytic activities were determined by agar diffusion using egg yolk (phospholipids) and human blood erythrocytes, respectively. BAPNA was used to determine the serine protease activity. Coagulation induced by venoms was verified using human citrated plasma, and the thrombolytic activity was measured by the volume of liquid released by thrombi. The antioxidant activity was evaluated by the methods involving stabilization of the ABTS, DPPH and hydroxyl radicals, complexation by fosfomolibdênio, reducing power, oxidation of the β-carotene/linoleic acid system and species that react with thiobarbituric acid (TBARS). The essential oilyields from C. carpinifolia were 0.48% and 0.31% in 2014 and 2015, respectively. The major constituents of the essential oil were α-thujone (32.15 and 29.21%), β-thujone (22.22 and 35,88%), β-caryophyllene (8.74 and 5.28%) and sabinene (6.65 and 5.61%) in 2014 and 2015, respectively. Carvacrol (41.51%), p-cymene (18.59%), γ-terpinene (17.03%) and thymol (4.86%) were found in the L. origanoides oil. The antioxidant activity of the essential oils varied with the method employed, and BHT, ascorbic acid and the oil from L. origanoideswere the most efficient. In the hydroxyl method, the oils were more effective than mannitol. Regarding the pharmacological characterization of the essential oils, an inhibitory action against phospholipase A2induced by the venoms of Bothrops atrox, B. jararaca, B. jararacussu and B. moojen was observed. No cytotoxicity against human blood erythrocytes was observed with all the volumes of the oil from C. carpinifolia tested. No cytotoxicity was observed with 0.6 and 1.2 μL of the essential oil from L. origanoides. However, prior incubations of the oils with venoms of B. jararacussu, B. moojeniand Crotalus durissus terrificus(C.d.t.), caused potentiation of the hemolytic activity. From the results obtained in the coagulation tests, it is inferred that the constituents of the essential oils interacted with serum components, whereas preincubation of the plasma with the oil significantly reduced the clotting time. Volumes of 0.6 and 1.2 μL of essential oil, pre-incubated with B. jararacussu venom, potentiated the action of proteases and phospholipase A2, resulting in greater dissolution of thrombi. But when the essential oil from L. origanoideswas pre-incubated with the venom of C.d.t., a thrombotic effect was induced. Essential oils provided an increase in the degradation of BAPNA induced by venoms of B. jararacaand Lachesis muta. The results improved the pharmacological characterization of these essential oils, underscoring their potential for use in drug-cosmetic industries.