Chemical characterization of Copaiba essential oil and study of its cellular cytotoxicity

Abstract

Introduction: copaifera is a genus of plants that comprises several species that produce copaiba oil, which is widely used for various purposes, such as healing, anti-inflammatory, antimicrobial, wound antiseptic, anti-tumor, among other functions. There are very few chemical studies to characterize copaiba oil. Aim: To characterize 3 different species of copaiba oil Subsequently, the effects of oils were estimated on neoplastic cells in a human glioma protocol (U251). Methods: 2 methods of analysis were used for the chemical characterization, GC-MS and ESI-MS. Results: Through these analytical techniques, 20 types of components were found in the oils. Obtaining the cell viability and cytotoxicity of the oil we performed two methods, the MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) and Neutral Red (NR), both assays were quantified by spectrophotometry. Concentrations of 1 to 10-5 µg/mL were used for 3 different species of copaiba oil and doxorubicin hydrochloride was used as a positive control. The 3 different species of copaiba oil from Pernambuco (oil 1) and Manaus (oils 2 and 3) were cytotoxic in U251, the IC50 value obtained was 6.171·10-2 μg/mL, 8.344·10-2 μg/mL and 1.385·10-4 μg/mL, respectively. They also presented cytotoxic effect, with IC50, 2.4·10-1 μg/mL, 3.7·10-2 μg/mL and 4.6·10-2 µg/mL, respectively. A high correlation was evidenced between the MTT and Neutral Red studies for the three different species of copaiba oil, with α=0.05 and r values above 0.9, using the Pearson correlation coefficient. All types of resin oils positively affected cell proliferation of in vitro studies with a correspondence between concentration and effect.