Nanoemulsões à base de óleo-resina de copaíba como carreador de ácido betulínico: uma proposta para tratamento de câncer

Abstract

Drug carrier strategies or pharmacologically active agents have been widely studied in recent years. Oil-in-water (O/W) nanoemulsions are attractive drug delivery systems for hydrophobic actives. Copaiba oil, an oil-resin made up of terpenes, is used in traditional medicine as an anti-inflammatory agent and is a strong candidate to compose the dispersed phase of O/W nanoemulsions. As cancer was considered, in 2018, the second leading cause of death in the world, the interest in optimizing the efficiency and release of a hydrophobic anticancer active, such as betulinic acid, was awakened in order to reduce impacts caused by conventional treatments. The present work aims to prepare O/W nanoemulsions containing copaiba oil and betulinic acid stabilized with Pluronic® F127 and perform the characterization regarding shape and stability and its cytotoxic potential in cancer cells. The nanoemulsions showed particle size values between 284.4 nm and 308.8 nm, unimodal size distribution (PDI values between 0.023 and 0.119) and zeta potential between -21.8 and -27.1 mV. All emulsions were stable for up to 360 days. All nanoemulsions with betulinic acid were able to solubilize the active (12 to 14 mg mL-1). The presence of betulinic acid in the nanoemulsions preserved the shape of the nanodrop in the TEM images, but did not significantly influence the cytotoxic activity against cell lines of some types of cancer (prostate, lung carcinoma, leukemia, colorectal and nervous system). Nanoemulsified copaiba oil, especially copaiba oil with a majority composition of polyaltic acid and β-bisabolene, proved to be efficient and selective against the leukemia cell lineage (HL-60).