Euterpe oleracea Mart. oil inclusion complexes: encapsulation efficiency and cytotoxicity against MRC-5 cell line
Euterpe oleracea oil; inclusion complex, MRC-5, antioxidant; encapsulation efficiency.
Euterpe oleracea is a palm tree well known for its fruit, açaí. This fruit is used to produce ice cream, pulp, and even consumed with fish and tapioca in the northern region of Brazil. The Euterpe oleracea oil (OEO) can also be obtained from the fruit, which is rich in long chains of unsaturated fatty acids, with oleic acid being its major component, and some saturated fatty acids, such as palmitic acid. OEO is applied in the cosmetic and food industry, however some intrinsic characteristics of this raw material restrict its use, such as its solubility and oxidative instability. Therefore, this work aimed to produce oil inclusion complexes with β-cyclodextrin (OEO-βCD (M) and (S)) and hydroxypropyl-γ-cyclodextrin (OEO-HPγCD (M) and (S)), through the methods of kneading (M) and slurry (S), in order to improve the solubility of OEO. The encapsulation efficiency (EE) of the complexes were also determined, as well as the antioxidant activity using the DPPH assay and cytotoxicity using the Alamar Blue assay. The OEO-HPγCD (M) and OEO-βCD (M) complexes demonstrated the best EE, with 54.9 and 26.5%, respectively. In the antioxidant assay, OEO demonstrated the best activity, only 3.97% of DPPH radical inhibition, followed by the OEO-βCD (M) complex with 3.63%. In the Alamar Blue assay (MCR-5 cell line), the OEO, OEO- HPγCD (M) and OEO-βCD (S) showed cell viability varying around 80-60% at a concentration of 25 μg/mL, while OEO-HPγCD (S) showed to be more tolerable (50 μg/mL), and OEO-βCD (M) was the one with the lowest IC50 of only 25.35 μg/mL after 72h. The results obtained through this study open new pathways to better explore the mechanism of action of the complexes in inhibiting cell viability.