RESUMO
Resveratrol (RES) (trans-3, 5,-4'-trihydroxystilebene) is a multi-biofunctional compound found in a variety of plants such as grapes and mulberries. Studies of nanoencapsulated resveratrol have indicated that this compound can inhibit the growth of cancer cells and free radicals. The aim of this study was to isolate resveratrol from Vitis vinifera, develop and evaluate resveratrol nanostructured lipid carriers (NLCs) and/or resveratrol encapsulated chitosan-coated nanostructured lipid carriers (CSNLCs) using low-viscous chitosan for anticancer therapy. In addition, our study was carried out to examine the prophylactic potential of RES, NLC, and CSNLC on paraquat-induced injury in rat hepatocytes. In this study we isolated resveratrol and encapsulated NLCs in phosphate-buffered saline solution using a phase inversion method. In addition, CSNLCs were prepared by ionic gelation method of NLCs using chitosan. NLCs and CSNLCs were then characterized for their particle size, zeta potential, morphology, and entrapment efficiency. Furthermore, NLCs and CSNLCs were evaluated for their cytotoxic effect on Hep-G2, human HCT-116 (colorectal cancer cell line), lymphoblastic leukemia (1301), and human MCF-7 (Michigan Cancer Foundation-7) cells as well as their effect on caspase-3 and death receptor (DR-4). In addition, incubation of hepatocytes with paraquat resulted in increased formation of TBARS (thiobarbituric acid reactive substances) with a parallel increase in lactate dehydrogenase (LDH) leakage at 1 h after incubation. Time-dependent depletion of cellular glutathione (GSH) was observed starting 2 h after incubation with paraquat. The mean particle size of NLC and CSNLC were 67.0 and 98.41 nm, zeta potential were (-) 24.8 and (+) 31.6 mV, entrapment efficiency were 74.15% and 85.46%, respectively, with the observed shapes of nanoparticle being spherical. The treatment of Hep-G2, human HCT-116, lymphoblastic leukemia (1301), and human MCF-7 cells with NLC led to high inhibition in the cell proliferation as concluded by the low IC50 values 27.7, 17.43, 35.39, and 47.66 µg/mL, respectively, whereas CSNLC had high cytotoxic effect on Hep-G2, human HCT-116, lymphoblastic leukemia (1301), and human MCF-7 cells with low IC50 values 13.29, 10.56, 16.79 and 22.60 µg/mL, respectively. Both NLC and CSNLC possess apoptotic properties through activation of the caspase-3 and death receptor (DR-4). In addition, incubation of hepatocytes with RES, NLC, and CSNLC markedly protected against paraquat-induced formation of TBARS, increase in LDH leakage, and prevented GSH depletion. The most effective doses for ethyl acetate, ethanolic, and aqueous extracts were 7.5, 10, and 12.5 µg, respectively. The results presented here may suggest that nanoencapsulated resveratrol isolated from the stems of V. vinifera to obtain NLC and CSNLC possess anticancer and apoptotic effects on cell proliferation, and therefore, can be used as new approach of pharmaceutical drugs. In addition, the results clearly suggest that the RES, NLC, and CSNLC exerted protective effect against cytotoxicity induced by paraquat. On the contrary, the effect decreased in order of CSNLC, NLC, and RES.
