The Effect of Beta-lactoglobulin Nanocapsules Containing Astaxanthin and 5-fluorouracil on the Antioxidant Enzymes Activity of Superoxide Dismutase, Catalase and Glutathione Peroxidase in HCT116 Colorectal Cancer Cell Line

Abstract

Background: The use of nanoparticle drug delivery systems to enhance the therapeutic efficacy and reduce the side effects of anticancer drugs is taken into consideration. Astaxanthin (ATX) is a natural xanthophyll carotenoid with antioxidant, anti-inflammatory, and antiapoptotic properties used to prevent and treat some cancers. Objectives: In the present study, the antioxidant effect of beta-lactoglobulin (β-LG) nanocapsules containing ATX and 5-fluorouracil (5-FU; the first-line therapy for colorectal cancer) on the antioxidant enzymes activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) in HCT116 colorectal cancer cell line was examined. Methods: In this experimental study, HCT116 cells were treated with different treatments of encapsulation of ATX in β-LG, encapsulation 5-FU in β-LG, co-encapsulation of ATX and 5-FU in β-LG, free ATX, free 5-FU, free ATX and free 5-FU, or β-LG nanocapsules without drugs for 24, 48 and 72 hours. There is a control group in which HCT116 cells were not treated with any drug. Then, 50% inhibitory concentration (IC50) and cell viability were determined using an MTT assay. The antioxidant enzyme activity of SOD, CAT, and GPX was measured by a colorimetric method in HCT116 cells. Results: Different treatments reduced the cell viability and increased apoptotic cells in a timedependent manner, which was significant for beta-lactoglobulin nanocapsules treatment (P<0.05). It means receiving more 5-FU or ATX in the encapsulated form by HCT116 cells. The antioxidant enzyme activity of SOD, CAT, and GPX in HCT116 cells treated with beta-lactoglobulin nanocapsule treatment significantly increased compared to the control group (P<0.001). Moreover, the antioxidant activity of these enzymes in different treatments containing ATX (free or encapsulation) was significantly higher than in other treatments (P<0.05). The most increase in the activity of antioxidant enzymes is recorded in the treatment of nanocapsules containing ATX and 5-FU simultaneously. Conclusion: Increased activity of antioxidant enzymes in addition to the induction of apoptosis in colorectal cancer cells by various treatments of beta-lactoglobulin nanocapsules indicates more effective drug administration in encapsulated form as well as synergistic thera[peutic effects of ATX and 5-FU. Moreover, the main increase in antioxidant enzyme activity may be related to ATX.