Evaluation of the effect of PLGA-PAA nano-encapsulated Hydroxytyrosol on inhibiting the colorectal cancer cell line HT-29 and underlying mechanism of action

Introduction: Chemotherapy was known as a potential approach for colon cancer therapy. Polymer-based nanocarriers prolong the circulation time of chemotherapeutic drugs, therefore anti-tumor drugs can passively accumulate in the malignant tumor position through the improved permeability and retention effect. The aim of the present study was to investigate anticancer potency of biodegradable and pH-sensitive nano-encapsulated Hydroxytyrosol in HT-29 cancer cell line and the potential molecular mechanism of action of Hydroxytyrosol. Materials and Methods: The poly lactide-co-glycolide-co-polyacrylic acid (PLGA-co-PAA) nano-encapsulated Hydroxytyrosol was synthesized, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was performed to evaluate the anti-proliferative and anti-tumor effects of both free and nano-encapsulated Hydroxytyrosol. The relative expression of colorectal cancer associated-1 (COCA1) gene was investigated by quantitative Real-Time PCR (qRT-PCR). Results: We observed that free and nano-encapsulated Hydroxytyrosol significantly decreased the viability of HT-29 cancer cells. Moreover, the cytotoxic effect of nano-encapsulated Hydroxytyrosol on HT-29 cancer cells was significantly more than that of free Hydroxytyrosol. Also, the COLCA1 gene expression was up-regulated significantly in HT-29 cancer cells treated with either free or nano-encapsulated Hydroxytyrosol. Conclusion: Generally, we showed that the anticancer potency of Hydroxytyrosol was significantly increased by a biodegradable and pH-sensitive nanoparticle. However, further studies on animal models seem necessary.