Ethanolic Extract of Hedyotis corymbosa and Its Combination with 5-FU Inhibit Cyclin D Expression on WiDr Colorectal Cancer Cell

Abstract

Hedyotis corymbosa has been used for long time as an important component in several folklore medicine formula to clinically treat various types of cancer, including colorectal cancer (CRC). Previously, Hedyotis corymbosa ethanolic extract (HEE) which contain ursolic acid reported to inhibit CRC growth via induction of cancer cell apop­tosis and blocked the cell cycle, preventing G1 to S progression where cyclin D highly espressed in this phase. 5-fluorouracil (5FU), the first line chemotherapy of colorectal cancer have had resistence and possessed several side effects such as neutropenia, immunosuppression, diarrhea, and also constipation. Therefore, the aim of this research is to conduct the antiproliferative effect and molecular analysis of HEE and its combination with 5FU. Molecular docking study was also done to approach the specific protein target of the compound. Antiproliferative effect was conducted by MTT assay, while cyclin D expression  was examined by immunofluorescence. The proliferative effect showed that both HEE and 5-FU had cytotoxic effect with IC₅₀ value of 65 µg/mL and 90 µM respectively, meanwhile the combination of HEE and 5FU have synergism effect with CI = 0.48 on dose HEE = 22 µg/mL and 5FU= 6.25 µM. Immunofluorescence assay showed HEE and its combination with 5FU suppressed the expression of cyclin D. From molecular docking simulation, ursolic acid performed stable interaction with cyclin D. Our findings suggest that HEE may be an effective treat­ment for co-chemotherapic for 5-FU through inhibition of cyclin D expression.

Keywords : Hedyotis corymbosa, 5-fluorouracil, colorectal cancer,  WiDr, cyclin D