Hexane fraction of adlay (Coix lachryma-jobi L.) testa ethanolic extract inhibits human uterine sarcoma cancer cells growth and chemosensitizes human uterine sarcoma cells to doxorubicin

Abstract

Background: Cancer has remained among the top ten causes of death in Taiwan since 1982. Uterine sarcoma is a rare gynecologic cancer, and chemotherapy is one type of cancer treatment. Doxorubicin (Dox) is widely used for treating several cancers, including uterine sarcoma, however, multidrug resistance (MDR) is a major clinical problem and a critical cause of treatment failure. The ethanolic extracts of adlay testa (ATE) exhibited significant anticancer activities against many cancer types.

Purpose: In this study we investigated the antitumor effects of the hexane fraction of the adlay testa ethanolic extracts (ATE-Hex) on the human uterine sarcoma cancer cell line MES-SA, as well as on the multidrug-resistant human uterine sarcoma cancer cell line MES-SA/Dx5.

Methods: The MTT assay was performed to assess the effects of the extracts of different parts of the adlay on the proliferation of human uterine sarcoma cells (MES-SA and MES-SA/Dx5) and human uterine smooth muscle cells (HUtSMCs). To determine whether ATE-Hex has a chemosensitizing effect on drug-resistant uterine sarcoma cells, the MTT assay was performed to examine the synergistic effects of ATE-Hex, the chemotherapeutic drug Dox alone, and in combination. Rhodamine accumulation was analyzed using fluorescence detection. Apoptotic cells were analyzed via flow cytometry. In addition, employing a flame ionization detector (GC/FID) gas chromatography was also developed as the analysis platform for ATE-Hex.

Results: The results demonstrated that ATE-Hex exhibited the best effects of inhibition on MES-SA and MES-SA/Dx5 cells. Co-treatment of ATE-Hex and Dox could synergistically inhibit the proliferation of cancer cells. ATE-Hex reduced the rhodamine efflux in MES-SA/Dx5 cells, indicating that ATE-Hex could reduce the expression of P-gp. In addition, our results showed that treatment with ATE-Hex alone or in combination with Dox significantly inhibited the growth of cancer cells and induced apoptosis by increasing the sub-G1 phase and poly(ADP-ribose) polymerase (PARP) being cleaved. Flow cytometry revealed that ATE-Hex induced apoptosis.

Conclusion: These results suggest that ATE-Hex can inhibit human uterine sarcoma cancer cells by inducing apoptosis and increasing the chemosensitivity of the multidrug-resistant human uterine sarcoma cancer cell MES-SA/Dx5 to Dox. Furthermore, the combination of ATE-Hex and Dox could decrease MDR and increase the synergistic effect.

Keywords: Adlay testa; Doxorubicin; HUtSMCs; MES-SA; MES-SA/Dx5; Multidrug resistance.