Glycyrrhizin Induces Apoptosis In Prostate Cancer Cell lines DU‐145 and LNCaP

Abstract

Over 2 million Americans are currently living with prostate cancer. Current treatment strategies are inefficient in controlling the disease. This has made it necessary to identify newer strategies for treating prostate cancer. Use of active principles from medically important herbs has proven to be effective in treating various forms of cancers. Glycyrrhizin, a triterpene compound isolated from roots of licorice is shown to exhibit potent in vitro cytotoxic activity against several human cancer cell lines. No information is available for prostate cancer. Therefore, in this study, we evaluated the effects of glycyrrhizin on the in vitro viability of two human prostate cancer cell lines LNCaP (hormone‐dependent) and DU‐145 (hormone‐independent). Cell viability assay using MTT showed that Glycyrrhizin inhibited prostate cancer cell proliferation in a time and dose dependent manner. The decreased viability of prostate cancer cells was found to be due to cell death. Annexin‐V FITC staining and flow cytometry confirmed significant (P<0.01) numbers of prostate cancer cells were undergoing apoptosis following exposure to glycyrrhizin compared to untreated cells. Immunocytochemistry also confirmed significant Annexin‐V staining on the surface of the glycyrrhizin‐treated cancer cells. Subsequent studies showed that glycyrrhizin also inducedDNA damages in both DU145 and LNCaP cells in a time dependent manner. In addition, caspase‐3 and caspase ‐8 activities were also significantly elevated in glycyrrhizin treated prostate cancer cells compared to untreated control cells. Taken together, these studies suggest that glycyrrhizin is a potent inducer of apoptosis in prostate cancer cells as reported with other cancer cells. This study is funded by EAM.