Background: There are few reports on the biological activities of 23-hydroxyursolic acid (23-HUA). The mechanism of growth-inhibition induced by 23-HUA, isolated from Cussonia bancoensis, in human cervical squamous carcinoma HeLa cells is hereby investigated.
Materials and methods: The growth-inhibitory activity was measured by MTS assay. Caspases activation and expression of apoptosis-related proteins were detected by Western blotting. Apoptotic cells were observed by morphological analysis with Hoechst 33342.
Results: 23-HUA inhibited the growth of HeLa cells in a concentration dependent manner. Proteolytically generated fragments of caspase-3, -8 and -9 were observed in HeLa cells treated with 60 microM 23-HUA. The expression of Bcl-X(L), an anti-apoptotic protein, was markedly decreased by 60 microM 23-HUA. Morphological analysis showed that apoptotic changes occurred after treatment with 60 microM 23-HUA, and the changes were inhibited by a pan-caspase inhibitor, Z-VAD-FMK.
Conclusion: These results indicate that 23-HUA causes potent growth-inhibition by the induction of apoptosis via activation of caspases in HeLa cells.