Suppression of cervical cancer cell survival by ursolic acid extracted from Catalpa bungei leaves

Background: Previous phytochemical studies showed that extracts from leaves and seed oil of Catalpa plants showed antioxidant and antitumor activities. However, the active components and their roles and molecular mechanisms were still incompletely identified. Objective: We aimed to extract and identify the active fraction from Catalpa bungei leaves and investigate its underlying mechanism in suppressing cervical cancer cell survival. Materials and Methods: Extracts from C. bungei leaves with 80% methanol were separated into different fractions. The component with optimal inhibitory effect on HeLa cell growth was isolated, identified, and examined. Results: Extracts from C. bungei leaves with methanol were separated into petroleum ether, ethyl acetate (EA), n-butanol, and water fractions. The chemicals in EA fraction exhibited optimal inhibition effects, which were further separated into 29 fractions by the silica column chromatography. The compound with optimal antitumor activity was eventually determined to be ursolic acid (UA) based on the results of Sephadex column chromatography and1H nuclear magnetic resonance analysis. UA at 5.0 and 10.0 μg/mL substantially inhibited the growth and migration of HeLa cells. UA also retarded cell cycle at G0/G1 stage and promoted cell apoptosis through activating death receptor and mitochondria-associated pathways. Conclusion: UA isolated from C. bungei leaves could inhibit growth and migration and induce apoptosis in HeLa cells.