Effect of Lonicerae japonicae caulis extract on the growth and apoptosis of human osteosarcoma U2OS cells

Purpose: To determine the effect of Lonicerae japonicae Caulis extract (LJCE) on the proliferation, apoptosis, and cycle distribution of human osteosarcoma U2OS cells. Methods: Human osteosarcoma U2OS cells were treated with LJCE at doses of 10, 20, 30 and 40 mg/mL, with untreated U2OS cells as the control group. Cell proliferation was measured using MTT method, while flow cytometric analysis was used for determination of apoptosis and cell cycle distribution. Results: As LJCE concentration increased, the viability of U2OS cells gradually decreased, while the apoptosis rate gradually increased. The LJCE treatment had no marked effect on G1 phase cells (p > 0.05). However, the population of G2 cells in each group increased with increasing LJCE concentration, while the S phase cells in each group decreased with increasing concentration. The cells were significantly blocked in the G2 phase (p < 0.05). Conclusion: Lonicerae japonicae Caulis extract inhibits the proliferation of U2OS cells and promotes apoptosis of U2OS cells. Therefore, LJCE possesses potentials as a novel therapeutic agent for osteosarcoma.