Effects of chrysin on hypoxia-induced G2/M cell cycle arrest in PASMCs. (A–G) Cell cycle distribution was monitored by flow cytometry using a propidium iodide staining assay for the following groups: (A) Normoxia; (B) Hypoxia; (C) + DMSO; (D) + DPI (25 μM); (E)–(G) PASMCs pretreated with chrysin (1, 10, and 100 μM) before hypoxia treatment, respectively. (H) Percentages of cells in S + G2 phase. Data are means ± SD from three independent experiments. Statistical analysis was performed with one-way ANOVA followed by the Newman–Student–Keuls test for multiple comparisons.DPI: diphenyleneiodonium chloride.