Abstract: The effects of free and bound polyphenols from the fruit flesh, seeds and leaves of Ziziphus jujuba Mill. var. spinosa (Bunge) Hu ex H. F. Chow on phenotype transformation of human aortic smooth muscle cells (HASMC) were studied. Each plant material was crushed and extracted sequentially with ethanol followed by digestion with alkali or a mixture of methanol and acid. The content of polyphenols was determined by the Folin-Ciocalteu assay, and the contents of free and bound polyphenols in the three plant materials were compared. The effects of the polyphenols on HASMC phenotype transformation were observed by inverted microscopy and fluorescence staining. The results showed that the yields of free polyphenols and bound polyphenols extracted by acid digestion from leaves were the highest among the three materials. Moreover, the free polyphenols from leaves and the bound polyphenols from seeds obtained by acid digestion could significantly promote the phenotype transformation of HASMCs from the synthetic type (trough-shaped) to the contractile type (shuttle-shaped) in a time- and dose-dependent manner. Therefore, they have potential applications in the prevention and treatment of atherosclerosis.

Key words: Ziziphus jujuba Mill. var. spinosa (Bunge) Hu ex H. F. Chow, polyphenols, extraction, phenotype transformation