Synthesis of 8-bromo-ethoxy Rhein and evaluation of its inhibition effect on hepatitis B virus in human hepatoma cells HepG2.2.15 / 中国药理学通报

ABSTRACT

Aim To synthesize 8-bromo-ethoxy Rhein and investigate its mechanisms and inhibition effect on hepatitis B surface antigen ( HBsAg ) and e antigen ( HBeAg) in HepG2.2.15 cells.Methods 8-bromo-ethoxy Rhein was synthesized based on the chemical structure of Rhein , and its structure was identified by IR,1 H-NMR and 13 C-NMR spectra.MTT assay was used to test the inhibitory effect of 8-bromo-ethoxy Rhein on HepG2.2.15 cells.After the cells treatment by 8-bromo-ethoxy Rhein , the HBsAg and HBeAg in cell supernatant were detected by ELISA .The expres-sion of hepatitis B virus X gene ( HBx) was detected by Western blot .The cell cycles were examined with flow cytometry.The intracellular free calcium concentration was detected by laser scanning confocal microscopy . Results The structure of 8-bromo-ethoxy Rhein was confirmed by IR,1 H-NMR and 13 C-NMR.MTT results showed that synthetic product and Rhein could inhibit the cell proliferation in HepG2.2.15 cells.After trea-ted with 8-bromo-ethoxy Rhein and Rhein for 72 h,the half inhibitory concentration 50%( IC50 ) was 14.29 mg? L-1 and 11.59 mg? L-1 , respectively .Using non-cytotoxic dose of 8-bromo-ethoxy Rhein , the inhibitory effect on HBsAg and HBeAg was gradually enhanced with increasing 8-bromo-ethoxy Rhein concentration . The inhibitory effect of synthetic product on hepatitis B virus was better than that of Rhein .8-bromo-ethoxy Rhein could down-regulate the expression of HBx , in-tracellular calcium ion concentration and block the hepatitis B virus ( HBV ) replication.Flow cytometry results showed 8-bromo-ethoxy Rhein didn′t affect the cell cycle .Conclusions Compare with Rhein , the synthesis of 8-bromo-ethoxy Rhein shows stronger inhi-bition on hepatitis B virus in HepG2.2.15, and its mechanisms may involve down-regulating the expres-sion of HBx and reducing calcium ion concentration .