Mechanism Of Phenylalanine Dipeptide Compounds Y101to Anti HBV

Objective: To study Phenylalanine dipetide compounds Y101(PDC Y101) effects ofanti-hepatitis B in vitro and impact on the immunological function in vivo, andinvestigate its mechanism.Methods:1. In vitro test (1) Toxical studies of Y101in2.2.15cells: After2.2.15cells were planted for48h,5different concentrations (100,75,50,25,12.5μg/mL) of Y101were added into cultured fluid for8days, and the medium wasreplaced every4days. The cytopathic effect of Y101was observed by microscope, andit’s50%toxic concentration (TC50) and the maximum nontoxic concentration (TC0) ofY101were calculated.(2) The cells and medium of three different concentration ofY101(50μg/ml,25μg/ml,12.5μg/ml), lamivdine (50μg/mL) and2.2.15cell controlgroup were collected at the4th,8thday and4thday following drug withdrawalrespectively.The contents of HBsAg and HBeAg in the medium were measured byELISA, and the levels of HBV DNA and cccDNA in2.2.15cell of every group weredetected by ordinary PCR and Quantitative real-time PCR, respectively.(3) The effectof Y101on the activity of DHBV RCs DNAP was observed with3H isotope labellingmethod in vitro.2. In vivo test (1) The effects of Y101on nonspecific immunity,humoral immunity in normal mice were observed with carbon clearance test andquantitative hemolysis test respectively.Results:1. In vitro test (1) The maximum non-toxic concentration(TC0) of Y101was50μg/ml and the50%toxic concentration concentration(TC50) was79.44μg/ml;(2) The contents of HBsAg and HBeAg in the medium of Y101(50μg/ml) group werereduced, and the inhibition ratio at the8thday were47.09%and20.98％respectively.(3) The levels of the HBV DNA and cccDNA in the cells of Y101(50μg/ml) groupwere significantly decreased and the inhibition ratio at the8thday were83.4％and75.8％respectively.(4) Y101had no effect on the activity of DHBV RCs DNAP.2. In vivo test Compared with normal group, Y101could increase the phagocyticindex (α), spleen index and thymus gland index significantly. Conclusion:(1) Y101can inhibit the secretion of HBsAg and HBeAg and theexpression of HBV DNA and cccDNA in cell line2.2.15obviously, which indicatingthat Y101has effect of anti HBV.(2) The anti HBV effect of Y101is to inhibit theexpression of cccDNA rather than the activity of HBV RCs DNAP.(3) Y101canenhance the non-specific immunity function and humoral immune function in normalrats.