Figure 1. LBP activates SIRT1 deacetylase activity and protein expression by increasing the NAD⁺/NADH ratio.

(A) The effect of different concentrations of LBP on SIRT1 deacetylase activity. Data are expressed as the mean ± SEM (n = 5). ^**P < 0.01 vs. control. (B) Intracellular levels of NAD⁺ and (C) the NAD⁺/NADH ratio were measured in HepG2 cells incubated with LBP for 24 hours. Data are expressed as the mean ± SEM (n = 5). ^*P < 0.05, ^**P < 0.01 vs. control. (D,E) SIRT1 protein expression was determined by immunoblotting LBP-treated cells exposed to different concentrations or times. Data are expressed as the mean ± SEM (n = 3). ^*P < 0.05, ^**P < 0.01 ^***P < 0.001 vs. control. All data were derived from three independent experiments.