Nicotinamide mononucleotide alleviates ethanol-induced hepatic insulin resistance / 中国药理学通报

ABSTRACT

Aim To explore the potential protective effects of nicotinamide mononucleotide(NMN)on ethanol-induced hepatic insulin resistance. Methods Primary rat hepatocytes were divided into groups of different concentrations(0, 0.1, 0.25, 0.5, 1 mmol·L-1). The effects on cell viability of hepatocytes by different concentrations of NMN were assessed by CCK-8 method. Next, the hepatocytes were incubated with ethanol(25 mmol·L-1)to establish insulin resistance model, and incubated with different concentrations of NMN(0.1, 0.5 mmol·L-1)with or without Ex527(an inhibitor of SIRT1, 10 μmol·L-1). Glucose oxidase and anthrone methods were used to measure the glucose utilization and glycogen content respectively. Western blot was used to detect the ratios of p-PI3K/PI3K and p-Akt/Akt and the expression of SIRT1. Fluorimetric NAD+ Assay Kit was used to measure the NAD+ level in hepatocytes. Moreover, the effects of NMN on the ethanol-induced hepatic insulin resistance were explored. Results Compared with ethanol group, NMN treatment not only increased the glucose utilization and glycogen content, but also up-regulated the ratios of p-PI3K/PI3K and p-Akt/Akt at both concentrations. Meanwhile, NMN effectively recovered the NAD+ level and SIRT1 expression in hepatocytes. Furthermore, the protective effects of NMN on ethanol-induced hepatic insulin resistance was blocked by Ex527. Conclusions NMN could alleviate ethanol-induced hepatic insulin resistance by up-regulating NAD+/SIRT1 pathway and further recovering PI3K/Akt insulin signaling pathway.