Acetaldehyde-induced interleukin-1β and tumor necrosis factor-α production is inhibited by berberine through nuclear factor-κB signaling pathway in HepG2 cells

Abstract

Alcoholic liver disease (ALD) is one of the most common liver diseases in the world. Increased levels of proinflammatory cytokines, including interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α), have been correlated with the patients affected by ALD. However, the direct effect of alcohol in the induction of IL-1β and TNF-α has not been clarified. In this study, we demonstrated that acetaldehyde, the metabolic product of ethanol, was able to induce IL-1β and TNF-α production in HepG2 cells. Nuclear factor-κB (NF-κB), the transcription factor involved in the regulation of cytokine production, was also activated by acetaldehyde through inhibitory κB-α (IκB-α) phosphorylation and degradation. However, the NF-κB inhibitors, such as aspirin, cyclosporin A and dexamethasone, inhibited both the acetaldehyde-induced NF-κB activity and the induced cytokine production. Therefore, these data suggested that acetaldehyde stimulated IL-1β and TNF-α production via the regulation of NF-κB signaling pathway. By screening 297 controlled Chinese medicinal herbs supervised by Committee on Chinese Medicine and Pharmacy at Taiwan, we found that Coptis chinensis (Huang-Lien) and Phellodendron amurense (Huang-Po) were capable of inhibiting acetaldehyde-induced NF-κB activity. Berberine, the major ingredient of these herbs, abolished acetaldehyde-induced NF-κB activity and cytokine production in a dose-dependent manner. Moreover, its inhibitory ability was through the inhibition of induced IκB-α phosphorylation and degradation. In conclusion, we first linked the acetaldehyde-induced NF-κB activity to the induced proinflammatory cytokine production in HepG2 cells. Our findings also suggested the potential role of berberine in the treatment of ALD.