[Zinc supplementation effects on alcoholic liver disease and the molecular mechanism]

To examine dietary zinc supplementation could alleviate the damage of alcoholic liver disease and the relationship with the expression of hepatocyte nuclear factor 4alpha (HNF-4alpha).

40 adult C57 BL/6 mice were randomly divided into four groups (n = 10): control, zinc, ethanol and zinc plus ethanol, which were sacrificed after fed four different diets for 6 months. Zinc sulfate was added in the drinking water of the Zinc and Zinc Plus Ethanol group and the content was 75 mg/L. Liver regeneration was assessed by immunohistochemical staining of proliferating cell nuclear antigen (PCNA), and the expression of HNF-4alpha was determined by RT-PCR and Western blot. And as to assess the status of oxidative stress of the mice, malondialdehyde (MDA) and superoxide dismutase (SOD) were detected.

Compared with the control group, the expression level of HNF-4alpha decreased significantly in the ethanol group (P < 0.05), and the content of MDA increased significantly in this group, while the content of SOD declined significantly (P < 0.05). Compared with the ethanol group, the number of PCNA-positive hepatocytes increased significantly, and the expression level of HNF-4alpha also increased in the zinc plus ethanol group (P < 0.05), and the content of SOD increased in this group, while MDA decreased significantly (P < 0.05).

Long term ethanol exposure can lead to oxidoreduction imbalances which can be reversed by zinc supplementation. We suppose that zinc-enhanced liver regeneration is associated with an increase in HNF-4alpha, suggesting that dietary zinc supplementation may have beneficial effects in alcoholic liver disease.