Butyrate protects liver against ischemia reperfusion injury by inhibiting nuclear factor kappa B activation in Kupffer cells.

BACKGROUND: The inflammatory response after hepatic ischemia reperfusion (I/R) contributes to liver dysfunction and failure after transplantation. Butyrate is a four-carbon fatty acid, normally produced by bacterial fermentation of fiber in mammalian intestines, with anti-inflammatory activities. The purpose of the present study was to investigate the protective effect of butyrate preconditioning, if any, against hepatic I/R injury in rats and the underlying mechanisms involved.

METHODS: Male Sprague-Dawley rats were subjected to a partial (70%) hepatic ischemia for 60 min after pretreatment with either vehicle or butyrate, followed by 3, 6, and 24 h of reperfusion. Hepatic injury was evaluated by biochemical and histopathologic examinations. Neutrophil infiltration was measured by myeloperoxidase (MPO) activity. The expression of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) was measured by enzyme-linked immunosorbent assay (Elisa) and Real-time reverse-transcriptase polymerase chain reaction (RT-PCR). The expression of nuclear factor kappa B (NF-κB) p65 was determined by immunohistochemistry and Western blot analysis.

RESULTS: Butyrate treatment markedly improved hepatic function and histology, as indicated by reduced transaminase levels and ameliorated tissue pathologic changes. The expression of tumor necrosis factor-alpha, interleukin-6, and myeloperoxidase activity was attenuated by butyrate. Butyrate also reduced I/R-induced nuclear translocation of NF-κB p65 in Kupffer cells.

CONCLUSION: Our results suggest that butyrate alleviates I/R-induced liver injury, possibly by suppressing inflammatory factors production and preventing NF-κB activation in Kupffer cells.