A medium-chain fatty acid analogue prevents endotoxin liver injury in a murine model.

Parenteral nutrition (PN) is lifesaving for patients with short bowel syndrome and other gastrointestinal disorders, however long-term use may lead to complications including hepatosteatosis and sepsis. We have previously demonstrated the anti-steatotic, -fibrotic, and -inflammatory properties of SEFA-6179, an engineered medium-chain fatty acid analogue. We hypothesized that SEFA-6179 treatment would protect against endotoxin-induced liver injury in a murine model of PN-induced hepatosteatosis. C57Bl/6J mice were administered a high-carbohydrate liquid diet plus intravenous lipid emulsion (Intralipid, 4 g fat/kg/d) or intravenous saline for 19 days to induce hepatosteatosis. SEFA-6179 (100 mg/kg) or vehicle (MCT/medium-chain triglyceride) was administered via oral gavage for four days leading up to intraperitoneal challenge with lipopolysaccharide (15 mg/kg) or saline on day 19. Age-matched, chow-fed controls received the same treatments. The primary outcome was liver biomarkers: alanine aminotransferase and aspartate aminotransferase. Pro-inflammatory cytokines, IL-6, TNF-alpha, and monocyte chemoattractant protein (MCP1), were analyzed. Liver immunofluorescence staining was performed to evaluate macrophage phenotypes. In endotoxin-challenged mice, pre-treatment with SEFA-6179 lowered liver enzymes and pro-inflammatory cytokine levels compared to vehicle. On liver histology, SEFA-6179 pre-treatment led to greater polarization of M1/pro-inflammatory macrophages to an M2/anti-inflammatory phenotype compared to vehicle. SEFA-6179 is currently in Phase II clinical trials. These findings support the potential application of SEFA-6179 in high-risk, PN-dependent patients.