Recombinant Macrophage Migration Inhibitory Factor Derived from Trichinella spiralis Suppresses Obesity by Reducing Body Fat and Inflammation

Obesity, an escalating global health crisis, is characterized by adipose tissue hypertrophy and chronic low-grade inflammation. Although anti-obesity drugs can induce weight loss, their use is limited by adverse effects, underscoring the need for safer therapeutic strategies. In this study, we generated a recombinant form of Trichinella spiralis-derived macrophage migration inhibitory factor (rTs-MIF) and investigated its anti-inflammatory and anti-obesity effects via immunometabolic regulation. Male C57BL/6 mice fed a 45% high-fat diet were orally administered rTs-MIF, and its effects were evaluated by measuring fat mass, glucose metabolism, serum cytokines, liver histology, and adipose tissue parameters. In 3T3-L1 cells, we examined the effects of rTs-MIF on adipocyte differentiation, obesity-related gene expression, and intracellular signaling pathways. Oral rTs-MIF suppressed body weight gain, reduced fat mass, improved glucose levels, and decreased the food efficiency ratio. It also lowered pro-inflammatory cytokines and increased markers associated with M2 macrophages. In 3T3-L1 cells, rTs-MIF inhibited adipocyte differentiation and reduced the expression of lipogenic transcription factors and mouse Mif while modulating AKT and p44/42 MAPK signaling. These findings identify rTs-MIF as a potential bioactive candidate that ameliorates obesity by regulating the immune–metabolic axis.