TNF and metabolic dysfunction-associated steatotic liver disease: Interestingly, metformin treatment in Ob-NAFLD rats (Ob-NAFLD + M) led to a significant reduction in TNF-α mRNA levels compared to the untreated Ob-NAFLD group (Figure 6A), whereas Ccl2 and CXCR2 levels remained unchanged (Figure 6 B,C).