TNF and metabolic dysfunction-associated steatotic liver disease: In contrast, treatment with 1.0 g of L-tryptophan or 0.01 g of melatonin, a metabolite of tryptophan, for 6 weeks or 14 months reportedly decreased serum triglyceride levels and reduced concentrations of pro-inflammatory cytokines such as interleukin-1, -6, and tumor necrosis factor-alpha in patients with steatohepatitis or nonalcoholic fatty liver disease [24,25].