Beta-hydroxy-beta-methylbutyrate Inhibits Lipopolysaccharide-induced Interleukin-6 Expression by Increasing Protein Phosphatase-1α Expression

Beta-hydroxy-beta-methylbutyrate (HMB), a leucine metabolite, has been suggested to inhibit inflammation. However, its mechanism is not fully understood. Here we show that HMB repressed LPS-induced interleukin-6 (IL-6) expression by inhibiting the NF-B and AP-1 pathways. When protein phosphatase-1 (PP1) was knocked down, the effects of HMB were partly abrogated. We conclude that HMB might repress inflammation by modulating PP1 and its downstream NF-B and AP-1 pathways.