Kafirin from Sorghum bicolor inhibition of inflammation in THP-1 human macrophages is associated with reduction of intracellular reactive oxygen species.

Aberrant inflammation as a result of activation of the transmembrane protein Toll-like receptor 4 belonging to pattern recognition receptor and subsequent phosphorylation of signaling proteins facilitated by reactive oxygen species has been linked to a myriad of diseases. Sorghum is a drought-resistant cereal with health promoting properties associated with its biologically active substances such as kafirin. Kafirin is an alcohol soluble protein and accounts for as much as 70% of the total proteins in sorghum. The objective was to determine the effect of kafirin on lipopolysaccharide (LPS)-induced inflammation in THP-1 human macrophages. THP-1 human monocytic leukemia cells were differentiated into macrophages by phorbol-12-myristate 13-acetate followed by treatment of LPS with or without 50 μg/mL or 100 μg/mL concentrations of kafirin. Kafirin at 100 μg/mL reduced the production of pro-inflammatory cytokines IL-1β, IL-6 and TNF-α by 28.3%, 74.0%, and 81.4%, respectively. Kafirin reduced production of intracellular reactive oxygen species is associated with reduced phosphorylation of extracellular regulated kinase1/2 and c-JUN N-terminal kinase and nuclear translocation of p65 and c-JUN transcription factors. Our results showed for the first time the anti-inflammatory property of kafirin purified from sorghum in LPS-induced THP-1 human macrophages.