BG-4, a novel bioactive peptide from Momordica charantia, inhibits lipopolysaccharide-induced inflammation in THP-1 human macrophages

Chronic inflammation has been associated with development of difference malignancies including neurodegenerative diseases and cancer. Naturally occurring compounds with anti-inflammatory effects is an attractive way to prevent diseases associated with inflammation. BG-4 is a novel peptide isolated from the seeds of bitter melon (Momordica charantia) with potent trypsin inhibitory activity. The objectives of this research is to evaluate the capability of BG-4 to inhibit lipopolysaccharide(LPS)-induced inflammation in THP-1 human macrophages. THP-1 human macrophages were pre-treated with different concentrations of BG-4 for 8 h and challenged with LPS for 16 h. The anti-inflammatory effects were evaluated by measuring the secretion of pro-inflammatory cytokines IL-1β, IL-6 and TNF-α and compared to untreated THP-1 macrophages. The mechanism of action was explored using the NF-κB signaling pathway. BG-4 pre-treatment led at 50 µg/mL reduced production of IL-1β by 65.8%, IL-6 by 88.4% and TNF-α by 50.7%. BG-4 also decreased the nuclear translocation of p65 NF-κB subunit as measured by immunofluorescence microscopy. Our data indicates the potential of BG-4 to prevent diseases associated with aberrant and uncontrolled inflammation.