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

Phytomedicine. 2018 Mar 15:42:226-232. doi: 10.1016/j.phymed.2018.03.047. Epub 2018 Mar 19.

Abstract

Background: Bitter melon (Momordica charantia) is a commonly used food crop for management of a variety of diseases most notably for control of diabetes, a disease associated with aberrant inflammation.

Purpose: To evaluate the anti-inflammatory property of BG-4, a novel bioactive peptide isolated from the seed of bitter melon.

Methods: Differentiated THP-1 human macrophages were pre-treated with BG-4 and stimulated with lipopolysaccharide. Pro-inflammatory cytokines IL-6 and TNF-α were measured by enzyme-linked immunosorbent assay. The mechanism of action involving activation of NF-κB and phosphorylation of ERK and STAT3 was measured by western blot and immunofluorescence. The production of intracellular reactive oxygen species was evaluated by fluorescence microscopy and fluorescence spectrophotometry.

Results: BG-4 dose dependently reduce the production of pro-inflammatory cytokines IL-6 and TNF-α. The ability of BG-4 to reduce production of cytokines are associated with reduced phosphorylation of ERK and STAT3 accompanied by reduced nuclear translocation of p65 NF-κB subunit. The mechanism of action is reduction of LPS-induced production of intracellular reactive oxygen species.

Conclusion: Our results demonstrated the ability of BG-4, a novel peptide from the seed of bitter melon, to exert anti-inflammatory action. This could explain the traditional use of bitter melon against diseases associated with aberrant and uncontrolled inflammation.

Keywords: BG-4; Bitter melon; Cytokines; Inflammation; NF-Κb; Reactive oxygen species.

MeSH terms

  • Anti-Inflammatory Agents, Non-Steroidal / chemistry
  • Anti-Inflammatory Agents, Non-Steroidal / pharmacology*
  • Cell Line
  • Dose-Response Relationship, Drug
  • Humans
  • Inflammation / chemically induced
  • Inflammation / drug therapy*
  • Inflammation / metabolism
  • Interleukin-6 / metabolism
  • Lipopolysaccharides / pharmacology
  • Macrophages / drug effects*
  • Macrophages / metabolism
  • Momordica charantia / chemistry*
  • NF-kappa B / metabolism
  • Peptides / administration & dosage
  • Peptides / chemistry
  • Peptides / pharmacology*
  • Phosphorylation
  • STAT3 Transcription Factor / metabolism
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • Anti-Inflammatory Agents, Non-Steroidal
  • IL6 protein, human
  • Interleukin-6
  • Lipopolysaccharides
  • NF-kappa B
  • Peptides
  • STAT3 Transcription Factor
  • STAT3 protein, human
  • Tumor Necrosis Factor-alpha