|JONES, LYNSEY - University Of Tennessee
|PANGLOLI, PHILIPUS - University Of Tennessee
|DIA, VERMONT - University Of Tennessee
Submitted to: Phytomedicine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/18/2018
Publication Date: 3/15/2018
Citation: Jones, L.D., Pangloli, P., Krishnan, H.B., Dia, V.P. 2018. BG-4, a novel bioactive peptide from momordica charantia, inhibits lipopolysaccharide-induced inflammation in THP-1 human macrophages. Phytomedicine. 42:226-232. https://doi.org/10.1016/j.phymed.2018.03.047.
Interpretive Summary: Several studies have shown a pivotal role for soybean protease inhibitors as putative anti-cancer agents. During the course of purification of soybean protease inhibitor, we also observed that seeds of bitter gourd, a perennial plant with reported health benefits, accumulate large amounts of protease inhibitors. Bitter gourd is one of the most widely used medicinal plants in managing high blood sugar in diabetic patients. The involvement of inflammation in diabetes has been known for a long time. Inflammation in diabetes have been shown to contribute to increased blood glucose concentration. Chronic systemic inflammation in patients with diabetes is a major driver of increased risk in developing cardiovascular risk. In this study, we examined the anti-inflammatory effects of bitter gourd protease inhibitor and found it very effective in suppressing inflammation. Information from this study will enable scientists to exploit protease inhibitors from plant sources such as soybean and bitter gourd for the management of inflammatory-related disorders such diabetes.
Technical 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-a were measured by enzyme-linked immunosorbent assay. The mechanism of action involving activation of NF-'B and phosphorylation of ERK and STAT3 was measured by western blot and immunofluorescence. The production of intracellular reactive oxygen species was measured by fluorescence microscopy and fluorescence spectrophotometry. Results: BG-4 dose dependently reduce the production of pro-inflammatory cytokines IL-6 and TNF-a. 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-'B 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 tradition use of bitter melon against diseases associated with aberrant and uncontrolled inflammation.