Piperine from Black Pepper Decreased the Expression of Intercellular Adhesion Molecule-1 in Macrophages

Background: Macrophages are the main players involved in inflammation. Intercellular adhesion molecule-1 (ICAM-1) facilitates macrophage polarization prior to extravasation into inflamed tissue. Piperine a natural product derived from black pepper possess useful biological and pharmacological activities. In current study, the possible anti-inflammatory effect of piperine on the expression of ICAM-1 on J774.1 murine macrophage cell line was investigated.

Methods: Lipopolysaccharide (LPS)-stimulated J774.1 cells were cultured in the presence of different concentrations of piperine to examine the changes in ICAM-1 expression by real-time PCR and flow cytometry.

Results: We found that piperine decreased ICAM-1 gene expression level from 2.4 ± 0.25 RFC (relative fold change) in LPS-only treated cells to 0.85 ± 0.525 RFC at 1μg/ml (p<0.05), 0.43 ± 0.27 RFC at 10μg/ml (p<0.01), and 0.26 ± 0.25 RFC at 20μg/ml (p<0.01). In flow cytometry, piperine at all concentrations significantly decreased ICAM-1 surface expressions (P<0.05). The geometric mean fluorescence intensity (g-MFI) in LPS-only treated cells (792 ± 57.3) decreased to 482±70 gMFI at 20 µg/ml piperine.

Conclusion: According to the results of this study, by decreasing the expression of ICAM-1, piperine is suggested as a candidate to reduce inflammation and has the potential for therapeutic benefits for immune-mediated diseases.

Keywords: J774.1 cell line; Piperine; inflammation.; intercellular adhesion molecule-1; macrophage.