In 2019 a scientific study carried at Strathclyde Institute of Pharmacy and Biomedical Sciences of the University of Strathclyde in England studied the effect of propolis on cytokines concerning its immunomodulatory activity. The scientists investigated its ability to alter the production of tumor necrosis factor and the cytokines in macrophage cells co-stimulated with lipopolysaccharide (LPS). All the propolis extracts suppressed the tumor necrosis factor with LPS-stimulated levels. The release of these cytokines synergized by propolis samples was observed in some propolis samples collected from certain countries. The authors concluded that propolis extracts are immunomodulatory based on the observed anti-inflammatory effects through inhibition of pro-inflammatory cytokines and metabolic reprogramming of LPS activity in macrophage cells.
Reference: Alqarni, A. M., et al. (2019). Propolis exerts an anti-inflammatory effect on PMA-Differentiated THP-1 cells via inhibition of purine nucleoside phosphorylase. Metabolites, 9(4), 75.