Evaluation of the Effects of Some Brazilian Medicinal Plants on the Production of TNF-αand CCL2 by THP-1 Cells
Several plant species are traditionally used in Brazil to treat various inflammatory diseases. Tumor necrosis factor- (TNF-)αand chemokine (C-C motif) ligand 2 (CCL2) are key inflammatory mediators in diseases like rheumatoid arthritis and atherosclerosis, respectively; nevertheless, only a few extracts have been assayed against these targets. We herein report the effect of 19 plant extracts on TNF-αand CCL2 release by lipopolysaccharide- (LPS-) stimulated THP-1 cells, a human monocytic leukemia cell line, along with their radical scavenging activity on DPPH. The extracts ofCaryocar brasiliense,Casearia sylvestris,Coccoloba cereifera, andTerminalia glabrescensinhibited TNF-αproduction in a concentration-dependent manner. Fractionation of these extracts potentiated the anti-TNF-αeffect, which was shown to concentrate in polar fractions, mainly composed by polyphenols. Significant CCL2 inhibition was elicited byLippia sidoidesandTerminalia glabrescensextracts, whose fractionation resulted in highly active low polar fractions. All assayed extracts showed strong radical scavenging activity, but antioxidant activity did not correlate with inhibition of TNF-αor CCL2 production. Our results allowed identifying extracts with selective capacity to block cytokine production; therefore, further purification of these extracts may yield molecules that could be useful in the treatment of chronic inflammatory diseases.