Inhibition of Pro-Inflammatory Functions of Human Neutrophils by Constituents of Melodorum fruticosum Leaves.

ABSTRACT: In an initial screening, the dichloromethane extract from the leaves of Melodorum fruticosum showed distinct inhibitory effects on the release of interleukin-8 (IL-8) in human neutrophils. Therefore, the aim of the present study was the phytochemical and pharmacological investigation of this extract, to better understand which compounds might be responsible for the anti-inflammatory effect. Phytochemical analysis led to the isolation of 12 known compounds and two new natural products, 5-hydroxy-6-(2-hydroxybenzyl)-4',7-dimethoxyflavanone (13) and 2',4'-dihydroxy-3'-(2-hydroxybenzyl)-4,6'-dimethoxychalcone (14). The influence of the isolated compounds on the production and release of the pro-inflammatory factors IL-8, tumor necrosis factor alpha (TNF-?), reactive oxygen species (ROS), and adhesion molecules (CD62L and CD11b) in human neutrophils was evaluated. Three constituents, melodamide A, 2',4'-dihydroxy-4,6'-dimethoxychalcone, and 2',6'-dihydroxy-4'-methoxychalcone, showed significant inhibition of IL-8 release (IC₅₀ =6.6, 8.6, and 11.6??m, respectively) and TNF-? production (IC₅₀ =4.5, 13.3, and 6.2??m, respectively).

SUBMITTER: Engels NS 

PROVIDER: S-EPMC6468251 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature