Anti-Inflammatory Effects Of Herbal-Derived Factors Are Mediated By Down Regulation Of Pro-Inflammatory Cytokines

The aim of the present in vitro study is to evaluate the role of pro-inflammatory cytokines
tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6) in the observed anti-inflammatory
effects of Hypericum triquetrifolium and Peganum harmale. Therefore, water extracts from
the aerial parts of the two plants were tested for their anti-inflammatory effects in vitro using
cells from the human monocyte cell line THP-1. Anti-inflammatory effects were assessed by
measuring the levels of secretory proteins and mRNA of TNF-α and IL-6 production of LPSactivated
THP-1 cells. Cells were treated with 5μg lipopolyssacharide/ml (LPS) in the
absence and presence of increasing concentrations of plant extracts. During the entire
experimental period, we used plant extracts concentrations (up to 250μg/ml) that had no
cytotoxicity as measured in MTT assay. Hypericum triquetrifolium extracts totally reduced
the LPS induced TNF-α expression and secretion. Peganum harmale extracts inhibited the IL-
6 production in a dose dependent manner reaching the control levels of untreated cells at a
concentration of 125 μg/ml. These results demonstrate that the anti-inflammatory effects of
the two plants are mediated through the inhibition of the pro-inflammatory cytokines TNF-α
and IL-6.