Hypericum triquetrifolium Extracts Modulate IL-6, IL-10 and TNF-α Protein and mRNA Expression in LPS-Activated Human Peripheral Blood Mononuclear Cells and THP-1-Derived Macrophages

The aim of the present in vitro study was carried out to evaluate the anti-inflammatory activity of Hypericum triquetrifolium extracts (HT-extract) on lipopolyssacharide -stimulated human monocytic (THP-1) cells and human peripheral blood mononuclear cells (PBMNCs). The expression and production of pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6), as well as the anti-inflammatory cytokine interleukin 10 (IL-10) were evaluated by assessing the levels of proteins and mRNA’s of TNF-α, IL-6 and IL-10 in both cell types. Cells were exposed to 5 µg lipopolyssacharide (LPS) /ml in the absence and presence of increasing concentrations of 50% ethanol extracts from the aerial parts of Hypericum triquetrifolium. The anti-inflammatory effcacy experiments were performed with HT-extract concentrations up to 250 µg/ml that had no cytotoxic effects as assessed with MTT and LDH assays. HT-extract remarkably inhibited the expression and secretion of TNF-α and IL-6 at a concentration of 250 µg/ml. HT-extract remarkably elevated IL-10 secretion and mRNA levels at 125 µg/ml. Furthermore, HT-extract exhibited relatively high antioxidant activity (IC50 of 5 µg/ml) as measured with DPPH assay. These fndings indicate that HT-extract probably exerts anti-inflammatory effects at both protein and gene expression levels of the anti-inflammatory as well of the pro-inflammatory cytokines in PBMNCs.