Anti-inflammatory effects of Populus tremula, Fraxinus excelsior, Solidago virgaurea extracts and their combination Phytodolor® in human monocytes

Populus tremula, Fraxinus excelsior and Solidago virgaurea extracts are components of Phytodolor® (STW 1), a phytomedicine used in the therapy of painful inflammatory diseases especially of rheumatic origin [1,2]. Aim of this study was to analyse the effects of these components and their combination in the regulation of inflammatory processes in activated human monocytes.

Monocytes from buffy coats of healthy human donors were isolated by Histopaque-density gradient centrifugation and adhesion. The monocytes were pre-incubated for 90min with 0.05, 0.1 or 0.2% of the respective extract, Phytodolor® or 30µg/ml diclofenac. Thereafter they were incubated in serum-free RPMI 1640 medium with interferon-gamma (INF-γ; 50 U/ml; 45min) and lipopolysaccharide (LPS; 1µg/ml) for 5 to 48 hours. Apoptosis of monocytes (YO-PRO-1 staining), gene (real time PCR) and protein (Cell Elisa) expression of cyclooxygenase-2 (COX-2) and tumor necrois factor-alpha (TNF-α) were analyzed.

Populus tremula and Phytodolor® inhibited the increase of survival time of monocytes by IFN-gamma/LPS significantly and concentration dependently. The increase of pro-inflammatory gene and protein expression of COX-2 and TNF-α in activated monocytes was significantly reduced by Phytodolor® and its component extracts. Effects were comparable to diclofenac, which was used as reference.

The observed inhibition of pro-inflammatory effects by Phytodolor® and its components may be also involved in the analgetic effect of this phytomedicine. The results allow the conclusion on a supraadditive, synergistic effect of the three components.

References: [1] Klein-Galczinsky, C. (1999) Wien. Med. Wochenschr. 149: 248–253. [2] Gundermann, K.J., Müller, J. (2007) subm. for publ. in Wien. Med. Wochenschr.