Effects of the Turkish subspecies of Viscum album on macrophage-derived cytokines.

Viscum album L. herbs are used for the treatment of various diseases. Apart from their immunostimulatory, antitumor, and hypotension inducing activities, anti-inflammatory effects has also been recorded in the literature. Since the immunostimulatory activity of mistletoe is mainly attributed to a stimulation of the mononuclear phagocytic system and to an induction of inflammation by macrophage-derived cytokines, utilization based on anti-inflammatory activity seems in contrast with its use as immunostimulant. The inhibitory effects of 80% ethanol extracts and subfractions obtained by petroleum ether, diethylether, ethylacetate and n-butanol from three Turkish subspecies of V. album L. (ssp. album, ssp. abietis, ssp. austriacum) against interleukins (IL-1alpha and IL-1beta) and tumor necrosis factor-alpha were studied. Ethanolic (80%) extracts of all three subspecies exhibited almost no significant inhibitory activity on the proinflammatory cytokines, at least in the concentrations applied in this study. In contrast, they induce a concentration dependent stimulation of these cytokines. On the other hand, moderate to weak, dose dependent inhibitory effects were observed on fractionation, which may be attributed to the existence of less polar components with anti-inflammatory activity. Based on our results, it was concluded that the utilization of ethanol extracts for anti-inflammatory purposes would not be beneficial probably due to the partial extraction of the low-molecular-weight polypeptides, i.e. viscotoxins, which induce an inflammatory response. Moreover, for anti-inflammatory effects, extracts of Viscum album ssp. austriacum may be preferred, since higher inhibitory ratios were obtained against inflammatory cytokines than with the other two subspecies.