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.

Hepatoprotective effects of Turkish folk remedies on experimental liver injury.

Seven plants which are used in Turkish folk medicine were studied for possible hepatoprotective effects. These plants are Carduus acanthoides and C. nutans (Asteraceae), Cichorium intybus (Asteraceae), Fumaria asepalae and F. vailantii (Fumariaceae), Gentiana olivieri (Gentianaceae) and Plantago lanceolata (Plantaginaceae). Stems, bracts and receptaculum of Cynara scolymus were used as natural reference drugs. Effects of the ethanolic extracts were studied using the carbon tetrachloride-induced hepatotoxicity model in rats. The extracts of F. vailantii and G. olivieri significantly prevented the elevation of plasma and hepatic malondialdehyde formation (evidence of lipid peroxidation) as well as enzyme levels (AST and ALT) in acute liver injury, which might be ascribed to their potent hepatoprotective activity. Liver sections were also studied histopathologically to confirm the biochemical results.

Studies on the vascular effects of the fractions and phenolic compounds isolated from Viscum album ssp. album.

Viscum album L. has been used in the indigenous system of medicine for treatment of various diseases such as atherosclerosis and hypertension. In the literature, phenylpropan and flavonoid derivatives were suggested to play a role in the inhibition of cyclic adenosine monophosphate (cAMP)-phosphodiesterase (PDE) and a correlation was proposed between the in vitro inhibition of PDE and in vivo pharmacological activity. The vascular effects of the phenolic compounds and subfractions isolated from n-butanolic fraction of V. album ssp. album were studied on noradrenaline-contracted rat aortic rings. Isolated phenolic compounds (Syringin (VA-1), Coniferin (VA-9), 5, 7-dimethoxy-flavanone-4'-O-[beta-D-apiofuranosyl(1-->2)]-beta-D-gl uco pyranoside (VA-4)) produced concentration-dependent contractions in rat aortic rings. Only one compound (Kalopanaxin D (VA-15)) displayed very slight relaxant response. The weak concentration-dependent relaxing effect of the subfractions gave the idea that vasodilator activity were observed in the less polar subfractions. In addition, there was no clear correlation between the weak relaxant effects of subfractions and an inhibitory effect on cAMP-PDE.

A new acyclic monoterpene glucoside from Viscum album ssp. album.

2,6-Dimethylocta-2,7-diene-1,6-diol 6-O-[6'-O-beta-D-apiofuranosyl]-beta-D-glucopyranoside (1) was isolated from Viscum album ssp. album.

Pyrrolizidine alkaloids from Senecio lorenthii.

The isolation and NMR spectra of otosenine (1) and seneciphylline (2) from Senecio lorenthii are reported.