Anti-inflammatory and antinociceptive activities of Verbascum lasianthum Boiss. ex Bentham

Abstract

Infusions of Verbascum lasianthum Boiss ex. Bentham flowers have been used for hemorrhoids in Turkish folk medicine [1]. In order to evaluate this information, MeOH and H2O extracts prepared from Verbascum lasianthum flowers were investigated for in vivo anti-inflammatory activity using carrageenan-induced hind paw edema model [2] and for antinociceptive activity using the p-benzoquinone-induced writhing model in mice [3]. The H2O extract showed a weak inhibitory effect, while the MeOH extract was significantly active (in a dose of 250mg/kg). Hence, bioassay-guided fractionation procedures were conducted with this extract. Chromatography techniques (VLC, HPLC and CC) have led to the isolation of seven iridoid glycosides as well as a saponin and their structures were elucidated by spectral techniques (NMR and MS). All isolated compounds were separately administered to the both models. Aucubin and ilwensisaponin A were found to possess significant anti-inflammatory activities, per os without inducing any apparent acute toxicity as well as gastric damage, ranging between 25.0–33.3% at 125.1mg/kg and 29.3–38.2% at 387.3mg/kg doses*, respectively. Indomethacin (36.3–45.9% at 10mg/kg*) was used as reference drug. These compounds were also found to display significant antinociceptive activity as compared to ASA. Results of the present study support the utilization of the plant in Turkish folk medicine.