Search

Dibenzylbutyrolactone-type lignans are phenolic compounds of medical importance. The purpose of the study was to determine the effects of two such lignans, arctigenin and trachelogenin on the motility of isolated rat ileum and obtain indications on their mechanism of action. They were isolated from Arctium lappa and Cirsium arvense, respectively, which have been used traditionally to treat gastrointestinal disorders. 1–1.5 cm long segments of distal ileum were obtained from adult male Wistar rats. The intestinal segments were suspended vertically in a well-aerated organ-bath according to Magnus mounting method. The intestinal motility was monitored for 30 min before treatment to obtain the baseline, followed by treatment with 1 µM, 10 µM, 20 µM and 40 µM concentrations of arctigenin and 0.5 µM, 1 µM, 10 µM and 20 µM of trachelogenin concentrations. The amplitude, tone, and period of spontaneous contractions were measured after 15 and 30 min of treatment. To investigate their mechanism of action, cholinergic, glutamatergic, adrenergic antagonists and compounds inhibiting nitric oxide synthase and L-type calcium channels were also tested. Arctigenin and trachelogenin decreased the frequency of contractions in a dose-dependent manner. At the concentration of 20 µM and 40 µM of trachelogenin and arctigenin, respectively, there was a marked alteration in spontaneous contraction pattern with an observable increase in the period time. This activity was comparable to 0.5 µM nifedipine (L-type calcium channel blocker) treatment. Our results demonstrate relaxant effect of arctigenin and trachelogenin on the ileum motility that may be mediated by L-type calcium ion channel blockade.

Dibenzylbutyrolactone-type lignan glycosides (tracheloside and carthamoside), their aglycones (trachelogenin and carthamogenin) and feruloyl-serotonin isomers were determined in the fruits ofLeuzea carthamoidesby using LC–UV, LC–MS/MS and GC–MS techniques. The composition of the embryo and wall parts of the fruits was analysed before and after their hydrolysis. As a result of these studies, fruit part-specific accumulation of lignan glycosides and feruloyl-serotonins were confirmed, demonstrating that the embryo contains a high amount of lignan glycosides (tracheloside 32.9 mg/g, carthamoside 45.3 mg/g), while the wall part of the fruit accumulates feruloyl-serotonins (63.0 mg/g). Enzymatic hydrolysis of the embryo resulted in the quantitative transformation of lignan glycosides into their corresponding aglycones, allowing selective isolation of trachelogenin and carthamogenin. These aglycones were subjected to an antiproliferative study against the SW480 colon adenocarcinoma cell line. In this test, moderate activity of carthamogenin and a significant effect of trachelogenin were demonstrated in a concentration range of 22–185 μM. [ABSTRACT FROM PUBLISHER]

ABSTRACT Introduction Dibenzylbutyrolactone-type lignans are the physiologically active constituents of the achene fruits of Cynareae. These lignans occur in glycoside/aglycone forms: in the highest quantity of the arctiin/arctigenin, matairesinoside/matairesinol and tracheloside/trachelogenin pairs found in the fruits of Arctium lappa L., Centaurea scabiosa L. and Cirsium arvense (L.) Scop. Objective To optimise the extraction yield of the arctiin/arctigenin, matairesinoside/matairesinol and tracheloside/trachelogenin glycoside/aglycone pairs, from the fruits of Arctium lappa, Centaurea scabiosa and Cirsium arvense, under the ripening, germination and enzymatic hydrolysis processes of the fruits. Methodology Identification and quantification of lignans were performed with on-line gas chromatography-mass spectrometry (GC-MS) and with high performance liquid chromatography (HPLC), both with UV and mass selective detections (HPLC-UV/MS). Results As novelties to the field it was confirmed that: (i) the unripe fruits provide a high amount of lignans, similar to the ripe fruit; (ii) the fruits of Arctium lappa and Cirsium arvense do have glycosidase activity to hydrolyse their lignan glycosides into free lignans; (iii) the glycosidase of Centaurea scabiosa fruit becomes activated under its germination process only; and (iv) the overwhelming part of the fruits lignan contents (80-94%) in all three species are accumulated in the embryo. Conclusion The best sources of (i) lignan aglycones are the enzyme-hydrolysed embryos, separating spontaneously during the germination process, and (ii) lignan glycosides are the unripe fruits. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]