Flavonoid glycoside compounds from roots of Arctium lappa and structure-activity relationship of anti-oxidantion / 中草药

Objective: To investigate the flavonoid glycoside compounds from the roots of Arctium lappa and their structure-activity relationship (SAR) of anti-oxidantion. Methods: The compounds were isolated by column chromatography over silica gel, RP-C18, Sephadex LH-20, and PHPLC. Their structures were elucidated by spectroscopic analysis and their anti-oxidant activities were evaluated by DPPH, ABTS, and FRAP assays. Results: Eight flavonoid glycoside compounds were isolated from 55% ethanol extract in the roots of A. lappa, which were identified as nairutin (1), hesperidin (2), icariin (3), ononin (4), isoononin (5), neoliquiritin (6), neoisoliquiritin (7), and liquiritin (8). The anti-oxidant activities of these compounds were tested by three different methods (DPPH, ABTS, and FPAR), and their SAR were further analyzed. Conclusion: Compound 3 is isolated from the roots of A. lappa for the first time, all others were from the plants of Arctium L. for the first time; Compounds 1 and 8 have shown the strongest anti-oxidant activity; The -OH on C-3' and -OCH3 on C-4' in the B ring in regard to the anti-oxidant activity of these compounds by participating in electron delocalization and hydrogen bonding.

Effect of aqueous extract from roots of Arctium lappa on vascular remolding in hypertensive rats / 中草药

Objective: To observe the effect of aqueous extract from roots of Arctium lappa (AERAL) on vascular remolding in hypertensive rats. Methods: The hypertensive rat model was induced by N-nitro-L-arginine from 50 female Wistar rats, and randomly divided into model control group, positive control group (15 mg/kg), low-, mid-, and high-dose AERAL (0.5, 1.0, and 2.0 g/kg), groups. After six weeks of continuous gavage administration, rat tail artery systolic pressure, angiotensin II (Ang-II), endothelin-1 (ET-1), tumor necrosis factor-α (TNF-α), left ventricular mass index (LVWI), and thickness of thoracic aortic tunica media (TTATM) were detected. Results: Compared with the normal control group, Ang-II, ET-1, TNF-α, LVWI, and TTATM were increased and rat tail artery systolic pressure was elevated in the model control group, with significant differences between the two groups (P < 0.05); Compared with the model control group, rat tail artery systolic pressure in each treatment groups declined, serum Ang-II, ET-1, TNF-α, LVWI, and TTATM were all lowered, showing significant differences among them (P < 0.05). Conclusion: AERAL can significantly improve vascular remolding in rats with hypertension.