Chemical constituents and in vitro anti-inflammatory activity of Cistanche violacea Desf. (Orobanchaceae) extract.

A new iridoid (1) and a new phenylethanoid glycoside (4), together with five known compounds (2, 3, 5, 6 and 7), were isolated for the first time from the ethyl acetate soluble part of the hydroalcoholic extract of the aerial parts of Cistanche violacea Desf. (Orobanchaceae), an endemic species of the North of the Sahara. The structures of these compounds have been elucidated on the basis of extensive 2D NMR spectroscopic analysis, including COSY, TOCSY, NOESY, HSQC, CIGAR-HMBC, H2BC and HSQC-TOCSY. All compounds were isolated from C. violacea for the first time. The anti-inflammatory activity of the EtOAc extract of C. violacea, was investigated by using human red blood cell (HRBC) membrane stabilization and inhibition of the albumin denaturation method. This study demonstrates, for the first time the effectiveness of C. violacea in combating inflammation, this might be believed to be influenced by the synergistic action of the above isolated compounds. The present study suggests that C. violacea would serve as a source for the discovery of novel anti-inflammatory agents.