IN-VITRO ANTICOMPLEMENTARY ACTIVITY OF CONSTITUENTS FROM MORINDA MORINDOIDES

In a screening program for complement classical pathway modulation, an 80% MeOH extract of the leaves of Morinda morindoides showed potent d ose-dependent anticomplementary activity. Bioassay-guided chromatograp hic separation of the active constituents led to the isolation often f lavonoids of which two were aglycones. The compounds were tested in vi tro for their putative complement-inhibiting properties on the classic al (CP) and the alternative (AP) pathways of the complement system. Th e results indicated that quercetin [1], quercetin 3-O-rhamnoside (quer citrin) [5], and quercetin 3-O-rutinoside (rutin) [7] showed similar a nticomplementary activities (inhibition) on the CP of complement. A mi xture of two kaempferol triglycosides isolated and denoted as M(015), also had a good inhibitory effect. The effects of these compounds were dose-dependent for this pathway. On the AP of complement, quercetin [ 1] and M(015) had, respectively, more pronounced inhibitory and activa tory effects than the other tested flavonoids, but their effects were nor dose-dependent for this pathway. The other isolated flavonoids sho wed weak effects or were inactive for both pathways.