title: Inhibition of COXs and 5-LOX and activation of PPARs by Australian Clematis species (Ranunculaceae).
abstract: The species of Clematis (Ranunculaceae) have been traditionally used for inflammatory conditions by indigenous Australians. We have previously reported that the ethanol extract of Clematis pickeringii inhibited COX-1. In this study, we examined the ethanol extracts and fractions of three Clematis species, Clematis pickeringii, Clematis glycinoides and Clematis microphylla, on cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX). We further examined the activating effects on the protein expression of peroxisome proliferator-activated receptor alpha (PPARalpha) and gamma (PPARgamma) in HepG2 cells. The ethanol extracts of three Clematis species inhibited the activities of COX-1, COX-2 and 5-LOX in the different extents. The stem extract of Clematis pickeringii showed the highest inhibitory activities among the three species on COX-1, COX-2 and 5-LOX with the IC(50) values of 73.5, 101.2 and 29.3 microg/mL. One of its fractions also significantly elevated PPARalpha expression by 173, 280 and 435% and PPARgamma expression by 140, 228 and 296% at 4, 8 and 16 microg/mL, respectively.
authors.affiliation: Australian Centre for Complementary Medicine Education and Research, A Joint Venture of the University of Queensland and Southern Cross University, P.O. Box 157, Lismore, NSW 2480, Australia. rachelli@hawaii.edu
authors.forename: Rachel W
authors.initials: RW
authors.lastname: Li
authors.forename: G David
authors.initials: GD
authors.lastname: Lin
authors.forename: David N
authors.initials: DN
authors.lastname: Leach
authors.forename: Peter G
authors.initials: PG
authors.lastname: Waterman
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Myers
mesh_terms: D000818:Animals; D001094:Arachidonate 5-Lipoxygenase / Q000378:metabolism; D001315:Australia; D002460:Cell Line; D039324:Clematis; D051545:Cyclooxygenase 1 / Q000378:metabolism*; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D016861:Cyclooxygenase Inhibitors / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D016859:Lipoxygenase Inhibitors; D047492:Peroxisome Proliferator-Activated Receptors / Q000378:metabolism*; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology; D018515:Plant Leaves; D018547:Plant Stems; D029626:Ranunculaceae; D012756:Sheep
chemical_list: D016861:Cyclooxygenase Inhibitors; D016859:Lipoxygenase Inhibitors; D047492:Peroxisome Proliferator-Activated Receptors; D010936:Plant Extracts; D001094:Arachidonate 5-Lipoxygenase; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2