Abstract
Loranthus regularis Steud. ex Sprague (Loranthaceae) aerial part is widely used for medicinal purposes. To evaluate its anti-inflammatory, antinociceptive and antipyretic activities, two concentrations of the extract and its fractions were tested in carrageenan-induced rat paw oedema, hot-plate test model in mice and brewer's yeast-induced pyrexia in mice. The antioxidant power of the extract, its fractions and isolated compounds was studied using DPPH scavenging and beta-carotene/linoleic acid tests. The ethyl acetate fraction of a methanol extract was found to be the most active fraction and exhibited the highest inhibition of inflammation (67%) and the highest inhibition of oxidation of beta-carotene (92%). Bioassay-guided fractionation of the ethyl acetate fraction was carried out and three flavonoid glycosides were isolated for the first time from this species: (1) quercetin 3-O-beta-L-galactopyranoside, (2) quercetin 3-O-beta-L-arabinopyranoside and (3) quercetin 3-O-alpha-L-rhamnopyranoside. The present results confirmed the traditional use of L. regularis and clearly indicate that the plant could be a potential anti-inflammatory and antioxidant agent. (C) 2011 Elsevier Ltd. All rights reserved.