Synergistic Antioxidative Effects of Alkamides, Caffeic Acid Derivatives, and Polysaccharide Fractions from Echinacea purpurea on in Vitro Oxidation of Human Low-Density Lipoproteins

Abstract

Preparations of Echinacea are widely used as alternative remedies to prevent the common cold and infections in the upper respiratory tract. After extraction, fractionation, and isolation, the antioxidant activity of three extracts, one alkamide fraction, four polysaccharide-containing fractions, and three caffeic acid derivatives from Echinacea purpurea root was evaluated by measuring their inhibition of in vitro Cu(II)-catalyzed oxidation of human low-density lipoprotein (LDL). The antioxidant activities of the isolated caffeic acid derivatives were compared to those of echinacoside, caffeic acid, and rosmarinic acid for reference. The order of antioxidant activity of the tested substances was cichoric acid > echinacoside > or = derivative II > or = caffeic acid > or = rosmarinic acid > derivative I. Among the extracts the 80% aqueous ethanolic extract exhibited a 10 times longer lag phase prolongation (LPP) than the 50% ethanolic extract, which in turn exhibited a longer LPP than the water extract. Following ion-exchange chromatography of the water extract, the majority of its antioxidant activity was found in the latest eluted fraction (H2O-acidic 3). The antioxidant activity of the tested Echinacea extracts, fractions, and isolated compounds was dose dependent. Synergistic antioxidant effects of Echinacea constituents were found when cichoric acid (major caffeic acid derivative in E. purpurea) or echinacoside (major caffeic acid derivative in Echinacea pallida and Echinacea angustifolia) were combined with a natural mixture of alkamides and/or a water extract containing the high molecular weight compounds. This contributes to the hypothesis that the physiologically beneficial effects of Echinacea are exerted by the multitude of constituents present in the preparations.

The economic potential of beach-cast seagrass – Cymodocea nodosa: a promising renewable source of chicoric acid

“…The activity of CA against herpes simplex virus has been demonstrated (Binns et al 2002). The antioxidant activity of CA was found to be comparable with that of rosmarinic acid (Dalby-Brown et al 2005).…”

Antioxidative activity of Ginkgo, Echinacea, and Ginseng tinctures

“…Antioxidants are compounds that protect cells against the damaging effects of reactive oxygen species (3). Experimental studies were performed on three plants that have antioxidative properties -Ginkgo biloba, Panax ginseng, and Echinacea purpurea (4). Ginkgo biloba preparations are used in the treatment of Parkinson's and Alzheimer's diseases caused by oxidative stress.…”

Rabbit dietary supplementation with pale purple coneflower. 1. Effects on the reproductive performance and immune parameters of does

“…In the present study, the effect of EPAL has only been observed for Bas. According to the results of other studies, this effect may be related to the phytochemically active constituents of EPAL (Hu and Kitts, 2000;Dalby-Brown et al, 2005;Pellati et al, 2005).…”

“…The chromatographic analysis reported 0.37% echinacoside. Echinacoside, which is responsible for the immunostimulatory action of Echinacea extracts (Hu and Kitts, 2000;Dalby-Brown et al, 2005;Pellati et al, 2005), was found to be the main caffeic acid derivative in EPAL extract. Echinacoside has frequently been studied for its antioxidant, anti-inflammatory and cicatrising activities (Speroni et al, 2002).…”