Abstract: The aim of the present study was to evaluate the in vitro antioxidant and in vivo photoprotectiveactivities of an ethanolic extract of CulcitiumreflexumH.B.K.leaves (ECR extract). The antioxidantactivity of the extract was assessed by means of three different in vitro tests: (1) bleaching of the stable 1,1-diphenyl-2-picrylhydrazyl radical; (2) peroxidation, induced by the water-soluble radical initiator 2,2′-azobis(2-amidinopropane)hydrochloride, on mixed dipalmitoylphosphatidylcholine/linoleic acid unilamellar vesicles; (3) UV radiation-induced peroxidation in phosphatidylcholine multilamellar vesicles. In all in vitro tests used the ECR extract showed a significant antioxidant effect. Furthermore, a gel formulation containing this extract proved, when topically applied, to afford a significant in vivo protection against UV-B-induced skin erythema in healthy human volunteers. Then, by chromatographic fractionation and spectroscopic methods, we identified some cinnamic acid derivatives and the majorflavonoid constituents of the ECR extract, viz. the flavonols rutin, quercetin-3-O-β-d-galactopyranoside-4′-O-β-d-glucopyranoside, quercetin-3-O-β-d-glucopyranoside, isorhamnetin-3-O-β-d-galactopyranoside, quercetin and kaempferol.
Antioxidant and photoprotective activity of a crude extract of Culcitium reflexum H.B.K. leaves and their major flavonoids
AQUINO, Rita Patrizia;
2002-01-01
Abstract
Abstract: The aim of the present study was to evaluate the in vitro antioxidant and in vivo photoprotectiveactivities of an ethanolic extract of CulcitiumreflexumH.B.K.leaves (ECR extract). The antioxidantactivity of the extract was assessed by means of three different in vitro tests: (1) bleaching of the stable 1,1-diphenyl-2-picrylhydrazyl radical; (2) peroxidation, induced by the water-soluble radical initiator 2,2′-azobis(2-amidinopropane)hydrochloride, on mixed dipalmitoylphosphatidylcholine/linoleic acid unilamellar vesicles; (3) UV radiation-induced peroxidation in phosphatidylcholine multilamellar vesicles. In all in vitro tests used the ECR extract showed a significant antioxidant effect. Furthermore, a gel formulation containing this extract proved, when topically applied, to afford a significant in vivo protection against UV-B-induced skin erythema in healthy human volunteers. Then, by chromatographic fractionation and spectroscopic methods, we identified some cinnamic acid derivatives and the majorflavonoid constituents of the ECR extract, viz. the flavonols rutin, quercetin-3-O-β-d-galactopyranoside-4′-O-β-d-glucopyranoside, quercetin-3-O-β-d-glucopyranoside, isorhamnetin-3-O-β-d-galactopyranoside, quercetin and kaempferol.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
