X-Message-Number: 27727 Date: Fri, 17 Mar 2006 19:40:25 -0800 (PST) From: Doug Skrecky <> Subject: inhibition of brain edema by quercetin liposomes [Quercetin by itself does not cross the blood-brain barrier. Like resveratrol, quercetin is effective in vitro for increasing (antiaging) sirtuin levels. However unlike (expensive) resveratrol, quercetin does not increase animal lifespan. There is a possibility that liposome encapsulated quercetin might perform differently in this regard, since many aging processes are thought to be mediated through the central nervous system.] Mech Ageing Dev. 2006 Apr;127(4):391-7. Epub 2006 Feb 9. Mannosylated liposomal flavonoid in combating age-related ischemia-reperfusion induced oxidative damage in rat brain. Active oxygen species alter the activities of the enzymes involved in the defence against free radicals and substantially influence the aging process and age-dependant neuropathology. Unilamellar liposomes were used to deliver flavonoidal antioxidant quercetin (QC) to rat brain. Antioxidant potential of QC loaded in mannosylated (QC 7.2mumol/kgb.wt.) liposomes (50nm) was investigated by an in vivo model of cerebral ischemia and reperfusion on Sprague Dawley young (2 months old, b.wt. 160-180g) and aged (20 months old, b.wt. 415-440g) rats. Animals were made ischemic for 30min by bilateral clamping of the common carotid artery followed by a 30min cerebral reperfusion by withdrawing the clamping. Diene level and (GSSG/GSH) ratio were found to be higher in normal aged, compared to normal young rat brain. Superoxide dismutase, catalase, glucose-6-phosphate dehydrogenase, glutathione reductase and glutathione S-transferase activities were lower in normal aged rat brain. Further reduction of these antioxidant enzymes was observed in aged rat brain by the induction of cerebral ischemia and reperfusion. Mannosylated liposomally encapsulated QC treatment resulted in a significant preservation of the activities of antioxidant enzymes and a marked inhibition of cellular edema formation in neuronal cells of young and old rats. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=27727