Flavonoids with Potent Antioxidant Activity Found in Young Green Barley Leaves

Abstract

Saponarin, a flavonoid found in young green barley leaves, possesses potent antioxidant activities, which are determined by its inhibition of malonaldehyde (MA) formation from various lipids oxidized by UV light or Fenton's reagent. Lipids used were squalene, ethyl linoleate, ethyl linolenate, ethyl arachidonate, octadecatetraenoic acid (ODTA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), cod liver oil, lecithin I, lecithin II, and blood plasma. The addition of saponarin inhibited the formation of MA from squalene upon UV irradiation at the level of 2 μmol/mL by almost 100%, whereas BHT inhibited its formation by 75% at the same level. Saponarin showed potent antioxidant activity toward fatty acid ethyl esters at levels >100 μg/mL. Saponarin inhibited MA formation in ODTA by 60%, in EPA by 50%, and in DHA by 43% at the level of 15 μmol/mL. Saponarin exhibited strong antioxidant activities with dose-response levels toward cod liver oil and lipoproteins (lecithins I and II), higher than those of α-tocopherol. A mixture of saponarin/lutonarin (4.5:1, w/w) inhibited MA formation appreciably from all lipids tested with dose response. This mixture exhibited highest effect toward cod liver oil (86%), followed by DHA, lecithin II, blood plasma, EPA, and lecithin I. Supplementation of young green barley leaves containing saponarin should be beneficial to health and may prevent diseases caused by oxidative damage such as various cancers, inflammations, and cardiovascular diseases.

Flavonoid rich extract of Murraya Koenigii alleviates in-vitro LDL oxidation and oxidized LDL induced apoptosis in raw 264.7 Murine macrophage cells

“…However, MK extract successfully prevented ApoB fragmentation which is indicated by black arrow in respective wells established free radical scavenging and metal chelating properties of MK leaves that prevents oxidative modification of LDL. High contents of total flavonoids present in MK leaf extract possibly favour prevention of LDL oxidation which is in agreement with other flavonoid rich extracts with potent anti-oxidant and free radical scavenging potentials (Chograni et al 2013;Kamiyama and Shibamoto 2012;Bitis et al 2010). …”

First Synthesis of Saponarin, 6-<i>C</i>- and 7-<i>O</i>-Di-<i>β</i>-D-glucosylapigenin

“…C,O-Diglycosylflavonoides also show various bioactivities. Among them, saponarin, 6-C-and 7-O-di-β-dglucopyranosyl-4′,5,7-trihydroxyflavone has shown potent antioxidant, 2,3) hematoprotective, 4) and hypoglycemic 5) activities. In the synthesis of C,O-diglycosylflavonoides, that of flavocommelin, 6-C-and 4′-O-di-β-d-glucopyranosyl-7-Omethyl-4′,5,7-trihydroxyflavone has been reported only by Oyama and Kondo.…”

Health promoting properties of young barley

“…Późniejsze badania przeprowadzone przez Markham i Mitchell wykazały, że głównymi antyoksydantami w liściach młodego jęczmienia są: C-glikozydy flawonowe, saponaryna i lutonaryna [33]. Te dwa wyizolowane z trawy jęczmiennej unikalne glikozydy flawonoidów -saponaryna (7-0-GIV) oraz lutonaryna (7-0-GIO) -biorą również udział w hamowaniu tworzenia aldehydu malonowego [33,34,35,36,37]. Przeprowadzone przez Kamiyama i Shibamoto badania nie tylko potwierdziły przeciwutleniające działanie ww.…”