Inhibition of mammalian 5-lipoxygenase and cyclo-oxygenase by flavonoids and phenolic dietary additives

Laughton, Miranda J.; Evans, Patricia; Moroney, Michele A.; Hoult, J.R.S.; Halliwell, Barry

doi:10.1016/0006-2952(91)90501-u

Cited by 564 publications

(283 citation statements)

References 24 publications

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“…While there was no evidence of modulation of cyclooxygenase activity during this human intervention trial there have been reports of altered cyclooxygenase and lipoxygenase activities in various in vitro animal or cell culture systems Laughton et al, 1991;Kim et al, 1998). This may re¯ect the signi®cantly higher¯avo-noid concentrations used in in vitro studies (10 ± 50 mM; Mower et al, 1984) compared with those achieved following 6 weeks' rutin supplementation (mean plasma quercetin concentration 0.14 + 0.03 mmolal plasma).…”

Section: Discussionmentioning

confidence: 82%

Bioavailability and efficiency of rutin as an antioxidant: a human supplementation study

Boyle¹,

Dobson²,

Duthie³

et al. 2000

Eur J Clin Nutr

179

107

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Objective: To determine the potential antioxidant effect of rutin (quercetin-3-O-b-rutinoside) supplementation. Design: A 6-week randomized single-blind placebo controlled trial was conducted; 500 mg rutin supplement was compared to an equivalent amount of glucose placebo. In addition, a pharmacokinetic study was carried out. Setting: The Rowett Research Institute, Aberdeen, UK. Subjects: Eighteen healthy non-obese normocholesterolaemic female volunteers in the age range 18 ± 48 y. Main outcome measures: Plasma¯avonoids, ascorbic acid, tocopherols and carotenoids, plasma antioxidant capacity, lymphocyte DNA damage, blood chemistry and haematology, liver function tests, urinary malondialdehyde, 8-hydroxy-2H -deoxyguanosine and 8-iso-prostaglandin F 2a . Results: Eighteen volunteers completed the trial. Rutin supplementation did not induce any adverse changes in blood chemistry or indices of liver function. Plasma¯avonoids were signi®cantly elevated in the rutinsupplemented group. Endogenous oxidation of pyrimidines was signi®cantly decreased in both rutin-and placebo-treated volunteers. There was no signi®cant change in the level of urinary 8-hydroxy-2 H -deoxyguanosine or urinary malondialdehyde in either group. A linear correlation was observed between urinary malondialdehyde and urinary 8-iso-prostaglandin F 2a (R 0.54, P`0.01). Conclusion: Six weeks' rutin supplementation signi®cantly elevated the levels of three plasma¯avonoids (quercetin, kaempferol and isorhamnetin) but there was no signi®cant change in plasma antioxidant status. The decrease in the level of endogenous base oxidation in lymphocyte DNA seen in both the placebo-and rutinsupplemented subjects may re¯ect seasonal changes in other dietary antioxidants.

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Section: Discussionmentioning

confidence: 82%

Bioavailability and efficiency of rutin as an antioxidant: a human supplementation study

Boyle¹,

Dobson²,

Duthie³

et al. 2000

Eur J Clin Nutr

179

107

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“…In earlier studies it was shown that fisetin is an effective inhibitor of 5-LOX activity in stimulated peritoneal leukocytes [49]. As shown in Fig.…”

Section: Anti-inflammatory Effects Of Fisetinmentioning

confidence: 76%

Modulation of multiple pathways involved in the maintenance of neuronal function during aging by fisetin

Maher

2009

Genes Nutr

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Multiple factors have been implicated in the age-related declines in brain function. Thus, it is unlikely that modulating only a single factor will be effective at slowing this decline. A better approach is to identify small molecules that have multiple biological activities relevant to the maintenance of brain function. Over the last few years, we have identified an orally active, novel neuroprotective and cognition-enhancing molecule, the flavonoid fisetin. Fisetin not only has direct antioxidant activity but it can also increase the intracellular levels of glutathione, the major intracellular antioxidant. Fisetin can also maintain mitochondrial function in the presence of oxidative stress. In addition, it has anti-inflammatory activity against microglial cells and inhibits the activity of 5-lipoxygenase, thereby reducing the production of lipid peroxides and their pro-inflammatory by-products. This wide range of actions suggests that fisetin has the ability to reduce the age-related decline in brain function.

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“…There was also no change in the susceptibility of the LDL to oxidative modi®cation over the 3 h after ingestion suggesting the tea¯avonoids were not present in high enough quantities in the LDL at this time to provide a measurable change in susceptibility to oxidation. This might indicate that¯avonoids are not absorbed ef®ciently into the plasma after ingestion (Lee et al, 1995). Alternatively, the incorporation of¯avonoids into LDL might require a longer period of time, given that the half life of LDL is 1±2 d. Therefore a chronic tea consumption study was carried out using a quantity of black tea suf®cient to increase total¯avonoid intake by 126.8 AE 13.5 mg/d.…”

Section: Discussionmentioning

confidence: 99%

“…Transition metals such as iron and copper are important pro-oxidants; some¯avo-noids can chelate divalent metal ions, hence preventing free radical formation (de-Whalley et al, 1990). Extensive in vitro studies have found most of the main dietary¯avo-noids to be effective in protecting against the oxidative modi®cation of LDL (de-Whalley et al, 1990;Laughton et al, 1991;Morel et al, 1993;Rankin et al, 1993;Igarashi & Ohmuma, 1995;Fuhrman et al, 1995). Speci®cally, the ability of tea catechins to protect LDL against oxidative modi®cation has been investigated, with (7)-epigallocatechin (EGC), ( )-catechin (C), (7)-epicatechin (EC), (7)-epicatechingallate (ECG) and (7)-epigallocatechingallate (EGCG) all having a signi®cantly protective effect (NegreSalvayre et al, 1991).…”

Section: Introductionmentioning

confidence: 99%

Black tea consumption does not protect low density lipoprotein from oxidative modification

Mcanlis¹,

McEneny²,

Pearce³

et al. 1998

Eur J Clin Nutr

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Objective: To investigate the in vivo and in vitro effects of black tea on the oxidative modi®cation of low density lipoprotein (LDL). Design: The antioxidant activity of the tea was studied in vitro by measuring the resistance of the LDL to oxidative modi®cation in the presence of copper. The effects of tea consumption in vivo were investigated in two settings. Firstly, to assess the acute effects of tea consumption, ®ve fasting healthy subjects ingested 600 mls (50.7 AE 5.4 mg¯avonoids) of black tea and peripheral venous blood was collected at 0, 30, 60, 90, 120 and 180 min after consumption. Secondly, to assess the effects of chronic tea consumption, a randomised crossover trial of tea (126.8 AE 13.5 mg¯avonoids) and coffee consumption was carried out in ten healthy subjects. Results: Black tea extract increased the resistance of LDL in vitro in a concentration dependent manner. There was no signi®cant change in total plasma antioxidant capacity or susceptibility of the LDL to oxidation over the 3 h period after consumption of black tea. The four-week crossover study in which coffee was used as a control against the black tea showed no signi®cant difference in the total plasma antioxidant capacity or susceptibility of LDL to oxidation between the tea and coffee groups. Serum lipids, including total cholesterol, triglycerides, LDL cholesterol and HDL cholesterol did not change signi®cantly throughout the study. Conclusions: The consumption of moderate quantities of black tea acutely or for one week does not increase plasma total antioxidant capacity or alter the susceptibility of LDL to oxidation. Sponsorship: This work was funded by the Department of Agriculture for Northern Ireland.

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Inhibition of mammalian 5-lipoxygenase and cyclo-oxygenase by flavonoids and phenolic dietary additives

Cited by 564 publications

References 24 publications

Bioavailability and efficiency of rutin as an antioxidant: a human supplementation study

Bioavailability and efficiency of rutin as an antioxidant: a human supplementation study

Modulation of multiple pathways involved in the maintenance of neuronal function during aging by fisetin

Black tea consumption does not protect low density lipoprotein from oxidative modification

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