Do polyphenols enter the brain and does it matter? Some theoretical and practical considerations

Genes & Nutrition

Table 2 PPs concentrations in plasma and animal brain obtained from studies using either exsanguinated and perfused animals or correcting for residual blood by other means

No.	PP measured	Plasma conc.	Correction achieved by	Brain conc. corrected	References
Section I: studies in exsanguinated and perfused animals
1	Epicatechin metabolites (total)	66 uM	Perfusion	0.4 nmol/g tissue (estimated)	Abd El Mohsen et al. (2002)
2	Pelargonidin metabolites (total)	2 h: ~1.5 uM	Perfusion	2 h: 0.16 nmol/g tissue [43 ng/g]	El Mohsen et al. (2006)
2	Pelargonidin metabolites (total)	18 h: ~0.65 uM	Perfusion	18 h: <LOD	El Mohsen et al. (2006)
3	(+)-Catechin	<LOD	Perfusion	53 ng/g tissue	Prasain et al. (2009)
4	Catechin	1.98 ug/ml	Perfusion	0.57 ng/g tissue	Ferruzzi et al. (2009)
4	Epicatechin	3.86 ug/ml	Perfusion	0.29 ng/g tissue	Ferruzzi et al. (2009)
5	Cyanidin-3-glucoside	0.15 uM	Blood-less animals used; no explicit information on brain perfusion	0.21 nmol/g tissue	Talavera et al. (2005)
6	Epigallocatechin-3-gallate	12.3 uM	Perfusion	0.5 nmol/g tissue	Nakagawa and Miyazawa (1997)
7	Quercetin	No details given	Perfusion	40.1 pmol/g tissue	Ishisaka et al. (2011)
Section II: studies correcting for residual blood
8	Quercetin	7.7 umol/l	Hb method	<LOD	de Boer et al. (2005)
	Isorhamnetin	15.7 umol/l		0.19 nmol/g tissue
	Tamarixetin	<LOD		0.14 nmol/g tissue
9	Quercetin	1.1 umol/l	Hb methods	0.22 nmol/g tissue
	Isorhamnetin	0.15 umol/l		<LOD
	Tamarixetin	<LOD		<LOD

ISSN: 1865-3499