Berry polyphenols: bioactivities and health benefits
1
Berry Polyphenols: Bioactivities and Health Benefits Gordon McDougall and Derek Stewart, Plant Products & Food Quality Programme, Scottish Crop Research Institute, Dundee DD2 5DA, Scotland, U.K. Rasp Rasp-UB Strawberry Blackcurrant Blueberry 0 1 2 3 4 5 6 10 30 50 70 90 Ki value Anthocyanin/phenol ratio -10 10 30 50 70 90 110 0 100 200 300 400 500 Phenols ( µ g) % Inhibition red cabbage straw berry blackcurrant blueberry raspberry Conclusions The recent joint expert report by WHO and FAO (1) concerning the relation between nutrition and chronic and degenerative diseases concluded that a convincing association exists relating the consumption of fruits (and vegetables) and reduced risk of cardiovascular disease (CVD) and some cancers. However, the derivation of the beneficial, protective effect remains unclear although several studies point indicate that plant antioxidants could be important. In this poster, we show four examples in which polyphenols from berries have bioactivies that could have beneficial effects on key health issues . References . 1. anon. (2002). Diet, nutrition and the prevention of chronic diseases. World Health Organisation, Geneva, Switzerland. 2. McDougall et al. J Agric Food Chem. 53, 2760. 3. Mylnikov et al. (2005) J. Agric Food Chem. 53, 7728. 4. Ross et al. (2006) Phytochemistry, in press. Acknowledgements We acknowledge funding from the Scottish Executive Environmental and Rural Affairs Department, the British Heart Foundation and The EU Northern Periphery Programme. A polyphenol-rich but vitamin C free extract of raspberry (Rubus ideaus) was prepared that had an ellagitannin:anthocyanin ratio of ~2:1. This was used in serial dilution organ bath studies to determine their effect on the suppression of superoxide (O 2 ¯) in rat abdominal and thoracic arteries and NO bioavailability in carotid arteries. O 2 ¯ is accepted as a endothelial dysfunction agent whilst NO is a mediator involved in several endothelial functions including relaxation and vessel flexibility. • The raspberry extract, even at remarkably low levels, exerts a significant ability to scavenge O 2 ¯. (Fig 1) with both the original and “bioavailable” (subject to in vitro digestion) extracts performing better than Vitamin C. • The raspberry extracts also exhibit beneficial effects on NO bioavailability (Fig 2). They were more effective than Vitamin C and quercetin glucuronide (QG) and sulphate (QS) - known effective dietary components - at a lower concentrations. Therefore, the raspberry polyphenols have the potential to beneficially influence CV performance. Berry extracts inhibited α-amylase activity with strawberry and raspberry being the most effective (Fig. 3). The concetration for half maximal inhibition was in the range that could be encountered in the small intestine after ingestion of berries. The most active components appeared to ellagitannins. The berry extracts also inhibited α-glucosidase activity but the order of effectiveness was different (Fig. 4). The most effective extracts appeared to be anthocyanin-rich. There is considerable potential for synergy between different berry polyphenolic components to inhibit starch digestion and thereby modulate blood glucose levels in vivo (2). A fruit fly (Drosophila melanogaster) model was used to study the effect of dietary supplementation with red and yellow cloudberry juices (Rubus chamaemorus) with high and low anthocyanin respectively. Primary (conjugated hydroperoxides) and secondary (ketodienes) products of lipid peroxidation (age-related oxidative damage) was measured at different age points and in both sexes (Fig. 5). There were age-related and sex related differences (3). • Young females experienced significant reductions in primary and secondary oxidation with both juices. • Young males experienced significant reductions in primary and secondary oxidation following supplementation with yellow and red juices, respectively. • Older flies only experienced benefits with red juice and only then on secondary oxidation products (ketodienes) in males. Polyphenolic components of berries exert clear bioactivities such as reduced age-related oxidation, increased NO bioavailability, reduced cancer cell proliferation and control of blood glucose levels which have direct relevance to major health problems such as aging, cardiovascular disease, cancers and diabetes. We have begun to identify structure activity relationships for these bioactivities and we now aim to corroborate these results under in vivo conditions through suitably designed trials. Cardiovascular protection by Rubus phytochemicals and comparison with Quercetin Nitric Oxide Bioavailability 0 1 2 3 4 5 6 7 Vehicle Vit C (18μg/ml) RE (90 μg/ml) RE (18 μg/ml) RE (1.8 μg/ml) RE 0.36 μg/ml) RE (0.036 μg/ml) Vehicle QG (50μg/ml) QG (10μg/ml) QS (60μg/ml) QS (12μg/ml) QS (1.5μg/ml) Sample Figure 2 NO Bioavailability (AUC gm/gm) 0 20 40 60 80 100 120 1 2 3 4 7 Days % Viability 0 7.5 15 30 Study 1 - Cardiovascular-Protective Effects of Raspberry extracts Study 2 – Inhibition of Starch Digestion by Berry extracts Study 3 – Effects of Berry Supplementation on a Model System for Aging Study 4 - Effects of Raspberry Extracts on Cancer Cell Proliferation 0 20 40 60 80 100 120 1 2 3 4 7 Days % Viability 0 7.5 15 30 Raspberry extracts inhibit the proliferation of cancer cells in a dose-responsive manner (Fig. 6). The inhibition is not caused by anthocyanins as their complete removal potentiated the effectiveness of the extract (Fig. 7). Ellagitannins seem to be the most effective anti-proliferative agents and initial studies suggest that they break down in the presence of the cancer cells to form ellagic acid, which may be the key antiprolferative agent (4). Fig. 3 Fig. 4 Fig. 6 Fig. 7 Scavenging capacity of original and "bioavailable" raspberry extract for O 2 - 0 25 50 75 100 1 0 -1 -2 -3 log Phenols (μg. ml -1 ) Orignal Rasp Extr. Digested Rasp Extr. Vitamin C Superoxide Inhibition (%) Figure 1 Fig. 5 ®
Transcript of Berry polyphenols: bioactivities and health benefits
Berry Polyphenols: Bioactivities and Health Bene�ts Gordon McDougall and Derek Stewart, Plant Products & Food Quality Programme,
Scottish Crop Research Institute, Dundee DD2 5DA, Scotland, U.K.
Hyd
Rasp Rasp-UB Strawberry
Blackcurrant
Blueberry
0
1
2
3
4
5
6
10 30 50 70 90
Ki value
Ant
hocy
anin
/phe
nol r
atio
-10
10
30
50
70
90
110
0 100 200 300 400 500Phenols (µg)
% In
hibi
tion
red cabbage
straw berry
blackcurrant
blueberry
raspberry
Conclusions
The recent joint expert report by WHO and FAO (1) concerning the relation between nutrition and chronic and degenerative diseases concluded that a convincing association exists relating the consumption of fruits (and vegetables) and reduced risk of cardiovascular disease (CVD) and some cancers. However, the derivation of the bene�cial, protective e�ect remains unclear although several studies point indicate that plant antioxidants could be important. In this poster, we show four examples in which polyphenols from berries have bioactivies that could have bene�cial e�ects on key health issues .
References .1. anon. (2002). Diet, nutrition and the prevention of
chronic diseases. World Health Organisation, Geneva, Switzerland. 2. McDougall et al. J Agric Food Chem. 53, 2760. 3. Mylnikov et al. (2005) J. Agric Food Chem. 53, 7728. 4. Ross et al. (2006) Phytochemistry, in press.
AcknowledgementsWe acknowledge funding from the Scottish Executive
Environmental and Rural A�airs Department, the British Heart Foundation and The EU Northern Periphery Programme.
A polyphenol-rich but vitamin C free extract of raspberry (Rubus ideaus) was prepared that had an ellagitannin:anthocyanin ratio of ~2:1. This was used in serial dilution organ bath studies to determine their e�ect on the suppression of superoxide (O2¯) in rat abdominal and thoracic arteries and NO bioavailability in carotid arteries. O2¯ is accepted as a endothelial dysfunction agent whilst NO is a mediator involved in several endothelial functions including relaxation and vessel �exibility.
• The raspberry extract, even at remarkably low levels, exerts a signi�cant ability to scavenge O2¯. (Fig 1) with both the original and “bioavailable” (subject to in vitro digestion) extracts performing better than Vitamin C.
• The raspberry extracts also exhibit bene�cial e�ects on NO bioavailability (Fig 2). They were more e�ective than Vitamin C and quercetin glucuronide (QG) and sulphate (QS) - known e�ective dietary components - at a lower concentrations.
Therefore, the raspberry polyphenols have the potential to bene�cially in�uence CV performance.
Berry extracts inhibited α-amylase activity with strawberry and raspberry being the most e�ective (Fig. 3). The concetration for half maximal inhibition was in the range that could be encountered in the small intestine after ingestion of berries. The most active components appeared to ellagitannins.
The berry extracts also inhibited α-glucosidase activity but the order of e�ectiveness was di�erent (Fig. 4). The most e�ective extracts appeared to be anthocyanin-rich.
There is considerable potential for synergy between di�erent berry polyphenolic components to inhibit starch digestion and thereby modulate blood glucose levels in vivo (2).
A fruit �y (Drosophila melanogaster) model was used to study the e�ect of dietary supplementation with red and yellow cloudberry juices (Rubus chamaemorus) with high and low anthocyanin respectively. Primary (conjugated hydroperoxides) and secondary (ketodienes) products of lipid peroxidation (age-related oxidative damage) was measured at di�erent age points and in both sexes (Fig. 5).There were age-related and sex related di�erences (3).
• Young females experienced signi�cant reductions in primary and secondary oxidation with both juices.
• Young males experienced signi�cant reductions in primary and secondary oxidation following supplementation with yellow and red juices, respectively.
• Older �ies only experienced bene�ts with red juice and only then on secondary oxidation products (ketodienes) in males.
Polyphenolic components of berries exert clear bioactivities such as reduced age-related oxidation, increased NO bioavailability, reduced cancer cell proliferation and control of blood glucose levels which have direct relevance to major health problems such as aging, cardiovascular disease, cancers and diabetes. We have begun to identify structure activity relationships for these bioactivities and we now aim to corroborate these results under in vivo conditions through suitably designed trials.
Cardiovascular protection by Rubus phytochemicals and comparison with Quercetin
Nitric Oxide Bioavailability
01234567
Vehicle Vit C(18µg/ml)
RE (90µg/ml)
RE (18µg/ml)
RE (1.8µg/ml)
RE 0.36µg/ml)
RE (0.036µg/ml)
Vehicle QG(50µg/ml)
QG(10µg/ml)
QS(60µg/ml)
QS(12µg/ml)
QS(1.5µg/ml)
SampleFigure 2
NO
Bio
avai
labi
lity
(AU
C gm
/gm
)
0
20
40
60
80
100
120
1 2 3 4 7
Days
% V
iabi
lity
0
7.5
15
30
Study 1 - Cardiovascular-Protective E�ects of Raspberry extracts
Study 2 – Inhibition of Starch Digestion by Berry extracts
Study 3 – E�ects of Berry Supplementation on a Model System for Aging
Study 4 - E�ects of Raspberry Extracts on Cancer Cell Proliferation
0
20
40
60
80
100
120
1 2 3 4 7
Days
% V
iabi
lity 0
7.5
15
30
Raspberry extracts inhibit the proliferation of cancer cells in a dose-responsive manner (Fig. 6). The inhibition is not caused byanthocyanins as their complete removal potentiated the e�ectivenessof the extract (Fig. 7). Ellagitannins seem to be the most e�ective anti-proliferative agentsand initial studies suggest that they break down in the presence of thecancer cells to form ellagic acid, which may be the keyantiprolferative agent (4).
Fig. 3 Fig. 4
Fig. 6 Fig. 7
Scavenging capacity of original and "bioavailable" raspberry extract for O 2-
0
25
50
75
100
10-1-2-3log Phenols (µg. ml -1 )
Orignal Rasp Extr.Digested Rasp Extr.Vitamin CSu
pero
xide
Inhi
bitio
n (%
)
Figure 1
Fig. 5
®
