Dietary activators of antioxidant response element-linked gene expression for good vascular health screening strains of fruits, vegetables and related oils for activators of transcription factor nrf2
Guy Barker,1 Vicky Buchanan-Wollaston,1,3 Sudhesh Kumar,2 Dave Pink,1 Naila Rabbani,2,3 David Rand3 and Paul J. Thornalley2,3
1WarwickHRI, University of Warwick, Wellesbourne, CV35 9EF 2Clinical Sciences Research Institute, Warwick Medical School, University Hospital, Coventry CV2 2DX, and 3Warwick Systems
Biology Centre, University of Warwick, Coventry House, Coventry CV4 7AL
Fruit and particularly Brassica vegetables (broccoli, cabbage, cauliflower and Brussels sprouts) are important components of a healthy diet because they
have high levels of bioactive compounds linked to low risk of heart disease. The key to their benefit is probably the ability of these bioactive compounds
to induce and increase endogenous defences against blood vessel damage and counter the development of high cholesterol and lipids in the body.
Transcription factor NF-E2-related factor-2 (nrf2) regulates the transcription of a battery of genes encoding proteins with antioxidant and detoxification
activities and also genes encoding proteins involved in lipid and cholesterol synthesis. Activation of nrf2 increases the expression of antioxidant and
detoxification-related proteins and decreases the expression of lipogenic proteins.
Our DRINC project involves screening
strains of fruits and vegetables (broccoli,
rocket salad, tomatoes, carrots, onions) for
types
and
amounts
of
bioactive
compounds that are activators of
transcription factor nrf2 (omega-3 fatty
acids, carotenoids, glucosinolate-derived
isothiocyanates, polyphenols, flavonoids
and alkyl disulphides).
Figure 1: Illustrates some of the diversity available for
carrots and onions (colour differences can be caused by
some of the compounds to be assayed)
Figure 2: Illustrates the diversity in fatty acids within some B. oleracea strains within our
diversity sets. 18:3n3 is a-linolenic acid which is one of the Omega 3 fatty acids which will
be investigated.
18:1n9c
22:1n9
18:1n9c
22:1n9
18:1n9c
22:1n9
20:1n9
18:2n6c
18:2n6c
18:3n3
18:3n3
18:2n6c
18:3n3
B. oleracea gemmifera
(Brussels Sprout)
B. oleracea italica
(Inbred Broccoli)
B. oleracea italica
(Doubled haploid Broccoli)
GD33
M a r3 4
X
12 0
10 0
80
60
40
20
0
0
1
2
3
D a ys a t 15 oC
By using knowledge of the plant and its genetics we
properties through
can alter the post harvest
breeding (Figure 4). In this example we have shown
we can extend the shelf life of broccoli following
harvest. Such techniques could also be used to
maximise the nrf-2 activators present in the harvest
crop.
DH
H offsprin
offsp ring
D is trib utio n o f ye llo w ing of DH lin e s
5 .00
M ar3 4
4 .50
4 .00
F1
3 .50
3 .00
G D33
2 .50
2 .00
1 .50
1 .00
0 .50
0 .00
MG364
Vit C Amount mg/100g fwt
Figure 3: Vitamin C level measured in harvested broccoli heads
4
We have developed diversity sets for a number of these vegetables which represent the genetic
diversity found within the crop and have demonstrated already that there is a considerable
variation in the content of some of these compounds within different varieties of the same
vegetable (Figure 1 and 2).
For further information contact: guy.barker@warwick.ac.uk
Figure 4: Offspring of a cross between two broccoli strains showing how natural
variation can be exploited to identify genetic markers linked to enhanced shelf life
Properties of the plants change after harvest (see Figure 3) If
the levels of activators of the nrf2 pathway are affected then
this might have substantial health implications.