4. Divide the (25-week-old) obese C57BL/6J DIO mice (day
0 of the experiment) by weight-matching into three experimental groups and continue to feed animals on the HFD.
Maintain the LFD-fed group on the LFD.
5. At day 0, start the treatment. Give the mice of the LFD-fed
group and of one HFD-fed group the vehicle (olive oil); these
will serve as, respectively, LFD-fed and HFD-fed reference
groups. Treat the other two HFD-fed groups with an emulsion
of the selected pure carotenoid, mix or extract (see Notes 9 and
10) at two different doses (see Note 11). Conduct the treatments and prepare carotenoid emulsions as indicated in step 5
of Subheading 3.1.
6. Continue the nutritional and treatment challenge for 5 weeks.
7. Regularly monitor body weight and food intake (twice per
week). The last week of the experiment, it is advisable to
perform analysis and tests in live animals as listed in step 8 of
Subheading 3.1.
8. On day 35 (week 5 of treatment), proceed to the euthanization
and tissue collection, as in steps 9–12 of Subheading 3.1.
3.3 Model to Assess
the Potential
of Carotenoids to Act
as Coadjuvants
in Weight Loss
Strategies
Here we propose a protocol to investigate the potential of carotenoids to act as coadjuvants in weight loss strategies (e.g., together
with a low fat diet) by studying their ability to favor body weight/
fat loss and metabolic recovery in DIO mice (see Notes 1 and 2)
upon switching from the obesogenic HFD to a regular LFD.
(As indicated in Subheadings 3.1 and 3.2, if knockout mouse
models deficient for carotenoid-dioxygenases (see Note 3) are
used, this will allow dissecting the effects of parent carotenoids
apart from the effects of derived apocarotenoid products.
1. Perform the experiments with 4–6-week-old (see Note 2)
C57BL/6J (see Note 4) male (see Note 5) mice, and proceed
to induce DIO and metabolic derangements through HFD
(45% energy as fat) feeding for 20 weeks, as described in
steps 1–3 in Subheading 3.2.
2. Distribute the (25-week-old) C57BL/6 J DIO mice (day 0 of
the experiment) by weight-matching into four experimental
groups. Switch three experimental groups to the LFD and
maintain an experimental group on the HFD. Maintain the
LFD-fed group on the LFD.
3. At day 0, start the treatment. Give the mice of the LFD-fed
group, HFD-fed group and of one reverted HFD-fed group
the vehicle (olive oil); these will serve as, respectively, LFD-fed,
HFD-fed and reverted HFD-fed reference groups. Treat the
other two reverted HFD-fed groups with an emulsion of the
selected pure carotenoid, mix or extract (see Notes 9 and 10) at
410
Joan Ribot et al.
0 of the experiment) by weight-matching into three experimental groups and continue to feed animals on the HFD.
Maintain the LFD-fed group on the LFD.
5. At day 0, start the treatment. Give the mice of the LFD-fed
group and of one HFD-fed group the vehicle (olive oil); these
will serve as, respectively, LFD-fed and HFD-fed reference
groups. Treat the other two HFD-fed groups with an emulsion
of the selected pure carotenoid, mix or extract (see Notes 9 and
10) at two different doses (see Note 11). Conduct the treatments and prepare carotenoid emulsions as indicated in step 5
of Subheading 3.1.
6. Continue the nutritional and treatment challenge for 5 weeks.
7. Regularly monitor body weight and food intake (twice per
week). The last week of the experiment, it is advisable to
perform analysis and tests in live animals as listed in step 8 of
Subheading 3.1.
8. On day 35 (week 5 of treatment), proceed to the euthanization
and tissue collection, as in steps 9–12 of Subheading 3.1.
3.3 Model to Assess
the Potential
of Carotenoids to Act
as Coadjuvants
in Weight Loss
Strategies
Here we propose a protocol to investigate the potential of carotenoids to act as coadjuvants in weight loss strategies (e.g., together
with a low fat diet) by studying their ability to favor body weight/
fat loss and metabolic recovery in DIO mice (see Notes 1 and 2)
upon switching from the obesogenic HFD to a regular LFD.
(As indicated in Subheadings 3.1 and 3.2, if knockout mouse
models deficient for carotenoid-dioxygenases (see Note 3) are
used, this will allow dissecting the effects of parent carotenoids
apart from the effects of derived apocarotenoid products.
1. Perform the experiments with 4–6-week-old (see Note 2)
C57BL/6J (see Note 4) male (see Note 5) mice, and proceed
to induce DIO and metabolic derangements through HFD
(45% energy as fat) feeding for 20 weeks, as described in
steps 1–3 in Subheading 3.2.
2. Distribute the (25-week-old) C57BL/6 J DIO mice (day 0 of
the experiment) by weight-matching into four experimental
groups. Switch three experimental groups to the LFD and
maintain an experimental group on the HFD. Maintain the
LFD-fed group on the LFD.
3. At day 0, start the treatment. Give the mice of the LFD-fed
group, HFD-fed group and of one reverted HFD-fed group
the vehicle (olive oil); these will serve as, respectively, LFD-fed,
HFD-fed and reverted HFD-fed reference groups. Treat the
other two reverted HFD-fed groups with an emulsion of the
selected pure carotenoid, mix or extract (see Notes 9 and 10) at
410
Joan Ribot et al.