Phytonutrients - Anthocyanins

Question 1

Anthocyanins

Answer 1

Anthocyanins and their aglycone ‘anthocyanidins’ are blue, red and purple pigments found in a range of plants. They are protective against UV radiation in plants:
* Found in the tissues of plants including leaves, stems, roots, flowers and fruits.
aglycone = compound without a sugar group attached.

Question 2

Food sources:

Answer 2

• Acai berry, blackcurrant, blueberry, bilberry, cherry, red grape, purple corn.

Question 3

Functions:

Answer 3

• Cardiovascular health
• Type 2 diabetes
• Eye health
• Neurological health

Question 4

Cardiovascular health:

Answer 4

Functions:
* Antioxidant —scavenging ROS. Anti-inflammatory—inhibit NFκB. These effects protect against endothelial damage and reduce LDL oxidation.
* Improve blood lipids —↑HDLs, ↓LDLs, total cholesterol and triglycerides.
* Decrease arterial stiffness and reduce blood pressure.
* ↑insulin sensitivity (next slide).
Therapeutic uses:
* Hypertension.
* Atherosclerosis.
* Dyslipidaemia.
* Protective against peripheral arterial disease and coronary artery disease.

Question 5

Type 2 diabetes:

Answer 5

Functions:
* Improve insulin secretion and ↑ insulin sensitivity.
* Thought to activate the enzyme AMPK, which:
o Upregulates GLUT4 (transports glucose into cells).
o Inhibits glucose production in the liver.
* Antioxidant and anti-inflammatory properties help protect against diabetic complications including retinopathy and neuropathy.
AMPK= adenosine monophosphate-activated protein kinase

Question 6

Eye health:

Answer 6

Functions:
* Protect ocular tissue from oxidative stress.
* Improve night vision (protects photoreceptor cells).

Question 7

Neurological health:

Answer 7

Functions:
* Able to cross the blood brain barrier to exert neuroprotective effects.
* Reduce damaging effects of processes that contribute to neurodegeneration including oxidative stress, excitotoxicity and glial inflammation.
* Support cognitive performance with improvements in memory and learning.
Therapeutic uses: Neurodegenerative conditions such as:
* Alzheimer’s disease.
* Parkinson’s disease.
* Motor neurone disease.
* To protect against:
* Cerebral ischemia.
* Age-related memory loss.
glial cells = the nervous systems supportive cells

Question 8

Dosage:

Answer 8

• Moderate amounts of anthocyanins e.g. 1/3 cup of blueberries daily, are associated with reduced risk of cardiovascular disease, Type 2 diabetes and neurological decline (equivalent anthocyanins 25–50 mg).
• Doses of between 25–50 mg daily have shown to support visual health.
• Supplemental doses of up to 640 mg anthocyanins daily in adults have been used for cardiovascular issues with no reported adverse effects.

Question 9

Safety:

Answer 9

• Dietary intake is recognised as safe and unlikely to cause harm.

Question 10

Interactions:

Answer 10

• Many anthocyanins have been identified as inhibitors of BRCP-mediated transport, theoretically increasing bioavailability of certain drugs including:
  o Anticancer agents (mitoxantrone, topotecan, tyrosine kinase inhibitors); antibiotics (fluoroquinolones); B-blockers (prazosin).
• High intakes (e.g. from supplements) could increase the risk of bleeding when taken with anticoagulant drugs.
  BRCP-mediated transport = an ATP-dependent pump