NQO1
NAD(P)H Quinone Dehydrogenase 1 (NQO1) is an enzyme with antioxidant capacities and is encoded for by the NQO1 gene 1. Quinones are a family of bio-active compounds with important roles in energy intensive pathways, for example aerobic respiration which is responsible for generating ATP molecules, which can be thought of as the easily transportable energy currency of the body. Due to their use in energy intensive pathways quinone molecules can often form reactive oxygen species if not oxidised completely 3. NQO1 functions to ensure any partially oxidised quinone molecules, which are highly reactive, are fully oxidised and then excreted from the body.
This function can even be used protectively by the cell, with quinone molecules often embedded in cell membranes to act as a buffer for any potentially harmful reactive oxygen species. Following a reaction these quinone molecules can be rapidly processed and excreted by NQO1, thus protecting the cell 4.
There is one SNP in the NQO1 gene which is associated with poor health outcomes, rs1800566 or C559T.
| rsID Number | Major Allele | Minor Allele | Minor Allele Frequency (%) | Major Amino Acid | Minor Amino Acid |
|---|---|---|---|---|---|
| rs1800566 | c | t | 25 | Pro | Ser |
Risk Description
The risk ‘T’ allele of C559T in the NQO1 gene is associated with an increased overall cancer risk 5. It is thought this is driven by structural changes, induced by the inclusion of a serine rather than a proline amino acid with the risk ‘T’ allele, leading to a loss of enzyme activity due to a poorer association between NQO1 and its vitamin B2 cofactor 6. This loss of enzyme activity reduces the antioxidant capacity of the body increasing the risk of cancer, and leading to a poorer prognosis post diagnosis 7,8.
Direct Nutrients:*
| Ingredient | Active Ingredient | Effect |
|---|---|---|
| Vitamin B2 | Riboflavin phosphate |
Vitamin B2 is a cofactor for NQO1, and is required for it to function correctly 9. Therefore, supplementation may benefit those carrying the risk ‘T’ allele of C559T, which is associated with impaired co-factor binding. Ensuring a proper supply of vitamin B2 will ensure that this is not the limiting factor for NQO1 activity. |
Indirect Nutrients:*
| Ingredient | Active Ingredient | Effect |
|---|---|---|
| Glutathione |
The risk ‘T’ allele of C559T is associated with a poorer antioxidant capacity which may be associated with a reduction in intracellular glutathione, a potent antioxidant 10. Glutathione supplementation may therefore benefit those carrying the risk ‘T’ allele of C559T. |
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Discuss this information with your doctor before taking any course of action.
Citations:
- https://www.ncbi.nlm.nih.gov/pubmed/2843525
- https://www.ncbi.nlm.nih.gov/pubmed/15047100
- https://www.ncbi.nlm.nih.gov/pubmed/12093358
- https://www.ncbi.nlm.nih.gov/pubmed/7649491
- https://www.ncbi.nlm.nih.gov/pubmed/23860519
- https://www.ncbi.nlm.nih.gov/pubmed/25143260
- https://www.ncbi.nlm.nih.gov/pubmed/11160862
- https://www.ncbi.nlm.nih.gov/pubmed/18511948
- http://www.chem.qmul.ac.uk/iubmb/enzyme/EC1/6/5/2.html
- https://www.ncbi.nlm.nih.gov/pubmed/21034357