CYP1A1 is an important enzyme involved in the detoxication of toxic substances from our bodies. However, this enzyme can also activate some toxic compounds into cancer-causing agents. That is why some CYP1A1 gene variants make people more susceptible to certain kinds of cancer. Read on to find out more about CYP1A1, its genetics, and the natural substances that can increase or decrease CYP1A1 activity.
CYP1A1 is one of the cytochrome P450 monooxygenases (CYPs). These are enzymes that help eliminate most of the drugs and toxins from the human body (R).
CYP1A1 Function (Drug Metabolism)
- polycyclic aromatic hydrocarbons (PAHs), such as benzo[a]pyrene (R). PAHs are a group of more than 100 different chemicals that are released from burning coal, oil, gasoline, trash, tobacco, wood, or charcoal-broiled meat.
- estrogen (R, R).
When CYP1A1 processes PAHs, it can activate them as cancer-causing agents (R).
Unlike most other CYP enzymes, this one is mainly found outside of the liver, in tissues such as the lungs (R).
CYP1A1 the Good
CYP1A1 is important for the removal of toxic chemicals from our organism. Mice lacking this enzyme die within 30 days of benzo[a]pyrene treatment, whereas normal mice survive with no signs of toxicity (R).
Although this enzyme can activate cancer-causing substances, it primarily plays an important role in their detoxication (R).
It can also convert natural products found in food into anti-cancer agents (R).
CYP1A1 the Bad
CYP1A1 plays a major role in activating cancer-causing chemicals, such as PAHs (R).
It also activates tobacco-related cancer-causing N-nitrosamines, such as the NNK (R).
CYP1A1 Gene Polymorphism
The C variant (more active than the T variant) can increase susceptibility to DNA damage and cancer risk. In fact, rs4646903 was associated with leukemia, cervical, hepatocellular, lung, prostate, and head and neck cancers (meta-analysis, 268 studies, 55,963 cases, and 76,631 controls) (R, R, R).
Increasing or Decreasing CYP1A1
These natural substances increase CYP1A1 activity:
- Indole-3-carbinol, found in cruciferous vegetables (R).
- Resveratrol and resveratrol-containing foods (R).
- Andrographolide, from the Andrographis paniculata plant (R).
- Astaxanthin, a pigment found in most red-colored aquatic organisms like shrimps and some algae (R).
- Fish oil and garlic oil (R).
- Green and black tea (R).
These natural substances decrease CYP1A1 activity:
- Berries and their component ellagic acid can reduce CYP1A1 overactivity (R).
- Green tea extracts (R).
- Sulforaphane found in broccoli (R).
- St. John’s Wort (R).
- Lycopene, a red pigment found in tomatoes, carrots, and watermelon (R).
- Naringenin and 6′,7′-dihydroxybergamottin (from grapefruit juice) (R).
- Galangin, found in some plants (Alpinia officinarum, Alpinia galanga, and Helichrysum aureonitens) and propolis (R).
- Zyflamend, a widely used herbal formulation produced from the extracts of ten common herbs (rosemary, turmeric, ginger, holy basil, green tea, hu zhang, Chinese goldthread, barberry, oregano, and Baikal skullcap) (R).
These Both Increase and Decrease CYP1A:
Many foods appear to act as both inducers and inhibitors of CYP1 enzymes, based on the dose, or the differences in active compounds:
- Curcumin at 0.1% of the diet induces this enzyme, yet a diet of 1% turmeric is inhibitory (R).
- Black tea at 54 mL/d induced CYP1A1, yet 20 mg/kg of theaflavins was inhibitory (R).
- Soybean intake at 100 mg/kg increased enzyme activity, yet at 1 g/kg black soybean extract and 200 mg daidzein twice daily was inhibitory (R).