Low folate status increases chromosomal damage by X-ray irradiation

Area of Science:

• Radiobiology
• Nutritional Biochemistry

Background:

• Folate is essential for DNA synthesis and repair.
• Chromosomal damage can result from ionizing radiation exposure.

Purpose of the Study:

• To investigate the impact of folate status on chromosomal damage induced by X-ray irradiation.
• To determine if folic acid supplementation provides protection against radiation-induced DNA damage.

Main Methods:

• Animal study: Mice fed varying folic acid diets (0, 2, 40 mg/kg) received total body irradiation (TBI).
• Human study: Subjects supplemented with folic acid (800 μg/day) had peripheral blood irradiated in vitro.
• Chromosomal damage assessed using the micronucleus assay.

Main Results:

• In mice, low folate diet led to higher chromosomal damage and lower bone marrow folate post-TBI.
• Folate levels decreased in mouse plasma, erythrocytes, and bone marrow after TBI.
• In humans, folic acid supplementation increased plasma folate but did not alter radiation-induced chromosomal damage in lymphocytes.

Conclusions:

• A deficiency in folate increases vulnerability to X-ray-induced chromosomal damage.
• Excessive folic acid supplementation does not enhance protection beyond saturation levels in target tissues.