Nuclear abnormalities in buccal mucosa cells of patients with type I and II diabetes treated with folic acid

•Nuclear abnormalities frequency was higher in diabetic patients than in controls.•No differences between type of diabetes, control, smoking, age or sex was observed.•Uncontrolled diabetic patients showed a greater frequency of micronuclei.•Nuclear abnormalities diminish after folic acid intake in diabetic patients.•Folate decreases frequencies of cells with MN, BN, PYK, KR, KR+CC, KL, and NBUD. Diabetes mellitus (DM) is characterized by high blood glucose. Excessive production of free radicals may cause oxidative damage to DNA and other molecules, leading to complications of the disease. It may be possible to delay or reduce such damage by administration of antioxidants such as folic acid (FA). The objective of this study was to determine the effect of FA on nuclear abnormalities (NAs) in the oral mucosa of patients with DM. NAs (micronucleated cells, binucleated cells, pyknotic nuclei, karyorrhexis, karyolysis, abnormally condensed chromatin, and nuclear buds) were analyzed in 2000 cells from 45 healthy individuals (control group) and 55 patients with controlled or uncontrolled type I or II DM; 35 patients in the latter group were treated with FA. Samples were taken from the FA group before and after treatment. An increased rate of NAs was found in patients with DM in comparison with that of the control group (P