Chromosomal aberrations and sister chromatid exchanges in lymphocytes and urine mutagenicity of migraine patients: a comparison of chronic feverfew users and matched non-users.

1. Thirty migraine patients who had taken the leaves, tablets or capsules of feverfew daily for more than 11 consecutive months were compared to 30 feverfew non-user migraine patients who had been individually age- and sex-matched. 2. The frequency of chromosomal aberrations and sister chromatid exchanges (SCE) were determined from lymphocyte cultures established from blood samples taken over a period of several months. Matched pairs were sampled on the same date for two-thirds of the cases, and the greatest difference in sampling time of the remainder was 20 days. Also, the mutagenicity of urine samples from 10 feverfew user migraine patients was compared to that from 10 matched non-user migraine patients using the Ames Salmonella mutagenicity test system. Paired samples were given on the same date. 3. The mean frequency of chromosomal aberrations in the feverfew user group was lower than that in the non-user group both in terms of cells with breaks (2.13% vs 2.76%) and in terms of cells with all aberrations (4.34% vs 5.11%). However, this difference was small and not significant. 4. The mean frequency of SCE in the feverfew exposed group was lower than that in the control group (8.78 vs 8.80 SCE/cell), but, this difference was not significant as determined by factorial analysis of variance (P = 0.897). There was a highly significant variance between the frequencies of SCE in the matched pairs of migraine patients but this was not related to age, sex or feverfew exposure.(ABSTRACT TRUNCATED AT 250 WORDS)