Sister chromatid exchange test in river buffalo lymphocytes treated in vitro with furocoumarin extracts

Furocoumarin extracts from Psoralea morisiana, the endemic Sardinian legume species, were
tested for their mutagenic potential on river buffalo blood cells. The results obtained performing
the sister chromatid exchange (SCE) test in blood cultures of five river buffalo calves (exposure
to furocoumarins for 72 h) and five cows (exposure to furocoumarins for 3 h, in the absence and
presence of S9 metabolic activator) are reported. Significant differences in mean values of SCEs
were observed in cells of calves compared to control cells (unexposed), but no differences in
SCE mean values were found between treated and untreated cells of cows in the presence or
absence of S9. SCE mean values were much higher in cells of cows (exposed and control) than
in cells of calves. Indeed, in calf cells, SCE mean values/cell (±SD) were 6.66 ± 2.45 in the control
and 7.63 ± 3.01, 9.03 ± 3.90, 9.53 ± 3.60 and 9.99 ± 3.41 in treated cells at 50, 100, 200 and 400 μg/ml
of furocoumarin extracts, respectively. In cow cells, grown in presence of S9, SCE mean values/
cell were 11.49 ± 4.78 and 11.65 ± 5.19 in treated cells at 100 and 200 μg/ml of furocoumarins
and 11.66 ± 5.45 in the control. In cow cells grown in absence of S9, SCE mean values were
11.81 ± 6.14 in the control and 12.35 ± 7.09 and 12.01 ± 5.43, respectively, in the presence of 100
and 200 μg/ml of furocoumarins. Despite their higher SCE values in the absence of S9, no
statistically significant differences were found when these values were compared with those
shown in presence of S9, suggesting no mutagenic action of furocoumarins in cows, at the
doses used in this study.