Naturally occurring depsidones from the marine fungus Aspergillus unguis are known to have substantial anti-
cancer activity, but their mechanism of action remains elusive. The purpose of this study was to examine the anti-
aromatase activity of two common depsidones,
unguinol and
aspergillusidone A, in a co-culture system of human primary breast adipose fibroblasts and hormonal responsive T47D
breast tumor cells. Using this in vitro model it was shown that these depsidones inhibit the growth of T47D
tumor cells most likely via inhibition of
aromatase (
CYP19) activity. The IC50 values of these depisidones were compared with the
aromatase inhibitors letrozole and
exemestane.
Letrozole and
exemestane had IC50 values of respectively, 0.19 and 0.14 μM, while those for
Unguinol and
Aspergillusidone A were respectively, 9.7 and 7.3 μM. Our results indicate that among the depsidones there maybe
aromatase inhibitors with possible pharmacotherapeutical relevance.