Adlay is a grass crop which has been used in traditional Chinese medicine and also as a nourishing food. It has been shown to posses anti-allergic, antimutagenic and hypolipemic effects. However, the steroidogenic effects of crude adlay hull acetone extract (AHA) on adrenal zona fasciculata-reticularis (ZFR) cells are still unclear. ZFR cells were incubated with AHA in the presence or absence of 25-hydroxy cholesterol (25-OH-cholesterol), pregnenolone, progesterone or deoxycorticosterone. The concentrations of corticosterone or pregnenolone in the media were measured by radioimmunoassay (RIA). The present data demonstrated that (1) AHA (800μg/ml) caused more pregnenolone release in control group, but not in 25-OH-cholesterol, trilostane or 25-OH-cholesterol+trilostane group; (2) kinetic study showed an uncompetitive inhibition model of AHA to P450 side chain cleavage enzyme (P450scc); (3) kinetic study showed a noncompetitive inhibition model of AHA to 11β-hydroxylase.
