Effects of the natural bromo-phenol, lanosol, on the expression and activities of various phase I and phase II enzymes from the digestive gland of the gumboot chiton, Cryptochiton stelleri

Lanosol, found in the alga Odonthalia dentata, was administered to gumboot chitons (Chryptochiton stelleri) by oral gavage at 0, 1, 2.5, 5, or 10 mg/kg for 4 days. C. stelleri feed on O. dentata, an alga avoided by most other herbivores. Digestive gland microsomes were probed for expression of various cytochrome P450s. CYP1A and CYP2-like protein expression was not detected in any individual (n=22). Expression of a CYP3A-like protein was increased approximately 30% at higher doses. Estradiol hydroxylase activity increased with increasing dose, while testosterone hydroxylase activity declined with increasing dose. Anti-mammalian glutathione-S-transferase (GST) antibodies did not recognize any cytosolic chiton proteins. CDNB activity was highly variable and showed no relationship to lanosol dose. Lanosol non-competitively inhibited CDNB activity in digestive gland cytosol (IC50=222 μM). This alteration of expression and activity of some Phase I and II biotransformation enzymes by lanosol may provide a selective advantage for chitons feeding on O. dentata.