Interaction of Thalassia testudinum Metabolites with Cytochrome P450 Enzymes and Its Effects on Benzo(a)pyrene-Induced Mutagenicity

Abstract

The aim of the present work was to evaluate the effects of Thalassia testudinum hydroethanolic extract, its polyphenolic fraction, and thalassiolin B on the activity of phase I metabolizing enzymes as well as their antimutagenic effects. Spectrofluorometric techniques were used to evaluate the effect of tested products on rat and human CYP1A and CYP2B activity. The antimutagenic effect of tested products was evaluated in benzo[a]pyrene (BP)-induced mutagenicity assay by Ames test. Finally, the antimutagenic effect of Thalassia testudinum (100 mg/kg) was assessed in a BP-induced mutagenesis in mice. The tested products significantly (p<0.05) inhibit rat CYP1A1 activity, acting as mixed-type inhibitors of rat CYP1A1 (Ki = 54.16±9.09 μg/mL, 5.96±1.55 μg/mL and 3.05±0.89 μg/mL, respectively). Inhibition of human CYP1A1 was also observed (Ki = 197.1±63.40 μg/mL and 203.10±17.29 μg/mL for the polyphenolic fraction and for thalassiolin B, respectively). In addition, the evaluated products significantly inhibit (p<0.05) benzo[a]pyrene (BP)-induced mutagenicity in vitro. Furthermore, oral doses of Thalassia testudinum (100 mg/kg) significantly reduced (p<0.05) the BP-induced micronuclei and oxidative damage, together with an increase of glutathione, in mice. In summary, Thalassia testudinum metabolites exhibit antigenotoxic activity mediated, at least, by the inhibition of CYP1A1-mediated BP biotransformation. Thus, the metabolites of T. testudinum may represent a potential source of chemopreventive compounds for adjuvant therapy of cancer.

Marine Compounds and Cancer: Updates 2020

“…Finally, Delgado-Roche et al reported that metabolites of Thalassia testudinum , in particular thalassiolin B , exhibit chemopreventive and antigenotoxic activity, which can be of use in anticancer therapy. This effect was at least partially mediated by the inhibition of the CYP1A1-mediated benzo[a]pyrene-induced transformation (i.e., by suppressing the effects of oxidative and mutagenic stress) [ 40 ].…”