Effects of Hypericum perforatum extract and its main bioactive compounds on the cytotoxicity and expression of CYP1A2 and CYP2D6 in hepatic cells.

AIMS: Hypericum perforatum (H. perforatum) is one of the most used medicinal plants. However, it has been associated with relevant interactions with several drugs. This situation is probably mediated by cytochrome P450 enzymes (CYP450), namely the 1A2 (CYP1A2) and 2D6 (CYP2D6) isoforms This study aims to assess the cytotoxic and CYP1A2 and CYP2D6 inductive and/or inhibitory effects of a H. perforatum extract and its main bioactive components in hepatic cell lines. MAIN METHODS: A MTT proliferation assay was performed in WRL-68, HepG2 and HepaRG cells after exposition to different concentrations of H. perforatum extract, hypericin and hyperforin for 24 and 72 h. Then, a real-time PCR analysis was accomplished after incubating the cells with these products evaluating the relative CYP1A2 and CYP2D6 expression. KEY FINDINGS: These products have relevant cytotoxicity at a 10 µM concentration and it was also demonstrated for the first time that H. perforatum can lead to a significant CYP1A2 and CYP2D6 induction in all cell lines. Moreover, hypericin seems to induce CYP1A2 in HepG2 cells and to inhibit its expression in HepaRG cells while hyperforin induced CYP1A2 in HepG2 and in WRL-68 cells. Additionally, hypericin and hyperforin induce CYP2D6 in HepG2 cells but inhibits its expression in HepaRG and in WRL-68 cells. SIGNIFICANCE: This study not only evidenced that H. perforatum extract and two of its bioactive components can have toxic effects in hepatic cell lines but also emphasized the potential risk of the consumption of H. perforatum with CYP1A2- and CYP2D6-metabolized drugs.

Cytotoxic Effects of Salvinorin A, A Major Constituent of Salvia divinorum.

S. divinorum is a psychoactive plant that has been consumed as a recreational drug of abuse in the last years. Salvinorin A is its main constituent, and is responsible for the observed psychoactive effects. Both S. divinorum and salvinorin A have become controlled drugs in several countries, but they are not listed in the Schedules of the United Nations Drug Conventions. Regarding the effects of S. divinorum consumption, almost all studies are based on in vivo or on surveys, and there are no studies in vitro on its toxicity. Furthermore, all studies are focused on the acute toxicological effects of the plant. So, it is of utmost importance to further investigate the effects of S. divinorum and salvinorin A, particularly using in vitro models, after prolonged exposures. In this context, the present work evaluated the in vitro toxicity induced by S. divinorum or salvinorin A in six cell lines, through MTT assays and LC50 determination. Overall, results showed that both S. divinorum and salvinorin A are cytotoxic, dose- and time-dependent. Also, Hep G2 and Caco 2 (to a lesser extent) cells showed lower sensitivity to S. divinorum and salvinorin A when compared to the other studied cell lines. To our knowledge, this is the first work focused on the in vitro toxicity of S. divinorum and salvinorin A using a variety of cell lines, which are extensively described in literature and have been widely used in several in vitro studies.