In Vitro Chemopreventive Potential of Phlorotannins-Rich Extract from Brown Algae by Inhibition of Benzo[a]pyrene-Induced P2X7 Activation and Toxic Effects.

Mélody Dutot,Karim Hammad,Elodie Olivier,Emmanuel Roulland,Sophie Fouyet,Roxane Fagon,Patrice Rat,Romain Magny

doi:10.3390/md19010034

Abstract

Phlorotannins are polyphenols occurring exclusively in some species of brown algae, known for numerous biological activities, e.g., antioxidant, antiproliferative, antidiabetic, and antiallergic properties. Their effects on the response of human lung cells to benzo[a]pyrene (B[a]P) has not been characterized. Our objective was to in vitro evaluate the effects of a phlorotannin-rich extract obtained from the brown algae Ascophyllum nodosum and Fucus vesiculosus on B[a]P cytotoxic effects. The A549 cell line was incubated with B[a]P for 48 and 72 h in the presence or absence of the brown algae extract. Cytochrome P450 activity, activation of P2X7 receptor, F-actin disorganization, and loss of E-cadherin expression were assessed using microplate cytometry and fluorescence microscopy. Relative to control, incubation with the brown algae extract was associated with lower B[a]P-induced CYP1 activity, lower P2X7 receptor activation, and lower reactive oxygen species production. The brown algae extract inhibited the alterations of F-actin arrangement and the downregulation of E-cadherin expression. We identified a phlorotannins-rich extract that could be deeper investigated as a cancer chemopreventive agent to block B[a]P-mediated carcinogenesis.

Highlights

The effects of the brown algae extract on B[a]P activation of the cytochrome P450 enzyme system were evaluated by assessment of ethoxyresorufin-O-deethylase (EROD)
Activity in A549 cells supplemented with the brown algae extract at 0.1% (Figure 1)
Since cancer cell migration and metastasis requires reorganization of the cytoskeleton leading to epithelial-mesenchymal transition (EMT) [25], we addressed whether the brown algae extract could prevent B[a]P-induced reorganization of the components of the cytoskeleton

Summary

Introduction

Because PAHs exist naturally in the environment and are man-made, exposure occurs in a number of ways. Big cities around the world face severe atmospheric pollution problems, which directly affects the population’s health. In this context, sixteen PAHs are regulated by the U.S Environmental Protection Agency (USEPA) based on their potential human and ecological health effects. As one of the most common ways B[a]P can enter the human body is through breathing contaminated air, B[a]P is responsible for many respiratory disorders, such as lung cancer and asthma [3,4], and can aggravate allergic rhinitis [5]

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