A multibiomarker approach to assess the effects of a BPA analogue-contaminated diet in the crab Carcinus aestuarii

Bisphenol A analogues are largely used plasticisers that are going to replace bisphenol A in many sectors. Due to this replacement, their discharge and presence in the marine coastal areas are increasing, with unknown consequences for organisms and the trophic chain. This study assessed the effects of three different bisphenols (BPAF, BPF and BPS) - alone or as a mixture - provided via food (exposed clams) to the crab Carcinus aestuarii. First, clams were exposed for two weeks to 300 ng/L of each of the three bisphenols and their mixture (100 ng/L of each) to allow the bioaccumulation of the contaminants in bivalves. Then, crabs were fed for two weeks with BPA analogue-exposed clams, while unexposed clams were used to feed control crabs. After 7 and 14 days, haemolymph, gills and hepatopancreas were collected from crabs to measure a battery of biomarkers indicative of cytotoxicity, oxidative stress and damage, neurotoxicity, physiological performance (respiration and excretion rate) and electron transport system activity. Lastly, bioaccumulation of BPA analogues was assessed by UHPLC-HRMS in crabs. Our findings revealed that BPA analogue-exposed clams were able to alter total haemocyte count, haemocyte size and their proliferation. The activity of immune enzymes, such as phosphatases and phenoloxidase was altered. Moreover, we observed an impairment of antioxidant and detoxifying enzymes like SOD, CAT, GST and GPX activities. Alterations of metabolism-involved enzymes and physiological parameters and increased oxidative damage to macromolecules like proteins, lipids, and DNA were also observed in crabs. Among BPA analogues, only bioaccumulation of BPAF, which has the highest Log_kow value among the tested bisphenols, was evidenced in crabs. Overall, the obtained results indicated that crabs, under the tested experimental conditions at least, underwent alterations in cellular, biochemical and physiological responses following a diet of bisphenol-exposed clams, suggesting a potential ecotoxicological risk in the marine food chain.