Food‐Borne Exposure of Juvenile Rainbow Trout (Oncorhynchus mykiss) to Benzotriazole Ultraviolet Stabilizers Alone and in Mixture Induces Specific Transcriptional Changes

Abstract

Benzotriazole ultraviolet‐stabilizers (BZT‐UVs) are commonly used as additives to protect from light‐induced degradation in a variety of consumer goods. Despite their widespread presence in aquatic ecosystems, information on the effects of these compounds remains largely unknown. The objectives of the present study were to evaluate the chronic effects of 2 BZT‐UVs alone and in a mixture, 2‐(2H‐benzotriazol‐2‐yl)‐4,6‐bis(1‐methyl‐1‐phenylethyl)phenol (UV‐234) and 2‐(2H‐benzotriazol‐2‐yl)‐4,6‐di‐tert‐pentylphenol (UV‐328), in juvenile rainbow trout (Oncorhynchus mykiss) chronically exposed (for 28 d) through the diet. Chemical analyses of livers from exposed trout suggested liver accumulation and potential metabolism of the 2 compounds. Hepatic RNA‐sequencing analyses revealed specific effects of each compound on gene transcription profiles; UV‐234 affected mainly genes involved in cellular metabolism, whereas UV‐328 induced the transcription of ribosomal proteins and downregulated genes involved in immune responses. Both compounds regulated iron homeostasis genes in an opposite manner. The mixture of both BZT‐UVs did not produce significant evidence of additive or synergistic effects. Environ Toxicol Chem 2020;39:852–862. © 2020 Her Majesty the Queen in Right of Canada. Environmental Toxicology and Chemistry © 2020 SETAC

Distribution and Fate of Ultraviolet Absorbents and Industrial Antioxidants in the St. Lawrence River, Quebec, Canada

“…Giraudo et al. 36 reported that the measured half-life was 3.0 days for UV328 and 2.2 days for UV234 in the juvenile rainbow trout ( O. mykiss ), which were much shorter than the EPI modeling results (14 days for UV328 and 13 days for UV234). Thus, these contaminants may be less persistent and bioaccumulative in the SLR compared to the modeling results.…”

“…Giraudo et al . reported that the measured half-life was 3.0 days for UV328 and 2.2 days for UV234 in the juvenile rainbow trout (O.…”

“…Furthermore, recent laboratory exposure studies found that BZT-UVs can be biotransformed relatively quickly and had a short half-life in fish when compared to the Estimation Program Interface (EPI) Suite estimated results. 35 , 36 The whole-body-based bioconcentration factor (BCF) of UV328, for example, was measured to be 490–2080 L/kg in zebrafish ( Danio rerio ), 35 which was lower than the EPI-predicted 6006 L/kg. UV328 had a half-life of about 3 days in juvenile rainbow trout ( Oncorhynchus mykiss ) that are exposed to this contaminant via food, 36 which was much shorter than the 14 days predicted by EPI.…”

“… 35 , 36 The whole-body-based bioconcentration factor (BCF) of UV328, for example, was measured to be 490–2080 L/kg in zebrafish ( Danio rerio ), 35 which was lower than the EPI-predicted 6006 L/kg. UV328 had a half-life of about 3 days in juvenile rainbow trout ( Oncorhynchus mykiss ) that are exposed to this contaminant via food, 36 which was much shorter than the 14 days predicted by EPI. As a result, some of these contaminants may be less bioaccumulative in wild fish than previously thought.…”

Human metabolism and kinetics of the UV absorber 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (UV 328) after oral administration

“…Chronic exposure of fish induced oxidative stress in the liver so that significant effects to antioxidant enzymes as well as tissue damage were reported (Hemalatha et al 2020). Furthermore, accumulation of UV 328 in fish liver was found after chronic food-borne exposure together with transcriptional changes in gene expression (Giraudo et al 2020). Thereby, induced transcription of ribosomal protein was observed together with the downregulation of genes involved in immune responses.…”