Evaluation of the Oxidative Stress Status in Zebrafish (Danio rerio) Liver Induced by Three Typical Organic UV Filters (BP-4, PABA and PBSA)

Abstract

Organic UV filters are a kind of emerging pollutants, which have been widely used in personal care products (PCPs). This study evaluated the effects of benzophenone-4 (BP-4), 4-aminobenzoic acid (PABA), and 2-phenylbenzimidazole-5-sulfonic acid (PBSA) on the selected indices of antioxidative responses in zebrafish (Danio rerio) liver. Zebrafish were exposed to two different doses (i.e., 0.5 and 5 mg L^-1) of semi-static water with three individual compounds. Liver samples were collected on 7 and 14 days to analyze biochemical indicators, including superoxide dismutase (SOD), glutathione S-transferase (GST), reduced glutathione (GSH), and malondialdehyde (MDA). Oxidative stress occurred in zebrafish liver with significantly changed indicators during the whole exposure period. Different experimental groups could induce or inhibit the activity of antioxidant enzymes with varying degrees. With a prolonged exposure time and increased exposure dose, the hepatic lipid peroxidation was also obviously observed. Moreover, the toxicity order of three organic UV filters was analyzed using the integrated biomarker response (IBR) index and the results indicate that exposure to PABA for 7 days at 0.5 mg L^-1 and PBSA for 7 days at 5 mg L^-1 induced the most severe oxidative stress in the liver of zebrafish.

Keywords: integrated biomarker response; lipid peroxidation; organic UV filters; oxidative stress; zebrafish.

Figure 1

The testing procedures for oxidative stress evaluation of BP-4, PABA, and PBSA in zebrafish liver.

Figure 2

Effect of exposure to BP-4, PABA, or PBSA (0.5 and 5 mg L⁻¹) for 7 and 14 days on the activity of biochemical indicators (A, SOD; B, GST; C, CSH; D, MDA) in zebrafish liver. Data are expressed as means ± SD, n = 3 for each data point. Superscript letters a–e indicate differences among the experimental treatments at the same exposure time. * Significantly different from controls (p < 0.05), ** Highly significantly different from controls (p < 0.01).

Figure 3

Biomarker star plots (A) and the calculated IBR values (B) of all biochemical parameters measured in zebrafish liver after exposure to BP-4, PABA, or PBSA (0.5 and 5 mg L⁻¹) for 7 and 14 days.