Chronic intake of an enriched diet with spirulina (Arthrospira maxima) alleviates the embryotoxic effects produced by realistic concentrations of tetracycline in Danio rerio

Tetracycline (TC) is one of the most consumed antibiotics worldwide. Due to its high consumption, recent studies have reported its presence in aquatic environments and have assessed its effects on fish, algae, and daphniids. However, in most of those works, authors have tested TC toxicity at concentrations higher than the ones reported in the water matrix. Herein, we aimed to assess the likely embryotoxic and oxidative damage induced by environmentally relevant concentrations of TC in embryos of Danio rerio. Moreover, we seek to determine whether or not an enriched diet with spirulina can alleviate the embryotoxic damage produced by TC. Our findings indicated that TC at concentrations of 50 to 500 ng/L induced pericardial edema, tail deformities, and absence of head and fin in embryos after 96 h of exposure. Moreover, this antibiotic prompted the death of embryos in a concentration-dependent manner. According to our integrated biomarker response index, TC induced oxidative damage on Danio rerio embryos, as star plots showed a tendency to lipoperoxidation, hydroperoxides, and protein carbonyl content. Spirulina reduced the toxicity of TC by diminishing the levels of oxidative damage biomarkers, which resulted in a decrease in the rate of death and malformed embryos. Overall, TC at concentrations of ng/L prompted oxidative stress and embryotoxicity in the early life stages of Danio rerio; nonetheless, the algae spirulina was able to reduce the severity of those effects.

Automated summary

Tetracycline (TC) is a widely consumed antibiotic that has been found in aquatic environments and shown to have toxic effects on various organisms. This study aimed to assess the embryotoxic and oxidative damage caused by environmentally relevant concentrations of TC on Danio rerio embryos. The results showed that TC at concentrations of 50-500 ng/L induced deformities and mortality in the embryos, as well as oxidative damage. However, an enriched diet with spirulina was found to reduce the toxicity of TC and alleviate the observed effects.