Safety Assessment of Selenium-Biofortified Broccoli Seedlings: Insights from Repeated-Dose Toxicity and Genotoxicity Evaluation in Mice

Abstract

Selenium (Se) is an essential trace element; however, excessive exposure may cause adverse effects because of its narrow safety margin. This study evaluated the toxicological and genotoxic effects of Se-biofortified broccoli seedlings in male and female Swiss mice. Animals received control or Se-enriched broccoli seedlings orally for 40 days (15, 45, or 70 µg Se/kg body weight (BW)). General toxicity (body weight gain), hematological (complete blood count), biochemical (creatinine, bilirubin, aspartate aminotransferase, alanine aminotransferase, and urea), histopathological, and micronucleus evaluations were performed. No significant changes in body weight or hematological parameters were detected. Biochemical alterations were restricted to males, with increased urea (51.90 ± 2.14 mg/dL) and decreased aspartate aminotransferase (128.4 ± 14.45 U/L) after 45 µg Se/kg BW. The highest Se dose increased spleen (0.60 ± 0.04 g/100 g BW) and ovary (0.29 ± 0.03 g/100 g BW) weights in females, decreased liver weight (5.82 ± 0.10 g/100 g BW), increased testis weight (0.76 ± 0.04 g/100 g BW) in males, induced renal and splenic histological alterations, and increased micronucleated polychromatic erythrocytes (0.46 ± 0.04). These findings indicate that 15 µg Se/kg BW was the safest dose evaluated. Future studies should investigate Se speciation and sex-dependent toxicological responses.