Protective effects of roselle (<i>Hibiscus sabdariffa</i>) aqueous extract against aristolochic acid-induced developmental nephrotoxicity in zebrafish

This study investigates the protective effects of roselle aqueous extract (RAE) against aristolochic acid (AA)-induced developmental nephrotoxicity in zebrafish embryos. Fluorescence imaging, immunohistochemistry, and real-time polymerase chain reaction (PCR) experiments were conducted. The results showed that pre-treatment with RAE significantly improved survival rates and reduced kidney malformations in AA-exposed zebrafish. Specifically, survival rates in the AA-treated group decreased to 81.11% by 72 hours post-fertilisation, whereas those in the AA+RAE (30 and 60 ppm) groups increased to 86.67-90%. Additionally, RAE pre-treatment reduced kidney malformation rates from 98.89% in the AA group to 75.56% and 63.33% in the AA+RAE (30 and 60 ppm) groups, respectively. Histological analysis revealed that RAE mitigated structural damage in the pronephric tubes, restoring their compact architecture. Molecular analysis using real-time reverse transcription (RT)-PCR further indicated that RAE reduced the expression of inflammatory markers, suggesting that its protective effects are mediated through the attenuation of AA-induced inflammation. These findings demonstrate that RAE exerts a protective role against AA-induced developmental kidney malformations in zebrafish, likely through its antioxidant and anti-inflammatory properties.