Avermectin reduces bone mineralization via the TGF-β signaling pathway in zebrafish

Abamectin at environmentally relevant concentrations impairs bone development in zebrafish larvae

Abamectin (ABM) is a widely used pesticide in agriculture and veterinary medicine, which primarily acts by disrupting the neurological physiology of pests, leading to their paralysis and death. Its extensive application has resulted in contamination of many natural water bodies. While the adverse effects of ABM on the growth and development of non-target organisms are well documented, its impact on bone development remains inadequately studied. The present study aimed to investigate the effects of environmentally relevant concentrations of ABM (1, 5, 25 μg/L) on early bone development in zebrafish. Our results indicated that ABM significantly affected both cartilage and bone development of zebrafish larvae, accompanied by dose-dependent increase in deformity and mortality rates, as well as exacerbated apoptosis. ABM exposure led to deformities in the ceratobranchial (cb) and hyosymplectic (hs), accompanied by significant increases in the length of the palatoquadrate (pq). Furthermore, significant decreases in the CH-CH angle, Meckel's-Meckel's angle, and Meckel's-PQ angle were noted. Even at the safe concentration of 5 μg/L (1/10 of the 96 h LC50), ABM delayed the process of bone mineralization in zebrafish larvae. Real-time fluorescent quantitative PCR results demonstrated that ABM induced differential gene expression associated with cartilage and bone development in zebrafish. Thus, this study provides preliminary insights into the effects and molecular mechanisms underlying ABM's impact on the bone development of zebrafish larvae and offers new evidence for a better understanding of its toxicity.

Citrus reticulata peel extract mitigates oxidative stress and liver injury induced by abamectin in rats

The prevalent use of abamectin (ABM) has latterly raised safety attention as it has different toxicities to non-target living organisms. Citrus fruits are widely renowned for their nutritional and health-promoting qualities, and their peels are full of phenolic constituents. The purpose of the current study was to evaluate the modulatory effectiveness of Citrus reticulata peel extract (CPE) against abamectin-induced hepatotoxicity and oxidative injury. Rats were distributed into 4 groups as follows: control, CPE (400 mg/kg bw orally for 14 days), ABM (2 mg/kg bw for 5 days), and CPE + ABM at the doses mentioned above. Results revealed that GC-MS analysis of CPE has 19 identified components with significant total phenolic and flavonoid contents. Treatment with ABM in rats displayed significant variations in enzymatic and non-enzymatic antioxidants, oxidative stress markers (MDA, H2O2, PCC), liver and kidney function biomarkers, hematological parameters, lipids, and protein profile as well as histopathological abnormalities, inflammation and apoptosis (TNF-α, Caspase-3, NF-κB, and Bcl-2 genes) in rats' liver. Supplementation of CPE solo dramatically improved the antioxidant state and reduced oxidative stress. C. reticulata peel extract pretreatment alleviated ABM toxicity by modulating most of the tested parameters compared to the ABM group. Conclusively, CPE had potent antioxidant activity and could be used in the modulation of ABM hepatotoxicity presumably due to its antioxidant, anti-inflammatory, and gene-regulating capabilities.