Quercetin Mitigates Oxidative Stress, Developmental Toxicity and Teratogenic Effects Induced by High-dose Vitamin D2 in Zebrafish Embryos

The aim of the study was to determine the developmental toxicity of high-dose administration of vitamin D-2 (vit. D-2) and the synergistic effect of vit. D-2 in co-treatment with quercetin. Zebrafish embryos at 6 hpf were treated with either vit. D-2 (1, 5, 10 mu g/mL) or quercetin (5, 10 mu g/mL) alone. The results from visual assessment and morphological feature scoring revealed, the occurrence of different morphological abnormalities spiked and aggravated with an increase in vit. D-2 dose. The percentage of hatching, heartbeats/minute, velocity, body length, and survivability rate was downregulated in high dose vit. D-2 groups. Subsequently, the production of pro-inflammatory cytokines and intracellular ROS was upregulated in high-dose vit. D-2 groups. Contrastingly, in the co-treatment of vit. D-2 (5 mu g/mL) and quercetin (1, 5, 10 mu g/mL), the occurrence of abnormal morphological characteristics was downregulated and the percentage of survivability rate was significantly increased. The production of inflammatory cytokines, intracellular ROS, and MDA was also observed to be inhibited in co-treatment groups. The important antioxidants such as glutathione and catalase were increased in co-treatment groups. The activity of S-A-beta gal and apoptosis was downregulated in co-treatment groups. Collectively, quercetin ameliorated the developmental toxicity and teratogenic effects induced by high-dose vit. D-2.