Myricetin Modulates Redox Balance in MDBK Cells in a Dose-Dependent Manner

Abstract

Myricetin (MYR), a natural flavonoid, exerts antioxidant effects by scavenging free radicals and enhancing cellular defenses. However, its dose-dependent redox-regulatory effects in Madin-Darby bovine kidney (MDBK) cells remain unexplored. This study aimed to investigate the dose-dependent effects of myricetin on redox balance in MDBK cells by measuring total antioxidant capacity (TAC) and total oxidant capacity (TOC). MYR was dissolved in 0.1% DMSO. Cells were treated for 24 hours in quadruplicate, with untreated cells as the negative control (NC) and 0.1% DMSO as the vehicle control. Cell viability was assessed by MTT assay, confirming that MYR treatments maintained >95% cell survival. TAC and TOC levels were measured using a commercial spectrophotometric kit, and each measurement was carried out in duplicate. Oxidative stress index (OSI) was calculated as the ratio of TOC to TAC. Statistical analysis was performed using one-way ANOVA followed by Tukey’s post hoc test, with p<0.05 considered significant. TAC levels (mmol Trolox equivalent/L) increased from 1.07±0.03 in the NC group to 1.29±0.07 with MYR 10 μM (p=0.008), 1.52±0.07 with MYR 50 μM (p<0.01), and 1.73±0.12 with MYR 100 μM (p<0.01). Conversely, TOC levels (μmol H₂O₂ equivalent/L) decreased from 10.19±0.28 in NC to 8.02±0.17 with MYR 10 μM (p<0.01), 7.33±0.17 with MYR 50 μM (p<0.01), and 6.09±0.11 with MYR 100 μM (p<0.01). The 0.1% DMSO control did not significantly alter TAC (1.16±0.06, p>0.05 vs NC) but caused a slight decrease in TOC (9.50±0.18, p>0.05 vs NC). These results indicate that myricetin modulates oxidative balance in a dose-dependent manner. In conclusion, MYR significantly increased antioxidant capacity and reduced oxidative stress in MDBK cells in a dose-dependent manner. The dose-dependent decrease in OSI values indicates a shift towards redox balance. These findings, which reveal the cellular redox regulatory potential of MYR, are expected to contribute to the understanding of flavonoid-mediated antioxidant mechanisms in veterinary and cell biology research, as well as in nutraceutical studies as a feed supplement.