# Study on the Protective Mechanism of Dihydromyricetin Against Aflatoxin B1-Induced Injury in Madin–Darby Canine Kidney Cells

## TL;DR

This study shows that dihydromyricetin protects kidney cells in dogs from aflatoxin B1 damage by reducing inflammation and boosting cell repair.

## Contribution

The study reveals a novel protective mechanism of dihydromyricetin against aflatoxin B1-induced kidney cell injury in dogs.

## Key findings

- DMY reduces AFB1-induced oxidative stress and inflammation in MDCK cells.
- DMY promotes autophagy by modulating key proteins like p-AMPK and Beclin-1.
- 25 mmol/L and 50 mmol/L DMY concentrations showed optimal protective effects.

## Abstract

Aflatoxin B1 (AFB1) is a common contaminant in canine diets that can cause significant damage to metabolic organs with prolonged exposure. Dihydromyricetin (DMY), a flavonoid compound abundant in Ampelopsis grossedentata, is widely used in functional foods due to its diverse biological activities. This study aimed to investigate the mechanism by which DMY alleviates AFB1-induced damage in MDCK cells. Four experimental groups were established: a control group with culture medium only (CON group), a group treated with 5 μg/mL AFB1 (AFB1 group), and two treatment groups treated with 5 μg/mL AFB1 combined with either 25 mmol/L or 50 mmol/L DMY—concentrations with more robust and stable protective effects than 100 mmol/L DMY, as confirmed by experimental screening. The results showed that AFB1 significantly reduced MDCK cell viability at concentrations of 5–30 μg/mL (p < 0.01), while DMY at 25–100 mmol/L markedly improved cell viability (p < 0.01). AFB1 treatment led to a significant increase in reactive oxygen species (ROS), malondialdehyde (MDA), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) levels, along with a reduction in superoxide dismutase (SOD) and catalase (CAT) activities (p < 0.01). 25 mmol/L and 50 mmol/L DMY treatment reversed these effects, decreasing ROS, MDA, TNF-α, IL-6, and IL-1β levels while increasing SOD and CAT activities (p < 0.01). Furthermore, 25 mmol/L and 50 mmol/L DMY improved mitochondrial membrane potential (p < 0.01), counteracting AFB1’s inhibitory effects on autophagy-related proteins by promoting p-AMPK and Beclin-1 expression while inhibiting p-mTOR, p53, and p62 expression (p < 0.05). In conclusion, DMY mitigates AFB1-induced damage in MDCK cells by enhancing anti-inflammatory and antioxidant defenses and promoting autophagy, providing a theoretical foundation for future treatment strategies for canine kidney damage.