The administration of Glycyrrhiza polysaccharides mitigates liver injury in mice caused by mancozeb via the Keap1-Nrf2/NF-κB pathway.

The extensive utilization of mancozeb (MCZ) poses environmental pollution risks, threatens human health, particularly hepatotoxicity. Glycyrrhiza polysaccharides (GP) exhibit antioxidant, anti-inflammatory and other biological activities. The aim of this study is to explore the mechanism of liver injury in mice exposed to MCZ and the protective effect of GP on alleviating MCZ induced liver injury. Initially, 70 female mice were divided into 7 groups, and the optimal dose of MCZ induced liver injury in mice was screened by oral administration different doses of MCZ (0, 50, 100, 150, 200, 250 and 300 mg/kg MCZ). The results demonstrated that, compared to the blank control group, as the concentration of MCZ increased, several physiological and biochemical parameters were significantly affected. Specifically, body weight and liver index significantly decreased, while the activities of SOD and CAT also decreased. Additionally, the content of ROS increased, the levels of Keap1 and Nrf2 proteins increased, the mRNA levels of Gpx2 and HO-1decreased, and the mRNA levels of Gstt2, GcLc and NQO1 were upregulated. Based on the test data, select 100 mg/kg MCZ as the optimal modeling dose for experimental animals. Sixty female mice were divided into six groups and orally administered: control group A (0.2 mL deionized water), model group B (100 mg/kg MCZ), positive control group F (100 mg/kg MCZ+100 mg/kg VC), the high-dose GP group C (100mg/kgMCZ+200mg/kgGP), the medium-dose GP group D (100 mg/kg MCZ+150mg/kgGP) and the low-dose GP group E (100 mg/kg MCZ+100mg/kgGP). The results showed that compared to the model group, adding GP alleviated the effects of MCZ on body weight, liver index, CAT and SOD activity, MDA content, HO-1, TNF-α, and IL-1β. Additionally, the addition of GP decreased the expression of Keap1, Nrf2, NF-kB, and NQO1, GcLc, and Gstt2 mRNA. GP ameliorated liver vacuolar degeneration, steatosis and nuclear pyknosis ameliorate by MCZ. The results show that MCZ triggers hepatotoxicity via the activation of the Keap1/Nrf2 signaling pathway, whereas GP has the potential to mitigate liver damage caused by MCZ exposure by inhibiting this pathway.