Sophorae tonkinensis radix polysaccharide attenuates acetaminophen-induced liver injury by regulating the miR-140-5p-related antioxidant mechanism

STRP1, a polysaccharide active ingredient isolated from the traditional Chinese medicine Sophorae tonkinensis radix, has demonstrated a protective effect against acetaminophen (APAP)-induced liver injury (AILI). The underlying molecular mechanism was investigated in this study. Here, an acute liver damage mouse model was generated by APAP (400 mg/kg) and used to identify the protective effect of STRP1 (200 mg/kg) on mouse livers. In vitro cell experiments were used to further verify the related signaling pathways. Initially, in our study, STRP1 treatment reduced APAP-induced liver injury by decreasing aminotransferase activity and cell apoptosis and increasing cell proliferation. Furthermore, STRP1 treatment significantly increased Nrf2 expression and alleviated oxidative stress caused by reactive oxygen species in AILI. Based on bioinformatics and experimental studies, miR-140-5p was identified and found to be reduced by STRP1, increasing Nrf2 expression. Additionally, Nrf2 played an important role in the protective impact of STRP1-suppressed miR-140-5p expression. Generally, these results showed that STRP1-mediated suppression of miR-140-5p expression mitigates AILI by activating the Nrf2-mediated Nrf2-Keap1 pathway. This study revealed that STRP1 might be a potential treatment agent for AILI.