Effects of alisol B 23-acetate on water-liquid balance in mice with senecionine-induced acute liver injury

Misuse of pyrrolizidine alkaloid (PA)-containing herbs is the major cause of hepatic sinusoidal obstruction syndrome (HSOS) in China. And diuretics are among the most commonly used medications for the treatment of PA-induced HSOS in clinical practice. As a traditional diuretic in traditional Chinese medicine, the diuretic mechanism of Alismatis Rhizoma (AR) has not been fully clarified, and there is no report on AR ameliorating PA-induced HSOS from a diuretic point of view. Therefore, this study aims to investigate the therapeutic potential of alisol B 23-acetate (AB23A) against acute liver injury induced by senecionine (a representative toxic PA) in mice, and to further elucidate its effect on impaired water-liquid balance in mice exposed to PA. All experiments were approved by the Animal Research Committee of Shanghai University of Traditional Chinese Medicine (Registration number: PZSHUTCM220808017). Animal welfare and the animal experimental protocols were strictly consistent with related ethics regulations of Shanghai University of Traditional Chinese Medicine. Model of mice was induced by a single oral exposure of senecioine (50 mg·kg^-1) (SEN group), and AB23A (40 mg·kg^-1) intervention group (AB23A+SEN group), solvent control group (Ctrl group) and AB23A control group (AB23A group) were set up. The results showed that AB23A could significantly attenuate the levels of serum biochemical indices of liver functions in senecioine-induced acute liver injury mice, as evident by alleviated hepatocyte necrosis and hepatic sinusoidal stasis. AB23A also improved kidney function of mice exposed to senecionine, fascinated urinary excretion and repaired electrolyte disorders, as well as decreased content of senecioine metabolites. Further, the protein and mRNA expression of genes related to the water balance pathway were measured. AB23A could significantly down-regulate the elevated protein and mRNA expression levels of aquaporin 2 (AQP2) and angiotensin Ⅱ type 1 receptor, and inhibit the transport of AQP2 to the apical plasma membrane induced by senecionine exposure. AB23A also significantly decreased serum levels of angiotensin Ⅱ. In vitro studies further confirmed that AB23A regulates AQP2 expression in renal inner medullary collecting duct cells 3 (IMCD3). These data indicate that AB23A regulates the expression of AQP2 in renal medulla, thereby affecting its water reabsorption in mice with senecionine-induced acute liver injury. This work achieves a better understanding of the diuretic effect of AR, and provides experimental foundation and theoretical basis for the treatment of PA-induced acute liver injury by AR in clinics.