The concurrent exposure to aluminium and fructose induces liver injury in rats: Protection by monoammonium glycyrrhizinate

Glycyrrhizin and the Related Preparations: An Inspiring Resource for the Treatment of Liver Diseases

Liver diseases and their related complications endanger the health of millions of people worldwide. The prevention and treatment of liver diseases are still serious challenges both in China and globally. With the improvement of living standards, the prevalence of metabolic liver diseases, including non-alcoholic fatty liver disease and alcoholic liver disease, has increased at an alarming rate, resulting in more cases of end-stage liver disease. Therefore, the discovery of novel therapeutic drugs for the treatment of liver diseases is urgently needed. Glycyrrhizin (GL), a triterpene glycoside from the roots of licorice plants, possesses a wide range of pharmacological and biological activities. Currently, GL preparations (GLPs) have certain advantages in the treatment of liver diseases, with good clinical effects and fewer adverse reactions, and have shown broad application prospects through multitargeting therapeutic mechanisms, including antisteatotic, anti-oxidative stress, anti-inflammatory, immunoregulatory, antifibrotic, anticancer, and drug interaction activities. This review summarizes the currently known biological activities of GLPs and their medical applications in the treatment of liver diseases, and highlights the potential of these preparations as promising therapeutic options and their alluring prospects for the treatment of liver diseases.

Silymarin Protects against Acute Liver Injury Induced by Acetaminophen by Downregulating the Expression and Activity of the CYP2E1 Enzyme

Previous studies have shown that silymarin protects against various types of drug-induced liver injury, but whether the protective mechanism of silymarin against acetaminophen-induced liver injury is related to the CYP2E1 enzyme remains unclear. In this study, we investigated the effect of silymarin on the activity and expression of CYP2E1 in vitro and in vivo. The results of in vitro studies showed that silymarin not only inhibited the activity of CYP2E1 in human and rat liver microsomes but also reduced the expression of CYP2E1 in HepG2 cells. In vivo studies showed that silymarin pretreatment significantly reduced the conversion of chlorzoxazone to its metabolite 6-OH-CLX and significantly increased the t1/2, area under the curve (AUC) and mean residence time (MRT) of chlorzoxazone. In addition, silymarin pretreatment significantly inhibited the upregulation of Cyp2e1 expression, reduced the production of 3-cysteinylacetaminophen trifluoroacetic acid salt (APAP-CYS), and restored the liver glutathione level. The results of our study show that silymarin plays an important protective role in the early stage of acetaminophen-induced acute liver injury by reducing the activity and expression of CYP2E1, reducing the generation of toxic metabolites, and alleviating liver injury.

The renoprotective effect of glycyrrhizic acid in insulin-resistant rats exposed to aluminum involves the inhibition of TLR4/NF-κB signaling pathway

Aluminum is well recognized as a nephrotoxic agent. Its hazardous effects arise from the high risk of daily exposure. The consumption of fructose also represents a critical health issue that might negatively impact different organs, including the kidneys. To pursue our previous work, this study aimed to investigate the potential renoprotective effects of glycyrrhizic acid (GLYA) on aluminum-induced nephrotoxicity in insulin-resistant rats. Insulin resistance (IR) was induced by adding fructose (10%) in drinking water for 18 weeks. Male Wistar rats were divided into five groups: control (CTRL), aluminum chloride (ALM, 34 mg/kg/day), fructose (FRCT), aluminum plus fructose (AL/FR), and GLYA (rats received AL/FR and treated with 40 mg/kg GLYA daily). AL/FR resulted in abnormal renal function tests and renal tissue injury. This was associated with increased oxidative stress and inflammation in the renal tissue. Moreover, the expressions of the toll-like receptor 4 (TLR4) and its adaptor proteins were increased in AL/FR group. The administration of GLYA mollified AL/FR-induced renal injury, oxidative stress, activation of the TLR4 signaling pathway, and inflammation. In conclusion, we provide evidence for the promising renoprotective effect of GLYA against AL/FR-induced kidney damage in rats. The renoprotection is attributed to the suppression of oxidative stress and inhibition of the TLR4/NF-κB signaling pathway in the kidneys.