Constitutive Androstane Receptor-Mediated Inhibition of Metformin on Phase II Metabolic Enzyme SULT2A1

Impact of metformin on gene expression in Burmese loach (Lepidocephalichthys berdmorei) from Manipur, India

Pharmaceutical contaminants like metformin, a widely used antidiabetic drug, pose emerging threats to aquatic ecosystems. This study investigates the endocrine-disrupting effects of metformin on Burmese loach (Lepidocephalichthys berdmorei), a bio-indicator species in Manipur's freshwater systems. Fish were exposed to 40 μg/L, 120 μg/L, and 360 μg/L of metformin for 28 days, and effects on gene expression, gonadal histology, and molecular interactions were assessed. Gene expression analysis revealed significant upregulation of AR, SULT2A1, CYP19A1, and 17β-HSD in metformin-treated males (p < 0.05). 3β-HSD was notably elevated at 360 μg/L. Despite these molecular changes, no histological differences were observed between treated and control groups. Molecular docking showed that SULT2A1 had the strongest interaction with metformin (-5.2 kcal/mol), followed by CYP19A1 (-5.0 kcal/mol) and AR (-4.9 kcal/mol). Molecular dynamics (MD) simulations confirmed the stability of the SULT2A1-metformin complex, with reduced RMSD, compactness, and residue fluctuations at the active site. The binding free energy (∆G) of -5.24 kcal/mol further supports this stable interaction. Additionally, structural deviations were observed in SULT2A1 upon metformin binding, suggesting potential functional alterations. These findings suggest that metformin alters endocrine function in L. berdmorei by modulating gene expression and interacting with key endocrine proteins, particularly SULT2A1. As L. berdmorei plays a crucial role in freshwater ecosystems, such disruptions may impact aquatic biodiversity. This study provides novel insights into metformin's molecular toxicity and highlights L. berdmorei as a potential model for xenoestrogen detection in freshwater environments.

Yinchenhao decoction alleviates obstructive jaundice liver injury by modulating epidermal growth factor receptor and constitutive androstane receptor signaling

BACKGROUND

Yinchenhao decoction (YCHD) is a traditional Chinese medicine widely used to treat liver damage caused by obstructive jaundice (OJ). Although YCHD has demonstrated protective effects against liver damage, reduced apoptosis, and mitigated oxidative stress in OJ, the precise molecular mechanisms involved remain poorly understood.

AIM

To investigate the beneficial effects of YCHD on OJ and elucidate the underlying mechanisms.

METHODS

The active constituents of YCHD were identified using liquid chromatography-tandem mass spectrometry, and their potential targets for OJ treatment were predicted through network pharmacology. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed. An OJ rat model was established by common bile duct ligation. Rats were divided into three groups: Sham surgery (S Group), model (O Group), and YCHD (Y Group). YCHD was administered to Group Y for one week. Bilirubin levels, liver function parameters, and bile acid concentrations in blood and urine were measured by enzyme-linked immunosorbent assay. The bile acid renal clearance rate (Clr) was calculated. Histopathological evaluation of liver and kidney tissues was performed using hematoxylin-eosin staining. Western blotting was utilized to assess the expression of key bile acid metabolism and transport proteins in both liver and kidney tissues. The expression of the constitutive androstane receptor (CAR) and its nuclear localization were evaluated by immunohistochemistry. Molecular docking studies identified the epidermal growth factor receptor (EGFR) as a potential target of YCHD's active components. An OJ cell model was created using human liver (L02) and renal tubular epithelial (HK-2) cells, which were treated with YCHD-containing serum. Western blotting and immunofluorescence assays were employed to evaluate CAR expression and its nuclear localization in relation to EGFR activation.

RESULTS

Network analysis identified the EGFR signaling pathway as a key mechanism through which YCHD exerts its effects on OJ. In vivo experiments showed that YCHD improved liver function, reduced OJ-induced pathology in liver and kidney tissues, and decreased serum bile acid content by enhancing bile acid Clr and urine output. YCHD also increased CAR expression and nuclear heterotopy, upregulating proteins involved in bile acid metabolism and transport, including CYP3A4, UGT1A1, MRP3, and MRP4 in the liver, and MRP2 and MRP4 in the kidneys. In vitro, YCHD increased CAR expression and nuclear heterotopy in L02 and HK-2 cells, an effect that was reversed by EGFR agonists.

CONCLUSION

YCHD enhances bile acid metabolism in the liver and promotes bile acid excretion in the kidneys, ameliorating liver damage caused by OJ. These effects are likely mediated by the upregulation of CAR and its nuclear translocation.

In Vitro and In Ovo Evaluation of the Potential Hepatoprotective Effect of Metformin

Background and Objectives: Metformin is currently the leading drug of choice for treating type 2 diabetes mellitus, being one of the most widely used drugs worldwide. The beneficial effects of Metformin, however, extend far beyond the reduction of blood glucose. Therefore, this study aimed to evaluate Metformin's effects both in vitro and in ovo. Materials and Methods: Metformin has been tested in five different concentrations in human hepatocytes -HepaRG, in terms of cell viability, morphology, structure and number of nuclei and mitochondria, as well as the effect on cell migration. Through the application of HET-CAM, the biocompatibility and potential anti-irritant, as well as protective effects on the vascular plexus were also assessed. Results: According to the results obtained, Metformin increases cell viability without causing morphological changes to cells, mitochondria, or nuclei. Metformin displayed an anti-irritant activity rather than causing irritation at the level of the vascular plexus. Conclusions: In conclusion, Metformin enhances cell viability and proliferation and, has a protective effect on the vascular plexus. Nonetheless, more studies are required to clarify the mechanism of hepatoprotective effect of metformin.

Metformin attenuates high glucose-induced injury in islet microvascular endothelial cells

As one of the most frequently prescribed antidiabetic drugs, metformin can lower glucose levels, improve insulin resistance manage body weight. However, the effect of metformin on islet microcirculation remains unclear. In the present study, to explore the effect of metformin on islet endothelial cells and investigated the underlying mechanism, we assessed the effects of metformin on islet endothelial cell survival, proliferation, oxidative stress and apoptosis. Our results suggest that metformin stimulates the proliferation of pancreatic islet endothelial cells and inhibits the apoptosis and oxidative stress caused by high glucose levels. By activating farnesoid X receptor (FXR), metformin increases the expression of vascular endothelial growth factor-A (VEGF-A) and endothelial nitric oxide synthase (eNOS), improves the production of nitric oxide (NO) and decreases the production of ROS. After the inhibition of FXR or VEGF-A, all of the effects disappeared. Thus, metformin appears to regulate islet microvascular endothelial cell (IMEC) proliferation, apoptosis and oxidative stress by activating the FXR/VEGF-A/eNOS pathway. These findings provide a new mechanism underlying the islet-protective effect of metformin.