Celecoxib attenuates hepatosteatosis by impairing de novo lipogenesis via Akt-dependent lipogenic pathway

Metabolic complications of psychotropic medications in psychiatric disorders: Emerging role of de novo lipogenesis and therapeutic consideration

Although significant advances have been made in understanding the patho-physiology of psychiatric disorders (PDs), therapeutic advances have not been very convincing. While psychotropic medications can reduce classical symptoms in patients with PDs, their long-term use has been reported to induce or exaggerate various pre-existing metabolic abnormalities including diabetes, obesity and non-alcoholic fatty liver disease (NAFLD). The mechanism(s) underlying these metabolic abnormalities is not clear; however, lipid/fatty acid accumulation due to enhanced de novo lipogenesis (DNL) has been shown to reduce membrane fluidity, increase oxidative stress and inflammation leading to the development of the aforementioned metabolic abnormalities. Intriguingly, emerging evidence suggest that DNL dysregulation and fatty acid accumulation could be the major mechanisms associated with the development of obesity, diabetes and NAFLD after long-term treatment with psychotropic medications in patients with PDs. In support of this, several adjunctive drugs comprising of anti-oxidants and anti-inflammatory agents, that are used in treating PDs in combination with psychotropic medications, have been shown to reduce insulin resistance and development of NAFLD. In conclusion, the above evidence suggests that DNL could be a potential pathological factor associated with various metabolic abnormalities, and a new avenue for translational research and therapeutic drug designing in PDs.

Discovery and validation of COX2 as a target of flavonoids in Apocyni Veneti Folium: Implications for the treatment of liver injury

ETHNOPHARMACOLOGICAL RELEVANCE

Apocyni Veneti Folium (AVF), a popular traditional Chinese medicine (TCM), is known for its effects in soothing the liver and nerves and eliminating heat and water. It is relevant from an ethnopharmacological perspective. Pharmacological research has confirmed its benefits on antihypertension, antihyperlipidemia, antidepression, liver protection, immune system boosting, antiaging, and diabetic vascular lesions. Previous studies have shown that flavonoids, the active ingredients, have a hepatoprotective effect. However, the exact mechanism has not been clarified.

AIM OF THE STUDY

This study aimed to identify the active flavonoids in AVF and their corresponding targets for liver injury. Multiple methods were introduced to confirm the targets.

MATERIAL AND METHODS

AVF compounds were analyzed using liquid chromatography-mass spectrometry (LC-MS). Then, network pharmacology was utilized to screen potential hepatoprotection targets of the compounds. An enzyme activity assay was performed to determine the effect of the compounds on the targets. Biolayer interferometry (BLI) was applied to confirm the direct interaction between the compounds and the targets.

RESULTS

A total of 71 compounds were identified by LC-MS and 19 compounds and 112 shared targets were screened using network pharmacology. These common targets were primarily involved in the TNF signaling pathway, cancer pathways, hepatitis B, drug responses, and negative regulation of the apoptotic process. Flavonoids were the primary pharmacological substance basis of AVF. The cyclooxygenase 2 (COX2) protein was one of the direct targets of flavonoids in AVF. The enzyme activity assay and BLI-based intermolecular interactions demonstrated that the compounds astragalin, isoquercitrin, and hyperoside exhibited stronger inhibition of enzyme activity and a higher affinity with COX2 compared to epigallocatechin, quercetin, and catechin.

CONCLUSIONS

COX2 was preliminarily identified as a target of flavonoids, and the mechanism of the hepatoprotective effect of AVF might be linked to flavonoids inhibiting the activity of COX2. The findings can establish the foundation for future research on the traditional hepatoprotective effect of AVF on the liver and for clinical studies on liver disorders.

Human skin stem cell-derived hepatic cells as in vitro drug discovery model for insulin-driven de novo lipogenesis

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), is characterized by intrahepatic triglyceride accumulation and can progress to metabolic dysfunction-associated steatohepatitis (MASH) and liver fibrosis. Hepatic de novo lipogenesis (DNL), activated by glucose and insulin, is a central pathway contributing to early-stage development of MASLD. The emerging global prevalence of MASLD highlights the urgent need for pharmaceutical intervention to combat this health threat. However, the identification of novel drugs that could inhibit hepatic DNL is hampered by a lack of reliable, insulin-sensitive, human, in vitro, hepatic models. Here, we report human skin stem cell-derived hepatic cells (hSKP-HPC) as a unique in vitro model to study insulin-driven DNL (iDNL), evidenced by both gene expression and lipid accumulation readouts. Insulin-sensitive hSKP-HPC showed increased sterol regulatory element-binding protein 1c (SREBP-1c) expression, a key transcription factor for DNL. Furthermore, this physiologically relevant in vitro human steatosis model allowed both inhibition and activation of the iDNL pathway using reference inhibitors and activators, respectively. Optimisation of the lipid accumulation assay to a high-throughput, 384-well format enabled the screening of a library of annotated compounds, delivering new insights on key players in the iDNL pathway and MASLD pathophysiology. Together, these results establish the value of the hSKP-HPC model in preclinical development of antisteatotic drugs to combat MASLD.

Interdisciplinary advances reshape the delivery tools for effective NASH treatment

BACKGROUND

Nonalcoholic steatohepatitis (NASH), a severe systemic and inflammatory subtype of nonalcoholic fatty liver disease, eventually develops into cirrhosis and hepatocellular carcinoma with few options for effective treatment. Currently potent small molecules identified in preclinical studies are confronted with adverse effects and long-term ineffectiveness in clinical trials. Nevertheless, highly specific delivery tools designed from interdisciplinary concepts may address the significant challenges by either effectively increasing the concentrations of drugs in target cell types, or selectively manipulating the gene expression in liver to resolve NASH.

SCOPE OF REVIEW

We focus on dissecting the detailed principles of the latest interdisciplinary advances and concepts that direct the design of future delivery tools to enhance the efficacy. Recent advances have indicated that cell and organelle-specific vehicles, non-coding RNA research (e.g. saRNA, hybrid miRNA) improve the specificity, while small extracellular vesicles and coacervates increase the cellular uptake of therapeutics. Moreover, strategies based on interdisciplinary advances drastically elevate drug loading capacity and delivery efficiency and ameliorate NASH and other liver diseases.

MAJOR CONCLUSIONS

The latest concepts and advances in chemistry, biochemistry and machine learning technology provide the framework and strategies for the design of more effective tools to treat NASH, other pivotal liver diseases and metabolic disorders.

Eicosanoids and other oxylipins in liver injury, inflammation and liver cancer development

Liver cancer is a malignancy developed from underlying liver disease that encompasses liver injury and metabolic disorders. The progression from these underlying liver disease to cancer is accompanied by chronic inflammatory conditions in which liver macrophages play important roles in orchestrating the inflammatory response. During this process, bioactive lipids produced by hepatocytes and macrophages mediate the inflammatory responses by acting as pro-inflammatory factors, as well as, playing roles in the resolution of inflammation conditions. Here, we review the literature discussing the roles of bioactive lipids in acute and chronic hepatic inflammation and progression to cancer.