Taraxasterol protects against acetaminophen-induced hepatotoxicity by reducing liver inflammatory response and ameliorating oxidative stress in mice

Taraxacum mongolicum total triterpenoids and taraxasterol ameliorate benign prostatic hyperplasia by inhibiting androgen levels, inflammatory responses, and epithelial-mesenchymal transition via the TGFβ1/Smad signalling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Taraxacum mongolicum Hand.-Mazz. is a well-known plant used both medicinally and as food, commonly used in traditional Chinese medicine prescriptions to alleviate benign prostatic hyperplasia (BPH). However, the material basis and molecular mechanisms of T. mongolicum alone in improving BPH remain unclear. In recent years, triterpenoids have been considered to be a key chemical constituents for T. mongolicum to exert its biological activity.

AIM OF THE STUDY

To explore the therapeutic efficacy and underlying mechanism of total triterpenoids from T. mongolicum (TTM) and its active constituents against BPH.

MATERIALS AND METHODS

The chemical components of TTM were determined using UPLC-QTOF-MS analysis. We established a testosterone propionate (TP)-induced rat model of BPH to assess the potential of TTM in vivo. Subsequently, network pharmacology was combined with experimental results from a TGFβ1-stimulated BPH-1 cell model to reveal the molecular mechanism of TTM. The main active ingredient (taraxasterol, TAR) of TTM was screened by evaluating its antiproliferative ability against BPH-1 and WPMY cells. Eventually, RNA-sequencing, RT-qPCR, immunofluorescence, and Western blotting were employed to elucidate the potential molecular targets and signalling pathways of TAR in BPH rats.

RESULTS

TTM was mainly composed of ten pentacyclic triterpenoids and one phytosterol, including TAR, lupeol, β-amyrin, taraxerol, and their acetates. TTM ameliorated TP-induced BPH by decreasing androgen levels and repressing inflammatory responses and oxidative stress. Furthermore, TTM inhibited epithelial-mesenchymal transition (EMT) and extracellular matrix (ECM) deposition via impeding the TGFβ1/Smad signalling pathway in BPH-1 cells based on the network pharmacology. Among the main chemical components of TTM, TAR exerted the strongest antiproliferative activity in vitro, and inhibited the growth of BPH-1 and WPMY-1 cells in a concentration dependent manner. Importantly, TAR also reduced androgen levels and inflammatory responses to balance proliferation and apoptosis in BPH rats. Transcriptomic analysis showed that TAR attenuated collagen deposition in BPH by inhibiting ECM-receptor interaction pathway. In addition, TAR notably suppressed EMT and the TGFβ1/Smad signalling in BPH rats, as evidenced by reduced the protein levels of collagen I, a-SMA, Snail, TGFβ1, p-Smad2/Smad2, and p-Smad3/Smad3, alongside an increase in E-cadherin expression.

CONCLUSIONS

TTM or TAR could effectively improve TP-induced BPH by suppressing androgen levels, inflammatory response, and EMT via the TGFβ1/Smad signalling pathway. These findings may present new therapeutic approachs for BPH in clinical settings. Notably, this study is the first to systematically elucidate the therapeutic mechanism of triterpenoids from T. mongolicum in treating BPH.

Glycyrrhiza uralensis Fisch. Attenuates Dioscorea bulbifera L.-induced liver injury by regulating the FXR/Nrf2-BAs-related proteins and intestinal microbiota

ETHNOPHARMACOLOGICAL RELEVANCE

Dioscorea bulbifera L. (DBL) was a traditional Chinese medicine commonly used to treat goitre and cancer. Nevertheless, its clinical application may lead to liver injury. Glycyrrhiza uralensis Fisch. (GRR) was primarily utilized in traditional Chinese medicine for its ability to harmonize various medicines and mitigate the toxic effects of poisonous herbs. However, the role of GRR in mitigating the liver toxicity of DBL has not been established after combination.

AIM OF THE STUDY

This study aimed to clarify the protective effect of GRR against DBL-induced liver injury in mice and investigate its mechanisms of action.

MATERIALS AND METHODS

75% ethanol was employed to extract DBL and GRR. The extracted components were characterized using LC-MS. Mice were orally gavaged with extracts from each group for 30 days. After the experiment, the pathological changes in the liver of mice were evaluated. Additionally, biochemical markers associated with liver injury were assessed. The primary mechanisms through which GRR mitigates DBL-induced liver injury and the modulation of the liver-intestinal axis by GRR were explored utilizing untargeted metabolomics, targeted BAs metabolomics and 16S rDNA analyses. Furthermore, Western blot and qPCR assessed the protein and mRNA transcription of the farnesoid X receptor (FXR) and nuclear factor-erythroid 2-related factor 2 (Nrf2) as well as BA-related transporters.

RESULTS

GRR dose-dependently attenuated DBL-induced liver injury in mice. It mitigated hepatic pathological changes and alleviated hepatic inflammation and oxidative stress. GRR improved metabolic disorders induced by DBL in mice at the metabolite level, focusing on the ABC transporter. Moreover, GRR may be attributed to its activation of FXR/Nrf2 expression, reduction of cholesterol 7-alpha hydroxylase (CYP7A1) expression, promotion of bile salt export pump (BSEP), multi-drug resistance protein 2 (MRP2), P-glycoprotein (P-gp) and sodium taurocholate cotransport polypeptide (NTCP) expression, reduction of bile acid (BA) synthesis, promotion of BA efflux and reabsorption, and improvement of BA metabolic disorders. In addition, GRR ameliorated DBL-induced intestinal barrier injury and improved the structural organization of the intestinal flora, restoring the overall composition of the intestinal microbiota.

CONCLUSION

GRR exhibited significant alleviation of DBL-induced liver injury, potentially by modulating FXR/Nrf2-BA-related proteins, reducing hepatic BA accumulation, mitigating liver inflammation and oxidative stress, and regulating intestinal flora.

Sakuranetin Prevents Acetaminophen-Induced Liver Injury via Nrf2-Induced Inhibition of Hepatocyte Ferroptosis

Introduction

Oxidative stress is an important cause of acetaminophen (APAP)-induced liver injury (AILI). Sakuranetin (Sak) is an antitoxin from the cherry flavonoid plant with good antioxidant effects. However, whether sakuranetine has a protective effect on APAP-induced liver injury is not clear.

Methods

Mouse and HepG2 cell models of APAP injury were used to investigate the effect of sakuranetin on AILI and its mechanism. Serum transaminase levels, histological changes, inflammatory mediators, oxidative stress, ferroptosis-related markers and Nrf2 signaling pathway proteins were analyzed.

Results

Sakuranetin significantly reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), as well as inflammatory factor; increased HepG2 activity and decreased cell death; inhibited ROS production, increased glutathione (GSH) content, expression of Glutathione Peroxidase 4 (GPX4) and Solute Carrier Family 7 Member 11 (SLC7A11), and decreased malondialdehyde and Acyl-CoA Synthetase Long Chain Family Member 4 (ACSL4) expression in mice and HepG2 cells after APAP treatment. Further analysis showed that sakuranetin induced the activation of the NFE2 Like BZIP Transcription Factor 2 (Nrf2) signaling pathway in liver tissue and HepG2 cells and promoted the nuclear translocation of Nrf2. Moreover, the hepatoprotective effect of sakuranetin and its inhibitory effect on ferroptosis were significantly attenuated by the Nrf2 inhibitor ML385.

Conclusion

Sakuranetin alleviates AILI by activating the Nrf2 signaling pathway and inhibiting ferroptosis, and sakuranetin may be a potential therapeutic agent for the treatment of AILI.

Bioactive Compounds from Vegetal Organs of Taraxacum Species (Dandelion) with Biomedical Applications: A Review

Taraxacum officinale (dandelion) is a perennial flowering plant of the Asteraceae family that has spread globally and is well-known for its traditional uses. The aim of this work is to provide a detailed review of scientific literature on the genus Taraxacum from the last two decades, with particular emphasis on the biological and pharmacological characteristics of dandelions. The traditional use of Taraxacum species and their potential use in medicine are assessed. In addition, individual papers describing principal pathways and molecules modulated by Taraxacum in antitumoral, anti-inflammatory, antidiabetic, hepatoprotective, immunomodulatory, antimicrobial, and antioxidant activities are presented. This review of phytochemical studies reveals that dandelions contain a wide range of bioactive compounds, such as polyphenols, phytosterols, flavonoids, carotenoids, terpene, and coumarins, whose biological activities are actively explored in various areas of human health, some constituents having synergistic activities, including antioxidant, antimicrobial, anti-inflammatory and anticancer activities. The study provides a screening of Taraxacum sp. chemical composition, an assessment of the main pharmacological properties, and a description of relevant studies supporting the use of dandelion for its particularly valuable and diversified therapeutic potential in different diseases.