Activation of CREB Protein With Tabersonine Attenuates STAT3 During Atherosclerosis in Apolipoprotein E-Deficient Mice

Tabersonine enhances cisplatin sensitivity by modulating Aurora kinase A and suppressing epithelial-mesenchymal transition in triple-negative breast cancer

CONTEXT

Tabersonine has been investigated for its role in modulating inflammation-associated pathways in various diseases. However, its regulatory effects on triple-negative breast cancer (TNBC) have not yet been fully elucidated.

OBJECTIVE

This study uncovers the anticancer properties of tabersonine in TNBC cells, elucidating its role in enhancing chemosensitivity to cisplatin (CDDP).

MATERIALS AND METHODS

After tabersonine (10 μM) and/or CDDP (10 μM) treatment for 48 h in BT549 and MDA-MB-231 cells, cell proliferation was evaluated using the cell counting kit-8 and colony formation assays. Quantitative proteomics, online prediction tools and molecular docking analyses were used to identify potential downstream targets of tabersonine. Transwell and wound-healing assays and Western blot analysis were used to assess epithelial-mesenchymal transition (EMT) phenotypes.

RESULTS

Tabersonine demonstrated inhibitory effects on TNBC cells, with IC50 values at 48 h being 18.1 μM for BT549 and 27.0 μM for MDA-MB-231. The combined treatment of CDDP and tabersonine synergistically suppressed cell proliferation in BT549 and MDA-MB-231 cells. Enrichment analysis revealed that the proteins differentially regulated by tabersonine were involved in EMT-related signalling pathways. This combination treatment also effectively restricted EMT-related phenotypes. Through the integration of online target prediction and proteomic analysis, Aurora kinase A (AURKA) was identified as a potential downstream target of tabersonine. AURKA expression was reduced in TNBC cells post-treatment with tabersonine.

DISCUSSION AND CONCLUSIONS

Tabersonine significantly enhances the chemosensitivity of CDDP in TNBC cells, underscoring its potential as a promising therapeutic agent for TNBC treatment.

Tabersonine Induces the Apoptosis of Human Hepatocellular Carcinoma In vitro and In vivo

BACKGROUND

Tabersonine, a natural indole alkaloid derived from Apocynaceae plants, exhibits antiinflammatory and acetylcholinesterase inhibitory activities, among other pharmacological effects. However, its anti-tumor properties and the underlying molecular mechanisms remain underexplored.

OBJECTIVE

The present study aims to investigate the anti-tumor effects of tabersonine and its mechanisms in inducing apoptosis in hepatocellular carcinoma.

METHODS

The inhibitory effects of tabersonine on the viability and proliferation of liver cancer cells were evaluated using MTT assay and colony formation assay. AO/EB, Hoechst, and Annexin V-FITC/ PI staining techniques were employed to observe cell damage and apoptosis. JC-1 staining was used to detect changes in mitochondrial membrane potential. Western blot analysis was conducted to study the anti-tumor mechanism of tabersonine on liver cancer cells. Additionally, a xenograft model using mice hepatoma HepG2 cells was established to assess the anti-tumor potency of tabersonine in vivo.

RESULTS AND DISCUSSION

Our findings revealed that tabersonine significantly inhibited cell viability and proliferation, inducing apoptosis in liver cancer cells. Treatment with tabersonine inhibited Akt phosphorylation, reduced mitochondrial membrane potential, promoted cytochrome c release from mitochondria to the cytoplasm, and increased the ratio of Bax to Bcl-2. These findings suggested that tabersonine induces apoptosis in liver cancer cells through the mitochondrial pathway. Furthermore, tabersonine treatment activated the death receptor pathway of apoptosis. In vivo studies demonstrated that tabersonine significantly inhibited xenograft tumor growth.

CONCLUSION

Our study is the first to demonstrate that tabersonine induces apoptosis in HepG2 cells through both mitochondrial and death receptor apoptotic pathways, suggesting its potential as a therapeutic agent candidate for hepatic cancer.

Tabersonine alleviates obesity-induced cardiomyopathy by binding to Transforming growth factor activated kinase 1 (TAK1) and inhibiting TAK1-mediated inflammation

Obesity-induced cardiomyopathy (OIC) is an increasingly serious global disease caused by obesity. Chronic inflammation greatly contributes to the pathogenesis of OIC. This study aimed to explore the role and mechanism of tabersonine (Tab), a natural alkaloid with antiinflammatory activity, in the treatment of OIC. High fat diet (HFD)-induced obese mice were administered with Tab. The results showed that Tab significantly inhibit inflammation, myocardial fibrosis, and hypertrophy to prevent heart dysfunction, without the alteration of body weight and hyperlipidemia, in HFD-induced obese mice. H9c2 cells and primary cardiomyocytes stimulated by palmitic acid (PA) were used to explore the molecular mechanism and target of Tab. We examined the effect of Tab on key proteins involved in HFD/PA-induced inflammatory signaling pathway and found that Tab significantly inhibits TAK1 phosphorylation in cardiomyocytes. We further detected the direct interaction between Tab and TAK1 at the cellular, animal, and molecular levels. We found that Tab directly binds to TAK1 to inhibit TAK1 phosphorylation, which then blocks TAK1-TAB2 interaction and then NF-κB pro-inflammatory pathway in cultured cardiomyocytes. Our results indicate that Tab is a potential agent for the treatment of OIC, and TAK1 is an effective therapeutic target for this disease.

Tabersonine attenuates Angiotensin II-induced cardiac remodeling and dysfunction through targeting TAK1 and inhibiting TAK1-mediated cardiac inflammation

BACKGROUND

Angiotensin II (Ang II)-induced cardiac inflammation contribute to pathological cardiac remodeling and hypertensive heart failure (HF). Tabersonine (Tab) is an indole alkaloid mainly isolated from Catharanthus roseus and exhibits anti-inflammatory activity in various systems. However, the role of Tab in hypertensive HF and its molecular targets remains unknown.

HYPOTHESIS/PURPOSE

We aimed to investigate potential cardioprotective effects and mechanism of Tab against Ang II-induced cardiac injuries.

METHODS

C57BL/6 mice were administered Ang II (at 1000 ng/kg/min) by micro-osmotic pump infusion for 30 days to develop hypertensive HF. Tab at 20 and 40 mg/kg/day was administered during the last 2 weeks to elucidate the cardioprotective properties. Cultured cardiomyocyte-like H9c2 cells and rat primary cardiomyocytes were used for mechanistic studies of Tab.

RESULTS

We demonstrate for the first time that Tab provides protection against Ang II-induced cardiac dysfunction in mice, associated with reduced cardiac inflammation and fibrosis. Mechanistically, we show that Tab may interacts with TAK1 to inhibit Ang II-induced TAK1 ubiquitination and phosphorylation. Disruption of TAK1 activation by Tab blocked downstream NF-κB and JNK/P38 MAPK signaling activation and decreased cardiac inflammation and fibrosis both in vitro and in vivo. TAK1 knockdown also blocked Ang II-induced cardiomyocytes injuries and prevented the innately pharmacological effects of Tab.

CONCLUSION

Our results indicate that Tab protects hearts against Ang II-mediated injuries through targeting TAK1 and inhibiting TAK1-mediated inflammatory cascade and response. Thus, Tab may be a potential therapeutic candidate for hypertensive HF.

Aspidosperma and Strychnos alkaloids: Chemistry and biology

Of Nature's nearly 3000 unique monoterpene indole alkaloids derived from tryptophan, those members belonging to the Aspidosperma and Strychnos families continue to impact the fields of natural products (i.e., isolation, structure determination, biosynthesis) and organic chemistry (i.e., chemical synthesis, methodology development) among others. This review covers the biological activity (Section 2), biosynthesis (Section 3), and synthesis of both classical and novel Aspidosperma (Section 4), Strychnos (Section 5), and selected bis-indole (Section 6) alkaloids. Technological advancements in genetic sequencing and bioinformatics have deepened our understanding of how Nature assembles these intriguing molecules. The proliferation of innovative synthetic strategies and tactics for the synthesis of the alkaloids covered in this review, which include contributions from over fifty research groups from around the world, are a testament to the creative power and technical skills of synthetic organic chemists. To be sure, Nature-the Supreme molecular architect and source of a dazzling array of irresistible chemical logic puzzles-continues to inspire scientists across multiple disciplines and will certainly continue to do so for the foreseeable future.

IL-6/STAT3 signaling pathway regulates the proliferation and damage of intestinal epithelial cells in patients with ulcerative colitis via H3K27ac

The aim of the present study was to investigate the effect of the IL-6/STAT3 signaling pathway on intestinal epithelial barrier injury in patients with ulcerative colitis (UC). Fifty-two patients with UC and 21 healthy subjects were recruited. The expression level of IL-6 in plasma was determined by ELISA. Normal human colon mucosal epithelial NCM460 cells were treated with IL-6 or plasma from the patients with UC. Then, the transepithelial electrical resistance value, fluorescein yellow permeability and zonulin release were evaluated. Using reverse transcription-quantitative (q)PCR and western blotting, claudin (CLDN) 1 and CLDN2 expression levels were analyzed. Furthermore, western blotting was used to detect phosphorylation of STAT3. Chromatin immunoprecipitation-qPCR was performed to investigate the enrichment of H3K27ac in the promoter regions of CLDN1 and CLDN2. The present study revealed that IL-6 content was elevated in the plasma from patients with UC and increased with the progression of the disease. IL-6 was also observed to induce intestinal epithelial cell barrier injury and regulate barrier function by influencing the expression of tight junction-related proteins, as well as STAT3. The IL-6/STAT3 signaling pathway regulated transcription of CLDN1 and CLDN2 by affecting the enrichment of histone H3K27ac in their promoter regions. Thus, the significantly increased expression level of IL-6 in the peripheral blood of patients with UC indicates a positive association with the development of UC. Furthermore, the IL-6/STAT3 signaling pathway influences the function of the intestinal barrier by affecting the H3K27ac level in intestinal epithelial cells.

Current state and future perspective of cardiovascular medicines derived from natural products

The contribution of natural products (NPs) to cardiovascular medicine has been extensively documented, and many have been used for centuries. Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide. Over the past 40 years, approximately 50% of newly developed cardiovascular drugs were based on NPs, suggesting that NPs provide essential skeletal structures for the discovery of novel medicines. After a period of lower productivity since the 1990s, NPs have recently regained scientific and commercial attention, leveraging the wealth of knowledge provided by multi-omics, combinatorial biosynthesis, synthetic biology, integrative pharmacology, analytical and computational technologies. In addition, as a crucial part of complementary and alternative medicine, Traditional Chinese Medicine has increasingly drawn attention as an important source of NPs for cardiovascular drug discovery. Given their structural diversity and biological activity NPs are one of the most valuable sources of drugs and drug leads. In this review, we briefly described the characteristics and classification of NPs in CVDs. Then, we provide an up to date summary on the therapeutic potential and the underlying mechanisms of action of NPs in CVDs, and the current view and future prospect of developing safer and more effective cardiovascular drugs based on NPs.