Pyruvate dehydrogenase activation precedes the down-regulation of fatty acid oxidation in monocrotaline-induced myocardial toxicity in mice

Traditional uses, phytochemistry, pharmacology, toxicity and clinical application of traditional Chinese medicine Cynoglossum amabile: a review

Cynoglossum amabile, a member of the Boraginaceae family, is a well-known traditional Chinese medicine and ethnomedicine known as Daotihu. Despite several studies confirming the presence of bioactive pyrrolizidine alkaloids such as amabiline, ambelline, echinatine, europine, and others in C. amabile, there has been no comprehensive review of its traditional uses, phytochemistry, and pharmacology thus far. This review was conducted by thoroughly examining the literature and analyzing network databases. It covers various aspects of C. amabile, including botanical characteristics, geographical distribution, traditional applications, phytochemistry, pharmacological activities, toxicology, and clinical applications. The results have shown that C. amabile has been traditionally used for medicinal, edible, and ornamental purposes in China for many centuries. The whole plant, root, and leaf of C. amabile are used by different ethnic groups, such as Lisu, Bai, Naxi, Yi, Jinuo, and Han, to treat malaria, hepatitis, dysentery, leucorrhea, tuberculosis cough, fracture, joint dislocation, trauma bleeding, and skin carbuncle abscess. A total of 47 chemical components, including alkaloids (pyrrolizidine alkaloids, PAs), sterols, organic acids, and saccharides, were isolated from C. amabile. Pharmacological studies show that the chemical extracts of C. amabile possess various biological activities, such as anti-inflammatory, anti-tumor, anti-microbial, cardiovascular effects, ganglionic action, and acetylcholinesterase inhibition. However, it is important to note that C. amabile exhibits hepatotoxicity, with its toxicity being linked to its primary PAs components. Although preliminary studies suggest potential applications in the treatment of prostate diseases and alopecia, further research is needed to validate these clinical uses. Our review highlights the traditional uses, phytochemistry, biological activity, toxicity, and clinical applications of C. amabile. It emphasizes the essential guiding role of the indigenous medicinal knowledge system in developing new drugs. Previous studies have shown that the phytochemical and pharmacological characteristics of C. amabile are significantly related to its traditional medicinal practices. Cynoglossum amabile has excellent market potential and can be further analyzed in terms of phytochemistry, pharmacology, and toxicology, which are critical for its clinical drug safety, quality evaluation, and resource development.

Mitochondrial dysfunction in heart failure and its therapeutic implications

The ATP consumption in heart is very intensive to support muscle contraction and relaxation. Mitochondrion is the power plant of the cell. Mitochondrial dysfunction has long been believed as the primary mechanism responsible for the inability of energy generation and utilization in heart failure. In addition, emerging evidence has demonstrated that mitochondrial dysfunction also contributes to calcium dysregulation, oxidative stress, proteotoxic insults and cardiomyocyte death. These elements interact with each other to form a vicious circle in failing heart. The role of mitochondrial dysfunction in the pathogenesis of heart failure has attracted increasing attention. The complex signaling of mitochondrial quality control provides multiple targets for maintaining mitochondrial function. Design of therapeutic strategies targeting mitochondrial dysfunction holds promise for the prevention and treatment of heart failure.

Hepatotoxicity of Pyrrolizidine Alkaloid Compound Intermedine: Comparison with Other Pyrrolizidine Alkaloids and Its Toxicological Mechanism

Pyrrolizidine alkaloids (PAs) are common secondary plant compounds with hepatotoxicity. The consumption of herbal medicines and herbal teas containing PAs is one of the main causes of hepatic sinusoidal obstruction syndrome (HSOS), a potentially life-threatening condition. The present study aimed to reveal the mechanism underlying the cytotoxicity of intermedine (Im), the main PA in Comfrey. We evaluated the toxicity of the retronecine-type PAs with different structures to cell lines derived from mammalian tissues, including primary mouse hepatocytes, human hepatocytes (HepD), mouse hepatoma-22 (H₂₂) and human hepatocellular carcinoma (HepG2) cells. The cytotoxicity of Im to hepatocyte was evaluated by using cell counting kit-8 assay, colony formation experiment, wound healing assay and dead/live fluorescence imaging. In vitro characterization showed that these PAs were cytotoxic and induced cell apoptosis in a dose-dependent manner. We also demonstrated that Im induced cell apoptosis by generating excessive reactive oxygen species (ROS), changing the mitochondrial membrane potential and releasing cytochrome c (Cyt c) before activating the caspase-3 pathway. Importantly, we directly observed the destruction of the cell mitochondrial structure after Im treatment through transmission electron microscopy (TEM). This study provided the first direct evidence of Im inducing hepatotoxicity through mitochondria-mediated apoptosis. These results supplemented the basic toxicity data of PAs and facilitated the comprehensive and systematic evaluation of the toxicity caused by PA compounds.

Relationship between Invasive and Non-Invasive Hemodynamic Measures in Experimental Pulmonary Hypertension

Introduction:

Animal models have been used to understand the pathophysiology of pulmonary hypertension, to describe the mechanisms of action and to evaluate promising active ingredients. The monocrotaline-induced pulmonary hypertension model is the most used animal model. In this model, invasive and non-invasive hemodynamic variables that resemble human measurements have been used. Aim: To define if non-invasive variables can predict hemodynamic measures in the monocrotaline-induced pulmonary hypertension model.

Materials and Methods:

Twenty 6-week old male Wistar rats weighing between 250-300g from the bioterium of the Universidad del Valle (Cali - Colombia) were used in order to establish that the relationships between invasive and non-invasive variables are sustained in different conditions (healthy, hypertrophy and treated). The animals were organized into three groups, a control group who was given 0.9% saline solution subcutaneously (sc), a group with pulmonary hypertension induced with a single subcutaneous dose of Monocrotaline 30 mg/kg, and a group with pulmonary hypertension with 30 mg/kg of monocrotaline treated with Sildenafil. Right ventricle ejection fraction, heart rate, right ventricle systolic pressure and the extent of hypertrophy were measured. The functional relation between any two variables was evaluated by the Pearson correlation coefficient.

Results:

It was found that all correlations were statistically significant (p <0.01). The strongest correlation was the inverse one between the RVEF and the Fulton index (r = -0.82). The Fulton index also had a strong correlation with the RVSP (r = 0.79). The Pearson correlation coefficient between the RVEF and the RVSP was -0.81, meaning that the higher the systolic pressure in the right ventricle, the lower the ejection fraction value. Heart rate was significantly correlated to the other three variables studied, although with relatively low correlation.

Conclusion:

The correlations obtained in this study indicate that the parameters evaluated in the research related to experimental pulmonary hypertension correlate adequately and that the measurements that are currently made are adequate and consistent with each other, that is, they have good predictive capacity.

Ursolic Acid Improves Monocrotaline-Induced Right Ventricular Remodeling by Regulating Metabolism

Pulmonary arterial hypertension (PAH) is a progressive and malignant disease characterized by pulmonary small arteries and right ventricle (RV) remodeling that can lead to severe RV dysfunction and death. The current therapeutic targets for RV dysfunction, which is strongly linked to mortality, are far from adequate. Therefore, we investigated the effect of ursolic acid (UA), a pentacyclic triterpenoid carboxylic acid, on PAH-induced RV remodeling and its underlying mechanism. We established a PAH model by injecting Sprague Dawley rats with monocrotaline (MCT, 60 mg/kg, ip), as verified by echocardiography and hemodynamic examination. Proteomic analysis was performed on RV samples using a Q Exactive high-field mass spectrometer, followed by KEGG enrichment analysis. The effect of 4 weeks of UA (50 mg/kg) treatment on RV remodeling was explored based on ultrasound, hemodynamic parameters, and histological changes, with the mechanism verified in vivo and in vitro by qRT-PCR and western blotting. RV hypertrophy, fibrosis, increased apoptosis, and abnormal metabolism were induced by MCT and suppressed by UA via a mechanism that changed the expression of key markers. UA also attenuated the Phenylephrine-induced hypertrophy of neonatal rat ventricular myocytes and upregulated peroxisome proliferator-activated receptor-alpha (PPARα), a key fatty acid metabolism regulator, and its downstream factor carnitine palmitoyl transferase 1b. In conclusion, UA exerts beneficial effects on PAH-induced RV dysfunction and remodeling by regulating PPARα-dependent fatty acid metabolism.