The cyclin-dependent kinase inhibitor abemaciclib-induced hepatotoxicity: Insight on the molecular mechanisms in HepG2/THP-1 co-culture model.

Drug-induced liver injury (DILI) is one of the widespread causes of liver injury and immune system plays important role. Abemaciclib (ABE) is a cyclin-dependent kinase inhibitor used as monotherapy or combination therapy in the treatment of breast cancer. Like other kinase inhibitors, the underlying mechanisms of ABE-induced hepatotoxicity are not completely known yet. In the current study, hepatotoxicity of ABE was evaluated with HepG2/THP-1 co-culture model which has been developed in recent years for the evaluation of DILI potential. Following ABE treatment, oxidative stress, mitochondrial damage, cytokine secretion levels, apoptotic/necrotic cell death were determined. According to our results, ROS production along with GSH depletion was observed in HepG2 cells after ABE treatment. ABE promoted secretion of pro-inflammatory mediators (TNF-α and MCP-1) and declined anti-inflammatory cytokine IL-10 release. Besides, NFKß and JNK1 protein expression levels increased following ABE treatment. ABE enhanced intracellular calcium levels, induced early apoptotic and necrotic cell deaths in HepG2 cells. Furthermore, the changes in some mitochondrial parameters including a reducement in intracellular ATP levels and complex V activity; hyperpolarized mitochondrial membrane potential and enhanced mitochondrial ROS levels were observed, whereas mitochondrial mass did not show any differences after ABE treatments. Therefore, ABE-induced hepatotoxic effects is probably via oxidative stress, inflammatory response and necrotic cell death rather than direct mitochondrial toxicity. In conclusion; the study makes a significant contribution to strengthening the infrastructure we have on in vitro toxicity mechanism evaluations, which are the basis of preclinical toxicity studies.

Phytochemical profiling of Salsola tetragona Delile by LC-HR/MS and investigation of the antioxidant, anti-inflammatory, cytotoxic, antibacterial and anti-SARS-CoV-2 activities.

This study aimed to investigate the phytochemical composition and biological activity of Salsola tetragona Delile. (Amaranthaceae), a medicinal plant. The study evaluated the antioxidant potential of the crude extract and five fractions of S. tetragona using DPPH•, ABTS•+, CUPRAC, and metal chelating assays. The anti-inflammatory activity was determined using a protein denaturation assay, and the antibacterial activity was determined by the Minimum inhibitory concentrations (MICs) for the growth of Escherichia coli and Staphylococcus aureus strains. The MTT test and an in vitro scratch assay evaluated the effects on cell viability and cell migration. The potential anti-SARS-CoV-2 activity was assessed by analyzing the effects on the interaction between ACE2 and Spike protein. The bioactive compounds present in the plant were identified using LC-HR/MS analysis. The crude hydromethanolic extract (STM) and five fractions of S. tetragona, n-hexane (STH), dichloromethane (STD), ethyl acetate (STE), n-butanol (STB), and aqueous (STW) showed significant antioxidant activity in four different tests. In the anti-inflammatory assay, the ethyl acetate fraction exhibited significantly higher activity than Aspirin® (IC50 = 13 ± 5 µg/mL). The crude extract and its fractions showed positive antibacterial activity with similar MICs. In the cytotoxicity assay against the breast cancer cell line MCF7, the dichloromethane fractions (STD) were very effective and demonstrated superiority over the other fractions (IC50 = 98 µg/mL). Moreover, the potential of the extract and fractions as anti-SARS-CoV-2, the ethyl acetate, and dichloromethane fractions demonstrated important activity in this test. LC-HR/MS analysis identified 16 different phenolic compounds, Eleven of which had not been previously reported in the genus Salsola. The results suggest that the extracts of S. tetragona have the potential to become new sources for developing plant-based therapies for managing a range of diseases.

Emodin and aloe-emodin, two potential molecules in regulating cell migration of skin cells through the MAP kinase pathway and affecting Caenorhabditis elegans thermotolerance.

BACKGROUND: Emodin and aloe-emodin are two anthraquinones having positive effects in wound healing. However, their mechanism of action of wound healing is not fully understood. The MAP kinase family, which plays an active role in wound healing, is a well-characterized large family of serine/threonine kinases and regulates processes such as proliferation, oncogenesis, differentiation, and inflammation in the cell. The aim of this study is to comparatively elucidate the mechanisms of action of emodin and aloe-emodin, which are potential agents in wound healing. METHODS: The mechanism of the effects of emodin and aloe-emodin on cell viability and cell migration was examined using the human skin fibroblast (CCD-1079Sk) cell line. The gene expression levels of the MAP kinases (JNK, P38, ERK) in the skin fibroblast cells along with a molecular docking study analyzing their interaction potential were evaluated. Furthermore, the molecules' effects on the lifespan of Caenorhabditis elegans were studied. RESULTS: Emodin and aloe-emodin inhibited the ATP content of the cells in a concentration dependent manner and accelerated cell migration at the lower concentrations while inhibiting cell migration in the higher concentration treatment groups. The expressions of JNK and P38 were upregulated at the low concentrations and downregulated at the higher concentrations. The molecular docking studies of the molecules gave high docking scores indicating their interaction potential with JNK and P38. C. elegans lifespan under heat stress was observed longer after 75 µM emodin and was significantly reduced after 150 µM aloe-emodin treatment. CONCLUSION: Aloe-emodin was found to be more potent on cell viability, cell migration, gene expression levels of the MAP kinases in healthy fibroblastic skin cells, and on the lifespan of C. elegans. This study reveals the functional effects and the biological factors that interact in the wound healing process of emodin and aloe-emodin, and give a possible treatment alternative to shorten the duration of wound care.

Molecular Cardiotoxic Effects of Proteasome Inhibitors Carfilzomib and Ixazomib and Their Combination with Dexamethasone Involve Mitochondrial Dysregulation.

With the development and approval of new proteasome inhibitors, proteasome inhibition is increasingly recognized in cancer therapy. Besides successful anti-cancer effects in hematological cancers, side effects such as cardiotoxicity are limiting effective treatment. In this study, we used a cardiomyocyte model to investigate the molecular cardiotoxic mechanisms of carfilzomib (CFZ) and ixazomib (IXZ) alone or in combination with the immunomodulatory drug dexamethasone (DEX) which is frequently used in combination therapies in the clinic. According to our findings, CFZ showed a higher cytotoxic effect at lower concentrations than IXZ. DEX combination attenuated the cytotoxicity for both proteasome inhibitors. All drug treatments caused a marked increase in K48 ubiquitination. Both CFZ and IXZ caused an upregulation in cellular and endoplasmic reticulum stress protein (HSP90, HSP70, GRP94, and GRP78) levels and DEX combination attenuated the increased stress protein levels. Importantly, IXZ and IXZ-DEX treatments caused upregulation of mitochondria fission and fusion gene expression levels higher than caused by CFZ and CFZ-DEX combination. The IXZ-DEX combination reduced the levels of OXPHOS proteins (Complex II-V) more than the CFZ-DEX combination. Reduced mitochondrial membrane potential and ATP production were detected with all drug treatments in cardiomyocytes. Our findings suggest that the cardiotoxic effect of proteasome inhibitors may be due to their class effect and stress response and mitochondrial dysfunction may be involved in the cardiotoxicity process.

Fungal biotransformation of carvone and camphor by Aspergillus flavus and investigation of cytotoxic activities of naturally obtained essential oils.

In this study, the biotransformation of carvone and camphor by Aspergillus flavus and the products were investigated. The biotransformation reaction of carvone by A. flavus resulted in the production of neodihydrocarveol, dihydrocarvone, 2-cyclohexene-1-one,2-methyl-5-(1-methylethenyl), limonene-1,2-diol, trans-p-mentha-1(7),8-dien-2-ol, p-menth-8(10)-ene-2,9-diol, and the biotransformation reaction of camphor resulted in the production of 2 -campholenic acid, 2-cyclohexene-1-one,2-hydroxy-4,4,6,6-tetramethyl, α-campholene aldehyde. The naturally produced essential oils by biotransformation of carvone and camphor were observed to be cytotoxic to breast cancer cells while no significant inhibition was seen in the healthy cell line. Additionally, biotransformation products had the highest inhibition (74%) against aflatoxin B1. The bioactivities of biotransformation products are promising, and they can be further investigated for their therapeutic potential as active agents.

Favipiravir induces oxidative stress and genotoxicity in cardiac and skin cells.

Favipiravir (T-705), used against influenza viruses, is approved for emergency use in many countries for the treatment of COVID-19. The frequent adverse effects of favipiravir are related with the gastrointestinal system, however, studies suggest a positive association of favipiravir on QTc prolongation, which can cause cardiotoxicity. Also, there are reports of skin reactions such as angioedema due to favipiravir. Despite the several adverse effects, studies examining the drug's effects at the molecular level are insufficient, e.g., the genotoxic and oxidative stress-inducing effects of favipiravir, which are among the primary mechanisms of drug-induced toxicity. The cytotoxicity of favipiravir was analyzed with the measurement of the ATP content in H9c2 cardiomyoblasts and CCD-1079Sk skin fibroblasts. The ATP level decreased starting from 200 µM. The inhibitory effect on the mitochondrial electron transport chain enzymes complex I and complex V was also evaluated where favipiravir showed significant enzyme inhibitory effects in the highest concentration studied. A molecular docking study evaluating the interaction between favipiravir-RTP and mitochondrial DNA polymerase (POLG1) was done. The relationship of favipiravir with oxidative stress was examined by measuring glutathione (GSH) and protein carbonyl levels which were observed higher after drug treatment compared to the control group. The genotoxicity study was done using the Comet assay and increase in DNA tail has been detected. Furthermore, 8-OHdG levels were measured higher in favipiravir treated cells indicating oxidative DNA damage. Favipiravir induced oxidative stress leading to DNA damage in cardiomyoblast cells and fibroblastic skin cells. Oxidative stress and DNA damage might eventually lead to organ-specific damage such as cardiotoxicity and dermal toxicity. Considering the increased use of favipiravir in recent years, and that oxidative stress and genotoxicity are two important indicators of drug-induced toxicity, the obtained results are worth attention.

Impact of the Gastrointestinal Tract Microbiota on Cardiovascular Health and Pathophysiology.

ABSTRACT: The microbiota of the gastrointestinal tract (GIT) is an extremely diverse community of microorganisms, and their collective genomes (microbiome) provide a vast arsenal of biological activities, particularly enzymatic ones, which are far from being fully elucidated. The study of the microbiota (and the microbiome) is receiving great interest from the biomedical community because it carries the potential to improve risk prediction models, refine primary and secondary prevention efforts, and also design more appropriate and personalized therapies, including pharmacological ones. A growing body of evidence, although sometimes impaired by the limited number of subjects involved in the studies, suggests that GIT dysbiosis, that is, the altered microbial composition, has an important role in causing and/or worsening cardiovascular disease (CVD). Bacterial translocation and the alteration of levels of microbe-derived metabolites can thus be important to monitor and modulate because they may lead to initiation and progression of CVD and to its establishment as chronic state. We hereby aim to provide readers with details on available resources and experimental approaches that are used in this fascinating field of biomedical research and on some novelties on the impact of GIT microbiota on CVD.

Synthesis, anti-TB activities, and molecular docking studies of 4-(1,2,3-triazoyl)arylmethanone derivatives.

Infectious diseases such as tuberculosis (TB) are leading causes of human death. Antibiotics are effective molecules to combat bacterial infections by affecting the processes required for bacterial cell growth and proliferation. The development of new antibiotics has become an important issue as overdosed or incorrect use of antibiotic lead to the development of antibiotic resistance. In this study, a new series of 4-(1,2,3-triazoyl)arylmethanone derivatives has been synthesized using the one-pot Copper-​Catalyzed Oxidative Cross-​Dehydrogenative Coupling​/Oxidative Cycloaddition strategy to overcome the aforementioned problems. New compounds were characterized by using spectroscopic techniques (1 H, 13 C-APT-NMR, FT-IR, and HRMS-TOF). In vitro antimycobacterial activities of the arylmethanone derivatives against the Mycobacterium tuberculosis H37 Rv standard strain were examined using the resazurin microplate method in the presence of streptomycin and rifampycin as standard medicines. Bioactive assays demonstrated promising results that some of the synthesized 4-(1,2,3-triazoyl)arylmethanone derivatives exhibited good anti-TB activities. Notably, compounds 6b, 6f, and 6g gave the most potent efficiency with minimum inhibitory concentration values of 4 µg/ml (12.8, 11.7, and 12.8 µΜ, respectively). Among the synthesized compounds, the cytotoxicity measurements of the 6b, 6f, 6g, 6d, and 6v derivatives were screened and it was found that the 6f derivative did not show any cytotoxicity. Molecular docking analyses are utilized to identify the binding mode and the key interactions between target compounds and the ligand-binding site of M. tuberculosis enoyl-acyl carrier protein reductase enzyme (MtInhA, EC 1.3.1.9). The docking results were in agreement with the in vitro results, which confirm the synthesized ligands bind to MtInha with moderate to low affinity.

Mitochondrial dynamics imbalance and mitochondrial dysfunction contribute to the molecular cardiotoxic effects of lenvatinib.

Lenvatinib is a tyrosine kinase inhibitor (TKI) approved for the treatment of resistant differentiated thyroid cancer, advanced renal cell carcinoma, unresectable hepatocellular carcinoma, and endometrial carcinoma. Although it is successful in cancer treatment, it can cause life-threatening side effects such as cardiotoxicity. The molecular mechanism of cardiotoxicity caused by lenvatinib is not fully known. In this study, the molecular mechanism of lenvatinib's cardiotoxicity was investigated focusing on mitochondrial toxicity in the H9c2 cardiomyoblastic cell line. Lenvatinib inhibited cell viability at 48 and 72 h exposure with three selected concentrations (1.25 µM, 5 µM and 10 µM); and inhibited intracellular ATP after 72 h exposure compared to the control group. Mitochondrial membrane potential was decreased after 48 h and did not show significant changes after 72 h exposure. Evaluated with real-time PCR, mitochondrial dynamics (Mfn1, Mfn2, OPA1, DRP1, Fis1) expression levels after lenvatinib treatment significantly changed. Lenvatinib triggered the tendency from fusion to fission in mitochondria after 48 h exposure, and increased both fusion and fission after 72 h. The mtDNA ratio increased after 48 h and decreased after 72 h. ASK1, JNK and AMPKα2 increased. UCP2 showed downregulation, SOD2 level showed upregulation and Cat levels decreased after drug treatment. Nrf1 and Nrf2 also changed concentration-dependently. Protein carbonyl levels increased significantly after lenvatinib treatments indicating oxidative stress. The protein levels of the electron transport chain complexes, LONP1, UCP2, and P21 showed significant differences after lenvatinib treatment. The outcome of our study is expected to be a contribution to the understanding of the molecular mechanisms of TKI-induced cardiotoxicity.