Synthesis and In Vivo Antiarrhythmic Activity Evaluation of Novel Scutellarein Analogues as Voltage-Gated Nav1.5 and Cav1.2 Channels Blockers

Nuciferine analogs block voltage-gated sodium, calcium and potassium channels to regulate the action potential and treat arrhythmia

Dysfunction of the Nav1.5, Cav1.2, and Kv channels could interfere with the AP and result in arrhythmias and even heart failure. We herein present a novel library of nuciferine analogs that target ion channels for the treatment of arrhythmias. Patch clamp measurements of ventricular myocytes revealed that 6a dramatically blocked both the INa and ICa without altering the currentvoltage relationship (including the activation potential and peak potential), accelerated the inactivation of Nav and Cav channels and delayed the resurrection of these channels after inactivation. Additionally, 6a significantly decreased the APA and RMP without affecting the APD30 or APD50. The IC50 values of 6a against Nav1.5 and Cav1.2 were 4.98 μM and 4.62 μM, respectively. Furthermore, 6a (10 μM) blocked IKs, IK1, and Ito with values of 17.01 %±2.54 %, 9.09 %±2.78 %, and 11.15 %±3.52 %, respectively. Surprisingly, 6a weakly inhibited hERG channels, suggesting a low risk of proarrhythmia. The cytotoxicity evaluation of 6a with the H9c2 cell line indicated that this compound was noncytotoxic. In vivo studies suggested that these novel nuciferine analogs could shorten the time of arrhythmia continuum induced by BaCl2 and normalize the HR, QRS, QT and QTc interval and the R wave amplitude. Moreover, 6a dose-dependently affected aconitine-induced arrhythmias and notably improved the cumulative dosage of aconitine required to evoke VP, VT, VF and CA in rats with aconitine-induced arrhythmia. In conclusion, nuciferine analogs could be promising ion channel blockers that could be further developed into antiarrhythmic agents.

Review on the pharmacological effects and pharmacokinetics of scutellarein

Scutellarein is a flavonoid from Scutellaria baicalensis Georgi that has been shown to have a variety of pharmacological activities. This review aims to summarize the pharmacological and pharmacokinetic studies on scutellarein and provide useful information for relevant scholars. Pharmacological studies indicate that scutellarein possesses a diverse range of pharmacological properties, including but not limited to anti-inflammatory, antioxidant, antiviral, neuroprotective, hypoglycemic, hypolipidemic, anticancer, and cardiovascular protective effects. Further investigation reveals that the pharmacological effects of scutellarein are driven by multiple mechanisms. These mechanisms encompass the scavenging of free radicals, inhibition of the activation of inflammatory signaling pathways and expression of inflammatory mediators, inhibition of the activity of crucial viral proteins, suppression of gluconeogenesis, amelioration of insulin resistance, improvement of cerebral ischemia-reperfusion injury, induction of apoptosis in cancer cells, and prevention of myocardial hypertrophy, among others. In summary, these pharmacological studies suggest that scutellarein holds promise for the treatment of various diseases. It is imperative to conduct clinical studies to further elucidate the therapeutic effects of scutellarein. However, it is worth noting that studies on the pharmacokinetics reveal an inhibitory effect of scutellarein on uridine 5'-diphosphate glucuronide transferases and cytochrome P450 enzymes, potentially posing safety risks.

Barium Chloride-Induced Cardiac Arrhythmia Mouse Model Exerts an Experimental Arrhythmia for Pharmacological Investigations

AIM

Cardiac arrhythmias are among the most important pathologies that cause sudden death. The exploration of new therapeutic options against arrhythmias with low undesirable effects is of paramount importance.

METHODS

However, the convenient and typical animal model for screening the potential lead compound becomes a very critical modality, particularly in anti-arrhythmia. In this study, mice were intraperitoneally (i.p.) injected with BaCl2, CaCl2, and adrenaline to induce arrhythmia, and simultaneously compared with BaCl2-induced rats.

RESULTS

Electrocardiogram (ECG) showed that the majority of mice repeatedly developed ventricular bigeminy, ventricular tachycardia (VT), and ventricular fibrillation (VF) after BaCl2-injection as seen in rats. The ECG of mice developed ventricular bigeminy and VT after CaCl2 and AT after adrenaline i.p. injection. Additionally, acute cardiac arrhythmia after BaCl2 i.p. injection could be reverted by drugs (lidocaine and amiodarone) administration. Additionally, the different routes of administration for various chemical-induced arrhythmia in both mice and rats were also retrieved from PubMed and summarized. Comparing this approach with previous studies after the literature review reveals that arrhythmia of BaCl2-induced i.p. mice is compatible with the induction of other routes.

CONCLUSIONS

This study brings an alternative experimental model to investigate antiarrhythmic theories and provides a promising approach to discovering new interventions for acute arrhythmias.

In vitro identification of oridonin hybrids as potential anti-TNBC agents inducing cell cycle arrest and apoptosis by regulation of p21, γH2AX and cleaved PARP

TNBC has been recognized as the most highly aggressive breast cancer without chemotherapeutic drugs. A collection of oridonin hybrids consisting of conventional antitumor pharmacophores including nitrogen mustards and adamantane-1-carboxylic acid were synthesized by deletion or blockade of multiple hydroxyl groups and structural rearrangement. Compound 11a showed the most promising anti-TNBC activity with nearly 15-fold more potent antiproliferative effects than oridonin against MDA-MB-231 and HCC1806. Moreover, 11a significantly inhibited HCC1806, MDA-MB-231 and MDA-MB-468 cell proliferation by arresting cells at the G2/M phase in a dose-dependent manner. Furthermore, 11a could trigger dose-dependently early and late apoptosis in those indicated cell lines. More importantly, 11a could significantly increase p21, γH2AX and cleaved PARP accumulation in a dose-dependent manner. Furthermore, compound 11a exhibited better stability than oridonin in a plasma assay. Taken together, all results demonstrated that 11a may warrant further investigation as a promising anticancer drug candidate for the treatment of TNBC.

Precision Treatment of Anthracycline-Induced Cardiotoxicity: An Updated Review

OPINION STATEMENT

Anthracycline (ANT)-induced cardiotoxicity (AIC) is a particularly prominent form of cancer therapy-related cardiovascular toxicity leading to the limitations of ANTs in clinical practice. Even though AIC has drawn particular attention, the best way to treat it is remaining unclear. Updates to AIC therapy have been made possible by recent developments in research on the underlying processes of AIC. We review the current molecular pathways leading to AIC: 1) oxidative stress (OS) including enzymatic-induced and other mechanisms; 2) topoisomerase; 3) inflammatory response; 4) cardiac progenitor cell damage; 5) epigenetic changes; 6) renin-angiotensin-aldosterone system (RAAS) dysregulation. And we systematically discuss current prevention and treatment strategies and novel pathogenesis-based therapies for AIC: 1) dose reduction and change; 2) altering drug delivery methods; 3) antioxidants, dexrezosen, statina, RAAS inhibitors, and hypoglycemic drugs; 4) miRNA, natural phytochemicals, mesenchymal stem cells, and cardiac progenitor cells. We also offer a fresh perspective on the management of AIC by outlining the current dilemmas and challenges associated with its prevention and treatment.

Discovery of Loureirin analogues with colorectal cancer suppressive activity via regulating cell cycle and Fas death receptor

Chalcones and dihydrochalcones (DHCs) are important bioactive natural products (BNPs) isolated from traditional Chinese medicine. In this study, 13 chalcones were designed with the inspiration of Loureirin, a DHC extracted from Resina Draconis, and synthesized by classical Claisen-Schmidt reactions. Afterwards the reduction reactions were carried out to obtain the corresponding DHCs. Cytotoxicity assay indicated chalcones and DHCs possessed selective cytotoxicity against colorectal cancer (CRC) cells. The preliminary structure-activity relationships (SAR) of these compounds suggested the α, β-unsaturated ketone of the chalcones were crucial for the anticancer activity. Interestingly, compounds 3d and 4c exhibited selective anticancer activity against CRC cell line HCT116 with IC50s of 8.4 and 17.9 μM but not normal cell. Moreover, 4c could also inhibit the migration and invasion of CRC cells. Mechanism investigations showed 4c could induce cell cycle G2/M arrest by regulating cell cycle-associated proteins and could also up-regulate Fas cell surface death receptor. The virtual docking further pointed out that compounds 3d and 4c could nicely bind to the Fas/FADD death domain complex (ID: 3EZQ). Furthermore, silencing of Fas significantly enhanced the proliferation of CRC cells and attenuated the cytotoxicity induced by 4c. These results suggested 4c exerted its anticancer activity possibly regulating cell cycle and Fas death receptor. In summary, this study investigated the anticancer activity and mechanism of Loureirin analogues in CRC, suggesting these compounds may warrant further investigation as promising anticancer drug candidates for the treatment of CRC.

Identification of chalcone analogues as anti-inflammatory agents through the regulation of NF-κB and JNK activation

To develop new anti-inflammatory agents with improved pharmaceutical profiles, a series of chalcone analogues were designed and synthesized. In vitro anti-inflammatory activity of these compounds was evaluated by screening their inhibitory effects on NO production in RAW264.7 cell lines. The most promising compounds 3h and 3l were selected for further investigation by assessment of their dose-dependent inhibitory activity against cytokines such as TNF-α, IL-1β, and IL-6 and PGE2 release. The further study also indicated that 3h and 3l could significantly suppress the expression of iNOS and COX-2 through the NF-κB/JNK signaling pathway. Furthermore, compounds 3h and 3l could also remarkably inhibit the mRNA expression of inflammation-related genes. Meanwhile, 3h could also down-regulate ROS production. Docking simulation was conducted to position compounds 3h and 3l into the iNOS binding site to predict the probable binding mode. In conclusion, this series of chalcone analogues with reasonable drug-likeness obtained via in silico rapid prediction can be used as promising lead candidates.

Identification of isothiazolones analogues as potent bactericidal agents against antibiotic resistant CRE and MRSA strains

Carbapenem-resistant Enterobacterales (CRE) has emerged as a worldwide spread nosocomial superbug exhibiting antimicrobial resistance (AMR) to all current antibiotics, leaving limited options for treating its infection. To discovery novel antibiotics against CRE, we designed and synthesized a series of 14 isothiazol-3(2H)-one analogues subjected to antibacterial activity evaluation against Escherichia coli (E. coli) BL21 (NDM-1) and clinical strain E. coli HN88 for investigating their structure-activity relationships (SAR). The results suggested that 5-chloroisothiazolone core with an N-(4-chlorophenyl) substitution 5a was the most potent antibacterial activity against the E. coli BL21 (NDM-1) with MIC value of less than 0.032 μg/mL, which was at least 8000-fold higher than the positive control Meropenem (MRM). It also displayed 2048-fold potent than the positive control MRM against E. coli HN88. Additionally, SAR analysis supported the conclusion that compounds with a chloro-group substituted on the 5-position of the heterocyclic ring was much more potent than other positions. The board spectrum analysis suggested that compound 5a showed a promising antimicrobial activity on MRSA and CRE pathogens. Meanwhile, cytotoxicity study of compound 5a suggested that it had a therapeutic index value of 875, suggesting future therapeutic potential. In vivo efficacy study declared that compound 5a could also protect the BALB/c mice against American type culture collection (ATCC) 43,300. Further screening of our compounds against a collection of CRE strains isolated from patients indicated that compound 5 g displayed much stronger antibacterial activity compared with MRM. In conclusion, our studies indicated that isothiazolones analogues could be potent bactericidal agents against CRE and MRSA pathogens.