Ethanol potentiates mirtazapine-induced cardiotoxicity by inducing dysfunctional autophagy via HMGB1-dependent Akt/mTOR signaling pathway.

Previous surveys have revealed that mirtazapine (MIR), one of the most commonly prescribed antidepressants, is associated with a higher risk of adverse cardiac events compared with other newer antidepressants. Chronic ethanol (EtOH) abuse could also lead to myocardial injuries. Concerning the common comorbidity of major depression and alcohol dependence, combined consumption of MIR and EtOH might be prevalent in patients with depression, resulting in an additive or synergistic cardiotoxic effect. To this end, the present study evaluated cardiotoxicity induced by MIR-plus-EtOH in vivo (male C57BL/6J mice) and in vitro (H9c2 cardiomyoblasts), Further research on the role of autophagy and underlying signaling pathway were carried out in H9c2 cells. We found that EtOH exacerbated MIR-induced cardiotoxicity both in vivo and in vitro. Furthermore, EtOH significantly potentiated MIR-induced dysfunctional autophagy as reflected by upregulated protein levels of LC3-II, p62, Beclin1 and LAMP-1. Pharmacological inhibition of autophagy by 3-methyladenine alleviated MIR-plus-EtOH-induced myocardial injury. High mobility group box 1 (HMGB1) is a positive regulator of autophagy. In our work, HMGB1 knockdown decreased autophagosome accumulation and boosted viability in H9c2 cells. Additionally, HMGB1 blockage markedly upregulated p-Akt/Akt and p-mTOR/mTOR levels which were suppressed in MIR-plus-EtOH treated cells. In general, the present study demonstrates that EtOH potentiates MIR-induced cardiotoxicity which might be attributed to dysfunctional autophagy via inhibiting Akt/mTOR signaling pathway, while HMGB1 knockdown might contribute to improve autophagy flux.

Molecular Consequences of Depression Treatment: A Potential In Vitro Mechanism for Antidepressants-Induced Reprotoxic Side Effects.

The incidence of depression among humans is growing worldwide, and so is the use of antidepressants. However, our fundamental understanding regarding the mechanisms by which these drugs function and their off-target effects against human sexuality remains poorly defined. The present study aimed to determine their differential toxicity on mouse spermatogenic cells and provide mechanistic data of cell-specific response to antidepressant and neuroleptic drug treatment. To directly test reprotoxicity, the spermatogenic cells (GC-1 spg and GC-2 spd cells) were incubated for 48 and 96 h with amitriptyline (hydrochloride) (AMI), escitalopram (ESC), fluoxetine (hydrochloride) (FLU), imipramine (hydrochloride) (IMI), mirtazapine (MIR), olanzapine (OLZ), reboxetine (mesylate) (REB), and venlafaxine (hydrochloride) (VEN), and several cellular and biochemical features were assessed. Obtained results reveal that all investigated substances showed considerable reprotoxic potency leading to micronuclei formation, which, in turn, resulted in upregulation of telomeric binding factor (TRF1/TRF2) protein expression. The TRF-based response was strictly dependent on p53/p21 signaling and was followed by irreversible G2/M cell cycle arrest and finally initiation of apoptotic cell death. In conclusion, our findings suggest that antidepressants promote a telomere-focused DNA damage response in germ cell lines, which broadens the established view of antidepressants' and neuroleptic drugs' toxicity and points to the need for further research in this topic with the use of in vivo models and human samples.

Development of mirtazapine loaded solid lipid nanoparticles for topical delivery: Optimization, characterization and cytotoxicity evaluation.

Mirtazapine, an antidepressant drug has been proved to exert antipruritic effect upon oral administration in numerous clinical trial studies. The objective of the current study was to develop mirtazapine loaded solid lipid nanoparticles (SLNs) and evaluate its potential as a topical drug delivery system for management of pruritus. Mirtazapine loaded SLNs were successfully developed and optimized applying Box-Behnken design. The optimized mirtazapine loaded SLNs were characterized for physicochemical parameters and morphology. The in vitro cytotoxicity and cellular uptake studies of optimized SLNs were performed in human epithelial A-431 cell line. Further, the optimized mirtazapine loaded SLNs dispersion was incorporated into gel and characterized for rheology and texture analysis. The particle size and PDI of optimized mirtazapine loaded was found to be 180.3 nm and 0.209 respectively. The cytotoxicity studies revealed the safety of mirtazapine loaded SLNs on topical administration. The developed gel showed pseudoplastic flow behavior and good textural profile. The in vitro drug release studies showed that the developed mirtazapine loaded SLNs dispersion and its gel followed Korsmeyer-Peppas model (R2 = 0.905) and Higuchi model (R2 = 0.928) respectively. The ex vivo drug permeation studies showed higher values for mean cumulative amount of drug released (548.25 ± 29.29 µg/cm2), permeation flux (45.10 ± 0.78 µg/cm2/h) and skin retention (11.33 ± 0.85%) of SLNs gel in comparison to pure drug gel. The stability studies indicate the stability of SLNs gel for three months at refrigerated and ambient temperatures. Therefore, abovementioned findings suggest that mirtazapine loaded SLNs could be a potential system for topical management of pruritus.