Cardiotoxicity of methamphetamine under stress conditions: Comparison of single dose and long-term use

Ferulic acid protects against stress-induced myocardial injury in mice

Excessive stress is a known contributor to cardiovascular diseases (CVD), and ferulic acid (FA), a natural phenolic compound, has demonstrated significant antioxidant and anti-inflammatory properties. This study investigates the protective effects of FA against stress-induced myocardial injury (SIMI) and elucidates the underlying mechanisms. An acute SIMI model was established in mice using low-temperature water immersion restraint. Cardiac function was assessed via cardiac index and histopathological analysis. Serum levels of corticosterone (CORT), lactate dehydrogenase (LDH), and brain natriuretic peptide (BNP) were quantified using enzyme-linked immunosorbent assay (ELISA), along with inflammatory markers TNF-α and IL-1β. The oxidative stress parameters, including malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), and reactive oxygen species (ROS), were analyzed using colorimetric methods and fluorescent probes. Immunohistochemistry (IHC) and Western Blot were used to analyze the expression of proteins related to TNF, MAPK, PPAR-α/PGC-1α, and Nrf2 signaling pathways. Results indicated that FA pretreatment improved cardiac index, myocardial structural integrity, and reduced inflammatory cell infiltration. Serum levels of LDH, BNP, CORT, TNF-α, and IL-1β were significantly decreased in FA-treated SIMI mice. Elevated MDA and ROS levels, along with decreased GSH and SOD levels in the SIMI group, were reversed by FA pretreatment, likely through activation of the PPARα/PGC-1α and Nrf2 signaling pathways. Additionally, FA inhibited the TNF-α/TNFR1 and ERK/JNK MAPK pathways, contributing to its protective effects. In conclusion, FA mitigates SIMI by alleviating oxidative stress and inflammatory responses.

Methamphetamine induces cardiomyopathy through GATA4/NF-κB/SASP axis-mediated cellular senescence

With the world pandemic of methamphetamine (METH), METH-associated cardiomyopathy (MAC) has become a widespread epidemic and is also recognized as a cause of heart failure in young people. The mechanism of occurrence and development of MAC is not clear. In this study, firstly, the animal model was evaluated by echocardiography and myocardial pathological staining. The results revealed that the animal model exhibited cardiac injury consistent with clinical alterations of MAC, and the mice developed cardiac hypertrophy and fibrosis remodeling, which led to systolic dysfunction and left ventricular ejection fraction (%LVEF) < 40%. The expression of cellular senescence marker proteins (p16 and p21) and senescence-associated secretory phenotype (SASP) was significantly increased in mouse myocardial tissue. Secondly, mRNA sequencing analysis of cardiac tissues revealed the key molecule GATA4, and Western blot, qPCR and immunofluorescence results showed that the expression level of GATA4 was significantly increased after METH exposure. Finally, knockdown of GATA4 expression in H9C2 cells in vitro significantly attenuated METH-induced cardiomyocyte senescence. Consequently, METH causes cardiomyopathy through cellular senescence mediated by the GATA4/NF-κB/SASP axis, which is a feasible target for the treatment of MAC.

Toxic Effects of Methamphetamine on Perivascular Health: Co-morbid Effects of Stress and Alcohol Use Disorders

Methamphetamine (Meth) abuse presents a global problem and commonly occurs with stress and/or alcohol use disorders. Regardless, the biological causes and consequences of these comorbidities are unclear. Whereas the mechanisms of Meth, stress, and alcohol abuse have been examined individually and well-characterized, these processes overlap significantly and can impact the neural and peripheral consequences of Meth. This review focuses on the deleterious cardio- and cerebrovascular effects of Meth, stress, alcohol abuse, and their comorbid effects on the brain and periphery. Points of emphasis are on the composition of the blood-brain barrier and their effects on the heart and vasculature. The autonomic nervous system, inflammation, and oxidative stress are specifically highlighted as common mediators of the toxic consequences to vascular and perivascular health. A significant portion of the Meth abusing population also presents with stress and alcohol use disorders, prompting a need to understand the mechanisms underlying their comorbidities. Little is known about their possible convergent effects. Therefore, the purpose of this critical review is to identify shared mechanisms of Meth, chronic stress, and alcohol abuse that contributes to the dysfunction of vascular health and underscores the need for studies that directly address their interactions.

Methamphetamine administration increases hepatic CYP1A2 but not CYP3A activity in female guinea pigs

Methamphetamine use has increased over the past decade and the first use of methamphetamine is most often when women are of reproductive age. Methamphetamine accumulates in the liver; however, little is known about the effect of methamphetamine use on hepatic drug metabolism. Methamphetamine was administered on 3 occassions to female Dunkin Hartley guinea pigs of reproductive age, mimicking recreational drug use. Low doses of test drugs caffeine and midazolam were administered after the third dose of methamphetamine to assess the functional activity of cytochrome P450 1A2 and 3A, respectively. Real-time quantitative polymerase chain reaction was used to quantify the mRNA expression of factors involved in glucocorticoid signalling, inflammation, oxidative stress and drug transporters. This study showed that methamphetamine administration decreased hepatic CYP1A2 mRNA expression, but increased CYP1A2 enzyme activity. Methamphetamine had no effect on CYP3A enzyme activity. In addition, we found that methamphetamine may also result in changes in glucocorticoid bioavailability, as we found a decrease in 11β-hydroxysteroid dehydrogenase 1 mRNA expression, which converts inactive cortisone into active cortisol. This study has shown that methamphetamine administration has the potential to alter drug metabolism via the CYP1A2 metabolic pathway in female guinea pigs. This may have clinical implications for drug dosing in female methamphetamine users of reproductive age.

Neuronal and peripheral damages induced by synthetic psychoactive substances: an update of recent findings from human and animal studies

Preclinical and clinical studies indicate that synthetic psychoactive substances, in addition to having abuse potential, may elicit toxic effects of varying severity at the peripheral and central levels. Nowadays, toxicity induced by synthetic psychoactive substances poses a serious harm for health, since recreational use of these substances is on the rise among young and adult people. The present review summarizes recent findings on the peripheral and central toxicity elicited by “old” and “new” synthetic psychoactive substances in humans and experimental animals, focusing on amphetamine derivatives, hallucinogen and dissociative drugs and synthetic cannabinoids.

DNA damage-inducible transcript 4 (DDIT4) mediates methamphetamine-induced autophagy and apoptosis through mTOR signaling pathway in cardiomyocytes

Methamphetamine (METH) is an amphetamine-like psychostimulant that is commonly abused. Previous studies have shown that METH can induce damages to the nervous system and recent studies suggest that METH can also cause adverse and potentially lethal effects on the cardiovascular system. Recently, we demonstrated that DNA damage-inducible transcript 4 (DDIT4) regulates METH-induced neurotoxicity. However, the role of DDIT4 in METH-induced cardiotoxicity remains unknown. We hypothesized that DDIT4 may mediate METH-induced autophagy and apoptosis in cardiomyocytes. To test the hypothesis, we examined DDIT4 protein expression in cardiomyocytes and in heart tissues of rats exposed to METH with Western blotting. We also determined the effects on METH-induced autophagy and apoptosis after silencing DDIT4 expression with synthetic siRNA with or without pretreatment of a mTOR inhibitor rapamycin in cardiomyocytes using Western blot analysis, fluorescence microscopy and TUNEL staining. Our results showed that METH exposure increased DDIT4 expression and decreased phosphorylation of mTOR that was accompanied with increased autophagy and apoptosis both in vitro and in vivo. These effects were normalized after silencing DDIT4. On the other hand, rapamycin promoted METH-induced autophagy and apoptosis in DDIT4 knockdown cardiomyocytes. These results suggest that DDIT4 mediates METH-induced autophagy and apoptosis through mTOR signaling pathway in cardiomyocytes.