Hesperidin neuroprotective effects against carbon monoxide-induced toxicity in male rats

Carbon monoxide (CO) is produced via incomplete combustion of fossil fuels and it may cause long-term neurological sequel upon exposure. Hesperidin (HES), a flavanone glycoside found in citrus plants, exerts diverse beneficial health effects. The present study mechanistically examined the neuroprotective effects of HES in CO-poisoned rats. Thirty male Wistar rats (five groups of six animals) were exposed to 3000 ppm CO for 1 h. Immediately after the exposure and on the next 4 consecutive days (totally five doses), rats intraperitoneally received either normal saline (the control group) or different doses of HES (25, 50, and 100 mg/kg). A sham group that was not exposed to CO was also considered. After evaluation of spatial learning and memory using a Morris water maze (MWM), animals were sacrificed and oxidative stress status in blood samples, and Akt, Bax, Bcl2, and brain-derived neurotrophic factor (BDNF) expression in brain samples were assessed. Western blot analysis indicated increased Akt but decreased Bax/Bcl2 levels in the HES 100 mg/kg, and induced BDNF levels in all HES-treated groups. MWM results showed that HES significantly decreased memory loss. The current findings indicate that HES could alleviate neurological impairments induced by CO in rats.

The effect of preconditioning agents on cardiotoxicity and neurotoxicity of carbon monoxide poisoning in animal studies: a systematic review

BACKGROUND

Carbon monoxide (CO) poisoning is a common intoxication and many people die yearly due to CO poisoning and preconditioning agents attenuate brain and cardiac injury caused by intoxication. It is critical to fully understand the efficacy of new methods to directly target the toxic effect of CO, such as conditioning agents, which are currently under development. This study aims to systematically investigate current evidence from animal experiments and the effects of administration preconditions in acute and late phases after CO poisoning on cardiotoxicity and neurotoxicity.

METHODS

Four databases (PubMed, Embase, Scopus, and Web of Science) were systematically searched without language restrictions, and hand searching was conducted until November 2021. We included studies that compare preconditioning agents with the control group after CO poisoning in animals. The SYRCLE RoB tool was used for risk of bias assessments.

RESULTS

Thirty-seven studies were included in the study. Erythropoietin, granulocyte colony-stimulating factor (GCSF), hydrogen-rich saline, and N-butylphthalide (NBP) were found to have positive effects on reducing neurotoxicity and cardiotoxicity. As other preconditions have fewer studies, no valuable results can be deduced. Most of the studies were unclear for sources of bias.

DISCUSSION

Administration of the examined preconditioning agents including NBP, hydrogen-rich saline, and GCSF in acute and late phases could attenuate neurotoxicity and cardiotoxicity of CO poisoned animals. For a better understanding of mechanisms and activities, and finding new and effective preconditioning agents, further preclinical and clinical studies should be performed to analyze the effects of preconditioning agents.

Ischemia reperfusion myocardium injuries in type 2 diabetic rats: Effects of ketamine and insulin on LC3-II and mTOR expression

Objectives: Myocardiopathy occurs in ischemia-induced injury caused by dysregulation of autophagy of cardiac tissues. The present report evaluates the protective effect of ketamine and insulin against myocardial injury in type 2 diabetic rats (T2DM).Methods: The effects of ketamine and its combination with insulin on biochemical parameters and inflammatory cytokines in the serum of I/R-induced myocardial injury in T2DM rats were evaluated. The parameters of reactive oxygen species and the expression of autophagosome signaling pathway proteins were also determined. Using transmission electron microscopy, we investigated autophagosomes. Western blots were used to detect autophagy-associated signaling pathways. Myocardial function was determined by echocardiography and histopathological changes in myocardial tissues were also determined in I/R-induced myocardial injury in type 2 diabetic rats.Results: There was a significant reduction in glucose, AST, LDH, and CK-MB levels and cytokines (IL-1β, IL-6, and TNF-α) in serum of the ketamine (p < .05) and ketamine + insulin (p < .01) groups than in the diabetic + I/R. MDA and ROS levels were reduced with a substantial (p < .05) increase in GSH levels through improved cardiac function in the ketamine (p < .05) and ketamine + insulin (p < .01) groups than the diabetic + I/R group. There was an increase in mature autophagosomes in diabetic+I/R+Kt+In compared to diabetic+I/R+Kt alone in infarction and marginal zones. It should be noted that the significant increase (p < .01) in protein levels of the autophagy-associated intracellular signaling pathways AMPK and mTOR, as well as an increase in LC3-II and BECLIN-1, suggests that ketamine combined with insulin-activated autophagy-associated intracellular signaling AMPK and mTOR.Conclusion: The findings of the study suggest that ketamine combined with insulin administration remarkably protects I/R-induced myocardial injury in rats with T2DM by reducing the dysregulation of autophagy.

Neuro-protective effects of n-butylphthalide on carbon monoxide poisoning rats by modulating IL-2, AKT and BCL-2

Acute carbon monoxide poisoning (CO-poisoning) causes neurotoxicity by inducing necrosis, apoptosis, lipid peroxidation, and oxidative stress. DL-3-n-butylphthalide (NBP) is a synthetic compound originally extracted from the seeds of Chinese celery and based on pure l-3-n-butylphthalide. In ischemia/reperfusion, it exerts neuroprotective effects through its anti-apoptotic, anti-necrotic and antioxidant properties, and activation of pro-survival pathways. Our study performed bioinformatic analysis to identify the differential expression genes. CO-poisoning patients' blood was collected to confirm the findings. Male rats were exposed to CO 3000 ppm for 40 min, and NBP (100 mg/kg/day) was continuously injected intraperitoneally immediately after poisoning and for the next 15 days. After NBP treatment, the rats were evaluated by Morris water maze test. At the end of experiments, blood and brain tissues of the rats were collected to evaluate the expression levels of IL-2, AKT and BCL-2. We found that IL-2 was elevated in CO-poisoning patients and animal models. Brain tissue damage in CO-poisoning rats was significantly alleviated after NBP treatment. Furthermore, NBP increased the expression of IL-2, AKT and BCL-2 in rat CO-poisoning model. NBP showed neuroprotective action by increasing IL-2, AKT, and BCL-2 expressions.

Repurposing FDA-approved drugs against the toxicity of platinum-based anticancer drugs

Platinum-based anticancer drugs (PADs), mainly cisplatin, carboplatin, and oxaliplatin, are widely used efficacious long-standing anticancer agents for treating several cancer types. However, clinicians worry about PAD chemotherapy and its induction of severe non-targeted organ toxicity. Compelling evidence has shown that toxicity of PAD on delicate body organs is associated with free radical generation, DNA impairment, endocrine and mitochondrial dysfunctions, oxidative inflammation, apoptosis, endoplasmic reticulum stress, and activation of regulator signaling proteins, cell cycle arrest, apoptosis, and pathways. The emerging trend is the repurposing of FDA-approved non-anticancer drugs (FNDs) for combating the side effects toxicity of PADs. Thus, this review chronicled the mechanistic preventive and therapeutic effects of FNDs against PAD organ toxicity in preclinical studies. FNDs are potential clinical drugs for the modulation of toxicity complications associated with PAD chemotherapy. Therefore, FNDs may be suggested as non-natural agent inhibitors of unpalatable side effects of PADs.

Endoplasmic reticulum stress in doxorubicin-induced cardiotoxicity may be therapeutically targeted by natural and chemical compounds: A review

Doxorubicin (DOX) is a chemotherapeutic agent with marked, dose-dependent cardiotoxicity that leads to tachycardia, atrial and ventricular arrhythmia, and irreversible heart failure. Induction of the endoplasmic reticulum (ER) which plays a major role in protein folding and calcium homeostasis was reported as a key contributor to cardiac complications of DOX. This article reviews several chemical compounds that have been shown to regulate DOX-induced inflammation, apoptosis, and autophagy via inhibition of ER stress signaling pathways, such as the IRE1α/ASK1/JNK, IRE1α/JNK/Beclin-1, and CHOP pathways.

Rosuvastatin and simvastatin attenuate cisplatin-induced cardiotoxicity via disruption of endoplasmic reticulum stress-mediated apoptotic death in rats: targeting ER-Chaperone GRP78 and Calpain-1 pathways

Cisplatin (CP) is a powerful antineoplastic chemotherapeutic agent with broad-spectrum properties. Acute and cumulative cardiotoxicity are major limiting factors for CP therapy. Various pathogenic pathways have been suggested to CP-induced cardiotoxicity; oxidative damage, ER stress, and programmed cell death/apoptosis. The present study aimed to assess the signaling mechanisms related to the advantageous effects of rosuvastatin (RSV) and simvastatin (SMV) against CP-related cardiac ER stress dependent apoptotic death in rats. Acute cardiotoxicity was induced by a single dose of CP (10 mg/kg, i.p.) on the 10th day of the experiment. RSV (10 mg/ kg/day) and SMV (10 mg/kg/day) were orally administered for 15 days. CP-treated rats showed significant alterations in electrocardiographic recordings and elevation in serum cardiac function biomarkers; troponin T content, lactate dehydrogenase and creatine kinase-MB levels as well as boost in the cardiac oxidative stress biomarkers. In addition, CP exposure resulted in GRP78 induction; an ER stress and elevation marker at calpain-1 content as well as activation of activated caspase-3 (ACASP3) and caspase-12 were reflected on CP-triggered apoptosis evidenced by elevation in the Bax/Bcl-2 ratio. However, RSV and SMV administration mitigate those adverse CP effects. Statins administration prominently alleviated CP-induced cardiac abnormalities exerting improvement in the ECG pattern and cardiac enzyme biomarkers. Interestingly, statins; RSV and SMV, disrupted CP-induced ER stress and the consequent apoptotic cell death evidenced by downregulation of ER-chaperone GRP78, calpain-1, ACASP3 and caspase-12 as well as decline in the Bax/Bcl-2 ratio. From all the previous findings, it can be suggested that statins namely; RSV and SMV, play protective role against CP-induced cardiac injury by regulating ER stress-mediated apoptotic pathways.

Carbon monoxide poisoning

Carbon monoxide (CO) is the leading cause of poisoning deaths in many countries, including Japan. Annually, CO poisoning claims about 2000-5000 lives in Japan, which is over half of the total number of poisoning deaths. This paper discusses the physicochemical properties of CO and the toxicological evaluation of CO poisoning.

Magnesium sulfate ameliorates carbon monoxide‑induced cerebral injury in male rats

Carbon monoxide (CO) has been shown to induce several cardiovascular abnormalities, as well as necrosis, apoptosis and oxidative stress in the brain. Magnesium sulfate (MS) has been shown to have beneficial activities against hypoxia in the brain. In the present study, the possible protective effects of MS against CO‑induced cerebral ischemia were investigated. For this purpose, 25 male Wistar rats were exposed to 3,000 ppm CO for 1 h. The animals were divided into 5 groups (n=5 in each group) as follows: The negative control group (not exposed to CO), the positive control group (CO exposed and treated with normal saline), and 3 groups of CO‑exposed rats treated with MS (75, 150 and 300 mg/kg/day) administered intraperitoneally for 5 consecutive days. On the 5th day, the animals were sacrificed and the brains were harvested for the evaluation of necrosis, apoptosis and oxidative stress. Histopathological evaluation revealed that MS reduced the number and intensity of necrotic insults. The Bax/Bcl2 ratio and malondialdehyde (MDA) levels were significantly decreased in a dose‑dependent manner in the MS‑treated rats compared to the positive control group, while a significant dose‑dependent increase in Akt expression, a pro‑survival protein, was observed. In addition, MS administration reduced pro‑apoptotic indice levels, ameliorated histological insults, favorably modulated oxidative status and increased Akt expression levels, indicating a possible neuroprotective effect in the case of CO poisoning. On the whole, the findings of this study indicate that MS may prove to be useful in protecting against CO‑induced cerebral injury.