dl-α-lipoic acid ameliorates cyclophosphamide induced cardiac mitochondrial injury

Cardiotoxicity in autologous haematopoietic stem cell transplantation for systemic sclerosis

Autologous haematopoietic stem cell transplantation is now well-established as an effective treatment for severe systemic sclerosis with clear demonstration of favourable end-organ and survival outcomes. Treatment-related cardiotoxicity remains the predominant safety concern and contraindicates autologous haematopoietic stem cell transplantation in patients with severe cardiopulmonary disease. In this review, we describe the cardiovascular outcomes of autologous haematopoietic stem cell transplantation recipients, discuss the potential mechanisms of cardiotoxicity and propose future mitigating strategies.

Assessing Drug-Induced Mitochondrial Toxicity in Cardiomyocytes: Implications for Preclinical Cardiac Safety Evaluation

Drug-induced cardiotoxicity not only leads to the attrition of drugs during development, but also contributes to the high morbidity and mortality rates of cardiovascular diseases. Comprehensive testing for proarrhythmic risks of drugs has been applied in preclinical cardiac safety assessment for over 15 years. However, other mechanisms of cardiac toxicity have not received such attention. Of them, mitochondrial impairment is a common form of cardiotoxicity and is known to account for over half of cardiovascular adverse-event-related black box warnings imposed by the U.S. Food and Drug Administration. Although it has been studied in great depth, mitochondrial toxicity assessment has not yet been incorporated into routine safety tests for cardiotoxicity at the preclinical stage. This review discusses the main characteristics of mitochondria in cardiomyocytes, drug-induced mitochondrial toxicities, and high-throughput screening strategies for cardiomyocytes, as well as their proposed integration into preclinical safety pharmacology. We emphasize the advantages of using adult human primary cardiomyocytes for the evaluation of mitochondrial morphology and function, and the need for a novel cardiac safety testing platform integrating mitochondrial toxicity and proarrhythmic risk assessments in cardiac safety evaluation.

The Role of METTL3-Mediated N6-Methyladenosine (m6A) of JPH2 mRNA in Cyclophosphamide-Induced Cardiotoxicity

Cyclophosphamide (CYP)-induced cardiotoxicity is a common side effect of cancer treatment. Although it has received significant attention, the related mechanisms of CYP-induced cardiotoxicity remain largely unknown. In this study, we used cell and animal models to investigate the effect of CYP on cardiomyocytes. Our data demonstrated that CYP-induced a prolonged cardiac QT interval and electromechanical coupling time courses accompanied by JPH2 downregulation. Moreover, N6-methyladenosine (m6A) methylation sequencing and RNA sequencing suggested that CYP induced cardiotoxicity by dysregulating calcium signaling. Importantly, our results demonstrated that CYP induced an increase in the m6A level of JPH2 mRNA by upregulating methyltransferases METTL3, leading to the reduction of JPH2 expression levels, as well as increased field potential duration and action potential duration in cardiomyocytes. Our results revealed a novel mechanism for m6A methylation-dependent regulation of JPH2, which provides new strategies for the treatment and prevention of CYP-induced cardiotoxicity.

Effects of anticancer drugs on the cardiac mitochondrial toxicity and their underlying mechanisms for novel cardiac protective strategies

Mitochondria are organelles that play a pivotal role in the production of energy in cells, and vital to the maintenance of cellular homeostasis due to the regulation of many biochemical processes. The heart contains a lot of mitochondria because those muscles require a lot of energy to keep supplying blood through the circulatory system, implying that the energy generated from mitochondria is highly dependent. Thus, cardiomyocytes are sensitive to mitochondrial dysfunction and are likely to be targeted by mitochondrial toxic drugs. It has been reported that some anticancer drugs caused unwanted toxicity to mitochondria. Mitochondrial dysfunction is related to aging and the onset of many diseases, such as obesity, diabetes, cancer, cardiovascular and neurodegenerative diseases. Mitochondrial toxic mechanisms can be mainly explained concerning reactive oxygen species (ROS)/redox status, calcium homeostasis, and endoplasmic reticulum stress (ER) stress signaling. The toxic mechanisms of many anticancer drugs have been revealed, but more studying and understanding of the mechanisms of drug-induced mitochondrial toxicity is required to develop mitochondrial toxicity screening system as well as novel cardioprotective strategies for the prevention of cardiac disorders of drugs. This review focuses on the cardiac mitochondrial toxicity of commonly used anticancer drugs, i.e., doxorubicin, mitoxantrone, cisplatin, arsenic trioxide, and cyclophosphamide, and their possible chemopreventive agents that can prevent or alleviate cardiac mitochondrial toxicity.

Cardioprotective Effect of Crude Extract and Solvent Fractions of Urtica simensis Leaves on Cyclophosphamide-Induced Myocardial Injury in Rats

Background

Globally, cardiovascular diseases (CVDs) are becoming the major cause of death. Urtica simensis is one of endogenous plant which treats a wide range of disease conditions including heart diseases. However, there is limited information on safety and efficacy of the plant.

Objective

To evaluate the in vitro antioxidant, the in vivo cardioprotective activity of crude extract and solvent fractions of Urtica simensis leaves on cyclophosphamide-induced myocardial injury.

Methods

The cardioprotective activity of the crude extract, aqueous and hexane fraction of Urtica simensis leaves was evaluated based on anatomical, biochemical and histopathological methods. The in vitro antioxidant activity of the plant was also assayed in terms of free radical scavenging activity (RSA).

Results

Crude extract and solvent fractions of Urtica simensis significantly prevented the deleterious effect of cyclophosphamide on body weight (P<0.001), heart weight to body ratio (P<0.01), cardiac biomarkers including troponin I (P<0.01), alanine transaminase (ALT) (P<0.001), aspartate aminotransferase (AST) (P<0.01) and lipid profiles including triglycerides (P<0.001) and total cholesterol (P<0.01). The histopathological study confirmed presence of necrosis, oedema and haemorrhage on cyclophosphamide alone-treated groups while the 200mg/kg and 400mg/kg of the crude extract and aqueous fraction showed normal cardiocytes. The antioxidant assay of Urtica simensis plant exhibited free radical scavenging activity of inhibitory concentration of 50% (IC₅₀) for the crude extract with the values of 63.27µg/mL, aqueous fraction with the values of 136.38µg/mL and hexane fraction with the values of 258.70µg/mL.

Conclusion

Crude extract and solvent fractions of Urtica simensis leaves have cardioprotective activities. The cardioprotective effect could be attributed to the antioxidant activity of the plant extracts. However, this requires further in-depth understanding.

Cardioprotective Effect of Croton macrostachyus Stem Bark Extract and Solvent Fractions on Cyclophosphamide-Induced Cardiotoxicity in Rats

Objective

To evaluate the antioxidant and cardioprotective activities of stem bark extract and solvent fractions of Croton macrostachyus on cyclophosphamide-induced cardiotoxicity in rats. Materials and Methods. DPPH free radical scavenging assay method was used to determine antioxidant activity whereas Sprague-Dawley rats were used to evaluate the cardioprotective activity. Except for the normal control, all groups were subjected to cyclophosphamide (200 mg/kg, i.p.) toxicity on the first day. Enalapril at 10 mg/kg was used as a reference. The hydromethanolic crude extract (100, 200, and 400 mg/kg) and aqueous and ethyl acetate fractions (100 and 200 mg/kg, each) were administered for 10 days. The cardioprotective activities were evaluated using cardiac biomarkers such as Troponin I, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), total cholesterol (TC), triglyceride (TG), and histopathological studies of heart tissue.

Results

Crude extract and ethyl acetate and aqueous fractions exhibited free radical scavenging activities at IC₅₀ of 594 μg/mL, 419 μg/mL, and 716 μg/mL, respectively. Crude extract at 400 mg/kg decreased the levels of troponin, AST, ALT, and ALP to 0.29 ± 0.06 ng/mL, 103.00 ± 7.63 U/L, 99.80 ± 6.18 U/L, and 108.80 ± 8.81 U/L, respectively. In addition, ethyl acetate fraction at 200 mg/kg decreased the levels of troponin, AST, ALT, and ALP to 0.22 ± 0.02 ng/mL, 137.00 ± 14.30 U/L, 90.33 ± 6.13 U/L, and 166.67 ± 13.50 U/L, respectively, compared with the cyclophosphamide control group.

Conclusions

Croton macrostachyus possesses cardioprotective activities and it could be a possible source of treatment for cardiotoxicity induced by cyclophosphamide.

Cyclophosphamide and regional citrate anticoagulation: A sour combination?

We present a case of a woman in her 70 s, on cyclophosphamide for multiple myeloma, who was admitted to critical care with grade III acute kidney injury. Renal replacement therapy with regional citrate anticoagulation was commenced. Shortly thereafter her systemic-ionised calcium levels fell and remained stubbornly low until post-filter calcium return was doubled. Her total-to-ionised calcium ratio gradually increased and so, to avoid further accumulation of citrate, anticoagulation was changed to heparin. Cyclophosphamide, which accumulates in renal failure, is known to interfere with key enzymes involved in the tricarboxylic acid cycle. We postulate that cyclophosphamide interfered with her citrate metabolism, resulting in persistent systemic chelation of calcium.

Cardioprotective Effect of Selenium Against Cyclophosphamide-Induced Cardiotoxicity in Rats

The objective of this study is to evaluate the possible protective effects of selenium (Se) against cyclophosphamide (CP)-induced acute cardiotoxicity in rats. A total of 42 male Spraque-Dawley rats were divided into six groups (n = 7). Rats in the first group were served as control. Rats in the second group received CP (150 mg/kg) at the sixth day of experiment. Animals in the third and fourth groups were treated with only 0.5 and 1 mg/kg Se respectively for six consecutive days. Rats in the fifth and sixth groups received respective Se doses (0.5 or 1 mg/kg) for 6 days and then a single dose of CP administered on the sixth day. On day 7, the animals were sacrificed; blood samples were collected to measure malondialdehyde (MDA), glutathione (GSH), lactate dehydrogenase (LDH), creatine kinase-MB (CK-MB), and ischemia-modified albumin (IMA) levels. Heart tissues were processed routinely and tissue sections were stained with H + E for light microscopic examination. In the CP-treated rats MDA, LDH, CK-MB, and IMA serum levels increased, while GSH levels decreased. Microscopic evaluation showed that tissue damage was conspicuously lower in CP plus Se groups. Moreover, 1 mg/kg Se was more protective than 0.5 mg/kg Se as indicated by histopathological and biochemical values. In conclusion, Se is suggested to be a potential candidate to ameliorate CP-induced cardiotoxicity which may be related to its antioxidant activity.

Robinin modulates doxorubicin-induced cardiac apoptosis by TGF-β1 signaling pathway in Sprague Dawley rats

The study focussed on the cardioprotective effect of robinin on doxorubicin-induced cardio-toxicity in Sprague Dawley rats. After the experimental period, animals were sacrificed and the various parameters such as cardiac markers, toxicity parameters, antioxidant status, ROS generation, lipid peroxidation status and inflammatory parameters were assessed. Gene expression study by RT-PCR analysis and proteins expression study by western blotting were done. Doxorubicin causes significant increase in the levels of cardiac marker enzymes, namely lactate dehydrogenase (LDH), creatine phospokinase (CPK), toxicity parameters like serum glutamate oxaloacetate transaminase (SGOT) and serum glutamate pyruvate transaminase (SGPT). Antioxidant enzyme levels were decreased; lipid peroxidation products in heart tissue and inflammatory markers, namely cyclooxygenase (COX2) and lipooxygenase (LOX15) were significantly increased. Gene expression study by RT-PCR analysis of transforming growth factor-β1 (TGF-β1), Smad2, murine double minute (Mdm2), Smad3, cyclin-dependent kinase inhibitor 2A (CDKN2A), Smad4 and Smad7 were significantly altered. The western blotting study of p53, Bcl-2 and Bax also showed altered expression. The supplementation of the Robinin along with DOX caused normalised level of all the above parameters and cardio-toxicity. This study revealed the cardioprotective nature of Robinin on doxorubicin-induced cardiac toxicity by modulating TGF-β1 signaling pathway in Sprague Dawley rats.

Cardioprotective effect of Saraca indica against cyclophosphamide induced cardiotoxicity in rats: a biochemical, electrocardiographic and histopathological study

Objectives:

Cardioprotective activity of alcoholic extract of Saraca indica (SI) bark was investigated against cyclophosphamide induced cardiotoxicity.

Materials and Methods:

Cardiotoxicity was induced in Wistar rats by administering cyclophosphamide (200 mg/kg, i.p.) single injection on first day of experimental period. Saraca indica (200 and 400 mg/kg, p.o.) was administered immediately after administration of cyclophosphamide on first day and daily for 10 days. The general observations and mortality were measured.

Results:

Cyclophosphamide administration significantly (p < 0.05) increased lipid peroxidation (LPO) and decreased the levels of antioxidant markers such as reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT). Cyclophosphamide elevated the levels of biomarker enzymes like creatine kinase (CK), creatine kinase isoenzyme MB (CK-MB), lactate dehydrogenase (LDH), aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP). Further, the cyclophosphamide treated rats showed changes in electrocardiogram (ECG) along with increased levels of cholesterol and triglycerides. Treatment with Saraca indica significantly (p < 0.05) reversed the status of cardiac biomarkers, ECG, oxidative enzymes and lipid profile in cyclophosphamide induced cardiotoxicity. Potential cardioprotective effect of Saraca indica was supported by histopathological examination that reduced severity of cellular damage of the myocardium.

Conclusion:

The biochemical, ECG and histopathology reports support the cardioprotective effect of Saraca indica which could be attributed to antioxidant activity.

Thymoquinone supplementation attenuates cyclophosphamide-induced cardiotoxicity in rats

This study examined the possible protective effects of thymoquinone (TQ), the main constituent of the volatile oil of black seed (Nigella sativa), against cyclophosphamide (CP)-induced cardiotoxicity. Adult male Wistar albino rats were divided into four treatment groups. Rats in the first group were served as control. Rats in the second group received TQ (50 mg/L in drinking water) for 12 days. Animals in the third group were injected with a single dose of CP (200 mg/kg, IP) at day 5. Rats in the fourth group received TQ (50 mg/L in drinking water) for 5 days before a single dose of CP (200 mg/kg, IP) and continued thereafter throughout the experiment. On day 13, animals were sacrificed; serum and hearts were isolated and analyzed. Cyclophosphamide resulted in a significant increase in serum creatine kinase, lactate dehydrogenase, cholesterol, triglycerides, creatinine, urea, and tumor necrosis factor-α. In heart tissues, CP resulted in a significant increase in thiobarbituric acid reactive substances and total nitrate/nitrite and a significant decrease in reduced glutathione, glutathione peroxidase, catalase, and adenosine triphosphate levels. Interestingly, TQ supplementation resulted in a complete reversal of all the biochemical changes induced by CP to their control values. Data from this study suggest that TQ supplementation attenuates CP-induced cardiotoxicity by a mechanism related, at least in part, to its ability to decrease oxidative and nitrosative stress and to preserve the activity of antioxidant enzymes as well as its ability to improve the mitochondrial function and energy production. .

Is it time to reassess alpha lipoic acid and niacinamide therapy in schizophrenia?

As sulfur containing thiols, alpha lipoic acid (ALA) and its reduced form dihydrolipoic acid (DHLA) are powerful antioxidants and free radical scavengers capable of performing many of the same functions as glutathione (GSH). ALA supplementation may help protect mitochondria from oxidative stress, a possible mechanism contributing to certain forms of brain diseases called schizophrenia. Shortly before the advent of antipsychotic medications, two small studies found ALA relieved psychiatric symptoms in schizophrenia. More recently, animal studies have shown ALA augmentation improves mitochondrial function. At pharmaceutical levels, niacinamide helps preserve mitochondrial membrane integrity and acts as an antioxidant. ALA is a precursor for lipoamide, an essential mitochondrial coenzyme and niacinamide is a component of niacinamide adenine dinucleotide (NAD). NADH, the reduced form of NAD, is involved in the reduction of ALA to DHLA within the mitochondria. This is relevant to contemporary research because DHLA increases GSH and low GSH levels contribute to mitochondrial dysfunction and oxidative stress which have been implicated in the pathophysiology of schizophrenia.