Is cytochrome oxidase inhibition the primary mechanism in aluminum phosphide poisoning?

The possible therapeutic role of intravenous lipid emulsion in acute aluminium phosphide poisoning: a randomized controlled clinical trial

Introduction

Aluminum phosphide (ALP) is a highly toxic rodenticide and the mortality rates caused by it have been demonstrated up to 70-100% in various studies. Unfortunately, there is no specific antidote to manage its toxic effects. This study aimed to assess the biochemical and clinical efficacy and safety of intravenous lipid emulsion as an adjuvant therapy in acute aluminum phosphide poisoning.

Patients and methods

Sixty-four cases with acute ALP poisoning were stratified according to severity by the Poison Severity Score into severe and moderate groups (32 patients each). Patients were then randomly allocated into either receiving intravenous lipid emulsion in addition to the conventional treatment or receiving the conventional treatment only by using block randomization.

Results

Treatment by ILE resulted in a significant improvement in the survival time, the mean arterial blood pressure, arterial blood gases, and a significant reduction in serum lactate levels. The need for intubation and mechanical ventilation was insignificantly lower in the intervention groups compared to control groups. However, the reduction in mortality rate in the patients of intervention groups compared with control groups was found to be non-significant. Intravenous lipid emulsion use in acute ALP poisoning significantly prolonged the survival time, improved the metabolic acidosis, decreased the serum lactate levels and increased the mean arterial blood pressure and hospital stay in the intervention groups. And insignificantly decreased the mortality rate, need of intubation and mechanical ventilation, and the total dose of vasopressors.

Blocking vicious cycle of cardiac dysfunction by external cardiopulmonary resuscitation is the key to rescue acute aluminium phosphide poisoning

Aluminium phosphide (ALP) and aluminium zinc phosphide (ZnP), the two main ingredients of fumigation drugs, are commonly used to kill insects or rodents in grain. When exposed to water, highly toxic phosphine gas is released and absorbed through the respiratory or digestive tract. Phosphine gas could non-selectively block cytochrome oxidase, inhibit electron transfer and suppress oxidative phosphorylation, leading to cellular hypoxia and organ dysfunction. The characteristic clinical manifestations are refractory shock and metabolic acidosis with high mortality. However, patients with ALP poisoning have a chance to be cured. Here, we report a case of oral ALP poisoning that was successfully treated by extracorporeal membrane oxygenation (ECMO) combined with continuous renal replacement therapy (CRRT) during frequent ventricular fibrillation and cardiac dysfunction.

Recent Progress in Environmental Toxins-Induced Cardiotoxicity and Protective Potential of Natural Products

Humans are unconsciously exposed to environmental toxins including heavy metals as well as various pesticides, which have deleterious effects on human health. Accumulating studies pointed out that exposure to environmental toxins was associated with various cardiopathologic effects. This review summarizes the main mechanisms of cardiotoxicity induced by environmental toxins (cadmium, arsenic and pesticides) and discusses the potential preventive effects of natural products. These findings will provide a theoretical basis and novel agents for the prevention and treatment of environmental toxins-induced cardiotoxicity. Furthermore, the limitations of current studies, future needs and priorities are discussed.

Chrysin ameliorates aluminum phosphide-induced oxidative stress and mitochondrial damages in rat cardiomyocytes and isolated mitochondria

Apart from the anticancer, antioxidant, anti-inflammatory effects, and inhibition of aromatase, chrysin is involved in the protection of cardiovascular disorders. Cardiovascular complications are the main cause of death induced by aluminum phosphide (AlP) which is related to oxidative stress and mitochondrial damages. For this purpose, we investigated the effect of chrysin as an antioxidant and mitochondrial protective agent against AlP-induced toxicity in isolated cardiomyocytes and mitochondria obtained from rat heart ventricular. Using by biochemical and flow cytometry, cell viability, reactive oxygen species (ROS) formation, mitochondria membrane potential (MMP), lysosomal membrane integrity, malondialdehyde (MDA) content, and glutathione (GSH) and oxidized glutathione (GSSG) content were measured in isolated cardiomyocytes. Also, mitochondrial toxicity parameters such as mitochondrial NADH/succinate dehydrogenase activity, mitochondrial swelling, ROS formation, MMP collapse, and lipid peroxidation were analyzed in isolated mitochondria. Our results showed that the administration of chrysin (up to 10 μM) efficiently decreased (P < 0.05) cytotoxicity, oxidative, lysosomal, and mitochondrial damages induced by AlP, in isolated cardiomyocytes. Also, our finding in isolated mitochondria showed that chrysin (up to 10 μM) significantly (P < 0.05) decreased AlP-induced mitochondrial toxicity. These findings demonstrated that chrysin as an antioxidant and mitochondrial protective agent exert protective effect in wild-type cardiomyocyte treated with AlP. It was concluded that chrysin significantly reduced the toxicity of AlP in isolated cardiomyocytes and mitochondria. Due to the very low toxicity of chrysin for humans, it could be a promising agent in treatment of AlP poisoning.