Prophylactic efficacy of S-2(2-aminoethylamino)ethyl phenyl sulfide (DRDE-07) against sulfur mustard induced lung toxicity in mice

Oxidative Stress: An Intersection Between Radiation and Sulfur Mustard Lung Injury

Nuclear and chemical weapons of mass destruction share both a tragic and beneficial legacy in mankind's history and health. The horrific health effects of ionizing radiation and mustard gas exposures unleashed during disasters, wars, and conflicts have been harnessed to treat human health maladies. Both agents of destruction have been transformed into therapies to treat a wide range of cancers. The discovery of therapeutic uses of radiation and sulfur mustard was largely due to observations by clinicians treating victims of radiation and sulfur mustard gas exposures. Clinicians identified vulnerability of leukocytes to these agents and repurposed their use in the treatment of leukemias and lymphomas. Given the overlap in therapeutic modalities, it goes to reason that there may be common mechanisms to target as protective strategies against their damaging effects. This commentary will highlight oxidative stress as a common mechanism shared by both radiation and sulfur mustard gas exposures and discuss potential therapies targeting oxidative stress as medical countermeasures against the devastating lung diseases wrought by these agents.

Sesamin attenuates carrageenan-induced lung inflammation through upregulation of A20 and TAX1BP1 in rats

Sesamin is a major component in lignans of sesame seeds, has been described to possess a lot of biological activity. The main objective of our study was to investigate the inhibitory effect and novel molecular mechanisms of sesamin on carrageenan-induced lung inflammation in rats. Here we showed that sesamin can obviously reduce polymorphonuclear neutrophils infiltration and exudate volume. Further studies exhibited sesamin can inhibit cytokines release, polymorphonuclear neutrophils markers production and the degree of lung tissues injury. Western blot analysis revealed that sesamin can inhibit the TRAF6 expression and NF-κB pathway activation in lung tissue. We found that sesamin can increase the expression of A20 and TAX1BP1 in lung tissues, and the interaction between the two molecules. In conclusion, all these results demonstrated that sesamin can attenuate carrageenan-induced lung inflammation, the mechanisms that may be related to upregulation of the novel target A20 and TAX1BP1 which can negative regulation for NF-κB pathway. Importantly, this is the first evidence showing that TAX1BP1 can be as a novel regulatory target to attenuate the lung inflammation.

Pulmonary protective efficacy of S-2[2-aminoethylamino] ethyl phenyl sulphide (DRDE-07) and its analogues against sulfur mustard induced toxicity in mice

Our previous study showed that percutaneous sulfur mustard (SM) exposure induced pulmonary toxicity, which was attenuated by DRDE-07 (S-2[2-aminoethylamino] ethyl phenyl sulphide) pretreatment. The present study aimed to evaluate the protective efficacy of DRDE-07 and its analogues viz., DRDE-30 (S-2(2-aminoethyl amino)ethyl propyl sulphide) and DRDE-35 (S-2(2-aminoethyl amino)ethyl butyl sulphide) against SM. Thirty minutes before percutaneous SM (0.8 LD₅₀) exposure, female Swiss mice were orally gavaged with DRDE-07 and its analogues(0.2 LD₅₀). Animals were sacrificed on day 3 and 7, BAL fluid (BALF) and lung tissue were collected for biochemical, histopathological studies. As results, DRDE-07 and its analogues were beneficial in reducing the number of BALF inflammatory cells, protein level, lactate dehydrogenase (LDH) activity, myeloperoxidase (MPO) and β-glucuronidase activity, while content of BALF and lung reduced glutathione level (GSH) were significantly protected. The pretreatment of DRDE-07 and its analogues inhibited the recruitment of inflammatory cells into the lung. The beneficial effects of DRDE-07 and its analogues were attributed to their antioxidant and anti-inflammatory activity. Among the analogues, DRDE-30 exhibited significant beneficial effects as compared to the other two compounds. These analogues may be considered as prototype candidate molecules as there is no effective antidote for SM toxicity.

Long-term Respiratory Effects of Mustard Vesicants

Sulfur mustard and related vesicants are cytotoxic alkylating agents that cause severe damage to the respiratory tract. Injury is progressive leading, over time, to asthma, bronchitis, bronchiectasis, airway stenosis, and pulmonary fibrosis. As there are no specific therapeutics available for victims of mustard gas poisoning, current clinical treatments mostly provide only symptomatic relief. In this article, the long-term effects of mustards on the respiratory tract are described in humans and experimental animal models in an effort to define cellular and molecular mechanisms contributing to lung injury and disease pathogenesis. A better understanding of mechanisms underlying pulmonary toxicity induced by mustards may help in identifying potential targets for the development of effective clinical therapeutics aimed at mitigating their adverse effects.

Free Radical Production and Oxidative Stress in Lung Tissue of Patients Exposed to Sulfur Mustard: An Overview of Cellular and Molecular Mechanisms

Sulfur mustard (SM) is a chemical alkylating compound that primary targets lung tissue. It causes a wide variety of pathological effects in respiratory system such as chronic bronchitis, bronchiolitis obliterans, necrosis of the mucosa and inflammation, chronic obstructive pulmonary disease (COPD), and pulmonary fibrosis. However, molecular and cellular mechanisms for these pathologies are still unclear. Oxidative stress (OS) induced by reactive oxygen species (ROS) is likely a significant mechanism by which SM leads to cell death and tissues injury. SM can trigger various molecular and cellular pathways that are linked to ROS generation, OS, and inflammation. Hypoxia-induced oxidative stress, reduced activity of enzymatic antioxidants, depletion of intercellular glutathione (GSH), decreased productivity of GSH-dependent antioxidants, mitochondrial dysfunction, accumulation of leukocytes and proinflammatory cytokines, and increased expression of ROS producing-related enzymes and inflammatory mediators are the major events in which SM leads to massive production of ROS and OS in pulmonary system. Therefore, understanding of these molecules and signaling pathways gives us valuable information about toxicological effects of SM on injured tissues and the way for developing a suitable clinical treatment. In this review, we aim to discuss the possible mechanisms by which SM induces excessive production of ROS, OS, and antioxidants depletion in lung tissue of exposed patients.