Radioprotective effect of diethylcarbamazine on radiation-induced acute lung injury and oxidative stress in mice

Mitochondria Energy Metabolism Depression as Novel Adjuvant to Sensitize Radiotherapy and Inhibit Radiation Induced-Pulmonary Fibrosis

Currently, the typical combination therapy of programmed death ligand-1 (PD-L1) antibodies with radiotherapy (RT) still exhibits impaired immunogenic antitumor response in clinical due to lessened DNA damage and acquired immune tolerance via the upregulation of some other immune checkpoint inhibitors. Apart from this, such combination therapy may raise the occurrence rate of radiation-induced lung fibrosis (RIPF) due to enhanced systemic inflammation, leading to the ultimate death of cancer patients (average survival time of about 3 years). Therefore, it is newly revealed that mitochondria energy metabolism regulation can be used as a novel effective PD-L1 and transforming growth factor-β (TGF-β) dual-downregulation method. Following this, IR-TAM is prepared by conjugating mitochondria-targeted heptamethine cyanine dye IR-68 with oxidative phosphorylation (OXPHOS) inhibitor Tamoxifen (TAM), which then self-assembled with albumin (Alb) to form IR-TAM@Alb nanoparticles. By doing this, tumor-targeting IR-TAM@Alb nanoparticle effectively reversed tumor hypoxia and depressed PD-L1 and TGF-β expression to sensitize RT. Meanwhile, due to the capacity of heptamethine cyanine dye in targeting RIPF and the function of TAM in depressing TGF-β, IR-TAM@Alb also ameliorated fibrosis development induced by RT.

Radioprotective Effect of Piperine, as a Major Component of Black Pepper, Against Radiation-induced Colon Injury: Biochemical and Histological Studies

BACKGROUND

Patients undergoing radiotherapy are prone to radiation-induced gastrointestinal injury. Piperine is an alkaloid component in black pepper with a unique chemopreventive activity against oxidative stress-related damage in healthy tissues. The purpose of this study was to investigate the effects of piperine on intestinal damage.

METHODS

In this study, mice were divided into eight groups: including the control, piperine (10, 25, and 50 mg/kg), radiation (6 Gy), and piperine+radiation (10, 25 and 50 mg/kg + 6 Gy) groups. The radioprotective effects of piperine were evaluated by biochemical (MDA, GSH, and PC) and histopathological assessments in colon tissues.

RESULTS

The 10 mg/kg dose of piperine significantly reduced the levels of oxidative stress biomarkers compared to the group that received only radiation. In addition, pre-treatment with 10 mg/kg piperine diminished the histopathological changes like vascular congestion in the submucosa, while the dose of 50 mg/kg led to the infiltration of inflammatory cells.

CONCLUSION

Based on this study, it is concluded that piperine, at low dose, with its antioxidant properties, could reduce the colon damage caused by radiation.

Crosstalk between Oxidative Stress and Inflammation Induced by Ionizing Radiation in Healthy and Cancerous Cells

Radiotherapy (RT) is a unique modality in cancer treatment with no replacement in many cases and uses a tumoricidal dose of various ionizing radiation (IR) types to kill cancer cells. It causes oxidative stress through reactive oxygen species (ROS) production or the destruction of antioxidant systems. On the other hand, RT stimulates the immune system both directly and indirectly by releasing danger signals from stress-exposed and dying cells. Oxidative stress and inflammation are two reciprocal and closely related mechanisms, one induced and involved by the other. ROS regulates the intracellular signal transduction pathways, which participate in the activation and expression of pro-inflammatory genes. Reciprocally, inflammatory cells release ROS and immune system mediators during the inflammation process, which drive the induction of oxidative stress. Oxidative stress or inflammation-induced damages can result in cell death (CD) or survival mechanisms that may be destructive for normal cells or beneficial for cancerous cells. The present study has focused on the radioprotection of those agents with binary effects of antioxidant and anti-inflammatory mechanisms IR-induced CD.

Development of radiation countermeasure agents for acute radiation syndromes

The risk of internal and external exposure to ionizing radiation (IR) has increased alongside the development and implementation of nuclear technology. Therefore, serious security issues have emerged globally, and there has been an increase in the number of studies focusing on radiological prevention and medical countermeasures. Radioprotective drugs are particularly important components of emergency medical preparedness strategies for the clinical management of IR-induced injuries. However, a few drugs have been approved to date to treat such injuries, and the related mechanisms are not entirely understood. Thus, the aim of the present review was to provide a brief overview of the World Health Organization's updated list of essential medicines for 2023 for the proper management of national stockpiles and the treatment of radiological emergencies. This review also discusses the types of radiation-induced health injuries and the related mechanisms, as well as the development of various radioprotective agents, including Chinese herbal medicines, for which significant survival benefits have been demonstrated in animal models of acute radiation syndrome.

Redox Interactions in Chemo/Radiation Therapy-induced Lung Toxicity; Mechanisms and Therapy Perspectives

Lung toxicity is a key limiting factor for cancer therapy, especially lung, breast, and esophageal malignancies. Radiotherapy for chest and breast malignancies can cause lung injury. However, systemic cancer therapy with chemotherapy may also induce lung pneumonitis and fibrosis. Radiotherapy produces reactive oxygen species (ROS) directly via interacting with water molecules within cells. However, radiation and other therapy modalities may induce the endogenous generation of ROS and nitric oxide (NO) by immune cells and some nonimmune cells such as fibroblasts and endothelial cells. There are several ROS generating enzymes within lung tissue. NADPH Oxidase enzymes, cyclooxygenase-2 (COX-2), dual oxidases (DUOX1 and DUOX2), and the cellular respiratory system in the mitochondria are the main sources of ROS production following exposure of the lung to anticancer agents. Furthermore, inducible nitric oxide synthase (iNOS) has a key role in the generation of NO following radiotherapy or chemotherapy. Continuous generation of ROS and NO by endothelial cells, fibroblasts, macrophages, and lymphocytes causes apoptosis, necrosis, and senescence, which lead to the release of inflammatory and pro-fibrosis cytokines. This review discusses the cellular and molecular mechanisms of redox-induced lung injury following cancer therapy and proposes some targets and perspectives to alleviate lung toxicity.

Efficacy and Safety of Diethylcarbamazine in Treatment of Allergic Rhinitis: A Double Blind Randomised Controlled Trial

There are many evidences showing diethylcarbamazine as a potential drug for the treatment of allergic rhinitis. This study evaluated the effectiveness of diethylcarbamazine in the treatment of allergic rhinitis and compared it with montelukast and levocetirizine. This parallel double-blind randomized clinical trial was done in allergic rhinitis patients. Seven hundred and twelve participants who met the inclusion criteria and provided informed written consent were randomized and divided into 2 equal groups. Diethylcarbamazine 300 mg/day orally in divided doses was given to group A, and montelukast 10 mg and levocetirizine 5 mg/day orally at night for 21 days was given to group B. Primary outcomes were the change in symptoms, absolute eosinophil count, serum total IgE, phadiatop and response in skin prick from baseline to 21 days and 3 months after treatment. Secondary outcome was to compare it with montelukast and levocetirizine. The mean (SD) age of the patients was 33 (10.6) years, with 374 (52.5%) males and 338 (47.5%) females. There was statistically significant improvement in all the parameters in both groups. Improvement was better with diethylcarbamazine compared to montelukast and levocetirizine and the effects were sustained for 3 months in diethylcarbamazine group. The findings suggest that diethylcarbamazine is effective in the treatment of allergic rhinitis. It gives better control and is cost-effective than montelukast and levocetirizine. Trial Registration: https://www.ctri.nic.in Identifier: CTRI/2020/03/024145 registered on 20-03-2020.

Radioprotective effects of gliclazide against irradiation-induced cardiotoxicity and lung injury through inhibiting oxidative stress

Radiotherapy is one of the main treatments for localized primary cancer in patients. Cardiotoxicity and lung injury are two of the main side effects of oxidative stress following radiotherapy in patients with thoracic region cancer. Gliclazide (GLZ) as an antihyperglycemic drug has antioxidant, anti-inflammatory, and anti-apoptotic activities. This study aimed to evaluate the effect of GLZ in cardiotoxicity and lung injury induced by irradiation (IR). In this experimental study, 64 mice were divided into eight groups: control, GLZ (5, 10, and 25 mg/kg), IR (6 Gy), and IR + GLZ (in three doses). GLZ was administrated for 8 consecutive successive days and mice were exposed with IR on the 9th day of study. On the 10th day of study, tissue biochemical assay and at 14th day of study, histopathological assay were performed to evaluate for cardiotoxicity and lung injury. The findings revealed that IR induces atypical features in heart and lung histostructure, and oxidative stress (an increase of MDA, PC levels, and decrease of GSH content) in these tissues. GLZ administration preserved heart and lung damages and improves oxidative stress markers in mice. Data have authenticated that GLZ could protect heart and lung histostructure against oxidative stress-induced injury through inhibiting oxidative stress.

Radioprotective effect of X-ray abdominal FLASH irradiation: Adaptation to oxidative damage and inflammatory response may be benefiting factors

BACKGROUND

Ultrahigh dose-rate irradiation (FLASH-IR) was reported to be efficient in tumor control while reducing normal tissue radiotoxicity. However, the mechanism of such phenomenon is still unclear. Besides, the FLASH experiments using high energy X-ray, the most common modality in clinical radiotherapy, is rarely reported. This study aims to investigate the radiobiological response using 6 MV X-ray FLASH-IR or conventional dose-rate IR (CONV-IR).

METHODS

The superconducting linac of Chengdu THz Free Electron Laser (CTFEL) facility was used for FLASH-IR, a diamond radiation detector and a CeBr₃ scintillation detector were used to monitor the time structure and dose rate of FLASH pulses. BALB/c nude mice received whole abdominal 6 MV X-ray FLASH-IR or CONV-IR, the prescribed dose was 15 Gy or 10 Gy and the delivered absolute dose was monitored with EBT3 films. The mice were either euthanized 24 h post-IR to evaluate acute tissue responses or followed up for 6 weeks to observe late-stage responses and survival probability. Complete blood count, histological analyses, and measurement of cytokine expression and redox status were performed.

RESULTS

The mean dose rate of >150 Gy/s and instantaneous dose rate of >5.5×10⁵ Gy/s was reached in FLASH-IR at the center of mice body. After 6 weeks' follow-up of mice that received 15 Gy IR, the FLASH group showed faster body weight recovery and higher survival probability than the CONV group. Histological analysis showed that FLASH-IR induced less acute intestinal damage than CONV-IR. Complete blood count and cytokine concentration measurement found that the inflammatory blood cell counts and pro-inflammatory cytokine concentrations were elevated at the acute stage after both FLASH-IR and CONV-IR. However, FLASH irradiated mice had significantly fewer inflammatory blood cells and diminished pro-inflammatory cytokine at the late stage. Moreover, higher reactive oxygen species (ROS) signal intensities but significantly reduced lipid peroxidation were found in the FLASH group than in the CONV group in the acute stage.

CONCLUSIONS

The radioprotective effect of 6 MV X-ray FLASH-IR was observed. The differences in inflammatory responses and redox status between the two groups may be the factors responsible for reduced radiotoxicities following FLASH-IR. Further studies are required to thoroughly evaluate the impact of ROS on FLASH effect. This article is protected by copyright. All rights reserved.

Repurposing Pharmaceuticals Previously Approved by Regulatory Agencies to Medically Counter Injuries Arising Either Early or Late Following Radiation Exposure

The increasing risks of radiological or nuclear attacks or associated accidents have served to renew interest in developing radiation medical countermeasures. The development of prospective countermeasures and the subsequent gain of Food and Drug Administration (FDA) approval are invariably time consuming and expensive processes, especially in terms of generating essential human data. Due to the limited resources for drug development and the need for expedited drug approval, drug developers have turned, in part, to the strategy of repurposing agents for which safety and clinical data are already available. Approval of drugs that are already in clinical use for one indication and are being repurposed for another indication is inherently faster and more cost effective than for new agents that lack regulatory approval of any sort. There are four known growth factors which have been repurposed in the recent past as radiomitigators following the FDA Animal Rule: Neupogen, Neulasta, Leukine, and Nplate. These four drugs were in clinic for several decades for other indications and were repurposed. A large number of additional agents approved by various regulatory authorities for given indications are currently under investigation for dual use for acute radiation syndrome or for delayed pathological effects of acute radiation exposure. The process of drug repurposing, however, is not without its own set of challenges and limitations.

The Radiosensitizing Effect of Olanzapine as an Antipsychotic Medication in Glioblastoma Cell

BACKGROUND

Radiotherapy is used as one of the most effective regimens for cancer treatment, while radioresistance is a major drawback in cancer treatment.

OBJECTIVES

The aim of this study was to evaluate the sensitizing effect of olanzapine (OLA) with X-ray on glioblastoma (U-87 MG) cells death.

METHODS

The synergistic killing effect of OLA with ionizing radiation (IR) on glioma was evaluated by colony formation assay. The generations of reactive oxygen species (ROS) and protein carbonyl (PC) as oxidized protein were determined in OLA and irradiated cells.

RESULTS

The results of this study showed that OLA reduced the number of colonies in irradiated glioma cells. OLA elevated ROS and PC levels in irradiated cells. The synergistic killing effect of OLA with IR in U-87 MG cell was observed at concentrations 1 µM and 20 µM of OLA. The maximum radiosensitizing effect of OLA was observed at concentration of 20 µM.

CONCLUSION

The present study demonstrates that OLA has radiosensitizing effect on cell death induced by IR in glioma cells.

Role and Mechanism of Maresin-1 in Acute Lung Injury Induced by Trauma-Hemorrhagic Shock

Background

It is reported that trauma hemorrhagic shock (THS) could resulted in organ injury and is related to a high mortality rate. Maresin-1 (MaR1), a derived medium through biosynthesis, is involved in inflammatory responses. However, the mechanism of MaR1 against acute lung injury needs to be further understood. This report aimed to explore whether MaR1 had a protective effect on lung injury.

Material/Methods

We constructed a THS-induced acute lung damage rat model and then treated the rats with MaR1. We determined Evan’s blue dye (EBD) lung permeability, lung permeability index, wet/dry (W/D) weight ratio, nitric oxide (NO) concentration and inducible nitric oxide synthase (iNOS) expression in lung tissue samples. The inflammation-related cytokines levels in the bronchoalveolar lavage fluid (BALF) and serum of rats were determined by enzyme-linked immunosorbent assay (ELISA). Finally, the TLR4/p38MAPK/NF-κB pathway was analyzed by quantitative real-time polymerase chain reaction and western blot assay.

Results

The increased EBD ratio, lung permeability index and W/D weight ratio, NO concentration and iNOS levels were suppressed by MaR1 treatment. THS-induced over-production of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in BALF and serum was suppressed by MaR1. Besides, the TLR4/p38MAPK/NF-κB pathway activation in THS-induced rats were inhibited by MaR1 treatment.

Conclusions

Our study showed that MaR1 could effectively alleviated THS-induced lung injury via inhibiting the excitation of the TLR4/p38MAPK/NF-κB pathway in THS-induced rats, suggesting that MaR1 might be a novel agent for lung damage treatment.