Celecoxib A Selective COX-2 Inhibitor Mitigates Fibrosis but not Pneumonitis Following Lung Irradiation: A Histopathological Study

Comparative study of the anti-inflammatory activity of etoricoxib and Matcha green tea against acute kidney injury induced by gamma radiation in rats

PURPOSE

The primary objective of this study was to conduct a comparative analysis of the anti-inflammatory activity between Etoricoxib (ETO) and Matcha green tea (MG) in the context of acute kidney injury (AKI) induced by ionizing gamma radiation (IR) in female rats. Furthermore, the potential impact of whole body IR exposure on the intestinal system and serum estradiol levels was investigated. Additionally, it was acknowledged that the ETO and MG treatments might have exerted favorable effects on the intestinal and hormonal responses.

MATERIALS AND METHODS

Six groups of rats were assigned to different treatments: control, ETO, MG, irradiation (IRR), ETO + IRR, and MG + IRR. The evaluation included measuring the total phenolic and flavonoid contents of ETO and MG, as well as assessing their antioxidant activity, radical scavenging capacity, reducing power, and total antioxidant capacity. Kidney function was assessed through serum creatinine and urea levels. Oxidative stress markers, including superoxide dismutase, glutathione, malondialdehyde, and catalase, were measured to evaluate the antioxidant effects of ETO and MG. The anti-inflammatory potential of the treatments was evaluated by measuring STAT-3 and interleukins (IL-6, IL-23, and IL-17) using an ELISA assay. Prostaglandin E2 receptor (PGE-2) mRNA expression, histopathological examination, and immunohistochemistry for NF-κB inhibitors were performed to investigate the underlying mechanisms in kidney tissue homogenates. Histopathological changes and DNA fragmentation in the intestinal tissues were determined, and the characterization of Matcha green tea was performed using liquid chromatography-mass spectrometry (LC-MS). This allowed for the identification and quantification of various compounds present in Matcha green tea. Furthermore, the study assessed the effect of IR and treatments on estrogen levels in female rats.

RESULTS

Data showed that both ETO and MG had the potential to mitigate the adverse effects of AKI induced by IR. Notably, MG exhibited greater efficacy in attenuating oxidative stress and inflammation associated with renal injury. These findings revealed and compared the effects of ETO and MG in alleviating AKI caused by IR. MG demonstrated greater anti-inflammatory and antioxidant properties, highlighting its potential as a natural therapeutic agent.

CONCLUSIONS

These results contribute to the growing evidence supporting the use of MG in managing IR-induced renal complications. Future studies should focus on elucidating the molecular mechanisms and optimizing the application of MG in clinical settings.

Mitigation effect of hesperidin on X-ray radiation-induced intestinal barrier dysfunction in Caco-2 cell monolayers

The tight junctions (TJs) and barrier function of the intestinal epithelium are highly sensitive to radiation. However, polyphenols can be used to reverse the effects of radiation. Here, we investigated the effects of hesperidin (hesperetin-7-rhamnoglucoside) on X-ray-induced intestinal barrier dysfunction in human epithelial Caco-2 monolayers. To examine whether hesperidin mitigated the effects of X-ray exposure (2 Gy), cell survival was evaluated and intestinal barrier function was assessed by measuring the transepithelial flux, apparent permeability coefficient (Papp), and barrier integrity. Hesperidin improved the survival of Caco-2 cell monolayers and attenuated X-ray exposure-induced intestinal barrier dysfunction. For fluorescein transport experiments, transepithelial flux and Papp of fluorescein in control group were significantly elevated by X-ray, but were restored to near control by 10 μM hesperidin pretreatment. Further, X-ray exposure decreased the barrier integrity and TJ interruption by reducing TJ-related proteins occludin and claudin-4, whereas cell monolayers pretreated with hesperidin before X-ray exposure were reinstated to control level. It was concluded that hesperidin treatment before X-ray exposure alleviated X-ray-induced intestinal barrier dysfunction through regulation of TJ-related proteins. These results indicate that hesperidin prevents and mitigates X-ray-induced intestinal barrier dysfunction.

Radioprotective Effect of Selenium Nanoparticles: A Mini Review

Materials and Methods

This study followed the PRISMA reporting guidelines to present the results. A comprehensive search was performed on electronic databases such as PubMed, Scopus, Web of Sciences, and Science Direct. Initially, 413 articles were retrieved. After removing duplicates and applying specific inclusion and exclusion criteria, 10 articles were finally included in this systematic review.

Results

The reviewed studies showed that selenium nanoparticles had anti-inflammatory and antioxidant properties. They effectively protected the kidneys, liver, and testicles from damage. Furthermore, there was evidence of efficient radioprotection for the organs examined without significant side effects.

Conclusions

This systematic review emphasizes the potential advantages of using selenium nanoparticles to prevent the negative effects of ionizing radiation. Importantly, these protective effects were achieved without causing noticeable side effects. These findings suggest the potential role of selenium nanoparticles as radioprotective agents, offering possible therapeutic applications to reduce the risks related to ionizing radiation exposure in medical imaging and radiotherapy procedures.

Radiation-induced Testicular Damage in Mice: Protective Effects of Apigenin Revealed by Histopathological Evaluation

BACKGROUND

Radiation exposure poses a significant threat to reproductive health, particularly the male reproductive system. The testes, being highly sensitive to radiation, are susceptible to damage that can impair fertility and overall reproductive function. The study aims to investigate the radioprotective effects of apigenin on the testis through histopathological evaluation.

MATERIALS AND METHODS

This research involved utilizing a total of 40 mice, which were randomly divided into eight groups of five mice each. The groups were categorized as follows: A) negative control group, B, C, and D) administration of apigenin at three different doses (0.3 mg/kg, 0.6 mg/kg, and 1.2 mg/kg) respectively, E) irradiation group, and F, H, and I) administration of apigenin at three different doses (0.3 mg/kg, 0.6 mg/kg, and 1.2 mg/kg) in combination with irradiation. The irradiation procedure involved exposing the mice to a 2Gy X-ray throughout their entire bodies. Subsequently, histopathological assessments were conducted seven days after the irradiation process.

RESULTS

The findings indicated that radiation exposure significantly impacted the spermatogenesis system. This research provides evidence that administering apigenin to mice before ionizing radiation effectively mitigated the harmful effects on the testes. Apigenin demonstrated radioprotective properties, positively influencing various parameters, including the spermatogenesis process and the presence of inflammatory cells within the tubular spaces.

CONCLUSION

Apigenin can provide effective protection for spermatogenesis, minimize the adverse effects of ionizing radiation, and safeguard normal tissues.

Radioprotective effect of Malva sylvestris L. against radiation-induced liver, kidney and intestine damages in rat: A histopathological study

Background

Ionizing radiation (IR) is widely used in the treatment of cancer in radiotherapy. One of the main concerns of patients with gastrointestinal cancers undergoing radiotherapy is the harmful side effects of IR on normal tissues. The liver, kidney, and duodenum are usually exposed to high doses of radiation in the treatment of some cancers in abdominal region radiotherapy. We aimed to assess the radioprotective effects of Malva sylvestris L. against IR damages to the abdominal region.

Materials and methods

This current study was conducted on 45 rats divided randomly into nine groups of five: A) negative control group, B) sham group, C) irradiation group, D) mallow treatment-1(200gr/kg), E) mallow treatment-2(400gr/kg), F) mallow treatment-3(600gr/kg), G) mallow treatment-4(200gr/kg) plus irradiation, H) mallow treatment-5(400gr/kg) plus irradiation, I) mallow treatment-6(600gr/kg) plus irradiation. Irradiation was performed with a 6Gy x-ray. Histopathological evaluations were performed 10 days after irradiation.

Results

The histopathological examination results confirmed that preventive therapy with the effective dose of mallow reduced the liver, kidney, and intestine damage induced by radiation. The dose of 400 mg/kg was more effective than other selected dose in improving the damage caused by irradiation in the studied tissues.

Conclusion

This study concludes that Malva sylvestris L. contributed to significant improvements in radiation-induced histological parameters of the liver and kidney and, to a lesser extent, in the intestine. These results collectively indicate that mallow is an effective radioprotective agent.

Lung Pneumonitis and Fibrosis in Cancer Therapy: A Review on Cellular and Molecular Mechanisms

Fibrosis and pneumonitis are the most important side effects of lung tissue following cancer therapy. Radiotherapy and chemotherapy by some drugs, such as bleomycin, can induce pneumonitis and fibrosis. Targeted therapy and immunotherapy also may induce pneumonitis and fibrosis to a lesser extent compared to chemotherapy and radiotherapy. Activation of lymphocytes by immunotherapy or infiltration of inflammatory cells such as macrophages, lymphocytes, neutrophils, and mast cells following chemo/radiation therapy can induce pneumonitis. Furthermore, the polarization of macrophages toward M2 cells and the release of anti-inflammatory cytokines stimulate fibrosis. Lung fibrosis and pneumonitis may also be potentiated by some other changes such as epithelial-mesenchymal transition (EMT), oxidative stress, reduction/oxidation (redox) responses, renin-angiotensin system, and the upregulation of some inflammatory mediators such as a nuclear factor of kappa B (NF-κB), inflammasome, cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS). Damages to the lung vascular system and the induction of hypoxia also can induce pulmonary injury following chemo/radiation therapy. This review explains various mechanisms of the induction of pneumonitis and lung fibrosis following cancer therapy. Furthermore, the targets and promising agents to mitigate lung fibrosis and pneumonitis will be discussed.

Exploring Nitric Oxide (NO)-Releasing Celecoxib Derivatives as Modulators of Radioresponse in Pheochromocytoma Cells

COX-2 can be considered as a clinically relevant molecular target for adjuvant, in particular radiosensitizing treatments. In this regard, using selective COX-2 inhibitors, e.g., in combination with radiotherapy or endoradiotherapy, represents an interesting treatment option. Based on our own findings that nitric oxide (NO)-releasing and celecoxib-derived COX-2 inhibitors (COXIBs) showed promising radiosensitizing effects in vitro, we herein present the development of a series of eight novel NO-COXIBs differing in the peripheral substitution pattern and their chemical and in vitro characterization. COX-1 and COX-2 inhibition potency was found to be comparable to the lead NO-COXIBs, and NO-releasing properties were demonstrated to be mainly influenced by the substituent in 4-position of the pyrazole (Cl vs. H). Introduction of the N-propionamide at the sulfamoyl residue as a potential prodrug strategy lowered lipophilicity markedly and abolished COX inhibition while NO-releasing properties were not markedly influenced. NO-COXIBs were tested in vitro for a combination with single-dose external X-ray irradiation as well as [¹⁷⁷Lu]LuCl₃ treatment in HIF2α-positive mouse pheochromocytoma (MPC-HIF2a) tumor spheroids. When applied directly before X-ray irradiation or ¹⁷⁷Lu treatment, NO-COXIBs showed radioprotective effects, as did celecoxib, which was used as a control. Radiosensitizing effects were observed when applied shortly after X-ray irradiation. Overall, the NO-COXIBs were found to be more radioprotective compared with celecoxib, which does not warrant further preclinical studies with the NO-COXIBs for the treatment of pheochromocytoma. However, evaluation as radioprotective agents for healthy tissues could be considered for the NO-COXIBs developed here, especially when used directly before irradiation.

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.

Radioprotective Mechanisms of Arbutin: A Systematic Review

PURPOSE

Efforts to produce radioprotective agents of high potential are appropriate strategies for overcoming possible IR toxicity in organisms. The present research aims to evaluate the signaling pathways and mechanisms through which arbutin exerts radioprotective effects on organisms.

METHODS

The databases of PubMed, Web of Sciences, Google Scholar, and Scopus were searched to find studies that reported radioprotective effects for arbutin. Besides, the data were searched within the time period from 2010 to 2020.

RESULTS

Five research articles met our criteria, which were included in the analysis based on their relevance to the topic. The present systematic review provides conclusions about various mechanisms and pathways through which arbutin induces radioprotection.

CONCLUSIONS

Based on the relevant studies, various mechanisms can be proposed for inducing radioprotective effects by arbutin, including inhibition of oxidative stress, apoptosis, and inflammation.

Scorpion bradykinin potentiating factor mitigates lung damage induced by γ-irradiation in rats: Insights on AngII/ACE/Ang(1-7) axis

The goal of this research is to study the mitigating impact of bradykinin potentiating factor (BPF) found in scorpion Androctonus bicolor venom on irradiation-induced lung damage as a new functional target for angiotensin-converting enzyme inhibitors (ACEIs). Male rats were exposed to 7 Gy of γ-radiation as a single dose, with a biweekly intraperitoneal injection of 1 μg/g BPF. Gamma irradiation not only boosted the ACE activity and angiotensin II (Ang II) level, in lung tissue but also significantly depressed the angiotensin (1-7) (Ang (1-7)) that, lead to lung toxicity through a significant elevation of pulmonary levels of CXC-chemokine receptor 4 (CXCR4), toll-like receptor 4 (TLR4), nitric oxide (NO) and lactate dehydrogenase (LDH) activity with a marked disruption in oxidative stress markers, via a reduction in the level of total thiol (tSH) and superoxide dismutase (SOD) activity associated with an elevation in protein carbonyl (PCO) contents. In addition, apoptotic consequences of gamma irradiation were evidenced by raising the levels of mitogen-activated protein kinase (MAPK), C-Jun N-Terminal Kinases (JNK), and cleaved caspase-3. BPF administration leads to ACE inhibition, consequently sustaining decreased Ang II alongside increased Ang (1-7) production. Those sensitive molecules reduce irradiated lung issues. In conclusion, BPF significantly diminished the biochemical and histopathological consequences of radiation through renin-angiotensin system (RAS) control and ACE suppression in the lung.