O2/3 exposure inhibits cell progression affecting cyclin B1/cdk1 activity in SK-N-SH while induces apoptosis in SK-N-DZ neuroblastoma cells

Low ozone concentrations do not exert cytoprotective effects on tamoxifen-treated breast cancer cells in vitro

Medical treatment with low ozone concentrations proved to exert therapeutic effects in various diseases by inducing a cytoprotective antioxidant response through the nuclear factor erythroid derived-like 2 (Nrf2) transcription factor pathway. Low ozone doses are increasingly administered to oncological patients as a complementary treatment to mitigate some adverse side-effects of antitumor treatments. However, a widespread concern exists about the possibility that the cytoprotective effect of Nrf2 activation may confer drug resistance to cancer cells or at least reduce the efficacy of antitumor agents. In this study, the effect of low ozone concentrations on tamoxifen-treated MCF7 human breast cancer cells has been investigated in vitro by histochemical and molecular techniques. Results demonstrated that cell viability, proliferation and migration were generally similar in tamoxifen-treated cells as in cells concomitantly treated with tamoxifen and ozone. Notably, low ozone concentrations were unable to overstimulate the antioxidant response through the Nfr2 pathway, thus excluding a possible ozone-driven cytoprotective effect that would lead to increased tumor cell survival during the antineoplastic treatment. These findings, though obtained in an in vitro model, support the hypothesis that low ozone concentrations do not interfere with the tamoxifen-induced effects on breast cancer cells.

Ozone mediates the anticancer effect of air plasma by triggering oxidative cell death caused by H2O2 and iron

Cold atmospheric plasmas and plasma-treated solutions (PTSs) have emerged as promising approaches in cancer treatment because of their tumor-selective actions. While oxidative stress is critical for their effects, the precise mechanisms, including chemical mediators, remain obscure. Previously, we reported that air plasma-activated medium (APAM) exhibited tumor-selective anticancer activity. The fragmentation of mitochondria and their asymmetrical assembly around the peripheral regions of the damaged nucleus, namely, monopolar perinuclear mitochondrial clustering (MPMC), proceed to the effect. Subsequently, we found that APAM had a substantial amount of O3 in addition to hydrogen peroxide (H2O2), nitrile (NO2-), and nitrate (NO3-). In the present study, we investigated the possible role of O3 in the anticancer effect. For this purpose, we created a nitrogen oxide-free ozonated medium ODM. ODM exhibited potent cytotoxicity against various cancer but not nonmalignant cells. ODM also increased MPMC, hydroxyl radicals, lipid peroxides, and their shifts to perinuclear sites in cancer cells. Catalase and iron chelation prevented these events and cytotoxicity. ODM also decreases the intracellular labile irons while increasing those within mitochondria. ODM had substantial H2O2, but this oxidant failed to cause MPMC and cytotoxicity. These results show that ODM can mimic the effects of APAM, including MPMC and tumor-selective anticancer effects. The findings suggest that O3 is critical in mediating the anticancer effects of APAM by triggering oxidative cell death caused by H2O2 and iron.

Ozone therapy for high-grade glioma: an overview

High-grade gliomas (grades III and IV) are highly malignant and aggressive brain tumors that present significant treatment challenges. Despite advances in surgery, chemotherapy, and radiation therapy, the prognosis for patients with glioma remains poor, with a median overall survival (mOS) range of 9-12 months. Therefore, exploring new and effective therapeutic strategies to improve glioma prognosis is of utmost importance and ozone therapy is a viable option. Ozone therapy has been used in various cancers, such as colon, breast, and lung, yielding significant results in preclinical studies and clinical trials. Only a few studies have been conducted on gliomas. Furthermore, since the metabolism of brain cells involves aerobic glycolysis, ozone therapy may improve the oxygen condition and enhance glioma radiation treatment. However, understanding the correct ozone dosage and optimal time of administration remains challenging. Herein, we hypothesize that ozone therapy should be more effective in gliomas compared with other tumors. This study provides an overview of the use of ozone therapy in high-grade glioma, including mechanisms of action, preclinical data, and clinical evidence.

Hypoxia signaling in cancer: Implications for therapeutic interventions

Hypoxia is a persistent physiological feature of many different solid tumors and a key driver of malignancy, and in recent years, it has been recognized as an important target for cancer therapy. Hypoxia occurs in the majority of solid tumors due to a poor vascular oxygen supply that is not sufficient to meet the needs of rapidly proliferating cancer cells. A hypoxic tumor microenvironment (TME) can reduce the effectiveness of other tumor therapies, such as radiotherapy, chemotherapy, and immunotherapy. In this review, we discuss the critical role of hypoxia in tumor development, including tumor metabolism, tumor immunity, and tumor angiogenesis. The treatment methods for hypoxic TME are summarized, including hypoxia-targeted therapy and improving oxygenation by alleviating tumor hypoxia itself. Hyperoxia therapy can be used to improve tissue oxygen partial pressure and relieve tumor hypoxia. We focus on the underlying mechanisms of hyperoxia and their impact on current cancer therapies and discuss the prospects of hyperoxia therapy in cancer treatment.

The apoptotic effect of ozone therapy on mitochondrial activity of highly metastatic breast cancer cell line MDA-MB-231 using in vitro approaches

Ozone (O₃) gas is the triatomic state of oxygen and it is used as a disinfection agent due to its strong oxidizing effect, since its discovery in the mid-nineteenth century. Ozone therapy is also an alternative therapeutic approach for some diseases like circulatory disorders, AIDS, asthma, cardiovascular diseases, and certain types of cancer by increasing the oxygen levels in the blood by external addition of ozone to the body. In this study, the therapeutic potential of ozone therapy was examined by inhibiting the growth of breast cancer cells in a dose-dependent procedure. Ozone concentrations varying from 5 to 20 ​μg/ml were applied to the MDA-MB-231, human breast adenocarcinoma and HUVEC, human umbilical vein endothelium, cell lines, and MDA cells demonstrated an increased rate of death while its migration potential decreases. RT-PCR analysis showed mRNA expression levels of pro-apoptotic genes demonstrated higher folds in MDA cells after 10 ​μg/ml treatment. In the same context, Annexin V/PI and cell cycle analysis also concluded that ozone therapy causes apoptotic cell death on breast tumor cells. The use of ozone therapy for cancer treatment requires further and extensive research. However, this research has shown that ozone therapy is a promising source for cancer treatment in a way by inhibiting the proliferation of breast tumor cells.

Systemic Review: Ozone: A Potential New Chemotherapy

In the last sixty years, publications in reputed journals have shown the preclinical positive effect of ozone gas in cancer cells. However, the translation of these results into clinical practice is far away from success. A comprehensive approach is necessary for this, and oncologists and researchers need guidance from medical specialists with in-depth knowledge of ozone in medicine. In this article, we review the evidence around this question and suggest different potential research lines to those interested in this exciting field.

Ozone induces BEL7402 cell apoptosis by increasing reactive oxygen species production and activating JNK

Background

Oxidative stress is an important factor in the modulation of both tumorigenesis and anticancer responses. Ozone (O₃) is a strong oxidant that causes redox reactions and exerts anticancer effects in various types of cancer cells. However, the pathways involved in O₃-induced cell death are not well understood.

Methods

In vitro human hepatocellular carcinoma (HCC) BEL7402 cells were treated with various O₃ concentrations to evaluate O₃ cytotoxicity by Cell Counting Kit-8 (CCK-8) assay and flow cytometry. The regulatory mechanisms were analyzed by western blot analysis. In vivo, an HCC model was established to evaluate the inhibition of HCC with O₃ treatment.

Results

In vitro cells treated with O₃ exhibited a round and small morphology with nuclear shrinkage and fragmentation. The CCK-8 assay confirmed the potent cytotoxic activity of O₃ against BEL7402 cells (IC₅₀ value of 5 µg/mL). Acridine orange/ethidium bromide (AO/EB) staining revealed apoptosis of BEL7402 cells after O₃ treatment. Flow cytometry analysis showed that S phase cell cycle arrest and apoptosis increased with O₃ exposure. In addition, O3 exposure reduced the mitochondrial membrane potential (ΔΨm) and induced reactive oxygen species (ROS) accumulation. Western blot analysis showed that O₃ exposure reduced B-cell lymphoma 2 (BCL-2) expression and increased cleaved poly ADP-ribose polymerase (PARP), cytochrome C (Cyt-C), caspase-3, caspase-9, and p-JNK expression. In vivo, treatment with intratumor injection O₃ (20 µg/mL) inhibited HCC growth.

Conclusions

Overall, our findings showed that O₃ induces BEL7402 cell apoptosis via the intrinsic mitochondria-dependent pathway. Therefore, O₃ has therapeutic potential for HCC.

Cannabidiol and Oxygen-Ozone Combination Induce Cytotoxicity in Human Pancreatic Ductal Adenocarcinoma Cell Lines

Simple Summary

Pancreatic cancer (PC) is related to lifestyle risks, chronic inflammation, and germline mutations. Surgical resection and adjuvant chemotherapy are the main therapeutic strategies but are less effective in patients with high-grade tumors. Oxygen-ozone (O₂/O₃) therapy is an emerging alternative tool for the treatment of several clinical disorders. The advantages of using cannabinoids have been evaluated in several human cancers. Regarding PC, activation of cannabinoid receptors was found to induce PC cell apoptosis without affecting the normal pancreas cells. Herein, we evaluate the anticancer effect of cannabidiol (CBD) and O₂/O₃, alone or in combination, on two human pancreatic ductal adenocarcinoma (PDAC) cell lines, PANC-1 and MiaPaCa-2, examining expression profiles of 92 pancreatic adenocarcinoma associated genes, cytotoxicity, migration properties, and cell death. Finally, we assess the combination effects with gemcitabine and paclitaxel. Summarizing, for the first time the antitumoral effect of combined therapy with CBD and oxygen-ozone therapy in PDAC is evidenced.

Abstract

Pancreatic cancer (PC) is related to lifestyle risks, chronic inflammation, and germline mutations in BRCA1/2, ATM, MLH1, TP53, or CDKN2A. Surgical resection and adjuvant chemotherapy are the main therapeutic strategies but are less effective in patients with high-grade tumors. Oxygen-ozone (O₂/O₃) therapy is an emerging alternative tool for the treatment of several clinical disorders. O₂/O₃ therapy has been found to ameliorate mechanisms promoting chronic pain and inflammation, including hypoxia, inflammatory mediators, and infection. The advantages of using cannabinoids have been evaluated in vitro and in vivo models of several human cancers. Regarding PDAC, activation of cannabinoid receptors was found to induce pancreatic cancer cell apoptosis without affecting the normal pancreas cells. In a murine model of PDAC, a combination of cannabidiol (CBD) and gemcitabine increased survival length by nearly three times. Herein, we evaluate the anticancer effect of CBD and O₂/O₃, alone or in combination, on two human PDAC cell lines, PANC-1 and MiaPaCa-2, examining expression profiles of 92 pancreatic adenocarcinoma associated genes, cytotoxicity, migration properties, and cell death. Finally, we assess the combination effects with gemcitabine and paclitaxel. Summarizing, for the first time the antitumoral effect of combined therapy with CBD and oxygen-ozone therapy in PDAC is evidenced.

Hyperoxia Alters Ultrastructure and Induces Apoptosis in Leukemia Cell Lines

Oxygenation conditions are crucial for growth and tumor progression. Recent data suggests a decrease in cancer cell proliferation occurring after exposure to normobaric hyperoxia. Those changes are associated with fractal dimension. The purpose of this research was to study the impact of hyperoxia on apoptosis and morphology of leukemia cell lines. Two hematopoietic lymphoid cancer cell lines (a T-lymphoblastoid line, JURKAT and a B lymphoid line, CCRF-SB) were tested under conditions of normobaric hyperoxia (FiO₂ > 60%, ± 18h) and compared to a standard group (FiO₂ = 21%). We tested for apoptosis using a caspase-3 assay. Cell morphology was evaluated by cytospin, microphotography after coloration, and analysis by a fractal dimension calculation software. Our results showed that exposure of cell cultures to transient normobaric hyperoxia induced apoptosis (elevated caspase-3) as well as significant and precocious modifications in cell complexity, as highlighted by increased fractal dimensions in both cell lines. These features are associated with changes in structure (pycnotic nucleus and apoptosis) recorded by microscopic analysis. Such morphological alterations could be due to several molecular mechanisms and rearrangements in the cancer cell, leading to cell cycle inhibition and apoptosis as shown by caspase-3 activity. T cells seem less resistant to hyperoxia than B cells.

Ozone Therapy as Adjuvant for Cancer Treatment: Is Further Research Warranted?

Introduction

This article provides an overview of the potential use of ozone as an adjuvant during cancer treatment.

Methods

We summarize the findings of the most relevant publications focused on this goal, and we include our related clinical experience.

Results

Over several decades, prestigious journals have published in vitro studies on the capacity of ozone to induce direct damage on tumor cells and, as well, to enhance the effects of radiotherapy and chemotherapy. Indirect effects have been demonstrated in animal models: immune modulation by ozone alone and sensitizing effect of radiotherapy by concurrent ozone administration. The effects of ozone in modifying hemoglobin dissociation curve, 2,3-diphosphoglycerate levels, locoregional blood flow, and tumor hypoxia provide additional support for potential beneficial effects during cancer treatment. Unfortunately, only a few clinical studies are available. Finally, we describe some works and our experience supporting the potential role of local ozone therapy in treating delayed healing after tumor resection, to avoid delays in commencing radiotherapy and chemotherapy.

Conclusions

In vitro and animal studies, as well as isolated clinical reports, suggest the potential role of ozone as an adjuvant during radiotherapy and/or chemotherapy. However, further research, such as randomized clinical trials, is required to demonstrate its potential usefulness as an adjuvant therapeutic tool.

Intra-tumoral treatment with oxygen-ozone in glioblastoma: A systematic literature search and results of a case series

Despite progress in surgery and radiochemotherapy, the prognosis of glioblastoma (GB) remains poor. GB cells exhibit a preference for hypoxia to maintain their tumor-forming capacity. Treatment strategies utilizing oxygen (O₂) or ozone (O3) and generating reactive oxygen species induce cell growth inhibition and apoptosis. The anti-tumorigenic properties of O2-O3 are accompanied by a key role in regulating immunogenicity. The present study reported a case series of an intra-tumoral O2-O3 application in recurrent GB. Following surgery in combination with standard radiochemotherapy, O2-O3 (5 ml at 40 µg/ml) was applied every four weeks into the tumor vicinity. The patients received a median of 27 (range, 3–44) O2-O3 applications. In addition, a systematic literature search was performed in order to evaluate the role of O3 in the treatment of malignancies. The median overall survival rate was 40 (range, 16–53) months. The median survival rate following the first recurrence or the initiation of the O2-O3 treatment, respectively, was 34 (range, 12–53) months. In one patient, a local infection and in another, hemorrhage occurred, necessitating in both the temporary removal of the reservoir. The data from the present study support the potential benefit of an intra-tumoral O2-O3 application in recurrent GB. The scientific literature revealed by the bibliographic search suggests that O3 may be considered a viable adjuvant therapy in oncological patients. The present study may serve as a starting point for further observational and clinical studies elucidating the cellular and systemic effects of O2 and/or O3 and demonstrating their efficacy and safety in larger patient samples.

Effect of hyperoxia on the viability and proliferation of the primary type II alveolar epithelial cells

To observe the effect of hyperoxia on the growth of type II alveolar epithelial cells (AEC II). The lungs of 19-day gestation fetal rats were primary cultured and the AEC II were purified by differential adhesion method. The cells were divided into control (normoxia) group and hyperoxia group. The cell growth, cell viability, cell apoptosis, and cell cycle were examined at 2, 4, 6, and 8 days of normoxia or hyperoxia exposure. The number of cells in hyperoxia-exposed group significantly decreased as compared to those of air control group. Number of cells in hyperoxia group was the highest at day 2 of exposure and gradually decreased with time. The viability of cells exposed to hyperoxia was substantially reduced compared with cells exposed to air. Percentage of cells in G1 phase and S phase in hyperoxia group increased gradually with increase in exposure duration and significant differences were seen at day 4 and day 6 compared with either the preceding time points and also with corresponding air-exposed cells. The percentage of both early apoptotic cells (Annexin-V(+)/PI(-)) and late apoptotic cells and necrotic cells (Annexin-V(+)/PI(+)) increased significantly in cells exposed to hyperoxia compared with cells exposed to air. Hyperoxia inhibits proliferation, viability and growth of AEC II and promotes apoptosis.

Effect of ozone on intestinal recovery following intestinal ischemia-reperfusion injury in a rat

BACKGROUND

Growing evidence suggests that ozone (O3) protects the host against pathological conditions mediated by reactive oxygen species by increasing the activity of antioxidant enzymes. The purpose of the present study was to examine the effect of O3 on intestinal recovery and enterocyte turnover after intestinal ischemia-reperfusion (IR) injury in rats.

METHODS

Male Sprague-Dawley rats were divided into four experimental groups: (1) sham rats underwent laparotomy; (2) sham-O3 rats underwent laparotomy and were treated with an ozone/oxygen mixture intraperitoneally and intraluminally (50 %/50 %); (3) IR rats underwent occlusion of both superior mesenteric artery and portal vein for 20 min followed by 48 h of reperfusion, and (4) IR-O3 rats underwent IR and were treated with an ozone/oxygen mixture similar to group 2. Intestinal structural changes, Park's injury score, enterocyte proliferation and enterocyte apoptosis were determined 48 h following IR. Western blot was used to determine ERK and Bax protein levels. A non-parametric Kruskal-Wallis ANOVA test was used for statistical analysis with p < 0.05 considered statistically significant.

RESULTS

Treatment of IR rats with O3 resulted in a significant increase in mucosal weight in jejunum (70 %) and ileum (32 %), mucosal DNA (twofold increase) and protein (35 %) in ileum, villus height and crypt depth in jejunum (61 and 16 %, correspondingly) and ileum (31 and 43 %, correspondingly) compared to IR animals. IR-O3 rats also had a significantly lower intestinal injury score as well as a lower apoptotic index in jejunum and ileum compared and IR animals. A significant increase in cell proliferation rates in IR-O3 animals was accompanied by increased levels of p-ERK protein.

CONCLUSIONS

Treatment with ozone prevents intestinal mucosal damage, stimulates cell proliferation and inhibits programmed cell death following intestinal IR in a rat.

Oxidative phosphorylation in cancer cells

Evidence suggests that mitochondrial metabolism may play a key role in controlling cancer cells life and proliferation. Recent evidence also indicates how the altered contribution of these organelles to metabolism and the resistance of cancer mitochondria against apoptosis-associated permeabilization are closely related. The hallmarks of cancer growth, increased glycolysis and lactate production in tumours, have raised attention due to recent observations suggesting a wide spectrum of oxidative phosphorylation deficit and decreased availability of ATP associated with malignancies and tumour cell expansion. More specifically, alteration in signal transduction pathways directly affects mitochondrial proteins playing critical roles in controlling the membrane potential as UCP2 and components of both MPTP and oxphos complexes, or in controlling cells life and death as the Bcl-2 proteins family. Moreover, since mitochondrial bioenergetics and dynamics, are also involved in processes of cells life and death, proper regulation of these mitochondrial functions is crucial for tumours to grow. Therefore a better understanding of the key pathophysiological differences between mitochondria in cancer cells and in their non-cancer surrounding tissue is crucial to the finding of tools interfering with these peculiar tumour mitochondrial functions and will disclose novel approaches for the prevention and treatment of malignant diseases. Here, we review the peculiarity of tumour mitochondrial bioenergetics and the mode it is linked to the cell metabolism, providing a short overview of the evidence accumulated so far, but highlighting the more recent advances.