Soy Isoflavones Protect Normal Tissues While Enhancing Radiation Responses

Genistein Implications in Radiotherapy: Kill Two Birds with One Stone

More than 70% of cancer patients receive radiotherapy during their treatment, with consequent various side effects on normal cells due to high ionizing radiation doses despite tumor shrinkage. To date, many radioprotectors and radiosensitizers have been investigated in preclinical studies, but their use has been hampered by the high toxicity to normal cells or poor tumor radiosensitization effects. Genistein is a naturally occurring isoflavone found in soy products. It selectively sensitizes tumor cells to radiation while protecting normal cells from radiation-induced damage, thus improving the efficacy of radiotherapy and consequent therapeutic outcomes while reducing adverse effects. Genistein protects normal cells by its potent antioxidant effect that reduces oxidative stress and mitigates radiation-induced apoptosis and inflammation. Conversely, genistein increases the radiosensitivity of tumor cells through specific mechanisms such as the inhibition of DNA repair, the arrest of the cell cycle in the G2/M phase, the generation of reactive oxygen species (ROS), and the modulation of apoptosis. These effects increase the cytotoxicity of radiation. Preclinical studies demonstrated genistein efficacy in various cancer models, such as breast, prostate, and lung cancer. Despite limited clinical studies, the existing evidence supports the potential of genistein in improving the therapeutic effect of radiotherapy. Future research should focus on dosage optimization and administration, the exploration of combination therapies, and long-term clinical trials to establish genistein benefits in clinical settings. Hence, the unique ability of genistein to improve the radiosensitivity of tumor cells while protecting normal cells could be a promising strategy to improve the efficacy and safety of radiotherapy.

Exploring Black Soybean Extract Cream for Inflammatory Dermatitis-Toward Radiation Dermatitis Relief

We aimed to evaluate the effect of black soybean extract cream (BSEC) on 2,4-dinitrochlorobenzene (DNCB)-induced dermatitis in murine models mimicking inflammatory dermatitis observed in humans. In this DNCB-induced model, BALB/c mice were spread with 100 μL of 2% DNCB twice a week for two weeks to induce skin inflammation on the shaved back skin; then, a placebo or BSEC that consisted of the volatile fraction derived from the seeds of Glycine max (L.) Merr. was applied to the DNCB-sensitized mice for 7 days. Gross visual analysis was conducted to assess the impact of BSEC on dermatitis, and an enzyme-linked immunosorbent assay (ELISA) was subsequently performed to detect inflammatory cytokines in the presence or absence of BSEC after DNCB sensitization. Lastly, the possible mechanisms responsible for the effects of BSEC on inflammatory dermatitis were investigated in a human leukemia monocytic cell line, THP-1. Our study showed that BSEC displayed antioxidant and anti-inflammatory effects. BSEC has the ability to diminish dermatitis, and all three experiments demonstrated that BSEC effectively reduced the progression of dermatitis while significantly suppressing inflammatory responses in the preclinical models. Consequently, BSEC exhibited promising phytotherapy for inflammatory dermatitis, potentially attributed to its anti-inflammatory and antioxidant properties.

Prophylactic Use of Mepitel® Film to Prevent Radiation-Induced Moist Desquamation in Cancer Patients

Cancer patients had limited treatment options for decades, such as surgery, chemotherapy, and radiation therapy, alone or combined. However, there have been substantial improvements in recent years with the introduction of stem cell therapy, hormone therapy, anti-angiogenic treatments, immunotherapy, dendritic cell-based targeted therapy, ablation therapy, nanoparticles, natural antioxidants, radionics, chemodynamic therapy, sonodynamic therapy, and ferroptosis-based therapy. Radiation therapy, or radiotherapy, is a cancer treatment that employs high doses of radiation to eliminate cancer cells and shrink tumors. This treatment is effective as a primary, adjuvant, or palliative therapy. It is an essential, efficient, cost-effective intervention crucial for providing proper palliative oncology care. Although cancer treatment modalities such as intensity-modulated radiotherapy have advanced, they still risk harming the skin and surrounding healthy tissue. Radiotherapy may induce clinical toxicity leading to chronic or acute radiation dermatitis, depending on the toxicity caused by the therapy. Radiation dermatitis, whether in its chronic or acute form, can cause skin shedding that may result in the formation of wounds. Such shedding can also lead to non-healing ulcers and radionecrosis. Mepitel® film helps control radiation-induced moist desquamation in cancer patients. Clinical trials on the prophylactic use of Mepitel film on radiation-induced moist desquamation did not show similarities among patients from various countries; however, the film-based method is more beneficial than other methods. This review examines the various types of dressings utilized in managing radiation-induced dermatitis to enhance wound healing effectiveness while avoiding harm to newly developing tissues. Additionally, this review compares the effectiveness of using Mepitel film for treating radiation-induced moist desquamation to other methods.

Soy isoflavones alleviate lipopolysaccharide-induced depressive-like behavior by suppressing neuroinflammation, mediating tryptophan metabolism and promoting synaptic plasticity

Depression is highly prevalent in patients suffering from chronic inflammatory diseases. Dysregulated neuroinflammation and concomitant-activated microglia play a pivotal role in the pathogenesis of depression. As one of the biologically functional phytochemicals in soybeans, soy isoflavones (SI) have been reported to exhibit anti-inflammatory, antioxidant, estrogen-like and neuroprotective activities. However, there is no research on how SI administration affects the depressive-like behavior induced by neuroinflammation. Therefore, this study was conducted to evaluate the antidepressant-like action of SI in acute lipopolysaccharide (LPS)-treated mice and to explore its underlying mechanisms. An open field test, a sucrose preference experiment, a tail suspension test and a forced swimming task were conducted to assess the influence of SI on the depressive-like behavior induced by LPS injection. Then, the levels of the pro-inflammation cytokines, tryptophan (Trp) metabolism in the cortex and hippocampus, and the synaptic plasticity-related signal pathway in the hippocampus, which are involved in the pathophysiology of depression, were examined. The results showed that SI administration remarkably alleviated LPS-induced depressive-like behavior as indicated by the increased sucrose preference index and the decreased immobility time both in the tail suspension test and the forced swimming task. SI significantly suppressed neuroinflammation in the hippocampus of LPS mice, as indicated by a decrease in the levels of interleukin (IL)-1β, IL-10, tumor necrosis factor (TNF-α) and suppression of the signal pathway of TLR4/NF-κB. Additionally, SI administration regulated tryptophan (Trp) metabolism by increasing 5-hydroxytryptamine (5-HT) levels, inhibiting the release of kynurenine (KYN) in the cortex and hippocampus, and elevating the expressions of synaptic plasticity-related protein markers such as postsynaptic density-95 (PSD-95) and synaptophysin (SYN). The current study demonstrated that soy isoflavones could reverse LPS-induced depressive-like behavior by suppressing neuroinflammation, normalizing the Trp metabolism, up-regulating the expressions of synaptic plasticity-related proteins, and inhibiting the TLR4/NF-κB pathway activation in the hippocampus of mice, exerting their antidepressant-like action.

The role of isoflavones in augmenting the effects of radiotherapy

Cancer is one of the major health problems and the second cause of death worldwide behind heart disease. The traditional soy diet containing isoflavones, consumed by the Asian population in China and Japan has been identified as a protective factor from hormone-related cancers. Over the years the research focus has shifted from emphasizing the preventive effect of isoflavones from cancer initiation and promotion to their efficacy against established tumors along with chemo- and radiopotentiating effects. Studies performed in mouse models and results of clinical trials emphasize that genistein or a mixture of isoflavones, containing in traditional soy diet, could be utilized to both potentiate the response of cancer cells to radiotherapy and reduce radiation-induced toxicity in normal tissues. Currently ongoing clinical research explores a potential of another significant isoflavone, idronoxil, also known as phenoxodiol, as radiation enhancing agent. In the light of the recent clinical findings, this article reviews the accumulated evidence which support the clinically desirable interactions of soy isoflavones with radiation therapy resulting in improved tumor treatment. This review discusses important aspects of the development of isoflavones as anticancer agents, and mechanisms potentially relevant to their activity in combination with radiation therapy of cancer. It gives a critical overview of studies characterizing isoflavone targets such as topoisomerases, ENOX2/PMET, tyrosine kinases and ER receptor signaling, and cellular effects on the cell cycle, DNA damage, cell death, and immune responses.

Could Polyphenols Really Be a Good Radioprotective Strategy?

Currently, radiotherapy is one of the most effective strategies to treat cancer. However, deleterious toxicity against normal cells indicate for the need to selectively protect them. Reactive oxygen and nitrogen species reinforce ionizing radiation cytotoxicity, and compounds able to scavenge these species or enhance antioxidant enzymes (e.g., superoxide dismutase, catalase, and glutathione peroxidase) should be properly investigated. Antioxidant plant-derived compounds, such as phenols and polyphenols, could represent a valuable alternative to synthetic compounds to be used as radio-protective agents. In fact, their dose-dependent antioxidant/pro-oxidant efficacy could provide a high degree of protection to normal tissues, with little or no protection to tumor cells. The present review provides an update of the current scientific knowledge of polyphenols in pure forms or in plant extracts with good evidence concerning their possible radiomodulating action. Indeed, with few exceptions, to date, the fragmentary data available mostly derive from in vitro studies, which do not find comfort in preclinical and/or clinical studies. On the contrary, when preclinical studies are reported, especially regarding the bioactivity of a plant extract, its chemical composition is not taken into account, avoiding any standardization and compromising data reproducibility.

Exploiting DNA repair pathways for tumor sensitization, mitigation of resistance, and normal tissue protection in radiotherapy

More than half of cancer patients are treated with radiotherapy, which kills tumor cells by directly and indirectly inducing DNA damage, including cytotoxic DNA double-strand breaks (DSBs). Tumor cells respond to these threats by activating a complex signaling network termed the DNA damage response (DDR). The DDR arrests the cell cycle, upregulates DNA repair, and triggers apoptosis when damage is excessive. The DDR signaling and DNA repair pathways are fertile terrain for therapeutic intervention. This review highlights strategies to improve therapeutic gain by targeting DDR and DNA repair pathways to radiosensitize tumor cells, overcome intrinsic and acquired tumor radioresistance, and protect normal tissue. Many biological and environmental factors determine tumor and normal cell responses to ionizing radiation and genotoxic chemotherapeutics. These include cell type and cell cycle phase distribution; tissue/tumor microenvironment and oxygen levels; DNA damage load and quality; DNA repair capacity; and susceptibility to apoptosis or other active or passive cell death pathways. We provide an overview of radiobiological parameters associated with X-ray, proton, and carbon ion radiotherapy; DNA repair and DNA damage signaling pathways; and other factors that regulate tumor and normal cell responses to radiation. We then focus on recent studies exploiting DSB repair pathways to enhance radiotherapy therapeutic gain.

Identification of isoflavones in the extract of supplements for menopause symptoms by direct infusion electrospray ionization tandem mass spectrometry

In recent years high consumption of dietary supplements has been observed. However, the consumption of dietary supplements may lead to the unexpected side effects that can be related to the number of adulterated supplements quite often marketed. It has prompted the search for a fast and reliable method of identification of main active compounds in the supplements. In this study, the isoflavones present in the methanol extracts of dietary supplements for menopause symptoms were identified by using direct infusion electrospray ionization tandem mass spectrometry. The product ion spectra of [M-H]- ions derived from the extracts matched very well those obtained for standard compounds. Daidzein, genistein, and glycitein were identified in the soy-based supplements, while daidzein, formononetin, and biochanin A were identified in the red clover-based ones. The respective [M+Na]+ ions were also detected; however, their product ion spectra did not allow isoflavone identification. It can be concluded that the main isoflavones present in the extracts of dietary supplements can be successfully and quickly identified by using the direct infusion electrospray ionization in negative ion mode, followed by the tandem mass spectrometry experiment.

Manipulations of Redox Metabolism for Enhancing Radiation Therapy Responses: A Historical Perspective and Novel Hypothesis

Since the recognition during the 20th century that cancer cells demonstrated fundamental alterations in the regulation of oxidative and glycolytic metabolism, many basic as well as translational scientists have proposed that targeting metabolic differences in cancer versus normal cells could be exploited to improve cancer therapy outcomes. With the recognition that dysregulation of mitochondrial redox metabolism leads to the increased steady-state levels of superoxide and hydrogen peroxide which could contribute to both aging and cancer; radiation biologists have pursued many avenues of targeting oxidative metabolic pathways to both selectively radiosensitive cancer cells as well as protect normal tissues during cancer therapy. Recent advances in exploiting redox metabolism for improving radiochemotherapy both from a basic and translational science point of view are the focus of the papers in this current issue of Seminars in Radiation Oncology . The historical perspective underlying these areas of research as well as a unifying hypothesis for further advancing this research into clinical trials will be presented in this overview.