Free radicals: Relationship to Human Diseases and Potential Therapeutic applications

Ozone: complicated effects in central nervous system diseases

Oxidative stress is closely related to various diseases. Ozone can produce redox reactions through its unique response. As a source of the oxidative stress response, the strong oxidizing nature of ozone can cause severe damage to the body. On the other hand, low ozone concentrations can activate various mechanisms to combat oxidative stress and achieve therapeutic effects. Some animal experiments and clinical studies have revealed the potential medical value of ozone, indicating that ozone is not just a toxic gas. By reviewing the mechanism of ozone and its therapeutic value in treating central nervous system diseases (especially ischemic stroke and Alzheimer's disease) and the toxic effects of ozone, we find that ozone inhalation and a lack of antioxidants or excessive exposure lead to harmful impacts. However, with adequate antioxidants, ozone can transmit oxidative stress signals, reduce inflammation, reduce amyloid β peptide levels, and improve tissue oxygenation. Similar mechanisms to those of possible new drugs for treating ischemic stroke and Alzheimer's disease indicate the potential of ozone. Nevertheless, limited research has restricted the application of ozone. More studies are needed to reveal the exact dose-effect relationship and healing effect of ozone.

N-Carbazolyl π-Radical and Its Antiaromatic Nitrenium Ion: A Threshold Photoelectron Spectroscopic Study

Understanding the structure and properties of heterocyclic radicals and their cations is crucial for elucidating reaction mechanisms as they serve as versatile synthetic intermediates. In this work, the N-carbazolyl radical 1 was generated via pyrolysis and characterized using photoion mass-selected threshold photoelectron spectroscopy coupled with tunable vacuum-ultraviolet synchrotron radiation. The N-centered radical 1 is classified as a π-radical (2B1), with the unpaired electron found to be delocalized over the central five-membered ring of the carbazole. Adiabatic ionization energies corresponding to the transition from radical 1 to its singlet 1+(1A1) and triplet 1+(3B2) cations were determined to be 7.70 ± 0.03 and 8.14 ± 0.03 eV, respectively. The antiaromatic nitrenium ion 1+ exhibits a singlet ground state with an experimental singlet-triplet energy gap (ΔES-T) of -0.44 eV (10.1 kcal/mol), in very good agreement with theory. N-centered radicals are found to have a higher ionization energy than their C-centered analogues due to stabilization of the singly occupied molecular orbital.

Intracellular Generation of Alkyl Radicals Enabled by a Self-Catalytic ATRP Nanoinitiator

Oxygen-independent alkyl radicals (R•) have demonstrated great promise in combating tumor hypoxia. Currently, Azo compounds have been the primary source of R•, suffering from external stimuli and decomposition during circulation. Herein, we developed a self-catalytic ATRP nanoinitiator that could generate R• via glutathione (GSH) reduction and thus selectively induce apoptosis of tumor cells. Specifically, a conjugation of laccase (possessing a copper(II) complex) and polymeric alkyl bromide, poly(iBBr), was fabricated to yield an ATRP nanoinitiator (Lac-P(iBBr)). After internalization by cells featured with overexpressed GSH, copper(II) in Lac-P(iBBr) was reduced to copper(I) by GSH, which abstracted the Br atom in poly(iBBr) to yield toxic R•. Moreover, GSH-depletion intensified the oxidative damage caused by R•. Efficient generation of R• by Lac-P(iBBr) could happen in lab flasks, living cells, and tumor-bearing mice without any external stimuli, as demonstrated by the radical product, as well as the consumption of GSH. Moreover, the self-catalytic ATRP nanoinitiator significantly induced cell apoptosis and suppressed tumor growth. Our study expands the chemical toolbox to manipulate cell fates.

Limitations and Challenges of Antioxidant Therapy

Our bodies are constantly exposed to or producing free radicals nearly on a daily basis. These highly reactive molecules are generated through a variety of internal and external processes and pathways within the body. If these free radicals are not neutralized by antioxidants, they can lead to a state of oxidative stress, which has been linked to a wide range of severe and debilitating disorders affecting various systems in the human body. This involves neurodegenerative diseases, diabetes, atherosclerosis, fatty liver, inflammation, and aging. Thankfully, the human body is armed with a repertoire of powerful antioxidants with different natures and modes of action. The recent decades witnessed the publication of enormous papers proving antioxidant activity of a novel synthesized compound, plant extract, or a purified drug in vitro, in vivo, and even on human beings. However, the efficacy of antioxidant therapies in clinical trials, including selenium, vitamin C, vitamin E, and vitamin A, has been notably inconsistent. This inconsistency can be primarily ascribed to different factors related to the nature of free radical generation, purpose and the specific type of therapy employed, and the intricate oxidative stress connected network, among others. Collectively, these factors will be explored in this review article to decipher the observed shortcomings in the application of antioxidant therapies within clinical settings.

Screening and Exploring the Application of the Multifunctional Antioxidant Peptides MSWLC and TSWLC

In this study, an antioxidant pentapeptide library is created based on antioxidant characteristics. The peptides are then purified and separated using liquid chromatography/mass spectrometry (LC/MS) and time-of-flight mass spectrometry (TOF). Chemical evaluations identify four peptides with excellent antioxidant activity. The four peptides undergo biocompatibility testing with L-929, NIH 3T3, and Hep-G2 cells. A model of hydrogen peroxide-induced cellular damage in G2 cells shows the peptides' protective and reparative effects against oxidative damage. Two peptides, MSWLC and TSWLC, which perform best overall, are chosen for further analysis. To explore the peptides' potential multifunctionality, acute liver inflammation, keratitis, and aging models are established in mice. MSWLC and TSWLC demonstrate anti-inflammatory and anti-aging properties. An antioxidant emulsion prepared by emulsification is found to be non-irritant in a mouse skin irritation test. In a mouse model exposed to ultraviolet radiation, the sunscreen exhibits excellent UV protection and antioxidant effects. These peptides possess potent antioxidant properties and multifunctionality, indicating broad application potential.

Unraveling the molecular and immunological landscape: Exploring signaling pathways in osteoporosis

Osteoporosis, characterized by compromised bone density and microarchitecture, represents a significant global health challenge, particularly in aging populations. This comprehensive review delves into the intricate signaling pathways implicated in the pathogenesis of osteoporosis, providing valuable insights into the pivotal role of signal transduction in maintaining bone homeostasis. The exploration encompasses cellular signaling pathways such as Wnt, Notch, JAK/STAT, NF-κB, and TGF-β, all of which play crucial roles in bone remodeling. The dysregulation of these pathways is a contributing factor to osteoporosis, necessitating a profound understanding of their complexities to unveil the molecular mechanisms underlying bone loss. The review highlights the pathological significance of disrupted signaling in osteoporosis, emphasizing how these deviations impact the functionality of osteoblasts and osteoclasts, ultimately resulting in heightened bone resorption and compromised bone formation. A nuanced analysis of the intricate crosstalk between these pathways is provided to underscore their relevance in the pathophysiology of osteoporosis. Furthermore, the study addresses some of the most crucial long non-coding RNAs (lncRNAs) associated with osteoporosis, adding an additional layer of academic depth to the exploration of immune system involvement in various types of osteoporosis. Finally, we propose that SKP1 can serve as a potential biomarker in osteoporosis.

Effectiveness of anthocyanin-containing foods and nutraceuticals in mitigating oxidative stress, inflammation, and cardiovascular health-related biomarkers: a systematic review of animal and human interventions

Cardiovascular diseases (CVDs) are a group of chronic health disorders prevalent worldwide that claim millions of lives yearly. Inflammation and oxidative stress are intricately associated with myocardial tissue damage, endothelial dysfunction, and increased odds of heart failure. Thus, dietary strategies aimed at decreasing the odds of CVDs are paramount. In this regard, the consumption of anthocyanins, natural pigments found in edible flowers, fruits, and vegetables, has attracted attention due to their potential to promote cardiovascular health. The main mechanisms of action linked with their protective effects on antioxidant and anti-inflammatory activities, serum lipid profile modulation, and other cardiovascular health parameters are explained and exemplified. However, little is known about the dose-dependency nature of the effects, which anthocyanin has better efficiency, and whether anthocyanin-containing foods display better in vivo efficacy than nutraceuticals (i.e., concentrated extracts containing higher levels of anthocyanins than foods). Thus, this systematic review focused on determining the effects of anthocyanin-containing foods and nutraceuticals on biomarkers associated with CVDs using animal studies and human interventions supported by in vitro mechanistic insights. Overall, the results showed that the regular consumption of anthocyanin-containing foods and nutraceuticals improved vascular function, lipid profile, and antioxidant and anti-inflammatory effects. The daily dosage, the participants' health status, and the duration of the intervention also significantly influenced the results.

Physicochemical, Rheological and Sensory Evaluation of Herbal Bread Containing Turmeric, Ginger, and Black Cumin Powder

The diversity in the global food market is expanding as thousands of new products enter the business every year, among which nutraceutical and functional foods hold important positions. The present research work aimed at the nutritional evaluation of three medicinal herbs, i.e., turmeric (Curcuma longa L.), ginger (Zingiber officinale), and black cumin (Nigella sativa). A bread formulation was enriched with the individual/combined supplementation (1-3%) of these herbs. Later, the bread was analyzed for nutritional, rheological, textural, and sensorial characteristics. The results revealed that the herbs improved the nutritional composition of bread, especially ash and fiber, as the maximum ash and fiber contents were noticed in T15 (2.0% dried powder of each plant) with values of 1.64 ± 0.04% and 4.63 ± 0.16%, respectively. The results regarding the rheological behavior showed minor variations in the rheological traits and a slight increase in dough development time up to 4.50 ± 0.20 min in T10 from 2.80 ± 0.13 min in T0. The sensorial attributes also indicated their marked suitability as external and internal characteristics were least affected by the addition of the herbs. Although some parameters like the crust and crumb colors were affected by the addition of black cumin, showing values of 6.25 ± 0.52 and 4.44 ± 0.19, respectively, in T15, and aroma characteristics were affected by the addition of ginger, supplementation with a combination of herbs at lower doses mitigated the adverse effects of other herbs. Moreover, shelf-life extension, especially with the addition of turmeric powder, was the hallmark of this research. This study concluded that medicinal herbs can be incorporated into baked products to improve the nutritional and sensorial attributes of functional herbal bread.

Lanthanide-Doped ZnO Nanoparticles: Unraveling Their Role in Cytotoxicity, Antioxidant Capacity, and Nanotoxicology

This study used a sonochemical synthesis method to prepare (La, Sm)-doped ZnO nanoparticles (NPs). The effect of incorporating these lanthanide elements on the structural, optical, and morphological properties of ZnO-NPs was analyzed. The cytotoxicity and the reactive oxygen species (ROS) generation capacity of ZnO-NPs were evaluated against breast (MCF7) and colon (HT29) cancer cell lines. Their antioxidant activity was analyzed using a DPPH assay, and their toxicity towards Artemia salina nauplii was also evaluated. The results revealed that treatment with NPs resulted in the death of 10.559-42.546% and 18.230-38.643% of MCF7 and HT29 cells, respectively. This effect was attributed to the ability of NPs to downregulate ROS formation within the two cell lines in a dose-dependent manner. In the DPPH assay, treatment with (La, Sm)-doped ZnO-NPs inhibited the generation of free radicals at IC50 values ranging from 3.898 to 126.948 μg/mL. Against A. salina nauplii, the synthesized NPs did not cause death nor induce morphological changes at the tested concentrations. A series of machine learning (ML) models were used to predict the biological performance of (La, Sm)-doped ZnO-NPs. Among the designed ML models, the gradient boosting model resulted in the greatest mean absolute error (MAE) (MAE 9.027, R2 = 0.86). The data generated in this work provide innovative insights into the influence of La and Sm on the structural arrangement and chemical features of ZnO-NPs, together with their cytotoxicity, antioxidant activity, and in vivo toxicity.

Interplay of oxidative stress, cellular communication and signaling pathways in cancer

Cancer remains a significant global public health concern, with increasing incidence and mortality rates worldwide. Oxidative stress, characterized by the production of reactive oxygen species (ROS) within cells, plays a critical role in the development of cancer by affecting genomic stability and signaling pathways within the cellular microenvironment. Elevated levels of ROS disrupt cellular homeostasis and contribute to the loss of normal cellular functions, which are associated with the initiation and progression of various types of cancer. In this review, we have focused on elucidating the downstream signaling pathways that are influenced by oxidative stress and contribute to carcinogenesis. These pathways include p53, Keap1-NRF2, RB1, p21, APC, tumor suppressor genes, and cell type transitions. Dysregulation of these pathways can lead to uncontrolled cell growth, impaired DNA repair mechanisms, and evasion of cell death, all of which are hallmark features of cancer development. Therapeutic strategies aimed at targeting oxidative stress have emerged as a critical area of investigation for molecular biologists. The objective is to limit the response time of various types of cancer, including liver, breast, prostate, ovarian, and lung cancers. By modulating the redox balance and restoring cellular homeostasis, it may be possible to mitigate the damaging effects of oxidative stress and enhance the efficacy of cancer treatments. The development of targeted therapies and interventions that specifically address the impact of oxidative stress on cancer initiation and progression holds great promise in improving patient outcomes. These approaches may include antioxidant-based treatments, redox-modulating agents, and interventions that restore normal cellular function and signaling pathways affected by oxidative stress. In summary, understanding the role of oxidative stress in carcinogenesis and targeting this process through therapeutic interventions are of utmost importance in combating various types of cancer. Further research is needed to unravel the complex mechanisms underlying oxidative stress-related pathways and to develop effective strategies that can be translated into clinical applications for the management and treatment of cancer. Video Abstract.

Chemical Composition and Biological Properties of New Romanian Lavandula Species

The aims of the present study were to evaluate for the first time the chemical composition and antioxidant, antibacterial, antifungal and antiproliferative potentials of the Romanian George 90 lavender species, as well as parental species, L. angustifolia and L. latifolia. The L. angustifolia, L. latifolia and George 90 essential oils were analyzed by GC-MS/MS and the L. angustifolia, L. latifolia and George 90 hydroalcoholic extracts were analyzed by HPLC-DAD. The antioxidant, antibacterial, antifungal and antiproliferative assays revealed that all the investigated species showed significant activities. The results highlighted the chemical composition and the promising biological potentials of the L. angustifolia, L. latifolia and George 90 lavender species, validating their ethnomedicinal value, which offers potential applications as natural drugs.

Recent Progress in Distiller's Grains: Chemical Compositions and Biological Activities

Distiller's grains (DGs) are solid mixtures that remain after the production of alcoholic beverages. A large amount of DGs is produced each year during the brewing process. Currently, they are mostly used as a feedstock or substrate in the feed industry. However, the lack of a comprehensive understanding of the chemical composition of DGs is a major constraint on their further development and application for high-value-added usages. Some studies were published on the bioactive constituents of DGs in several different types of journals. Data were therefore collated to provide a comprehensive overview of these natural products. DGs are rich in phenols, phytosterols, and fatty acids, in addition to general lipid and protein constituents. These compounds and their related extracts possess diverse biological activities, including antioxidant, anti-inflammatory, and anti-hyperglycaemic effects. We hope that this review will provide research incentives for the further development and utilisation of DGs to develop high-value-added products.

Molecular and Cellular Mechanisms of Osteoporosis

Osteoporosis is a widespread systemic disease characterized by a decrease in bone mass and an imbalance of the microarchitecture of bone tissue. Experimental and clinical studies devoted to investigating the main pathogenetic mechanisms of osteoporosis revealed the important role of estrogen deficiency, inflammation, oxidative stress, cellular senescence, and epigenetic factors in the development of bone resorption due to osteoclastogenesis, and decreased mineralization of bone tissue and bone formation due to reduced function of osteoblasts caused by apoptosis and age-depended differentiation of osteoblast precursors into adipocytes. The current review was conducted to describe the basic mechanisms of the development of osteoporosis at molecular and cellular levels and to elucidate the most promising therapeutic strategies of pathogenetic therapy of osteoporosis based on articles cited in PubMed up to September 2023.

From Tea to Health: Exploring Abrus mollis for Liver Protection and Unraveling Its Potential Mechanisms

Abrus mollis Hance is a characteristic medicinal herb which is used in Guangdong and Guangxi provinces of China for making soup, medicinal meals, and herbal tea to treat dampheat jaundice and rib discomfort. Current phytochemical study on A. mollis led to the isolation of four new flavones, mollisone A-D (1-4), and thirty two known compounds (5-36). Their structures were characterized by an extensive analysis of spectroscopic data including IR, UV, HR-ESI-MS, and 1D and 2D NMR, as well as electronic circular dichroism calculation. In addition, in order to initially understand their biological activities for traditional applications, in vitro antioxidant and hepatoprotective tests were carried out, whose results illustrated that 25 compounds had significant free radical scavenging ability, and compounds 13 and 16 exhibited protective activities on D-GalN-induced LO2 cell damage than the positive control. Moreover, network pharmacological analysis revealed that the hepatoprotective activity of A. mollis involved multitargets and multipathways such as PI3K/Akt, MAPK, and JAK-STAT pathways and various biological processes such as positive regulation of phosphorylation and regulation of kinase activity. These results suggested that this species could serve as a potential hepatoprotective agent for functional food or medicinal use.

Immunohistochemical Expression of Glutathione Peroxidase-2 (Gpx-2) and Its Clinical Relevance in Colon Adenocarcinoma Patients

Glutathione peroxidase 2 (Gpx-2) is a selenoenzyme with antioxidant capabilities that may play a role in cancer development. Hence, we investigated the immunohistochemical expression of Gpx-2 protein in colon adenocarcinoma samples derived from patients with colon adenocarcinoma who did not receive any form of treatment prior to the surgical procedure. The associations between the immunohistochemical expression of Gpx-2 and clinical parameters were analysed using the Chi2 test and Fisher's exact test. A Kaplan-Meier analysis and the log-rank test were used to verify the relationship between the intensity of Gpx-2 expression and the 5-year survival rate of patients. In total, 101 (80.80%) samples had strong Gpx-2 protein expression and 24 (19.20%) samples were characterized with low expression. The high expression of Gpx-2 was correlated with the histological grade of the tumour (p < 0.001), PCNA immunohistochemical expression (p < 0.001), depth of invasion (p = 0.001) and angioinvasion (p < 0.001). We can conclude that high expression of Gpx-2 is correlated with reduced survival of colon adenocarcinoma patients (log-rank, p < 0.001).

Research Progress of SERS Sensors Based on Hydrogen Peroxide and Related Substances

Hydrogen peroxide (H2O2) has an important role in living organisms, and its detection is of great importance in medical, chemical, and food safety applications. This review provides a comparison of different types of Surface-enhanced Raman scattering (SERS) sensors for H2O2 and related substances with respect to their detection limits, which are of interest due to high sensitivity compared to conventional sensors. According to the latest research report, this review focuses on the sensing mechanism of different sensors and summarizes the linear range, detection limits, and cellular applications of new SERS sensors, and discusses the limitations in vivo and future prospects of SERS technology for the detection of H2O2.

Glutathione: Lights and Shadows in Cancer Patients

In cases of cellular injury, there is an observed increase in the production of reactive oxygen species (ROS). When this production becomes excessive, it can result in various conditions, including cancerogenesis. Glutathione (GSH), the most abundant thiol-containing antioxidant, is fundamental to re-establishing redox homeostasis. In order to evaluate the role of GSH and its antioxi-dant effects in patients affected by cancer, we performed a thorough search on Medline and EMBASE databases for relevant clinical and/or preclinical studies, with particular regard to diet, toxicities, and pharmacological processes. The conjugation of GSH with xenobiotics, including anti-cancer drugs, can result in either of two effects: xenobiotics may lose their harmful effects, or GSH conjugation may enhance their toxicity by inducing bioactivation. While being an interesting weapon against chemotherapy-induced toxicities, GSH may also have a potential protective role for cancer cells. New studies are necessary to better explain the relationship between GSH and cancer. Although self-prescribed glutathione (GSH) implementation is prevalent among cancer patients with the intention of reducing the toxic effects of anticancer treatments and potentially preventing damage to normal tissues, this belief lacks substantial scientific evidence for its efficacy in reducing toxicity, except in the case of cisplatin-related neurotoxicity. Therefore, the use of GSH should only be considered under medical supervision, taking into account the appropriate timing and setting.

Distinct Role of Lycium barbarum L. Polysaccharides in Oxidative Stress-Related Ocular Diseases

Oxidative stress is an imbalance between the increased production of reactive species and reduced antioxidant activity, which can cause a variety of disturbances including ocular diseases. Lycium barbarum polysaccharides (LBPs) are complex polysaccharides isolated from the fruit of L. barbarum, showing distinct roles in antioxidants. Moreover, it is relatively safe and non-toxic. In recent years, the antioxidant activities of LBPs have attracted remarkable attention. In order to illustrate its significance and underlying therapeutic value for vision, we comprehensively review the recent progress on the antioxidant mechanisms of LBP and its potential applications in ocular diseases, including diabetic retinopathy, hypertensive neuroretinopathy, age-related macular degeneration, retinitis pigmentosa, retinal ischemia/reperfusion injury, glaucoma, dry eye syndrome, and diabetic cataract.