Iron-binding and anti-Fenton properties of baicalein and baicalin

Therapeutic potential of synthetic and natural iron chelators against ferroptosis

Ferroptosis, a regulated form of cell death, is characterized by iron accumulation that results in the production of reactive oxygen species. This further causes lipid peroxidation and damage to the cellular components, eventually culminating into oxidative stress. Recent studies have highlighted the pivotal role of ferroptosis in the pathophysiological development and progression of various diseases such as β-thalassemia, hemochromatosis, and neurodegenerative disorders like AD and PD. Extensive efforts are in progress to understand the molecular mechanisms governing the role of ferroptosis in these conditions, and chelation therapy stands out as a potential approach to mitigate ferroptosis and its related implications in their development. There are currently both synthetic and natural iron chelators that are being researched for their potential as ferroptosis inhibitors. While synthetic chelators are relatively well-established and studied, their short plasma half-life and toxic side effects necessitate the exploration and identification of natural products that can act as efficient and safe iron chelators. In this review, we comprehensively discuss both synthetic and natural iron chelators as potential therapeutic strategies against ferroptosis-induced pathologies.

Characterization of 37 enological tannins using a multiple technique approach: Linear sweep voltammetry as a rapid method both for classification and determination of antioxidant properties

In this work, 37 enological tannins of different classes were studied to investigate whether linear sweep voltammetry (LSV) could be a method to determine the family of a sample and its antioxidant capacity. A "wholistic" approach was used, combining LSV data with nuclear magnetic resonance (NMR), polyphenol quantification (Folin-Ciocalteu method and gravimetric analysis), antiradical activity (DPPH assay), and reducing capacity (FRAP assay). Voltammetric data were processed with statistical techniques and the results show the clustering of tannins in three different classes: ellagitannins, gallotannins, and condensed tannins. These findings were confirmed by NMR data treated with the same procedure. Finally, ellagitannins showed a high reducing capacity and gallotannins showed a high antiradical capacity. Importantly, LSV indices were shown to be significantly correlated with DPPH and FRAP parameters. Therefore, the hypothesis of LSV as a potentially useful technique to choose the most suitable tannin for a determined antioxidant purpose was successfully proved.

Multi-target macrocycles: pyrogallol derivatives to control multiple pathological factors associated with Alzheimer's disease

Designing multi-target chemical tools is a vital approach to understanding the pathology of Alzheimer's disease (AD), which involves a complex network of pathological factors, such as free organic radicals, amyloid-β (Aβ), and metal-bound Aβ (metal-Aβ). The pyrogallol moiety, known for its ability to lower redox potentials and interact with both Aβ and metal ions, presents a promising framework for this molecular design. Here we show how simple structural variations of pyrogallol can be used to enhance its ability to scavenge free organic radicals and regulate the aggregation of both metal-free Aβ and metal-Aβ. By incorporating multiple pyrogllol units into a macrocyclic scaffold via methylene bridges, we achieve synergistic reactivity against several pathological targets. Our structure-reactivity relationship studies also reveal that the macrocyclic structure noticeably improves antioxidant activity as well as interactions with both Aβ and metal ions, leading to oxidation of Aβ peptides and influencing their conformation and aggregation in both the absence and presence of metal ions. This work demonstrates the potential of simple redox-active structural entities in developing multifunctional chemical reagents that effectively manage the pathological components associated with AD.

Conjugates of amiridine and salicylic derivatives as promising multifunctional CNS agents for potential treatment of Alzheimer's disease

New conjugates of amiridine and salicylic derivatives (salicylamide, salicylimine, and salicylamine) with different lengths of alkylene spacers were designed, synthesized, and evaluated as potential multifunctional central nervous system therapeutic agents for Alzheimer's disease (AD). Conjugates demonstrated high acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition (IC50: AChE, 0.265-4.24 μM; BChE, 0.01-0.64 μM) but poor activity against off-target carboxylesterase (CES). Specifically, conjugates with a (CH2)8 spacer showed the highest AChE and BChE inhibition: 3-16 times more effective than amiridine. Salicylamides 7b and 7c had the maximum BChE/AChE selectivity ratios: 193 and 138, respectively. Conjugates were mixed-type reversible inhibitors of both cholinesterases and displaced propidium from the AChE peripheral anionic site (PAS) at the level of donepezil. All conjugates inhibited Aβ42 self-aggregation in the thioflavin test; inhibition increased with spacer elongation, being greatest for (CH2)8. The results agreed with molecular docking to AChE, BChE, and Aβ42. Conjugates exhibited high 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS)•+-scavenging activity comparable to the standard antioxidant Trolox, and they showed the ability to bind Cu2+, Fe2+, and Zn2+. Conjugates had favorable predicted intestinal absorption and blood-brain barrier permeability. Altogether, the results indicate that the new conjugates possess potential for further development as multifunctional anti-AD drug candidates.

Exploring baicalein: A natural flavonoid for enhancing cancer prevention and treatment

Despite years of development in cancer therapy, achieving successful cancer treatment remains a major research topic. Primary means of cancer treatment include chemotherapy, radiotherapy, and surgery. However, these modalities are associated with limitations and adverse effects on normal tissues. Therefore, there is a search for novel therapeutic approaches that will increase the efficacy of the available treatment while minimizing side effects. Naturally occurring bioactive chemicals such as flavonoids have long been used in traditional medicine to treat various illnesses. Baicalein, an active ingredient in Scutellaria baicalensis Georgi, is utilised in traditional medicine to treat conditions such as hypertension, cardiovascular disease, inflammation, and infections. This review focuses on summarizing the data available on cancer prevention and treatment usage of baicalein. Baicalein is thought to prevent cancer progression by inducing apoptosis, autophagy, and genome instability, and its ability to promote chemo-potentiation, anti-metastatic effects, and regulate specific signalling molecules and transcription factors. Baicalein can be a promising option for cancer treatment, either alone or in combination with established anticancer drugs.

Ferroptosis: a new mechanism of traditional Chinese medicine for treating hematologic malignancies

Ferroptosis is a recently identified form of cell death characterized by lipid peroxidation and elevated iron levels. It is closely associated with hematologic malignancies, including leukemia, multiple myeloma (MM), and myelodysplastic syndromes (MDS). Research indicates that ferroptosis could represent a novel therapeutic target for these hematologic malignancies. Furthermore, traditional Chinese medicine (TCM) has been shown to modulate hematologic malignancies through the ferroptosis pathway. This paper aims to elucidate the mechanisms underlying ferroptosis and summarize the current research advancements regarding ferroptosis in hematologic malignancies, as well as the role of traditional Chinese medicine in the prevention and treatment of ferroptosis, with the goal of enhancing treatment efficacy.

The metabolites from traditional Chinese medicine targeting ferroptosis for cancer therapy

Cancer is a major disease with ever-increasing morbidity and mortality. The metabolites derived from traditional Chinese medicine (TCM) have played a significant role in combating cancers with curative efficacy and unique advantages. Ferroptosis, an iron-dependent programmed death characterized by the accumulation of lipid peroxide, stands out from the conventional forms of cell death, such as apoptosis, pyroptosis, necrosis, and autophagy. Recent evidence has demonstrated the potential of TCM metabolites targeting ferroptosis for cancer therapy. We collected and screened related articles published in or before June 2023 using PubMed, Google Scholar, and Web of Science. The searched keywords in scientific databases were ferroptosis, cancer, tumor, traditional Chinese medicine, botanical drugs, and phytomedicine. Only research related to ferroptosis, the metabolites from TCM, and cancer was considered. In this review, we introduce an overview of the current knowledge regarding the ferroptosis mechanisms and review the research advances on the metabolites of TCM inhibiting cancer by targeting ferroptosis.

5,7-dihydroxy-3',4',5'-trimethoxyflavone mitigates lead induced neurotoxicity in rats via its chelating, antioxidant, anti-inflammatory and monoaminergic properties

Chronic exposure to lead (Pb) induces neurodegenerative changes in animals and humans. Drugs with strong antioxidant properties are effective against Pb-mediated neurotoxicity. In a prior study, we identified 5,7-dihydroxy-3',4',5'-trimethoxyflavone (TMF) from Ocimum basilicum L. leaves as a potent antioxidant and neuroprotective compound. This research explores TMF's neuroprotective effects against Pb-induced brain toxicity in rats to establish it as a therapeutic agent. Rats received lead acetate (100 mg/kg, orally, once daily) for 30 days to induce brain injury, followed by TMF treatment (5 and 10 mg/kg, oral, once daily) 30 min later. Cognitive and motor functions were assessed using Morris Water Maze and horizontal bar tests. Lead, monoamine oxidase (MAO) A and B enzymes, reduced glutathione (GSH), thiobarbituric acid reactive species (TBARS), Tumor necrosis factor-alpha (TNF-α), and IL-6 levels were measured in the hippocampus and cerebellum. Pb exposure impaired cognitive and motor functions, increased Pb, TBARS, TNF-α, and IL-6 levels, and compromised MAO A & B and GSH levels. TMF reversed Pb-induced memory and motor deficits and normalized biochemical anomalies. TMF's neuroprotective effects against lead involve chelating, antioxidant, anti-inflammatory, and monoaminergic properties, suggesting its potential as a treatment for metal-induced brain injury.

Mechanisms of polyphenols on quality control of aquatic products in storage: A review

Aquatic products are easily spoiled during storage due to oxidation, endogenous enzymes, and bacteria. At the same time, compared with synthetic antioxidants, based on the antibacterial and antioxidant mechanism of biological agents, the development of natural, nontoxic, low-temperature, better-effect green biological preservatives is more acceptable to consumers. The type and molecular structure of polyphenols affect their antioxidant and antibacterial effectiveness. This review will describe how they achieve their antioxidant and antibacterial effects. And the recent literature on the mechanism and application of polyphenols in the preservation of aquatic products was updated and summarized. The conclusion is that in aquatic products, polyphenols alleviate lipid oxidation, protein degradation and inhibit the growth and reproduction of microorganisms, so as to achieve the effect of storage quality control. And put forward suggestions on the application of the research results in aquatic products. We hope to provide theoretical support for better exploration of the application of polyphenols and aquatic product storage.

Application of natural products in regulating ferroptosis in human diseases

BACKGROUND

Ferroptosis is a type of cell death caused by excessive iron-induced peroxidation. It has been found to be involved in a variety of diseases, and natural products can be used to target ferroptosis in treatments. Natural products are biologically active compounds extracted or synthesized from nature. It is an important resource for the discovery of skeletons with a high degree of structural diversity and a wide range of bioactivities, which can be developed directly or used as a starting point for the optimization of new drugs.

PURPOSE

In this review, we aim to discuss the interactions between natural products and ferroptosis in the treatment of human diseases.

METHODS

Literature was searched in Pubmed, Science Direct, and Web of Science databases for the 11-year period from 2012 to 2023 using the search terms "natural products", "ferroptosis", "human disease", "neurodegenerative disease", "cardiovascular disease", and "cancer".

RESULTS

In this research, the roles of natural products and ferroptosis were investigated. We suggest that natural products, such as terpenoids, flavonoids, polyphenols, alkaloids, and saponins, can be used in therapeutic applications for human diseases, as well as in ferroptosis. Additionally, the main mechanisms of ferroptosis were summarized and discussed. Furthermore, we propose that natural products can be utilized to enhance the sensitivity of cancer cells to ferroptosis, thus helping to overcome drug resistance and inhibit metastasis. Moreover, natural products have the potential to modulate the expression levels of ferroptosis-related factors. Finally, the future directions of this field were highlighted.

CONCLUSION

The potential of natural products which focus on ferroptosis to treat human illnesses, particularly cancer, is very encouraging for human wellbeing.

Regulatory potential of secondary metabolite DIMBOA and baicalein to imazethapyr-induced toxicity in wheat seedlings

Controlling and mitigating the toxicity of herbicides to non-target plants is of significant importance in reducing ecological risks. The development of green and natural herbicide control technologies has become an urgent necessity. In this paper, how 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazine-3(4H)-one (DIMBOA) and baicalein alleviated oxidative stress induced by imazethapyr (IM) in wheat seedlings was investigated. We found that DIMBOA and baicalein enhanced the antioxidant enzyme activities in wheat seedlings exposed to IM and reduced the excessive reactive oxygen species due to IM stress by 21.3% and 23.5%, respectively. DIMBOA and baicalein also restored the iron content reduced by IM and effectively mitigated Fe2+ overload by alleviating the response of heme oxygenase 1 to IM stress. The antioxidant and iron homeostatic maintenance properties of DIMBOA and baicalein enhanced the defenses of wheat seedlings against IM stress. Our results highlight the potential implication of secondary metabolites as natural products to modulate herbicide toxicity to non-target plants.

Natural products and the balancing act of autophagy-dependent/independent ferroptosis in cancer therapy

The control of biological cell death is essential for the body's appropriate growth. The resistance of cells to the apoptotic process presents a new difficulty in the treatment of cancer. To combat cancer cells, researchers are working to find new apoptotic pathways and components to activate. One of the processes of regulated cell death (RCD) is referred to as ferroptosis marked by a decline in the activity of lipid glutathione peroxidase 4 (GPX4) after the buildup of reactive oxygen species (ROS). Since lipid peroxidation is a crucial component of ferroptosis and is required for its start, numerous medicines have been studied, particularly for the treatment of cancer. In this context, autophagy is an additional form of RCD that can govern ferroptosis through shared signaling pathways/factors involved in both mechanisms. In this review, we will explore the molecular mechanisms underlying ferroptosis and its association with autophagy, to gain fresh insights into their interplay in cancer advancement, and the potential of natural products for its treatment.

Pathophysiological aspects of transferrin-A potential nano-based drug delivery signaling molecule in therapeutic target for varied diseases

Transferrin (Tf), widely known for its role as an iron-binding protein, exemplifies multitasking in biological processes. The role of Tf in iron metabolism involves both the uptake of iron from Tf by various cells, as well as the endocytosis mediated by the complex of Tf and the transferrin receptor (TfR). The direct conjugation of the therapeutic compound and immunotoxin studies using Tf peptide or anti-Tf receptor antibodies as targeting moieties aims to prolong drug circulation time and augment efficient cellular drug uptake, diminish systemic toxicity, traverse the blood-brain barrier, restrict systemic exposure, overcome multidrug resistance, and enhance therapeutic efficacy with disease specificity. This review primarily discusses the various biological actions of Tf, as well as the development of Tf-targeted nano-based drug delivery systems. The goal is to establish the use of Tf as a disease-targeting component, accentuating the potential therapeutic applications of this protein.

Targeting ferroptosis unveils a new era for traditional Chinese medicine: a scientific metrology study

In the past 11 years, there has been a surge in studies exploring the regulatory effect of Traditional Chinese Medicine (TCM) on ferroptosis. However, a significant gap persists in comprehensive scientometric analysis and scientific mapping research, especially in tracking the evolution, primary contributors, and emerging research focal points. This study aims to comprehensively update the advancements in targeting ferroptosis with various TCMs during the previous 11 years. The data, covering the period from 1 January 2012, to 30 November 2023, were retrieved from the Web of Science database. For in-depth scientometric and visualized analyses, a series of advanced analytical instruments were employed. The findings highlight China's predominant role, accounting for 71.99% of total publications and significantly shaping research in this domain. Noteworthy productivity was observed at various institutions, including Guangzhou University of Chinese Medicine, Chengdu University of Traditional Chinese Medicine, and Zhejiang University. Thomas Efferth emerged as the foremost author within this field, while Frontiers in Pharmacology boasted the highest publication count. This study pinpointed hepatocellular carcinoma, chemical and drug-induced liver injury, mitochondrial diseases, acute kidney injury, and liver failure as the most critical disorders addressed in this research realm. The research offers a comprehensive bibliometric evaluation, enhancing our understanding of the present status of TCM therapy in managing ferroptosis-related diseases. Consequently, it aids both seasoned researchers and newcomers by accelerating access to vital information and fostering innovative concept extraction within this specialized field.

A Multifunctional Liposome for Synergistic Chemotherapy with Ferroptosis Activation of Triple-Negative Breast Cancer

There is an urgent need to develop efficient treatments for highly invasive triple-negative breast cancer (TNBC) with a high rate of postoperative. Baicalin (BA) has shown inhibitory effects on several tumor cells and could activate ferroptosis in some tumor cells by producing reactive oxygen species (ROS). For overcoming the shortcomings of BA in clinical applications and enhancing the effect of ferroptosis in TNBC, herein, a multifunctional liposome (BA-Fe(III) coordination-polymer-loaded liposome, BA-Fe(III) Lipo) was developed for synergistic chemotherapy of TNBC with ferroptosis activation. Fe(III) released from BA-Fe(III) Lipo could be efficiently reduced to Fe(II) in the presence of high glutathione in tumor microenvironment, which in turn catalyzed the oxidation of unsaturated fats through lipid peroxidation for more ROS production. In addition, BA-Fe(III) Lipo activated tumor cell ferroptosis by down-regulating the enzymatic activity of ferritin heavy chain 1 protein and glutathione peroxidase. This study provided a novel therapeutic strategy for the treatment of TNBC by ingeniously combining chemotherapy with the activation of ferroptosis, which presented potential clinical applications.

Complexation of Flavonoids: Spectral Phenomena, Regioselectivity, Interplay with Charge and Proton Transfer

The review compiles information on the spectral classification of flavonoids, the changes in their electronic structure upon complex formation, and the manifestation of these changes in the absorption and emission spectra. Part of the review is devoted to the regioselectivity of the complex formation process, including types of complexation sites, the structure of chelates and 'open' complexes, and the correlation between the structure of complexes and their spectral properties. The interplay between complex formation and other processes occurring in flavonoids during electronic excitation is also considered, such as intramolecular inter-fragment charge transfer (ICT) and intramolecular proton transfer (ESIPT). The review also contains systematic data on the study of regioselectivity and spectral properties of flavone complexes, obtained by the author and their colleagues over the past decades.

Role of Flavonoids in Modulation of Mitochondria Dynamics during Oxidative Stress

BACKGROUND

Flavonoids are a widespread category of naturally occurring polyphenols distinguished by the flavan nucleus in plant-based foods and beverages, known for their various health benefits. Studies have suggested that consuming 150-500 mg of flavonoids daily is beneficial for health. Recent studies suggest that flavonoids are involved in maintaining mitochondrial activity and preventing impairment of mitochondrial dynamics by oxidative stress.

OBJECTIVE

This review emphasized the significance of studying the impact of flavonoids on mitochondrial dynamics, oxidative stress, and inflammatory response.

METHODS

This review analysed and summarised the findings related to the impact of flavonoids on mitochondria from publicly available search engines namely Pubmed, Scopus, and Web of Science.

DESCRIPTION

Any disruption in mitochondrial dynamics can contribute to cellular dysfunction and diseases, including cancer, cardiac conditions, and neurodegeneration. Flavonoids have been shown to modulate mitochondrial dynamics by regulating protein expression involved in fission and fusion events. Furthermore, flavonoids exhibit potent antioxidant properties by lowering the production of ROS and boosting the performance of antioxidant enzymes. Persistent inflammation is a characteristic of many different disorders. This is because flavonoids also alter the inflammatory response by controlling the expression of numerous cytokines and chemokines involved in the inflammatory process. Flavonoids exhibit an impressive array of significant health effects, making them an effective therapeutic agent for managing various disorders. Further this review summarised available mechanisms underlying flavonoids' actions on mitochondrial dynamics and oxidative stress to recognize the optimal dose and duration of flavonoid intake for therapeutic purposes.

CONCLUSION

This review may provide a solid foundation for developing targeted therapeutic interventions utilizing flavonoids, ultimately benefiting individuals afflicted with various disorders.

Beyond ferrostatin-1: a comprehensive review of ferroptosis inhibitors

Ferroptosis is an iron-catalysed form of regulated cell death, which is critically dependent on phospholipid peroxidation of cellular membranes. Ferrostatin 1 was one of the first synthetic radical-trapping antioxidants (RTAs) reported to block ferroptosis and it is widely used as reference compound. Ferroptosis has been linked to multiple diseases and the use of its inhibitors could have therapeutic potential. Although, novel biochemical pathways provide insights for different pharmacological targets, the use of lipophilic RTAs to block ferroptosis remains superior. In this Review, we provide a comprehensive overview of the different classes of ferroptosis inhibitors, focusing on endogenous and synthetic RTAs. A thorough analysis of their chemical, pharmacokinetic, and pharmacological properties and potential for in vivo use is provided.

Herbal and Natural Treatments for the Management of the Glaucoma: An Update

Glaucoma causes the degeneration of the retinal ganglion cells (RGCs) and their axons, inducing a tissue reshaping that affects both the retina and the optic nerve head. Glaucoma care especially focuses on reducing intraocular pressure, a significant risk factor for progressive damage to the optic nerve. The use of natural treatments, such as herbs, vitamins, and minerals, is becoming increasingly popular today. While plants are a rich source of novel biologically active compounds, only a small percentage of them have been phytochemically examined and evaluated for their medicinal potential. It is necessary for eye care professionals to inform their glaucoma patients about the therapy, protection, and efficacy of commonly used herbal medicines, considering the widespread use of herbal medicines. The purpose of this review is to examine evidence related to the most widely used herbal medicines for the management and treatment of glaucoma, to better understand the potential benefits of these natural compounds as supplementary therapy.

Therapeutic Approaches Targeting Ferroptosis in Cardiomyopathy

The term cardiomyopathy refers to a group of heart diseases that cause severe heart failure over time. Cardiomyopathies have been proven to be associated with ferroptosis, a non-apoptotic form of cell death. It has been shown that some small molecule drugs and active ingredients of herbal medicine can regulate ferroptosis, thereby alleviating the development of cardiomyopathy. This article reviews recent discoveries about ferroptosis, its role in the pathogenesis of cardiomyopathy, and the therapeutic options for treating ferroptosis-associated cardiomyopathy. The article aims to provide insights into the basic mechanisms of ferroptosis and its treatment to prevent cardiomyopathy and related diseases.

Emerging significance and therapeutic targets of ferroptosis: a potential avenue for human kidney diseases

Kidney diseases remain one of the leading causes of human death and have placed a heavy burden on the medical system. Regulated cell death contributes to the pathology of a plethora of renal diseases. Recently, with in-depth studies into kidney diseases and cell death, a new iron-dependent cell death modality, known as ferroptosis, has been identified and has attracted considerable attention among researchers in the pathogenesis of kidney diseases and therapeutics to treat them. The majority of studies suggest that ferroptosis plays an important role in the pathologies of multiple kidney diseases, such as acute kidney injury (AKI), chronic kidney disease, and renal cell carcinoma. In this review, we summarize recently identified regulatory molecular mechanisms of ferroptosis, discuss ferroptosis pathways and mechanisms of action in various kidney diseases, and describe the protective effect of ferroptosis inhibitors against kidney diseases, especially AKI. By summarizing the prominent roles of ferroptosis in different kidney diseases and the progress made in studying ferroptosis, we provide new directions and strategies for future research on kidney diseases. In summary, ferroptotic factors are potential targets for therapeutic intervention to alleviate different kidney diseases, and targeting them may lead to new treatments for patients with kidney diseases.

Sepsis-mediated renal dysfunction: Pathophysiology, biomarkers and role of phytoconstituents in its management

Sepsis has evolved as an enormous health issue amongst critically ill patients. It is a major risk factor that results in multiple organ failure and shock. Acute kidney injury (AKI) is one of the most frequent complications underlying sepsis, which portends a heavy burden of mortality and morbidity. Thus, the present review is aimed to provide an insight into the recent progression in the molecular mechanisms targeting dysregulated immune response and cellular dysfunction involved in the development of sepsis-associated AKI, accentuating the phytoconstituents as eligible candidates for attenuating the onset and progression of sepsis-associated AKI. The pathogenesis of sepsis-mediated AKI entails a complicated mechanism and is likely to involve a distinct constellation of hemodynamic, inflammatory, and immune mechanisms. Novel biomarkers like neutrophil gelatinase-associated lipocalin, soluble triggering receptor expressed on myeloid cells 1, procalcitonin, alpha-1-microglobulin, and presepsin can help in a more sensitive diagnosis of sepsis-associated AKI. Many bioactive compounds like curcumin, resveratrol, baicalin, quercetin, and polydatin are reported to play an important role in the prevention and management of sepsis-associated AKI by decreasing serum creatinine, blood urea nitrogen, cystatin C, lipid peroxidation, oxidative stress, IL-1β, TNF-α, NF-κB, and increasing the activity of antioxidant enzymes and level of PPARγ. The plant bioactive compounds could be developed into a drug-developing candidate in managing sepsis-mediated acute kidney injury after detailed follow-up studies. Lastly, the gut-kidney axis may be a more promising therapeutic target against the onset of septic AKI, but a deeper understanding of the molecular pathways is still required.

The Influence of Heat Stress on Chicken Immune System and Mitigation of Negative Impacts by Baicalin and Baicalein

Heat stress (HS) in poultry husbandry is an important stressor and with increasing global temperatures its importance will increase. The negative effects of stress on the quality and quantity of poultry production are described in a range of research studies. However, a lack of attention is devoted to the impacts of HS on individual chicken immune cells and whole lymphoid tissue in birds. Oxidative stress and increased inflammation are accompanying processes of HS, but with deleterious effects on the whole organism. They play a key role in the inflammation and oxidative stress of the chicken immune system. There are a range of strategies that can help mitigate the adverse effects of HS in poultry. Phytochemicals are well studied and some of them report promising results to mitigate oxidative stress and inflammation, a major consequence of HS. Current studies revealed that mitigating these two main impacts of HS will be a key factor in solving the problem of increasing temperatures in poultry production. Improved function of the chicken immune system is another benefit of using phytochemicals in poultry due to the importance of poultry health management in today's post pandemic world. Based on the current literature, baicalin and baicalein have proven to have strong anti-inflammatory and antioxidative effects in mammalian and avian models. Taken together, this review is dedicated to collecting the literature about the known effects of HS on chicken immune cells and lymphoid tissue. The second part of the review is dedicated to the potential use of baicalin and baicalein in poultry to mitigate the negative impacts of HS on poultry production.

The emerging role of N6-methyladenine RNA methylation in metal ion metabolism and metal-induced carcinogenesis

N⁶-methyladenine (m⁶A) is the most common and abundant internal modification in eukaryotic mRNAs, which can regulate gene expression and perform important biological tasks. Metal ions participate in nucleotide biosynthesis and repair, signal transduction, energy generation, immune defense, and other important metabolic processes. However, long-term environmental and occupational exposure to metals through food, air, soil, water, and industry can result in toxicity, serious health problems, and cancer. Recent evidence indicates dynamic and reversible m⁶A modification modulates various metal ion metabolism, such as iron absorption, calcium uptake and transport. In turn, environmental heavy metal can alter m⁶A modification by directly affecting catalytic activity and expression level of methyltransferases and demethylases, or through reactive oxygen species, eventually disrupting normal biological function and leading to diseases. Therefore, m⁶A RNA methylation may play a bridging role in heavy metal pollution-induced carcinogenesis. This review discusses interaction among heavy metal, m⁶A, and metal ions metabolism, and their regulatory mechanism, focuses on the role of m⁶A methylation and heavy metal pollution in cancer. Finally, the role of nutritional therapy that targeting m⁶A methylation to prevent metal ion metabolism disorder-induced cancer is summarized.

The effect of Alnus incana (L.) Moench extracts in ameliorating iron overload-induced hepatotoxicity in male albino rats

Iron overload causes multiorgan dysfunction and serious damage. Alnus incana from the family Betulaceae, widely distributed in North America, is used for treating diseases. In this study, we investigated the iron chelating, antioxidant, anti-inflammatory, and antiapoptotic activities of the total and butanol extract from Alnus incana in iron-overloaded rats and identified the bioactive components in both extracts using liquid chromatography-mass spectrometry. We induced iron overload in the rats via six intramuscular injections of 12.5 mg iron dextran/100 g body weight for 30 days. The rats were then administered 60 mg ferrous sulfate /kg body weight once daily using a gastric tube. The total and butanol extracts were given orally, and the reference drug (deferoxamine) was administered subcutaneously for another month. After two months, we evaluated the biochemical, histopathological, histochemical, and immunohistochemical parameters. Iron overload significantly increased the serum iron level, liver biomarker activities, hepatic iron content, malondialdehyde, tumor necrosis factor-alpha, and caspase-3 levels. It also substantially (P < 0.05) reduced serum albumin, total protein, and total bilirubin content, and hepatic reduced glutathione levels. It caused severe histopathological alterations compared to the control rats, which were markedly (P < 0.05) ameliorated after treatment. The total extract exhibited significantly higher anti-inflammatory and antiapoptotic activities but lower antioxidant and iron-chelating activities than the butanol extract. Several polyphenolic compounds, including flavonoids and phenolic acids, were detected by ultraperformance liquid chromatography-electrospray ionization-quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS) analysis. Our findings suggest that both extracts might alleviate iron overload-induced hepatoxicity and other pathological conditions characterized by hepatic iron overload, including thalassemia and sickle-cell anemia.

Nature-Inspired Bioactive Compounds: A Promising Approach for Ferroptosis-Linked Human Diseases?

Ferroptosis is a type of cell death driven by iron overload and lipid peroxidation. It is considered a key mechanism in the development of various diseases such as atherosclerosis, Alzheimer, diabetes, cancer, and renal failure. The redox status of cells, such as the balance between intracellular oxidants (lipid peroxides, reactive oxygen species, free iron ions) and antioxidants (glutathione, glutathione Peroxidase 4), plays a major role in ferroptosis regulation and constitutes its principal biomarkers. Therefore, the induction and inhibition of ferroptosis are promising strategies for disease treatments such as cancer or neurodegenerative and cardiovascular diseases, respectively. Many drugs have been developed to exert ferroptosis-inducing and/or inhibiting reactions, such as erastin and iron-chelating compounds, respectively. In addition, many natural bioactive compounds have significantly contributed to regulating ferroptosis and ferroptosis-induced oxidative stress. Natural bioactive compounds are largely abundant in food and plants and have been for a long time, inspiring the development of various low-toxic therapeutic drugs. Currently, functional bioactive peptides are widely reported for their antioxidant properties and application in human disease treatment. The scientific evidence from biochemical and in vitro tests of these peptides strongly supports the existence of a relationship between their antioxidant properties (such as iron chelation) and ferroptosis regulation. In this review, we answer questions concerning ferroptosis milestones, its importance in physiopathology mechanisms, and its downstream regulatory mechanisms. We also address ferroptosis regulatory natural compounds as well as provide promising thoughts about bioactive peptides.

Conjugates of Tacrine and Salicylic Acid Derivatives as New Promising Multitarget Agents for Alzheimer's Disease

A series of previously synthesized conjugates of tacrine and salicylamide was extended by varying the structure of the salicylamide fragment and using salicylic aldehyde to synthesize salicylimine derivatives. The hybrids exhibited broad-spectrum biological activity. All new conjugates were potent inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) with selectivity toward BChE. The structure of the salicylamide moiety exerted little effect on anticholinesterase activity, but AChE inhibition increased with spacer elongation. The most active conjugates were salicylimine derivatives: IC₅₀ values of the lead compound 10c were 0.0826 µM (AChE) and 0.0156 µM (BChE), with weak inhibition of the off-target carboxylesterase. The hybrids were mixed-type reversible inhibitors of both cholinesterases and displayed dual binding to the catalytic and peripheral anionic sites of AChE in molecular docking, which, along with experimental results on propidium iodide displacement, suggested their potential to block AChE-induced β-amyloid aggregation. All conjugates inhibited Aβ₄₂ self-aggregation in the thioflavin test, and inhibition increased with spacer elongation. Salicylimine 10c and salicylamide 5c with (CH₂)₈ spacers were the lead compounds for inhibiting Aβ₄₂ self-aggregation, which was corroborated by molecular docking to Aβ₄₂. ABTS^•+-scavenging activity was highest for salicylamides 5a-c, intermediate for salicylimines 10a-c, low for F-containing salicylamides 7, and non-existent for methoxybenzoylamides 6 and difluoromethoxybenzoylamides 8. In the FRAP antioxidant (AO) assay, the test compounds displayed little or no activity. Quantum chemical analysis and molecular dynamics (MD) simulations with QM/MM potentials explained the AO structure-activity relationships. All conjugates were effective chelators of Cu²⁺, Fe²⁺, and Zn²⁺, with molar compound/metal (Cu²⁺) ratios of 2:1 (5b) and ~1:1 (10b). Conjugates exerted comparable or lower cytotoxicity than tacrine on mouse hepatocytes and had favorable predicted intestinal absorption and blood-brain barrier permeability. The overall results indicate that the synthesized conjugates are promising new multifunctional agents for the potential treatment of AD.

Baicalein Attenuates Brain Iron Accumulation through Protecting Aconitase 1 from Oxidative Stress in Rotenone-Induced Parkinson's Disease in Rats

Aconitase 1 (ACO1) links oxidative stress and iron accumulation in Parkinson's disease (PD). ACO1 loses its aconitase activity and turns into iron regulatory protein 1 (IRP1) upon oxidative stress. IRP1 plays an important role in the accumulation of intracellular iron. Baicalein is a flavonoid isolated from the roots of Scutellaria baicalensis. The present results show that baicalein could bind to ACO1 and protect its isoform from the oxidative stress induced by reactive oxygen species (ROS) and reactive nitrogen species (RNS). Furthermore, baicalein promoted aconitase activity and inhibited IRP1 activation in rotenone-induced PD models. Additionally, baicalein decreased the hydroxyl radicals generated by iron. In conclusion, baicalein attenuated iron accumulation and iron-induced oxidative stress in the brain of PD rats by protecting ACO1.

The Neuroprotective Potentiality of Flavonoids on Alzheimer's Disease

Alzheimer's disease (AD), due to its spread, has become a global health priority, and is characterized by senile dementia and progressive disability. The main cause of AD and other neurodegenerations (Huntington, Parkinson, Amyotrophic Lateral Sclerosis) are aggregated protein accumulation and oxidative damage. Recent research on secondary metabolites of plants such as polyphenols demonstrated that they may slow the progression of AD. The flavonoids' mechanism of action in AD involved the inhibition of acetylcholinesterase, butyrylcholinesterase, Tau protein aggregation, β-secretase, oxidative stress, inflammation, and apoptosis through modulation of signaling pathways which are implicated in cognitive and neuroprotective functions, such as ERK, PI3-kinase/Akt, NFKB, MAPKs, and endogenous antioxidant enzymatic systems. This review focuses on flavonoids and their role in AD, in terms of therapeutic potentiality for human health, antioxidant potential, and specific AD molecular targets.

Iron Chelator DIBI Suppresses Formation of Ciprofloxacin-Induced Antibiotic Resistance in Staphylococcus aureus

Antibiotic resistance of bacterial pathogens results from their exposure to antibiotics and this has become a serious growing problem that limits effective use of antibiotics. Resistance can arise from mutations induced by antibiotic-mediated damage with these mutants possessing reduced target sensitivity. We have studied ciprofloxacin (CIP)-mediated killing of Staphylococcus aureus and the influence of the Reactive Oxygen Species (ROS) inactivator, thiourea and the iron chelator DIBI, on initial killing by CIP and their effects on survival and outgrowth upon prolonged exposure to CIP. CIP at 2× MIC caused a rapid initial killing which was not influenced by initial bacterial iron status and which was followed by robust recovery growth over 96 h exposure. Thiourea and DIBI did slow the initial rate of CIP killing but the overall extent of kill by 24 h exposure was like CIP alone. Thiourea permitted recovery growth whereas this was strongly suppressed by DIBI. Small Colony Variant (SCV) survivors were progressively enriched in the survivor population during CIP exposure, and these were found to have stable slow-growth phenotype and acquired resistance to CIP and moxifloxacin but not to other non-related antibiotics. DIBI totally suppressed SCV formation with all survivors remaining sensitive to CIP and to DIBI. DIBI exposure did not promote resistance to DIBI. Our evidence indicates a high potential for DIBI as an adjunct to CIP and other antibiotics to both improve antibiotic efficacy and to thwart antibiotic resistance development.

Scutellaria baicalensis and its constituents baicalin and baicalein as antidotes or protective agents against chemical toxicities: a comprehensive review

Scutellaria baicalensis (SB), also known as the Chinese skullcap, has a long history of being used in Chinese medicine to treat a variety of conditions ranging from microbial infections to metabolic syndrome and malignancies. Numerous studies have reported that treatment with total SB extract or two main flavonoids found in its root and leaves, baicalin (BA) and baicalein (BE), can prevent or alleviate the detrimental toxic effects of exposure to various chemical compounds. It has been shown that BA and BE are generally behind the protective effects of SB against toxicants. This paper aimed to review the protective and therapeutic effects of SB and its main components BA and BE against chemical compounds that can cause intoxication after acute or chronic exposure and seriously affect different vital organs including the brain, heart, liver, and kidneys. In this review paper, we had a look into a total of 221 in vitro and in vivo studies from 1995 to 2021 from the scientific databases PubMed, Scopus, and Web of Science which reported protective or therapeutic effects of BA, BE, or SB against drugs and chemicals that one might be exposed to on a professional or accidental basis and compounds that are primarily used to simulate disease models. In conclusion, the protective effects of SB and its flavonoids can be mainly attributed to increase in antioxidants enzymes, inhibition of lipid peroxidation, reduction of inflammatory cytokines, and suppression of apoptosis pathway.

Enantioselective Response of Wheat Seedlings to Imazethapyr: From the Perspective of Fe and the Secondary Metabolite DIMBOA

The responses of trace elements and secondary metabolites to stress can reflect plant adaptation to the environment. If and how the imperative trace element Fe and the defensive secondary metabolite 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazine-3(4H)-one (DIMBOA) mediate the toxicity of chiral herbicides to nontarget plants remains inconclusive. We found that the herbicidal-active imazethapyr enantiomer [(R)-IM] stimulated heme oxygenase-1 activity, triggered the release of the catalytic product Fe²⁺, increased reactive oxygen species production, decreased the DIMBOA content, and increased the DIMBOA-Fe content. XAFS analyses and in vitro Fenton assays demonstrated that DIMBOA could relieve phytotoxicity by chelating excessive Fe³⁺ to restore Fe homeostasis. The free radical scavenging ability of the chelate of DIMBOA and Fe was also involved. This work refines the dual role of DIMBOA and Fe in mediating the enantioselective phytotoxicity of chiral herbicides, which provides a new direction for improving the herbicide resistance of crops.

Role of Iron in Aging Related Diseases

Iron progressively accumulates with age and can be further exacerbated by dietary iron intake, genetic factors, and repeated blood transfusions. While iron plays a vital role in various physiological processes within the human body, its accumulation contributes to cellular aging in several species. In its free form, iron can initiate the formation of free radicals at a cellular level and contribute to systemic disorders. This is most evident in high iron conditions such as hereditary hemochromatosis, when accumulation of iron contributes to the development of arthritis, cirrhosis, or cardiomyopathy. A growing body of research has further identified iron’s contributory effects in neurodegenerative diseases, ocular disorders, cancer, diabetes, endocrine dysfunction, and cardiovascular diseases. Reducing iron levels by repeated phlebotomy, iron chelation, and dietary restriction are the common therapeutic considerations to prevent iron toxicity. Chelators such as deferoxamine, deferiprone, and deferasirox have become the standard of care in managing iron overload conditions with other potential applications in cancer and cardiotoxicity. In certain animal models, drugs with iron chelating ability have been found to promote health and even extend lifespan. As we further explore the role of iron in the aging process, iron chelators will likely play an increasingly important role in our health.

Baicalein: promising therapeutic applications with special reference to published patents

Baicalein is a medicinally important flavonoid present in Scutellaria baicalensis, which has numerous biological benefits like anti-oxidant, anti-inflammatory, antihepatotoxicity, anticancer properties, etc. Recent studies have revealed that baicalein is an efficient antihepatoma agent and has the strongest antiproliferative effect toward cancerous bladder cell lines, and suppression of cell cycle progression in prostate cancer cells. This natural substance has a high commercial value because it strengthens the heart and cerebral vessels and protects the nervous system and also reduces diabetes and diabetic complications. In addition, baicalein is known to decrease inflammatory markers such as IL-1β, IL-6 and TNF-α. In this review, we have attempted to compile the list of recent therapeutic patents of baicalein used for treating different disorders.

Shedding a New Light on Skin Aging, Iron- and Redox-Homeostasis and Emerging Natural Antioxidants

Reactive oxygen species (ROS) are necessary for normal cell signaling and the antimicrobial defense of the skin. However excess production of ROS can disrupt the cellular redox balance and overwhelm the cellular antioxidant (AO) capacity, leading to oxidative stress. In the skin, oxidative stress plays a key role in driving both extrinsic and intrinsic aging. Sunlight exposure has also been a major contributor to extrinsic photoaging of the skin as its oxidising components disrupt both redox- and iron-homeostasis, promoting oxidative damage to skin cells and tissue constituents. Upon oxidative insults, the interplay between excess accumulation of ROS and redox-active labile iron (LI) and its detrimental consequences to the skin are often overlooked. In this review we have revisited the oxidative mechanisms underlying skin damage and aging by focussing on the concerted action of ROS and redox-active LI in the initiation and progression of intrinsic and extrinsic skin aging processes. Based on these, we propose to redefine the selection criteria for skin antiaging and photoprotective ingredients to include natural antioxidants (AOs) exhibiting robust redox-balancing and/or iron-chelating properties. This would promote the concept of natural-based or bio-inspired bifunctional anti-aging and photoprotective ingredients for skincare and sunscreen formulations with both AO and iron-chelating properties.

Synthesis and characterization of zinc derivatized 3, 5-dihydroxy 4', 7-dimethoxyflavone and its anti leishmaniasis activity against Leishmania donovani

This study reports the synthesis and characterization of zinc derivatized 3,5-dihydroxy 4', 7- dimethoxyflavone (DHDM-Zn) compound for the development of new antileishmanial agents. The interaction studies of DHDM with zinc were carried out by UV spectra and fluorescence spectra analysis. Characterization of the complex was further accomplished by multi-spectroscopic techniques such as FTIR, Raman, HRMS, NMR, FESEM-EDX. The morphological and topographical studies of synthesized DHDM-Zn were carried out using FESEM with EDX. Further, it was demonstrated that DHDM-Zn exhibited an excellent in vitro antagonistic effect against the promastigote form of L. donovani. In addition, the possible mechanisms of promastigote L. donovani cell death, by involvement of derivatized compound in arrest of the cell cycle in the G1 phase and residual cell count reduction were investigated. Promastigote growth kinetics performed in the presence of the derivatized compound revealed a slow growth rate. The combination of growth kinetics and cell cycle analysis, made it possible to interpret and classify the cause of leishmanial cell death accurately. These results support that zinc derivatized complex (DHDM-Zn) might work as a lead compound for designing and developing a new antileishmanial drug.

Antioxidant Potential and Enhancement of Bioactive Metabolite Production in In Vitro Cultures of Scutellaria lateriflora L. by Biotechnological Methods

Studies carried out using three different in vitro assays and a biological setting (Escherichia coil) demonstrated the antioxidant activity of Scutellaria lateriflora microshoot extract. Moreover, the extract exhibited no toxicity in a brine shrimp lethality bioassay. These results indicated that microshoots are a rich, safe source of antioxidants, which encouraged us to enhance their production in vitro. In agar and agitated cultures, two biotechnological strategies were applied: feeding the cultures with the biogenetic precursors of the phenolics-phenylalanine and tyrosine, and eliciting them with methyl jasmonate. Specific Scutellaria flavonoids and verbascoside were analysed by HPLC. Feeding with precursors (1 g/L) in agar cultures decreased the production of the metabolites. In agitated cultures, different concentrations of precursors (1.0-2.5 g/L) and the elicitor (10; 50; 100 µM) were tested. Additionally, parallel feeding with the precursor and elicitor in a concentration of 50 µM were applied. The best strategy for total flavonoid and verbascoside production was phenylalanine feeding (1.5 g/L), max. 3765 and 475 mg/100 g DW, respectively, after 7 days. This is the first report documenting the high antioxidant production in S. lateriflora microshoots after feeding with phenylalanine. Moreover, for the first time, bioreactor cultures were successfully maintained, obtaining attractive results (max. total flavonoid content 2348 and verbascoside 485 mg/100 g DW).

Emerging Mechanisms and Disease Implications of Ferroptosis: Potential Applications of Natural Products

Ferroptosis, a newly discovered form of regulatory cell death (RCD), has been demonstrated to be distinct from other types of RCD, such as apoptosis, necroptosis, and autophagy. Ferroptosis is characterized by iron-dependent lipid peroxidation and oxidative perturbation, and is inhibited by iron chelators and lipophilic antioxidants. This process is regulated by specific pathways and is implicated in diverse biological contexts, mainly including iron homeostasis, lipid metabolism, and glutathione metabolism. A large body of evidence suggests that ferroptosis is interrelated with various physiological and pathological processes, including tumor progression (neuro)degenerative diseases, and hepatic and renal failure. There is an urgent need for the discovery of novel effective ferroptosis-modulating compounds, even though some experimental reagents and approved clinical drugs have been well documented to have anti- or pro-ferroptotic properties. This review outlines recent advances in molecular mechanisms of the ferroptotic death process and discusses its multiple roles in diverse pathophysiological contexts. Furthermore, we summarize chemical compounds and natural products, that act as inducers or inhibitors of ferroptosis in the prevention and treatment of various diseases. Herein, it is particularly highlighted that natural products show promising prospects in ferroptosis-associated (adjuvant) therapy with unique advantages of having multiple components, multiple biotargets and slight side effects.

The Regulatory Effects and the Signaling Pathways of Natural Bioactive Compounds on Ferroptosis

Natural bioactive compounds abundantly presented in foods and medicinal plants have recently received a remarkable attention because of their various biological activities and minimal toxicity. In recent years, many natural compounds appear to offer significant effects in the regulation of ferroptosis. Ferroptosis is the forefront of international scientific research which has been exponential growth since the term was coined. This type of regulated cell death is driven by iron-dependent phospholipid peroxidation. Recent studies have shown that numerous organ injuries and pathophysiological processes of many diseases are driven by ferroptosis, such as cancer, arteriosclerosis, neurodegenerative disease, diabetes, ischemia-reperfusion injury and acute renal failure. It is reported that the initiation and inhibition of ferroptosis plays a pivotal role in lipid peroxidation, organ damage, neurodegeneration and cancer growth and progression. Recently, many natural phytochemicals extracted from edible plants have been demonstrated to be novel ferroptosis regulators and have the potential to treat ferroptosis-related diseases. This review provides an updated overview on the role of natural bioactive compounds and the potential signaling pathways in the regulation of ferroptosis.

Development and Evaluation of Thermosensitive Hydrogels with Binary Mixture of Scutellariae baicalensis radix Extract and Chitosan for Periodontal Diseases Treatment

Scutellaria baicalensis root displays anti-inflammatory and antibacterial properties due to the presence of flavonoids, particularly baicalin, baicalein, and wogonin. Our work aimed at developing thermosensitive hydrogels containing a binary mixture of S. baicalensis radix lyophilized extract and chitosan as a novel approach for periodontal diseases treatment. Two types of chitosan were employed in preliminary studies on binary mixtures with S. baicalensis radix lyophilized extract standardized for baicalin, baicalein, and wogonin. Thermosensitive hydrogels were prepared of poloxamer 407, alginate sodium, and cellulose derivatives and evaluated in terms of rheological and mucoadhesive behavior. The presence of chitosan altered the release profile of active compounds but did not affect their in vitro permeation behavior in PAMPA assay. The synergistic effects of S. baicalensis radix lyophilized extract and chitosan toward ferrous ion-chelating activity, inhibition of hyaluronidase, and pathogen growth were observed. The thermosensitive gelling system showed shear-thinning properties, gelation temperature between 25 and 27 °C, and favorable mucoadhesiveness in contact with porcine buccal mucosa, which was enhanced in the presence of binary mixture of S. baicalensis radix extract and chitosan. The release tests showed that baicalin and baicalein were liberated in a prolonged manner with a fast onset from hydrogel formulations.

Iron: an underrated factor in aging

Iron is an essential element for virtually all living organisms, but its reactivity also makes it potentially harmful. Iron accumulates with aging, and is associated with many age-related diseases; it also shortens the lifespans of several model organisms. Blocking iron absorption through drugs or natural products extends lifespan. Many life-extending interventions, such as rapamycin, calorie restriction, and old plasma dilution can be explained by the effects they have on iron absorption, excretion, and metabolism. Control of body iron stores so that they remain in a low normal range may be an important, lifespan- and healthspan-extending intervention.

Trans-Chalcone Plus Baicalein Synergistically Reduce Intracellular Amyloid Beta (Aβ42) and Protect from Aβ42 Induced Oxidative Damage in Yeast Models of Alzheimer's Disease

Finding an effective therapeutic to prevent or cure AD has been difficult due to the complexity of the brain and limited experimental models. This study utilized unmodified and genetically modified Saccharomyces cerevisiae as model organisms to find potential natural bioactive compounds capable of reducing intracellular amyloid beta 42 (Aβ₄₂) and associated oxidative damage. Eleven natural bioactive compounds including mangiferin, quercetin, rutin, resveratrol, epigallocatechin gallate (EGCG), urolithin A, oleuropein, rosmarinic acid, salvianolic acid B, baicalein and trans-chalcone were screened for their ability to reduce intracellular green fluorescent protein tagged Aβ₄₂ (GFP-Aβ₄₂) levels. The two most effective compounds from the screens were combined in varying concentrations of each to study the combined capacity to reduce GFP-Aβ₄₂. The most effective combinations were examined for their effect on growth rate, turnover of native Aβ₄₂ and reactive oxygen species (ROS). The bioactive compounds except mangiferin and urolithin A significantly reduced intracellular GFP-Aβ₄₂ levels. Baicalein and trans-chalcone were the most effective compounds among those that were screened. The combination of baicalein and trans-chalcone synergistically reduced GFP-Aβ₄₂ levels. A combination of 15 μM trans-chalcone and 8 μM baicalein was found to be the most synergistic combination. The combination of the two compounds significantly reduced ROS and Aβ₄₂ levels in yeast cells expressing native Aβ₄₂ without affecting growth of the cells. These findings suggest that the combination of baicalein and trans-chalcone could be a promising multifactorial therapeutic strategy to cure or prevent AD. However, further studies are recommended to look for similar cytoprotective activity in humans and to find an optimal dosage.

Comparison of Antioxidant Properties of a Conjugate of Taxifolin with Glyoxylic Acid and Selected Flavonoids

It is known that flavonoids can react with toxic carbonyl compounds in the process of the storage, aging, and digestion of flavonoid-rich foods and beverages. However, the effect of these reactions on the antioxidant properties of the polyphenolic fraction and the properties of the resulting products remain poorly studied. The aim of the present work was to study the antioxidant activity of quercetin, taxifolin, catechin, eriodictyol, hesperetin, naringenin and a product of the condensation of taxifolin with glyoxylic acid, as well as to reveal the structure–activity relationship of these polyphenols. It was found that flavonoids containing the catechol moiety exhibited higher antioxidant activity than hesperetin and naringenin. The product showed the highest hydrogen peroxide scavenging activity, a lower metal-reducing and a higher iron-binding ability than catechol-containing flavonoids, and a lipid peroxidation inhibitory activity comparable with that of taxifolin. Thus, the condensation of flavonoids with toxic carbonyl compounds might lead to the formation of products exhibiting high antioxidant activity. Meanwhile, the conditions under which parent flavonoids and their products exhibit the maximal antioxidant activity may differ. The data suggest that the antioxidant profile of the polyphenolic fraction and bioavailability of polyphenols, carbonyl compounds, and metal ions may change when these reactions occur.

Role of Flavonoids in the Treatment of Iron Overload

Iron overload, a high risk factor for many diseases, is seen in almost all human chronic and common diseases. Iron chelating agents are often used for treatment but, at present, most of these have a narrow scope of application, obvious side effects, and other disadvantages. Recent studies have shown that flavonoids can affect iron status, reduce iron deposition, and inhibit the lipid peroxidation process caused by iron overload. Therefore, flavonoids with iron chelating and antioxidant activities may become potential complementary therapies. In this study, we not only reviewed the research progress of iron overload and the regulation mechanism of flavonoids, but also studied the structural basis and potential mechanism of their function. In addition, the advantages and disadvantages of flavonoids as plant iron chelating agents are discussed to provide a foundation for the prevention and treatment of iron homeostasis disorders using flavonoids.

Inhibition of Oxidative Stress and ALOX12 and NF-κB Pathways Contribute to the Protective Effect of Baicalein on Carbon Tetrachloride-Induced Acute Liver Injury

This study investigates the protective effect of baicalein on carbon tetrachloride (CCl₄)-induced acute liver injury and the underlying molecular mechanisms. Mice were orally administrated baicalein at 25 and 100 mg/kg/day for 7 consecutive days or ferrostatin-1 (Fer-1) at 10 mg/kg was i.p. injected in mice at 2 and 24 h prior to CCl₄ injection or the vehicle. Our results showed that baicalein or Fer-1 supplementation significantly attenuated CCl₄ exposure-induced elevations of serum alanine aminotransferase and aspartate aminotransferase, and malondialdehyde levels in the liver tissues and unregulated glutathione levels. Baicalein treatment inhibited the nuclear factor kappa-B (NF-κB) pathway, activated the erythroid 2-related factor 2 (Nrf2)/heme oxygenase 1 (HO-1) pathway in liver tissues, and markedly improved CCl₄-induced apoptosis, inflammation and ferroptosis in liver tissues exposed with CCl₄. In vitro, baicalein treatment improved CCl₄ -induced decreases of cell viabilities and knockdown of Nrf2 and arachidonate 12-lipoxygenase (ALOX12) genes partly abolished the protective effect of baicalein on CCl₄ -induced cytotoxicity in HepG2 cells. In conclusion, our results reveal that baicalein supplementation ameliorates CCl₄-induced acute liver injury in mice by upregulating the antioxidant defense pathways and downregulating oxidative stress, apoptosis, inflammation and ferroptosis, which involved the activation of Nrf2 pathway and the inhibition of ALOX12 and NF-κB pathways.

Skin Antiaging Effects of the Fermented Outer Layers of Leaf Skin of Aloe barbadensis Miller Associated with the Enhancement of Mitochondrial Activities of UVb-Irradiated Human Skin Fibroblasts

This study is the first to show that increased mitochondrial activities improved the antiaging effects of Aloe vera leaf skin fermented by Lactobacillus plantarum on UVb-irradiated skin fibroblasts. The fermented extract (AF) increased the activities of mitochondrial reductase and the complex II and significantly reduced reactive oxygen species (ROS) production, even under UVb stress conditions, and also increased DPPH free radical scavenging activities compared with the hot water extract of outer layers of aloe leaf (AW) and quercetin itself. AF exerted a synergistic effect with quercetin and bioactive substances derived from the fermentation process. Moreover, mitochondrial activation of UVb-irradiated human skin fibroblasts by 0.3% (w/v) of the AF plays important roles in increasing collagen production up to 125 ± 5.45% and decreasing MMP-1 secretion down to 69.41 ± 2.63% of the control levels. The AF enhanced the upregulation of collagen gene expression, and this change was also greater than those induced by the AW and quercetin. Therefore, this study concludes that fermentation of the skin of aloe leaves increases the activation of mitochondria and inhibits the photo-aging of UVb-irradiated skin fibroblasts.

Protective effect of baicalein on DNA oxidative damage and its binding mechanism with DNA: An in vitro and molecular docking study

In this work, the protective effect of baicalein on DNA oxidative damage and its possible protection mechanisms were investigated. 2-thiobarbituric acid (TBA) colorimetry and agarose gel electrophoresis study found that baicalein protected the deoxyribose residue and double-stranded backbone of DNA from the damage of hydroxyl radicals. Antioxidant analysis results showed that baicalein has excellent radicals scavenging effects and Fe²⁺ chelating ability, which might be the mechanism of baicalein protecting DNA. DNA binding studies indicated that baicalein bound to the minor groove of DNA with moderate binding affinity (K = (7.35 ± 0.91) × 10³ M^-1). Hydrogen bonding and van der Waals forces played a major role in driving the binding process. Molecular docking further confirmed the experimental results. This binding could stabilize DNA double helix structure, thereby protecting DNA from oxidative damage. This study may provide theoretical basis for designing new functional foods of baicalein for DNA damage protection.

Prospective Role of Polyphenolic Compounds in the Treatment of Neurodegenerative Diseases

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Aging is an important stage of the human life cycle and the primary risk factor for neurodegenerative diseases (ND). The aging process contributes to modifications in cells, which may lead to a lack of nutrient signaling, disrupted cellular activity, increased oxidative pressure, cell homeostasis depletion, genomic instability, misfolded protein aggregation, impaired cellular protection, and telomere reduction. The neuropathologies found in Alzheimer's disease (AD) and Parkinson's disease (PD) are internally and extrinsically compound environmental stressors which may be partially alleviated by using different phytochemicals. The new therapies for ND are restricted as they are primarily targeted at final disease progression, including behavioral shifts, neurological disorders, proteinopathies, and neuronal failure. This review presents the role of phytochemicals-related polyphenolic compounds as an accompanying therapy model to avoid neuropathologies linked to AD, PD and to simultaneously enhance two stochastic stressors, namely inflammation and oxidative stress, promoting their disease pathologies. Therefore, this approach represents a prophylactic way to target risk factors that rely on their action against ND that does not occur through current pharmacological agents over the life of a person.

Natural Antioxidants in Anemia Treatment

Anemia, characterized by a decrease of the hemoglobin level in the blood and a reduction in carrying capacity of oxygen, is a major public health problem which affects people of all ages. The methods used to treat anemia are blood transfusion and oral administration of iron-based supplements, but these treatments are associated with a number of side effects, such as nausea, vomiting, constipation, and stomach pain, which limit its long-term use. In addition, oral iron supplements are poorly absorbed in the intestinal tract, due to overexpression of hepcidin, a peptide hormone that plays a central role in iron homeostasis. In this review, we conducted an analysis of the literature on biologically active compounds and plant extracts used in the treatment of various types of anemia. The purpose of this review is to provide up-to-date information on the use of these compounds and plant extracts, in order to explore their therapeutic potential. The advantage of using them is that they are available from natural resources and can be used as main, alternative, or adjuvant therapies in many diseases, such as various types of anemia.