Toxicological evaluation of a flavonoid, chrysin: morphological, behavioral, biochemical and histopathological assessments in rats

Integrated bioinformatics and multiomics reveal Liupao tea extract alleviating NAFLD via regulating hepatic lipid metabolism and gut microbiota

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) poses a significant global public health concern. Liupao tea (LPT) is a Chinese national geographical indication product renowned for its lipid-lowering properties. However, the precise mechanisms and active constituents contributing to the efficacy of LPT against NAFLD remain unclear.

PURPOSE

This study aims to comprehensively explore the therapeutic potential of Liupao tea extract (LPTE) in alleviating NAFLD through an integrated strategy.

METHODS

Initially, network pharmacology analysis was conducted based on LPTE chemical ingredient analysis, identifying core targets and key components. Potential active ingredients were validated through chemical standards based on LC-MS/MS. To confirm the pharmacological efficacy of LPTE in NAFLD, NAFLD mice models were employed. Alterations in hepatic lipid metabolism were comprehensively elucidated through integration of metabolomics, lipidomics, network pharmacology analysis, and real-time PCR analysis. To further explore the binding interactions between key components and core targets, molecular docking and microscale thermophoresis (MST) analysis were employed. Furthermore, to investigate LPTE administration effectiveness on gut microbiota in NAFLD mice, a comprehensive approach was employed. This included Metorigin analysis, 16S rRNA sequencing, molecular docking, and fecal microbiome transplantation (FMT).

RESULTS

Study identified naringenin, quercetin, luteolin, and kaempferol as the potential active ingredients of LPTE. These compounds exhibited therapeutic potential for NAFLD by targeting key proteins such as PTGS2, CYP3A4, and ACHE, which are involved in the metabolic pathways of hepatic linoleic acid (LA) and glycerophospholipid (GP) metabolism. The therapeutic effectiveness of LPTE was observed to be comparable to that of simvastatin. Furthermore, LPTE exhibited notable efficacy in alleviating NAFLD by influencing alterations in gut microbiota composition (Proteobacteria phylum, Lactobacillus and Dubosiella genus) that perhaps impact LA and GP metabolic pathways.

CONCLUSION

LPTE could be effective in preventing high-fat diet (HFD)-induced NAFLD by modulating hepatic lipid metabolism and gut microbiota. This study firstly integrated bioinformatics and multi-omics technologies to identify the potential active components and key microbiota associated with LPTE's effects, while also primally elucidating the action mechanisms of LPTE in alleviating NAFLD. The findings offer a conceptual basis for LPTE's potential transformation into an innovative pharmaceutical agent for NAFLD prevention.

Multi-Endpoint Toxicological Assessment of Chrysin Loaded Oil-in-Water Emulsion System in Different Biological Models

Chrysin is hypothesized to possess the ability to prevent different illnesses, such as diabetes, cancer, and neurodegenerative disorders. Nonetheless, chrysin has a low solubility under physiological conditions, resulting in limited bioavailability. In a previous study, we utilized an oil-in-water emulsion system (chrysin-ES or chrysin-NE) to encapsulate chrysin, thereby increasing its bioaccessibility and preserving its antioxidant and anti-Alzheimer's properties. To promote the chrysin-ES as a supplementary and functional food, it was obligatory to carry out a safety assessment. Cytotoxicity testing showed that chrysin-ES was harmless, with no killing effect on 3T3-L1 (adipocytes), RAW 264.7 (macrophages), HEK293 (kidney cells), and LX-2 (hepatic stellate cells). The acute toxicity evaluation demonstrated that the 50% lethal dose (LD50) for chrysin-ES was greater than 2000 mg/kg BW. Genotoxicity assessments found that chrysin-ES did not induce DNA mutations in vitro or in vivo. Furthermore, chrysin and chrysin-ES exhibited anti-mutagenic properties against PhIP-induced and IQ-induced mutagenesis in the Ames test, while they inhibited urethane-, ethyl methanesulfonate-, mitomycin C-, and N-nitrosomethylurea-mediated mutations in Drosophila. The present study illustrates the safety and anti-genotoxicity properties of chrysin-ES, allowing for the further development of chrysin-based food supplements and nutraceuticals.

Chrysin inhibits ferroptosis of cerebral ischemia/reperfusion injury via regulating HIF-1α/CP loop

Chrysin is a natural flavonoid with powerful neuroprotective capacity. Cerebral ischemia/reperfusion injury (CIRI) is associated with oxidative stress and ferroptosis. Hypoxia-inducible factor 1α (HIF-1α) and ceruloplasmin (CP) are the critical targets for oxidation reactions and iron transport. But the regulatory mechanism between them is still unclear. Transient middle cerebral artery occlusion (tMCAO) model in rats and oxygen and glucose deprivation/re-oxygenation (OGD/R) model in PC12 cells were applied. Pathological tissue staining and biochemical kit were used to evaluate the effect of chrysin. The relationship between HIF-1α and CP was verified by transcriptomics, qRT-PCR and Western blot. In CIRI, HIF-1α/CP loop was discovered to be the regulatory pathway of ferroptosis. CIRI led to activation and nuclear translocation of HIF-1α, which promoted CP transcription and translation, and downstream ferroptosis. Inhibition of HIF-1α had opposite effect on CP and ferroptosis regulation. Overexpression of CP increased the expression of HIF-1α, nevertheless, inhibited the nuclear translocation of HIF-1α and alleviated CIRI. Silencing CP promoted HIF-1α elevation in nucleus and aggravated CIRI. Mechanistically, chrysin restrained HIF-1α nuclear translocation, thereby inhibiting CP transcription and translation, which in turn reduced downstream HIF-1α expression and mitigated ferroptosis in CIRI. Our results highlight chrysin restrains ferroptosis in CIRI through HIF-1α/CP loop.

Development of dietary small molecules as multi-targeting treatment strategies for Alzheimer's disease

Cognitive dysfunction can occur both in normal aging and age-related neurological disorders, such as mild cognitive impairment and Alzheimer's disease (AD). These disorders have few treatment options due to side effects and limited efficacy. New approaches to slow cognitive decline are urgently needed. Dietary interventions (nutraceuticals) have received considerable attention because they exhibit strong neuroprotective properties and may help prevent or minimize AD symptoms. Biological aging is driven by a series of interrelated mechanisms, including oxidative stress, neuroinflammation, neuronal apoptosis, and autophagy, which function through various signaling pathways. Recent clinical and preclinical studies have shown that dietary small molecules derived from natural sources, including flavonoids, carotenoids, and polyphenolic acids, can modulate oxidative damage, cognitive impairments, mitochondrial dysfunction, neuroinflammation, neuronal apoptosis, autophagy dysregulation, and gut microbiota dysbiosis. This paper reviews research on different dietary small molecules and their bioactive constituents in the treatment of AD. Additionally, the chemical structure, effective dose, and specific molecular mechanisms of action are comprehensively explored. This paper also discusses the advantages of using nanotechnology-based drug delivery, which significantly enhances oral bioavailability, safety, and therapeutic effect, and lowers the risk of adverse effects. These agents have considerable potential as novel and safe therapeutic agents that can prevent and combat age-related AD.

Telomerase: a nexus between cancer nanotherapy and circadian rhythm

Cancer represents a complex disease category defined by the unregulated proliferation and dissemination of anomalous cells within the human body. According to the GLOBOCAN 2020 report, the year 2020 witnessed the diagnosis of approximately 19.3 million new cases of cancer and 10.0 million individuals succumbed to the disease. A typical cell eventually becomes cancerous because of a long-term buildup of genetic instability and replicative immortality. Telomerase is a crucial regulator of cancer progression as it induces replicative immortality. In cancer cells, telomerase inhibits apoptosis by elongating the length of the telomeric region, which usually protects the genome from shortening. Many nanoparticles are documented as being available for detecting the presence of telomerase, and many were used as delivery systems to transport drugs. Furthermore, telomere homeostasis is regulated by the circadian time-keeping machinery, leading to 24-hour rhythms in telomerase activity and TERT mRNA expression in mammals. This review provides a comprehensive discussion of various kinds of nanoparticles used in telomerase detection, inhibition, and multiple drug-related pathways, as well as enlightens an imperative association between circadian rhythm and telomerase activity from the perspective of nanoparticle-based anticancer therapeutics.

Roles of flavonoids in ischemic heart disease: Cardioprotective effects and mechanisms against myocardial ischemia and reperfusion injury

BACKGROUND

Flavonoids are extensively present in fruits, vegetables, grains, and medicinal plants. Myocardial ischemia and reperfusion (MI/R) comprise a sequence of detrimental incidents following myocardial ischemia. Research indicates that flavonoids have the potential to act as cardioprotective agents against MI/R injuries. Several specific flavonoids, e.g., luteolin, hesperidin, quercetin, kaempferol, and puerarin, have demonstrated cardioprotective activities in animal models.

PURPOSE

The objective of this review is to identify the cardioprotective flavonoids, investigate their mechanisms of action, and explore their application in myocardial ischemia.

METHODS

A search of PubMed database and Google Scholar was conducted using keywords "myocardial ischemia" and "flavonoids". Studies published within the last 10 years reporting on the cardioprotective effects of natural flavonoids on animal models were analyzed.

RESULTS

A total of 55 natural flavonoids were identified and discussed within this review. It can be summarized that flavonoids regulate the following main strategies: antioxidation, anti-inflammation, calcium modulation, mitochondrial protection, ER stress inhibition, anti-apoptosis, ferroptosis inhibition, autophagy modulation, and inhibition of adverse cardiac remodeling. Additionally, the number and position of OH, 3'4'-catechol, C2=C3, and C4=O may play a significant role in the cardioprotective activity of flavonoids.

CONCLUSION

This review serves as a reference for designing a daily diet to prevent or reduce damages following ischemia and screening of flavonoids for clinical application.

Bitter Phytochemicals as Novel Candidates for Skin Disease Treatment

Skin diseases represent a global healthcare challenge due to their rising incidence and substantial socio-economic burden. While biological, immunological, and targeted therapies have brought a revolution in improving quality of life and survival rates for certain dermatological conditions, there remains a stringent demand for new remedies. Nature has long served as an inspiration for drug development. Recent studies have identified bitter taste receptors (TAS2Rs) in both skin cell lines and human skin. Additionally, bitter natural compounds have shown promising benefits in addressing skin aging, wound healing, inflammatory skin conditions, and even skin cancer. Thus, TAS2Rs may represent a promising target in all these processes. In this review, we summarize evidence supporting the presence of TAS2Rs in the skin and emphasize their potential as drug targets for addressing skin aging, wound healing, inflammatory skin conditions, and skin carcinogenesis. To our knowledge, this is a pioneering work in connecting information on TAS2Rs expression in skin and skin cells with the impact of bitter phytochemicals on various beneficial effects related to skin disorders.

Secondary Metabolites Isolated from Artemisia afra and Artemisia annua and Their Anti-Malarial, Anti-Inflammatory and Immunomodulating Properties-Pharmacokinetics and Pharmacodynamics: A Review

There are over 500 species of the genus Artemisia in the Asteraceae family distributed over the globe, with varying potentials to treat different ailments. Following the isolation of artemisinin (a potent anti-malarial compound with a sesquiterpene backbone) from Artemisia annua, the phytochemical composition of this species has been of interest over recent decades. Additionally, the number of phytochemical investigations of other species, including those of Artemisia afra in a search for new molecules with pharmacological potentials, has increased in recent years. This has led to the isolation of several compounds from both species, including a majority of monoterpenes, sesquiterpenes, and polyphenols with varying pharmacological activities. This review aims to discuss the most important compounds present in both plant species with anti-malarial properties, anti-inflammatory potentials, and immunomodulating properties, with an emphasis on their pharmacokinetics and pharmacodynamics properties. Additionally, the toxicity of both plants and their anti-malaria properties, including those of other species in the genus Artemisia, is discussed. As such, data were collected via a thorough literature search in web databases, such as ResearchGate, ScienceDirect, Google scholar, PubMed, Phytochemical and Ethnobotanical databases, up to 2022. A distinction was made between compounds involved in a direct anti-plasmodial activity and those expressing anti-inflammatory and immunomodulating activities or anti-fever properties. For pharmacokinetics activities, a distinction was made between compounds influencing bioavailability (CYP effect or P-Glycoprotein effect) and those affecting the stability of pharmacodynamic active components.

Chrysin protects against cerebral ischemia-reperfusion injury in hippocampus via restraining oxidative stress and transition elements

Chrysin is a natural flavonoid compound that has antioxidant and neuroprotective effects. Cerebral ischemia reperfusion (CIR) is closely connected with increased oxidative stress in the hippocampal CA1 region and homeostasis disorder of transition elements such as iron (Fe), copper (Cu) and zinc (Zn). This exploration was conducted to elucidate the antioxidant and neuroprotective effects of chrysin based on transient middle cerebral artery occlusion (tMCAO) in rats. Experimentally, sham group, model group, chrysin (50.0 mg/kg) group, Ginaton (21.6 mg/kg) group, Dimethyloxallyl Glycine (DMOG, 20.0 mg/kg) + chrysin group and DMOG group were devised. The rats in each group were performed to behavioral evaluation, histological staining, biochemical kit detection, and molecular biological detection. The results indicated that chrysin restrained oxidative stress and the rise of transition element levels, and regulated transition element transporter levels in tMCAO rats. DMOG activated hypoxia-inducible factor-1 subunit alpha (HIF-1α), reversed the antioxidant and neuroprotective effects of chrysin, and increased transition element levels. In a word, our findings emphasize that chrysin plays a critical role in protecting CIR injury via inhibiting HIF-1α against enhancive oxidative stress and raised transition metal levels.

Chrysin: A polyedric flavone as a tool to explore new phytotherapeutic applications and drug design

In the field of pharmaceutical research, a branch that has become more and more interesting is phytochemistry. Among phytochemicals, flavonoids have been studied a lot over the past 30 years. This review summarizes the chemical characteristics, metabolism, applications, and toxicity of a particular flavonoid, chrysin, recorded in the last 10 years and supported by solid biological assays. Furthermore, this review highlights some derivatives of chrysin investigated to obtain more bioavailable molecules that maintain or improve chrysin's bioactivities, enclosing a chrysin patent section, as well.

Phytochemicals as potential target on thioredoxin-interacting protein (TXNIP) for the treatment of cardiovascular diseases

Cardiovascular diseases (CVDs) are currently the major cause of death and morbidity on a global scale. Thioredoxin-interacting protein (TXNIP) is a marker related to metabolism, oxidation, and inflammation induced in CVDs. The overexpression of TXNIP is closely related to the occurrence and development of CVDs. Hence, TXNIP inhibition is critical for reducing the overactivation of its downstream signaling pathway and, as a result, myocardial cell damage. Due to the chemical variety of dietary phytochemicals, they have garnered increased interest for CVDs prevention and therapy. Phytochemicals are a source of medicinal compounds for a variety of conditions, which aids in the development of effective and safe TXNIP-targeting medications. The objective of this article is to find and virtual screen novel safe, effective, and economically viable TXNIP inhibitors from flavonoids, phenols, and alkaloids derived from foods and plants. The results of the docking study revealed that silibinin, rutin, luteolin, baicalin, procyanidin B2, hesperetin, icariin, and tilianin in flavonoids, polydatin, resveratrol, and salidroside in phenols, and neferine in alkaloids had the highest Vina scores, indicating that these compounds are the active chemicals on TXNIP. In particular, silibinin can be utilized as a lead chemical in the process of structural alteration. These dietary phytochemicals may aid in the discovery of lead compounds for the development of innovative TXNIP agents for the treatment of cardiovascular disease.

Flavonoids and saponins: What have we got or missed?

BACKGROUND

Flavonoids and saponins are important bioactive compounds that have attracted wide research interests. This review aims to summarise the state of the art of the pharmacology, toxicology and clinical efficacy of these compounds.

METHODS

Data were retrieved from PubMed, Cochrane Library, Web of Science, Proquest, CNKI, Chongqing VIP, Wanfang, NPASS and HIT 2.0 databases. Meta-analysis and systematic reviews were evaluated following the PRISMA guideline. Statistical analyses were conducted using SPSS23.0.

RESULTS

Rising research trends on flavonoids and saponins were observed since the 1990s and the 2000s, respectively. Studies on pharmacological targets and activities of flavonoids and saponins represent an important area of research advances over the past decade, and these important resources have been documented in open-access specialised databases and can be retrieved with ease. The rising research on flavonoids and saponins can be attributed, at least in part, to their links with some highly investigated fields of research, e.g., oxidative stress, inflammation and cancer; i.e., 6.88% and 3.03% of publications on oxidative stress cited by PubMed in 1990 - 2021 involved flavonoids and saponins, respectively, significantly higher than the percentage involving alkaloids (1.88%). The effects of flavonoids concern chronic venous insufficiency, cervical lesions, diabetes, rhinitis, dermatopathy, prostatitis, menopausal symptoms, angina pectoris, male pattern hair loss, lymphocytic leukaemia, gastrointestinal diseases and traumatic cerebral infarction, etc, while those of saponins may have impact on venous oedema in chronic deep vein incompetence, erectile dysfunction, acute impact injuries and systemic lupus erythematosus, etc. The volume of in vitro research appears way higher than in vivo and clinical studies, with only 10 meta-analyses and systematic reviews (involving 290 interventional and observational studies), and 36 clinical studies on flavonoids and saponins. Data are sorely needed on pharmacokinetics, in vitro pan-assay interferences, purity of tested compounds, interactions in complex herbal extracts, real impact of anti-oxidative strategies, and mid- and long-term toxicities. To fill these important gaps, further investigations are warranted. On the other hand, drug interactions may cause adverse effects but might also be useful for synergism, with the goals of enhancing effects or of detoxifying. Furthermore, the interactions between phytochemicals and the intestinal microbiota are worth investigating as the field may present a promising potential for novel drug development.

Therapeutic Potential of Controlled Delivery Systems in Asthma: Preclinical Development of Flavonoid-Based Treatments

Asthma is a chronic disease with increasing prevalence and incidence, manifested by allergic inflammatory reactions, and is life-threatening for patients with severe disease. Repetitive challenges with the allergens and limitation of treatment efficacy greatly dampens successful management of asthma. The adverse events related to several drugs currently used, such as corticosteroids and β-agonists, and the low rigorous adherence to preconized protocols likely compromises a more assertive therapy. Flavonoids represent a class of natural compounds with extraordinary antioxidant and anti-inflammatory properties, with their potential benefits already demonstrated for several diseases, including asthma. Advanced technology has been used in the pharmaceutical field to improve the efficacy and safety of drugs. Notably, there is also an increasing interest for the application of these techniques using natural products as active molecules. Flavones, flavonols, flavanones, and chalcones are examples of flavonoid compounds that were tested in controlled delivery systems for asthma treatment, and which achieved better treatment results in comparison to their free forms. This review aims to provide a comprehensive understanding of the development of novel controlled delivery systems to enhance the therapeutic potential of flavonoids as active molecules for asthma treatment.

Flavonoids a Bioactive Compound from Medicinal Plants and Its Therapeutic Applications

Plants generally secrete secondary metabolites in response to stress. These secondary metabolites are very useful for humankind as they possess a wide range of therapeutic activities. Secondary metabolites produced by plants include alkaloids, flavonoids, terpenoids, and steroids. Flavonoids are one of the classes of secondary metabolites of plants found mainly in edible plant parts such as fruits, vegetables, stems, grains, and bark. They are synthesized by the phenylpropanoid pathway. Flavonoids possess antibacterial, antiviral, antioxidant, anti-inflammatory, antimutagenic, and anticarcinogenic properties. Due to their various therapeutic applications, various pharmaceutical companies have exploited different plants for the production of flavonoids. To overcome this situation, various biotechnological strategies have been incorporated to improve the production of different types of flavonoids. In this review, we have highlighted the various types of flavonoids, their biosynthesis, properties, and different strategies to enhance the production of flavonoids.

Neuroprotective Potential of Chrysin: Mechanistic Insights and Therapeutic Potential for Neurological Disorders

Chrysin, a herbal bioactive molecule, exerts a plethora of pharmacological effects, including anti-oxidant, anti-inflammatory, neuroprotective, and anti-cancer. A growing body of evidence has highlighted the emerging role of chrysin in a variety of neurological disorders, including Alzheimer’s and Parkinson’s disease, epilepsy, multiple sclerosis, ischemic stroke, traumatic brain injury, and brain tumors. Based on the results of recent pre-clinical studies and evidence from studies in humans, this review is focused on the molecular mechanisms underlying the neuroprotective effects of chrysin in different neurological diseases. In addition, the potential challenges, and opportunities of chrysin’s inclusion in the neurotherapeutics repertoire are critically discussed.

Chrysin alleviates alteration of bone-remodeling markers in ovariectomized rats and exhibits estrogen-like activity in silico

BACKGROUND

Evidences are beginning to accrue that flavonoids, particularly phytoestrogens, could have beneficial effects against several age-related diseases linked to estrogen deficiency including postmenopausal osteoporosis.

METHODS

In this study, the effect of chrysin on selected bone-remodeling markers in ovariectomized rats and its estrogen-like activity in silico were investigated.

RESULTS

The data indicated that administration of chrysin at 50 mg/kg and 100 mg/kg for 6 weeks to OVX rats significantly (p < 0.05) prevented body weight gain and partially reverse uterine weight loss. In addition, treatment of OVX rats significantly (p < 0.01) increased femur dry weight, femur ash weight, bone ash calcium, and phosphorous levels in a dose-dependent manner. However, there was significant (p < 0.001) decline in serum estradiol level in all OVX rats compared to the sham-operated group. Interestingly, administration of chrysin significantly (p < 0.05) reversed the reduction of estradiol induced by ovariectomy compared to untreated OVX rats. Moreover, administration of chrysin to OVX rats significantly (p < 0.05) suppressed excessive elevation of bone-remodeling markers expression compared to untreated OVX rats. Similarly, molecular docking analysis revealed that chrysin interacts with both α and β estrogen receptors with exothermic binding energies of -229.83 kcal/Mol and -252.72 kcal/Mol, respectively, and also fits perfectly into the active site of both α and β estrogen receptors.

CONCLUSION

This study demonstrated that chrysin exhibits potential antiosteoporotic effects against bone loss in OVX rats through enhanced bone mineral contents and preventing excessive elevation of bone-remodeling markers and bone-resorbing cytokine.

Flavonoids are promising safe therapy against COVID-19

Flavonoids are a class of phenolic natural products, well-identified in traditional and modern medicines in the treatment of several diseases including viral infection. Flavonoids showed potential inhibitory activity against coronaviruses including the current pandemic outbreak caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and designated as COVID-19. Here, we have collected all data related to the potential inhibitory mechanisms of flavonoids against SARS-CoV-2 infection and their significant immunomodulatory activities. The data were mapped and compared to elect major flavonoids with a promising role in the current pandemic. Further, we have linked the global existence of flavonoids in medicinal plants and their role in protection against COVID-19. Computational analysis predicted that flavonoids can exhibit potential inhibitory activity against SARS-CoV-2 by binding to essential viral targets required in virus entry and/ or replication. Flavonoids also showed excellent immunomodulatory and anti-inflammatory activities including the inhibition of various inflammatory cytokines. Further, flavonoids showed significant ability to reduce the exacerbation of COVID-19 in the case of obesity via promoting lipids metabolism. Moreover, flavonoids exhibit a high safety profile, suitable bioavailability, and no significant adverse effects. For instance, plants rich in flavonoids are globally distributed and can offer great protection from COVID-19. The data described in this study strongly highlighted that flavonoids particularly quercetin and luteolin can exhibit promising multi-target activity against SARS-CoV-2, which promote their use in the current and expected future outbreaks. Therefore, a regimen of flavonoid-rich plants can be recommended to supplement a sufficient amount of flavonoids for the protection and treatment from SARS-CoV-2 infection.