Chrysin suppressed inflammatory responses and the inducible nitric oxide synthase pathway after spinal cord injury in rats

Self-Nanoemulsion Intrigues the Gold Phytopharmaceutical Chrysin: In Vitro Assessment and Intrinsic Analgesic Effect

Chrysin is a natural flavonoid with a wide range of bioactivities. Only a few investigations have assessed the analgesic activity of chrysin. The lipophilicity of chrysin reduces its aqueous solubility and bioavailability. Hence, self-nanoemulsifying drug delivery systems (SNEDDS) were designed to overcome this problem. Kollisolv GTA, Tween 80, and Transcutol HP were selected as oil, surfactant, and cosurfactant, respectively. SNEDDS A, B, and C were prepared, loaded with chrysin (0.1%w/w), and extensively evaluated. The optimized formula (B) encompasses 25% Kollisolv GTA, 18.75% Tween 80, and 56.25% Transcutol HP was further assessed. TEM, in vitro release, and biocompatibility towards the normal oral epithelial cell line (OEC) were estimated. Brain targeting and acetic acid-induced writhing in a mouse model were studied. After testing several adsorbents, powdered SNEDDS B was formulated and evaluated. The surfactant/cosurfactant (S/CoS) ratio of 1:3 w/w was appropriate for the preparation of SNEDDS. Formula B exhibited instant self-emulsification, spherical nanoscaled droplets of 155.4 ± 32.02 nm, and a zeta potential of - 12.5 ± 3.40 mV. The in vitro release proved the superiority of formula B over chrysin suspension (56.16 ± 10.23 and 9.26 ± 1.67%, respectively). The biocompatibility of formula B towards OEC was duplicated (5.69 ± 0.03 µg/mL). The nociceptive pain was mitigated by formula B more efficiently than chrysin suspension as the writhing numbers reduced from 8.33 ± 0.96 to 0 after 60 min of oral administration. Aerosil R972 was selected as an adsorbent, and its chemical compatibility was confirmed. In conclusion, our findings prove the therapeutic efficacy of chrysin self-nanoemulsion as a potential targeting platform to combat pain.

An outlook on the target-based molecular mechanism of phytoconstituents as immunomodulators

The immune system is one of the essential defense mechanisms. Immune system inadequacy increases the risk of infections and cancer diseases, whereas over-activation of the immune system causes allergies or autoimmune disorders. Immunomodulators have been used in the treatment of immune-related diseases. There is growing interest in using herbal medicines as multicomponent agents to modulate the complex immune system in immune-related diseases. Many therapeutic phytochemicals showed immunomodulatory effects by various mechanisms. This mechanism includes stimulation of lymphoid cell, phagocytosis, macrophage, and cellular immune function enhancement. In addition increased antigen-specific immunoglobulin production, total white cell count, and inhibition of TNF-α, IFN-γ, NF-kB, IL-2, IL-6, IL-1β, and other cytokines that influenced the immune system. This review aims to overview, widely investigated plant-derived phytoconstituents by targeting cells to modulate cellular and humoral immunity in in vivo and in vitro. However, further high-quality research is needed to confirm the clinical efficacy of plant-based immunomodulators.

Oxidative stress following spinal cord injury: From molecular mechanisms to therapeutic targets

Spinal cord injury (SCI) is a medical condition that results from severe trauma to the central nervous system; it imposes great psychological and economic burdens on affected patients and their families. The dynamic balance between reactive oxygen species (ROS) and antioxidants is essential for maintaining normal cellular physiological functions. As important intracellular signaling molecules, ROS regulate numerous physiological activities, including vascular reactivity and neuronal function. However, excessive ROS can cause damage to cellular macromolecules, including DNA, lipids, and proteins; this damage eventually leads to cell death. This review discusses the mechanisms of oxidative stress in SCI and describes some signaling pathways that regulate oxidative injury after injury, with the aim of providing guidance for the development of novel SCI treatment strategies.

Uro-protective role of chrysin against cyclophosphamide-induced hemorrhagic cystitis in rats involving the turning-off NF-κB/P38-MAPK, NO/PARP-1 and STAT-3 signaling cascades

BACKGROUND

Chemotherapeutic agents are used to treat a wide range of cancer types, but they cause serious side effects which must be managed after treatment. Cyclophosphamide (CYP) is one of chemotherapeutic drugs that causes hemorrhagic cystitis (HC) induced by acrolein.

OBJECTIVE

The current investigation intended to uncover the role of chrysin (CHR) in CYP-induced HC in rats and explore the signaling pathway beyond this effect.

ANALYSIS

process: A single dose of CYP (200 mg/kg/IP) was injected, meanwhile CHR (25, 50 and 100 mg/kg, P.O) was administered respectively for 7 days prior to CYP administration and resume for 7 days afterwards. Urinary bladder tissue was then isolated from all rats to assess oxidative stress and inflammatory biomarkers. Moreover, histopathological examinations were performed.

RESULTS

Treatment with CHR showed a marked alleviation in oxidative stress biomarkers induced by CYP. Furthermore, CHR treatment presented a dose-dependent boost in the anti-inflammatory; IL-10 levels and a drop in the pro-inflammatory biomarkers; IL-1β, IL-6, and TNF-α. Additionally, stabilization of the PARP-1 protein expression was also detected thus preventing DNA damage. Similarly, CHR restored the urinary bladder cGMP levels. Notably, CHR treatment was accompanied with inhibition in NF-κB/p38-MAPK, NO/PARP-1 and STAT-3 signaling pathways inflammatory cascades. All these findings conformed with the histopathological examinations as well as iNOS immunostaining in the urinary bladder tissue.

CONCLUSION

Co-administration of CHR and CYP attained uro-protective therapeutic potential to guard against HC as well as spot the tangled mechanism of CHR in attenuating the HC induced by CYP.

Chrysin Is Immunomodulatory and Anti-Inflammatory against Complete Freund's Adjuvant-Induced Arthritis in a Pre-Clinical Rodent Model

Chrysin (5,7-dihydroxyflavone) has many pharmacological properties including anti-inflammatory actions. The objective of this study was to evaluate the anti-arthritic activity of chrysin and to compare its effect with the non-steroidal anti-inflammatory agent, piroxicam, against complete Freund's adjuvant (CFA)-induced arthritis in a pre-clinical model in rats. Rheumatoid arthritis was induced by injecting CFA intra-dermally in the sub-plantar region of the left hind paw of rats. Chrysin (50 and 100 mg/kg) and piroxicam (10 mg/kg) were given to rats with established arthritis. The model of arthritis was characterized using an index of arthritis, with hematological, biological, molecular, and histopathological parameters. Treatment with chrysin significantly reduced the arthritis score, inflammatory cells, erythrocyte sedimentation rate, and rheumatoid factor. Chrysin also reduced the mRNA levels of tumor necrosis factor, nuclear factor kappa-B, and toll-like recepter-2 and increased anti-inflammatory cytokines interleukin-4 and -10, as well as the hemoglobin levels. Using histopathology and microscopy, chrysin reduced the severity of arthritis in joints, infiltration of inflammatory cells, subcutaneous inflammation, cartilage erosion, bone erosion, and pannus formation. Chrysin showed comparable effects to piroxicam, which is used for the treatment of rheumatoid arthritis. The results showed that chrysin possesses anti-inflammatory and immunomodulatory effects that make it a potential drug for the treatment of arthritis.

Antioxidant and Anti-Inflammatory Properties of Phytochemicals Found in the Yucca Genus

The Yucca genus encompasses about 50 species native to North America. Species within the Yucca genus have been used in traditional medicine to treat pathologies related to inflammation. Despite its historical use and the popular notion of its antioxidant and anti-inflammatory properties, there is a limited amount of research on this genus. To better understand these properties, this work aimed to analyze phytochemical composition through documentary research. This will provide a better understanding of the molecules and the mechanisms of action that confer such antioxidant and anti-inflammatory properties. About 92 phytochemicals present within the genus have reported antioxidant or anti-inflammatory effects. It has been suggested that the antioxidant and anti-inflammatory properties are mainly generated through its free radical scavenging activity, the inhibition of arachidonic acid metabolism, the decrease in TNF-α (Tumor necrosis factor-α), IL-6 (Interleukin-6), iNOS (Inducible nitric oxide synthase), and IL-1β (Interleukin 1β) concentration, the increase of GPx (Glutathione peroxidase), CAT (Catalase), and SOD (Superoxide dismutase) concentration, and the inhibition of the MAPK (Mitogen-Activated Protein Kinase), and NF-κB (Nuclear factor kappa B), and the activation of the Nrf2 (Nuclear factor erythroid 2–related factor) signaling pathway. These studies provide evidence of its use in traditional medicine against pathologies related to inflammation. However, more models and studies are needed to properly understand the activity of most plants within the genus, its potency, and the feasibility of its use to help manage or treat chronic inflammation.

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.

Co-Administration of Nanowired Monoclonal Antibodies to Inducible Nitric Oxide Synthase and Tumor Necrosis Factor Alpha Together with Antioxidant H-290/51 Reduces SiO2 Nanoparticles-Induced Exacerbation of Pathophysiology of Spinal Cord Trauma

Military personnel are often exposed to silica dust during combat operations across the globe. Exposure to silica dust in US military or service personnel could cause Desert Strom Pneumonitis also referred to as Al Eskan disease causing several organs damage and precipitate autoimmune dysfunction. However, the effects of microfine particles of sand inhalation-induced brain damage on the pathophysiology of traumatic brain or spinal cord injury are not explored. Previously intoxication of silica nanoparticles (50-60 nm size) is shown to exacerbates spinal cord injury induces blood-spinal cord barrier breakdown, edema formation and cellular changes. However, the mechanism of silica nanoparticles-induced cord pathology is still not well known. Spinal cord injury is well known to alter serotonin (5-hydroxytryptamine) metabolism and induce oxidative stress including upregulation of nitric oxide synthase and tumor necrosis factor alpha. This suggests that these agents are involved in the pathophysiology of spinal cord injury. In this review, we examined the effects of combined nanowired delivery of monoclonal antibodies to neuronal nitric oxide synthase (nNOS) together with tumor necrosis factor alpha (TNF-α) antibodies and a potent antioxidant H-290/51 to induce neuroprotection in spinal cord injury associated with silica nanoparticles intoxication. Our results for the first time show that co-administration of nanowired delivery of antibodies to nNOS and TNF-α with H-290/51 significantly attenuated silica nanoparticles-induced exacerbation of spinal cord pathology, not reported earlier.

Chrysin-phospholipid complex-based solid dispersion for improved anti-aging and neuroprotective effects in mice

The present study aimed to improve the neuroprotective effect of chrysin (CHR) by combining two formulation techniques, phospholipid (PL) complexation and solid dispersion (SD). CHR-phospholipid complex (CHR-PLC) was prepared through solvent evaporation. The molar ratio CHR/PL (1:3), which exhibited the highest complexation efficiency, was selected for the preparation of CHR-PLC loaded SD (CHR-PLC-SD) with 2-hydroxypropyl β cyclodextrin (2-HPβCD) and polyvinylpyrrolidone 8000. CHR-PLC/2-HPβCD (1:2, w/w) displayed the highest aqueous solubility of CHR (5.86 times more than that of plain CHR). CHR-SD was also prepared using 2-HPβCD for comparison. The in vitro dissolution of CHR-PLC-SD4 revealed an enhancement in the dissolution rate over CHR-PLC (1:3), CHR-SD, and plain CHR by six times. The optimum formulations and plain CHR were evaluated for their neuroprotective effect on brain aging induced by D-galactose in mice. The results demonstrated a behavioral activity elevation, an increase of AMPK, LKB1, and PGC1α brain contents as well as a reduction of AGEs, GFAP, NT-3, TNF-α, and NF-κβ brain contents when compared with those of the D-galactose control group. Thus, the developed formulations stimulated neurogenesis and mitochondrial biogenesis as well as suppressed neuroinflammation and neurodegeneration. The order of activity was as follows: CHR-PLC-SD4 > CHR-PLC (1:3) > CHR-SD > plain CHR.

Potential protective effects of chrysin against immunotoxicity induced by diazinon

Acute intoxication with diazinon (DZN) as a pesticide causes mortality and morbidity annually. This study shows the impact of sub-acute toxicity of DZN 20 mg/kg and the protective activities of chrysin (CH) as a flavone under the flavonoids family (12.5, 25 and 50 mg/kg) were assessed on BALB/c mouse immune system. The changes in morphological and functional properties of the immune system on thymus, spleen and liver histopathology, sub-populations of T lymphocytes, cytokines levels, transcription factors, complement function, phagocytosis, specific and total antibody productions were considered. The histopathological effects of DZN on the spleen and thymus were not significant, but the liver was damaged remarkably. In the presence of CH, the toxic effect of DZN is suppressed. DZN significantly decreased the number of whole blood TCD4⁺, TCD8⁺ and NK cells and suppressed the phagocytosis, delayed-type hypersensitivity (DTH) responses to sheep red blood cell (SRBC). Furthermore, it suppressed specific anti-SRBC-Ab, total IgG and IgM production, T-bet expression, and IFN-γ production. In contrast, DZN did not significantly affect complement function and the number of NK cells, TCD4⁺ and TCD8⁺ splenocytes. However, it potentiated the expression of GATA-3, ROR-γt and FOXP3 gene expression and consequently produced IL-4, IL-10, IL-17 and TGF-β in whole blood. CH not only significantly increased the variables mentioned above at 12.5, 25 and 50 mg/kg but also could overcome the toxic effects of DZN on whole blood lymphocyte sub-populations and specific and total Ab production in 25 and 50 mg/kg concentrations, phagocytosis and DTH responses in 50 mg/kg, and modulation of the transcription factors and cytokine production, mainly in 25 and 50 mg/kg. In conclusion, DZN in sub-acute doses could remarkably deteriorate immune responses. However, CH can overcome the toxic effects of DZN on the immune components and functions of the immune system.

Flavonoids regulate tumor-associated macrophages - From structure-activity relationship to clinical potential (Review)

In recent years, the strategy for tumor therapy has changed from focusing on the direct killing effect of different types of therapeutic agents on cancer cells to the new mainstream of multi-mode and -pathway combined interventions in the microenvironment of the developing tumor. Flavonoids, with unique tricyclic structures, have diverse and extensive immunomodulatory and anti-cancer activities in the tumor microenvironment (TME). Tumor-associated macrophages (TAMs) are the most abundant immunosuppressive cells in the TME. The regulation of macrophages to fight cancer is a promising immunotherapeutic strategy. This study covers the most comprehensive cognition of flavonoids in regulating TAMs so far. Far more than a simple list of studies, we try to dig out evidence of crosstalk at the molecular level between flavonoids and TAMs from literature, in order to discuss the most relevant chemical structure and its possible relationship with the multimodal pharmacological activity, as well as systematically build a structure-activity relationship between flavonoids and TAMs. Additionally, we point out the advantages of the macro-control of flavonoids in the TME and discuss the potential clinical implications as well as areas for future research of flavonoids in regulating TAMs. These results will provide hopeful directions for the research of antitumor drugs, while providing new ideas for the pharmaceutical industry to develop more effective forms of flavonoids.

Chrysin-Loaded Chitosan Nanoparticle-Mediated Neuroprotection in Aβ1-42-Induced Neurodegenerative Conditions in Zebrafish

Amyloid β plaques and neurofibrillary tangles are the characteristic features of Alzheimer's disease (AD). Plaques of amyloid β play a pivotal role in affecting cognitive functions and memory. Alzheimer's disease is a progressive neurodegenerative disease and is one of the leading causes of dementia worldwide. Several treatment strategies focusing on the amyloid cascade have been implemented to treat AD. The blood-brain barrier (BBB) poses the main obstructive barrier by refraining drugs from penetrating the brain. Nanotechnology is a promising research field for brain drug delivery using nanosized particles. Zebrafish is emerging as a model of interest to elaborate on brain targeting and nanotechnology-based therapeutics for neurodegenerative diseases. In the current study, we have synthesized and characterized chrysin-loaded chitosan nanoparticles (Chr-Chi NPs) and evaluated them for neuroprotection against amyloid-β-induced toxicity. We find that treatment with Chr-Chi NPs helps to retain memory, cognition, and synaptic connections, which are otherwise compromised due to Aβ_1-42 toxicity. The NPs further help in reducing aggregates of amyloid β, thus decreasing neuronal death and generation of reactive oxygen species (ROS). Taken together, our study brings to light a novel strategy for treating AD by a combined action on the neurons and amyloid aggregates mediated by chrysin and chitosan, respectively. Chr-Chi NPs, therefore, have the potential to provide a beneficial combinatorial treatment strategy for AD.

Ameliorative impacts of chrysin against gibberellic acid-induced liver and kidney damage through the regulation of antioxidants, oxidative stress, inflammatory cytokines, and apoptosis biomarkers

Gibberellic acid (GA3), a widely known plant growth regulator, has been mostly used in agriculture. Little is known regarding its toxicity or the impact of its metabolic mechanism on human health. The current study examined the protective impact of chrysin against GA3-induced liver and kidney dysfunctions at biochemical, molecular, and histopathological levels. Forty male albino rats were allocated into 4 groups. The control group received saline; the chrysin group received 50 mg/kg/BW orally daily for 4 weeks; the GA3 group received 55 mg/kg/BW GA3 via daily oral gavage for 4 weeks, and the protective group (chrysin + GA3) was administered both chrysin and GA3 at the same dosage given in chrysin and GA3 groups. Chrysin was administered 1 h earlier than GA3. The GA3 induced liver and kidney injuries as proven by the elevation of hepatic and renal markers with a significant increase in malondialdehyde levels. Furthermore, a decrease of catalase and glutathione was reported in the GA3-administered rats. Pre-administration of chrysin significantly protected the hepatorenal tissue against the deleterious effects of GA3. Chrysin restored the hepatorenal functions and their antioxidant ability to normal levels. Moreover, chrysin modulated the hepatorenal toxic effects of GA3 at the molecular level via the upregulation of the antiapoptotic genes, interleukin-10 (IL-10), hemoxygenase-1, and nuclear factor erythroid 2-related factor 2 expressions; the downregulation of the kidney injury molecule-1 and caspase-3 mRNA expressions; and a decrease in IL-1β and tumor necrosis factor-α secretions. Additionally, the pre-administration of chrysin effectively attenuated the GA3-induced hepatorenal histopathological changes by regulating the immunoexpression of cytochrome P450 2E1 (CYP2E1) and pregnane X receptor, resulting in normal values at the cellular level. In conclusion, chrysin attenuated GA3-induced oxidative hepatorenal injury by inhibiting free-radical production and cytokine expression as well as by modulating the antioxidant, apoptotic, and antiapoptotic activities. Chrysin is a potent hepatorenal protective agent to antagonize oxidative stress induced by GA3.

Chrysin-Loaded Microemulsion: Formulation Design, Evaluation and Antihyperalgesic Activity in Mice

Chrysin is a bioactive flavonoid found in pollens, passion flowers, honey, royal jelly, and propolis, which is commonly used as an ingredient in natural food supplements and is primarily responsible for their pharmacological properties. A transparent chrysin-loaded microemulsion (CS-ME) prepared through a ternary phase diagram was evaluated for use as an antihyperalgesic formulation. It was formulated with 40% Labrasol® (surfactant), 5% isopropyl myristate (oil phase) and 55% water (aqueous phase) and classified as an oil-in-water (O/W) microsized system (74.4 ± 15.8 nm). Its negative Zeta potential (−16.1 ± 1.9 mV) was confirmed by polarized light microscopy and dynamic light scattering analysis. In vitro studies in Franz-type static diffusion cells showed that chrysin release from CS-ME followed zero-order kinetics. Oral administration of CS-ME in mice resulted in a statistically significantly reduction (p < 0.05) in carrageenan-induced mechanical hyperalgesia compared to the control group. Treatment with CS-ME also showed anti-inflammatory activity by significantly decreasing the TNF-α level (p < 0.01) and increasing that of IL-10 (p < 0.05) compared to the control group. These results suggest that the proposed microsystem is a promising vector for the release of chrysin, being able to improve its capacity to modulate inflammatory and nociceptive responses.

Experimental study on the effect of chrysin on skin injury induced by amiodarone extravasation in rats

OBJECTIVE

Amiodarone is the first choice for the treatment of arrhythmia, but it is easy to cause extravasation during infusion, after extravasation, it often cause skin injury. The healing of skin injury induced by amiodarone is an inflammatory process. Chrysin, a natural flavonoid, has been investigated to have anti-inflammatory and antioxidant effects. It was reported that chrysin can promote wound healing. So this study aims to investigate the effect of chrysin on amiodarone extravasation-induced skin injury model in rats.

METHODS

The rat model of skin extravasation injury was established by subcutaneous injection of 0.5 mL of amiodarone. After successful modeling, the rats were randomly assigned to the five groups: control group, 10% DMSO group, and low-dose, medium-dose, and high-dose chrysin groups (10, 20 and 40 mg/mL). The extravasation injury model was given locally on the same day for seven days. On day 0, 3, 7 and 10 of administration, the lesion's image were taken to calculate the area, and the tissue of the lesion were collected for H&E staining. Then, the level of IL-6 and TNF-α were measured by ELISA, and the protein expression level of bFGF in the wound tissue were detected by immunohistochemical staining.

RESULTS

It was found that chrysin groups (20 and 40 mg/mL) compared to contronl group and 10% DMSO solvent group significantly decreased area injury, IL-6 and TNF-α(P < 0.05) on day 3, 7, 10. On the other hand, the chrysin group (40 mg/mL) compared to contronl group and 10% DMSO group significantly increase bFGF(P < 0.05) on day 3, 7.

CONCLUSION

Chrysin were effective in reducing injury area, reducing inflammation, and promoting the secretion of bFGF, it can promote the healing of skin injury induced by amiodarone extravasation in rats. These findings provide a good theoretical and experimental basis for the prevention and treatment of amiodarone extravasation-induced skin injury, and provide evidence for finding potential healing agents for the prevention and treatment of amiodarone and other corrosive extravasation-induced injuries from the molecular and cytological levels, thus solving the clinical problems.

Inflammation after spinal cord injury: a review of the critical timeline of signaling cues and cellular infiltration

Traumatic spinal cord injury (SCI) is a devastating neurological condition that results in a loss of motor and sensory function. Although extensive research to develop treatments for SCI has been performed, to date, none of these treatments have produced a meaningful amount of functional recovery after injury. The primary injury is caused by the initial trauma to the spinal cord and results in ischemia, oxidative damage, edema, and glutamate excitotoxicity. This process initiates a secondary injury cascade, which starts just a few hours post-injury and may continue for more than 6 months, leading to additional cell death and spinal cord damage. Inflammation after SCI is complex and driven by a diverse set of cells and signaling molecules. In this review, we utilize an extensive literature survey to develop the timeline of local immune cell and cytokine behavior after SCI in rodent models. We discuss the precise functional roles of several key cytokines and their effects on a variety of cell types involved in the secondary injury cascade. Furthermore, variations in the inflammatory response between rats and mice are highlighted. Since current SCI treatment options do not successfully initiate functional recovery or axonal regeneration, identifying the specific mechanisms attributed to secondary injury is critical. With a more thorough understanding of the complex SCI pathophysiology, effective therapeutic targets with realistic timelines for intervention may be established to successfully attenuate secondary damage.

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 Ameliorates Cyclosporine-A-Induced Renal Fibrosis by Inhibiting TGF-β1-Induced Epithelial-Mesenchymal Transition

Cyclosporine A (CsA) is a nephrotoxicant that causes fibrosis via induction of epithelial-mesenchymal transition (EMT). The flavonoid chrysin has been reported to have anti-fibrotic activity and inhibit signaling pathways that are activated during EMT. This study investigated the nephroprotective role of chrysin in the prevention of CsA-induced renal fibrosis and elucidated a mechanism of inhibition against CsA-induced EMT in proximal tubule cells. Treatment with chrysin prevented CsA-induced renal dysfunction in Sprague Dawley rats measured by blood urea nitrogen (BUN), serum creatinine and creatinine clearance. Chrysin inhibited CsA-induced tubulointerstitial fibrosis, characterized by reduced tubular damage and collagen deposition. In vitro, chrysin significantly inhibited EMT in LLC-PK₁ cells, evidenced by inhibition of cell migration, decreased collagen expression, reduced presence of mesenchymal markers and elevated epithelial junction proteins. Furthermore, chrysin co-treatment diminished CsA-induced TGF-β₁ signaling pathways, decreasing Smad 3 phosphorylation which lead to a subsequent reduction in Snail expression. Chrysin also inhibited activation of the Akt/ GSK-3β pathway. Inhibition of both pathways diminished the cytosolic accumulation of β-catenin, a known trigger for EMT. In conclusion, flavonoids such as chrysin offer protection against CsA-induced renal dysfunction and interstitial fibrosis. Chrysin was shown to inhibit CsA-induced TGF-β₁-dependent EMT in proximal tubule cells by modulation of Smad-dependent and independent signaling pathways.

An updated review on the versatile role of chrysin in neurological diseases: Chemistry, pharmacology, and drug delivery approaches

Neurological diseases are responsible for a large number of morbidities and mortalities in the world. Flavonoids are phytochemicals that possess various health-promoting impacts. Chrysin, a natural flavonoid isolated from diverse fruits, vegetables, and even mushrooms, has several pharmacological activities comprising antioxidant, anti-inflammatory, antiapoptotic, anticancer, and neuroprotective effects. The current study was designed to review the relationship between chrysin administration and neurological complications by discussing the feasible mechanism and signaling pathways. Herein, we mentioned the sources, pharmacological properties, chemistry, and drug delivery systems associated with chrysin pharmacotherapy. The role of chrysin was discussed in depression, anxiety, neuroinflammation, Alzheimer's disease, Parkinson's disease, Huntington's disease, epilepsy, cerebral ischemia, spinal cord injury, neuropathy, Multiple Sclerosis, and Guillain-Barré Syndrome. The findings indicate that chrysin has protective effects against neurological conditions by modulating oxidative stress, inflammation, and apoptosis in animal models. However, more studies should be done to clear the neuroprotective effects of chrysin.

Anti-Inflammation Activity of Flavones and Their Structure-Activity Relationship

Flavones are an important class of bioactive constituents in foods, and their structural diversity enables them to interact with different targets. In particular, flavones are known for their anti-inflammatory activity. Herein, we summarized commonly applied in vitro, in vivo, and clinical models in testing anti-inflammatory activity of flavones. The anti-inflammatory structure-activity relationship of flavones was systematically mapped and supported with cross comparisons of that with flavanones, flavanols, and isoflavones. Hydroxyl groups (-OH) are indispensable for the anti-inflammatory function of flavones, and -OH at the C-5 and C-4' positions enhance while -OH at the C-6, C-7, C-8, and C-3' positions attenuate their activity. Moreover, the C2-C3 single bond, -OH at the C-3 and B-ring positions undermine flavone aglycones' activity. Most of the flavone aglycones function through NF-κB, MAPK, and JNK-STAT pathways, and their possible cell binding targets are kinase, aryl hydrocarbon receptor (AhR), G-protein coupled receptors, and estrogen receptors. However, the structure and anti-inflammatory activity relationship of flavones were unclear, and further research shall be conducted to close the gap in order to guide development of evidence-based functional foods.

On the therapeutic targets and pharmacological treatments for pain relief following spinal cord injury: A mechanistic review

Spinal cord injury (SCI) is globally considered as one of the most debilitating disorders, which interferes with daily activities and life of the affected patients. Despite many developments in related recognizing and treating procedures, post-SCI neuropathic pain (NP) is still a clinical challenge for clinicians with no distinct treatments. Accordingly, a comprehensive search was conducted in PubMed, Medline, Scopus, Web of Science, and national database (SID and Irandoc). The relevant articles regarding signaling pathways, therapeutic targets and pharmacotherapy of post-SCI pain were also reviewed. Data were collected with no time limitation until November 2020. The present study provides the findings on molecular mechanisms and therapeutic targets, as well as developing the critical signaling pathways to introduce novel neuroprotective treatments of post-SCI pain. From the pathophysiological mechanistic point of view, post-SCI inflammation activates the innate immune system, in which the immune cells elicit secondary injuries. So, targeting the critical signaling pathways for pain management in the SCI population has significant importance in providing new treatments. Indeed, several receptors, ion channels, excitatory neurotransmitters, enzymes, and key signaling pathways could be used as therapeutic targets, with a pivotal role of n-methyl-D-aspartate, gamma-aminobutyric acid, and inflammatory mediators. The current review focuses on conventional therapies, as well as crucial signaling pathways and promising therapeutic targets for post-SCI pain to provide new insights into the clinical treatment of post-SCI pain. The need to develop innovative delivery systems to treat SCI is also considered.

Chrysin prevents lipopolysaccharide-induced acute lung injury in mice by suppressing the IRE1α/TXNIP/NLRP3 pathway

Acute lung injury (ALI) remains a serious challenge in the intensive care unit. Inflammation plays a key role in the progression of ALI. Chrysin (CHR) is a natural flavonoid with anti-inflammatory functions. We investigated the anti-inflammatory effects in a mouse model of ALI induced by lipopolysaccharide (LPS), and identified the underlying mechanisms of its action. Following CHR administration, mice were challenged with LPS intratracheally for 6 h to induce ALI. Compared to mice challenged with LPS alone, the presence of CHR showed a reduction in the development of lung injuries, as confirmed by histopathological observation. Pre-treatment with CHR attenuated inflammation by reducing the production of myeloperosidase (MPO), and pro-inflammatory cytokine levels in the lung and bronchoalveolar lavage fluid (BALF). Furthermore, CHR improved lung edema by reducing the vascular permeability, as demonstrated by less evans blue staining in the lung tissue and low levels of protein in BALF. In addition, our results proved that CHR improved the antioxidant capacity by increasing the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the lung tissue. Results of western blot assays suggested that CHR suppressed the LPS-induced expression of glucose-regulated protein 78 (GRP78) and phosphorylated inositol-requiring enzyme 1α (p-IRE1α). We also found that CHR suppressed the expression of thioredoxin interaction protein (TXNIP), nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) and cleaved caspase-1. In conclusion, CHR improved vascular permeability and mitigated the inflammatory response of lung tissue by suppressing the IRE1α/TXNIP/NLRP3 pathway, thereby alleviating LPS-induced ALI in the lungs of mice.

Molecular Action of Polyphenols in Leukaemia and Their Therapeutic Potential

Leukaemia is a malignant disease of the blood. Current treatments for leukaemia are associated with serious side-effects. Plant-derived polyphenols have been identified as potent anti-cancer agents and have been shown to work synergistically with standard chemotherapy agents in leukaemia cell lines. Polyphenols have multiple mechanisms of action and have been reported to decrease cell proliferation, arrest cell cycle and induce apoptosis via the activation of caspase (3, 8 and 9); the loss of mitochondrial membrane potential and the release of cytochrome c. Polyphenols have been shown to suppress activation of transcription factors, including NF-kB and STAT3. Furthermore, polyphenols have pro-oxidant properties, with increasing evidence that polyphenols inhibit the antioxidant activity of glutathione, causing oxidative DNA damage. Polyphenols also induce autophagy-driven cancer cell death and regulate multidrug resistance proteins, and thus may be able to reverse resistance to chemotherapy agents. This review examines the molecular mechanism of action of polyphenols and discusses their potential therapeutic targets. Here, we discuss the pharmacological properties of polyphenols, including their anti-inflammatory, antioxidant, anti-proliferative, and anti-tumour activities, and suggest that polyphenols are potent natural agents that can be useful therapeutically; and discuss why data on bioavailability, toxicity and metabolism are essential to evaluate their clinical use.

Neuroprotective Effects of Chrysin Mediated by Estrogenic Receptors Following Cerebral Ischemia and Reperfusion in Male Rats

Introduction

Ischemic stroke is one of the leading causes of morbidity and mortality worldwide. Neuroprotective strategies were reported to attenuate cognitive deficits after ischemic incidents. Here we studied the neuroprotective potential of chrysin in a rat model of cerebral Ischemia/Reperfusion (I/R) in the presence or absence of Estrogen Receptors (ERs).

Methods

Adult male Wistar rats were pretreated with chrysin (CH) (CH; 30 mg/kg; gavage; for 21 consecutive days) alone or with selective ERs antagonists (ERα antagonist MPP; ERβ antagonist PHTPP; IP) or nonselective ERs antagonist (ICI182780; IP). Then, the bilateral common carotid arteries were occluded for 20 min, which was followed by 72 h reperfusion. Subsequently, cognitive performance was evaluated by Morris Water Maze (MWM) and shuttle box tasks, and afterward, their hippocampi were removed for ELISA assays and H&E staining. Oxidative indicators Malondialdehyde (MDA) and Glutathione Peroxidase (GPx), as well as inflammation mediators interleukin (IL)-1β and tumor necrosis factor-alpha (TNFα), were measured using commercial kits.

Results

Results of the current study showed that the anti-oxidative and anti-inflammatory properties of CH are possible mechanisms that could improve cognitive deficits and prevent neuronal cell death following I/R (P<0.001). These effects were reversed by ICI182780 (P>0.05). Furthermore, when chrysin was co-treated with ERβ antagonist, PHTPP showed a weak neuroprotective effect in I/R rats. However, these parameters were not significantly different when chrysin was combined with ERα antagonist MPP.

Conclusion

Our data confirm that chrysin could potentially serve as a neuroprotective agent against devastating effects of cerebral I/R injury, which may be mediated via its interaction with ERs, especially ERβ.

Neuro-regenerative potential of dental stem cells: a concise review

This review will summarize the research information regarding the regenerative potential of dental stem cells for the treatment of neurodegenerative disorders. As compared to existing treatment modalities, the stem cell therapy seems promising, and accumulating evidences about the differentiation of stem cells into various lineages are proving it. The incidence of neurodegenerative diseases such as Alzheimer's, Parkinson's, stroke, and peripheral neuropathy is increasing due to the rise in life expectancies of people which have put a huge burden on economies. Finding a promising treatment could benefit not only the patients but also the communities. Dental stem cells hold a great potential to differentiate into neuronal cells. Many studies have reported the differentiation potential of the dental stem cells with the presence of neuronal lineage markers. In this review, we conferred how the use of dental stem cells can benefit the above-mentioned bedridden diseases.

Targeting apoptosis and autophagy following spinal cord injury: Therapeutic approaches to polyphenols and candidate phytochemicals

Spinal cord injury (SCI) is a neurological disorder associated with the loss of sensory and motor function. Understanding the precise dysregulated signaling pathways, especially apoptosis and autophagy following SCI, is of vital importance in developing innovative therapeutic targets and treatments. The present study lies in the fact that it reveals the precise dysregulated signaling mediators of apoptotic and autophagic pathways following SCI and also examines the effects of polyphenols and other candidate phytochemicals. It provides new insights to develop new treatments for post-SCI complications. Accordingly, a comprehensive review was conducted using electronic databases including, Scopus, Web of Science, PubMed, and Medline, along with the authors' expertise in apoptosis and autophagy as well as their knowledge about the effects of polyphenols and other phytochemicals on SCI pathogenesis. The primary mechanical injury to spinal cord is followed by a secondary cascade of apoptosis and autophagy that play critical roles during SCI. In terms of pharmacological mechanisms, caspases, Bax/Bcl-2, TNF-α, and JAK/STAT in apoptosis along with LC3 and Beclin-1 in autophagy have shown a close interconnection with the inflammatory pathways mainly glutamatergic, PI3K/Akt/mTOR, ERK/MAPK, and other cross-linked mediators. Besides, apoptotic pathways have been shown to regulate autophagy mediators and vice versa. Prevailing evidence has highlighted the importance of modulating these signaling mediators/pathways by polyphenols and other candidate phytochemicals post-SCI. The present review provides dysregulated signaling mediators and therapeutic targets of apoptotic and autophagic pathways following SCI, focusing on the modulatory effects of polyphenols and other potential phytochemical candidates.

Electro-Acupuncture Inhibits p66Shc-Mediated Oxidative Stress to Facilitate Functional Recovery After Spinal Cord Injury

Oxidative stress is the core problem in improving secondary spinal cord injury (SCI). To investigate the effect of electro-acupuncture with different frequencies on neuroinflammation, oxidative stress injury, as well as related signaling pathways, male Sprague-Dawley (SD) rats were induced using operation for model SCI and then treated with electrical stimulation at low frequency (2 mA, 0.2 Hz), medium frequency (2 mA, 50 Hz), and high frequency (2 mA, 100 Hz), respectively. Here, we first demonstrated that the JNK/p66^Shc signal pathway promoted ROS generation and inhibited the anti-oxidation effect of FoxO3a to induce oxidative stress damage after SCI and the mechanism of electro-acupuncture in anti-oxidative stress. Electro-acupuncture facilitated functional recovery after SCI and improved the apoptosis of neurons. Furthermore, p38MAPK-mediated microglia activation and inflammatory reaction and JNK/p66^Shc-mediated ROS generation and oxidative stress damage were both attenuated by electro-acupuncture. However, the inhibitory effect of electro-acupuncture on p38MAPK was enslaved to the acupuncture frequency, but the ROS generation and phosphorylation of p66^Shc were effectively inhibited by electro-acupuncture. Therefore, the activation of JNK/p66^Shc promoted the ROS-induced oxidative stress damage after SCI, and inhibiting the phosphorylation of p66^Shc-mediated oxidative stress was the key target of electro-acupuncture to facilitate functional recovery SCI, but not p38MAPK.

Chrysin attenuates traumatic brain injury-induced recognition memory decline, and anxiety/depression-like behaviors in rats: Insights into underlying mechanisms

RATIONALE

Cortical and hippocampal neuronal apoptosis and neuroinflammation are associated with behavioral deficits following traumatic brain injury (TBI).

OBJECTIVES

The present study was designed to investigate the potential protective effects of flavonoid chrysin against TBI-induced vestibulomotor impairment, exploratory/locomotor dysfunctions, recognition memory decline, and anxiety/depression-like behaviors, as well as the verified possible involved mechanisms.

METHODS

Chrysin (25, 50, or 100 mg/kg/day; P.O.) was administered to rats immediately after diffuse TBI induction, and it was continued for 3 or 14 days. Behavioral functions were assessed by employing standard behavioral paradigms at scheduled points in time. Three days post-TBI, inflammation status was assayed in both cerebral cortex and hippocampus using ELISA kits. Moreover, apoptosis and expression of Bcl-2 family proteins were examined by TUNEL staining and immunohistochemistry, respectively.

RESULTS

The results indicated that treatment with chrysin improved vestibulomotor dysfunction, ameliorated recognition memory deficit, and attenuated anxiety/depression-like behaviors in the rats with TBI. Chrysin treatment also modulated inflammation status, reduced apoptotic index, and regulated Bcl-2 family proteins expression in the brains of rats with TBI.

CONCLUSIONS

In conclusion, the results suggest that chrysin could be beneficial for protection against TBI-associated behavioral deficits, owing to its anti-apoptotic and anti-inflammatory properties.

Protective Effect of Chrysin, a Dietary Flavone against Genotoxic and Oxidative Damage Induced by Mitomycin C in Balb/C Mice

Anticancer drugs, such as Mitomycin C (MMC), can interact with biological molecules and cause genetic damage in normal cells. In this respect, we investigated the potential of chrysin, a flavone known as a potent scavenger of free radicals generated by anticancer agents, to protect mice against MMC-induced genotoxicity. The amount of DNA damage in the liver, kidney and bone marrow cells, in Balb/C mice treated with MMC (6 mg/kg, i.p) and the frequency of chromosomal aberrations indicated the genotoxic effect of MMC. Besides, a significant increase in the activities of antioxidant enzymes (SOD, CAT, GPx, GST) and lipid peroxidation is revealed. On the other hand, we noticed a regression of the genotoxic effect when studying the same parameters in Balb/C mice treated with chrysin (40 mg/kg b. wt., i.p) 24 h prior to MMC (6 mg/kg, i.p) injection. This study concluded that the protective effect of chrysin against genotoxicity of MMC results partly from its antioxidant effect.

Chrysin alleviates imiquimod-induced psoriasis-like skin inflammation and reduces the release of CCL20 and antimicrobial peptides

Psoriasis is a common non-contagious chronic inflammatory skin lesion, with frequent recurrence. It mainly occurs due to aberrant regulation of the immune system leading to abnormal proliferation of skin cells. However, the pathogenic mechanisms of psoriasis are not fully understood. Although most of the current therapies are mostly efficient, the side effects can result in therapy stop, which makes the effectiveness of treatment strategies limited. Therefore, it is urgent and necessary to develop novel therapeutics. Here, we investigated the efficacy of chrysin, a plant flavonoid, which we previously reported to possess strong antioxidant and anti-inflammatory effects, against psoriasis-like inflammation. Our results revealed that chrysin significantly attenuated imiquimod-induced psoriasis-like skin lesions in mice, and improved imiquimod-induced disruption of skin barrier. Moreover, the TNF-α, IL-17A, and IL-22-induced phosphorylation of MAPK and JAK-STAT pathways, and activation of the NF-κB pathway were also attenuated by chrysin pretreatment of epidermal keratinocytes. Most importantly, chrysin reduced TNF-α-, IL-17A-, and IL-22-induced CCL20 and antimicrobial peptide release from epidermal keratinocytes. Thus, our findings indicate that chrysin may have therapeutic potential against inflammatory skin diseases. Our study provides a basis for further investigating chrysin as a novel pharmacologic agent and contributes to the academic advancement in the field of Chinese herbal medicine.

Chrysin: Pharmacological and therapeutic properties

Chrysin is a promising phytochemical that is categorized under the class of flavonoids based on its chemical structure. Naturally, it is widely present in propolis, honey, passion fruit, and even in mushrooms and other plant sources, whereas its synthetic counterparts are also being employed for pharmacological purposes. It has widely been employed in treatment of various degenerative disorders and provides cytotoxic and anti-inflammatory functions. Its antioxidant and disease preventing abilities are attributed to its structural diversity arising in ring-A and absence of oxygenation in B and C ring. In this review, the scientific studies are being reported emphasizing benefits and its allied health claims on chrysin in numerous metabolic malfunctions.

Neuroprotective role of icariin in experimental spinal cord injury via its antioxidant, anti‑neuroinflammatory and anti‑apoptotic properties

Icariin is a type of flavonoid derived from the Chinese herbal plant Epimedium sagittatum Maxim. Mounting evidence has confirmed the beneficial effects of icariin in neurological diseases, including spinal cord injury (SCI). The aim of the present study was to investigate the neuroprotective effects of icariin in SCI and the precise underlying mechanism. The weight‑drop injury technique was applied to construct an SCI model in Sprague‑Dawley rats. Icariin (35 µmol/kg) was administered orally once daily for 7 consecutive days to examine its neuroprotective effects. The Basso, Beattie and Bresnahan scoring system was used for neurobehavioral evaluation. The water content of the injured spinal cord was measured via the dry‑wet weight method. Biochemical indices were examined by colorimetric assay using commercially available kits. Western blot analysis was used to detect protein expression. Icariin significantly accelerated the recovery of the locomotor function of SCI rats and decreased spinal cord water content. Icariin also attenuated SCI‑induced pro‑apoptotic protein expression and activity, while it increased anti‑apoptotic protein levels. In addition, icariin alleviated oxidative stress in SCI rats and decreased the levels of inflammatory molecules, including interleukin (IL)‑1β, IL‑6, tumor necrosis factor‑α, nitric oxide, nuclear factor‑κB and inducible nitric oxide synthase, and increased the expression of anti‑inflammatory proteins, including NADPH‑quinone oxidoreductase‑1, heme oxygenase‑1 and nuclear factor erythroid 2‑related factor 2 in the injured spinal cord. Therefore, icariin treatment accelerated locomotor function recovery in SCI, and its protective effects may be mediated via its antioxidant, anti‑inflammatory and anti‑apoptotic bioactivity.

Therapeutic effects of chrysin in a rat model of traumatic brain injury: A behavioral, biochemical, and histological study

AIMS

Oxidative stress and apoptosis have major roles in the progression of traumatic brain injury (TBI)-associated motor and cognitive deficits. The present study was aimed to elucidate the putative effects of chrysin, a natural flavonoid compound, against TBI-induced motor and cognitive dysfunctions and possible involved mechanisms.

MAIN METHODS

Chrysin (25, 50 or 100 mg/kg) was orally administered to rats starting immediately following TBI induction by Marmarou's weight-drop technique and continuously for 3 or 14 days. Neurological functions, motor coordination, learning and memory performances, histological changes, cell apoptosis, expression of pro- and anti-apoptotic proteins, and oxidative status were assayed at scheduled time points after experimental TBI.

KEY FINDINGS

The results indicated that treatment with chrysin improved learning and memory disabilities in passive avoidance task, and ameliorated motor coordination impairment in rotarod test after TBI. These beneficial effects were accompanied by increased the concentrations of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione (GSH), decreased malondialdehyde (MDA) content, prevented neuronal loss, diminished apoptotic index, elevated the expression of anti-apoptotic Bcl-2 protein, and reduced the expression of pro-apoptotic Bax protein in the cerebral cortex and hippocampus tissues.

SIGNIFICANCE

Our findings suggest that both anti-oxidative and anti-apoptotic properties of chrysin (especially in the dose of 100 mg/kg) are possible mechanisms that improve cognitive/motor deficits and prevent neuronal cell death after TBI.

Potential Roles of Dental Pulp Stem Cells in Neural Regeneration and Repair

This review summarizes current advances in dental pulp stem cells (DPSCs) and their potential applications in the nervous diseases. Injured adult mammalian nervous system has a limited regenerative capacity due to an insufficient pool of precursor cells in both central and peripheral nervous systems. Nerve growth is also constrained by inhibitory factors (associated with central myelin) and barrier tissues (glial scarring). Stem cells, possessing the capacity of self-renewal and multicellular differentiation, promise new therapeutic strategies for overcoming these impediments to neural regeneration. Dental pulp stem cells (DPSCs) derive from a cranial neural crest lineage, retain a remarkable potential for neuronal differentiation, and additionally express multiple factors that are suitable for neuronal and axonal regeneration. DPSCs can also express immunomodulatory factors that stimulate formation of blood vessels and enhance regeneration and repair of injured nerve. These unique properties together with their ready accessibility make DPSCs an attractive cell source for tissue engineering in injured and diseased nervous systems. In this review, we interrogate the neuronal differentiation potential as well as the neuroprotective, neurotrophic, angiogenic, and immunomodulatory properties of DPSCs and its application in the injured nervous system. Taken together, DPSCs are an ideal stem cell resource for therapeutic approaches to neural repair and regeneration in nerve diseases.

Chrysin Attenuates IL-1β-Induced Expression of Inflammatory Mediators by Suppressing NF-κB in Human Osteoarthritis Chondrocytes

Osteoarthritis (OA) is a degenerative joint disease characterized by cartilage degradation and inflammation. Chrysin, a natural flavonoid extracted from honey and propolis, has been reported to have anti-inflammatory effects. However, the anti-inflammatory effects of chrysin on OA have not been reported. This study aimed to assess the effects of chrysin on human OA chondrocytes. Human OA chondrocytes were pretreated with chrysin (1, 5, 10 μM) for 2 h and subsequently stimulated with IL-1β for 24 h. Production of NO, PGE2, MMP-1, MMP-3, MMP-13, ADAMTS-4, and ADAMTS-5 was evaluated by the Griess reaction and ELISAs. The messenger RNA (mRNA) expression of COX-2, iNOS, MMP-1, MMP-3, MMP-13, ADAMTS-4, ADAMTS-5, aggrecan, and collagen-II was measured by real-time PCR. The protein expression of COX-2, iNOS, p65, p-p65, IκB-α, and p-IκB-α was detected by Western blot. The protein expression of collagen-II and p65 nuclear translocation was evaluated by immunofluorescence. We found that chrysin significantly inhibited the IL-1β-induced production of NO and PGE2; expression of COX-2, iNOS, MMP-1, MMP-3, MMP-13, ADAMTS-4, and ADAMTS-5; and degradation of aggrecan and collagen-II. Furthermore, chrysin dramatically blocked IL-1β-stimulated IκB-α degradation and NF-κB activation. Taken together, these results suggest that chrysin may be a potential agent in the treatment of OA.

Effects of Transplanted Heparin-Poloxamer Hydrogel Combining Dental Pulp Stem Cells and bFGF on Spinal Cord Injury Repair

Spinal cord injury (SCI) is one of serious traumatic diseases of the central nervous system and has no effective treatment because of its complicated pathophysiology. Tissue engineering strategy which contains scaffolds, cells, and growth factors can provide a promising treatment for SCI. Hydrogel that has 3D network structure and biomimetic microenvironment can support cellular growth and embed biological macromolecules for sustaining release. Dental pulp stem cells (DPSCs), derived from cranial neural crest, possess mesenchymal stem cell (MSC) characteristics and have an ability to provide neuroprotective and neurotrophic properties for SCI treatment. Basic fibroblast growth factor (bFGF) is able to promote cell survival and proliferation and also has beneficial effect on neural regeneration and functional recovery after SCI. Herein, a thermosensitive heparin-poloxamer (HP) hydrogel containing DPSCs and bFGF was prepared, and the effects of HP-bFGF-DPSCs on neuron restoration after SCI were evaluated by functional recovery tests, western blotting, magnetic resonance imaging (MRI), histology evaluation, and immunohistochemistry. The results suggested that transplanted HP hydrogel containing DPSCs and bFGF had a significant impact on spinal cord repair and regeneration and may provide a promising strategy for neuron repair, functional recovery, and tissue regeneration after SCI.

Neuroprotective role of chrysin in attenuating loss of dopaminergic neurons and improving motor, learning and memory functions in rats

OBJECTIVE

Selective degeneration of dopaminergic neurons is the pathological hallmark of Parkinson disease (PD). Enhanced oxidative stress, lipid peroxidation and susceptibility of dopaminergic neurons to apoptotic cellular death are the leading pathogenetic mechanisms. Chrysin is an active flavonoid. Its neuroprotective effects have been reported. This study examined the neuroprotective effects of chrysin in ameliorating the dopaminergic neuronal degeneration and motor behavioral changes in rotenone model of PD.

METHODS

Thirty Sprague-Dawley rats were assigned into three groups: Control, rotenone-treated, and rotenone+chrysin treated groups. Rotenone was given at a dose of 3 mg/kg daily intraperitoneally, and chrysin was given at a dose of 50 mg/kg daily intraperitoneally for 4 weeks. Using five neurobehavioral assessment tests, evaluation was done weekly to record the motor behavioral changes. After 4 weeks, animals were sacrificed, brains were removed, and section from striatum and substantia nigra were stained using hematoxylin and eosin and cresyl violet stains. Immunohistochemical sections were also prepared using anti-tyrosine hydroxylase (TH) antibody.

RESULTS

Rotenone-induced Parkinson like changes were evident from deteriorating motor behavior. These animals showed extensive loss of dopaminergic neurons, decreased immunoreactivity against anti-TH antibodies and number of TH positive dopaminergic neurons in the nigrostriatal region. Chrysin treated animals showed a significant reduction in motor behavioral changes, degeneration and loss of nigrostriatal dopaminergic neurons and increased immunoreactivity to anti-TH antibody.

CONCLUSION

This study concludes that chrysin confers neuroprotection in rat model of PD. It attenuates the degeneration of the nigrostriatal dopaminergic neurons and motor behavioral abnormalities.

Chrysin Induces Antidiabetic, Antidyslipidemic and Anti-Inflammatory Effects in Athymic Nude Diabetic Mice

Extensive knowledge of diabetes and its complications is helpful to find new drugs for proper treatment to stop degenerative changes derived from this disease. In this context, chrysin (5,7-dihydroxyflavone) is a natural product that occurs in a variety of flowers and fruits with anti-inflammatory and antidiabetic effects, among others. Thus, a diabetic model in athymic nude mice was developed and used to establish the ability of chrysin to decrease the secretion of pro-inflammatory cytokines. Also, it was determined the acute (50 mg/kg) and sub-acute (50 mg/kg/day/10 days) antidiabetic and antihyperlipidemic activities after the period of time treatment. Results indicate that chrysin has significant acute antihyperglycemic and antidiabetic effects in nude diabetic mice (p < 0.05). Moreover, triglyceride blood levels were reduced and IL-1β and TNF-α were diminished after 10 days’ treatment compared with control group (p < 0.05). In conclusion, it was found that chrysin could produce similar effects as metformin, a drug used for the treatment of diabetes, since both test samples decreased glucose and triglycerides levels, they impaired the generation of pro-inflammatory cytokines involved in the development of diabetes and its consequences, such as atherosclerosis and other cardiovascular diseases.

Oxysophoridine rescues spinal cord injury via anti‑inflammatory, anti‑oxidative stress and anti‑apoptosis effects

Oxysophoridine (OSR) is an alkaloid extracted from Sophora alopecuroides L and has various pharmacological activities. The present study aimed to investigate the protective effects and underlying mechanisms of OSR on spinal cord injury (SCI), a clinically common serious trauma, in a rat model. The results of the present study demonstrated that the anti‑inflammatory effect of OSR improved Basso, Beatie and Bresnahan Locomotor Rating Scale scores and reduced spinal cord tissue water contents in an SCI rat model. Inflammatory activation was measured by ELISA, and Prostaglandin E2 (PGE2), intercellular adhesion molecule‑1 (ICAM‑1), cyclooxygenase‑2 (COX‑2), nuclear factor‑κB (NF‑κB) and B‑cell lymphoma 2 (Bcl‑2)/Bcl‑2‑associated X (Bax) protein expression levels using western blotting. The results revealed that treatment with OSR reduced tumor necrosis factor‑α, interleukin (IL)‑1β, IL‑6, IL‑8 and malondialdehyde, and increased superoxide dismutase and glutathione peroxidase levels in the serum of an SCI rat model. OSR significantly reduced the protein expression of inflammation‑associated proteins PGE2, ICAM‑1, COX‑2, NF‑κB and Bcl‑2/Bax ratio in the spinal cord tissue of an SCI rat model. Furthermore, the results of the current study demonstrate that OSR ameliorates SCI via anti‑inflammatory, anti‑oxidative stress and anti‑apoptosis effects.

In vivo cellular and molecular gastroprotective mechanisms of chrysin; Emphasis on oxidative stress, inflammation and angiogenesis

Gastric ulcer is one of the major gastrointestinal disorders affecting people worldwide. Despite medical advances, management of gastric ulcer and its complications remains a challenge facing medicine nowadays. In addition, currently available medicines exhibit limited efficacy and several side effects. In the current study, the potential protective effects of chrysin -naturally occurring flavonoid - were tested against indomethacin-induced gastric ulcer model in rats. It was found that chrysin in both doses; 50 and 100mg/kg were effective in promoting mucus secretion and preventing the rise in ulcer and lesion indices, acid production and histologic changes induced by indomethacin. During investigation of the possible underlying mechanisms, chrysin significantly attenuated indomethacin-induced oxidative injury and inflammatory response. Also, chrysin activated peroxisome proliferator activated receptor-ɣ (PPAR-ɣ) leading to a phenotypic switch from pro-inflammatory M1 macrophages to the anti-inflammatory M2 macrophages that evidenced by the upregulated mRNA expression levels of PPAR-ɣ and M2 marker genes (Arg-1 and CD206) and down regulation of M1 marker genes (IL-6 and CCL3). Furthermore, chrysin promoted angiogenesis via increasing expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and cluster of differentiation-31 (CD31). Collectively, these findings indicate that chrysin possesses a potential protective effect against indomethacin-induced gastric ulcer.

Live or let die: Neuroprotective and anti-cancer effects of nutraceutical antioxidants

Diet sources are closely involved in the pathogenesis of diverse neuropsychiatric disorders and cancers, in addition to inherited factors. Currently, natural products or nutraceuticals (commonly called medical foods) are increasingly employed for adjunctive therapy of these patients. However, the potential molecular mechanisms of the nutrient efficacy remain elusive. In this review, we summarized the neuroprotective and anti-cancer mechanisms of nutraceuticals. It was concluded that the nutraceuticals exerted neuroprotection and suppressed tumor growth possibly through the differential modulations of redox homeostasis. In addition, the balance between reactive oxygen species (ROS) production and ROS elimination was manipulated by multiple molecular mechanisms, including cell signaling pathways, inflammation, transcriptional regulation and epigenetic modulation, which were involved in the therapeutic potential of nutraceutical antioxidants against neurological diseases and cancers. We specifically proposed that ROS scavenging was integral in the neuroprotective potential of nutraceuticals, while alternation of ROS level (either increase or decrease) or disruption of redox homeostasis (ROS addiction) constituted the anti-cancer property of these compounds. We also hypothesized that ROS-associated ferroptosis, a novel type of lipid ROS-dependent regulatory cell death, was likely to be a critical mechanism for the nutraceutical antioxidants. Targeting ferroptosis is advantageous to develop new nutraceuticals with more effective and lower adverse reactions for curing patients with neuropsychiatric diseases or carcinomas.

Catalpol promotes cellular apoptosis in human HCT116 colorectal cancer cells via microRNA-200 and the downregulation of PI3K-Akt signaling pathway

Catalpol is an effective active ingredient that functions as a diuretic and laxative, and exhibits blood sugar-lowering, liver protective, anti-aging and anticancer effects. In traditional Chinese medicine, catalpol is believed to be Yin nourishing. The anticancer effect of catalpol on human HCT116 colorectal cancer cells were investigated and the mechanism of action was evaluated. Cellular viability was detected using an MTT assay. Caspase-3 and caspase-9 activity, cellular apoptosis and nucleic morphology were analyzed using caspase-3 and caspase-9 activity assay kits, flow cytometric assays and DAPI staining assay, respectively. Western blot analysis was used to measure the protein expressions of phosphatidylinositol 3-kinase (PI3K), phosphorylated-protein kinase B (p-Akt) and Akt. Expression of microRNA-200 was detected using the reverse transcription-quantitative polymerase chain reaction. HCT116 cells were incubated with PI3K inhibitors in order to analyze the effect of catalpol on cell proliferation. Catalpol was able to inhibit HCT116 cell proliferation. Furthermore, catalpol induced apoptosis in HCT116 cells, which depended on the increased activities of caspase-3 and -9. In addition, catalpol reduced the expression of PI3K, p-Akt and Akt in HCT116 cells. However, downregulation of PI3K/Akt decreased the viability of HCT116 cells following treatment with catalpol and enhanced microRNA-200 expression. Catalpol promoted cellular apoptosis in human HCT116 colorectal cancer cells through upregulation of microRNA-200 expression, which depended on a downregulation of the phosphatase and tensin homolog/PI3K-Akt signaling pathway.

Allicin protects traumatic spinal cord injury through regulating the HSP70/Akt/iNOS pathway in mice

Allicin is a major component of garlic, extracted as an oily liquid. The present study was designed to investigate the beneficial effects of allicin on traumatic spinal cord injury (TSCI) in mice, and whether the effects are mediated via regulation of the heat shock protein 70 (HSP70), v-akt murine thymoma viral oncogene homolog 1 (Akt) and inducible nitric oxide synthase (iNOS) pathways. Adult BALB/c mice (30–40 g) received a laminectomy at the T9 vertebral level as a model of TSCI. In the present study, treatment of the TSCI mice with allicin significantly increased their Basso, Beattie and Bresnahan (BBB) scores (P<0.01) and reduced the spinal cord water content (P<0.01). This protective effect was associated with the inhibition of oxidative stress and inflammatory responses in TSCI mice. Western blot analysis demonstrated that allicin increased the protein levels of HSP70, increased the phosphorylation of Akt and reduced the iNOS protein expression levels in TSCI mice. Additionally, treatment with allicin significantly reduced the levels of ROS and enhanced the NADH levels in TSCI mice. Collectively, these data demonstrate that the effects of allicin on TSCI are mediated via regulation of the HSP70, Akt and iNOS pathways in mice.

Multifunction of Chrysin in Parkinson's Model: Anti-Neuronal Apoptosis, Neuroprotection via Activation of MEF2D, and Inhibition of Monoamine Oxidase-B

Chrysin, a flavonoid compound existing in several plants, is applied as a dietary supplement because of its beneficial effects on general human health and alleviation of neurological disorders. However, mechanisms underlying neuroprotection of chrysin has not been fully elucidated, and the effects of chrysin on the Parkinson's disease (PD) model in vivo have not been investigated. It is here shown that chrysin protects primary granular neurons against 1-methyl-4-phenylpyridinium ion insult via antiapoptosis by reversing the dysregulated expression of Bcl-2, Bax, and caspase 3. The mechanisms also involved activating transcriptional factor myocyte enhancer factor 2D (MEF2D) via regulation of AKT-GSK3β signaling. In this in vivo model of PD, chrysin rescued the dopaminergic neurons loss and alleviated the decrease in dopamine level induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine in mice. Moreover, chrysin markedly inhibited monoamine oxidase-B activity in vitro and in vivo. In conclusion, chrysin exerts beneficial effects to PD, possibly through multitarget mechanisms including antineuronal apoptosis, activation of the AKT-GSK3β/MEF2D pathway, and inhibition of the MAO-B activity.