In vitro and in vivo neuroprotective effect and mechanisms of glabridin, a major active isoflavan from Glycyrrhiza glabra (licorice)

The specific extraction of glabridin from licorice residues using molecular imprinting technique

The large-scale production of glycyrrhizic acid inevitably generates a large amount of licorice residues waste, which contains a wealth of active ingredients, especially glabridin, a natural preservative. However, traditional extraction methods for glabridin are often limited by bottlenecks such as time-consuming, inefficient, and insufficient specificity. To overcome these challenges, this study innovatively introduced 2-phenylimidazole as a functional monomer by computer simulations and successfully developed magnetic molecularly imprinted polymers (MMIPs) for glabridin. The adsorption capacity of MMIPs could reach 25.61 mg/g at 300 min, and the MMIPs had high specificity with an imprinting factor of 1.9. In addition, the MMIPs had high selectivity and reproducibility with a selectivity factor of 2.34, and the adsorption capacity could be maintained at 90 % after six times of repeated use. It can increase the purity of glabridin from 20 % to about 77 % in the complex environment of licorice residues, showing good specificity and promising application.

Glabridin as a selective Kv2.1 inhibitor ameliorates DPN pathology by disrupting the Aβ/Kv2.1/JNK/NF-κB/NLRP3/p-Tau pathway

Diabetic peripheral neuropathy (DPN) is a common diabetic complication. DPN has a complicated pathogenesis, and the currently clinical drugs against this disease show only limited efficacy and undesirable side effects. Thus, it is of great challenges to discover effective targets and drugs against DPN. Glabridin (GLA) is a natural prenylated isoflavone from the roots of Glycyrrhiza glabra. It exhibits a wide range of pharmacological activities including anti-inflammatory, antioxidant, cardiovascular protective, neuroprotective, hepatoprotective, anti-obesity and anti-diabetic effects, etc. In this study we investigated the beneficial effects of GLA on late-stage DPN and the underlying mechanisms. Using electrophysiological recording from CHO-Kv2.1 cells, we identified GLA as a new Kv2.1-selective inhibitor with an IC50 value of 2.07 μM. We showed that oral administration of GLA (30, 60 mg·kg-1·d-1) for 4 weeks significantly improved all neurological dysfunctions and peripheral vascular dysfunctions in DPN mice. Furthermore, we demonstrated that GLA administration improved intraepidermal nerve fiber (IENF) density damage and myelin sheath injury, promoted neurite outgrowth of DRG neurons and alleviated the apoptosis of DRG neurons in DPN mice. All these beneficial effects of GLA were deprived in Kv2.1-knockdown DPN mice specifically in the DRG and sciatic nerve tissues by injection of adeno associated virus AAV8-Kv2.1-RNAi (AAV8-Kv2.1). We showed that the levels of Aβ and hyperphosphorylated tau proteins (p-Tau) were pathologically increased in serum of DPN patients. We demonstrated that Kv2.1 channels bridged Aβ to activate NLRP3 inflammasome in Schwann cells and promote p-Tau production in DRG neurons through Schwann cells/DRG neurons crosstalk. GLA interrupted Aβ/Kv2.1/NLRP3/p-Tau axis to ameliorate the DPN-like pathology in mice. Our results support that Kv2.1 inhibition is a therapeutic strategy for DPN and highlight the potential of GLA in treating this disease.

Effect of the flavonoid compound glabridin on tachyzoites and bradyzoites of Toxoplasma gondii

BACKGROUND

Toxoplasma gondii (T. gondii) is one of the most prevalent parasites worldwide. At present, the majority of drugs used for the treatment of toxoplasmosis target the tachyzoite stage of T. gondii and are largely ineffective against bradyzoites. Furthermore, these treatments are typically accompanied by adverse events. Consequently, there is an urgent need for the development of novel drugs that are both safe and effective against T. gondii.

METHODS

A total of 20 flavonoids were preliminarily screened for their anti-T. gondii activity using microscopy. Next, the cell counting kit (CCK)-8 method was employed to assess the toxicity of glabridin (GLA) to host cells, while the RH strain of T.0gondii, which expresses β-galactosidase, was utilized to evaluate the inhibitory, anti-invasive, and antiproliferative effects of GLA on T. gondii. In addition, the Prugniaud (PRU) strain was employed to investigate the impact of GLA on the bradyzoites of T. gondii. Subsequently, the effect of GLA on the ultrastructure of T. gondii was examined via transmission electron microscopy (TEM), followed by an assessment of the influence of GLA on the autophagy and mitochondria of T. gondii through monodansylcadaverine (MDC), MitoTracker™ red CMXRos, and CM-HDCFDA and MitoSOX Red staining.

RESULTS

Among the 20 flavonoids assessed, GLA exhibited the most potent anti-T. gondii activity. Indeed, it significantly inhibited both the invasive and proliferative abilities of T. gondii, thereby disrupting its lytic cycle. Moreover, GLA markedly reduced the number of bradyzoites and concurrently inhibited cyst growth. Meanwhile, ultrastructural analysis revealed that GLA induced mitochondrial swelling, membrane rupture, and autophagy in T. gondii. Finally, fluorescent probe staining provided further evidence that GLA triggers mitochondrial dysfunction and autophagy in this parasite.

CONCLUSIONS

Our findings collectively indicate that the flavonoid compound GLA exhibits significant activity against both T. gondii tachyzoites and bradyzoites. The underlying mechanism of action potentially involves the induction of autophagy and mitochondrial dysfunction and the disruption of the membrane of T. gondii, thereby offering new avenues for treating toxoplasmosis and establishing a theoretical reference for future research.

Pathophysiology of cerebral ischemia-reperfusion injury: An overview of oxidative stress and plant-based therapeutic approaches

Stroke is a debilitating neurological disorder that causes substantial morbidity and mortality on a global scale. Ischemic stroke, the most common type, occurs when the brain's blood supply is interrupted. Oxidative stress is a key factor in stroke pathology, contributing to inflammation and neuronal cell death. As a result, there is increasing interest in the potential of plant extracts, which have been used in traditional medicine for centuries and are generally considered safe, to serve as alternative or complementary treatments for stroke. The plant extracts can target multiple pathological processes, including oxidative stress, offering neuroprotective effects. The development of highly efficient, low-toxicity, and cost-effective natural products is crucial for enhancing stroke treatment options. In this review, we examine 60 plant extracts that have been focused on the studies published from year 2000 to 2024 along with the studies' experimental models, dosages, and results. The plant extracts hold promise in modulating cerebral ischemia-reperfusion injury through counteraction of relevant pathophysiologic processes such as oxidative stress.

Online identification of chemical constituents in Mongolian medicine Zhachong-13 pills by UHPLC-Q-exactive Orbitrap MS

Zhachong-13 pills (ZC-13), as a traditional prescription of Mongolian medicine, are often used in the clinical practice of Mongolian hospitals for the treatment of stroke and rheumatic arthritis. In this experiment, UHPLC-Q-Exactive Orbitrap MS was used to explore the chemical composition of ZC-13. The results showed that 315 compounds were identified or inferred, including 56 alkaloids, 77 2-(2-phenylethyl)chromones, 61 flavonoids, 31 tannins, 8 coumarins, 16 lignans, 21 terpenoids, 5 amino acids, 19 organic acids, and 21 other components. In addition, the pharmacological activities related to anti-cerebral ischemia of these components were summarized. This result laid a foundation for further study on the pharmacodynamic material basis of ZC-13 and provided a scientific basis for the formulation of ZC-13 quality specifications.

Natural Phenolic Compounds with Neuroprotective Effects

Neurodegenerative disorders are characterized by mitochondrial dysfunction and subsequently oxidative stress, inflammation, and apoptosis that contribute to neuronal cytotoxicity and degeneration. Huntington's (HD), Alzheimer's (AD), and Parkinson's (PD) diseases are three of the major neurodegenerative diseases. To date, researchers have found various natural phytochemicals that could potentially be used to treat neurodegenerative diseases. Particularly, the application of natural phenolic compounds has gained significant traction in recent years, driven by their various biological activities and therapeutic efficacy in human health. Polyphenols, by modulating different cellular functions, play an important role in neuroprotection and can neutralize the effects of oxidative stress, inflammation, and apoptosis in animal models. This review focuses on the current state of knowledge on phenolic compounds, including phenolic acids, flavonoids, stilbenes, and coumarins, as well as their beneficial effects on human health. We further provide an overview of the therapeutic potential and mechanisms of action of natural dietary phenolics in curing neurodegenerative diseases in animal models.

The Potentiality of Natural Products and Herbal Medicine as Novel Medications for Parkinson's Disease: A Promising Therapeutic Approach

As the global population ages, the prevalence of Parkinson's disease (PD) is steadily on the rise. PD demonstrates chronic and progressive characteristics, and many cases can transition into dementia. This increases societal and economic burdens, emphasizing the need to find effective treatments. Among the widely recognized causes of PD is the abnormal accumulation of proteins, and autophagy dysfunction accelerates this accumulation. The resultant Lewy bodies are also commonly found in Alzheimer's disease patients, suggesting an increased potential for the onset of dementia. Additionally, the production of free radicals due to mitochondrial dysfunction contributes to neuronal damage and degeneration. The activation of astrocytes and the M1 phenotype of microglia promote damage to dopamine neurons. The drugs currently used for PD only delay the clinical progression and exacerbation of the disease without targeting its root cause, and come with various side effects. Thus, there is a demand for treatments with fewer side effects, with much potential offered by natural products. In this study, we reviewed a total of 14 articles related to herbal medicines and natural products and investigated their relevance to possible PD treatment. The results showed that the reviewed herbal medicines and natural products are effective against lysosomal disorder, mitochondrial dysfunction, and inflammation, key mechanisms underlying PD. Therefore, natural products and herbal medicines can reduce neurotoxicity and might improve both motor and non-motor symptoms associated with PD. Furthermore, these products, with their multi-target effects, enhance bioavailability, inhibit antibiotic resistance, and might additionally eliminate side effects, making them good alternative therapies for PD treatment.

Dietary flavonoids may have a protective and therapeutic effect in Parkinson disease: A systematic review

Parkinson disease (PD) is characterized by the loss of dopaminergic neurons because of oxidative stress and neuroinflammation. Polyphenols in vegetables, known for their high antioxidant capacity, may prevent the onset, or delay the progression of the disease; among these, flavonoids are the most abundant class of polyphenols in foods. Clinical and cohort studies have evaluated the effect of polyphenol consumption on the risk of developing PD or of attenuating the symptoms after diagnosis; therefore, it is necessary to integrate the scientific evidence into making dietary recommendations. The objective of this study was to perform a systematic review of randomized controlled trials and cohort studies that have investigated the use of polyphenols in PD. The studies were identified through the PubMed, Science Direct, Scielo, and Web of Science databases. A total of 1100 studies were found; these were analyzed and filtered by 2 independent reviewers. After completion, 5 studies were included (3 randomized controlled trials and 2 cohort studies). The consumption of flavonoids, anthocyanins, or 2-5 servings/week of specific foods (apples, red wine, blueberries, and strawberries) reduces the risk of PD and associated mortality. Treatment with licorice, curcumin, or cocoa, which are rich in flavonoids and other polyphenols, improves motor function in PD patients. No statistically significant differences were found in quality of life, disease progression or nonmotor symptoms such as cognitive ability and mood. Although cohort studies suggest a neuroprotective effect, further clinical studies are urgently needed to evaluate the effect of specific flavonoids and other polyphenols in PD.

Revisiting Licorice as a functional food in the management of neurological disorders: Bench to trend

Traditional and scientific evidence attribute numerous bioactivities of Licorice (Glycyrrhiza glabra Linn.) in aging-related disorders. In this state-of-art review, an extensive search in several databases was conducted to collect all relevant literature and comprehensively analyze Licorice's pharmacological attributes, neuroprotective properties, safety, and its mechanistic role in treating various neurological conditions. Network pharmacology was employed for the first time exploring the mechanistic role of Licorice in neurological disorders. Its neuroprotective role is attributed to phytoconstituents, including liquiritin, glycyrrhizic acid, liquiritigenin, glabridin, 18ß-glycyrrhetinic acid, quercetin, isoliquiritigenin, paratocarpin B, glycyglabrone, and hispaglabridin B, as evident from in vitro and in vivo studies. Network pharmacology analysis reveals that these compounds protect against long-term depression, aging-associated diseases, Alzheimer's disease, and other addictions through interactions with cholinergic, dopaminergic, and serotonergic proteins, validated in animal studies only. Future clinical trials are warranted as Licorice administration has a limiting factor of mild hypertension and hypokalemia. Hopefully, scientific updates on Licorice will propagate a paradigm shift in medicine, research propagation, and development of the central nervous system phytopharmaceuticals.

Plant-Derived Epi-Nutraceuticals as Potential Broad-Spectrum Anti-Viral Agents

Although the COVID-19 pandemic appears to be diminishing, the emergence of SARS-CoV-2 variants represents a threat to humans due to their inherent transmissibility, immunological evasion, virulence, and invulnerability to existing therapies. The COVID-19 pandemic affected more than 500 million people and caused over 6 million deaths. Vaccines are essential, but in circumstances in which vaccination is not accessible or in individuals with compromised immune systems, drugs can provide additional protection. Targeting host signaling pathways is recommended due to their genomic stability and resistance barriers. Moreover, targeting host factors allows us to develop compounds that are effective against different viral variants as well as against newly emerging virus strains. In recent years, the globe has experienced climate change, which may contribute to the emergence and spread of infectious diseases through a variety of factors. Warmer temperatures and changing precipitation patterns can increase the geographic range of disease-carrying vectors, increasing the risk of diseases spreading to new areas. Climate change may also affect vector behavior, leading to a longer breeding season and more breeding sites for disease vectors. Climate change may also disrupt ecosystems, bringing humans closer to wildlife that transmits zoonotic diseases. All the above factors may accelerate the emergence of new viral epidemics. Plant-derived products, which have been used in traditional medicine for treating pathological conditions, offer structurally novel therapeutic compounds, including those with anti-viral activity. In addition, plant-derived bioactive substances might serve as the ideal basis for developing sustainable/efficient/cost-effective anti-viral alternatives. Interest in herbal antiviral products has increased. More than 50% of approved drugs originate from herbal sources. Plant-derived compounds offer diverse structures and bioactive molecules that are candidates for new drug development. Combining these therapies with conventional drugs could improve patient outcomes. Epigenetics modifications in the genome can affect gene expression without altering DNA sequences. Host cells can use epigenetic gene regulation as a mechanism to silence incoming viral DNA molecules, while viruses recruit cellular epitranscriptomic (covalent modifications of RNAs) modifiers to increase the translational efficiency and transcript stability of viral transcripts to enhance viral gene expression and replication. Moreover, viruses manipulate host cells' epigenetic machinery to ensure productive viral infections. Environmental factors, such as natural products, may influence epigenetic modifications. In this review, we explore the potential of plant-derived substances as epigenetic modifiers for broad-spectrum anti-viral activity, reviewing their modulation processes and anti-viral effects on DNA and RNA viruses, as well as addressing future research objectives in this rapidly emerging field.

Glabridin ameliorates intracellular events caused by palmitic acid and alcohol in mouse hepatocytes and fast food diet and alcohol -induced steatohepatitis and fibrosis in C57BL/6J mice model

Steatohepatitis is a significant risk factor for end-stage liver disease. In this study, the therapeutic potential of Glabridin (GBD), an isoflavan derived from Glycyrrhiza glabra, is investigated in in-vitro and in-vivo models against palmitic acid (PA) or fast food (FF) diet + alcohol (EtOH). Mouse hepatocytes (AML-12 cells) were treated with PA; 250 μM + EtOH; 250 μM ± GBD (10 μM and 25 μM) for 24 h. C57BL/6J mice fed with standard chow (SC) diet, fast food (FF) diet + intermittent oral ingestion of EtOH (10-50%v/v) ± GBD (20 mg/kg and 40 mg/kg) for eight (8) weeks, were analyzed for histological features of steatohepatitis and fibrosis, biochemical indexes, and protein and gene expression studies related to oxidative stress, inflammation, lipogenesis, fibrosis, and apoptosis. GBD therapy considerably reduced intracellular events in AML-12 cells exposed to PA + EtOH. GBD treatments significantly improved body metrics, biochemical indexes, and histological features in C57BL/6J mice compared to FF + EtOH. Moreover, protein and gene expression investigations revealed a strong therapeutic effects on oxidative stress, inflammation, steatosis, fibrosis, and apoptosis -related molecular signaling cascades. In conclusion, these findings suggest that GBD has a strong therapeutic potential to be developed as anti-steatohepatitis/fibrosis medicine.

Elucidating the promising role of traditional Chinese medicine in neuroprotection against oxidative stress encompassing Alzheimer's disease

Medicinal plants are being used from time immemorial for their therapeutic benefits and have immense value in the therapy of neurodegenerative disorders. One of the most important neurological disorders is Alzheimer's disease (AD) which is a major contributor to dementia and is accompanied by abundant oxidative stress in the brain tissue. A critical pathway to target the increased oxidative stress is to administer agents with antioxidant potential. Despite currently available clinical treatments to treat AD such as cholinesterase inhibitors or NMDA antagonists which address only the symptoms and cannot hamper disease progression, no efficient available clinical treatment can break the vicious cycle of oxidative stress and neurodegeneration till date. The main objective of presenting this review is that traditional Chinese medicine (TCM) acts as a promising candidate in breaking this vicious cycle and improves the quality of life of the debilitating patients. The active constituents of various herbs in TCM including Angelica sinensis, Radix polygalae, Polygala tenuifolia, and members of the Lamiaceae family have acquired experience of managing oxidative stress as indicated in the review for more than a thousand years now, and the preclinical and clinical evidence of their therapeutic potential has been highlighted in the review. Most importantly, Chinese herbs provide a multiple-target approach rather than a single-target approach and thus can target multiple pathways involved in AD at once. The Chinese herbs can definitely untangle the issues in the current therapy regimen of AD.

Comprehensive Evaluation of Metabolism and the Contribution of the Hepatic First-Pass Effect in the Bioavailability of Glabridin in Rats

Glabridin is a bioactive isoflavan, which has a wide range of biological properties and is widely used in the market of health products and dietary supplements. However, the transformation pathway of glabridin in vivo is unclear, and the bioavailability is controversial among different studies. Therefore, a new HPLC-Q-TOF method was developed to analyze and identify the prototype and metabolites of glabridin in rats. A total of 63 compounds were identified, including hydroxylation, demethylation, acetylation, demethylation to carboxylation, glucuronidation, and sulfate conjugation, and 43 of which were new metabolites that had not been reported. Additionally, our study verified that the oral bioavailability of glabridin was 6.63 ± 2.29% in rats. Furthermore, we found that the hepatic first-pass effect was 62.12 ± 15.7% for glabridin. These results indicated that a high hepatic first-pass effect and extensive metabolism of glabridin in vivo may lead to its limited oral bioavailability.

Review on the Diverse Biological Effects of Glabridin

Glabridin is a prenylated isoflavan from the roots of Glycyrrhiza glabra Linne and has posed great impact on the areas of drug development and medicine, due to various biological properties such as anti-inflammation, anti-oxidation, anti-tumor, anti-microorganism, bone protection, cardiovascular protection, neuroprotection, hepatoprotection, anti-obesity, and anti-diabetes. Many signaling pathways, including NF-κB, MAPK, Wnt/β-catenin, ERα/SRC-1, PI3K/AKT, and AMPK, have been implicated in the regulatory activities of glabridin. Interestingly, glabridin has been considered as an inhibitor of tyrosinase, P-glycoprotein (P-gp), and CYP2E1 and an activator of peroxisome proliferator-activated receptor γ (PPARγ), although their molecular regulating mechanisms still need further investigation. However, poor water solubility and low bioavailability have greatly limited the clinical applications of glabridin. Hopefully, several effective strategies, such as nanoemulsions, microneedles, and smartPearls formulation, have been developed for improvement.

A mechanistic review of pharmacological activities of homeopathic medicine licorice against neural diseases

The use of medicinal plants has grown in popularity in recent decades because, as natural ingredients, they have fewer adverse effects and are more effective than synthetic alternatives. As a small perennial herb, Glycyrrhiza glabra L. (Licorice) has been investigated for its therapeutic efficacy against neural disorders mainly ischemic stroke as well as the neurodegenerative diseases such as dementia and Alzheimer's disease, and Parkinson's disease which has been attributed to its HMGB inhibitory function, reactive oxygen scavenging and anti-inflammatory activity. The objective of current review is to review the evidence for the pharmacological effects of licorice and its vital active components on neurological disorders and the underlying signaling networks. We reviewed Papers published from 2000.1.1 up to 2 January 2023 in web of science, Google Scholar and PubMed data bases using key words including "Licorice," "Glycyrrhiza glabra L.," "Glycyrrhizic acid," "brain," "neurodegenerative disease," "Alzheimer's," and "Parkinson" were used to search in title/abstracts. Licorice extract and/or its active components can be used safely in therapeutic doses for optimizing the management of a multiple neurodegenerative disorders, and hampering the extent of neural tissue injury and neurologic deficits subsequent to cerebrovascular accidents.

Amelioration of Brain Damage after Treatment with the Methanolic Extract of Glycyrrhizae Radix et Rhizoma in Mice

Glycyrrhizae Radix et Rhizoma (GR) is a traditional herbal medicine widely used in Asian countries. GR was the most frequently used medicine among stroke patients in Donguibogam, the most representative book in Korean medicine. In the present study, we investigated the neuroprotective effects of the GR methanolic extract (GRex) on an ischemic stroke mice model. Ischemic stroke was induced by a 90 min transient middle cerebral artery occlusion (MCAO), and GRex was administered to mice with oral gavage after reperfusion of MCA blood flow. The MCAO-induced edema and infarction volume was measured, and behavioral changes were evaluated by a novel object recognition test (NORT). Immunofluorescence stains and Western blotting identified underlying mechanisms of the protective effects of GRex. GRex post-treatment in mice with MCAO showed potent effects in reducing cerebral edema and infarction at 125 mg/kg but no effects when the dosage was much lower or higher than 125 mg/kg. GRex inhibited the decrease of spontaneous motor activity and novel object recognition functions. The neuroprotective effects of GRex on ischemic stroke were due to its regulation of inflammation-related neuronal cells, such as microglia and astrocytes.

Glabridin Plays Dual Action to Augment the Efficacy and Attenuate the Hepatotoxicity of Methotrexate in Arthritic Rats

Glabridin is chemically an isoflavane class of natural phenols and is found mainly in the roots of Glycyrrhiza glabra. It has several beneficial pharmacological actions for the management of inflammatory disorders as well as can counteract drug-induced toxic effects. On the other hand, methotrexate (MTX) is the first-line disease-modifying antirheumatic drug for the treatment of rheumatoid arthritis. However, its treatment is associated with major side effects like hepatotoxicity. In the quest to explore a suitable combination therapy that can improve the efficacy and reduce the hepatotoxicity of MTX, we hypothesized that glabridin might serve the purpose for which there is no literature precedent to date. We explored the antiarthritic efficacy of MTX in the presence or the absence of glabridin using Mycobacterium-induced arthritic model in rats. The results of reduction in paw swelling, inhibition of serum cytokines (TNF-α, IL-6, and IL-1β), and improvement in the bone joints from radiological and histopathological findings suggest that glabridin can substantially augment the antiarthritic efficacy of MTX. Further, results of concomitant glabridin treatment with MTX in the experimental time frame demonstrate that glabridin could considerably prevent the MTX-induced hepatic alteration in serum biochemical markers (SGPT and SGOT) and oxidative stress markers (malondialdehyde (MDA) and glutathione reduced (GSH)). Moreover, glabridin showed a marked effect in impeding the regulation of NF-κB/IκBα and Nrf2/Keap1 pathways in the hepatic tissues. The results of simultaneous administration of glabridin with MTX in the rat model indicate that glabridin had no pronounced effect of causing severe alteration in the pharmacokinetic behavior of MTX. In summary, glabridin can significantly potentiate the antiarthritic efficacy of MTX and can also minimize its hepatotoxicity via the inhibition of inflammation and oxidative stress. Further research should be performed to develop glabridin as a phytotherapeutics for the improved efficacy and better tolerability of MTX at the reduced dose level of MTX.

Spleen-Targeted Glabridin-Loaded Nanoparticles Regulate Polarization of Monocyte/Macrophage (Mo /Mφ ) for the Treatment of Cerebral Ischemia-Reperfusion Injury

During cerebral ischemia-reperfusion (I-R) injury, the infiltration of monocyte/macrophages (Mo /Mφ ) into the ischemic penumbra causes inflammatory damage but also regulates tissue repair in the penumbra. The regulation and balance of Mo /Mφ polarization is considered as a potential therapeutic target for treating cerebral I-R injury. Herein, these findings demonstrate that glabridin (Gla)-loaded nanoparticles (i.e., NPGla -5k) can effectively inhibit M1-polarization and enhance M2-polarization of Mo /Mφ . Positron emission tomography (PET) imaging shows that NPGla -5k can selectively accumulate in the spleen following intravenous injection. Spleen-targeted Cy5-NPGla -5k can co-localize with peripheral macrophages in the penumbra at 24 h after tail-vein injection. Interestingly, NPGla -5k treatment can reduce inflammatory damage, protect dying neurons, and improve nervous system function. The protective effect of spleen-targeted NPGla -5k against cerebral I-R injury in mice encourages an exploration of their use for clinical treatment of patients with cerebral I-R injury.

An anti-inflammatory and anti-fibrotic proprietary Chinese medicine nasal spray designated as Allergic Rhinitis Nose Drops (ARND) with potential to prevent SARS-CoV-2 coronavirus infection by targeting RBD (Delta)- angiotensin converting enzyme 2 (ACE2) binding

BACKGROUND

Since the outbreak of COVID-19 has resulted in over 313,000,000 confirmed cases of infection and over 5,500,000 deaths, substantial research work has been conducted to discover agents/ vaccines against COVID-19. Undesired adverse effects were observed in clinical practice and common vaccines do not protect the nasal tissue. An increasing volume of direct evidence based on clinical studies of traditional Chinese medicines (TCM) in the treatment of COVID-19 has been reported. However, the safe anti-inflammatory and anti-fibrotic proprietary Chinese medicines nasal spray, designated as Allergic Rhinitis Nose Drops (ARND), and its potential of re-purposing for suppressing viral infection via SARS-CoV-2 RBD (Delta)- angiotensin converting enzyme 2 (ACE2) binding have not been elucidated.

PURPOSE

To characterize ARND as a potential SARS-CoV-2 entry inhibitor for its possible preventive application in anti-virus hygienic agent.

METHODS

Network pharmacology analysis of ARND was adopted to asacertain gene targets which were commonly affected by COVID-19. The inhibitory effect of ARND on viral infection was determined by an in vitro pseudovirus assay. Furthermore, ARND was confirmed to have a strong binding affinity with ACE2 and SARS-CoV-2 spike-RBD (Delta) by ELISA. Finally, inflammatory and fibrotic cell models were used in conjunction in this study.

RESULTS

The results suggested ARND not only inhibited pseudovirus infection and undermined the binding affinity between ACE2 and the Spike protein (Delta), but also attenuated the inflammatory response upon infection and may lead to a better prognosis with a lower risk of pulmonary fibrosis. The data in this study also provide a basis for further development of ARND as an antiviral hygienic product and further investigations on ARND in the live virus, in vivo and COVID-19 patients. ARND holds promise for use in the current COVID-19 outbreak as well as in future pandemics.

CONCLUSION

ARND could be considered as a safe anti-SARS-CoV-2 agent with potential to prevent SARS-CoV-2 coronavirus infection.

Self-Assembled pH-Responsive Metal-Organic Frameworks for Enhancing the Encapsulation and Anti-Oxidation and Melanogenesis Inhibition Activities of Glabridin

Metal organic frameworks (MOFs) are formed by self-assembly of metal ions and organic ligands. A special type of MOF called ZIF-8, which is formed by self-assembly of zinc ions and 2-methylimidazole, shows excellent stability in aqueous solutions and disintegrates under acidic conditions. These properties make ZIF-8 a suitable carrier material for pH-stimulated drug delivery systems. Glabridin is an isoflavane compound that is widely present in the roots of licorice. Because of its outstanding skin whitening properties, glabridin is widely used as a whitener in the cosmetics industry. In this study, ZIF-8 was employed to encapsulate glabridin. Glabridin-loaded ZIF-8 was successfully prepared with a drug encapsulation efficiency of 98.67%. The prepared sample showed a fusiform or cruciate flower-like structure, and its size was about 3 μm. ZIF-8 enabled pH-controlled release of glabridin. Moreover, ZIF-8 encapsulation significantly enhanced the intracellular anti-oxidant activity and melanogenesis inhibitory activity of glabridin. This study provides a new approach that shows great potential to improve the biological application of glabridin.

Study on the Mechanism of Üstikuddus Sherbiti in Ischemic Cerebrovascular Diseases: Based on Network Pharmacology

This paper aims to study the potential biological mechanism of Üstikuddus Sherbiti (ÜS) in the treatment of ischemic cerebrovascular diseases (ICVD) by the network pharmacology method. Traditional Chinese Medicine Systems Pharmacology (TCMSP) database was used to obtain effective constituents of ÜS by screening eligible oral utilization, drug similarity, and blood-brain barrier permeability threshold. By drug target prediction and stroke treatment target mining, 2 target data sets were analyzed to find intersection targets and the corresponding constituents were used as active constituents. An active constituent target network and an effective constituent target network were constructed by using Cytoscape 3.7.2 software. Degree parameters of the effective constituent target network were analyzed to find important effective constituents and targets. Through protein-protein interaction (PPI) analysis/Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, potential signaling pathways of ÜS in ischemic stroke were found out. AutoDock was used for molecular docking verification. A total of 90 active constituents of ÜS were screened out. There were 10 active constituents against ICVD, including quercetin, luteolin, kaempferol, and naringenin, and 10 important targets for anticerebral ischemia, namely, PIK3CA, APP, PIK3R1, MAPK1, MAPK3, AKT1, PRKCD, Fyn, RAC1, and NF-κB1. Based on the protein interaction network, the important targets of ÜS were significantly enriched in PI3K-Akt signaling pathway, neuroactive ligand-receptor interaction pathway, Ras signaling pathway, etc. ÜS in ICVD has characteristics like multiple targets, multiple approaches, and multiple pathways. Results of molecular docking showed that the active components in ICVD had a good binding ability with the key targets. Its main biological mechanism may be related to the PI3K-Akt and Ras-MAPK centered signaling pathway. Our study demonstrated that ÜS exerted the effect of treating ICVD by regulating multiple targets and multiple channels with multiple components through the method of network pharmacology and molecular docking.

Does Resveratrol Prevent Sevoflurane Toxicity in Newborn Rats?

Inhalation anesthetics have been shown to cause neurodevelopmental disorders and neurotoxic effects. In this study, we aimed to investigate the effect of resveratrol on the possible neurotoxic effect of sevoflurane and the brain-derived neurotrophic factor (BDNF) pathway in newborn rats. The animals were divided into four groups: control, sevoflurane, sevoflurane+resveratrol 25 mg/kg, and sevoflurane+resveratrol 50 mg/kg. The groups that received anesthesia were given 3% sevoflurane for 2 h on the postnatal seventh, eighth, and ninth days. Control gas was applied to the control group. The Morris water maze (MWM) test was performed on postnatal 35th day. After performing the open field test on the postnatal 41st day, the animals were dissected, and the hippocampal BDNF levels were determined by Western blot method. In the MWM test, there was a significant decrease in the time spent in the target quadrant in the sevoflurane anesthesia group compared with control group. This reduction was reversed with the resveratrol pretreatment. Sevoflurane exposure significantly decreased hippocampal BDNF levels compared with the control group. The resveratrol 25 mg/kg pretreatment did not reverse this reduction, whereas resveratrol 50 mg/kg ameliorated this impairment. Sevoflurane did not cause any significant difference in the rats' performance in the open field test. However, 50 mg/kg resveratrol pretreatment caused a statistically significant increase in this performance. Our results showed that sevoflurane impaired learning and memory functions in newborn rats and resveratrol reversed this deterioration. Also BDNF might play a role in this beneficial effect of resveratrol.

In silico ADMET, molecular docking and molecular simulation-based study of glabridin’s natural and semisynthetic derivatives as potential tyrosinase inhibitors

Hyper-pigmentation conditions may develop due to erroneous melanogenesis cascade which leads to excess melanin production. Recently, inhibition of tyrosinase is the main focus of investigation as it majorly contributes to melanin production. This inhibition property can be exploited in medicine, agriculture, and in cosmetics. Present study aims to find a natural and safe alternative molecule as tyrosinase inhibitor. In this study, human tyrosinase enzyme was modelled due to unavailability of its crystal structure to look into the degree of efficacy of glabridin and its 15 derivatives as tyrosinase inhibitor. Docking was performed by Autodock Vina at the catalytic core enzyme. Glabridin effects on melanoma cell lines was also elucidated by analysing cytotoxicity and effect on melanin production. Computational ADME analysis was done by SwissADME. Molecular dynamic simulation was also performed to further evaluate the interaction profile of these molecules and kojic acid (positive inhibitor) with respect to apo protein. Notably, four derivatives 5′-formylglabridin, glabridin dimer, 5′-prenyl glabridin and R-glabridin exhibited better binding affinity than glabridin. Glabridin effectively inhibited melanin production in a dose dependent manner. Among these, 5′-formylglabridin displayed highest binding affinity with docking score − 9.2 kcal/mol. Molecular properties and bioactivity analysis by Molinspiration web server and by SwissADME also presented these molecules as potential drug candidates. The study explores the understanding for the development of suitable tyrosinase inhibitor/s for the prevention of hyperpigmentation. However, a detailed in vivo study is required for glabridin derivatives to suggest these molecules as anti-melanogenic compound.

Plant-Derived Nanoscale-Encapsulated Antioxidants for Oral and Topical Uses: A Brief Review

Several plant-based nanoscale-encapsulated antioxidant compounds (rutin, myricetin, β-carotene, fisetin, lycopene, quercetin, genkwanin, lutein, resveratrol, eucalyptol, kaempferol, glabridin, pinene, and whole-plant bio-active compounds) are briefly introduced in this paper, along with their characteristics. Antioxidants’ bioavailability has become one of the main research topics in bio-nanomedicine. Two low patient compliance drug delivery pathways (namely, the oral and topical delivery routes), are described in detail in this paper, for nanoscale colloidal systems and gel formulations. Both routes and/or formulations seek to improve bioavailability and maximize the drug agents’ efficiency. Some well-known compounds have been robustly studied, but many remain elusive. The objective of this review is to discuss recent studies and advantages of nanoscale formulations of plant-derived antioxidant compounds.

Skullcapflavone II protects neuronal damage in cerebral ischemic rats via inhibiting NF-ĸB and promoting angiogenesis

BACKGROUND

Cerebral ischemia (CI) is considered as a main cause of cerebral stroke (CS) and poses significant risk to the mankind across the world. In the present study, we intended to investigate the protective effect of Skullcapflavone II (SCP) a flavonoid isolated from S. baicalensis on cerebral ischemia/reperfusion (I/R) injury.

METHODS

The middle cerebral artery occlusion (MCAO) and reperfusion was used to create ischemic stroke rat model. The rats were treated with (5, 10, and 15 mg/kg) SCP and after the end of the experiment the rats were sacrificed and various biochemical parameters were assed to determine the pharmacological action of SCP.

RESULTS

SCP dramatically decreases cerebral edema, infarct volume, and improves neurological manifestation as confirmed by reduced neurological deficit. SCP also improves the survivability of neurons as evidenced by H and E and Nissl staining. The level of oxidative stress in the cerebral cortex of the rats was found reduced after treatment with SCP, as confirmed by increase in GSH and SOD activity with reduction in MDA content. In addition, SCP attenuated inflammation via reducing the level of TNF-α, IL-1β and IL-6 in brain tissues of rats. SCP increases the expression of Bcl2, cleaved caspase-3 and -9, while decreasing Bax, and NF-ĸB/TLR4. It causes induction of angiogenesis as suggested by increased expression of VEGF, Ang-1 and Tie-2 in cerebral cortex of rat.

CONCLUSIONS

Our data determined that SCP may provide protective effect on the I/R-induced cerebral ischemia.

Anti-inflammatory Effects of a Novel Herbal Extract in the Muscle and Spinal Cord of an Amyotrophic Lateral Sclerosis Animal Model

Amyotrophic lateral sclerosis (ALS) is a complex disease characterized by motor neuron loss and muscle atrophy. There is no prominent treatment for ALS as the pathogenic process in the skeletal muscle and spinal cord is complex and multifactorial. Therefore, we investigated the effects of a herbal formula on the multi-target effects in the skeletal muscle and spinal cord in hSOD1G93A transgenic mice. We prepared a herbal extract (HE) from Glycyrrhiza uralensis, Atractylodes macrocephala Koidzumi, Panax ginseng, and Astragalus membranaceus. Control and HE-treated mice underwent rotarod and footprint tests. We also performed immunohistochemical and Western blotting analyses to assess expression of inflammation-related and oxidative stress-related proteins in the muscle and spinal cord tissues. We found that the HE increased motor activity and reduced motor neuron loss in hSOD1G93A mice. In addition, the HE significantly reduced the levels of inflammatory proteins and oxidative stress-related proteins in the skeletal muscles and spinal cord of hSOD1G93A mice. Furthermore, we demonstrated that the HE regulated autophagy function and augmented neuromuscular junction in the muscle of hSOD1G93A mice. Based on these results, we propose that the HE formula may be a potential therapeutic strategy for multi-target treatment in complex and multifactorial pathological diseases.

Leveraging hallmark Alzheimer's molecular targets using phytoconstituents: Current perspective and emerging trends

Alzheimer's disease (AD), a type of dementia, severely distresses different brain regions. Characterized by various neuropathologies, it interferes with cognitive functions and neuropsychiatrical controls. This progressive deterioration has negative impacts not only on an individual's daily activity but also on social and occupational life. The pharmacological approach has always remained in the limelight for the treatment of AD. However, this approach is condemned with several side effects. Henceforth, a change in treatment approach has become crucial. Plant-based natural products are garnering special attention due to lesser side effects associated with their use. The current review emphasizes the anti-AD properties of phytoconstituents, throws light on those under clinical trials, and compiles information on their specific mode of actions against AD-related different neuropathologies. The phytoconstituents alone or in combinations will surely help discover new potent drugs for the effective treatment of AD with lesser side effects than the currently available pharmacological treatment.

Glabridin ameliorates methotrexate-induced liver injury via attenuation of oxidative stress, inflammation, and apoptosis

Despite unprecedented advances in modern medicine, no safe and effective drug is available to date for oral administration to combat drug-induced liver injury, which is a vital concern nowadays. The present study deals with the hepatoprotective effect of pure glabridin, a key phytoconstituent from Glycyrrhiza glabra with mechanistic investigations using an in-vivo methotrexate-induced liver injury model as there is no such precedent. The study was performed in the Swiss mice model where a single dose of methotrexate (40 mg/kg) was given on the 7^th day through an intraperitoneal route to induce hepatotoxicity, and glabridin as a test compound was administered orally for eleven consecutive days at 10 to 40 mg/kg. Glabridin markedly improved serum biochemical parameters (SGPT, SGOT), proinflammatory cytokine (TNF-α) level, oxidative stress markers (MDA, GSH, SOD, CAT) as compared to methotrexate alone. Alterations in methotrexate-induced liver architecture were considerably prevented by glabridin treatment as suggested by liver histopathological examination and SEM investigation. Glabridin substantially prevented methotrexate-induced down-regulation of Nrf2, & activation of NF-κB, and caused up-regulation of BAX at different dose levels. Overall, glabridin is found to protect methotrexate-induced hepatotoxicity by improving important factors for oxidative stress, inflammation, and apoptosis.

Discovery and preclinical efficacy of HSG4112, a synthetic structural analog of glabridin, for the treatment of obesity

Background

HSG4112 is a clinical-stage drug candidate for the treatment of obesity. Here, we report its discovery and preclinical efficacy.

Methods

In high-fat diet (HFD)-induced obese male C57BL/6J mice, we tested the weight loss effect of synthetic compounds derived from a structure–activity relationship (SAR) study of glabridin, a natural compound known to reduce body weight and influence energy homeostasis. After selecting HSG4112 as our optimized compound from this discovery method, we characterized its pharmacological effects on parameters related to obesity through in vivo metabolic and biochemical measurements, histology and gene expression analysis, and indirect calorimetry.

Results

Through the SAR study, we identified four novel components of glabridin pertinent for its anti-obesity activity, and found that HSG4112, an optimized structural analog of glabridin, markedly supersedes glabridin in weight reduction efficacy and chemical stability. Six-week administration of HSG4112 to HFD-induced obese mice led to dose-dependent normalization of obesity-related parameters, including body weight, muscle and adipose tissue weight, adipocyte size, and serum leptin/insulin/glucose levels. The weight reduction induced by HSG4112 was partially mediated by decreased food intake and mainly mediated by increased energy expenditure, with no change in physical activity. Accordingly, the pattern of transcriptional changes was aligned with increased energy expenditure in the liver and muscles. Following significant body weight reduction, robust amelioration of histopathology and blood markers of fatty liver were also observed.

Conclusions

Our study demonstrates the key chemical components of glabridin pertinent to its weight loss effects and suggests HSG4112 as a promising novel drug candidate for the pharmacological treatment of obesity.

miR‑183‑5p attenuates cerebral ischemia injury by negatively regulating PTEN

Cerebral ischemia is a common cerebrovascular disease caused by the occlusion of a cerebral blood vessel. MicroRNAs (miRNAs/miRs) are emerging regulators of various human diseases, including cerebral ischemia. Upregulation of miR‑183‑5p has been reported to alleviate liver injury induced by ischemia‑reperfusion (I/R). However, the effect of miR‑183‑5p on cerebral ischemia injury remains unknown. The present study evaluated the effects of miR‑183‑5p on ischemia injury using ischemic models of mouse brains exposed to transient middle cerebral artery occlusion and Neuro‑2A (N2A) neuroblastoma cells exposed to oxygen‑glucose‑deprivation (OGD) and subsequently reoxygenated. Ischemia was evaluated in mice using neurological function scores, cerebral edema, 2,3,5‑triphenyltetrazoliumchloride, Nissl and Fluoro‑Jade B staining assays. In addition, miR‑183‑5p expression, N2A cell viability and the expression levels of apoptosis‑associated proteins were detected by quantitative PCR, Cell Counting Kit‑8 assay, flow cytometry and western blotting. The association between miR‑183‑5p and phosphatase and tensin homolog (PTEN) was also confirmed by a luciferase reporter assay. The results revealed that miR‑183‑5p expression was decreased and brain damage was increased in ischemic mice compared with the sham group. Additionally, miR‑183‑5p levels were reduced, and apoptosis was increased in N2A cells exposed to ischemia compared with the control group. Following transfection with agomiR‑183‑5p, cerebral ischemic injury and apoptosis levels were reduced in the in vivo I/R stroke model and OGD‑induced N2A cells. In addition, PTEN was determined to be a target of miR‑183‑5p following elucidation of a direct binding site. Overexpression of PTEN reversed the miR‑183‑5p‑induced N2A cell apoptosis inhibition and survival after OGD. The results of the present study suggested that miR‑183‑5p reduced ischemic injury by negatively regulating PTEN, which may aid the development of a novel therapeutic strategy for cerebral ischemia.

Efficacy of oral administration of licorice as an adjunct therapy on improving the symptoms of patients with Parkinson's disease, A randomized double blinded clinical trial

ETHNOPHARMACOLOGICAL RELEVANCE

Licorice preparations are used as neuroprotective remedies in Persian ethnomedicine, in order to prevent from disabilities in neurodegenerative conditions like Parkinson's disease (PD).

AIM OF THE STUDY

This study was designed to determine the licorice (root of Glycyrrhiza glabra L.) effectiveness as an adjunct treatment in the PD management.

MATERIAL AND METHODS

In this double-blinded trial, 128 patients were assessed for eligibility criteria. Seventy-eight patients were ineligible and 11 of them refused from participating. Thirty-nine PD patients (YAHR staging ≤ 3) were divided into two groups by random. The patients received oral licorice or placebo syrups with a dose of 5 cc, twice a day for 6 months. High-performance liquid chromatography and spectrophotometric instruments determined licorice syrup constituents. The patients' situation for Unified Parkinson's rating scale (UPDRS) was assessed every 6 weeks for the duration of six months. In addition, patients' blood pressure, blood glucose, sodium and potassium levels, quality of life and dizziness were determined.

RESULTS

Six weeks after intervention, total UPDRS, daily activities and tremor were significantly improved with a considerable effect size. A significant better motor test and rigidity scores were observed 4 months after licorice intake (p > 0.05). No electrolyte abnormality, significant changes in blood pressure or blood glucose levels were observed during the study. Each 5cc of syrup contained 136 mg of licorice extract with 12.14 mg glycyrrhizic acid, and also 136 μg of polyphenols.

CONCLUSION

The licorice intake could improve the symptoms in PD patients without serious adverse events.

Glycyrrhiza glabra L. (Fabaceae/Leguminosae)

Liquorice is a perennial, temperate-zone herb or subshrub, native of India, Pakistan and southern Europe; also cultivated in England, Belgium, France, Germany, Spain, Italy, Greece, Turkey, Russia, South Africa, Egypt, Syria and Iraq. It has also been grown experimentally in the United States. Ancient historical manuscripts from China, India and Greece mention its use for symptoms of viral respiratory tract infections and hepatitis. The plant has also been described by Theophrastus. Licorice from Egypt has been described to be the best, followed by from Iraq and Syria; the root should be decorticated before use. It concocts viscid humours in diseases of liver, bladder and lungs, and expectorates them. It has been used in Iranian herbal medicine for skin eruptions, including dermatitis, eczema, pruritus and cysts, and for treatment of stomach disorders including peptic ulcers. The herb extract inhibits gastric motility in vivo, which is regarded to be an important aspect for its antiulcer activity. Licorice possesses both anti-inflammatory and antiulcer activities; whereas most anti-inflammatory agents are ulcerogenic. Former German Commission E believed it to be effective in the treatment of atopic dermatitis. Licorice root has been used for years to regulate gastrointestinal function in TCM, has been used for generations as an antidote, demulcent, and elixir in folk medicine of China, and is the most commonly used crude drug in Kampo Medicines, the Japanese form of modified TCM, for the treatment of peptic ulcer. Roots contain glycyrrhizin, the main water-soluble constituent that is 50× sweeter than sugar, 2-β-glucuronosyl glucuronic acid, and isoliquiritigenin-4-glucoside. Glycyrrhizin is a nonhemolytic saponin with foaming property, and one of the most potent hydroxyl radical scavengers. No significant effect of deglycyrrhizinised liquorice was observed on gastric ulcer in an RCT of British patients. Treatment of healthy men with licorice for one-week decreased salivary testosterone values by 26% but no significant decrease in free testosterone, and nine healthy women treated with licorice daily for two cycles, had their mean total serum testosterone decreased by 37% at the end of 2nd month. This property could be useful as an adjunct therapy of hirsutism and PCOS.

In vitro antiproliferative activity of glabridin derivatives and their in silico target identification

Novel Mannich base derivatives of glabridin were synthesized and their antiproliferative activity were performed along with our previously reported glabridin-chalcone hybrids molecules (GCHMs) against various human cell lines MDA-MB-231 (breast adenocarcinoma), HEK-293 (embryonic kidney cell line), K562 (leukemia), MCF-7 (breast adenocarcinoma), HeLa (cervix adenocarcinoma), HepG2 (hepatocellular carcinoma) and WRL-68 (hepatic carcinoma). The result showed that the glabridin significantly reduced cell proliferation with IC₅₀ ranges from 3.67 to 58.30 µM against all the tested cell lines. The remarkable reduction in antiproliferative activity 2',4'-dimethoxyglabridin and GCHMs compounds with phenolic OH groups protected by methoxy (OCH₃) groups suggested that the free OH groups are essential factor for the antiproliferative activity of glabridin and its derivatives. The Mannich base derivatives of glabridin showed moderate activity IC₅₀ (2.20->95.78 µM). Furthermore, in silico target identification analysis revealed that AKT1, DECR1 and NOS1 are the potential targets for glabridin and their derivatives.

Protective effect of 6-O-methyl-scutellarein on repeated cerebral ischemia/reperfusion in rats

Scutellarin (1) possesses protective effects against neuronal injury, while 6-O-methyl-scutellarein (3), as the main metabolite of scutellarin in vivo, has not been reported about its protective effects previously. The present study mainly investigated whether the neural injury caused by ischemia/reperfusion would be influenced by different doses of 6-O-methyl-scutellarein (3). The results of behavioral, neurological, and histological examinations indicated that 6-O-methyl-scutellarein (3) could improve neuronal injury, and exhibit significant difference among the various doses. More importantly, 6-O-methyl-scutellarein (3) had better protective effects than scutellarin in rat cerebral ischemia.

β-Lactoglobulin as a Nanotransporter for Glabridin: Exploring the Binding Properties and Bioactivity Influences

Based on the fact that β-lactoglobulin (β-lg) can solubilize readily in water and bind many small hydrophobic molecules, a novel nanocomplexed glabridin with β-lg was developed by an antisolvent precipitation method. After binding to β-lg, the solubility of glabridin in aqueous solution was enhanced 21 times. Fluorescence spectroscopy of β-lg revealed that the interaction of glabridin with β-lg made the environment of Trp and Tyr residues on β-lg more hydrophilic. The morphology and crystal form of the nanocomplexed glabridin with β-lg was characterized and the changes in β-lg conformation was also been investigated. In combination with molecular docking modeling, the results revealed that glabridin was bound to β-lg by hydrophobic forces and hydrogen-bond interactions. Furthermore, the nanocomplexed glabridin with β-lg had a better 2,2-diphenyl-1-picrylhydrazyl radical-scavenging capacity and 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid radical-scavenging capacity compared to free glabridin at the same concentration during in vitro tests. Thus, nanocomplexing with β-lg, by virtue of its ability to enhance the solubility of glabridin in aqueous systems, provides a suitable opportunity as a nanocarrier molecule.

Glabridin induces apoptosis and cell cycle arrest in oral cancer cells through the JNK1/2 signaling pathway

Glabridin, a flavonoid extracted from licorice (Glycyrrhiza glabra), possesses various biological properties, including anticancer activities. However, the effect of glabridin on oral cancer cell apoptosis and the underlying molecular mechanisms has not been elucidated. In this study, we demonstrated that glabridin treatment significantly inhibits cell proliferation in human oral cancer SCC-9 and SAS cell lines. Flow cytometric assays demonstrated that glabridin induced several features of apoptosis, such as sub-G1 phase cell increase and phosphatidylserine externalization. Furthermore, glabridin induced apoptosis dose-dependently in SCC-9 cells through caspase-3, -8, and -9 activation and poly (ADP-ribose) polymerase cleavage. Moreover, glabridin increased the phosphorylation of the extracellular signal-regulated kinase, p38, and c-Jun N-terminal kinase (JNK) pathways in a dose-dependent manner. Moreover, the inhibition of the JNK1/2 inhibitor significantly reversed the glabridin-induced activation of the caspase pathway. In conclusion, our findings suggest that glabridin induces oral cancer cell apoptosis through the JNK1/2 pathway and is a potential therapeutic agent for oral cancer.

Glabridin inhibits the activation of myofibroblasts in human fibrotic buccal mucosal fibroblasts through TGF-β/smad signaling

Oral submucous fibrosis (OSF) has been recognized as one of the oral potentially malignant disorders. Areca nut chewing is implicated in this pathological fibrosis, and it causes chronic inflammation and persistent activation of myofibroblasts. As yet, existing treatments only provide temporary symptomatic relief and there is a lack of an effective intervention to cure OSF. Therefore, development of approaches to ameliorate myofibroblast activities becomes a crucial objective to prevent the malignant progression of OSF. In this study, we examined the inhibitory effect of glabridin, an isoflavane extracted from licorice root, on the myofibroblast characteristics in human fibrotic buccal mucosal fibroblasts (fBMFs). Our results showed that myofibroblast activities, including collagen gel contractility, migration, invasion and wound healing abilities were reduced after exposure of glabridin in a dose-dependent manner. Most importantly, we demonstrated that the arecoline-induced myofiroblast activities were abolished by glabridin treatment. Additionally, the expression of the myofibroblast marker α-smooth muscle actin and other fibrogenic marker, type I collagen, in fBMFs were dose-dependently downregulated. Moreover, we showed that the production of TGF-β was suppressed by glabridin in fBMFs and the protein expression of phospho-Smad2 was decreased as well. In summary, our data suggested that glabridin repressed the myofibroblast features in fBMFs via TGF-β/Smad2 signaling pathway. Glabridin also prevented the arecoline-increased myofibroblast activities, and could serve as a natural anti-fibrosis compound for OSF.

Glabridin attenuates lipopolysaccharide-induced acute lung injury by inhibiting p38MAPK/ERK signaling pathway

Background

Acute respiratory distress syndrome (ARDS) is a complication caused by pulmonary and/or external factors. In this study, we investigated the protective mechanisms of glabridin in lipopolysaccharide (LPS) induced ARDS in rats.

Results

GLA treatment at dose of 30 mg/kg decreased LPS-induced lung W/D ratio and alleviated evident lung histopathological changes. Expressions of TNF-α and IL-18 were suppressed by GLA in plasma. The levels of SPA, MDA and NO in lung were down-regulated significantly in groups administrated with GLA. While the SOD level increased after GLA administration. Additionally, the attenuation of inflammatory responses by GLA was closely associated with p38MAPK/ERK pathway, and the expressions of protein p-p38MAPK and pERK were inhibited by GLA in LPS-induced ARDS rats.

Materials and Methods

Sixty-four Wistar rats were randomly assigned into control group, Glabridin (GLA) alone group, LPS groups (6 h, 12 h, 24 h), GLA with LPS groups (6 h, 12 h, 24 h). ARDS was induced in rats by intraperitoneal administration of LPS (10 mg/kg). The degree of lung edema was evaluated by calculating the wet/dry weight ratio. The levels of inflammatory mediators, tumor necrosis factor-α (TNF-α) and interleukin-18 (IL-18) were assayed by enzyme-linked immunosorbent assay (ELISA). Surfactant protein A (SPA), malondialdehyde (MDA), nitric oxide (NO) and superoxide dismutase (SOD) were analyzed. Pathological changes of lung tissues were observed by H&E staining. The protein expression of p38MAPK and ERK was detected using immunohistochemical techniques. Lung phosphorylated p38MAPK (p-p38MAPK) and pERK protein expression changes were detected by Western blotting.

Conclusions

Glabridin significantly ameliorated the lung injury induced by LPS in rats via the inhibition of p38MAPK and ERK signaling pathway, antioxidant effect and reducing inflammation.

Protective effect of isoliquiritin against corticosterone-induced neurotoxicity in PC12 cells

Isoliquiritin, a flavonoid glycoside compound from licorice, possesses a broad spectrum of pharmacological activities including antioxidant, anti-inflammatory and anti-depression activities. However, the neuroprotective mechanisms of antidepressant effects remain unclear. In this study, the aim was to investigate the cytoprotective efficiency and potential mechanisms of isoliquiritin in corticosterone-damaged PC12 cells. The results of this study showed that pretreatment of PC12 cells with isoliquiritin significantly prevented corticosterone-induced cell apoptosis. In addition, isoliquiritin increased the activity of dismutase (SOD) and catalase (CAT), decreased the contents of reactive oxygen species (ROS) and malondialdehyde (MDA). These findings suggest that isoliquiritin provides protective action against corticosterone-induced cell damage by reducing oxidative stress. Furthermore, pretreatment with isoliquiritin reduced corticosterone-induced mitochondrial dysfunction by preventing mitochondrial membrane potential dissipation. Our findings indicate that isoliquiritin might exert its therapeutic effects via regulating mitochondrial dysfunction. Moreover, isoliquiritin strongly attenuated intracellular calcium ([Ca²⁺]i) overload and down-regulation of Bax, caspase-3 and cytochrome C (Cyt-C) protein expression, and up-regulation of Bcl protein expression. In conclusion, isoliquiritin has a cytoprotective effect on corticosterone-induced neurotoxicity in PC12 cells, which may be related to its antioxidant action, inhibition of [Ca²⁺]i overload and inhibition of the mitochondrial apoptotic pathway.

Glabridin Inhibits Migration, Invasion, and Angiogenesis of Human Non–Small Cell Lung Cancer A549 Cells by Inhibiting the FAK/Rho Signaling Pathway

This study reports the antimigration, anti-invasive effect of glabridin, a flavonoid obtained from licorice, in human non–small cell lung cancer A549 cells. Glabridin exhibited effective inhibition of cell metastasis by decreasing cancer cell migration and invasion of A549 cells. In addition, glabridin also decreased A549-mediated angiogenesis. Further investigation revealed that glabridin’s inhibition of cancer angiogenesis was also evident in a nude mice model. Blockade of A549 cells migration was associated with an increase of ανβ3 integrin proteosome degradation. Glabridin also decreased the active forms of FAK and Src, and enhanced levels of inactivated phosphorylated Src (Tyr 527), decreasing the interaction of FAK and Src. Inhibition of the FAK/Src complex by glabridin also blocked Akt activation, resulting in reduced activation of RhoA and myosin light chain phosphorylation. This study demonstrates that glabridin may be a novel anticancer agent for the treatment of lung cancer in 3 different ways: inhibition of migration, invasion, and angiogenesis.

Oleuropein Protects Cardiomyocyte against Apoptosis via Activating the Reperfusion Injury Salvage Kinase Pathway In Vitro

Oleuropein, the main glycoside present in olives, has been reported to have cardioprotective effect, but the exact mechanism has not been clearly elucidated. This study attempted to clarify the cardioprotective effect of oleuropein against simulated ischemia/reperfusion- (SI/R-) induced cardiomyocyte injury in vitro and further explore the underlying mechanism. Here we confirmed that oleuropein reduced the cell injury in neonatal rat cardiomyocyte induced by SI/R evidenced by decreasing MTT dye reduction and LDH activity in the culture medium. Meanwhile, the compound also inhibited reactive oxygen species excessive generation and stabilized mitochondrial membrane potential after SI/R. The flow cytometry assessment results indicated the inhibition of cellular apoptosis with oleuropein treatment. Furthermore, western blot analysis showed that oleuropein attenuated the expression of Cyt-C, c-caspase-3, and c-caspase-9, increased the Bcl-2/Bax ratio, and enhanced the phosphorylation of ERK1/2 and Akt after SI/R. However, the phosphorylation enhancement was partially abolished in the presence of LY294002 (PI3K inhibitor) and U0126 (ERK inhibitor). All these findings indicate that oleuropein has the protective potential against SI/R-induced injury and its protective effect may be partly due to the attenuation of apoptosis via the activation of the PI3K/Akt and ERK1/2 signaling pathways.

Neuroprotective effects of curdione against focal cerebral ischemia reperfusion injury in rats

BACKGROUND

Curdione is one of the most highly concentrated component of the active constituents in E-zhu, which has been reported to possess a variety of activities. However, the pharmacologic neuroprotective activity of curdione has not been evaluated. The present study aimed to investigate the protective effect of curdione on focal cerebral ischemia reperfusion-induced injury in rats and further exploring the underlying mechanisms.

MATERIALS AND METHODS

Adult male Sprague Dawley rats were subjected to middle cerebral artery occlusion (MCAO) surgery for 2 h, followed by reperfusion stage. All animals received treatment once a day for 7 days before surgery and 14 days from 4 h after the reperfusion started. The neurological deficit test and Morris water maze test were performed at 1, 4, 7 and 14 days after MCAO. The infarct size of animals was determined by the 2,3,5-triphenyltetrazolium chloride staining, and pathological brain damage was estimated by hematoxylin-eosin staining. The malonaldehyde (MDA) levels and the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-PX) were detected by enzyme-linked immunosorbent assay. Expression of apoptotic proteins was measured by Western blot.

RESULTS

Our results showed that curdione could significantly reduce the infarct size and neurological deficits, promote cognitive function recovery and recover neuronal morphologic damages in MCAO rats. It also blocked the increase of MDA content and elevated the activities of SOD, CAT and GSH-PX. Moreover, curdione attenuated the expression of Cyt-C, c-caspase-3 and c-caspase-9 increased the Bcl-2/Bax ratio and hence decreased the cellular apoptosis.

CONCLUSION

Curdione possessed potential neuroprotective effect on rats in the MCAO model. The anti-oxidative and anti-apoptotic properties may be involved in the underlying mechanisms.