Phytochemical and Pharmacological Role of Liquiritigenin and Isoliquiritigenin From Radix Glycyrrhizae in Human Health and Disease Models

Polyphenols as Plant-Based Nutraceuticals: Health Effects, Encapsulation, Nano-Delivery, and Application

Plant polyphenols have attracted considerable attention because of their key roles in preventing many diseases, including high blood sugar, high cholesterol, and cancer. A variety of functional foods have been designed and developed with plant polyphenols as the main active ingredients. Polyphenols mainly come from vegetables and fruits and can generally be divided according to their structure into flavonoids, astragalus, phenolic acids, and lignans. Polyphenols are a group of plant-derived functional food ingredients with different molecular structures and various biological activities including antioxidant, anti-inflammatory, and anticancer properties. However, many polyphenolic compounds have low oral bioavailability, which limits the application of polyphenols in nutraceuticals. Fortunately, green bio-based nanocarriers are well suited for encapsulating, protecting, and delivering polyphenols, thereby improving their bioavailability. In this paper, the health benefits of plant polyphenols in the prevention of various diseases are summarized, with a review of the research progress into bio-based nanocarriers for the improvement of the oral bioavailability of polyphenols. Polyphenols have great potential for application as key formulations in health and nutrition products. In the future, the development of food-grade delivery carriers for the encapsulation and delivery of polyphenolic compounds could well solve the limitations of poor water solubility and low bioavailability of polyphenols for practical applications.

Pharmacological activities and pharmacokinetics of liquiritin: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Liquiritin is a flavonoid derived from Radix et Rhizoma Glycyrrhizae, which is a widely used traditional Chinese medicine with the effects of invigorating spleen qi, clearing heat, resolving toxins, and dispelling phlegm to stop coughs.

AIM OF THE STUDY

In this review,the pharmacokinetics and pharmacological activities of liquiritin have been summarized.

MATERIALS AND METHODS

The information on liquiritin up to 2021 was collected from PubMed, Web of Science, Springer Link, and China National Knowledge Infrastructure databases. The key words were "liquiritin", "nerve", "tumor", "cardiac", etc. RESULTS: The absorption mechanism of liquiritin conforms to the passive diffusion and first-order kinetics while with low bioavailability. Liquiritin can penetrate the blood-brain-barrier. Besides, liquiritin displays numerous pharmacological effects including anti-Alzheimer's disease, antidepressant, antitumor, anti-inflammatory, cardiovascular protection, antitussive, hepatoprotection, and skin protective effects. In addition, the novel preparations, new pharmacological effects,and cdusafty of liquiritin are also discussed in this review.

CONCLUSION

This review provides a comprehensive state of knowledge on the pharmacokinetics and pharmacological activities of liquiritin, and makes a forecast for its research directions and applications in clinic.

Introducing a gatekeeping system for amyloid status assessment in mild cognitive impairment

Background

In patients with mild cognitive impairment (MCI), enhanced cerebral amyloid-β plaque burden is a high-risk factor to develop dementia with Alzheimer’s disease (AD). Not all patients have immediate access to the assessment of amyloid status (A-status) via gold standard methods. It may therefore be of interest to find suitable biomarkers to preselect patients benefitting most from additional workup of the A-status. In this study, we propose a machine learning–based gatekeeping system for the prediction of A-status on the grounds of pre-existing information on APOE-genotype ¹⁸F-FDG PET, age, and sex.

Methods

Three hundred and forty-two MCI patients were used to train different machine learning classifiers to predict A-status majority classes among APOE-ε4 non-carriers (APOE4-nc; majority class: amyloid negative (Aβ-)) and carriers (APOE4-c; majority class: amyloid positive (Aβ +)) from ¹⁸F-FDG-PET, age, and sex. Classifiers were tested on two different datasets. Finally, frequencies of progression to dementia were compared between gold standard and predicted A-status.

Results

Aβ- in APOE4-nc and Aβ + in APOE4-c were predicted with a precision of 87% and a recall of 79% and 51%, respectively. Predicted A-status and gold standard A-status were at least equally indicative of risk of progression to dementia.

Conclusion

We developed an algorithm allowing approximation of A-status in MCI with good reliability using APOE-genotype, ¹⁸F-FDG PET, age, and sex information. The algorithm could enable better estimation of individual risk for developing AD based on existing biomarker information, and support efficient selection of patients who would benefit most from further etiological clarification. Further potential utility in clinical routine and clinical trials is discussed.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00259-022-05879-6.

Liquiritin Attenuates Pathological Cardiac Hypertrophy by Activating the PKA/LKB1/AMPK Pathway

Background: Liquiritin (LQ) is one of the main flavonoids extracted from the roots of Glycyrrhiza spp., which are widely used in traditional Chinese medicine. Studies in both cellular and animal disease models have shown that LQ attenuates or prevents oxidative stress, inflammation, and apoptosis. However, the potential therapeutic effects of LQ on pressure overload-induced cardiac hypertrophy have not been so far explored. Therefore, we investigated the cardioprotective role of LQ and its underlying mechanisms in the aortic banding (AB)-induced cardiac hypertrophy mouse model.

Methods and Results: Starting 3 days after AB surgery, LQ (80 mg/kg/day) was administered daily over 4 weeks. Echocardiography and pressure-volume loop analysis indicated that LQ treatment markedly improved hypertrophy-related cardiac dysfunction. Moreover, hematoxylin and eosin, picrosirius red, and TUNEL staining showed that LQ significantly inhibited cardiomyocyte hypertrophy, interstitial fibrosis, and apoptosis. Western blot assays further showed that LQ activated LKB1/AMPKα2/ACC signaling and inhibited mTORC1 phosphorylation in cardiomyocytes. Notably, LQ treatment failed to prevent cardiac dysfunction, hypertrophy, and fibrosis in AMPKα2 knockout (AMPKα2^−/−) mice. However, LQ still induced LKB1 phosphorylation in AMPKα2^−/− mouse hearts. In vitro experiments further demonstrated that LQ inhibited Ang II-induced hypertrophy in neonatal rat cardiomyocytes (NRCMs) by increasing cAMP levels and PKA activity. Supporting the central involvement of the cAMP/PKA/LKB1/AMPKα2 signaling pathway in the cardioprotective effects of LQ, inhibition of Ang II-induced hypertrophy and induction of LKB1 and AMPKα phosphorylation were no longer observed after inhibiting PKA activity.

Conclusion: This study revealed that LQ alleviates pressure overload-induced cardiac hypertrophy in vivo and inhibits Ang II-induced cardiomyocyte hypertrophy in vitro via activating cAMP/PKA/LKB1/AMPKα2 signaling. These findings suggest that LQ might be a valuable adjunct to therapeutic approaches for treating pathological cardiac remodeling.

Toxicity, Antioxidant Activity, and Phytochemicals of Basil (Ocimum basilicum L.) Leaves Cultivated in Southern Punjab, Pakistan

Basil (Ocimum basilicum L.) is one of the most common aromatic herbs, a rich source of bioactive compounds, and is used extensively to add aroma and flavor to food. The leaves, both in fresh and dried form, are used as a culinary ingredient in different cultures. O. basilicum is also famous for its therapeutic potential and preservation effects. The present study investigated the cytotoxicity of basil at three different growth stages (GS), i.e., GS-1 (58 days of growth), GS-2 (69 days of growth), and GS-3 (93 days of growth) using the brine shrimp lethality assay. The results revealed that cytotoxicity was influenced by GS and the concentration of extracts. Aqueous extracts of basil at a concentration of 10 to 1000 µg/mL did not show notable toxicity. The lowest mortality rate, i.e., 8.9%, was recorded for GS-2 at the highest tested dose of basil extracts. The mortality rate at GS-1, GS-2, and GS-3 was found to be 26.7 ± 3.34%, 8.91 ± 0.10%, and 16.7 ± 0.34%, respectively, at 1000 µg/mL. GS-2 basil powder with the lowest toxicological risk was extracted with different solvents, viz., n-hexane, dichloromethane, ethanol, and water. The highest concentration of plant secondary metabolites including total phenolic acid, flavonoids, and tannin content was observed in ethanol extracts. Ethanol extracts also exhibited the highest antioxidant activity in DPPH, FRAP and H₂O₂ assays. LC-ESI-MS/MS analysis presented ethanol extracts of basil as a promising source of known health-promoting and therapeutic compounds such as rosmarinic acid, ellagic acid, catechin, liquiritigenin, and umbelliferone. The results suggest basil, a culinary ingredient, as a potential source of bioactive compounds which may offer an array of health promoting and therapeutic properties.

Wen Dan Tang: A Potential Jing Fang Decoction for Headache Disorders?

BACKGROUND

Chinese herbal medicine is considered relatively safe, inexpensive, and easily accessible. Wen Dan Tang (WDT), a Jing Fang ancient classical Chinese herbal formula with a broad indication profile has been used for several centuries in China to treat various illnesses.

QUESTION

Are there evidence-based clinical trials that show that WDT has a significant impact on the treatment of various diseases, especially in patients with migraine and tension-type headaches (TTH)?

METHODS

This study is based on an online database search using PubMed, Medline, Cochrane Library, AcuTrials, Embase, Semantic Scholar, Jstor, internet research, and review of ancient and modern Chinese medical textbooks regarding WDT and its compounds.

RESULTS

There were no studies on WDT in migraine and TTH; therefore, this work gathers and describes data for every single compound in the formula.

CONCLUSION

This study suggests that the bioactive compounds found in WDT composition show potential in treating patients with neurological, psychiatric disorders, cardiovascular diseases, metabolic syndrome, and digestive disorders. Some coherence between WDT in headache reduction and improvements in the quality of life in patients with migraines and TTH could be evaluated, showing positive results of WDT in these patients.

Antioxidative role of Traditional Chinese Medicine in Parkinson's disease

ETHNOPHARMACOLOGICAL RELEVANCE

Neuroprotective Traditional Chinese Medicine (TCM) has been practiced in alternative medicine from early days. TCM-derived neuroprotective compounds, such as Chrysin, Cannabidiol, Toonasinoids, and β-asaron, exert significant effectiveness's towards Parkinson's disease (PD). Further, these neuroprotective TCM showed antioxidative, anti-inflammatory, anti-tumor, anti-septic, analgesic properties. Recent research showed that the reduction in the reactive oxygen species (ROS) decreased the α-synuclein (α-syn) toxicity and enhanced the dopaminergic neuron regenerations, the main hallmarks of PD. Therefore, the neuroprotective effects of novel TCM due to its antiradical activities needed deep investigations.

AIMS OF THE STUDY

This review aims to enlighten the neuroprotective TCM and its components with their antioxidative properties to the scientific community for future research.

METHOD

The relevant information on the neuroprotective TCM was gathered from scientific databases (PubMed, Web of Science, Google Scholar, ScienceDirect, SciFinder, Wiley Online Library, ACS Publications, and CNKI). Information was also gained from MS and Ph.D. thesis, books, and online databases. The literature cited in this review dates from 2001 to June 2, 0201.

RESULTS

Novel therapies for PD are accessible, mostly rely on Rivastigmine and Donepezil, offers to slow down the progression of disease at an early stage but embraces lots of disadvantages. Researchers are trying to find a potential drug against PD, which is proficient at preventing or curing the disease progress, but still needed to be further identified. Oxidative insult and mitochondrial dysfunction are thought to be the main culprit of neurodegenerations. Reactive oxygen species (ROS) are the only causative agent in all interactions, leading to PD, from mitochondrial dysfunctions, α-syn aggregative toxicity, and DA neurons degenerations. It is evident from the redox balance, which seems an imperative therapeutic approach against PD and was necessary for the significant neuronal activities.

CONCLUSION

Our study is explaining the newly discovered TCM and their neuroprotective and antioxidative properties. But also bring up the possible treatment approaches against PD for future researchers.

Jin-Wu-Jian-Gu Formulation Attenuates Rheumatoid Arthritis by Inhibiting the IL33-ST2 Signaling Pathway

The present research attempted to investigate the molecular mechanism of Jin-Wu-Jian-Gu Formulation (JWJGF) in inhibiting rheumatoid arthritis (RA) in a pharmacological approach for analysis and experimental validation. First, the potential targets and pathways of JWJGF for RA were predicted by network pharmacology. Second, the effect of JWJGF on RA was observed by hematoxylin-eosin (HE) staining and enzyme-linked immunosorbent assay (ELISA). Further, we observed the effects of JWJGF on the IL33-ST2 signaling pathway by Western blot and quantitative real-time PCR (qPCR) experiments, and finally, we studied the effects of Liquiritigenin on rheumatoid arthritis synovial fibroblast (RASF) cells and the IL33-ST2 signaling pathway. Network pharmacology results showed that the key component of JWJGF was Liquiritigenin and the core target of JWJGF was IL-33. The results of HE and ELISA showed that JWJGF could alleviate RA. Western blot and qPCR findings indicated that JWJGF could inhibit the IL33-ST2 signaling pathway. Furthermore, JWJGF could inhibit the proliferation of RASF cells and the IL33-ST2 signaling pathway. In conclusion, this study revealed that JWJGF attenuated RA by inhibiting the IL33-ST2 signaling pathway.

Isoliquiritigenin attenuates neuroinflammation in mice model of Parkinson's disease by promoting Nrf2/NQO-1 pathway

Parkinson's disease (PD) is a common neurodegenerative disease that severely affects the quality of life of patients. There is no specific drug for PD up to now. Previous studies have shown that neuroinflammation plays an important role in the pathogenesis of PD. Isoliquiritigenin (ILG) is thought to have a variety of biological activities including anti-inflammatory. However, to date, no studies have reported the role of ILG on neuroinflammation in PD in vivo. This study aimed to investigate the effect of ILG on PD in vivo and its mechanism, and to provide an experimental basis for clinical treatment of PD. Our results showed that ILG at a concentration of 20 mg/kg was effective in reducing the number of rotations in PD mice. In addition, ILG increased the expression of tyrosine hydroxylase and decreased the expression of α-synuclein. The results also showed that ILG reduced the expression of Iba1, IL-1β, IL-6, and TNF-α. Not only that, ILG also upregulated the expression of Nrf2 and NQO-1 in vivo. Our results suggest that ILG significantly attenuates neurological deficits in PD, and the mechanism may be through the activation of the Nrf2/NQO-1 signaling pathway to reduce neuroinflammation. Moreover, our findings provide a new therapeutic strategy for PD.

Liquiritigenin enhances cyclic adenosine monophosphate production to mitigate inflammation in dendritic cells

Objective: This study aims to dissect the mechanism of traditional Chinese medicinal herbs against asthma; we chose to first focus on the main chemical components of licorice to investigate their contribution to asthmatic inflammation inhibition. Methods: Production of cellular nucleotide molecules such as cAMP, cGMP, and cGAMP was examined by using enzyme-linked immunosorbent assay (ELISA). Enzyme-encoding genes were tested in vitro using quantitative real-time PCR and protein level was detected by Western blotting analysis. In addition, co-culturing of murine dendritic cells together with T cells was conducted to examine the expression of cytokine genes and host immune response. Results: We found that one of the components within licorice, named liquiritigenin (LR), could efficiently enhance cAMP production in different cell lines. The augmentation of such molecules was linked to the high expression of cAMP synthesis genes and repressed expression of cAMP breaking down genes. In addition, the downstream immune response was also alleviated by the increase in cAMP levels by LR, suggesting the great potential of this molecule against inflammation. Subsequent immunological tests showed that LR could efficiently inhibit the expression of several cytokines and alter the NF-κB pathway and T cell polarization. Conclusion: Altogether, we have identified a promising antiasthmatic agent LR that could exhibit immunosuppressive function by elevating the cAMP level.

Isoliquiritigenin, a potent human monoamine oxidase inhibitor, modulates dopamine D1, D3, and vasopressin V1A receptors

Isoliquiritigenin (= 4,2′,4′-Trihydroxychalcone) (ILG) is a major constituent of the Glycyrrhizae Rhizoma that has significant neuroprotective functions. In the present study, we re-examined the potential of ILG to inhibit human monoamine oxidase (hMAO) in vitro and established its mechanism of inhibition through a kinetics study and molecular docking examination. ILG showed competitive inhibition of hMAO-A and mixed inhibition of hMAO-B with IC₅₀ values of 0.68 and 0.33 µM, respectively, which varied slightly from the reported IC₅₀ values. Since ILG has been reported to reduce dopaminergic neurodegeneration and psychostimulant-induced toxicity (both of which are related to dopamine and vasopressin receptors), we investigated the binding affinity and modulatory functions of ILG on dopamine and vasopressin receptors. ILG was explored as an antagonist of the D₁ receptor and an agonist of the D₃ and V_1A receptors with good potency. An in silico docking investigation revealed that ILG can interact with active site residues at target receptors with low binding energies. These activities of ILG on hMAO and brain receptors suggest the potential role of the compound to ameliorate dopaminergic deficits, depression, anxiety, and associated symptoms in Parkinson’s disease and other neuronal disorders.

Pharmacokinetics-based identification of pseudoaldosterogenic compounds originating from Glycyrrhiza uralensis roots (Gancao) after dosing LianhuaQingwen capsule

LianhuaQingwen capsule, prepared from an herbal combination, is officially recommended as treatment for COVID-19 in China. Of the serial pharmacokinetic investigations we designed to facilitate identifying LianhuaQingwen compounds that are likely to be therapeutically important, the current investigation focused on the component Glycyrrhiza uralensis roots (Gancao). Besides its function in COVID-19 treatment, Gancao is able to induce pseudoaldosteronism by inhibiting renal 11β-HSD2. Systemic and colon-luminal exposure to Gancao compounds were characterized in volunteers receiving LianhuaQingwen and by in vitro metabolism studies. Access of Gancao compounds to 11β-HSD2 was characterized using human/rat, in vitro transport, and plasma protein binding studies, while 11β-HSD2 inhibition was assessed using human kidney microsomes. LianhuaQingwen contained a total of 41 Gancao constituents (0.01-8.56 μmol/day). Although glycyrrhizin (1), licorice saponin G2 (2), and liquiritin/liquiritin apioside (21/22) were the major Gancao constituents in LianhuaQingwen, their poor intestinal absorption and access to colonic microbiota resulted in significant levels of their respective deglycosylated metabolites glycyrrhetic acid (8), 24-hydroxyglycyrrhetic acid (M2D; a new Gancao metabolite), and liquiritigenin (27) in human plasma and feces after dosing. These circulating metabolites were glucuronized/sulfated in the liver and then excreted into bile. Hepatic oxidation of 8 also yielded M2D. Circulating 8 and M2D, having good membrane permeability, could access (via passive tubular reabsorption) and inhibit renal 11β-HSD2. Collectively, 1 and 2 were metabolically activated to the pseudoaldosterogenic compounds 8 and M2D. This investigation, together with such investigations of other components, has implications for precisely defining therapeutic benefit of LianhuaQingwen and conditions for its safe use.

Targeting Mitochondria by Plant Secondary Metabolites: A Promising Strategy in Combating Parkinson's Disease

Parkinson’s disease (PD) is one of the most prevalent and debilitating neurodegenerative conditions, and is currently on the rise. Several dysregulated pathways are behind the pathogenesis of PD; however, the critical targets remain unclear. Accordingly, there is an urgent need to reveal the key dysregulated pathways in PD. Prevailing reports have highlighted the importance of mitochondrial and cross-talked mediators in neurological disorders, genetic changes, and related complications of PD. Multiple pathophysiological mechanisms of PD, as well as the low efficacy and side effects of conventional neuroprotective therapies, drive the need for finding novel alternative agents. Recently, much attention has been paid to using plant secondary metabolites (e.g., flavonoids/phenolic compounds, alkaloids, and terpenoids) in the modulation of PD-associated manifestations by targeting mitochondria. In this line, plant secondary metabolites have shown promising potential for the simultaneous modulation of mitochondrial apoptosis and reactive oxygen species. This review aimed to address mitochondria and multiple dysregulated pathways in PD by plant-derived secondary metabolites.

Isoliquiritigenin Alleviates Semen Strychni-Induced Neurotoxicity by Restoring the Metabolic Pathway of Neurotransmitters in Rats

Acute neurotoxicity of Semen Strychni can result in sudden death in epilepsy. The detoxification method and mechanism of Semen Strychni acute poisoning have not been clarified. This experiment focused on the mechanism of Semen Strychni neurotoxicity and the alleviation effects of isoliquiritigenin. The rats were intraperitoneally injected with Semen Strychni extract (125 mg/kg), followed by oral administration of isoliquiritigenin (50 mg/kg) for 7 days. FJ-B staining was used to evaluate the degree of injury on hippocampus neurons. The concentration of monoamines, amino acids, and choline neurotransmitters, the Dopamine (DA) and 5-hydroxytryptamine (5-HT) metabolic pathway in the hippocampus, cerebellum, striatum, prefrontal cortex, hypothalamus, serum, and plasma were detected by LC-MS/MS. The expression of neurotransmitter metabolic enzymes [catechol-O-methyl transferase (COMT) and monoamine oxidase (MAO)] and neurotransmitter receptors [glutamate N-methyl-D-aspartic acid receptors (NMDARs) and gamma-aminobutyric acid type A receptor (GABRs)] were, respectively determined using ELISA and qRT-PCR. The results indicated that Semen Strychni induced neuronal degeneration in the hippocampal CA1 region. Meanwhile, Semen Strychni inhibited the mRNA expression of NMDAR1, NMDAR2A, NMDAR2B, GABRa1, GABRb2 and reduced the level of MAO, which disrupted the DA and 5-HT metabolic pathway. However, isoliquiritigenin reversed these effects. In summary, isoliquiritigenin showed alleviation effects on Semen Strychni-induced neurotoxicity, which could be attributed to restoring neurotransmitters metabolic pathway, most likely through the activation of NMDA receptors.

Design, synthesis, and cholinesterase inhibition assay of liquiritigenin derivatives as anti-Alzheimer's activity

The marine environment is a rich resource for discovering functional materials, and seaweed is recognized for its potential use in biology and medicine. Liquiritigenin has been isolated and identified from Sargassum pallidum. To find new anti-Alzheimer's activity, we designed and synthesized thirty-two 7-prenyloxy-2,3-dihydroflavanone derivatives (3a-3p) and 5-hydroxy-7-prenyloxy-2,3-dihydro-flavanone derivatives (4a-4p) as cholinesterases inhibitors based on liquiritigenin as the lead compound. Inhibition screening against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) indicated that all synthesized compounds possessed potent AChE inhibitory activity and moderated to weak BuChE inhibitory activity in vitro. Kinetic studies demonstrated that compound 4o inhibited AChE via a dual binding site ability. In addition, all compounds displayed the radical scavenging effects. Finally, the molecular docking simulation of 4o in AChE active site displayed good agreement with the obtained the pharmacological results.

Natural Product Isoliquiritigenin Activates GABAB Receptors to Decrease Voltage-Gate Ca2+ Channels and Glutamate Release in Rat Cerebrocortical Nerve Terminals

Reduction in glutamate release is a key mechanism for neuroprotection and we investigated the effect of isoliquiritigenin (ISL), an active ingredient of Glycyrrhiza with neuroprotective activities, on glutamate release in rat cerebrocortical nerve terminals (synaptosomes). ISL produced a concentration-dependent inhibition of glutamate release and reduced the intraterminal [Ca²⁺] increase. The inhibition of glutamate release by ISL was prevented after removing extracellular Ca²⁺ or blocking P/Q-type Ca²⁺ channels. This inhibition was mediated through the γ-aminobutyric acid type B (GABA_B) receptors because ISL was unable to inhibit glutamate release in the presence of baclofen (an GABA_B agonist) or CGP3548 (an GABA_B antagonist) and docking data revealed that ISL interacted with GABA_B receptors. Furthermore, the ISL inhibition of glutamate release was abolished through the inhibition of G_i/o-mediated responses or G_βγ subunits, but not by 8-bromoadenosine 3′,5′-cyclic monophosphate or adenylate cyclase inhibition. The ISL inhibition of glutamate release was also abolished through the inhibition of protein kinase C (PKC), and ISL decreased the phosphorylation of PKC. Thus, we inferred that ISL, through GABA_B receptor activation and G_βγ-coupled inhibition of P/Q-type Ca²⁺ channels, suppressed the PKC phosphorylation to cause a decrease in evoked glutamate release at rat cerebrocortical nerve terminals.

Inflammation suppression in doxorubicin-induced cardiotoxicity: natural compounds as therapeutic options

Doxorubicin (DOX) is a potent chemotherapeutic agent; however, the accompanying cardiotoxicity is a significant complication of the usefulness of treatment with DOX. Multiple mechanisms have been suggested for this often fatal side effect, one of which is inflammation. Several pathways with different targets have been reported to result in DOX-induced heart inflammation. Some natural occurring compounds (NCs) have been reported to interact with the DOX-induced cardiotoxicity through targeting one or more of several pathways, including the Nrf2/NF-kB, TLR-4/NF-kB, MAPK/NF-kB, and NLRP3 inflammasome pathways. This article reviews several of these pathways and the potential protective effect of some NCs against the cardiac inflammation induced by DOX.

The State of The Art on Acetylcholinesterase Inhibitors in the Treatment of Alzheimer's Disease

Alzheimer's disease (AD) is a chronic disabling disease that affects the central nervous system. The main consequences of AD include the decline of cognitive functions and language disorders. One of the causes leading to AD is the decrease of neurotransmitter acetylcholine (ACh) levels in the brain, in part due to a higher activity of acetylcholinesterase (AChE), the enzyme responsible for its degradation. Many acetylcholinesterase inhibitors (AChEIs), both natural and synthetic, have been developed and used through the years to counteract the progression of the disease. The first of such drugs approved for a therapeutic use was tacrine, that binds through a reversible bond to the enzyme. However, tacrine has since been withdrawn because of its adverse effects. Currently, donepezil and galantamine are very promising AChEIs with clinical benefits. Moreover, rivastigmine is considered a pseudo-irreversible compound with anti-AChE action, providing similar effects at the clinical level. The purpose of this review is to provide an overview of what has been published over the last decade on the effectiveness of AChEIs in AD, analysing the most relevant issues under the clinical and methodological profiles and the consequent possible welfare effects for the whole world. Furthermore, novel drugs and possible therapeutic approaches are also discussed.

Flavonoids as Promising Antiviral Agents against SARS-CoV-2 Infection: A Mechanistic Review

A newly diagnosed coronavirus in 2019 (COVID-19) has affected all human activities since its discovery. Flavonoids commonly found in the human diet have attracted a lot of attention due to their remarkable biological activities. This paper provides a comprehensive review of the benefits of flavonoids in COVID-19 disease. Previously-reported effects of flavonoids on five RNA viruses with similar clinical manifestations and/or pharmacological treatments, including influenza, human immunodeficiency virus (HIV), severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and Ebola, were considered. Flavonoids act via direct antiviral properties, where they inhibit different stages of the virus infective cycle and indirect effects when they modulate host responses to viral infection and subsequent complications. Flavonoids have shown antiviral activity via inhibition of viral protease, RNA polymerase, and mRNA, virus replication, and infectivity. The compounds were also effective for the regulation of interferons, pro-inflammatory cytokines, and sub-cellular inflammatory pathways such as nuclear factor-κB and Jun N-terminal kinases. Baicalin, quercetin and its derivatives, hesperidin, and catechins are the most studied flavonoids in this regard. In conclusion, dietary flavonoids are promising treatment options against COVID-19 infection; however, future investigations are recommended to assess the antiviral properties of these compounds on this disease.

Phytochemicals as Regulators of Genes Involved in Synucleinopathies

Synucleinopathies are a group of neurodegenerative diseases characterized by the accumulation of α-synuclein aggregates in neurons, nerve fibers or glial cells. Three main types of diseases belong to the synucleinopathies: Parkinson’s disease, dementia with Lewy bodies, and multiple system atrophy. All of them develop as a result of an interplay of genetic and environmental factors. Emerging evidence suggests that epigenetic mechanisms play an essential role in the development of synucleinopathies. Since there is no disease-modifying treatment for these disorders at this time, interest is growing in plant-derived chemicals as a potential treatment option. Phytochemicals are substances of plant origin that possess biological activity, which might have effects on human health. Phytochemicals with neuroprotective activity target different elements in pathogenic pathways due to their antioxidants, anti-inflammatory, and antiapoptotic properties, and ability to reduce cellular stress. Multiple recent studies demonstrate that the beneficial effects of phytochemicals may be explained by their ability to modulate the expression of genes implicated in synucleinopathies and other diseases. These substances may regulate transcription directly via transcription factors (TFs) or play the role of epigenetic regulators through their effect on histone modification, DNA methylation, and RNA-based mechanisms. Here, we summarize new data about the impact of phytochemicals on the pathogenesis of synucleinopathies through regulation of gene expression.

The Calcium-Activated Chloride Channel TMEM16A is Inhibitied by Liquiritigenin

The transmembrane 16 (TMEM16) family contains 10 subtypes, and the function of each protein is different. TMEM16A is a calcium-activated chloride channel involved in physiological and pathological situations. Liquiritigenin is an aglycone derived from Glycyrrhiza glabra, and it is generated via the metabolism of enterobacterial flora. It has been known that liquiritigenin reduces pain sensation involving TMEM16A activation in primary sensory neurons. In addition, other pharmacological effects of liquiritigenin in physiological functions involving TMEM16A have been reported. However, the relationship between TMEM16A and liquiritigenin is still unknown. Therefore, we hypothesized that TMEM16A is inhibited by liquiritigenin. To confirm this hypothesis, we investigated the effect of liquiritigenin on TMEM16A currents evoked by intracellular free calcium in HEK293T cells transfected with TMEM16A. In this study, we found that liquiritigenin inhibited the mouse and human TMEM16A currents. To further confirm its selectivity, we also investigated its pharmacological effects on other ion channels, including transient receptor potential vanilloid 1 (TRPV1) and ankyrin 1 (TRPA1), which are non-selective cation channels involved in pain sensation. However, liquiritigenin did not inhibit the currents of TRPV1 and TRPA1 induced by capsaicin and allyl isothiocyanate, respectively. Therefore, our findings indicate that selective TMEM16A inhibition could be one molecular mechanism that explains liquiritigenin-induced pain reduction. Additionally, we also investigated the inhibitory effects of estrogens on TMEM16A because liquiritigenin reportedly binds to the estrogen receptor. In this study, a pregnancy-dependent estrogen, estriol, significantly inhibited TMEM16A. However, the efficacy was weak. Although there is a possibility that TMEM16A activity could be suppressed during pregnancy, the physiological significance seems to be small. Thus, the inhibitory effect of estrogen might not be significant under physiological conditions. Furthermore, we investigated the effect of dihydrodaidzein, which is an analog of liquiritigenin that has a hydroxyphenyl at different carbon atom of pyranose. Dihydrodaidzein also inhibited mouse and human TMEM16A. However, the inhibitory effects were weaker than those of liquiritigenin. This suggests that the efficacy of TMEM16A antagonists depends on the hydroxyl group positions. Our finding of liquiritigenin-dependent TMEM16A inhibition could connect the current fragmented knowledge of the physiological and pathological mechanisms involving TMEM16A and liquiritigenin.

Effectiveness of the Natural Antioxidant 2,4,4'-Trihydroxychalcone on the Oxidation of Sunflower Oil during Storage

This study aimed to investigate the effectiveness of 2,4,4′-trihydroxychalcone as a natural antioxidant on the oxidation of sunflower oil during an 88-day storage period and to compare its strength with the synthetic antioxidant butylated hydroxytoluene (BHT). Seven groups of the sunflower oil samples were prepared: pure oil (control), oil treated with different concentrations (100, 500, and 1000 ppm) of 2,4,4′-trihydroxychalcone, and oil treated with different concentrations (100, 500, and 1000 ppm) of BHT. Specific parameters, namely, the peroxide value (PV), acid value (AV), p-anisidine value (p-AnV), thiobarbituric acid reactive substance (TBARS) value and total oxidation (TOTOX) value were used to assess the extent of the deterioration of the oil by estimating the primary and secondary oxidation products. The results showed that 2,4,4′-trihydroxychalcone effectively decreased the production of the primary and secondary oxidation products of sunflower oil during storage, as indicated by reductions in the PVs, AVs, p-AnVs, TBARS values and TOTOX values of the sunflower oil. When compared to BHT, 2,4,4′-trihydroxychalcone showed either a similar or stronger effect in inhibiting the primary and secondary oxidation products. These findings suggest that, 2,4,4′-trihydroxychalcone is a suitable natural alternative to synthetic antioxidants to improve the oxidative stability of sunflower oil.

Isoliquiritigenin attenuates inflammation and modulates Nrf2/caspase-3 signalling in STZ-induced aortic injury

OBJECTIVES

The current study provides evidence on the ameliorative impact of Isoliquiritigenin (ISL), a natural bioflavonoid isolated from licorice roots against diabetes mellitus (DM)-induced aortic injury in rats.

METHODS

DM was induced in male Sprague-Dawley rats by single I.P. injection of STZ (50 mg/kg). ISL was administrated daily (20 mg/kg, orally) for 8 wks.

KEY FINDINGS

Diabetic group showed a significant aortic injury with evidence of atherosclerotic lesions development. Daily ISL (20 mg/kg, orally) administration for 8 wks significantly restored aortic oxidative/antioxidative stress homeostasis via modulating NrF-2/Keap-1/HO-1. Moreover, ISL treatment restored aortic levels of IL-10 and dampened aortic levels of IL-6 and TNF-α. Caspase-3 expression significantly declined as well. Further, ISL treatment successfully suppressed aortic endothelin-1 (ET-1) expression and restored NO contents, eNOS immunostaining paralleled with retraction in atherosclerotic lesions development, and lipid deposition with histopathological architectural preservation and restoration of almost normal aortic thickness.

CONCLUSION

ISL can be proposed to be an effective protective therapy to prevent progression of DM-induced vascular injury and to preserve aortic integrity.

Prospective: Evolution of Chinese Medicine to Treat COVID-19 Patients in China

During the outbreak of the novel coronavirus disease (COVID-19), the Chinese government took a series of public health measures to tackle the outbreak and recommended six traditional Chinese medicine (TCM) evolved formulas, collectively referred to as "3-drugs-3-formulas", for the treatment. In this prospective article, we will discuss how these six formulas evolved from TCM and what their underlying mechanisms of actions may be by evaluating the historical usage of the component formulas, the potential targeted pathways for the individual herbs used by STAR (signal transduction activity response) database from our laboratory, and the pathogenesis of COVID-19. Five of the six recommended formulas are administered orally, while the sixth is taken as an injection. Five classic categories of herbs in the six formulas including "Qing-Re", "Qu-Shi", "Huo-Xue", "Bu-Yi" and "Xing-Qi" herbs are used based on different stages of disease. All five oral formulas build upon the core formula Maxingshigan Decoction (MD) which has anti-inflammatory and perhaps antiviral actions. While MD can have some desired effects, it may not be sufficient to treat COVID-19 on its own; consequently, complementary classic formulas and/or herbs have been added to potentiate each recommended formula's anti-inflammatory, and perhaps anti-renin-angiotensin system (RAS)-mediated bradykinin storm (RBS) and antiviral effects to address the unique medical needs for different stages of COVID-19. The key actions of these formulas are likely to control systemic inflammation and/or RBS. The usage of Chinese medicine in the six formulas is consistent with the pathogenesis of COVID-19. Thus, an integrative systems biology approach-combining botanical treatments of conventional antiviral, anti-inflammatory or anti-RBS drugs to treat COVID-19 and its complications - should be explored.

A new biflavonoids from Aster tataricus induced non-apoptotic cell death in A549 cells

A new biflavonoids, (2R,2''R)-7-O-methyl-2,3,2'',3''-tetrahydrorobustaflavone (1), along with five known flavonoids (2-6) were isolated from the MeOH extract of Aster tataricus. Among them, compounds 1-2 were the C-3'-C-6'' type biflavonoids obtained from the genus Aster for the first time. The structures and absolute configurations of compound 1 was confirmed based on extensive spectroscopic and circular dichroism analyses. Compound 1 exhibited moderate cytotoxicity against seven human cancer A549, HepG2, PC3, DU145, MCF-7, LOVO and NCI-H1975 cell lines. Compound 1 remarkably inhibited the proliferation of A549 cancer cells with IC₅₀ value of 5.4 μM. Further preliminary pharmacological study, 1 induces A549 cell death by non-apoptotic forms through flow cytometry and cell scratch assay data.

Isoliquiritigenin Confers Neuroprotection and Alleviates Amyloid-β42-Induced Neuroinflammation in Microglia by Regulating the Nrf2/NF-κB Signaling

Background

Neuroinflammation and oxidative stress are two major pathological characteristics of Alzheimer's disease (AD). Amyloid-β oligomers (AβO), a toxic form of Aβ, promote the neuroinflammation and oxidative stress in the development of AD. Isoliquiritigenin (ISL), a natural flavonoid isolated from the root of liquorice, has been shown to exert inhibitory effects on inflammatory response and oxidative stress.

Objectives

The main purpose of this study is to assess the influence of ISL on inflammatory response and oxidative stress in BV2 cells stimulated with AβO, and to explore the underlying molecular mechanisms.

Methods

3-(4,5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H- tetrazolium bromide (MTT) and lactate dehydrogenase (LDH) cytotoxicity assays were used to assess the toxic or protective effects of ISL. The expression levels of interleukin-1β, interleukin-6, and tumor necrosis factor-α were assessed by quantitative real-time polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assays. Morphological changes in BV2 cells were assessed by immunofluorescence method. Nitric oxide (NO) assay kit was used to determinate the NO production. Western blot, qRT-PCR and immunofluorescence were used to explore the underlying molecular mechanisms.

Results

ISL treatment reduced the production of inflammatory cytokines and NO, and alleviated the morphological changes in BV2 cells induced by AβO. ISL treatment further protected N2a cells from the toxic medium of AβO-stimulated BV2 cells. ISL activated nuclear factor erythroid-2 related factor 2 (Nrf2) signaling and suppressed nuclear factor-κB (NF-κB) signaling in BV2 cells.

Conclusion

ISL suppresses AβO-induced inflammation and oxidative stress in BV2 cells via the regulation of Nrf2/NF-κB signaling. Therefore, ISL indirectly protects neurons from the damage of toxic conditioned media.

Reduction of anoxia-induced bioenergetic disturbance in astrocytes by methanol fruit extract of Tetrapleura tetraptera and in silico evaluation of the effect of its antioxidative constituents on excitotoxicity

Oxidative stress and excitotoxicity are some of the pathophysiological abnormalities in hypoxia-induced brain injury. This study evaluated the intrinsic antioxidant property of methanol fruit extract of Tetrapleura tetraptera (TT), traditionally used for managing brain diseases such as cerebral infarction in West Africa, and its ability to protect primary astrocytes from anoxia-induced cell death. The effect of the phytochemicals present in TT on excitotoxicity was assessed in silico, through docking with human glutamate synthetase (hGS). Chromatographic and spectrophotometric analyses of TT were performed. Primary astrocytes derived from neural stem cells were treated with TT and its effect on astrocyte viability was assessed. TT-treated astrocytes were then subjected to anoxic insult and, cell viability and mitochondrial membrane potential were evaluated. Molecular docking of hGS with detected phytochemicals in TT (aridanin, naringenin, ferulic acid, and scopoletin) was performed and the number of interactions with the lead compounds, aridanin, analyzed. HPLC-DAD analysis of TT revealed the presence of various bioactive phytochemicals. TT demonstrated notable antioxidant and radical scavenging activities. TT also protected astrocytes from anoxic insult by restoring cell viability and preventing alteration to mitochondrial membrane integrity. Aridanin, naringenin, ferulic acid, and scopoletin demonstrated good binding affinities with hGS indicating that Tetrapleura tetraptera is a potential source of new plant-based bioactives relevant in the therapy of neurodegenerative diseases.

Abatement of neurobehavioral and neurochemical dysfunctions in cerebral ischemia/reperfusion injury by Tetrapleura tetraptera fruit extract

ETHNOPHARMACOLOGICAL RELEVANCE

Tetrapleura tetraptera Taub. (family Fabaceae), is generally found in the lowland forest of tropical Africa. Its leaves and fruits are traditionally used in West Africa for the management of brain disorders.

AIM OF THE STUDY

This study evaluated the effect of Tetrapleura tetraptera methanol fruit extract (TT) on bilateral common carotid artery occlusion-induced cerebral ischemia/reperfusion (I/R) injury in male Wistar rats.

MATERIALS AND METHODS

Rats pretreated with TT for 7 days before a 30 min bilateral common carotid artery occlusion and reperfusion for 24 h were assessed for neurobehavioural deficits. Cortical, striatal and hippocampal oxidative stress, pro-inflammatory events, electrolyte imbalance and neurochemical dysfunctions, as well as hippocampal histopathological alterations, were also evaluated. HPLC-DAD analysis was performed to identify likely compounds contributing to the bioactivity of the extract.

RESULTS

TT reduced I/R-induced behavioral deficits and ameliorated I/R-induced oxidative stress by restoring reduced glutathione level, increasing catalase and superoxide dismutase activities, and also reducing both lipid peroxidation and xanthine oxidase activity in the brain. TT attenuated I/R-increased myeloperoxidase and lactate dehydrogenase activities as well as disturbances in Na⁺ and K⁺ levels. Alterations elicited by I/R in the activities of Na⁺/K⁺ ATPase, complex I, glutamine synthetase, acetylcholinesterase, and dopamine metabolism were abated by TT pretreatment. TT prevented I/R-induced histological changes in the hippocampus. HPLC-DAD analysis revealed the presence of aridanin, a marker compound for Tetrapleura tetraptera, and other phytochemicals.

CONCLUSIONS

These findings indicate that Tetrapleura tetraptera fruit has a protective potential against stroke through modulation of redox and electrolyte imbalances, and attenuation of neurotransmitter dysregulation and other neurochemical dysfunctions. Tetrapleura tetraptera fruit could be a promising source for the discovery of bioactives for stroke therapy.

Isoliquiritigenin attenuates diabetic cardiomyopathy via inhibition of hyperglycemia-induced inflammatory response and oxidative stress

BACKGROUND

Inflammation and oxidative stress play essential roles in the occurrence and progression of diabetic cardiomyopathy (DCM). Isoliquiritigenin (ISL), a natural chalcone, exhibits strong anti-inflammatory and antioxidant activities.

HYPOTHESIS/PURPOSE

In this study, we aimed to investigate the protective effects of ISL on DCM using high glucose (HG)-challenged cultured cardiomyocytes and streptozotocin (STZ)-induced diabetic mice.

STUDY DESIGN AND METHODS

Embryonic rat heart-derived H9c2 cells challenged with a high concentration of glucose were used to evaluate the anti-inflammatory and antioxidant effects of ISL. STZ-induced diabetic mice were used to study the effects of ISL in DCM in vivo. Furthermore, cardiac fibrosis, hypertrophy, and apoptosis were explored both in vitro and in vivo.

RESULTS

ISL effectively inhibited HG-induced hypertrophy, fibrosis, and apoptosis probably by alleviating the inflammatory response and oxidative stress in H9c2 cells. Results from in vivo experiments showed that ISL exhibited anti-inflammatory and antioxidant stress activities that were characterized by the attenuation of cardiac hypertrophy, fibrosis, and apoptosis, which resulted in the maintenance of cardiac function. The protective effects of ISL against inflammation and oxidative stress were mediated by the inhibition of mitogen-activated protein kinases (MAPKs) and induction of nuclear factor-erythroid 2 related factor 2 (Nrf2) signaling pathway, respectively.

CONCLUSION

Our results provided compelling evidence that ISL, by virtue of neutralizing excessive inflammatory response and oxidative stress, could be a promising agent in the treatment of DCM. Targeting the MAPKs and Nrf2 signaling pathway might be an effective therapeutic strategy for the prevention and treatment of DCM.

Molecular Docking and ADMET Study of Bioactive Compounds of Glycyrrhiza glabra Against Main Protease of SARS-CoV2

Recent pandemic situation of COVID-19 is caused due to SARS-CoV2 and almost all the countries of the world have been affected by this highly contagious virus. Main protease (M^pro) of this virus is a highly attractive drug target among various other enzymes due to its ability to process poly-protein that is the translated product of the SARS-CoV2 RNA. The present study demonstrates molecular docking study of Glycyrrhiza glabra (Gg) active compounds such as Glycyrrhizic acid (GA), Liquiritigenin (L) and Glabridin (G) against the M^pro. Docking studies shows that these active compounds bind strongly with some of the amino acid residues in the active site of M^pro and inhibits the enzyme strongly. GA, L, and G are proposed to be strong inhibitors of the enzyme and the amino acids: His⁴¹, Gly¹⁴³, Gln¹⁸⁹, Glu ¹⁶⁶, Cys ¹⁴⁵, Thr²⁵, Asn¹⁴², Met⁴⁹, Cys⁴⁴, Thr⁴⁵ and pro¹⁶⁸ present in the active site of M^pro were shown to make non-covalent interaction with these compounds. In silico ADMET properties prediction also shows that Gg active compounds had good solubility, absorption, permeation, non-toxic, and non– carcinogenic characteristics. Our finding concludes that all of the three active compounds of Gg have the potential to be strong inhibitors for M^pro of SARS-CoV2 but glycyrrhizic acid has a high binding affinity and a good ADMET properties than the other two.

MS-based metabolite analysis of two licorice chalcones in mice plasma, bile, feces, and urine after oral administration

Isoliquiritigenin (ILG) and isoliquiritin (ILQ), two kinds of major flavonoids in licorice, are biological active substances with antioxidant, anti-inflammatory, and tumor-suppressive effects. However, their in vivo metabolites, possible material basis of this two licorice chalcones for the treatment of diseases, have not been studied completely. To determine the metabolism of ILG and ILQ, after oral administration of 100 mg/kg/day of these compounds for consecutive 8 days, the metabolites of these two licorice chalcones in mice plasma, urine, feces, and bile were determined using liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry in this study. The structures of those metabolites were tentatively identified according to their fragment pathways, accurate masses, characteristic product ions, metabolism law, and reference standards-matching. As a result, a total of 25 and 29 metabolites of ILG and ILQ were identified, respectively. Seven main metabolic pathways, oxidation and reduction, deglycosylation and glycosylation, dehydroxylation and hydroxylation, demethoxylation and methoxylation, acetylation, glucuronidation, and sulfation, were summarized to tentatively explain how the metabolites were biologically transformed. These results provide the important information on the metabolism of ILG and ILQ, which may be helpful for the further research of their pharmacological mechanism.

The effects of isoliquiritigenin on endometriosis in vivo and in vitro study

BACKGROUND

Endometriosis is a common gynaecological disease characterized by growth of uterine endometrial tissue, outside the uterine cavity, on the ovaries, oviduct and pelvic peritoneum. Isoliquiritigenin (ISL) is a natural flavonoid isolated from the root of licorice (Glycyrrhiza uralensis) and shallot (Allium cepa). ISL has previously shown antioxidant, anti-inflammatory, anti-proliferation and anti-tumor activities.

PURPOSE

This study aimed to investigate the effects of ISL on endometriosis in vivo and in vitro.

METHODS

End1/E6E7 endometriosis cells were treated with ISL and β-estradiol. The MTT assay was used to detect cell viability. Cell migration was evaluated by the wound-healing assay. The expression of epithelial-to-mesenchymal transition (EMT)-related proteins were detected by western blot. Female Balb/c mice, surgically induced to have endometriosis by transplanting uterine tissue into the abdominal cavity, were treated with ISL or vehicle for 4 weeks. Lesion growth was subsequently analyzed by high-resolution ultrasound imaging. Serum and lesion inflammatory cytokines were measured by ELISA. EMT-related proteins and apoptosis-related proteins of endometriotic lesions were detected by western blot.

RESULTS

It was observed that ISL treatment inhibited the viability and migration of End1/E6E7. ISL treatment increased the expression of E-cadherin, and decreased the expression of N-cadherin, Slug and Snail. In the animal model, ISL treatment reduced the volume and weight of endometriotic lesions, decreased serum and lesion inflammatory cytokines, inhibited EMT, and induced apoptosis of the lesions.

CONCLUSION

ISL inhibited the viability, migration and EMT-related proteins of End1/E6E7 cells, reduced the volume and weight of endometriotic lesions, inhibited inflammatory cytokines and EMT, and induced apoptosis of the lesions to improve endometriosis.

Liquiritigenin Decreases Aβ Levels and Ameliorates Cognitive Decline by Regulating Microglia M1/M2 Transformation in AD Mice

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases and is currently incurable. Amyloid β protein (Aβ) deposition is the main pathogenesis of AD, and many studies have shown that Aβ accumulation is toxic to neurons, leading to the inflammatory reaction, neuronal apoptosis, and neurofibrillary tangles. Thus, reducing Aβ levels might be a potential therapeutic strategy for AD. Liquiritigenin (LG), a dihydroflavone monomer compound extracted from natural plant licorice, has a variety of biological activities such as antioxidant, anti-tumor, anti-inflammatory and anti-virus. However, the exact function of LG in the pathogenesis of AD is elusive. Here, we reported that LG could significantly attenuate neuronal apoptosis in Aβ-induced N2A cells and APP/PS1 transgenic mice. Our in vivo and in vitro studies revealed that LG could alleviate the inflammation response, reflected by the reduction of NLRP3 and cleaved caspase-1. Meanwhile, we also found that LG was able to shift M1 type microglia towards M2 type microglia in Aβ-induced BV2 cells and AD mice. Furthermore, LG could reduce the Aβ levels by decreasing APP processing and accelerating Aβ clearance in AD mice. More importantly, daily treatment of LG (30 mg/kg day) for 90 days dramatically ameliorated the spatial learning and memory of AD mice. Taken together, these results suggest that LG can reduce the Aβ levels by regulating the M1/M2 transformation of microglia, thereby reversing memory decline during AD development, suggesting that LG may be a potential therapeutic agent for treating AD.

Isoliquiritigenin Pretreatment Induces Endoplasmic Reticulum Stress-Mediated Hormesis and Attenuates Cisplatin-Induced Oxidative Stress and Damage in LLC-PK1 Cells

Isoliquiritigenin (IsoLQ) is a flavonoid with antioxidant properties and inducer of endoplasmic reticulum (ER) stress. In vitro and in vivo studies show that ER stress-mediated hormesis is cytoprotective; therefore, natural antioxidants and ER stress inducers have been used to prevent renal injury. Oxidative stress and ER stress are some of the mechanisms of damage involved in cisplatin (CP)-induced nephrotoxicity. This study aims to explore whether IsoLQ pretreatment induces ER stress and produces hormesis to protect against CP-induced nephrotoxicity in Lilly Laboratories Cell-Porcine Kidney 1 (LLC-PK1) cells. During the first stage of this study, both IsoLQ protective concentration and pretreatment time against CP-induced toxicity were determined by cell viability. At the second stage, the effect of IsoLQ pretreatment on cell viability, ER stress, and oxidative stress were evaluated. IsoLQ pretreatment in CP-treated cells induces expression of glucose-related proteins 78 and 94 kDa (GRP78 and GRP94, respectively), attenuates CP-induced cell death, decreases reactive oxygen species (ROS) production, and prevents the decrease in glutathione/glutathione disulfide (GSH/GSSG) ratio, free thiols levels, and glutathione reductase (GR) activity. These data suggest that IsoLQ pretreatment has a moderately protective effect on CP-induced toxicity in LLC-PK1 cells, through ER stress-mediated hormesis, as well as by the antioxidant properties of IsoLQ.

Effect of Huoxiang Zhengqi Pill on Early Neurological Deterioration in Patients with Acute Ischemic Stroke Undergoing Recanalization Therapy and Predictive Effect of Essen Score

Early neurologic deterioration (END) in the acute phase of ischemic stroke is a serious clinical event, which is closely related to poor prognosis. Therefore, it is important to identify presentation features that predict END and take relevant treatment measures, as they could help to prevent the deterioration of high-risk patients. The prospective intervention study was carried out from January 2018 to December 2019. We included consecutive patients hospitalized for acute ischemic stroke (AIS) within 6 hours of onset. Patients were randomly assigned (1 : 1) to recanalization therapy plus Huoxiang Zhengqi Pill (HXZQ) (intervention group) or standard recanalization therapy alone (control group). The primary outcome was the development of END according to predefined criteria within the first 1 week of stroke onset. Poisson regression was used to identify predictors for END. Of the 155 patients enrolled in the study (age, 63 ± 11 years; 28.4% female), 20 (12.9%) developed END. Univariate analysis showed that the use of HXZQ and Essen stroke risk score (ESRS) (low risk group) were protective factors for END, while advanced age was a risk factor for END. However, in multivariate analysis, only ESRS (OR, 0.232; 95%CI, 0.058–0.928; P=0.039) and the use of HXZQ (OR, 0.297; 95%CI, 0.096–0.917; P=0.035) were statistically significant. ESRS can be used as the prediction factor of END. HXZQ has small side effects and wide indication. It could be used in the treatment of AIS.

Wenyang Jieyu Decoction Alleviates Depressive Behavior in the Rat Model of Depression via Regulation of the Intestinal Microbiota

Background

Intestinal microbiota plays an important role in the occurrence and treatment of depression. This study investigated whether Wenyang Jieyu decoction (WYJYD) alleviates depressive behavior in the rat model via regulation of the intestinal microbiota.

Methods

Rat model of depression was established by stress stimulus. SD male rats were randomly allocated into normal control, model, model + low-dose WYJYD (1.89 g/kg/d), model + medium-dose WYJYD (3.08 g/kg/d), model + high-dose WYJYD (7.56 g/kg/d), and model + fluoxetine (3.33 mg/kg/d) groups. Behavioral changes were observed using forced swim test. Histopathological changes in hippocampal tissue were examined by HE staining. Indicators in serum were detected by ELISA. Indicators in hippocampal tissue were detected by qPCR and western blot. Microbiota distribution in feces was detected using high-throughput 16S rRNA gene sequencing.

Results

Compared with the model group, the immobility time in WYJYD and fluoxetine groups was significantly decreased (P < 0.05), and the cell structure was significantly improved. Compared with the model group, the 5-hydroxytryptamine (5-HT) and norepinephrine (NE) levels in medium- and high-dose WYJYD groups and the brain-derived neurotrophic factor (BDNF) level in the high-dose WYJYD group were significantly increased (P < 0.05, all), and the fibroblast growth factor-2 (FGF2), forkhead box protein G1 (FOXG1), and phospho-protein kinase B/protein kinase B (p-AKT/AKT) expressions were increased with WYJYD treatments. The Chao1 and ACE indices in high-dose WYJYD and the Simpson and Shannon indices in medium-dose WYJYD were significantly different than the model group. The similarity of the intestinal microbial community of each group after WYJYD treatment tended to be closer to the control group. Compared with the model group, as the dosage of WYJYD increased, the abundance of genera Coprococcus, Lachnospira, and rc4-4 was significantly increased, while the abundance of genera Desulfovibrio, Burkholderia, and Enterococcus was significantly decreased.

Conclusion

WYJYD may alleviate the depressive behavior of the rat model by regulating the intestinal microbiota and neurotransmitters.

In vitro Evaluation of the Anti-inflammatory Effects of Thymoquinone in Osteoarthritis and in silico Analysis of Inter-Related Pathways in Age-Related Degenerative Diseases

Chronic inflammation is a common underlying factor in osteoarthritis (OA) and most age-related degenerative diseases. As conventional therapies help only in partial alleviation of symptoms in OA, stem cell-based therapies and herbal supplements are being widely explored. Thymoquinone (TQ), an active ingredient of Nigella sativa is reported to have immunomodulatory, anti-inflammatory and antioxidant properties. We evaluated the effects of TQ on bone marrow MSCs (BM-MSCs) derived from OA patients and its interrelated pathways in inflammation and age-related degenerative diseases using Ingenuity Pathway Analysis (IPA) as well as possible molecular targets using SwissTargetPrediction. BM-MSCs were derived from OA patients and their stemness properties were characterized by studying the MSCs related CD surface marker expression and differentiation into adipocytes, osteoblasts, and chondrocytes. Treatment with TQ (100 nM-5 μM) demonstrated cell death, especially at higher concentrations. MTT assay demonstrated a significant concentration-dependent decrease in cell viability which ranged from 20.04% to 69.76% with higher doses (300 nM, 1 μM, and 5 μM), especially at 48h and 72h. Additional cell viability testing with CellTiter-Blue also demonstrated a significant concentration-dependent decrease in cell viability which ranged from 27.80 to 73.67% with higher doses (300 nM, 1 μM, 3 μM, and 5 μM). Gene expression analysis following treatment of BM-MSCs with TQ (1 and 3 μM) for 48h showed upregulation of the anti-inflammatory genes IL-4 and IL-10. In contrast, the pro-inflammatory genes namely IFN-γ, TNF-α, COX-2, IL-6, IL-8, IL-16, and IL-12A although were upregulated, compared to the lower concentration of TQ (1 μM) they were all decreased at 3 μM. The pro-apoptotic BAX gene was downregulated while the SURVIVIN gene was upregulated. IPA of the molecular interaction of TQ in inflammation and age-related degenerative diseases identified canonical pathways directly related to synaptogenesis, neuroinflammation, TGF-β, and interleukin signaling. Further screening led to the identification of 36 molecules that are involved in apoptosis, cell cycle regulation, cytokines, chemokines, and growth factors. SwissTargetPrediction of TQ identified potential molecular targets with high probability. TQ exerted anti-inflammatory effects and therefore can be a useful adjuvant along with conventional therapies against inflammation in OA and other age-related degenerative diseases.

Protective effect of isoliquiritigenin on experimental diabetic nephropathy in rats: Impact on Sirt-1/NFκB balance and NLRP3 expression

The prevalence of diabetes mellitus (DM) drastically increases worldwide. Persistent hyperglycemia affects body microvasculature causing injuries to kidney producing diabetic nephropathy (DNE). Manifestation of these microvascular complications is associated with disturbed redox homeostasis. The current study evaluated the effect of isoliquiritigenin (ISLQ), a bioactive chalcone found in licorice which is known for its antioxidant effect, on diabetes-induced renal injury. DM was prompted in male rats by streptozotocin (STZ, 50 mg/kg, intraperitoneally). ISLQ was administrated by oral gavage for 8 weeks at a dose (20 mg/kg/day). Features of renal injury were observed in kidneys of diabetic rats including, albuminuria and deteriorated renal function. Renal dysfunction was associated with reduced sirtuin-1 (Sirt-1) expression, increased renal oxidative stress, nucleotide-binding domain and leucine-rich repeat containing protein-3 (NLRP3), nuclear factor-κB (NFκB) and inflammatory cytokines interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). Moreover, there was significant downregulation of anti-inflammatory cytokine interleukin-10 (IL-10), glomerular and tubular injury and collagen accumulation. ISLQ administration preserved renal function and architecture, restored Sirt1 and renal oxidant-antioxidant balance, dampened inflammation and attenuated collagen accumulation. It can be inferred that ISLQ possess a protective effect and could have a potential as a food supplement to halt development and progression of DNE.

Metabolic profiling of mice plasma, bile, urine and feces after oral administration of two licorice flavonones

ETHNOPHARMACOLOGICAL RELEVANCE

Licorice is an ancient food and medicinal plant. Liquiritigenin and liquiritin, two kinds of major flavonoes in licorice, are effective substances used as antioxidant, anti-inflammatory and tumor-suppressive food, cosmetics or medicines. However, their in vivo metabolites have not been fully explored.

AIM OF STUDY

To clarify the metabolism of liquiritigenin and liquiritin in mice.

MATERIALS AND METHODS

In this study, we developed a liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry approach to determine the metabolites in mice plasma, bile, urine and feces after oral administration of liquiritigenin or liquiritin. The structures of those metabolites were tentatively identified according to their fragment pathways, accurate masses, characteristic product ions, metabolism laws or reference standard matching.

RESULTS

A total of 26 and 24 metabolites of liquiritigenin or liquiritin were respectively identified. The products related with apigenin, luteolin or quercetin were the major metabolites of liquiritigenin or liquiritin in mice. Seven main metabolic pathways including (de)hydrogenation, (de)hydroxylation, (de)glycosylation, (de)methoxylation, acetylation, glucuronidation and sulfation were summarized to tentatively explain their biotransformation.

CONCLUSION

This study not only can provide the evidence for in vivo metabolites and pharmacokinetic mechanism of liquiritigenin and liquiritin, but also may lay the foundation for further development and utilization of liquiritigenin, liquiritin and then licorice.

Flavonoids in Cancer Metastasis

Metastasis represents a serious complication in the treatment of cancer. Flavonoids are plant secondary metabolites exerting various health beneficiary effects. The effects of flavonoids against cancer are associated not only with early stages of the cancer process, but also with cancer progression and spread into distant sites. Flavonoids showed potent anti-cancer effects against various cancer models in vitro and in vivo, mediated via regulation of key signaling pathways involved in the migration and invasion of cancer cells and metastatic progression, including key regulators of epithelial-mesenchymal transition or regulatory molecules such as MMPs, uPA/uPAR, TGF-β and other contributors of the complex process of metastatic spread. Moreover, flavonoids modulated also the expression of genes associated with the progression of cancer and improved inflammatory status, a part of the complex process involved in the development of metastasis. Flavonoids also documented clear potential to improve the anti-cancer effectiveness of conventional chemotherapeutic agents. Most importantly, flavonoids represent environmentally-friendly and cost-effective substances; moreover, a wide spectrum of different flavonoids demonstrated safety and minimal side effects during long-termed administration. In addition, the bioavailability of flavonoids can be improved by their conjugation with metal ions or structural modifications by radiation. In conclusion, anti-cancer effects of flavonoids, targeting all phases of carcinogenesis including metastatic progression, should be implemented into clinical cancer research in order to strengthen their potential use in the future targeted prevention and therapy of cancer in high-risk individuals or patients with aggressive cancer disease with metastatic potential.

The antioxidant activity and neuroprotective mechanism of isoliquiritigenin

Glycyrrhizae radix has been widely accepted as a functional food in Asia. Isoliquiritigenin is a characteristic bioactive chemical in this medicinal plant. In this work, the neuroprotective effect of isoliquiritigenin and the possible mechanisms were investigated. The results revealed that isoliquiritigenin exhibited better neuroprotective and antioxidant activities than quercetin, a commercial natural antioxidant. Isoliquiritigenin significantly inhibited the release of lactate dehydrogenase, and the generation of reactive oxygen species in H₂O₂-treated cells. The activities of superoxide dismutase, glutathione peroxidase and catalase were improved. The mRNA expression levels related to oxidative defense and cell apoptosis were reversed by isoliquiritigenin. Moreover, isoliquiritigenin might inhibit the cell apoptosis via ameliorating the loss of mitochondrial membrane potential and the change of nucleus morphology.

Isoliquiritigenin triggers developmental toxicity and oxidative stress-mediated apoptosis in zebrafish embryos/larvae via Nrf2-HO1/JNK-ERK/mitochondrion pathway

Isoliquiritigenin (ISL) is an emerging natural flavonoid found in the roots of licorice, exhibits antioxidant, anti-cancer, anti-inflammatory, anti-allergic, cardioprotective, hepatoprotective and neuroprotective properties. However, the effect of ISL in embryonic development is yet to be elucidated, and the mechanisms underlying its target-organ toxicity and harmful side effects are still unclear. In the present study, we employed zebrafish embryos to study the developmental toxicity effect of ISL and its underlying mechanisms. Zebrafish embryos upon treatment with either vehicle control (0.1% DMSO) or ISL solutions for 4-96 h post fertilization (hpf) showed that ISL exposure instigated severe developmental toxicity in heart, liver, and nervous system. Mortality and morphological abnormalities were also observed. High concentrations of ISL exposure resulted in abnormal phenotypes and embryonic malformations including pericardial edema, swim bladder defects, yolk retention, curved body shape and shortening of body length. Moreover, ISL exposure led to significant loss of dopaminergic neurons accompanied by reduced locomotor behaviour. Apoptotic cells were predominantly located in the heart area of 96 hpf embryo. Additionally, ISL significantly increased the levels of reactive oxygen species, lipid peroxidation content and decreased antioxidant enzyme activities. The expressions pattern of apoptosis-related genes Bad, Cyto c, Caspase-9, Caspase-3 and Bax/Bcl-2 indicated that the oxidative stress-induced apoptosis triggered by ISL suggest involvement of Nrf2-HO1/JNK-ERK/mitochondrion pathways. In conclusion, here we provide first evidence that demonstrate ISL-induced dose-dependent developmental toxicity in zebrafish embryos. Furthermore, gene expression patterns in the embryos correlate the above and reveal potential genetic mechanisms of developmental toxicity.

Differential annotation of converted metabolites (DAC-Met): Exploration of Maoto (Ma-huang-tang)-derived metabolites in plasma using high-resolution mass spectrometry

INTRODUCTION

Traditional herbal medicine (THM) contains a vast number of natural compounds with varying degrees of pharmacological activity. To elucidate the mode of action, comprehensive metabolite profiling in the plasma before and after administration of THM is essential.

OBJECTIVE

The aim of this study was to explore and identify/annotate converted metabolites after administration of THM in humans.

METHODS

We performed untargeted metabolome analysis of human plasma collected before and after administration of maoto (ma-huang-tang), a traditional Japanese Kampo medicine. Maoto-derived metabolites were then selected and annotated following the DAC-Met strategy, which is an annotation method that uses mass differences of major metabolic reactions among the detected peaks and a differential network analysis.

RESULTS

About 80% of maoto-derived components were found to be converted forms. Following DAC-Met, the structures of 15 previously unidentified metabolites were determined, and five of these were later confirmed with authentic standards. Using published literature, we also reconstructed the metabolic pathway of maoto components in humans. A kinetic time-course analysis revealed their diverse kinetic profiles.

CONCLUSION

The results demonstrated that time-resolved comprehensive metabolite profiling in plasma using the DAC-Met strategy is highly useful for elucidating the complex nature of THM.

Dietary Compound Isoliquiritigenin, an Antioxidant from Licorice, Suppresses Triple-Negative Breast Tumor Growth via Apoptotic Death Program Activation in Cell and Xenograft Animal Models

Patients with triple-negative breast cancer have few therapeutic strategy options. In this study, we investigated the effect of isoliquiritigenin (ISL) on the proliferation of triple-negative breast cancer cells. We found that treatment with ISL inhibited triple-negative breast cancer cell line (MDA-MB-231) cell growth and increased cytotoxicity. ISL reduced cell cycle progression through the reduction of cyclin D1 protein expression and increased the sub-G1 phase population. The ISL-induced apoptotic cell population was observed by flow cytometry analysis. The expression of Bcl-2 protein was reduced by ISL treatment, whereas the Bax protein level increased; subsequently, the downstream signaling molecules caspase-3 and poly ADP-ribose polymerase (PARP) were activated. Moreover, ISL reduced the expression of total and phosphorylated mammalian target of rapamycin (mTOR), ULK1, and cathepsin B, whereas the expression of autophagic-associated proteins p62, Beclin1, and LC3 was increased. The decreased cathepsin B cause the p62 accumulation to induce caspase-8 mediated apoptosis. In vivo studies further showed that preventive treatment with ISL could inhibit breast cancer growth and induce apoptotic and autophagic-mediated apoptosis cell death. Taken together, ISL exerts an effect on the inhibition of triple-negative MDA-MB-231 breast cancer cell growth through autophagy-mediated apoptosis. Therefore, future studies of ISL as a supplement or alternative therapeutic agent for clinical trials against breast cancer are warranted.

Synthesis and biological evaluation of isoliquiritigenin derivatives as a neuroprotective agent against glutamate mediated neurotoxicity in HT22 cells

Glutamate-induced neurotoxicity is characterized by cellular Ca²⁺ uptake, which is upstream of reactive oxygen species (ROS)-induced apoptosis signaling and MAPKs activation. In the present study, we synthesized isoliquiritigenin analogs with electron-donating and electron-withdrawing functional groups. These analogs were evaluated for neuroprotective effect against glutamate-induced neurotoxicity in HT22 cells. Among these analogs, compound BS11 was selected as a potent neuroprotective agent. Cellular Ca²⁺ concentration, ROS level, MAPKs activation and AIF translocation to the nucleus were increased upon treatment with 5 mM glutamate. In contrast, we identified that compound BS11 reduced the cellular Ca²⁺ concentration and ROS level upon glutamate exposure. Western blot analysis showed that MAPK activation was decreased by treatment with compound BS11. We further identified that cotreatment of compound BS11 and glutamate inhibited translocation of AIF to the nucleus.

Comprehensive investigation of mechanism and effective ingredients of Fangji Huangqi Tang by serum pharmacochemistry and network pharmacology

Fangji Huangqi Tang (FHT), has been reported to show effects on nephrotic syndrome, but its mechanism of action and bioactive components have not yet been determined. In this study, a method using UPLC-HRMS/MS was established for the detection and identification of the chemical constituents and metabolites absorbed into the blood. Absorbed components in serum were then used for the network pharmacology analysis to deduce the mechanism and effective components. A total of 86 compounds were identified or tentatively characterized. Based on the same instrumental conditions, 85 compounds were found in rat serum after oral administration of FHT, including 22 prototypes and 63 metabolites. Network pharmacology analysis showed that absorbed components, such as (3R)-2',3',4',7-tetrahydroxyisoflavan, astrapterocarpan, cycloastragenol, 7,2'-dihydroxy-3',4'-dimethoxyisoflavan, astragaloside IV, astrapterocarpan glucoside and glycyrrhetinic acid, could be responsible for the pharmacological activity of nephrotic syndrome by regulating the VEGF signaling pathway, focal adhesion and MAPK signaling pathway. Furthermore, the pathway-target network showed that the MAPK1, AKT2 and CDC42 were involved in the signal pathways above. This study provides a scientific basis for the mechanism and effective ingredients of FHT.