Network Pharmacology, Molecular Docking Analysis and Molecular Dynamics Simulation of Scutellaria baicalensis in the Treatment of Liver Fibrosis.

BACKGROUND: Traditional Chinese medicine Scutellaria Baicalensis (SB), one of the clinical firstline heat-clearing drugs, has obvious symptomatic advantages for hepatic fibrosis with dampness-heat stasis as its syndrome. We aim to predict and validate the potential mechanism of Scutellaria baicalensis active ingredients against liver fibrosis more scientifically and effectively. METHODS: The underlying mechanism of Scutellaria baicalensis in inhibiting hepatic fibrosis was studied by applying network pharmacology, molecular docking and molecular dynamics simulation. Expression levels of markers in activated Hepatic Stellate Cells (HSC) after administration of three Scutellaria baicalensis extracts were determined by Western blot and Real-time PCR, respectively, in order to verify the anti-fibrosis effect of the active ingredients Results: There are 164 common targets of drugs and diseases screened and 115 signaling pathways obtained, which were mainly associated with protein phosphorylation, senescence and negative regulation of the apoptotic process. Western blot and Real-time PCR showed that Scutellaria baicalensis extracts could reduce the expression of HSC activation markers, and Oroxylin A had the strongest inhibitory effect on it. Molecular docking results showed that Oroxylin A had high binding activity to target proteins. Molecular dynamics simulation demonstrates promising stability of the Oroxylin A-AKT1 complex over the simulated MD time of 200 ns. CONCLUSION: Scutellaria baicalensis active ingredients may inhibit HSC proliferation, reduce the generation of pro-inflammatory factors and block the anti-inflammatory effect of inflammatory signal transduction by inducing HSC apoptosis and senescence, thus achieving the effect of anti-fibrosis.

Oroxylin A suppress LL-37 generated rosacea-like skin inflammation through the modulation of SIRT3-SOD2-NF-κB signaling pathway.

Rosacea is a long-term inflammatory skin disease associated with the dysfunction of vascular and immunological systems. Treatment options for rosacea are difficult to implement. Oroxylin A(OA), a traditional Chinese medicine, has anti-inflammation effects in a variety of inflammatory diseases. However, it is not known that whether OA exerts protective effects against LL-37-induced rosacea. In this study, bioinformatics analyses showed that the mechanisms of rosacea and the pharmacological targets of OA were highly overlapped. Subsequently, it was shown that the administration of OA resulted in a notable amelioration of rosacea-like skin lesions, as evidenced by a reduction in immune cell infiltration, modulation of cytokine production, and inhibition of angiogenesis. Plus, it was shown that OA effectively suppressed the generation of ROS generated by LL-37, as well as the subsequent activation of NF-κB signaling pathway. To explore further, we found that OA inhibited LL-37-induced ROS production via SIRT3-SOD2 signaling pathway in keratinocytes. Based on the aforementioned evidence, it can be inferred that OA exhibits a mitigating effect on the inflammatory response in rosacea by modulating the SIRT3-SOD2-NF-κB signaling pathway.

Cellular and molecular mechanisms of oroxylin A in cancer therapy: Recent advances.

Seeking an effective and safe scheme is the common goal of clinical treatment of tumor patients. In recent years, traditional Chinese medicine has attracted more and more attention in order to discover new drugs with good anti-tumor effects. Oroxylin A (OA) is a compound found in natural Oroxylum indicum and Scutellaria baicalensis Georgi plants and has been used in the treatment of various cancers. Studies have shown that OA has a wide range of powerful biological activities and plays an important role in neuroprotection, anti-inflammation, anti-virus, anti-allergy, anti-tumor and so on. OA shows high efficacy in tumor treatment. Therefore, it has attracted great attention of researchers all over the world. This review aims to discuss the anti-tumor effects of OA from the aspects of cell cycle arrest, induction of cell proliferation and apoptosis, induction of autophagy, anti-inflammation, inhibition of glycolysis, angiogenesis, invasion, metastasis and reversal of drug resistance. In addition, the safety and toxicity of the compound were also discussed. As a next step, to clarify the benefits and adverse effects of Oroxylin A in cancer patients further experiments, especially clinical trials, are needed.

Oroxylin A ameliorates ultraviolet radiation-induced premature skin aging by regulating oxidative stress via the Sirt1 pathway.

Skin is susceptible to premature aging in response to ultraviolet (UV) radiation-induced oxidative stress, which can ultimately result in aberrant aging or age-related disorders. Accordingly, strategies that can be adopted to mitigate oxidative stress may contribute to protecting skin from induced aging-related damage, thereby offering promising approaches for the treatment of skin diseases and disorders. In this regard, oroxylin A (OA), a natural flavonoid isolated from certain plants used in traditional Chinese medicine, is considered to have notable antioxidant, anti-inflammatory, and anti-apoptotic properties, and is often used to treat certain inflammatory diseases. To date, however, there has been comparatively little research on the effects of OA with respect skin aging. In this study, we utilized UV radiation-induced mouse and cellular models of aging to assess the efficacy of OA in protecting against skin aging. Subsequently, to elucidate the potential mechanisms underlying the protective effect of OA on skin aging, we performed molecular docking analysis to investigate the involvement of the anti-aging gene Sirt1, which was further confirmed on the basis of Sirt1 gene silencing. We accordingly demonstrated that by promoting an increase in the expression of Sirt1, OA can contribute to suppressing UV-induced skin photo-aging in cells/mice by reducing oxidative stress. Furthermore, we established that by activating Sirt1, OA can also promote the dissociation of Nrf2 from Keap1 and its subsequent nuclear translocation. Collectively, our findings in this study reveal OA to be an effective natural compound that can be administered to delay the aging of skin triggered by UV, both in vivo and in vitro, by binding to Sirt1 to promote the deacetylation and nuclear translocation of Nrf2, thereby contributing to a reduction in oxidative stress. These findings may this provide a therapeutic target for the prevention of skin aging or aging-induced skin diseases.

Anticancer potential of oroxylin A: from mechanistic insight to synergistic perspectives.

Oroxylin A (OA), a well-known constituent of the root of Scutellariae plants, has been used in ethnomedicine already for centuries in treating various neoplastic disorders. However, only recent molecular studies have revealed the different mechanisms behind its action, demonstrating antiproliferative, anti-inflammatory, and proapoptotic effects, restricting also the spread of cancer cells to distant organs. A variety of cellular targets and modulated signal transduction pathways regulated by OA have been determined in diverse cells derived from different malignant tissues. In this review article, these anticancer activities are thoroughly described, representing OA as a potential lead structure for the design of novel more potent anticancer medicines. In addition, co-effects of this natural compound with conventional anticancer agents are analyzed and the advantages provided by nanotechnological methods for more efficient application of OA are discussed. In this way, OA might represent an excellent example of using ethnopharmacological knowledge for designing modern medicines.

Inhibitory Effect of Oroxylin A in a Mouse Model of Atopic Dermatitis.

Scutellaria baicalensis has long been used in Asian traditional medicine to prevent and treat suppurative dermatitis, allergic diseases, inflammation, hyperlipemia, and arteriosclerosis. Oroxylin A is a flavone present in Scutellaria baicalensis. Because the root extracts of Scutellaria baicalensis have been shown to have anti-dermatitis effects, the authors investigated the effects of oroxylin A on chemically induced atopic dermatitis (AD) in an in vivo AD model induced by 1-chloro-2,4-dinitrobenzene (CDNB) in BALB/c mice. CDNB-induced skin hypertrophy and accumulation of mast cells in the epidermis and dermis were significantly decreased by oroxylin A. Increased serum levels of immunoglobulin E, as well as pro-inflammatory chemokines and cytokines in the skin and lymph nodes, were significantly decreased by oroxylin A. Suppression of immune responses in the skin and lymph nodes by oroxylin A decreased the symptoms of AD. Thus, these results proved that oroxylin A is an effective component of Scutellaria baicalensis for treating the symptoms of AD.

Oroxylin A: A Promising Flavonoid for Prevention and Treatment of Chronic Diseases.

There have been magnificent advancements in the understanding of molecular mechanisms of chronic diseases over the past several years, but these diseases continue to be a considerable cause of death worldwide. Most of the approved medications available for the prevention and treatment of these diseases target only a single gene/protein/pathway and are known to cause severe side effects and are less effective than they are anticipated. Consequently, the development of finer therapeutics that outshine the existing ones is far-reaching. Natural compounds have enormous applications in curbing several disastrous and fatal diseases. Oroxylin A (OA) is a flavonoid obtained from the plants Oroxylum indicum, Scutellaria baicalensis, and S. lateriflora, which have distinctive pharmacological properties. OA modulates the important signaling pathways, including NF-κB, MAPK, ERK1/2, Wnt/ß-catenin, PTEN/PI3K/Akt, and signaling molecules, such as TNF-α, TGF-ß, MMPs, VEGF, interleukins, Bcl-2, caspases, HIF-1α, EMT proteins, Nrf-2, etc., which play a pivotal role in the molecular mechanism of chronic diseases. Overwhelming pieces of evidence expound on the anti-inflammatory, anti-bacterial, anti-viral, and anti-cancer potentials of this flavonoid, which makes it an engrossing compound for research. Numerous preclinical and clinical studies also displayed the promising potential of OA against cancer, cardiovascular diseases, inflammation, neurological disorders, rheumatoid arthritis, osteoarthritis, etc. Therefore, the current review focuses on delineating the role of OA in combating different chronic diseases and highlighting the intrinsic molecular mechanisms of its action.

Modulation of diverse oncogenic signaling pathways by oroxylin A: An important strategy for both cancer prevention and treatment.

BACKGROUND: Regardless of major advances in diagnosis, prevention and treatment strategies, cancer is still a foreboding cause due to factors like chemoresistance, radioresistance, adverse side effects and cancer recurrence. Therefore, continuous development of unconventional approaches is a prerequisite to overcome foregoing glitches. Natural products have found their way into treatment of serious health conditions, including cancer since ancient times. The compound oroxylin A (OA) is one among those with enormous potential against different malignancies. It is a flavonoid obtained from the several plants such as Oroxylum indicum, Scutellaria baicalensis and S. lateriflora, Anchietea pyrifolia, and Aster himalaicus. PURPOSE: The main purpose of this study is to comprehensively elucidate the anticancerous effects of OA against various malignancies and unravel their chemosensitization and radiosensitization potential. Pharmacokinetic and pharmacodynamic studies of OA have also been investigated. METHOD: The literature on antineoplastic effects of OA was searched in PubMed and Scopus, including in vitro and in vivo studies and is summarized based on a systematic review protocol prepared according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The term "oroxylin A" was used in combination with "cancer" and all the title, abstracts and keywords appeared were considered. RESULTS: In Scopus, a total of 157 articles appeared out of which 103 articles that did not meet the eligibility criteria were eliminated and 54 were critically evaluated. In PubMed, from the 85 results obtained, 26 articles were eliminated and 59 were included in the preparation of this review. Mounting number of studies have illustrated the anticancer effects of OA, and its mechanism of action. CONCLUSION: OA is a promising natural flavonoid possessing wide range of pleiotropic properties and is a potential anticancer agent. It has a great potential in the treatment of multiple cancers including brain, breast, cervical, colon, esophageal, gall bladder, gastric, hematological, liver, lung, oral, ovarian, pancreatic and skin. However, lack of pharmacokinetic studies, toxicity assessments, and dose standardization studies and adverse effects limit the optimization of this compound as a therapeutic agent.

A Candidate Drug Screen Strategy: The Discovery of Oroxylin A in Scutellariae Radix Against Sepsis via the Correlation Analysis Between Plant Metabolomics and Pharmacodynamics.

Sepsis is an acute systemic infectious disease with high mortality, which urgently needs more effective treatment. Scutellariae radix (SR), a commonly used traditional Chinese medicine (TCM) for clearing heat and detoxification, contains rich natural products possessing anti-inflammatory activity. In previous studies, it was found that the anti-inflammatory activities of SR extracts from different ecological conditions varied wildly. Based on this, in the present study, a screening strategy of antisepsis active components from SR based on correlation analysis between plant metabolomics and pharmacodynamics was established, and the mechanism was explored. First of all, a mass spectrum database of SR (above 240 components) was established to lay the foundation for the identification of plant metabolomics by liquid chromatography tandem mass spectrometry (LC-MS/MS). Through the correlation analysis between plant metabolomics and anti-inflammatory activity of SR from different ecology regions, 10 potential components with high correlation coefficients were preliminarily screened out. After the evaluation of anti-inflammatory activity and toxicity at the cellular level, the pharmacodynamic evaluation in vivo found that oroxylin A had the potentiality of antisepsis both in LPS- and CLP-induced endotoxemia mice. Network pharmacology and Western blot (WB) results indicated that oroxylin A significantly inhibited the toll-like receptor 4/nuclear factor-kappa B (TLR4/NF-κB) signaling pathway, which was further confirmed by secreted embryonic alkaline phosphatase (SEAP) assay. Moreover, the molecular docking analysis indicated that oroxylin A might competitively inhibit LPS binding to myeloid differentiation 2 (MD-2) to block the activation of TLR4. The study provided a feasible research strategy for the screening and discovery of antisepsis candidate drugs from TCM.

A multi-herb-combined remedy to overcome hyper-inflammatory response by reprogramming transcription factor profile and shaping monocyte subsets.

Traditional Chinese multi-herb-combined prescriptions usually show better performance than a single agent since a group of effective compounds interfere multiple disease-relevant targets simultaneously. Huang-Lian-Jie-Du decoction is a remedy made of four herbs that are widely used to treat oral ulcers, gingivitis, and periodontitis. However, the active ingredients and underlying mechanisms are not clear. To address these questions, we prepared a water extract solution of Huang-Lian-Jie-Du decoction (HLJDD), called it as WEH (Water Extract Solution of HLJDD), and used it to treat LPS-induced systemic inflammation in mice. We observed that WEH attenuated inflammatory responses including reducing production of cytokines, chemokines and interferons (IFNs), further attenuating emergency myelopoiesis, and preventing mice septic lethality. Upon LPS stimulation, mice pretreated with WEH increased circulating Ly6C- patrolling and splenic Ly6C+ inflammatory monocytes. The acute myelopoiesis related transcriptional factor profile was rearranged by WEH. Mechanistically we confirmed that WEH interrupted LPS/TLR4/CD14 signaling-mediated downstream signaling pathways through its nine principal ingredients, which blocked LPS stimulated divergent signaling cascades, such as activation of NF-κB, p38 MAPK, and ERK1/2. We conclude that the old remedy blunts LPS-induced "danger" signal recognition and transduction process at multiple sites. To translate our findings into clinical applications, we refined the crude extract into a pure multicomponent drug by directly mixing these nine chemical entities, which completely reproduced the effect of protecting mice from lethal septic shock. Finally, we reduced a large number of compounds within a multi-herb water extract to seven-chemical combination that exhibited superior therapeutic efficacy compared with WEH.

Oroxylin A is a severe acute respiratory syndrome coronavirus 2-spiked pseudotyped virus blocker obtained from Radix Scutellariae using angiotensin-converting enzyme II/cell membrane chromatography.

The current worldwide outbreak of the coronavirus disease 2019 (COVID-19) has been declared a public health emergency. The angiotensin-converting enzyme II (ACE2) has been reported as the primary host-cell receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative virus of COVID-19. In this study, we screened ACE2 ligands from Radix Scutellariae and investigated its suppressive effect on SARS-CoV-2 spiked pseudotyped virus in vitro. HEK293T cells stably expressing ACE2 receptors (ACE2 cells) were used to provide the receptor for the ACE2/cell membrane chromatography (CMC) method used for analysis. The SARS-CoV-2-spiked pseudotyped virus was used to examine the anti-viropexis effect of the screened compounds in ACE2 cells. Molecular docking and the surface plasmon resonance (SPR) assay were used to determine the binding properties. Oroxylin A exhibited an appreciable suppressive effect against the entrance of the SARS-CoV-2-spiked pseudotyped virus into ACE2 cells, which showed good binding to ACE2 as determined using SPR and CMC. Oroxylin A was shown to be a potential candidate in the treatment for COVID-19 by virtue of its blocking the entrance of SARS-CoV-2 into ACE2 cells by specifically binding to the ACE2 receptor.

Oroxylin A Exerts Its Antitumor Effects in Human Gallbladder Cancer via Inhibition of the PTEN/PI3K/AKT Signaling Pathway.

Gallbladder carcinoma (GBC) is one of the most common carcinomas of the biliary tract and is associated with aggressive malignancy and poor prognosis. Current therapeutic strategies, including surgery, radiotherapy, and chemotherapy, are not sufficient for the treatment of GBC, and new therapeutic strategies are urgently needed. The antitumor effects of oroxylin A (OrA), a natural flavonoid extracted from the dried roots of medicinal plants such as Scutellariae species (Radix Scutellariae), have been widely reported in various cancers. In this study, we first evaluated the antitumor activity and the underlying mechanism of action of OrA on GBC cells in vitro. Our results revealed that OrA significantly attenuated the proliferation, migration, and invasion of GBC cells, simultaneously promoting their apoptosis. Suppression of the phosphate on and tension homology deleted chromosome ten (PTEN)/phosphatidylinositol-3 kinase (PI3K)/protein kinase B (AKT) signaling pathway was found to be the underlying mechanism involved in the antitumor activity of OrA. In addition, experiments using a tumor xenograft mouse model confirmed the antitumor effects of OrA in vivo. Taken together, our findings indicate that OrA could be a potential antitumor agent for the prospective treatment of GBC.

[Simultaneous determination of four components of Shuganning Injection in rat plasma by UPLC-MS/MS and its application to a pharmacokinetic study].

This study aims to reveal the pharmacokinetics of Shuganning Injection in normal rats. In this experiment,ultra-high performance liquid chromatography-electrospray-tandem mass spectrometry( UPLC-ESI-MS/MS) was used to establish an analytical method for simultaneous determination of chlorogenic acid,gardenioside,oroxylin A and baicalin in rat plasma. Then,the non-compartmental model( NCA) in Phoenix WinN onL in 6. 4 software was used to fit pharmacokinetic parameters. The methodological validation showed that the linear relationship of the components in rat plasma samples were good( r>0. 995). The recovery rate and matrix effect of plasma samples with low,middle and high concentration were 79. 14%-101. 4%. The intra-day and inter-day precision,accuracy and stability meet the requirements of biological sample analysis. The half-life( t1/2) of chlorogenic acid,gardenioside,oroxylin A did not change significantly and the area under blood concentration-time curve( AUC0-t) is proportional to the dose,which suggested that three components showed a linear kinetic characteristics,but baicalin showed nonlinear kinetic characteristics. Moreover,the retention time of each component in rats was short. The established UPLC-MS/MS quantitative analysis method is rapid,sensitive and accurate,which can be used for the determination of chlorogenic acid,gardenioside,oroxylin A and baicalin in rat plasma and pharmacokinetic study of Shuganning Injection.

Oroxylin A exerts anticancer effects on human ovarian cancer cells via the PPARγ­dependent reversal of the progesterone receptor membrane component 1/2 expression profile.

Ovarian cancer is the most lethal gynecological cancer worldwide. To date, the therapeutic approaches available for the treatment of ovarian cancer are still very limited. The present study first demonstrated that the Chinese herb, Oroxylin A, exerts inhibitory effects on both the migratory ability and viability of ovarian cancer cells. Notably, the inhibitory effects of the drug occurred in a dose­dependent manner. Oroxylin A only inhibited cell migration at the lower dose, whereas it induced early or late apoptosis at the middle or higher doses, respectively. Mechanistically, Oroxylin A increased peroxisome proliferator­activated receptor gamma (PPARγ) expression and altered the expression profile of progesterone receptor membrane component (PGRMC)1/2. Notably, PPARγ was revealed to play a central role in Oroxylin A­mediated anticancer activity. The silencing of PPARγ significantly abrogated Oroxylin A­induced apoptotic cell death and restored the expression profile of the PGRMC1/2 family in ovarian cancer cells. Collectively, the present study revealed that Oroxylin A exerted marked anticancer effects against ovarian cancer in vitro. Thus, Oroxylin A may have potential for use as a complementary therapy in the treatment of ovarian cancer.

Pharmacokinetics, tissue distribution and excretion study of Oroxylin A, Oroxylin A 7-O-glucuronide and Oroxylin A sodium sulfonate in rats after administration of Oroxylin A.

Oroxylin A (OA), as a natural flavonoid extracted from the root of Scutellaria baicalensis Georgi, is a candidate drug with multiple pharmacological activities. However, pharmacokinetic studies of OA have rarely been reported up to now. The present study aim to conduct a systemic evaluation on the pharmacokinetics, tissue distribution and excretion of OA in rats, with quantification of both OA and its two metabolites, Oroxylin A 7-O-glucuronide (OG) and Oroxylin A sodium sulfonate (OS) by the sensitive and rapid UPLC-MS/MS methods. The results show that OA was rapidly eliminated in vivo after a single-dose (2 mg/kg) i.v. administration of OA. The relative bioavailability of OA in all three i.g. administration groups (40, 120, and 360 mg/kg) were <2%. The AUC0-t values of OA, OG, and OS in rats show an apparent dose-proportionality. OA, OG, and OS all underwent a rapid and widespread tissue distribution after i.g. administration (120 mg/kg) of OA. Except for stomach and intestine, the major distribution tissues of OA and its two metabolites in rats were liver, kidney, respectively. And OA was more widely distributed in tissue than its metabolites. After i.g. administration (120 mg/kg) of OA, it was mainly excreted from the feces, and OG mainly excreted from bile and urine, while OS almost free of excretion. This work present a comprehensive pharmacokinetics information for further investigation of OA and its two metabolites.

Oroxylin A inhibits carcinogen-induced skin tumorigenesis through inhibition of inflammation by regulating SHCBP1 in mice.

Accumulating evidence has shown that SHC SH2 domain-binding protein 1 (SHCBP1) functions as an oncogene and participated in the progression of various cancers. Oroxylin A, an active ingredient extracted from Chinese Medicine Scutellaria baicalensis, shows strong anticancer effects on multiple cancers, however, the pharmacological effect of oroxylin A on skin cancer and the regulatory effect of SHCBP1 on this process have never been evaluated. The present study was aimed at elucidating the effect of oroxylin A on carcinogen (DMBA/TPA)-induced skin tumorigenesis, and to further clarify the role of SHCBP1 in oroxylin A induced antitumor effect. Pretreatment with oroxylin A remarkably inhibited DMBA/TPA-induced tumor formation and growth, and significantly reduced tumor incidence and the average number of tumors per mouse. Oroxylin A suppressed DMBA/TPA-induced skin hyperplasia and tumor proliferation. Oroxylin A significantly inhibited the expression of several inflammatory factors in vivo. In vitro experiments found that oroxylin A inhibited TPA-induced cell malignant transformation of skin epidermal JB6 P + cells. Besides, oroxylin A significantly suppressed the levels of TPA-induced inflammatory factors in vitro. Mechanistic studies showed that oroxylin A remarkably inhibited TPA-induced increased expression of SHCBP1. Overexpression of SHCBP1 attenuated the oroxylin A-induced anti-inflammatory effect. In addition, TPA increased the expression of nuclear NF-κB p65, and SHCBP1 siRNA notably decreased the nuclear NF-κB p65 expression in JB6 P + cells. Collectively, the anti-skin cancer effect of oroxylin A may possibly by inhibiting inflammation via suppression of SHCBP1. Oroxylin A might be a potential candidate compound for the treatment of skin cancer.

Prediction and analysis of quality markers between crude and wine-processed Scutellaria baicalensis based on "components-targets-metabolism" network analysis / 中草药

Objective: To explore the potential Q-markers between crude Scutellaria baicalensis (CSR) and wine-processed S. baicalensis (WSR) based on "components-targets-metabolism" network analysis. Methods: According to the differential components between CSR and WSR, the network relationship of "components-target-metabolomics" was constructed combining network pharmacology and metabolomics. The correlation analysis was then conducted between flavonoids glycosides, and aglycones in S. baicalensis, between differential components and endogenous metabolites to predict the potential quality markers. Results: In this study, combining the results of network pharmacology and metabolomics, baicalin and oroxylin A-7-O-glucuronide were regarded as the quality markers of CSR; Baicalein and wogonin were considered as the quality markers of WSR. Conclusion: It is crucial wine-processed mechanism of S. baicalensis that glutinous rice wine can promote the dissolution and absorption of aglycones. Overall, identification of the differences between Chinese herbal decoction pieces and it processed product, combining analysis of network pharmacology and metabolomics, which provides a demonstration for the investigation of quality markers of Chinese herbal pieces.

Oroxylin A, a methylated metabolite of baicalein, exhibits a stronger inhibitory effect than baicalein on the CYP1B1-mediated carcinogenic estradiol metabolite formation.

Human cytochrome P450 1B1 (CYP1B1)-mediated formation of 4-hydroxyestradiol (4-OHE2) from 17ß-estradiol plays an important role in the progression of human breast cancer, while the biotransformation of 17ß-estradiol to 2-hydroxyestradiol mediated by cytochrome P450 1A1 (CYP1A1) is considered as a less harmful pathway. In this study, inhibitory effects of flavonoids baicalein and oroxylin A, a metabolite of baicalein in human body, on CYP1A1 and 1B1 activities were investigated in vitro. The inhibition intensities of baicalein and oroxylin A towards CYP1B1 were greater than towards CYP1A1 with a mixed mechanism. In addition, oroxylin A showed a stronger inhibitory effect than baicalein towards the CYP1B1-mediated 17ß-estradiol 4-hydroxylation, with the IC50 values of 0.0146 and 2.27 µM, respectively. Docking studies elucidated that oroxylin A had a stronger binding affinity than baicalein for CYP1B1. In MCF-7 cells, compared with baicalein-treated groups, oroxylin A with lower doses decreased and increased the formation of 4-OHE2 and 2-hydroxyestradiol, respectively, with a preferential induction of mRNA of CYP1A1 over CYP1B1. In conclusion, this study demonstrated that oroxylin A showed a stronger inhibitory effect than baicalein on CYP1B1-mediated 4-OHE2 formation in MCF-7 cells, providing crucial implications for their possibly preventive/therapeutic potential against breast cancer via inhibition of CYP1B1, particularly of oroxylin A.

Oroxylin A inhibits Kaposi's sarcoma-associated herpes virus (KSHV) vIL-6-mediated lymphatic reprogramming of vascular endothelial cells through modulating PPARγ/Prox1 axis.

BACKGROUND AND PURPOSE: Kaposi's sarcoma-associated herpes virus (KSHV) vIL-6 is sufficient to induce lymphatic reprogramming of vascular endothelial cells, which is a key event in Kaposi's sarcoma (KS) development. This study was aimed to investigate the effect of Chinese herb oroxylin A on lymphatic reprogramming and neovascularization by KSHV vIL-6 in vitro and in vivo. METHODS: The lymphatic-phenotype endothelial cell line was generated by lentiviral KSHV vIL-6 infection. Cell viability and apoptosis were determined by MTT assay or flow cytometry with annexin V/propidium iodide staining. Migration, invasion, and neovascularization of the vIL-6-expressing lymphatic-phenotype endothelial cells were determined by wound healing assay, transwell chamber assay, microtubule formation assay, and chick chorioallantoic membrane assay, respectively. Quantitative polymerase chain reaction and Western blot analysis were used to test the expression of Prox1, VEGFR3, podoplanin, LYVE-1, and PPARγ in cells. Co-localization of Prox1 and PPARγ was determined by immunofluorescence. Ubiquitination of Prox1 was detected by in vivo ubiquitination assay. RESULTS: The lymphatic-phenotype endothelial cell line expressing KSHV vIL-6 was successfully generated. Oroxylin A induced cellular invasion abrogation, apoptosis induction, and neovascularization inhibition of the vIL-6-expressing endothelial cells. Mechanically, oroxylin A elevated PPARγ expression, which in turn interacted with and facilitated Prox1 to undergo ubiquitinational degradation, and subsequently leads to VEGFR3, LYVE-1, and podoplanin reduction. CONCLUSION: Through modulating PPARγ/Prox1 axis, oroxylin A inhibits lymphatic reprogramming and neovascularization of KSHV vIL-6. Thus, oroxylin A may serve as a candidate for the treatment of KS as well as other aggressive angiomas.

Baicalin protects mice against Salmonella typhimurium infection via the modulation of both bacterial virulence and host response.

BACKGROUND: The worsening problems of antibiotic resistance prompt the need for alternative strategies. Baicalin, which is isolated from Scutellaria baicalensisi, has been demonstrated to exhibit anti-inflammatory, anti-virulence and antimicrobial effects. Salmonella typhimurium is an important foodborne pathogenic bacteriaum that causes gastrointestinal disease in humans and many animals. PURPOSE: The aim of this study was to investigate the effects of baicalin on S. typhimurium infection in mice and its possible mechanism in vitro. STUDY DESIGN: To evaluate the effect of baicalin in vivo, mice were orally administered of baicalin, and then were infected by an intragastric administration of S. typhimurium. The minimal inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of baicalin, baicalein, and oroxylin A against S. typhimurium were detected under the guides of the Clinical and Laboratory Standards Institute. In vitro, Caco-2 cells were infected with S. typhimurium in the presence or absence of baicalin, baicalein, and oroxylin A at sub-MICs. METHODS: In the in vivo experiment, the body weight loss, the serum levels of TNFα,  IL-6, and lactic dehydrogenase (LDH), the pathological changes of the caecum and the caecum bacterial burdens were examined. The MICs and MBCs of baicalin, baicalein, and oroxylin A against S. typhimurium were detected by two-fold serial dilutions. In vitro, Caco-2 cells were infected with S. typhimurium, and the invasion capacity, TNFα, nitrate, and LDH were analysed. The transcription levels of Salmonella pathogenicity island 1 virulence associated genes (sopB, sopE, sopE2) of S. typhimurium in the presence of baicalin, baicalein, and oroxylin A were detected by qRT-PCR. RESULTS: Our results showed that baicalin significantly decreased the body weight loss, the serum levels of TNFα,  IL-6, and LDH, and the caecum bacterial burdens of mice challenged with S. typhimurium. Histological examination showed that baicalin decreased the lesion in the caecum of S. typhimurium-infected mice. MICs and MBCs of baicalin, and oroxylin A. against S. typhimurium were > 128 µg/ml. MICs and MBCs of baicalein against S. typhimurium were 64 µg/ml, and > 128 µg/ml, respectively. Pretreatment of Caco-2 cells or S. typhimurium with baicalin, baicalein, and oroxylin A significantly inhibited the invasion of Caco-2 cells by S. typhimurium in a dose-dependent manner. Sub-MICs of baicalin, baicalein, and oroxylin A also significantly decreased the levels of TNFα, nitrate, and LDH from S. typhimurium-infected Caco-2 cells. Moreover, the transcription levels of sopB, sopE, and sopE2 were significantly suppressed by baicalin, baicalein, and oroxylin A. CONCLUSIONS: These results demonstrated that baicalin is a promising agent for the prevention of S. typhimurium infection via the modulation of both bacterial virulence and host response.