Amelioration of hyperglycaemia and hyperlipidaemia by adjusting the interplay between gut microbiota and bile acid metabolism: Radix Scutellariae as a case

BACKGROUND

Our previous clinical research showed that the interaction between gut microbiota and bile acids (BAs) in patients with type 2 diabetes mellitus (T2DM) changed significantly. We hypothesized that T2DM could be improved by adjusting this interaction mediated by farnesoid X receptor (FXR). T2DM belongs to the category of "xiaoke" in traditional Chinese medicine. Radix scutellariae has the effects of clearing away heat and eliminating dampness, curing jaundice and quenching thirst and is widely used alone or in combination with other medicines for the treatment of T2DM in China and throughout Asia. Additionally, the interaction between Radix scutellariae and gut microbiota may influence its efficacy in the treatment of T2DM.

PURPOSE

This study chose Radix scutellariae to validate that T2DM could improve by adjusting the interaction between gut microbiota and bile acid metabolism.

STUDY DESIGN AND METHODS

Radix scutellariae water extract (WESB) was administered to a T2DM rat model established by a high-fat diet combined with streptozotocin. The body weight and blood glucose and insulin levels were measured. The levels of serum lipids, creatinine, uric acid, albumin and total bile acid were also detected. Changes in the pathology and histology of the pancreas, liver and kidney were observed by haematoxylin-eosin staining. The 16S rRNAs of gut microbiota were sequenced, and the faecal and serum BAs were determined by liquid chromatography tandem mass spectrometry. The expression levels of BA metabolism-associated proteins in the liver and intestine were evaluated by immunoblot analysis.

RESULTS

The results showed that WESB improved hyperglycaemia, hyperlipaemia, and liver and kidney damage in T2DM rats. In addition, the abundances of key gut microbiota and the concentrations of certain secondary BAs in faeces and serum were restored. Moreover, there was a significant correlation between the restored gut microbiota and BAs, which might be related to the activation of liver cholesterol 7α-hydroxylase (CYP7A1) and the inhibition of FXR expression in the intestine rather than the liver.

CONCLUSIONS

This study provided new ideas for the prevention or treatment of clinical diabetes and its complications by adjusting the interaction between gut microbiota and bile acid metabolism.

Baicalin Protects Against Acute Pancreatitis Involving JNK Signaling Pathway via Regulating miR-15a

Acute pancreatitis (AP) is a kind of reversible inflammatory process of the exocrine pancreas. During the process, systemic inflammatory syndromes are involved, which relates closely to inflammatory mediators. Baicalin is a type of flavone compound extracted from Scutellaria baicalensis Georgi and exhibits anti-inflammation effect in several cancers. In this study, baicalin displayed a suppressing role on IL-1[Formula: see text], TNF[Formula: see text] and IL-6 in both cell and mice models. Necrosis was decreased in the baicalin treatment group and got a markedly lower pathological score. In this study, miR-15a is the core intermediate in baicalin regulation, which increased through baicalin treatment and protected pancreas cells and tissues, inhibiting the JNK signaling pathway by targeting MAP2K4. The long non-coding RNA MALAT1 is also a direct target of miR-15a and forms a competitive endogenous RNA (ceRNA) network with MAP2K4, which can be regulated by baicalin. In addition, upstream genes, including CDC42 and MAP3K1, were also regulated by baicalin, of which CDC42 was confirmed to form the second ceRNA network with MALAT1 and miR-15a. In conclusion, baicalin exhibits therapeutic activity towards AP by pumping up miR-15a level and inhibiting CDC42/MAP3K1, which affects AP as a brake by targeting MAP2K4 and inhibiting the JNK signaling pathway.

An integrated strategy for profiling the chemical components of Scutellariae Radix and their exogenous substances in rats by ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry

RATIONALE

Traditional Chinese medicines (TCMs) attract worldwide attention because of their effects in clinical application recorded in China historical ancient codes and in records, such as 'Treatise on Febrile Diseases'. With the developments of drug analysis and research, evaluating the in vivo substances in TCMs has become of great importance. Scutellariae Radix (SR, named as huang-qing in China), the root of Scutellaria baicalensis Georgi, has shown favorable clinical effects and safety in the treatment of infection diseases; however, its in vivo compounds are unclear and need detailed investigation.

METHODS

An ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC/QTOF MS) method coupled to an integrated strategy involving diagnostic ions, neutral losses and a prediction platform was used to explore the constituents of SR, and their exogenous substances in rats.

RESULTS

A total of 118 chemical constituents mainly featuring five chemical structure types (flavone C-glycosides, flavone O-glycosides, free flavones, flavanones and phenylethanoid glycosides) were identified or tentatively characterized in SR, and 175 xenobiotics (68 prototypes and 107 metabolites) were profiled in rat plasma, urine, bile and feces after ingestion of SR. The metabolites were classified into four related chemical groups: flavone C-glycosides, flavone O-glycosides, flavanones and phenylethanoid glycosides. Phase II metabolism reactions, such as glucuronidation and sulfation, were the major metabolic reactions in addition to phase I reactions of hydrolysis and hydrogenation. The corresponding main metabolic features of SR in rats were also elucidated.

CONCLUSIONS

The metabolism of SR, as a whole, was systemically revealed for the first time, and our work also provided meaningful information for pharmacokinetics studies and pharmacological analysis of SR in future work.

Herbal pair Huangqin-Baishao: mechanisms underlying inflammatory bowel disease by combined system pharmacology and cell experiment approach

BACKGROUND

Inflammatory bowel disease (IBD) is a severe digestive system condition, characterized by chronic and relapsing inflammation of the gastrointestinal tract. Scutellaria baicalensis Georgi (Huangqin, HQ) and Paeonia lactiflora Pall (Baishao, BS) from a typical herbal synergic pair in traditional Chinese medicine (TCM) for IBD treatments. However, the mechanisms of action for the synergy are still unclear. Therefore, this paper aimed to predict the anti-IBD targets and the main active ingredients of the HQ-BS herbal pair.

METHODS

A systems pharmacology approach was used to identify the bioactive compounds and to delineate the molecular targets and potential pathways of HQ-BS herbal pair. Then, the characteristics of the candidates were analyzed according to their oral bioavailability and drug-likeness indices. Finally, gene enrichment analysis with DAVID Bioinformatics Resources was performed to identify the potential pathways associated with the candidate targets.

RESULTS

The results showed that, a total of 38 active compounds were obtained from HQ-BS herbal pair, and 54 targets associated with IBD were identified. Gene Ontology and pathway enrichment analysis yielded the top 20 significant results with 54 targets. Furthermore, the integrated IBD pathway revealed that the HQ-BS herbal pair probably acted in patients with IBD through multiple mechanisms of regulation of the nitric oxide biosynthetic process and anti-inflammatory effects. In addition, cell experiments were carried out to verify that the HQ-BS herbal pair and their Q-markers could attenuate the levels of nitric oxide (NO), prostaglandin E2 (PGE2), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in lipopolysaccharide (LPS)-stimulated THP-1-derived macrophage inflammation. In particular, the crude materials exerted a much better anti-inflammatory effect than their Q-markers, which might be due to their synergistic effect.

CONCLUSION

This study provides novel insight into the molecular pathways involved in the mechanisms of the HQ-BS herbal pair acting on IBD.

Complexity of active medicinal ingredients in radix scutellariae with sodium hydrosulfite exposure

Both plants and animals are living things made up of similar cells as well as organelles, and their essence of life is the same. However, plants face more environmental stress than animals and generate excessive reactive oxygen species (ROS), a group of small molecules that can harm proteins, necessitating distinctive metabolic processes. Secondary metabolites in plants are a group of chemical components that can eliminate ROS and can also exhibit medicinal properties; therefore, herbal medicines are often closely linked to the ecological significance of secondary metabolites. Why plants contain so many, not few, active medicinal ingredients is unknown. The root of Scutellaria baicalensis, a popular herbal medicine, is rich in various flavonoids with diverse structural features. Sodium hydrosulfite (Na₂S₂O₄) can produce O˙^-₂ radicals and induce physical conditions under environmental stress. Using UHPLC-ESI-Q-TOF-MS/MS analysis, a total of 25 different compounds were identified in the roots of S. baicalensis between the Na₂S₂O₄ groups and suitable conditions. Based on the results of the t-test (P<0.05) performed for the groups and ions with values of VIP ≥ 2, the most significantly different chemical markers with Na₂S₂O₄ treatment were shikimic acid, citric acid, baicalin, wogonoside, baicalein, wogonin, 3,5,7,2',6'-pentahydroxyflavanone, 5,2',6'-trihydroxy-7,8-dimethoxy flavone, chrysin, eriodictyol, 5,8-dihydroxy-6,7 -dimethoxy flavone, skullcapflavone Ⅱ, and 5,7-dihydroxy-6,8,2',3'-tetrame thoxyflavone, and most of them were free flavonoids with many phenolic hydroxyl or methoxyl groups and characteristically high antioxidant activities. S. baicalensis roots modified their ability to eliminate ROS and maintained the equilibrium of ROS through the multitudinous biosynthesis and conversion of flavonoids, which is similar to the equilibrium established by an intricate buffer solution and perfectly explains the diversity and complexity of medicinal plant ingredients.

Oroxyloside ameliorates acetaminophen-induced hepatotoxicity by inhibiting JNK related apoptosis and necroptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Oroxyloside is a natural flavonoid isolated from Scutellaria baicalensis Georgi (Lamiaceae) which is a Chinese herb widely used for liver diseases. However, its mechanisms on protecting against drug induced liver injury has not been investigated yet.

AIM OF THE STUDY

To investigate the protecting effects and the primary mechanisms of oroxyloside on acetaminophen (APAP)-induced liver injury.

MATERIALS AND METHODS

After a 12 h fasting period with free access to water, C57BL/6 mice were injected with APAP (300 mg/kg) intragastrically (i.g.) and 1 h later with oroxyloside (100 mg/kg, i.g.). When mice sacrificed, blood samples were collected from fundus venous plexus and liver tissues were collected. In addition, cells were incubated with 10 mM APAP alone and 10 mM APAP combined with 100 μM oroxyloside for 24 h. ELISA, TUNEL assay, qRT-PCR et al. were used to assess the effect of oroxyloside on ameliorating APAP-induced hepatotoxicity in vitro and in vivo. Western bolt and immunohistochemistry were used in the signaling pathway analysis.

RESULTS

Oroxyloside administration significantly decreased the accumulations of CYP2E1, CYP1A2, IL-6, IL-1β, ALT and AST induced by APAP in vivo. In addition, oroxyloside inhibited the APAP-induced JNK related apoptosis by enhancing the antioxidant defenses, reversing ER-stress and keeping the mito-balance of liver cells in vivo and in vitro. Furthermore, oroxyloside protected the liver cells from necroptosis by affecting JNK pathway.

CONCLUSION

Oroxyloside acted as a protective agent against APAP-induced liver injury through inhibiting JNK-related apoptosis and necroptosis.

Characterization of Anti-Inflammatory and Antioxidant Constituents from Scutellaria baicalensis Using LC-MS Coupled with a Bioassay Method

An effective and previously demonstrated screening method for active constituents in natural products using LC-MS coupled with a bioassay was reported in our earlier studies. With this, the current investigation attempted to identify bioactive constituents of Scutellaria baicalensis through LC-MS coupled with a bioassay. Peaks at broadly 17-20 and 24-25 min on the MS chromatogram displayed an inhibitory effect on NO production in lipopolysaccharide-induced BV2 microglia cells. Similarly, peaks at roughly 17-19 and 22 min showed antioxidant activity with an 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS)/2,2-diphenyl-1- picrylhydrazyl (DPPH) assay. For confirmation of LC-MS coupled with a bioassay, nine compounds (1-9) were isolated from an MeOH extract of S. baicalensis. As we predicted, compounds 1, 8, and 9 significantly reduced lipopolysaccharide (LPS)-induced NO production in BV2 cells. Likewise, compounds 5, 6, and 8 exhibited free radical-scavenging activities with the ABTS/DPPH assay. In addition, the structural similarity of the main components was confirmed by analyzing the total extract and EtOAc fractions through molecular networking. Overall, the results suggest that the method comprised of LC-MS coupled with a bioassay can effectively predict active compounds without an isolation process, and the results of molecular networking predicted that other components around the active compound node may also be active.

The effect of baicalein on Wnt/β-catenin pathway and miR-25 expression in Saos-2 osteosarcoma cell line

Background/aim

Osteosarcoma is the most common primary bone malignancy that occurs frequently in children and adolescents. Baicalein, a flavonoid that has attracted great attention in recent years with its strong antitumor activity, shows a wide range of biological and pharmaceutical effects.MicroRNAs have been found to be involved in many critical processes in cancers. This study aimed to investigate the effect of baicalein and miR-25 on Wnt/β-catenin signaling pathway of osteosarcoma cell line Saos-2.

Materials and methods

Cell viability was assessed, and qRT-PCR and Western blot were performed to study the effects of baicalein on expression of Wnt/β-catenin signaling pathway-realted genes (β-catenin, GSK-3β, and Axin2) of Saos-2 cells.

Results

Our results indicated that baicalein can inhibit the proliferation (IC50 value 35 μM), regulate Wnt/β-catenin pathway and also increase miR-25 expression of Saos-2. Baicalein and also miR-25 decreased the expression of β-catenin and Axin2, while increasing the expression of GSK-3β. Down regulation of miR-25 decreased the expression of GSK-3β, while β-catenin and Axin2 expression increased.

Conclusion

These findings demonstrate that baicalein may target genes related to the Wnt/β-catenin pathway by regulating miR-25 expression and may be a potential Wnt/β-catenin pathway inhibitor for osteosarcoma therapy.

A systematic analysis of natural α-glucosidase inhibitors from flavonoids of Radix scutellariae using ultrafiltration UPLC-TripleTOF-MS/MS and network pharmacology

BACKGROUND

Flavonoids from plant medicines are supposed to be viable alternatives for the treatment of type 2 diabetes (T2D) as less toxicity and side effects. Radix scutellariae (RS) is a widely used traditional medicine in Asia. It has shown great potential in the research of T2D. However, the pharmacological actions remain obscured due to the complex chemical nature of plant medicines.

METHODS

In the present study, a systematic method combining ultrafiltration UPLC-TripleTOF-MS/MS and network pharmacology was developed to screen α-glucosidase inhibitors from flavonoids of RS, and explore the underlying mechanism for the treatment of T2D.

RESULTS

The n-butanol part of ethanol extract from RS showed a strong α-glucosidase inhibition activity (90.55%, IC50 0.551 mg/mL) against positive control acarbose (90.59%, IC50 1.079 mg/mL). A total of 32 kinds of flavonoids were identified from the extract, and their ESI-MS/MS behaviors were elucidated. Thirteen compounds were screened as α-glucosidase inhibitors, including viscidulin III, 2',3,5,6',7-pentahydroxyflavanone, and so on. A compound-target-pathway (CTP) network was constructed by integrating these α-glucosidase inhibitors, target proteins, and related pathways. This network exhibited an uneven distribution and approximate scale-free property. Chrysin (k = 87), 5,8,2'-trihydroxy-7-methoxyflavone (k = 21) and wogonin (k = 20) were selected as the main active constituents with much higher degree values. A protein-protein interaction (PPI) weighted network was built for target proteins of these α-glucosidase inhibitors and drug targets of T2D. PPARG (Cd = 0.165, Cb = 0.232, Cc = 0.401), ACACB (Cd = 0.155, Cb = 0.184, Cc = 0.318), NFKB1 (Cd = 0.233, Cb = 0.161, Cc = 0.431), and PGH2 (Cd = 0.194, Cb = 0.157, Cc = 0.427) exhibited as key targets with the highest scores of centrality indices. Furthermore, a core subnetwork was extracted from the CTP and PPI weighted network. Type II diabetes mellitus (hsa04930) and PPAR signaling pathway (hsa03320) were confirmed as the critical pathways.

CONCLUSIONS

These results improved current understanding of natural flavonoids on the treatment of T2D. The combination of ultrafiltration UPLC-TripleTOF-MS/MS and network pharmacology provides a novel strategy for the research of plant medicines and complex diseases.

Natural Deep Eutectic Solvent Extraction of Flavonoids of Scutellaria baicalensis as a Replacement for Conventional Organic Solvents

Natural deep eutectic solvents (NADES) are a type of ionic liquid (IL) or deep eutectic solvent (DES), the ingredients of which are exclusively natural products (non-toxic and environmentally friendly). Here, we explore the potential of NADES as an alternative to conventional organic solvents (e.g., aqueous methanol or ethanol) for the extraction of flavonoids from Scutellaria baicalensis stem bark to investigate their extractability depending on structural variation. Four NADES, each containing citric acid in combination with β-alanine, glucose, xylitol, or proline (at a molar ratio of 1:1), and a variable amount of water, were used to extract the flavonoid aglycones: baicalein (1), scutellarein (3), wogonin (5), and oroxylin A (7), and their glycosides, baicalin (2), scutellarin (4), wogonoside (6) and oroxyloside (8) from the powdered bark of S. baicalensis. The chemical profile and yield of the extracts were determined using HPTLC and HPLC. The extractability of individual flavonoids was found to be influenced by the concentration of water (20-60%, w/w) in the NADES. Among the tested flavonoids, the extraction yield of baicalein (1), scutellarein (3), wogonin (5), oroxylin A (7) with NADES was 2 to 6 times that of aqueous methanol. However, the amount of their corresponding glycosides (baicalin (2), wogonoside (6) and oroxyloside (8)) extracted with NADES was only 1.5-1.8 times higher than with aqueous methanol. Interestingly, the more hydrophilic glycosides were less extracted than their corresponding aglycones despite the high hydrophilicity of the NADES. These results prove that NADES may be used for extraction of compounds with a wide range of hydrophilicity.

Online coupling of the Ussing chamber, solid-phase extraction and high-performance liquid chromatography for screening and analysis of active constituents of traditional Chinese medicines

A semi-automated online platform was established successfully for preliminary screening of potential active flavonoids of traditional Chinese medicines (TCMs) in multicomponent system. Online coupling of the in vitro intestinal absorption model, solid phase extraction (SPE) and high-performance liquid chromatography (HPLC) was actualized at the first time. The Ussing chamber model was selected to absorb the constituents of TCMs. A mini chromatographic column filled with C18 was used as a SPE column for online enrichment of flavonoids. HPLC was applied to analyze the constituents screened by platform. With the use of rutin as a model flavonoid, the specifications of SPE column, eluting solvent, elution time and flow rate of eluent were systematically investigated to optimize online system. Under the optimal conditions, the linear range of rutin was 0.125-368 µg/mL with the correlation coefficient (R²) greater than 0.9947. The limit of detection (LOD) was as low as 0.0500 µg/mL and the limit of quantification (LOQ) was 0.125 µg/mL. The intra-day relative standard deviation (RSD) and inter-day RSD was 2.5% and 3.8%, respectively. The recoveries of rutin in the intestinal absorption samples ranged from 93.2% to 94.0%. Finally, the online system was applied to screen the potential active flavonoids of Scutellaria baicalensis Georgi (Huangqin, HQ) and Polygoni Cuspidati Rhizoma et Radix (Huzhang, HZ). A total of 14 flavonoids of these two TCMs were identified by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), and 12 flavonoids of them were screened as the potential active components by online Ussing chamber-SPE-HPLC. In comparison with offline method and gavage in rats, the online system can screen the active constituents from TCMs more accurately and completely. The results demonstrated that the online system was reliable and sufficiently accurate for screening and determination of the potential active flavonoids of TCMs in multicomponent system.

A Systems Pharmacology Approach Uncovers Wogonoside as an Angiogenesis Inhibitor of Triple-Negative Breast Cancer by Targeting Hedgehog Signaling

Triple-negative breast cancer (TNBC) is an aggressive and heterogeneous disease that lacks clinically actionable genetic alterations that limit targeted therapies. Here we explore a systems pharmacology approach that integrates drug-target networks and large-scale genomic profiles of TNBC and identify wogonoside, one of the major active flavonoids, as a potent angiogenesis inhibitor. We validate that wogonoside attenuates cell migration, tube formation, and rat aorta microvessel outgrowth, and reduces formation of blood vessels in chicken chorioallantoic membrane and TNBC cell-induced Matrigel plugs. In addition, wogonoside inhibits growth and angiogenesis in TNBC cell xenograft models. This network-based approach predicts, and we empirically validate, wogonoside's antiangiogenic effects resulting from vascular endothelial growth factor secretion. Mechanistically, wogonoside inhibits Gli1 nuclear translocation and transcriptional activities associated with Hedgehog signaling, by promoting Smoothened degradation in a proteasome-dependent mechanism. This study offers a powerful, integrated, systems pharmacology-based strategy for oncological drug discovery and identifies wogonoside as a potential TNBC angiogenesis inhibitor.

Near infrared system coupled chemometric algorithms for the variable selection and prediction of baicalin in three different processes

Characteristic variables are essential and necessary basis in model construction, and are related to the prediction result closely in near infrared spectroscopy (NIRS) analysis. However, the same compound usually has different characteristic variables for different analysis and it would be lower correlation between variables and structure in many researches. So, the accuracy and reliability are expected to improve by exploring characteristic variables in different spectrum analysis. In this study, competitive adaptive weighted resampling method (CARS) was applied to select characteristic variables related to baicalin from NIRS analysis data, which were applied to analysis of baicalin in three different processes including the herb, extraction process and concentration process of Scutellaria baicalensis. After application of CARS method, 70, 50 and 50 variables were selected respectively from three processes above. The selected variables were firstly analyzed by statistical methods that they were found to be consistent and correlated among three different processes after one-way analysis of variance test and Kendall's W. Partial least-squares (PLS) regression and extreme learning machine (ELM) models were constructed based on optimized data. Models after variable selection were less complicated and had better prediction results than global models. After comparison, CARS-PLS was suitable for the prediction of extraction process, while for the concentration process and herb, CARS-ELM performed better. The Rc value of the herb, extraction and concentration model were 0.9469, 0.9841 and 0.9675, respectively. The RSEP values were 4.54%, 6.96% and 8.37%, respectively. The results help to frame a theoretical basis for characteristic variables of baicalin.

Comparative Investigation for Rotten Xylem (kuqin) and Strip Types (tiaoqin) of Scutellaria baicalensis Georgi Based on Fingerprinting and Chemical Pattern Recognition

Scutellaria baicalensis Georgi (SBG) is not just as a traditional herbal medicine but also a popular functional food in China and other Asian countries. A sensitive simple strategy was developed for the first time to analyze SBG from eight different geographical sources using high-performance liquid chromatography (HPLC) coupled with multivariate chemometric methods. Two unsupervised pattern recognition models, hierarchical cluster analysis (HCA) and principal components analysis (PCA), and a supervised pattern recognition model, partial least squares discriminant analysis (PLS-DA), were used to analyze the chemical compositions and physical traits of SBG. The important chemical markers baicalin, baicalein, and wogonoside were analyzed quantitatively and with PLS-DA. These methods distinguished rotten xylem (kuqin) and strip types (tiaoqin) of SBG and found that the thickness of the slice had a significant impact on the classification of SBG. Two classes of strip types were identified: one as the uncut pharmaceutical, which was sectioned with a thickness >3 mm; the other as a thin-sectioned strip type, with a thickness of <2 mm. This fingerprinting technique coupled to a chemometric analysis was used for the simultaneous quantitation of three components (chemical markers) of SBG, and greatly simplified the complicated identification of the multiple components of this plant relative to traditional methods. The strategy can clearly distinguish between kuqin and tiaoqin of SBG, and suggests that the thickness of the slice can be used as the basis for evaluation of SBG. These data provide a theoretical basis and scientific evidence for the development and utilization of SBG.

Inhibitory Effects of Scutellaria baicalensis Root Extract on Linoleic Acid Hydroperoxide-induced Lung Mitochondrial Lipid Peroxidation and Antioxidant Activities

In this study, we evaluated the ability of Scutellaria baicalensis Georgi to protect lipid-peroxidation (LPO) in lung tissue after free radical-induced injury. We prepared S. baicalensis root (SBR) extracts using different solvents. The total flavonoid and total phenol contents of each extract were measured, and the ROS damage protection was evaluated by analyzing linoleic acid hydroperoxide (LHP)-induced LPO in rat lung mitochondria. Moreover, evaluating diphenylpicrylhydrazyl (DPPH), hydrogen peroxide, superoxide anion radical, and hydroxyl radical scavenging abilities and using metal chelating assays were used to determine in vitro antioxidant activity. The ethyl acetate (EtOAc) extract showed high ROS scavenging ability, and four compounds were subsequently isolated and purified from this extract: baicalin, baicalein, wogonin, and oroxylin A. Baicalein in rat lung mitochondria the most significant LHP-induced LPO inhibition was shown and extracted with EtOAc that contained the highest amount of baicalein. Thus, baicalein and the EtOAc extract of SBR may be efficient in conferring ROS damage protection and inhibiting LHP-induced LPO in rat lung mitochondria. Additional studies are warranted to investigate their use as antioxidant therapy for respiration infections, nutrition supplements, and lead compounds in pharmaceuticals.

Total flavonoid aglycones extract in Radix Scutellariae induces cross-regulation between autophagy and apoptosis in pancreatic cancer cells

ETHNOPHARMACOLOGICAL RELEVANCE

Radix Scutellariae (RS), the dried root of Scutellariae baicalensis Georgi, known as a herbal medicine in several Asian countries including China, has been widely used to treat inflammation, hypertension, cardiovascular disease as well as cancer. The total flavonoid aglycone extracted (TFAE) was extracted by ethyl acetate and this extraction methodology was optimized and obtained the protection of Chinese patents.

AIM OF THE STUDY

To investigate the underlying mechanism of the chemotherapeutic effects of TFAE in inducing autophagy and apoptosis in pancreatic cancer cells in vitro and in vivo.

MATERIALS AND METHODS

We performed CCK8 assays, AnnexinV-FITC/PI staining, flow cytometry assays, transmission electron microscopy, immunofluorescence analysis and Western blot to study the molecular mechanism of TFAE in inducing autophagy and apoptosis in pancreatic cancer cells in vitro and in vivo.

RESULTS

In vitro, TFAE exhibits significant anti-tumor activity against pancreatic cancer cell lines, especially for BxPC3 (IC₅₀ = 6.5 μg mL^-1). Moreover, TFAE induces apoptosis and autophagy as evidenced by the increased apoptosis or autophagy-related protein level, the increased the fraction of apoptotic cells and the punctuate patterns of LC3 II. Furthermore, TFAE induce autophagy through PI3K/Akt/mTOR inhibition. Interestingly, pharmacological block autophagy by 3-MA enhanced TFAE-induced apoptosis, indicating that TFAE induced autophagy functions as a cytoprotective process against apoptosis. In vivo, 150 mg/kg TFAE inhibited the BxPC3 tumor growth in immune deficient mice with the inhibitory rate of 66.87% and induced both apoptosis and autophagy.

CONCLUSION

TFAE have anti-tumor activity against pancreatic cancer and can induce apoptosis and autophagy through PI3K/Akt/mTOR signal pathway. TFAE might be a potential anticancer drug to be further developed for human pancreatic cancer therapy.

In vivo effect of quantified flavonoids-enriched extract of Scutellaria baicalensis root on acute lung injury induced by influenza A virus

BACKGROUND

Scutellaria baicalensis root is traditionally used for the treatment of common cold, fever and influenza. Flavonoids are the major chemical components of S. baicalensis root.

PURPOSE

To evaluate the therapeutic effects and action mechanism of flavonoids-enriched extract from S. baicalensis root (FESR) on acute lung injury (ALI) induced by influenza A virus (IAV) in mice.

METHODS

The anti-influenza, anti-inflammatory and anti-complementary properties of FESR and the main flavonoids were evaluated in vitro. Mice were challenged intranasally with influenza virus H1N1 (A/FM/1/47) 2  h before treatment. FESR (50, 100 and 200  mg/kg) was administrated intragastrically. Baicalin (BG), the most abundant compound in FESR was given as reference control. Survival rates, life spans and lung indexes of IAV-infected mice were measured. Histopathological changes, virus levels, inflammatory markers and complement deposition in lungs were analyzed.

RESULT

Compared with the main compound BG, FESR and lower content aglycones (baicalein, oroxylin A, wogonin and chrysin) in FESR significantly inhibited H1N1 activity in virus-infected Madin-Darby canine kidney (MDCK) cells and markedly decreased nitric oxide (NO) production from lipopolysaccharide (LPS)-stimulated RAW264.7 cells. In vitro assays showed that FESR and BG had no anti-complementary activity whereas baicalein, oroxylin A, wogonin and chrysin exhibited obvious anti-complementary activity. Oral administration of FESR effectively protected the IAV-infected mice, increased the survival rate (FESR: 67%; BG: 33%), decreased the lung index (FESR: 0.90; BG: 1.00) and improved the lung morphology in comparing with BG group. FESR efficiently decreased lung virus titers, reduced haemagglutinin (HA) titers and inhibited neuraminidase (NA) activities in lungs of IAV-infected mice. FESR modulated the inflammatory responses by decreasing the levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and monocyte chemotactic protein-1 (MCP-1), and increasing the levels of interferon-γ (IFN-γ) and interleukin-10 (IL-10) in lung tissues. Although showing no anti-complementary activity in vitro, FESR obviously reduced complement deposition and decreased complement activation product level in the lung .

CONCLUSION

FESR has a great potential for the treatment of ALI induced by IAV and the underlying action mechanism might be closely associated with antiviral, anti-inflammatory and anti-complementary properties. Furthermore, FESR resulted in more potent therapeutic effect than BG in the treatment of IAV-induced ALI.

Scutellaria baicalensis Alleviates Insulin Resistance in Diet-Induced Obese Mice by Modulating Inflammation

Insulin resistance is strongly associated with the metabolic syndrome, and chronic inflammation is known to be a major mechanism of insulin resistance and is a therapeutic target. This study was designed to evaluate the effect of Scutellaria baicalensis (SB) in high-fat diet (HFD)-induced insulin-resistant mice and to investigate its mechanism based on inflammatory responses. Mice were fed a HFD to induce insulin resistance and then administered SB for nine weeks. Body weight, glucose, lipid, insulin, epididymal fat pad and liver weights, and histologic characteristics were evaluated to determine the effect on insulin resistance. In order to evaluate the effects on the inflammatory process, we analyzed the proportions of macrophages in liver and epididymal fat and measured inflammatory gene expression. Fasting and postprandial glucose, fasting insulin, HOMA-IR, triglycerides, and low density lipoprotein cholesterol levels were significantly decreased by SB administration. The epididymal fat and liver showed significant weight decreases and histological improvements. Total adipose tissue macrophages (ATMs) decreased (27.71 ± 3.47% vs. 45.26 ± 7.26%, p < 0.05), M2 ATMs increased (47.02 ± 6.63% vs. 24.28 ± 8.00%, p < 0.05), and CD11b⁺ Kupffer cells decreased. The expression levels of tumor necrosis factor alpha and F4/80 in the liver were significantly decreased (12.03 ± 1.47% vs. 25.88 ± 4.57%, p < 0.05) compared to HFD group. These results suggest that SB improved insulin resistance through inhibition of macrophage-mediated inflammation.

7-O-Methylwogonin from Scutellaria baicalensis Disturbs Mitotic Progression by Inhibiting Plk1 Activity in Hep3B Cells

Polo-like kinase 1, a mitotic Ser/Thr kinase, has emerged as a molecular target for the development of anticancer drugs. In this study, we found that polo-like kinase 1 activity was inhibited by 7-O-methylwogonin and related flavones, including baicalein, dihydrobaicalein, and viscidulin II, isolated from Scutellaria baicalensis. Although dihydrobaicalein exhibited the highest polo-like kinase 1 inhibitory activity among the four compounds, it also inhibited other kinases, such as vaccinia-related kinase 2 and polo-like kinase 2. Baicalein and viscidulin II also showed low selectivity to polo-like kinase 1 since they inhibited polo-like kinase 3 and polo-like kinase 2, respectively. However, 7-O-methylwogonin exhibited selective polo-like kinase 1 inhibitory activity, as evidenced from in vitro kinase assays based on fluorescence resonance energy transfer assays and ADP-Glo kinase assays. In addition, examination of mitotic morphology and immunostaining using specific antibodies for the mitotic markers, p-histone H3 and mitotic protein monoclonal 2, in Hep3B cells showed that 7-O-methylwogonin treatment increased mitotic cell populations due to inhibition of mitotic progression as a result of polo-like kinase 1 inhibition. The pattern of 7-O-methylwogonin-induced mitotic arrest was similar to that of BI 2536, a specific polo-like kinase 1 inhibitor. Thus, it was suggested that 7-O-methylwogonin disturbed mitotic progression by inhibiting polo-like kinase 1 activity. These data suggest that 7-O-methylwogonin, a polo-like kinase 1 inhibitor, may be a useful anticancer agent because of its polo-like kinase 1 selectivity and effectiveness.

Rapid and Simultaneous Determination of Three Active Components in Raw and Processed Root Samples of Scutellaria baicalensis by Near-infrared Spectroscopy

Motivated by the wide use of Scutellariae Radix (SR) in the food and pharmaceutical industries, a rapid and non-destructive near-infrared spectroscopy (NIRS) method was developed for the simultaneous analysis of three main active components in raw SR and SR processed by stir-frying with wine. From seven geographical areas, 58 samples were collected. The reference contents for the SR components baicalin, baicalein, and wogonin were determined by high-performance liquid chromatography. Two multivariate analysis methods, partial least-squares (PLS) regression as a linear regression method and artificial neural networks (ANN) as a nonlinear regression method, were applied to the NIR data, and their results were compared. In the PLS model, different model parameters (i.e., 11 spectral pre-treatment methods), spectral region, and latent variables were investigated to optimize the calibration model; additionally, the ANN model was applied with five different spectral pre-treatment methods and six algorithms. For the optimal model parameters, the correlation coefficients of the calibration set for baicalin, baicalein, and wogonin were 0.9979, 0.9786, and 0.9773, respectively; the correlation coefficients of the prediction set were 0.9756, 0.9843, and 0.9592, respectively; the root mean square error of validation values were 0.215, 0.321, and 0.174, respectively. The optimal NIR models were then employed to analyze the effects of processing and geographical regions on analyte contents. The established NIR methods were robust, accurate, and reproducible. NIRS may be a promising approach for the routine screening and quality control of traditional Chinese medicines.

Deep Eutectic Solvent-Based Ultrahigh Pressure Extraction of Baicalin from Scutellaria baicalensis Georgi

Deep eutectic solvents (DESs), promising green solvents, and ultrahigh pressure extraction (UPE) as an effective auxiliary extraction method, have attracted wide attention. In this study, DES was coupled with UPE to efficiently extract baicalin from Scutellaria baicalensis Georgi. First, choline chloride: lactic acid (ChCl-LA, molar ratio 1:1) was selected as the most appropriate DES by comparing the extraction yield of different DESs. Second, the extraction protocol was optimized by response surface methodology (RSM) considering the impacts of ChCl-LA concentration, extraction pressure, extraction time and liquid-solid ratio on the extraction yield. Under the optimal condition (40 vol% water content, extraction pressure of 400 MPa, extraction time of 4 min and a liquid-solid ratio of 110 mL/g), a maximum yield of 116.8 mg/g was achieved, higher than that obtained by the traditional extraction method. The microstructure of the raw and extracted Scutellaria baicalensis Georgi samples according to scanning electron microscope (SEM) images revealed that the dissolution of chemical components was enhanced from the disrupted root tissues after DESs-UPE. DESs coupled with UPE could effectively extract the baicalin from Scutellaria baicalensis Georgi as a rapid and efficient extraction method.

Active compounds present inRosmarinus officinalis leaves andScutellaria baicalensis root evaluated as new therapeutic agents for endometriosis

RESEARCH QUESTION

Can carnosic acid, (CA) rosmarinic acid (RA) and wogonin (WG) inhibit the growth of cultured human endometrial stromal cells and endometriotic-like lesions induced in a BALB/c model of endometriosis?

DESIGN

Primary stromal cell cultures were established from endometrial biopsies from women with endometriosis and controls. The human endometrial stromal cell line T-HESC was also used for in-vitro experiments. Endometriosis was surgically induced in BALB/c mice, which were randomly assigned to CA 2 mg/kg/day (n = 11); CA 20 mg/kg/day (n = 10); RA 1 mg/kg/day (n = 11); RA 3 mg/kg/day (n = 10); WG 20 mg/kg/day (n = 12); intraperitoneal vehicle control (n = 8) or oral vehicle control (n = 11). After surgery, CA and RA were administered intraperitoneally on days 14-28. WG was administered orally by intragastric gavage on days 14-26.

RESULTS

CA, RA and WG significantly inhibited in-vitro cell proliferation in primary and T-HESC cell cultures (P < 0.05). CA and WG induced cell cycle arrest of T-HESC at the G2/M phase (P < 0.01). RA reduced intracellular ROS accumulation (P < 0.001), whereas WG increased it (P < 0.05). WG significantly inhibited oestrogen receptor alpha expression in T-HESC (P < 0.01). In-vivo, CA, RA and WG significantly reduced lesions size (P < 0.05). All compounds significantly decreased the percentage of cells in proliferation (P < 0.05) whereas RA and WG further increased the percentage of apoptotic cells (P < 0.05) in endometriotic-like lesions.

CONCLUSIONS

The results are promising; further investigation of these compounds as new therapeutics is needed.

Baicalein protects human vitiligo melanocytes from oxidative stress through activation of NF-E2-related factor2 (Nrf2) signaling pathway

Vitiligo is a complex disorder characterized by patchy loss of skin pigmentation due to abnormal melanocyte function. Overwhelming evidences have suggested that oxidative stress plays a major role in the loss of melanocytes thereby mediating the onset and progression of vitiligo. The nuclear factor erythroid 2-like factor 2 (Nrf2) is a master regulator of cellular redox homeostasis and the activation of Nrf2 signaling pathway is impaired in the vitiligo melanocytes. Baicalein, as flavonoid extracted from the Scutellaria baicalensis, has been proved to possess the ability to activate Nrf2 signaling pathway in other cell types and mouse model. Our previous data found that baicalein exerts a cytoprotective role in H₂O₂-induced apoptosis in human melanocytes cell line (PIG1). Based on these founding, we hypothesized that baicalein activates Nrf2 signaling pathway, alleviates H₂O₂-induced mitochondrial dysfunction and cellular damage, thereby protecting human vitiligo melanocytes from oxidative stress. In the present study, we found that baicalein effectively inhibited H₂O₂-induced cytotoxicity and apoptosis in human vitiligo melanocytes (PIG3V). Further results demonstrated that baicalein promoted Nrf2 nucleus translocation as well as up-regulated the expression of Nrf2 and its target gene, heme oxygenase-1 (HO-1). Moreover, the protective effects of baicalein against H₂O₂-induced cellular damage and apoptosis as well as mitochondrial dysfunction were abolished by Nrf2 knockdown. Additionally, we observed that Nrf2 knockdown suppressed proliferation and increased the sensitivity of PIG3V cells to H₂O₂ treatment. Finally, we explored the mechanism of baicalein associated with Nrf2 activation and found that the phosphorylation of Nrf2 as well as ERK1/2and PI3K/AKT signaling were not involved in the baicalein-induced activation of Nrf2. Taken together, these data clearly suggest that baicalein enhances cellular antioxidant defense capacity of human vitiligo melanocytes through the activation of the Nrf2 signaling pathway, providing beneficial evidence for the application of baicalein in the vitiligo treatment.

Scutellariae Radix and Coptidis Rhizoma Improve Glucose and Lipid Metabolism in T2DM Rats via Regulation of the Metabolic Profiling and MAPK/PI3K/Akt Signaling Pathway

Aim Scutellariae Radix (SR) and Coptidis Rhizoma (CR) have often been combined to cure type 2 diabetes mellitus (T2DM) in the clinical practice for over thousands of years, but their compatibility mechanism is not clear. Mitogen-activated protein kinase (MAPK) signaling pathway has been suggested to play a critical role during the process of inflammation, insulin resistance, and T2DM. This study was designed to investigate their compatibility effects on T2DM rats and explore the underlying mechanisms by analyzing the metabolic profiling and MAPK/PI3K/Akt signaling pathway. Methods The compatibility effects of SR and CR were evaluated with T2DM rats induced by a high-fat diet (HFD) along with a low dose of streptozocin (STZ). Ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) was performed to discover potential biomarkers. The levels of pro-inflammatory cytokines; biochemical indexes in serum, and the activities of key enzymes related to glycometabolism in liver were assessed by ELISA kits. qPCR was applied to examine mRNA levels of key targets in MAPK and insulin signaling pathways. Protein expressions of p65; p-p65; phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K); phosphorylated-PI3K (p-PI3K); protein kinase B (Akt); phosphorylated Akt (p-Akt) and glucose transporter 2 (Glut2) in liver were investigated by Western blot analysis. Results Remarkably, hyperglycaemia, dyslipidemia, inflammation, and insulin resistance in T2DM were ameliorated after oral administration of SR and CR, particularly their combined extracts. The effects of SR, CR, low dose of combined extracts (LSC) and high dose of combined extracts (HSC) on pro-inflammatory cytokine transcription in T2DM rats showed that the MAPK pathway might account for the phenomenon with down-regulation of MAPK (P38 mitogen-activated protein kinases (P38), extracellular regulated protein kinases (ERK), and c-Jun N-terminal kinase (JNK)) mRNA, and protein reduction in p-P65. While mRNA levels of key targets such as insulin receptor substrate 1 (IRS1), PI3K, Akt2, and Glut2 in the insulin signaling pathway were notably up-modulated, phosphorylations of PI3K, Akt, and expression of Glut2 were markedly enhanced. Moreover, the increased activities of phosphoenolpyruvate carboxykinase (PEPCK), fructose-1,6-bisphosphatase (FBPase), glucose 6-phosphatase (G6Pase), and glycogen phosphorylase (GP) were highly reduced and the decreased activities of glucokinase (GK), phosphofructokinase (PFK), pyruvate kinase (PK), and glycogen synthase (GS) in liver were notably increased after treatment. Further investigation indicated that the metabolic profiles of plasma and urine were clearly improved in T2DM rats. Fourteen potential biomarkers (nine in plasma and five in urine) were identified. After intervention, these biomarkers returned to normal level to some extent. Conclusion The results showed that SR, CR, and combined extract groups were normalized. The effects of combined extracts were more remarkable than single herb treatment. Additionally, this study also showed that the metabonomics method is a promising tool to unravel how traditional Chinese medicines work.

Wogonin, a flavonoid isolated from Scutellaria baicalensis, has anti-viral activities against influenza infection via modulation of AMPK pathways

Wogonin, a flavonoid isolated from Scutellaria baicalensis, has attracted increasing scientific attention in recent years because of its potent anti-tumor activity. Its role during viral infection has largely been unexplored. Wogonin treatment effectively suppressed both influenza A and B virus replication in Madin-Darby Canine Kidney (MDCK) cells and human lung epithelial (A549) cells. In contrast, wogonin treatment following influenza A virus infection led to up-regulation of interferon (IFN)-induced antiviral signaling. Additionally, influenza A virus infection in A549 cells induced 5' adenosine monophosphate-activated protein kinase (AMPK) phosphorylation and activation in a time-dependent manner and wogonin treatment led to the suppression of AMPK phosphorylation. Furthermore, the treatment with AMPK-specific inhibitor (compound C; CC) attenuated influenza A virus replication. These data suggest that wogonin possesses a potent anti-influenza activity mediated by regulation of AMPK activation, suggesting that wogonin has the potential to be developed as an anti-influenza drug.