Baicalin suppresses lung carcinoma and lung metastasis by SOD mimic and HIF-1alpha inhibition. Eur J Pharmacol. 2010;630:121-130. [PMID: 20036231 DOI: 10.1016/j.ejphar.2009.12.014]

Synthesis and biological evaluation of panaxadiol ester derivatives possessing pyrazole and pyrrole moiety as HIF-1α inibitors

Hypoxia-inducing factor-1α (HIF-1α) is overexpressed in variety of tumor patients and plays an important role in the regulation of hypoxia response in tumor cells. Therefore, its inhibitors have become one of the targets for the treatment of a variety of cancers. Two series of panaxadiol (PD) ester derivatives containing pyrazole (18a-j) and pyrrole (19a-n) moiety were synthesized and their HIF-1α inhibitory activities were evaluated. Among all the target compouds, compounds 18c, 19d, and 19n (IC50 = 8.70-10.44 μM) showed better HIF-1α inhibitory activity than PD (IC50 = 13.35 μM). None of these compounds showed cytotoxicity above 100 μM and inhibited HIF-1α transcription in a dose-dependent manner. These compounds showed good antitumor activity and provide lead compounds for further design and activity study of PD ester derivatives.

Baicalin promotes the sensitivity of NSCLC to cisplatin by regulating ferritinophagy and macrophage immunity through the KEAP1-NRF2/HO-1 pathway

BACKGROUND

Cisplatin (DDP) chemotherapy is commonly used in therapy for non-small cell lung cancer (NSCLC), but increased drug resistance has become a huge obstacle. Baicalin (BA) contributed to the sensitivity of NSCLC to DDP. Here, we aimed to further probe the pathophysiological mechanisms of BA in NSCLC.

METHODS

A549 and A549/DDP cells and xenograft mice were treated with BA and DDP. Xenograft mice were treated additionally with the NRF2 inducer (Bardoxolone methyl, BM) and KEAP1 knockdown. The levels of ferritinophagy-related proteins and biomarkers were determined. The autophagosomes were observed. M1 macrophage polarization and the contents of related indicators were analyzed. The involvement of KEAP1/NRF2/HO-1 was determined.

RESULTS

BA inhibited cell development, and the effect of BA and DDP on cell development was additive. The abundance of ferritinophagy-related proteins and the number of autophagosomes were induced by BA. BA also promoted the transition of GSH to GSSH. BA favored M1 macrophage polarization and affected the expression of related proteins. When BA and DDP combined, these molecular phenomena were further exacerbated. BA induced accumulation of KEAP1 and reduction of NRF2 and HO-1. However, BM and KEAP1 knockdown disrupted the synergistic effects of BA and DDP on inhibiting NSCLC growth. BM and KEAP1 knockdown reversed DDP and BA-promoted protein expression activity and M1 macrophage polarization.

CONCLUSION

Our findings suggest that BA is involved in ferritinophagy and macrophage immunity through the KEAP1-NRF2/HO-1 axis, thereby improving the DDP sensitivity in NSCLC, which could provide new candidates for treatment strategies.

Baicalin induces cell death of non-small cell lung cancer cells via MCOLN3-mediated lysosomal dysfunction and autophagy blockage

BACKGROUND

Non-small cell lung cancer (NSCLC) accounts for 85 % of lung cancer, becoming the most mortality of all cancers globally. Blockage of autophagy in NSCLC represents a promising therapeutic strategy that inhibits angiogenesis and overcomes drug resistance. Natural ingredients in anti-tumor adjuvants are increasingly reported to promote cell death with less side effects and the potential to increase chemotherapeutic drugs sensitivity. Baicalin, a Scutellaria baicalensis-extracted flavonoid glycoside, is reported to induce death of NSCLC cells, however, its effects on autophagy in NSCLC cells remain unclear.

PURPOSE

This study aimed to investigate the effect of baicalin on autophagic flux in NSCLC cells, unraveling the underlying mechanism including potential target and its role in cell death of NSCLC cells.

METHODS

In vitro anti-cancer effects of baicalin were verified by evaluating proliferation, clone formation, cell cycle, and cell migration in three NSCLC cell lines (A549, H1299, and PC-9). In vivo anti-tumor efficacies of baicalin were evaluated in subcutaneous xenograft tumor model in nude mice. Autophagy characterization in NSCLC cells included autophagic marker detection by western blot and immunofluorescence staining, subcellular structure observation by TEM, lysosomal function by RNA-seq and fluorescence staining (LysoTracker®, LysoSensor®, and acridine orange). Based on RNA-seq and molecular biological verification using apoptotic, autophagic, and lysosomal inhibitors, potential target molecule of baicalin was verified via Ca2+ flux assay, MCOLN3 knockdown by shRNA, and virtual molecular docking.

RESULTS

Baicalin inhibited NSCLC cell proliferation and migration, and suppressed tumor growth in vivo. Baicalin blocked the autophagic flux via activating the membranal cation channel MCOLN3 of lysosome, which disrupted its Ca2+ balance and induced lysosome dysfunction, leading to failure of autolysosome degradation. The cytoplasmic Ca2+ imbalance further resulted in depolarization of mitochondrial membrane potentials and ROS accumulation in NSCLC cells, mediating autophagy-related apoptosis.

CONCLUSION

This study demonstrated that baicalin inhibited autolysosome degradation by activating MCOLN3, leading to dysfunction in lysosomal pH elevation, thereby inhibiting autophagy in NSCLC, leading to apoptotic death of NSCLC cells. These findings enriched the existing theories of cancer therapy based on autophagy inhibition and underlying mechanisms of flavonoids as antitumor agents, paving the way for their clinical application in future.

Baicalin and lung diseases

Studies focusing on natural products have been conducted worldwide, and the results suggest that their natural ingredients effectively treat a wide range of illnesses. Baicalin (BIA) is a glycoside derived from the flavonoid baicalein present in Scutellaria baicalensis of the Lamiaceae family. Interestingly, BIA has been shown to protect the lungs in several animal models used in numerous studies. Therefore, we fully analyzed the data of the studies that focused on BIA's lung protective function against various injuries and included them in this review. Interestingly, BIA exhibits promising effects against acute lung injury, lung fibrosis, pulmonary embolism, and lung remodelling associated with COPD, LPS, and paraquat insecticide. BAI exhibits anticancer activity against lung cancer. Additionally, BIA potently attenuates lung damage associated with infections. BIA primarily exerts its therapeutic effects by suppressing inflammation, oxidative stress immune response, and apoptosis pathways. Nrf2/HO-1, PI3K/Akt, NF-κB, STAT3, MAPKs, TLR4, and NLRP3 are important targets in the pulmonary therapeutic effects of BIA on different lung disease models. Consequently, we recommend using it in future potential clinical applications, its contribution to treatment guidelines, and translating its promising effects to clinical practice in lung diseases.

Impact of nanocarrier aggregation on EPR-mediated tumor targeting

The aim of this study was to investigate the influence of excipients on retaining the particle size of methotrexate (MTX) loaded chitosan nanocarriers (CsNP) during lyophilization, which relates to the ability to enlarge the particle size and target specific areas. The nanocarriers were prepared using the ionic gelation technique with tripolyphosphate as a crosslinker. Three lyophilized formulations were used: nanosuspension without Lyoprotectant (NF), with mannitol (NFM), and with sucrose (NFS). The lyophilized powder intended for injection (PI) was examined to assess changes in particle size, product integrity, and comparative biodistribution studies to evaluate targeting ability. After lyophilization, NFS was excluded from in-vivo studies due to the product melt-back phenomenon. The particle size of the NF lyophile significantly increased from 176 nm to 261 nm. In contrast, NFM restricted the nanocarrier size to 194 nm and exhibited excellent cake properties. FTIR, XRD, and SEM analysis revealed the transformation of mannitol into a stable β, δ polymorphic form. Biodistribution studies showed that the nanocarriers significantly increased MTX accumulation in tumor tissue (NF = 2.04 ± 0.27; NFM = 2.73 ± 0.19) compared to the marketed PI (1.45 ± 0.25 μg), but this effect was highly dependent on the particle size. Incorporating mannitol yielded positive results in restricting particle size and favoring successful tumor targeting. This study demonstrates the potential of chitosan nanocarriers as promising candidates for targeted tumor drug delivery and cancer treatment.

Baicalin Blocks Colon Cancer Cell Cycle and Inhibits Cell Proliferation through miR-139-3p Upregulation by Targeting CDK16

Baicalin was reported to facilitate the apoptosis of colon cells and inhibit tumor growth in vivo. This study aimed to explore the specific mechanism and function of baicalin on colon cells. Relative mRNA levels were tested via qPCR. Cell proliferation, viability, and cell cycle phases were evaluated using MTT, colony formation, and flow cytometry assays, respectively. The interaction between miR-139-3p and cyclin-dependent kinase 16 (CDK16) was measured via a dual-luciferase reporter assay. Immunohistochemistry was used to count the positivity cells in tumor tissues collected from treated xenografted tumor mice. The results showed that baicalin increased miR-139-3p expression while also decreasing CDK16 levels, blocking the cell cycle, and inhibiting cell proliferation in colon cancer cells. miR-139-3p silencing or CDK16 overexpression abolished the inhibitory effects of baicalin on colon cancer proliferation. miR-139-3p directly targeted and interacted with CDK16 at the cellular level. The protective functions of miR-139-3p knockdown on tumor cells were abrogated by silencing CDK16. The combination of baicalin treatment and CDK16 knockdown further inhibited tumor growth of xenografted tumor mice compared with the groups injected with only sh-CDK16 or baicalin in vivo. In conclusion, baicalin inhibited colon cancer growth by modulating the miR-139-3p/CDK16 axis.

Pharmacological effects of baicalin in lung diseases

The flavonoids baicalin and baicalein were discovered in the root of Scutellaria baicalensis Georgi and are primarily used in traditional Chinese medicine, herbal supplements and healthcare. Recently, accumulated investigations have demonstrated the therapeutic benefits of baicalin in treating various lung diseases due to its antioxidant, anti-inflammatory, immunomodulatory, antiapoptotic, anticancer, and antiviral effects. In this review, the PubMed database and ClinicalTrials website were searched with the search string "baicalin" and "lung" for articles published between September 1970 and March 2023. We summarized the therapeutic role that baicalin plays in a variety of lung diseases, such as chronic obstructive pulmonary disease, asthma, pulmonary fibrosis, pulmonary hypertension, pulmonary infections, acute lung injury/acute respiratory distress syndrome, and lung cancer. We also discussed the underlying mechanisms of baicalin targeting in these lung diseases.

Crosstalk between xanthine oxidase (XO) inhibiting and cancer chemotherapeutic properties of comestible flavonoids- a comprehensive update

Gout is an inflammatory disease caused by metabolic disorder or genetic inheritance. People throughout the world are strongly dependent on ethnomedicine for the treatment of gout and some receive satisfactory curative treatment. The natural remedies as well as established drugs derived from natural sources or synthetically made exert their action by mechanisms that are closely associated with anticancer treatment mechanisms regarding inhibition of xanthine oxidase, feedback inhibition of de novo purine synthesis, depolymerization and disappearance of microtubule, inhibition of NF-ĸB activation, induction of TRAIL, promotion of apoptosis, and caspase activation and proteasome inhibition. Some anti-gout and anticancer novel compounds interact with same receptors for their action, e.g., colchicine and colchicine analogues. Dietary flavonoids, i.e., chrysin, kaempferol, quercetin, fisetin, pelargonidin, apigenin, luteolin, myricetin, isorhamnetin, phloretinetc etc. have comparable IC₅₀ values with established anti-gout drug and effective against both cancer and gout. Moreover, a noticeable number of newer anticancer compounds have already been isolated from plants that have been using by local traditional healers and herbal practitioners to treat gout. Therefore, the anti-gout plants might have greater potentiality to become selective candidates for screening of newer anticancer leads.

Quercetin attenuates sepsis-induced acute lung injury via suppressing oxidative stress-mediated ER stress through activation of SIRT1/AMPK pathways

Endoplasmic reticulum (ER) stress and mitochondrial dysfunction play a pivotal role in the pathological process of sepsis-induced acute lung injury (ALI). Quercetin has been proved to exert anti-inflammation in ALI. This study aimed to explore the protection mechanism of quercetin against sepsis-induced ALI via suppressing ER stress and mitochondrial dysfunction. Cecal ligation and puncture (CLP) mouse model was established to mimic sepsis, and LPS was used to stimulate murine lung epithelial (MLE-12) cells. We observed that quercetin ameliorated pulmonary pathological lesion and oxidative damage in sepsis-induced mice. In LPS-stimulated MLE-12 cells, quercetin could inhibit the level of ER stress as evidenced by decreased mRNA expression of PDI, CHOP, GRP78, ATF6, PERK, IRE1α and improve mitochondrial function, as presented by increased MMP, SOD level and reduced production of ROS, MDA. Meanwhile, transcriptome analysis revealed that quercetin upregulated SIRT1/AMPK mRNA expression. Furthermore, we used siRNA to knockdown SIRT1 in MLE-12 cells, and we found that SIRT1 knockdown could abrogate the quercetin-elicited antioxidation in vitro. Therefore, quercetin could protect against sepsis-induced ALI by suppressing oxidative stress-mediated ER stress and mitochondrial dysfunction via induction of the SIRT1/AMPK pathways.

Therapeutic potential of Scutellaria baicalensis Georgi in lung cancer therapy

BACKGROUND

Globally, lung cancer is the leading cause of cancer associated mortalities. The current conventional chemotherapy remains the preferred treatment option for lung cancer, as surgical resection plays little role in the treatment of over 75% of lung cancer patients. Therefore, there is a need to develop novel potential therapeutic drugs or adjuvants with a high efficiency and safety against lung cancer. Scutellaria baicalensis Georgi, a common Chinese medicinal herb that has been in use for more than 2000 years, has recently been shown to possess significant activities against lung cancer. However, current research progress on pharmacological effects and relevant molecular mechanisms of S. baicalensis in lung cancer therapy have not been systematically summarized.

PURPOSE

This review aimed at elucidating on the anti-lung cancer mechanisms and antitumor efficacies of S. baicalensis as well as its active ingredients, and providing a valuable reference for further investigation in this field.

METHODS

We used "Scutellaria baicalensis" or the name of the compound in S. baicalensis, in combination with "lung cancer" as key words to systematically search for relevant literature from the Web of Science and PubMed databases. Publications that investigated molecular mechanisms were the only ones selected for analysis. The PRISMA guidelines were followed.

RESULTS

Fifty-four publications met the inclusion criteria for this study. Five anti-lung cancer mechanisms of S. baicalensis and its constituent components are discussed. These mechanisms include apoptosis induction, cell-cycle arrest, suppression of proliferation, blockade of invasion and metastasis, and overcoming drug-resistance. These compounds exhibited high antitumor efficacies and safety against lung cancer xenografts.

CONCLUSION

Studies should aim at elucidating on the anti-cancer mechanisms of S. baicalensis to achieve the ultimate goal of lung cancer therapy.

An overview of pharmacological activities of baicalin and its aglycone baicalein: New insights into molecular mechanisms and signaling pathways

The flavonoids, baicalin, and its aglycone baicalein possess multi-fold therapeutic properties and are mainly found in the roots of Oroxylum indicum (L.) Kurz and Scutellaria baicalensis Georgi. These flavonoids have been reported to possess various pharmacological properties, including antibacterial, antiviral, anticancer, anticonvulsant, anti-oxidant, hepatoprotective, and neuroprotective effects. The pharmacological properties of baicalin and baicalein are due to their abilities to scavenge reactive oxygen species (ROS) and interaction with various signaling molecules associated with apoptosis, inflammation, autophagy, cell cycle, mitochondrial dynamics, and cytoprotection. In this review, we summarized the molecular mechanisms underlying the chemopreventive and chemotherapeutic applications of baicalin and baicalein in the treatment of cancer and inflammatory diseases. In addition, the preventive effects of baicalin and baicalein on mitochondrial dynamics and functions were highlighted with a particular emphasis on their anti-oxidative and cytoprotective properties. The current review highlights could be useful for future prospective studies to further improve the pharmacological applications of baicalein and baicalin. These studies should define the threshold for optimal drug exposure, dose optimization and focus on therapeutic drug monitoring, objective disease markers, and baicalin/baicalein drug levels.

Baicalin triggers apoptosis, inhibits migration, and enhances anti-tumor immunity in colorectal cancer via TLR4/NF-κB signaling pathway

Aberrant activation of the nuclear factor-kappa B (NF-κB) signaling pathway is closely implicated in colorectal cancer (CRC) growth, metastasis, and immune escape. In the present study, we reported natural derived compound of baicalin (BA), an efficient inhibitor of NF-κB, with good anti-tumor effect on CRC. CCK8 and colony formation assays showed that Baicalin significantly inhibit viability and proliferation in HCT-116 and CT26 cells. Additionally, Baicalin dramatically triggers mitochondria-mediated apoptosis in both HCT-116 and CT-26 cells, which is evidenced by loss of mitochondrial membrane potential and elevated cellular reactive oxygen species level. Treatment with Baicalin suppresses migration and invasion of CT26 cells by impairing TLR4/NF-κB signaling pathway. What's more, administration of Baicalin significantly retarded tumor growth rate in a subcutaneous xenograft tumor mouse model of CT26 cells. Treatment with Baicalin could ameliorate tumor immunosuppressive environment by downregulation of PD-L1 expression and proportion of myeloid-derived suppressor cells (MDSCs) and upregulation of percent of CD4⁺ and CD8⁺ T cells in CT26 tumors, thus improving anti-tumor immunity. In conclusion, our study demonstrated that baicalin triggers apoptosis, inhibits migration, and enhances anti-tumor immunity in colorectal cancer via TLR4/NF-κB signaling pathway, suggesting it might serve as a potential candidate drug for the treatment of CRC. PRACTICAL APPLICATIONS: In the present study, we reported natural derived compound of baicalin (BA), an efficient inhibitor of NF-κB, with good anti-tumor effect on CRC. We demonstrated that baicalin triggers mitochondria-mediated apoptosis, inhibits migration, and improves anti-tumor immunity in colorectal cancer via TLR4/NF-κB signaling pathway.

Baicalin attenuates XRCC1-mediated DNA repair to enhance the sensitivity of lung cancer cells to cisplatin

Baicalin plays important roles in different types of cancer. A previous report showed that baicalin attenuates cisplatin resistance in lung cancer. However, its mechanism remains unclear. In this study, we investigated the effect and mechanism of baicalin on DNA repair and sensitivity of lung cancer cells to cisplatin. A549 and A549/DPP cells were treated with baicalin and cisplatin. A549/DPP cells were transfected with XRCC1 and siXRCC1. Cell viability and DNA damage were detected by MTT and comet assay. Apoptosis rate and cell cycle were detected by flow cytometry assay. The expressions of Bax, Bcl-2, and Cyclin D1 were detected by western blot. XRCC1 expression was detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot. Baicalin and cisplatin decreased cell viability in A549 and A549/DPP cells in dose-dependent manner. Baicalin enhanced the effect of cisplatin on promoting apoptosis, arresting cell on S stage and triggering DNA damage accompanied with the upregulation of Bcl-2-associated X protein (Bax) and downregulation of B-cell lymphoma 2 (Bcl-2) and Cyclin D1 in A549/DPP cells. Moreover, baicalin promoted the inhibitory effect of cisplatin on XRCC1 expression in A549 and A549/DPP cells. However, the synthetic effects of baicalin and cisplatin on A549/DPP cells were partially inhibited by XRCC1 overexpression and promoted by XRCC1 knockdown. This study demonstrates that baicalin interferes with XRCC1-mediated cellar DNA repair to sensitize lung cancer cells to cisplatin.

Antimetastatic effects of VOflavonoid complexes on A549 cell line

BACKGROUND

Non-small-cell lung cancer (NSCLC) is the most frequent type of lung cancer and more than 90 % of mortality is due to metastasis-related deaths. Flavonoids are considered nutraceuticals due to the variety of pharmacological properties. In this paper, we studied the effects of baicalin, silibinin, apigenin, luteolin, and its oxidovanadium(IV) cation complexes on the viability, adhesion to fibronectin, invasion, and migration on human lung cancer cell line A549. In addition, in order to complete the study of the interaction of VOflavonoids and bovine serum albumin (BSA), the binding ability of silibinin and VOsil to the protein was evaluated.

METHOD

To establish the non-cytotoxic concentration range of the tested compounds, the cancer cell viability was evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. Cell migration and invasion assays were performed using Boyden chambers and adhesion assay using MTT method. The interaction of compounds with BSA were investigated in physiological buffer (pH = 7.4) by fluorescence spectroscopy.

RESULTS

All complexes inhibited the metastatic cascade steps to a greater extent than their respective ligands. Likewise, based on binding constant values (K_b) for BSA-silibinin and BSA-VOsil, we can suggest that both compounds can interact with the protein.

CONCLUSION

Although all the complexes suppressed cell adhesion, invasion and migration, VOlut can be considered as a good candidate to continue the trials because it presented encouraging results as a potential antitumor and antimetastatic agent, and can be transported by BSA.

Investigation on the biological activity of anthocyanins and polyphenols in blueberry

Blueberry (Vaccinium spp.) is a fruit recognized in the world as healthy, and many of its active ingredients have important physiological functions. This study analyzed the antioxidant activity, antitumor activity, and immune function of anthocyanins and polyphenols extracted from blueberries. The crude extracts of anthocyanins and polyphenols were obtained from blueberries and then purified, and the extract exhibited excellent dose-dependent antitumor activity and antioxidant activity in vivo and in vitro. The purified anthocyanins and polyphenol compounds showed higher antioxidant activity, whereas the crude extract had a better inhibitory effect on tumor proliferation than pure extract, and the blueberry anthocyanin and polyphenol crude product mixture showed a more powerful tumor suppressor, which may be the result of the synergistic effect of multiple compounds. The crude extracts were also more efficient at improving immune function, as reflected by measurements of change in body weight, thymus and spleen indices, macrophage phagocytosis, lymphocyte transformation capacity, superoxide dismutase activity, malondialdehyde content, and serum nitric oxide levels. These results indicate that blueberry anthocyanins and polyphenol extracts can improve immune function and reduce the metastasis and proliferation of cancer cells. This study reveals the functions of important active substances in blueberries and provides support for the development of functional health products and therapeutic drugs. PRACTICAL APPLICATION: We compared the biological activity of crude and purified anthocyanins and polyphenol extracts from blueberries and tested their effects on improving immune function. This study contributes to a better understanding of the bioactivity of blueberry extracts and is valuable for further applications of blueberries in medicine.

Baicalin mediated regulation of key signaling pathways in cancer

Baicalin has been widely investigated against different types of malignancies both at the cellular and molecular levels over the past few years. Due to its remarkable anti-proliferative potential in numerous cancer cell lines, it has created immense interest as a potential chemotherapeutic modality compared to other flavonoids. Thus, this review focuses on the recent accomplishments of baicalin and its limitations in cancer prevention and treatment. Further, combination studies and nanoformulations using baicalin to treat cancer along with the metabolism, bioavailability, toxicity, and pharmacokinetics have been discussed. The present review explains biological source, and anti-proliferative potential of baicalin against cancers including breast, colon, hepatic, leukemia, lung, and skin, as well as the relevant mechanism of action to modulate diverse signaling pathways including apoptosis, cell cycle, invasion, and migration, angiogenesis, and autophagy. The anticancer mechanism of baicalin in orthotropic and xenograft mice models have been deliberated. The combination studies of baicalin in novel therapies as chemotherapeutic adjuvants have also been summarized. The low bioavailability, fast metabolism, and poor solubility, and other significant factors that limit the clinical use of baicalin have been examined as a challenge. The improvement in the pharmacokinetics and pharmacodynamics of baicalin with newer approaches and the gaps are highlighted, which could establish baicalin as an effective and safe compound for cancer treatment as well as help to translate its potential from bench to bedside.

Potential Molecular Mechanisms of Plantain in the Treatment of Gout and Hyperuricemia Based on Network Pharmacology

BACKGROUND

The incidence of gout and hyperuricemia is increasing year by year in the world. Plantain is a traditional natural medicine commonly used in the treatment of gout and hyperuricemia, but the molecular mechanism of its active compounds is still unclear. Based on network pharmacology, this article predicts the targets and pathways of effective components of plantain for gout and hyperuricemia and provides effective reference for clinical medication.

METHOD

Traditional Chinese medicine systems pharmacology database and analysis platform (TCMSP) and SymMap databases were used to screen out the active compounds and their targets in plantain. GeneCards, Therapeutic Target Database (TTD), and Online Mendelian Inheritance in Man (OMIM) databases were used to find the targets corresponding to gout and hyperuricemia. Venn diagram was used to obtain the intersection targets of plantain and diseases. The interaction network of the plantain active compounds-targets-pathways-diseases was constructed by using Cytoscape 3.7.2 software. Finally, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were carried out.

RESULT

Seven active compounds were identified by network pharmacological analysis, including dinatin, baicalein, baicalin, sitosterol, 6-OH-luteolin, stigmasterol, and luteolin. Plantain plays a role in gout and hyperuricemia diseases by regulating various biological processes, cellular components, and molecular functions. The core targets of plantain for treating gout are MAPK1, RELA, TNF, NFKBIA, and IFNG, and the key pathways are pathways in cancer, hypoxia-inducible factor-1 (HIF-1) signaling pathway, interleukin (IL)-17 signaling pathway, Chagas disease (American trypanosomiasis), and relaxin signaling pathway. The core targets of plantain for hyperuricemia are RELA, MAPK1, NFKBIA, CASP3, CASP8, and TNF, and the main pathways are pathways in cancer, apoptosis, hepatitis B, IL-17 signaling pathway, and toxoplasmosis.

CONCLUSION

This study explored the related targets and mechanisms of plantain for the treatment of gout and hyperuricemia from the perspective of network pharmacological analysis, reflecting the characteristics of multiple components, multiple targets, and multiple pathways, and it provides a good theoretical basis for the clinical application of plantain.

Antioxidants in Cancer Therapy: Recent Trends in Application of Nanotechnology for Enhanced Delivery

Recently, the occurrence of cancer has significantly increased; it represents the second-most frequent cause of death after cardiovascular diseases. Many dietary antioxidants have shown large impact as effective agents for cancer prevention by reducing oxidative stress, which has been a part in the development of many diseases, including cancer. One of the obstacles in the delivery of antioxidant therapies into the required domain lies in the inadequate delivery of these agents to their intended site of action. Using nanotechnology in delivery of antioxidants leads to increased therapeutic index and higher drug concentration in tumor tissues, thus enhancing anticancer treatment. In this review, we discuss the role of different antioxidants in cancer therapy and their improved therapeutic effect through their formulation using nanotechnology.

Baicalein inhibits the growth of oral squamous cell carcinoma cells by downregulating the expression of transcription factor Sp1

Oral squamous cell carcinoma (OSCC), the most common malignancy of the oral cavity, accounts for >90% of all diagnosed oral cancer cases. Baicalein, a naturally derived compound, has been shown to alter p65 and the nuclear factor (NF)‑κB pathway, thus exerting cytotoxic effects on various tumor cell types. However, the mechanism of action of baicalein in OSCC has not been fully elucidated. In the present study, the proliferation of OSCC cells treated with baicalein was examined using a CCK‑8 assay. The effects of baicalein on the cell cycle and apoptosis of OSCC cells were determined by flow cytometric analyses. The expression of specificity protein 1 (Sp1), p65 and p50 at the mRNA and protein levels was determined by reverse transcription‑quantitative PCR and western blot analysis, respectively. The results of the present study demonstrated that baicalein suppresses the proliferation of OSCC cell lines in vivo and in vitro. Baicalein also induced apoptosis of OSCC cells and arrested the cell cycle at the G0/G1 phase. Baicalein inhibited the expression of Sp1, p65 and p50 by downregulating the relative mRNA levels. Baicalein reduced the activity of NF‑κB in OSCC cells. Knockdown of Sp1 also resulted in reduced expression of p65 and p50. In addition, Sp1 silencing enhanced the effects of baicalein. In conclusion, the present study demonstrated that baicalein suppresses the growth of OSCC cells through an Sp1/NF‑κB‑dependent mechanism.

Baicalin Regulates Proliferation, Apoptosis, Migration, and Invasion in Mesothelioma

Background

Baicalin, one of the main bioactive components extracted from the traditional Chinese medicine baical Skullcap root, has an anti-tumor activity which had been studied in several cancers. However, its role in human mesothelioma remains unknown. In this study, we investigated the anti-tumor mechanisms of baicalin in the mesothelioma cell line MESO924.

Material/Methods

Effects of baicalin on mesothelioma were assessed by measuring cell viability, apoptosis, migration, invasion, inactivation of signaling intermediates, and cell-cycle alterations.

Results

Baicalin inhibited the proliferation, migration, and invasion of human mesothelioma cells and increased their apoptosis, all in a dose-dependent manner. Specifically, baicalin decreased the expression of p-EGFR, p-AKT, p-MAPK, p-S6, Bcl-2, and VEGF and increased the expression of Bax in mesothelioma cells. The suppressed mesothelioma cellular proliferation is due to the arrest of the S cell cycle by baicalin. Inhibition of the PI3K/AKT/mTOR signaling pathway by a PI3K/AKT/mTOR inhibitor augmented the anti-proliferation effects induced by baicalin. In addition, baicalin increased the sensitivity of MESO924 to the chemotherapeutic drugs doxorubicin, cisplatin, and pemetrexed.

Conclusions

These results highlight the roles of baicalin in inhibiting cell growth, migration, and invasion of mesothelioma cells while increasing apoptosis and sensitizing cells to chemotherapeutic agents through the PI3K/AKT/mTOR signaling pathway, which indicates that baicalin could be a useful drug for mesothelioma therapy.

Baicalein inhibits growth of Epstein-Barr virus-positive nasopharyngeal carcinoma by repressing the activity of EBNA1 Q-promoter

Epstein-Barr virus (EBV) can establish a life-long latent infection in the host and is associated with various human malignancies, including nasopharyngeal carcinoma (NPC), the most common cancer originated from nasopharynx. EBV nuclear antigen 1 (EBNA1) is the only viral protein absolutely demanded for segregation, replication, transcription and maintenance of EBV viral genome in host cells. Baicalein, a bioactive flavonoid compound purified from the root of Scutellariae baicaleinsis, displays anti-inflammatory, immunosuppressive, and anti-tumor properties. In this study, the therapeutic effects and functional mechanism of baicalein on EBV-positive human NPC were determined. Cell Counting Kit-8 assays and cell formation colony were performed to investigate that baicalein can suppress proliferation of EBV-infected human NPC cells. Flow cytometric and hoechst 33258 staining results indicated that baicalein induced cell cycle arrest and apoptosis. Western blotting results demonstrated that baicalein down-regulates EBNA1 expression but not reduces the stability and half-life of EBNA1 in EBV-infected NPC cells. Additionally, the mRNA level of EBNA1 was examined by real time-PCR, the activity of EBNA1 Q promoter (Qp) was determined by dual luciferase reporter assay. Considering that transcription factor specificity protein 1 (Sp1) can maintain EBNA1 Qp active. Further analyses also elucidated that baicalein inhibits the expression of Sp1 while knock-down Sp1 by specific shRNAs decreases the expression and transcription levels of EBNA1. Therefore, the results suggested that baicalein may decrease EBNA1 expression level in EBV-positive NPC cells via inhibiting the activity of EBNA1 Q-promoter while over-expression of EBNA1 attenuate the inhibitory effect of baicalein. Finally, it was found that baicalein may strongly reduce growth of tumor in the mouse xenograft model of EBV-positive NPC. These results indicated that baicalein inhibits growth of EBV-positive NPC by repressing the activity of EBNA1 Q-promoter. Baicalein may be used as a therapeutic agent to treat EBV-positive NPC.

Baicalin Inhibits Human Cervical Cancer Cells by Suppressing Protein Kinase C/Signal Transducer and Activator of Transcription (PKC/STAT3) Signaling Pathway

BACKGROUND Like other human cancers, the malignancy of cervical cancer is also characterized by abilities of proliferation, migration, and invasion. Protein kinase C-zeta (PKCζ) has been highly correlated with several human cancers. Baicalin was proven to regulate PKC. This study aimed to investigate the anti-cancer effect and involved molecular mechanisms of baicalin on human cervical cancer. MATERIAL AND METHODS Baicalin at various concentrations was used to treat 2 human cervical cancer cell lines HeLa and SiHa. The proliferation was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenylterazolium bromide (MTT) assay. The apoptosis was detected by terminal transferase UTP nick end labeling (TUNEL) assay. Wound healing assay and Transwell assay were used to evaluate the migration and invasion respectively. Western blotting was performed to assess the protein expression levels. RESULTS Baicalin administration significantly reduced the viability by facilitating the apoptosis in HeLa and SiHa cells. Baicalin treatment also significantly reduced the wound closure and cell amount invaded as measured by Transwell assay. The expression levels of PKCζ, survivin, matrix metalloproteinase (MMP)2, MMP9 as well as the phosphorylation of signal transducer and activator of transcription (STAT) 3 were reduced in baicalin administrated cervical cancer cells. CONCLUSIONS Baicalin exerted anti-cancer effects on human cervical cancer cells by targeting STAT3 regulated signaling pathways.

Baicalin induces cellular senescence in human colon cancer cells via upregulation of DEPP and the activation of Ras/Raf/MEK/ERK signaling

Baicalin is a natural flavonoid glycoside which has potent anti-tumor and antioxidant activity in cancer cells. In the present study, we found that baicalin treatment significantly induced senescence in colon cancer cells. Furthermore, baicalin upregulated the expression of decidual protein induced by progesterone (DEPP) in HCT116 colon cancer cells, which accompanied with the activation of Ras/Raf/MEK/ERK and p16^INK4A/Rb signaling pathways. Meanwhile, these phenomena also appeared under the anti-oxidation effect exerted by baicalin. In addition, ectopic expression of DEPP in HCT116 cells significantly induced the activity of senescence-associated β-galactosidase (SA-β-Gal) in tumor cells regulated by Ras/Raf/MEK/ERK signaling pathway. Knockdown of DEPP by RNA interference efficiently counteracted the baicalin-mediated growth inhibition, senescence and cell cycle arrest in cancer cells. Importantly, in a xenograft mouse model of human colon cancer, we further confirmed that baicalin treatment dramatically inhibited tumor growth, which was due to the induction of tumor cellular senescence via the upregulation of DEPP and the activation of Ras/Raf/MEK/ERK signaling in vivo. In addition to baicalin treatment, we found that the hypoxia-response protein DEPP functions as a positive regulator involving the regulations of Ras/Raf/MEK/ERK signaling pathway and inhibition of human colon cancer by other anti-oxidative drugs, such as curcumin and sulforaphane, resulting in tumor cellular senescence. These results collectively suggest that baicalin upregulates the expression of DEPP and activates its downstream Ras/Raf/MEK/ERK and p16^INK4A/Rb pathways by acting as an antioxidant, leading to senescence in colon cancer cells.

Scutellaria baicalensis and Cancer Treatment: Recent Progress and Perspectives in Biomedical and Clinical Studies

Scutellaria baicalensis (Huangqin in Chinese) is a major traditional Chinese medicine (TCM) herb, which has a long history of use in the treatment of a variety of symptoms correlated with cancer. In the past decade, the potential of S. baicalensis and single compounds derived from it as anticancer agents targeting various pathways has received extensive research attention. Specifically, the proliferation and metastases inhibiting properties of the single compounds in cancer have been studied; however, the underlying mechanisms remain unclear. This review summarizes the various mechanisms, pathways and molecular targets involved in the anticancer activity of S. baicalensis and its single compounds. However, the aim of this review is to provide a more thorough view of the last 10 years to link traditional use with modern research and to highlight recently discovered molecular mechanisms. Extracts and major flavonoids derived from S. baicalensis have been found to possess anticancer effects in multiple cancer cell lines both in vitro and in vivo. Further investigation is warranted to better understand the underlying mechanisms and to discover novel targets and cancer therapeutic drugs that may improve both the survival and quality of life of cancer patients.

Proteomic Analysis and Functional Studies of Baicalin on Proteins Associated with Skin Cancer

Abundant evidence supports the key role of ultraviolet radiation (UVR) in skin cancer development. The human skin, especially the epidermal layer, is the main defense against UV radiation. Baicalin is a major bioactive component of Scutellaria baicalensis Georgi, a plant which has been found to exhibit antitumor activity. The anticarcinogenic mechanism of baicalin is not completely understood. We have reported that baicalin inhibited UVB-induced photo-damage and apoptosis in HaCaT cells (human skin keratinocytes). The aim of the present study is to investigate the cellular gene targets responsible for baicalin’s antitumor activity by performing two-dimensional electrophoresis liquid chromatography-mass spectrometry/mass spectrometry (2-DE LC-MS/MS) with HaCaT cells following UVB and baicalin exposure. Two-DE for protein separation was performed, followed by matrix-assisted laser desorption/ionization mass spectrometry and database searches. Nucleophosmin (NPM)-specific siRNA was designed and synthesized, and the small interfering RNA was transfected into skin squamous cancer A431 cells to knockdown the NPM expression. Proliferation and cell cycle status were assessed by CCK8 and flow cytometric analyses, respectively. We have identified 38 protein spots that are differentially expressed in HaCaT cells exposed to baicalin and/or UVB irradiation These proteins are involved in detoxification, proliferation, metabolism, cytoskeleton and motility. In particular, we found several proteins that have been linked to tumor progression and resistance, such as NPM. Baicalin treatment reduced the cellular proliferation rate and induced arrest during the S-phase of the cell cycle in A431 cells. NPM1 silencing significantly enhanced the effect of baicalin. Our data indicated that baicalin results in the significant inhibition of tumor growth in the A431 cell line, which may be associated with the regulation of the NPM gene expression.

Baicalin Protects against TNF-α-Induced Injury by Down-Regulating miR-191a That Targets the Tight Junction Protein ZO-1 in IEC-6 Cells

Tumor necrosis factor-alpha (TNF-α) plays an important role in the developing process of inflammatory bowel disease. Tight junction protein zonula occludens-1 (ZO-1), one of epithelial junctional proteins, maintains the permeability of intestinal barrier. The objective of this study was to investigate the mechanism of the protective effect of baicalin on TNF-α-induced injury and ZO-1 expression in intestinal epithelial cells (IECs). We found that baicalin pretreatment significantly improved cell viability and cell migration following TNF-α stimulation. miR-191a inhibitor increased the protective effect of baicalin on cell motility injured by TNF-α. In addition, miR-191a down-regulated the mRNA and protein level of its target gene ZO-1. TNF-α stimulation increased miR-191a expression, leading to the decline of ZO-1 mRNA and protein. Moreover, pretreatment with baicalin reversed TNF-α induced decrease of ZO-1 and increase of miR-191a, miR-191a inhibitor significantly enhanced ZO-1 protein expression restored by baicalin. These results indicate that baicalin exerts a protective effect on IEC-6 (rat small intestinal epithelial cells) cells against TNF-α-induced injury, which is at least partly via inhibiting the expression of miR-191a, thus increasing ZO-1 mRNA and protein levels.

Lung-targeting drug delivery system of baicalin-loaded nanoliposomes: development, biodistribution in rabbits, and pharmacodynamics in nude mice bearing orthotopic human lung cancer

The present study aims to develop a kind of novel nanoliposomes for the lung-targeting delivery system of baicalin as a Chinese medicine monomer. Baicalin-loaded nanoliposomes were prepared by the effervescent dispersion and lyophilized techniques. Baicalin-loaded nanoliposomes had an average particle size of 131.7±11.7 nm with 0.19±0.02 polydispersity index, 82.8%±1.24% entrapment efficiency and 90.47%±0.93% of yield and sustaining drug release effect over 24 h and were stable for 12 months at least. In vitro no hemolytic activity was observed for the experimental drug concentration. After intravenous administration of baicalin-loaded nanoliposomes to rabbits, drug concentration in the lungs was the highest among the tested organs at all time points and was significantly higher than that of its solution. For the targeting parameters, the relative intake rate and the ratio of peak concentration of lung were 4.837 and 2.789, respectively. Compared with plasma, liver, spleen, and kidney, the ratios of targeting efficacy (T_e)_liposomes to (T_e)_injection of lung were increased by a factor of 14.131, 1.893, 3.357, and 3.470, respectively. Furthermore, the results showed that the baicalin-loaded nanoliposomes did not induce lung injury. Importantly, baicalin-loaded nanoliposomes showed better antitumor therapeutic efficacy in the nude mice bearing orthotopic human lung cancer with the median survival time of blank liposomes (11.40±0.16 days), baicalin solution (17.30±0.47 days), and baicalin-loaded nanoliposomes (25.90±0.53 days). Therefore, the liposome is a promising drug carrier with an excellent lung-targeting property and therapeutic effect for the treatment of lung disease, such as lung cancer.

Baicalin Inhibits Renal Cell Apoptosis and Protects Against Acute Kidney Injury in Pediatric Sepsis

Background

Pediatric sepsis has high morbidity in children, may lead to acute kidney injury (AKI), and further aggravate the disease. Baicalin is a kind of flavonoid in Scutellaria baicalensis Georgi and has been reported to protect against several diseases, but its roles in septic AKI remain unclear. This study aimed to uncover the effects of baicalin in AKI during pediatric sepsis.

Material/Methods

Blood urea nitrogen (BUN) and serum creatinine (Cr) levels were detected in 50 pediatric patients, who underwent basic therapy with or without baicalin adjunctive therapy. Mouse sepsis models were constructed by cecal ligation and puncture (CLP) and treated with baicalin intragastrically, after which BUN and Cr examination, TUNEL apoptosis assay, and expression analyses of BAX and BCL2 were performed.

Results

Baicalin adjunctive therapy significantly decreased BUN and Cr levels in pediatric sepsis patients (P<0.05). CLP led to elevated BUN and Cr levels in the mouse model (P<0.01), indicating kidney injury accompanied by sepsis. Baicalin decreased BUN and Cr levels (P<0.05), and reduced the apoptotic cell percent in the renal tissue (P<0.05) of the CLP model. It inhibited BAX and promoted BCL2 in the renal tissue, which was consistent with cell apoptosis changes.

Conclusions

Baicalin is capable of suppressing renal cell apoptosis and protecting against AKI in pediatric sepsis. This study provides a potential adjunctive therapy for treating AKI in pediatric sepsis, and further research is necessary to reveal its deeper mechanisms.

Baicalin promoted site-2 protease and not site-1 protease in endoplasmic reticulum stress-induced apoptosis of human hepatocellular carcinoma cells

Baicalin (5,6-dihydroxy-7-o-glucuronide flavone) is an extract from the roots of Chinese herb Huang Qin (Scutellaria baicalensis Georgi) and is reported to have antioxidative, antiproliferative, anti-inflammatory, and anticancer activities. This study aimed to investigate the inhibitory effect of baicalin on human hepatocellular carcinoma (HCC) cells and the involvement of endoplasmic reticulum stress-induced cell apoptosis. Two human HCC cell lines, HepG2 and SMMC7221, were used in this study. The cells were incubated with baicalin solutions at various concentrations. A 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to assess cell proliferation inhibition; a TUNEL assay was used to evaluate cell apoptosis; small RNA interference was applied to silence IRE1, ATF6, and protein kinase R-like ER kinase (PERK), which are transmembrane proteins inducing cell apoptosis, and two proteases (S1P and S2P) which cleave ATF6. Real-time PCR was used to evaluate the silencing effects of specific siRNA. Expression levels of specific proteins were analyzed by western blotting. Baicalin was found to inhibit the proliferation of HCC cells by inducing apoptosis in a concentration-dependent manner. Elevated expression levels of GRP78, CHOP, p50-ATF6, and caspase12 were found after baicalin incubation. Compared with IRE1 and PERK silencing, ATF6 knockdown dramatically impaired baicalin's apoptosis-inducing activity. Furthermore, S2P silencing, rather than S1P silencing, was also found to impair baicalin-induced HCC cell apoptosis significantly. In conclusion, (a) baicalin inhibits human HCC cells by inducing apoptosis; (b) baicalin induces cell apoptosis by activating ATF6 signaling pathway in endoplasmic reticulum (ER) stress;

LC-UV Determination of Baicalin in Rabbit Plasma and Tissues for Application in Pharmacokinetics and Tissue Distribution Studies of Baicalin after Intravenous Administration of Liposomal and Injectable Formulations

A simple and sensitive LC-UV method to investigate the pharmacokinetics and biodistribution pattern of baicalin in rabbits was established and validated. Baicalin and the internal standard, rutin, were extracted from biosamples using acetonitrile as protein precipitation after pretreated with ammonium acetate buffer (pH 3.5; 1 M) to obtain a pure chromatographic peak and high extraction recovery. Chromatographic separation was achieved on a reverse-phase C18 column with a gradient elution at flow rate of 1.0 mL/min. UV absorption was set at 278 nm. Chromatographic response was linear over the ranges of 0.05–10.00 μg/mL in plasma and 0.05–300.00 μg/g in tissues with the limits of quantification of 50.0 ng/mL in plasma and tissues, and the limit of detection of baicalin in bio-samples of 15 ng/mL. The RSD of intra-and inter-day for the biosamples were from 4.19% to 10.84% and from 4.37% to 10.93%, respectively. The accuracy of plasma and tissue samples ranged from 81.6% to 95.2% and 80.8% to 98.4%, respectively. The extraction recoveries ranged from 81.5% to 88.3% for plasma, from 73.1% to 93.2% for tissues, respectively. Baicalin was stable in rabbit biosamples. The validated method was successfully applied to the study of the pharmacokinetics and tissue distribution of baicalin after intravenous administration of liposomal and injectable formulations to rabbits. Compared to baicalin injection, the pharmacokinetics and biodistribution behavior of baicalin was altered significantly in rabbits treated with its liposomes and drug concentration in the lungs was greatly increased.

The Traditional Chinese Medicine Baicalein Potently Inhibits Gastric Cancer Cells

Baicalein, a traditional Chinese medicine, is a member of the flavone subclass of flavonoids. It has been reported to have anticancer activities in several human cancer cell lines in vitro. However, the therapeutic effects of baicalein on human gastric cancer and the mechanisms of action of baicalein have not been extensively studied. In the present study, we utilized a cell viability assay and an in vivo tumor growth assay to test the inhibitory effects of baicalein on gastric cancer. Analyses of the cell cycle, apoptosis and alterations in protein levels were performed to elucidate how baicalein functions in gastric cancer. We found that baicalein could potently inhibit gastric cancer cell growth and colony formation. Baicalein robustly induced arrest at the S phase in the gastric cancer cell line SGC-7901. It induced SGC-7901 cell apoptosis and disrupted the mitochondrial membrane potential (ΔΨm) in a dose-dependent manner. Analysis of protein expression levels in SGC-7901 cells showed downregulation of Bcl-2 and upregulation of Bax in response to baicalein treatment. These results indicate that baicalein induces apoptosis of gastric cancer cells through the mitochondrial pathway. In an in vivo subcutaneous xenograft model, baicalein exhibited excellent tumor inhibitory effects. These results indicate that baicalein may be a potential drug for gastric cancer therapy.

Therapeutic effect of baicalin on experimental autoimmune encephalomyelitis is mediated by SOCS3 regulatory pathway

Natural compounds derived from medicinal plants have long been considered a rich source of novel therapeutic agents. Baicalin (Ba) is a bioactive flavonoid compound derived from the root of Scutellaria baicalensis, an herb widely used in traditional medicine for the treatment of various inflammatory diseases. In this study, we investigate the effects and mechanism of action of Ba in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Ba treatment effectively ameliorated clinical disease severity in myelin oligodendrocyte glycoprotein (MOG)35–55 peptide-induced EAE, and reduced inflammation and demyelination of the central nervous system (CNS). Ba reduced infiltration of immune cells into the CNS, inhibited expression of proinflammatory molecules and chemokines, and prevented Th1 and Th17 cell differentiation via STAT/NFκB signaling pathways. Further, we showed that SOCS3 induction is essential to the effects of Ba, given that the inhibitory effect of Ba on pathogenic Th17 responses was largely abolished when SOCS3 signaling was knocked down. Taken together, our findings demonstrate that Ba has significant potential as a novel anti-inflammatory agent for therapy of autoimmune diseases such as MS.

Recent trends in preclinical drug-drug interaction studies of flavonoids--Review of case studies, issues and perspectives

Because of health benefits that are manifested across various disease areas, the consumption of herbal products and/or health supplements containing different kinds of flavonoids has been on the rise. While the drug-drug interaction potential between flavonoids and co-ingested drugs still remain an issue, opportunities exist for the combination of flavonoids with suitable anti-cancer drugs to enhance the bioavailability of anti-cancer drugs and thereby reduce the dose size of the anti-cancer drugs and improve its therapeutic index. In recent years, scores of flavonoids have undergone preclinical investigation with variety of drugs encompassing therapeutic areas such as oncology (etoposide, doxorubicin, paclitaxel, tamoxifen etc.), immunosuppression (cyclosporine) and hypertension (losartan, felodipine, nitrendipine etc.). The review provides examples of the recent trends in the preclinical investigation of 14 flavonoids (morin, quercetin, silibinin, kaempferol etc.) with various co-administered drugs. The relevance of combination of flavonoids with anti-cancer drugs and a framework to help design the in vitro and in vivo preclinical studies to gain better mechanistic insights are discussed. Also, concise discussions on the various physiological factors that contribute for the reduced bioavailability of flavonoids along with the significant challenges in the data interpretation are provided.

The Effect of Baicalin as A PPAR Activator on Erythroid Differentiation of CD133(+)Hematopoietic Stem Cells in Umbilical Cord Blood

OBJECTIVE

The peroxisome proliferator-activated receptors (PPARs) are a group of nu- clear receptor proteins whose functions as transcription factors regulate gene expres- sions. PPARs play essential roles in the regulation of cellular differentiation, development, and metabolism (carbohydrate, lipid, protein), and tumorigenesis of higher organisms. This study attempts to determine the effect of baicalin, a PPARγ activator, on erythroid differentiation of cluster of differentiation 133(+)(CD133(+)) cord blood hematopoietic stem cells (HSCs).

MATERIALS AND METHODS

In this experimental study, in order to investigate the effects of the PPARγ agonists baicalin and troglitazone on erythropoiesis, we isolated CD133(+) cells from human umbilical cord blood using the MACS method. Isolated cells were cultured in erythroid-inducing medium with or without various amounts of the two PPARγ activa- tors (baicalin and troglitazone). Erythroid differentiation of CD133(+)cord blood HSCs were assessed using microscopic morphology analysis, flow cytometric analysis of erythroid surface markers transferrin receptor (TfR) and glycophorin A (GPA) and bycolony forming assay.

RESULTS

Microscopic and flow cytometric analysis revealed the erythroid differentiation of CD133(+)cord blood HSCs under applied erythroid inducing conditions. Our flow cytometric data showed that the TfR and GPA positive cell population diminished significantly in the presence of either troglitazone or baicalin. The suppression of erythroid differentiation in response to PPARγ agonists was dose-dependent. Erythroid colony-forming ability of HSC decreased significantly after treatment with both PPARγ agonists but troglitazone had a markedly greater effect.

CONCLUSION

Our results have demonstrated that PPARγ agonists modulate erythroid dif- ferentiation of CD133(+)HSCs, and therefore play an important role in regulation of normal erythropoiesis under physiologic conditions. Thus, considering the availability and applica- tion of this herbal remedy for treatment of a wide range of diseases, the inhibitory effect of baicalin on erythropoiesis should be noted.

Korean Scutellaria baicalensis Georgi methanol extracts inhibits metastasis via the Forkhead Box M1 activity in hepatocellular carcinoma cells

ETHNOPHARMACOLOGICAL RELEVANCE

Scutellaria baicalensis Georgi, commonly known as skullcaps, and it has been widely used as traditional therapeutic herb in several eastern Asia including Korea, China and Japan because of its remarkable anti-inflammatory and anti-cancer effects. Our study focuses on the anti-metastatic effects of Scutellaria baicalensis Georgi in hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Methanol extract of Scutellaria baicalensis Georgi was examined for identification of its composition by HPLC-MS/MS. The extract was evaluated for the anti-metastasis activity using HepG2 hepatocellular carcinoma cells via immunoblotting and RT-PCR. For mechanical study, specific Forkhead Box M1 (FOXM1) vector was transfected to HepG2 cells.

RESULTS

Scutellaria baicalensis Georgi potentially inhibited proliferation of HepG2 cells dose dependently. Scutellaria baicalensis Georgi decreased metastasis through the regulation of matrix metalloproteinase 2 (MMP-2) and FOXM1 activities at the transcription and translation levels.

CONCLUSIONS

The results of the present study suggest that Scutellaria baicalensis Georgi could be a potent chemotherapeutic agent against HCC. Its clinical use guarantee for further study and individual flavonoids from Scutellaria baicalensis Georgi should also be investigated.

Combined use of phospholipid complexes and self-emulsifying microemulsions for improving the oral absorption of a BCS class IV compound, baicalin

The aim of this study was to develop a formulation to improve the oral absorption of baicalin (BA) by combining a phospholipid complex (PC) and self-emulsifying microemulsion drug delivery system (SMEDDS), termed BA–PC–SMEDDS. BA–PC was prepared by a solvent evaporation method and evaluated by complexation percentage (CP). The physicochemical properties of BA–PC were determined. The synergistic effect of PC and SMEDDS on permeation of BA was studied in vitro with Caco-2 cells and in situ with a single pass intestinal perfusion model. The improved bioavailability of BA in BA–PC–SMEDDS was confirmed in an in vivo rat model. The CP of BA–PC reached 100% when the molar ratio of drug to phospholipid (PP) was ≥1:1. The solubility of BA–PC increased in both water and octanol, and the log P_o/w of BA–PC was increased significantly. BA–PC–SMEDDS could be dispersed more evenly in water, compared to BA and BA–PC. Both the Caco-2 cell uptake and single-pass intestinal perfusion models illustrated that transport of BA in BA–PC was lower than that of free BA, while improved significantly in BA–PC–SMEDDS. The relative bioavailability of BA–PC(1:2)–SMEDDS was 220.37%. The combination system of PC and SMEDDS had a synergistic effect on improving the oral absorption of BA.

Baicalin attenuates transforming growth factor-β1-induced human pulmonary artery smooth muscle cell proliferation and phenotypic switch by inhibiting hypoxia inducible factor-1α and aryl hydrocarbon receptor expression

Objectives

Baicalin, a natural flavone, has antithrombotic, antihyperlipidemic and antiinflammortory activity. It can also inhibit cancer cell proliferation and reduce brain cell apoptosis. This study aimed to elucidate the effect of baicalin on the excessive proliferation of human pulmonary arterial smooth muscle cells (HPASMCs) induced by transforming growth factor-β1 (TGF-β1) and to investigate the roles of hypoxia inducible factor-1α (HIF-1α) and aryl hydrocarbon receptor (AhR) in mediating this TGF-β1-induced excessive proliferation of HPASMCs.

Methods

TGF-β1-induced proliferation of HPASMCs was assayed using the CCK8 method. The cellular phenotype was identified by immunocytochemical staining. Expression of HIF-1α and AhR mRNA was determined by real-time quantitative PCR.

Key findings

TGF-β1 promoted significantly HPASMC proliferation (P &lt; 0.05) and induced a phenotypic switch from the contractile to synthetic type. Baicalin inhibited this TGF-β1-induced phenotypic switch and consequently the excessive growth of HPASMCs in a time-dependent and dose-dependent manner (P &lt; 0.05). Furthermore, baicalin attenuated the abnormal proliferation of HPASMCs through suppression of the HIF-1α and AhR pathways.

Conclusions

Our study shows that baicalin has the potential to be used as a novel drug in the treatment of pulmonary arterial hypertension pathology by antagonizing HIF-1α and AhR expression and subsequently decreasing HPASMC proliferation and the phenotypic switch.

Flavonoid components in Scutellaria baicalensis inhibit nicotine-induced proliferation, metastasis and lung cancer-associated inflammation in vitro

The objective of the present study was to investigate the therapeutic efficacy of flavonoid components in Scutellaria baicalensis on proliferation, metastasis and lung cancer-associated inflammation during nicotine induction in the A549 and H1299 lung cancer cell lines. After experimental period, augmentation of proliferation was observed, accompanied by marked decrease in apoptotic cells in nicotine-induced lung cancer cells; additionally, nicotine-exposed cells exhibited increased invasive and migratory abilities based on invasion and wound-healing assay. Flavones in Scutellaria, baicalin, baicalein and wogonin significantly counteracted the above deleterious changes. Moreover, assessment of tumor apoptotic and metastatic factors on mRNA levels by quantitative PCR and protein levels by western blotting revealed that these phytochemical treatments effectively negated nicotine-induced upregulated expression of bcl-2, bcl-2/bax ratio, caspase-3, matrix metalloproteinase (MMP)-2 and MMP-9 as well as downregulated expression of bax. Further analysis of inflammatory markers such as tumor necrosis factor (TNF)-α and interleukin (IL)-6 in cell culture supernatant and mRNA and protein expression of nuclear transcription factor-kappaB (NF-κB) and I kappa B-alpha (IκB-α) was carried out to substantiate the anti-inflammatory effect of flavones in Scutellaria in nicotine-exposed lung cancer cells. The therapeutic effects observed in the present study are attributed to the potent potential against proliferation, metastasis and inflammatory microenvironment by flavonoid components in Scutellaria in nicotine-induced lung cancer cells.

Kinetics and mechanism study of competitive inhibition of jack-bean urease by baicalin

Baicalin (BA) is the principal component of Radix Scutellariae responsible for its pharmacological activity. In this study, kinetics and mechanism of inhibition by BA against jack-bean urease were investigated for its therapeutic potential. It was revealed that the IC₅₀ of BA against jack-bean urease was 2.74 ± 0.51 mM, which was proved to be a competitive and concentration-dependent inhibition with slow-binding progress curves. The rapid formation of initial BA-urease complex with an inhibition constant of K_i = 3.89 × 10⁻³ mM was followed by a slow isomerization into the final complex with an overall inhibition constant of K_i* = 1.47 × 10⁻⁴ mM. High effectiveness of thiol protectors against BA inhibition indicated that the strategic role of the active-site sulfhydryl group of the urease was involved in the blocking process. Moreover, the inhibition of BA was proved to be reversible due to the fact that urease could be reactivated by dithiothreitol but not reactant dilution. Molecular docking assay suggested that BA made contacts with the important activating sulfhydryl group Cys-592 residues and restricted the mobility of the active-site flap. Taken together, it could be deduced that BA was a competitive inhibitor targeting thiol groups of urease in a slow-binding manner both reversibly and concentration-dependently, serving as a promising urease inhibitor for treatments on urease-related diseases.

Baicalein inhibits the invasion and metastatic capabilities of hepatocellular carcinoma cells via down-regulation of the ERK pathway

Baicalein, a widely used Chinese herbal medicine, has historically been used in anti-inflammatory and anti-cancer therapies. However, the anti-metastatic effect and molecular mechanism(s) of baicalein on hepatocellular carcinoma (HCC) remain poorly understood. Therefore, the purpose of this study was to assess the anti-metastatic effects of baicalein and related mechanism(s) on HCC. Based on assays utilized in both HCC cell lines and in an animal model, we found that baicalein inhibited tumor cell metastasis in vivo and in vitro. Furthermore, after treatment with baicalein for 24 hours, there was a decrease in the levels of matrix metalloproteinase-2 (MMP-2), MMP-9 and urokinase-type plasminogen activator (u-PA) expression as well as proteinase activity in hepatocellular carcinoma MHCC97H cells. Meanwhile, the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2 were increased in a dose-dependent fashion. Moreover, baicalein treatment dramatically decreased the levels of the phosphorylated forms of MEK1 and ERK1/2. MEK1 overexpression partially blocked the anti-metastatic effects of baicalein. Combined treatment with an ERK inhibitor (U0126) and baicalein resulted in a synergistic reduction in MMP-2, MMP-9 and u-PA expression and an increase in TIMP-1 and TIMP-2 expression; the invasive capabilities of MHCC97H cells were also inhibited. In conclusion, baicalein inhibits tumor cell invasion and metastasis by reducing cell motility and migration via the suppression of the ERK pathway, suggesting that baicalein is a potential therapeutic agent for HCC.

Tanshinone IIA and Baicalin inhibiting the formation of benzo[a]pyrene and benzo[a]pyrene induced cytotoxicity: correlation with scavenging free radical

Benzo[a]pyrene (BaP), a ubiquitous environmental pollutant, is formed by incomplete combustion of organic materials, and causes oxidative damage to cells and tissues due to reactive oxygen species (ROS). The purpose of this study is to investigate the inhibition of Tanshinone IIA and Baicalin on the formation of BaP as well as the cytotoxicity in human umbilical vein endothelial cells (HUVECs) induced by BaP. The results showed that BaP formations in mainstream smoke were inhibited by 21μg/cigarette of Tanshinone IIA with a 12.8% decrease, and by 60μg/cigarette of Baicalin with an 11.1% decrease, respectively. Tanshinone IIA could protect HUVECs from the damage caused by BaP in a dose-dependent manner from 7.5 to 30μg/ml. 6μg/ml Baicalin significantly increased the cell survival rate from 47.37% to 84.21% compared with BaP-treated cells. Both Tanshinone IIA and Baicalin markedly attenuated the increase of LDH release, enhanced the activity of SOD and GPx and inhibited the generation of MDA in BaP-damaged HUVECs in vitro. In vivo exploration showed that the two compounds were capable of enhancing the activity of SOD and inhibiting generation of MDA in mainstream smoke-damaged in mice. Superoxide anion radical and hydroxyl radical were obviously inhibited by Tanshinone IIA and Baicalin. These data demonstrate an inhibition of Tanshinone IIA and Baicalin on the formation of BaP and the cytotoxicity on HUVECs related to free Radical induced by BaP.

Baicalin induces apoptosis in leukemia HL-60/ADR cells via possible down-regulation of the PI3K/Akt signaling pathway

BACKGROUND

The effect and possible mechanism of traditional Chinese medicine, baicalin, on the PI3K/ Akt signaling pathway in drug-resistant human myeloid leukemia HL-60/ADR cells have been investigated in this current study.

METHODS

HL-60/ADR cells were treated by 20, 40, 80 μmol/L baicalin followed by cell cycle analysis at 24h. The mRNA expression level of the apoptosis related gene, Bcl-2 and bad, were measured by RT-PCR on cells treated with 80 μmol/L baicalin at 12, 24 and 48hr. Western blot was performed to detect the changes in the expression of the proteins related to HL-60/ADR cell apoptosis and the signaling pathway before and after baicalin treatment, including Bcl-2, PARP, Bad, Caspase 3, Akt, p-Akt, NF-κB, p-NF-κB, mTOR and p-mTOR.

RESULTS

Sub-G1 peak of HL-60/ADR cells appeared 24 h after 20 μmol/L baicalin treatment, and the ratio increased as baicalin concentration increased. Cell cycle analysis showed 44.9% G0/G1 phase cells 24 h after baicalin treatment compared to 39.6% in the control group. Cells treated with 80 μmol/L baicalin displayed a trend in decreasing of Bcl-2 mRNA expression over time. Expression level of the Bcl-2 and PARP proteins decreased significantly while that of the PARP, Caspase-3, and Bad proteins gradually increased. No significant difference in Akt expression was observed between treated and the control groups. However, the expression levels of p-Akt, NF-κB, p-NF-κB, mTOR and p-mTOR decreased significantly in a time-dependent manner.

CONCLUSIONS

We conclude that baicalin may induce HL-60/ADR cell apoptosis through the PI3K/AKT signaling pathway.

Preferential inhibition of hepatocellular carcinoma by the flavonoid Baicalein through blocking MEK-ERK signaling

Baicalein is a purified flavonoid extracted from the roots of Scutellaria baicalensis or Scutellaria radix. Although previous studies have suggested that Baicalein possesses an in vitro anti-hepatocellular carcinoma activity, its in vivo effects and mechanisms of action are still not completely understood. In this study, Baicalein at concentrations of 40-120 µM exhibited significant cytotoxicity to three hepatocellular carcinoma (HCC) cell lines but marginal cytotoxicity to a normal liver cell line in vitro. Compared to a standard chemotherapy drug, 5-fluorouracil (5-FU), Baicalein had greater effect on HCC cells but less toxicity on normal liver cells. Treatment with Baicalein dramatically reduced mitochondrial transmembrane potential, and activated caspase-9 and caspase-3. Blockade of Baicalein-induced apoptosis with a pan-caspase inhibitor partially attenuated Baicalein-induced growth inhibition in HCC. Baicalein treatment significantly inhibited tumor growth of HCC xenografts in mice. Induction of apoptosis was demonstrated in Baicalein-treated xenograft tumors by the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Furthermore, Baicalein treatment dramatically decreased the levels of phosphorylation of MEK1, ERK1/2 and Bad in vitro and in vivo. Overexpression of human MEK1 partially blocked Baicalein-induced growth inhibition. Consequently, these findings suggest that Baicalein preferentially inhibits HCC tumor growth through inhibition of MEK-ERK signaling and by inducing intrinsic apoptosis.