Baicalein potently suppresses angiogenesis induced by vascular endothelial growth factor through the p53/Rb signaling pathway leading to G1/S cell cycle arrest

Integrating network pharmacology, experimental validation and molecular docking to reveal the alleviation of Yinhuang granule on idiopathic pulmonary fibrosis

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a chronic disease characterized by the abnormal proliferation of fibroblast and excessive deposition of extracellular matrix (ECM), accompanied by inflammation and ultimately respiratory failure. Yinhuang granule (YHG), with clinical properties of clearing heat, detoxifying and anti-inflammation, is commonly used to heal upper respiratory diseases in China for decades.

PURPOSE

To explore the improvement of YHG on bleomycin (BLM)-induced IPF in mice and its possible engaged mechanism.

METHODS

The mortality rate was recorded, lung function was determined and hematoxylin-eosin (H&E) staining was carried out to explore the alleviation of YHG on BLM-caused IPF in mice. Hydroxyproline, collagen I and collagen III contents were detected, and Sirius red and Masson staining were conducted to evaluate YHG's alleviation on lung fibrosis. The underlying mechanism was predicted by network pharmacology, and confirmed by Real-time polymerase chain reaction (RT-PCR), Western-blot (WB) and enzyme linked immunosorbent assay (ELISA). The binding affinity between related key proteins and active compounds in YHG was calculated by using molecular docking, and further validated by cellular thermal shift assay (CESTA).

RESULTS

YHG (400, 800 mg/kg) weakened lung damage and pulmonary fibrosis in mice induced by BLM. Network pharmacology and experimental validation displayed that inflammation and angiogenesis participated in the YHG-provided improvement on IPF, and key involved molecules included tumor necrosis factor-α (TNFα), vascular endothelial growth factor-A (VEGFA), interleukine-6 (IL-6), etc. The data of molecular docking presented that some main active compounds from YHG had a high binding affinity with TNFR1 or VEGFR2, and some of them were further validated by CESTA.

CONCLUSION

YHG effectively improved the BLM-induced IPF in mice via reducing inflammation and angiogenesis.

Flavonoids with Anti-Angiogenesis Function in Cancer

The formation of new blood vessels, known as angiogenesis, significantly impacts the development of multiple types of cancer. Consequently, researchers have focused on targeting this process to prevent and treat numerous disorders. However, most existing anti-angiogenic treatments rely on synthetic compounds and humanized monoclonal antibodies, often expensive or toxic, restricting patient access to these therapies. Hence, the pursuit of discovering new, affordable, less toxic, and efficient anti-angiogenic compounds is imperative. Numerous studies propose that natural plant-derived products exhibit these sought-after characteristics. The objective of this review is to delve into the anti-angiogenic properties exhibited by naturally derived flavonoids from plants, along with their underlying molecular mechanisms of action. Additionally, we summarize the structure, classification, and the relationship between flavonoids with their signaling pathways in plants as anti-angiogenic agents, including main HIF-1α/VEGF/VEGFR2/PI3K/AKT, Wnt/β-catenin, JNK1/STAT3, and MAPK/AP-1 pathways. Nonetheless, further research and innovative approaches are required to enhance their bioavailability for clinical application.

Baicalin and baicalein in modulating tumor microenvironment for cancer treatment: A comprehensive review with future perspectives

Cancer is a leading cause of death worldwide. The burden of cancer incidence and mortality is increasing rapidly. New approaches to cancer prevention and treatment are urgently needed. Natural products are reliable and powerful sources for anticancer drug discovery. Baicalin and baicalein, two major flavones isolated from Scutellaria baicalensis Georgi, a multi-purpose traditional medicinal plant in China, exhibit anticancer activities against multiple cancers. Of note, these phytochemicals exhibit extremely low toxicity to normal cells. Besides their cytotoxic and cytostatic activities toward diverse tumor cells, recent studies demonstrated that baicalin and baicalein modulate a variety of tumor stromal cells and extracellular matrix (ECM) in the tumor microenvironment (TME), which is essential for tumorigenesis, cancer progression and metastasis. In this review, we summarize the therapeutic potential and the mechanism of action of baicalin and baicalein in the regulation of tumor microenvironmental immune cells, endothelial cells, fibroblasts, and ECM that reshape the TME and cancer signaling, leading to inhibition of tumor angiogenesis, progression, and metastasis. In addition, we discuss the biotransformation pathways of baicalin and baicalein, related therapeutic challenges and the future research directions to improve their bioavailability and clinical anticancer applications. Recent advances of baicalin and baicalein warrant their continued study as important natural ways for cancer interception and therapy.

Baicalein as Promising Anticancer Agent: A Comprehensive Analysis on Molecular Mechanisms and Therapeutic Perspectives

Despite significant therapeutic advancements for cancer, an atrocious global burden (for example, health and economic) and radio- and chemo-resistance limit their effectiveness and result in unfavorable health consequences. Natural compounds are generally considered safer than synthetic drugs, and their use in cancer treatment alone, or in combination with conventional therapies, is increasingly becoming accepted. Interesting outcomes from pre-clinical trials using Baicalein in combination with conventional medicines have been reported, and some of them have also undergone clinical trials in later stages. As a result, we investigated the prospects of Baicalein, a naturally occurring substance extracted from the stems of Scutellaria baicalensis Georgi and Oroxylum indicum Kurz, which targets a wide range of molecular changes that are involved in cancer development. In other words, this review is primarily driven by the findings from studies of Baicalein therapy in several cancer cell populations based on promising pre-clinical research. The modifications of numerous signal transduction mechanisms and transcriptional agents have been highlighted as the major players for Baicalein’s anti-malignant properties at the micro level. These include AKT serine/threonine protein kinase B (AKT) as well as PI3K/Akt/mTOR, matrix metalloproteinases-2 & 9 (MMP-2 & 9), Wnt/-catenin, Poly(ADP-ribose) polymerase (PARP), Mitogen-activated protein kinase (MAPK), NF-κB, Caspase-3/8/9, Smad4, Notch 1/Hes, Signal transducer and activator of transcription 3 (STAT3), Nuclear factor erythroid 2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein-1 (Keap 1), Adenosine monophosphate-activated protein kinase (AMPK), Src/Id1, ROS signaling, miR 183/ezrin, and Sonic hedgehog (Shh) signaling cascades. The promise of Baicalein as an anti-inflammatory to anti-apoptotic/anti-angiogenic/anti-metastatic medicinal element for treating various malignancies and its capability to inhibit malignant stem cells, evidence of synergistic effects, and design of nanomedicine-based drugs are altogether well supported by the data presented in this review study.

Endogenous estrogens-breast cancer and chemoprevention

Breast cancer is the most common female malignancy and the second leading cause of cancer related deaths. It is estimated that about 40% of all cancer in women is hormonally mediated. Both estrogens and androgens play critical roles in the initiation and development of breast cancer. Estrogens influence normal physiological growth, proliferation, and differentiation of breast tissues, as well as the development and progression of breast malignancy. Breast cancer is caused by numerous endo- and exogenous risk factors. The paper presents estrogen metabolism, in particular 17β-estradiol and related hormones. The mechanisms of estrogen carcinogenesis include the participation of estrogen receptors, the genotoxic effect of the estrogen metabolites, and epigenetic processes that are also presented. The role of reactive oxygen species in breast cancer has been described. It called attention to a role of numerous signaling pathways in neoplastic transformation. Chemoprotective agents, besides other phytoestrogens, classical antioxidants, synthetic compounds, and their mechanisms of action have been shown.

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.

Molecular Targets of Genistein and Its Related Flavonoids to Exert Anticancer Effects

Increased health awareness among the public has highlighted the health benefits of dietary supplements including flavonoids. As flavonoids target several critical factors to exert a variety of biological effects, studies to identify their target-specific effects have been conducted. Herein, we discuss the basic structures of flavonoids and their anticancer activities in relation to the specific biological targets acted upon by these flavonoids. Flavonoids target several signaling pathways involved in apoptosis, cell cycle arrest, mitogen-activated protein kinase (MAPK), phosphoinositide 3-kinase (PI3K)/AKT kinase, and metastasis. Polo-like kinase 1 (PLK1) has been recognized as a valuable target in cancer treatment due to the prognostic implication of PLK1 in cancer patients and its clinical relevance between the overexpression of PLK1 and the reduced survival rates of several carcinoma patients. Recent studies suggest that several flavonoids, including genistein directly inhibit PLK1 inhibitory activity. Later, we focus on the anticancer effects of genistein through inhibition of PLK1.

Ginsenoside Rb1 promotes the growth of mink hair follicle via PI3K/AKT/GSK-3β signaling pathway

AIMS

Hair follicles play a critical role in the process of hair growth. The dermal papilla cells (DPCs) are an important component in the hair follicle regeneration and growth. This study investigated the effects of ginsenoside Rb1 on the growth of cultured mink hair follicles and DPCs.

MAIN METHODS

The mink hair follicles were treated with ginsenoside Rb1 for 9 days and their lengths were measured every three days. Real-time PCR was used to determine the mRNA expression of vascularization endothelial growth factor A (VEGF-A), VEGF receptor 2 (VEGF-R2) and TGF-β1. In addition, the levels of proteins were detected by western blot. Cell proliferation was determined by immunofluorescence staining of proliferation marker Ki-67 and cell cycle analysis was performed on flow cytometry. Moreover, cell migration was evaluated by wound healing assay.

KEY FINDINGS

Ginsenoside Rb1 promoted the growth of hair follicles, and proliferation and migration of DPCs. Ginsenoside Rb1 improved the expression levels of VEGFA and VEGF-R2, while attenuated the TGF-β1 expression both in hair follicles and DPCs. Furthermore, ginsenoside Rb1 facilitated the activation of PI3K/AKT/GSK-3β signaling pathway in hair follicles and DPCs.

SIGNIFICANCE

The results reveals a crucial role of PI3K/AKT/GSK-3β signaling pathway in ginsenoside Rb1-induced growth of hair follicles and DPCs.

Traditional Chinese medicine as a cancer treatment: Modern perspectives of ancient but advanced science

Traditional Chinese medicine (TCM) has been practiced for thousands of years and at the present time is widely accepted as an alternative treatment for cancer. In this review, we sought to summarize the molecular and cellular mechanisms underlying the chemopreventive and therapeutic activity of TCM, especially that of the Chinese herbal medicine-derived phytochemicals curcumin, resveratrol, and berberine. Numerous genes have been reported to be involved when using TCM treatments and so we have selectively highlighted the role of a number of oncogene and tumor suppressor genes in TCM therapy. In addition, the impact of TCM treatment on DNA methylation, histone modification, and the regulation of noncoding RNAs is discussed. Furthermore, we have highlighted studies of TCM therapy that modulate the tumor microenvironment and eliminate cancer stem cells. The information compiled in this review will serve as a solid foundation to formulate hypotheses for future studies on TCM-based cancer therapy.

Anti-angiogenic and anticancer effects of baicalein derivatives based on transgenic zebrafish model

Angiogenesis leads to tumor neovascularization by promoting tumor growth and metastatic spread, therefore, angiogenesis is considered as an attractive target for potential small molecule anticancer drug discovery. Herein, we report the structural modification and biological evaluation of baicalein derivatives, among which compound 42 had potent in vivo anti-angiogenic activity and wide security treatment window in transgenic zebrafish model. Further, 42 exhibited the most potent inhibitory activity on HUVEC proliferation, migration and tube formation in vitro. Moreover, 42 significantly inhibited growth of human lung cancer A549 cells and weak influence on human normal fibroblast L929 cells. The present research demonstrated that the significant anti-angiogenic and anticancer effects, which provided the supportive evidence for 42 could be used as a potential compound of cancer therapy.

Inhibitory effect of baicalein combined with gemcitabine in human pancreatic cancer cell lines

Pancreatic cancer is an aggressive disease with a particularly poor prognosis contributing to a substantial percentage of cancer-associated mortality rates. In the present study, the combination treatment of baicalein (BAI) and gemcitabine (GEM) was investigated to examine whether it inhibited the growth of the human CFPAC-1 pancreatic cancer cell line in vitro and in vivo. The cytotoxic interactions between BAI and GEM in human pancreatic cancer cell lines were determined using MTT assays, and the effect of the two agents on apoptosis was detected using Hoechst 33258 staining and annexin V/7-AAD. The protein levels of Bcl-2-associated X protein (Bax), B-cell lymphoma 2 (Bcl-2), caspase-3, poly ADP ribose polymerase (PARP) and survivin were detected using western blot analysis. Furthermore, the expression levels of Bax, Bcl-2, caspase-3 and survivin in tumor tissues were detected using immunohistochemistry. The results demonstrated that following GEM treatment, the growth of CFPAC-1 cells and xenografts in nude mice were inhibited, and the expression levels of Bcl-2 and survivin were downregulated, whilst the expression levels of Bax, caspase-3 and PARP were upregulated. These effects were enhanced with the use of BAI in combination with GEM. The mechanism underlying the anti-tumor effect of BAI combined with GEM may be associated with the induction of cell apoptosis and the inhibition of proliferation. To the best of our knowledge, this is the first evidence of the efficacy of BAI against pancreatic cancer and may provide the potential clinical evidence for the use of this drug combination for the treatment of patients with pancreatic cancer.

Baicalein reduces angiogenesis in the inflammatory microenvironment via inhibiting the expression of AP-1

Increasing clinical and experimental studies have demonstrated that refractory chronic inflammation will result in malignant tumor and anti-angiogenic therapy may be an effective way to thwart the progression. Baicalein, one of the major active flavanoids found in Scutellaria baicalensis Georgi, has been exhibited potent anti-inflammation and anti-tumor effects by reducing angiogenesis. However, the exact mechanism of baicalein on endothelial cells in inflammatory microenvironment was not clear yet. Here, we investigated the anti-angiogenic effect of baicalein by incubating human umbilical vein endothelial cells (HUVECs) with THP-1 conditioned medium in vitro. The tube formation of HUVECs and microvessel outgrowth of rat aorta were attenuated, as well as the number of newly formed blood vessels in chicken chorioallantoic membrane (CAM) was reduced by baicalein. This anti-angiogenic effect was mainly on account of the inhibited motility, migration and invasion of HUVECs. In addition, mechanistic studies showed that baicalein could bind to AP-1 directly and the expression of c-Jun and c-Fos in HUVECs was reduced, accompanied by their increased proteasomal degradation. Besides, baicalein suppressed the nuclear translation, heterodimer formation and DNA binding affinity of c-Jun and c-Fos. What's more, the anti-angiogenic effect of baicalein was further confirmed by matrigel plug assay in vivo. Taken together, our study demonstrated that baicalein could exert its anti-angiogenic effect in the inflammation microenvironment via inhibiting the transcriptional activity of AP-1, which suggested that baicalein might be an alternative treatment against refractory chronic inflammation.

Baicalein induces cervical cancer apoptosis through the NF-κB signaling pathway

To investigate the mechanism of baicalein in inducing human cervical cancer cell line C33A apoptosis. Baicalein (200 µM) was used to treat C33A cells. Cell proliferation was tested by the MTT assay. Cell apoptosis was detected by the TUNEL assay and caspase‑3 activity measurement. Cell cycle was determined by flow cytometry and associated gene expression at mRNA and protein levels. Nuclear factor (NF)‑κB activity was assessed by luciferase assay and western blotting. Baicalein suppressed cervical cancer cell C33A proliferation and induced cell apoptosis by activating caspase‑3 activity. Baicalein blocked cell cycle in G0/G1 phase through regulating the expression of associated genes. Baicalein inhibited NF‑κB activity by repressing nuclear translocation. Baicalein suppressed C33A proliferation and promoted cellular apoptosis by inhibiting NF‑κB signaling pathway. In conclusion, the results indicate that baicalein can inhibit cervical cancer cell proliferation and promote cell apoptosis by affecting NF-κB activity.

Baicalein inhibits tumor progression by inhibiting tumor cell growth and tumor angiogenesis

Baicalein, a herbal medicine, is a natural flavonoid isolated from the roots of Scutellaria baicalensis Georgi. It is known for its anticancer, anti-inflammatory and neuroprotective properties. Despite these well-known properties, it is not yet clear what effect baicalein has on tumor progression. Therefore, in the present study, we used B16F10 cells, Lewis lung carcinoma (LLC) cells, and human umbilical vein endothelial cells (HUVECs) to investigate the effect of baicalein on cell proliferation and viability, migration and tube formation in vitro. In addition, an experimental animal model was used to observe the growth rate and metastasis of tumors and tumor vessel formation in vivo. Our results showed that baicalein decreased the proliferation and migration and induced tumor cell death via caspase-3 activation in the B16F10 and LLC cells, and strongly inhibited tube formation and cell migration in HUVECs. Furthermore, mouse models showed that baicalein reduced the tumor volume and greatly reduced the tumor growth rate in the early stages of tumor progression, and the baicalein-treated groups had significantly reduced expression of CD31 (endothelial cell marker) and α-SMA (mural cell marker) in the tumors, indicating that baicalein inhibits tumor angiogenesis by disrupting tumor vasculature development. Comparison of the lymph node and lung samples collected from the baicalein-treated group, and the untreated group showed that baicalein reduced metastasis of the tumor to these tissues. In summary, baicalein reduced tumor progression and metastasis, directly induced tumor cell death, and inhibited tumor angiogenesis. Our results strongly demonstrate that baicalein is a potential chemotherapeutic agent.

Hydroethanolic Extract of Strychnos pseudoquina Accelerates Skin Wound Healing by Modulating the Oxidative Status and Microstructural Reorganization of Scar Tissue in Experimental Type I Diabetes

The effect of topical application of ointment based on Strychnos pseudoquina hydroethanolic extract in the cutaneous wounds healing in diabetic rats was evaluated. Samples of S. pseudoquina were submitted to phytochemical prospection and in vitro antioxidant assay. Thirty Wistar rats were divided into 5 groups: Sal-wounds treated with 0.9% saline solution; VH-wounds treated with 0.6 g of lanolin cream (vehicle); SS-wounds treated with silver sulfadiazine cream (10 mg/g); ES5- and ES10-wounds treated with an ointment of S. pseudoquina extract, 5% and 10%, respectively. Fragments of wounds were removed for histological and biochemical analysis every 7 days during 21 days. ES showed equivalent levels per gram of extract of total phenols and flavonoids equal to 122.04 mg for TAE and 0.60 mg for RE. The chlorogenic acid was one of the major constituents. S. pseudoquina extract presented high antioxidant potential in vitro. ES5 and ES10 showed higher wound healing rate and higher amount of cells, blood vessels, and type III and I collagen. The oxidative stress markers were lower in the ES5 and ES10 groups, while the antioxidants enzymes levels were higher. Ointment based on S. pseudoquina extract promotes a fast and efficient cutaneous repair in diabetic rats.

Anticancer properties of baicalein: a review

The constituents of many traditional Chinese herbal remedies are currently at the forefront of modern cancer research. Baicalein, a bioactive flavone widely used in nutraceuticals and pharmaceuticals, has shown great potential in the treatment and prevention of cancer without causing severe side effects. Baicalein induces cancer cell apoptosis and cause cell cycle arrest. It shows inhibitory effects on angiogenesis, metastasis and inflammation, all of which are necessary for the promotion and progression of cancer. This review presents an overview of the anti-cancer effects and mechanisms of baicalein. In addition, the bioavailability of baicalein and approaches to improve it are summarized. Treatments of baicalein in combination with other anti-cancer agents are also mentioned.

2'-Hydroxyflavanone ameliorates mesenteric angiogenesis and portal-systemic collaterals in rats with liver fibrosis

BACKGROUND AND AIM

Portal-systemic collaterals lead to dreadful consequences in patients with cirrhosis. Angiogenesis participates in the development of liver fibrosis, hyperdynamic circulation, and portal-systemic collaterals. 2'-Hydroxyflavanone (2'-HF), one of the citrus fruits flavonoids, is known to have antiangiogenesis effect without adverse response. However, the relevant effects in liver fibrosis have not been surveyed.

METHODS

Male Wistar rats received thioacetamide (TAA, 100 mg/kg tiw, i.p.) for 6 weeks to induce liver fibrosis. On the 29th to 42nd day, rats randomly received 2'-HF (100 mg/kg, qod, i.p.) or vehicle (corn oil). On the 43rd day, after hemodynamic measurements, the followings were surveyed: (i) severity of collaterals; (ii) mesenteric angiogenesis; (iii) mesenteric proangiogenic factors protein expressions; (iv) Mesenteric vascular endothelial cells apoptosis; and (v) Mesenteric expressions of proteins regulating apoptosis.

RESULTS

Compared with the vehicle group, 2'-HF did not significantly change body weight, mean arterial pressure, heart rate, and portal pressure in TAA rats. 2'-HF significantly alleviated the severity of collaterals, but the mesenteric phospho-ERK, ERK, phospho-Akt, Akt, COX1, COX2, VEGF, and VEGFR-2 protein expressions were not altered. The apoptotic index of 2'-HF group was significantly higher and the mesenteric protein expressions of pro-apoptotic factors, NFkB 50, NFkB 65, Bax, phospho-p53, 17 kD cleaved caspase 3, and 17 kD casepase 3 were up-regulated.

CONCLUSIONS

2'-HF does not influence the hemodynamics but alleviated the severity of collaterals in rats with liver fibrosis and early portal hypertension. This is, at least partly, attributed to enhanced apoptosis of mesenteric vascular endothelial cells.

Baicalein suppresses metastasis of breast cancer cells by inhibiting EMT via downregulation of SATB1 and Wnt/β-catenin pathway

BACKGROUND

The flavonoid baicalein, a historically used Chinese herbal medicine, shows a wide range of biological and pharmaceutical effects, among which its potent antitumor activity has raised great interest in recent years. However, the molecular mechanism involved in the antimetastatic effect of baicalein remains poorly understood. This study aimed to verify the inhibitory effects of baicalein on metastasis of MDA-MB-231 human breast cancer cells both in vitro and in vivo, as well as to investigate the related mechanisms.

METHODS

MTT assay was used to examine the inhibition of baicalein on proliferation of MDA-MB-231 cells. Wound healing assay and the in vitro invasion assay was carried out to investigate the effects of baicalein on migration and invasion of MDA-MB-231 cells, respectively. In order to explore the effects of baicalein on tumor metastasis in vivo, xenograft nude mouse model of MDA-MB-231 cells was established. Animals were randomly divided into four groups (control, therapy group, and low-dose and high-dose prevention group, n=6), and treated with baicalein as designed. Following sacrifice, their lungs and livers were collected to examine the presence of metastases. qRT-PCR and Western blot were performed to study the effects of baicalein on expression of SATB1, EMT-related molecules, and Wnt/β-catenin signaling components of MDA-MB-231 cells as well as the metastatic tissue. Effects of baicalein on the expression of target proteins in vivo were also analyzed by immunohistochemistry.

RESULTS

Our results indicated that baicalein suppressed proliferation, migration, and invasion of MDA-MB-231 cells in a time- and dose-dependent manner. Based on assays carried out in xenograft nude mouse model, we found that baicalein inhibited tumor metastasis in vivo. Furthermore, baicalein significantly decreased the expression of SATB1 in MDA-MB-231 cells. It suppressed the expression of vimentin and SNAIL while enhancing the expression of E-cadherin. Baicalein also downregulated the expression of Wnt1 and β-catenin proteins and transcription level of Wnt/β-catenin-targeted genes.

CONCLUSION

Our results demonstrate that baicalein has the potential to suppress breast cancer metastasis, possibly by inhibition of EMT, which may be attributed to downregulation of both SATB1 and the Wnt/β-catenin pathway. Taken together, baicalein may serve as a promising drug for metastasis treatment of breast cancer.

Baicalein antagonizes acute megakaryoblastic leukemia in vitro and in vivo by inducing cell cycle arrest

BACKGROUND

The prognosis of acute megakaryoblastic leukemia (AMKL) is really dismal, which urges for development of novel treatment. Baicalein is one type of flavonoids extracted from Scutellaria baicalensis Georgi (Huang Qin). It inhibited cell proliferation and subcutaneous tumor formation of many tumor cell lines. However, whether baicalein possesses anti-AMKL activities has not been tested.

RESULTS

We found that baicalein potently inhibited proliferation of multiple AMKL cells including CMK, CMY, Y10, 6133, and 6133 MPL/W515L due to apoptosis and cell cycle arrest at G1 phase. Unexpectedly, caspase inhibitor z-VAD-fmk did not restore cell proliferation. In contrast, ectopic expression of Cyclin D1 efficiently antagonized the inhibitory effect of baicalein. In addition, baicalein induced differentiation of 6133 MPL/W515L cells. Finally, baicalein promoted mice survival and reduced disease burden in a mouse model of AMKL.

CONCLUSIONS

Baicalein possesses potent anti-AMKL activity in vitro and in vivo. Baicalein may be a potent reagent for AMKL therapy.

The 786-0 renal cancer cell-derived exosomes promote angiogenesis by downregulating the expression of hepatocyte cell adhesion molecule

The aims of the current study were to determine whether 786‑0 renal cancer cell‑derived exosomes promote human umbilical vein endothelial cells (HUVECs) to form tubular structures and to uncover the underlying mechanisms associated with this process. Exosomes were extracted and purified using ultrafiltration and sucrose gradient centrifugation and characterized by transmission electron microscopy. Tubular structure formation was observed using the matrigel tubular assay. In addition, an adenovirus vector was used to transfect the hepatocyte cell adhesion molecule (hepaCAM) gene into renal cancer 786‑0 cells. The expression of hepaCAM and vascular endothelial growth factor (VEGF) mRNA and protein was determined by reverse transcription‑polymerase chain reaction and western blot analysis, respectively. Tumor cell‑derived exosomes were observed to significantly increase tubular formation in HUVECs. Following transfection with the hepaCAM gene, VEGF expression in 786‑0 cells was markedly decreased. In HUVECs, exosome treatment increased VEGF mRNA and protein expression, while hepaCAM expression was only decreased at the protein level. In the present study, renal cancer 786‑0 cell‑derived exosomes significantly promoted angiogenesis via upregulation of VEGF expression in HUVECs, which may be induced by the downregulation of hepaCAM.

Inhibitory effect of baicalin and baicalein on ovarian cancer cells

Ovarian cancer is one of the primary causes of death for women all through the Western world. Baicalin and baicalein are naturally occurring flavonoids that are found in the roots and leaves of some Chinese medicinal plants and are thought to have antioxidant activity and possible anti-angiogenic, anti-cancer, anxiolytic, anti-inflammatory and neuroprotective activities. Two kinds of ovarian cancer (OVCAR-3 and CP-70) cell lines and a normal ovarian cell line (IOSE-364) were selected to be investigated in the inhibitory effect of baicalin and baicalein on cancer cells. Largely, baicalin and baicalein inhibited ovarian cancer cell viability in both ovarian cancer cell lines with LD₅₀ values in the range of 45–55 μM for baicalin and 25–40 μM for baicalein. On the other hand, both compounds had fewer inhibitory effects on normal ovarian cells viability with LD₅₀ values of 177 μM for baicalin and 68 μM for baicalein. Baicalin decreased expression of VEGF (20 μM), cMyc (80 μM), and NFkB (20 μM); baicalein decreased expression of VEGF (10 μM), HIF-1α (20 μM), cMyc (20 μM), and NFkB (40 μM). Therefore baicalein is more effective in inhibiting cancer cell viability and expression of VEGF, HIF-1α, cMyc, and NFκB in both ovarian cancer cell lines. It seems that baicalein inhibited cancer cell viability through the inhibition of cancer promoting genes expression including VEGF, HIF-1α, cMyc, and NFκB. Overall, this study showed that baicalein and baicalin significantly inhibited the viability of ovarian cancer cells, while generally exerting less of an effect on normal cells. They have potential for chemoprevention and treatment of ovarian cancers.

Phytochemicals in ocular health: Therapeutic potential and delivery challenges

Diabetic retinopathy (DR) and age-related macular degeneration (AMD) are the leading causes of blindness in adults. The impact of these conditions on the quality of life is increasing in significance with a rise in life expectancy. The role of hyperglycemia, oxidative stress and inflammatory responses in the development and/or progression of DR and AMD, and several other sight threatening ocular diseases, is well established. In proliferative retinopathy, signals sent by the retina for nourishment, triggers the growth of fragile and abnormal blood vessels. Changes in ocular pressure may lead to rupture of these blood vessels causing severe vision problems. Recent in vitro and preclinical studies demonstrate that certain phytochemicals possessing potent antioxidant and anti-inflammatory activity and ocular blood flow enhancing properties may be very useful in the treatment of, or as a prophylactic measure for, DR and AMD. Apart from these properties they have also been investigated for their anti-bacterial, hormonal, enzyme stimulation, and anti-angiogenic activities. The attractive aspect of these potential therapeutic candidates is that they can act on multiple pathways identified in the etiology of DR, AMD, cataract and other ocular diseases. However, results from clinical trials have been somewhat ambiguous, raising questions about the concentrations of these bioflavonoids achieved in the neural retina following oral administration. Unfortunately, as of date, an efficient noninvasive means to deliver therapeutic agents/candidates to the back-of-the eye is still not available. This review examines some of these promising natural agents and discusses the challenges encountered in delivering them to the posterior segment ocular tissues through the oral route.

The effects of baicalein on canine osteosarcoma cell proliferation and death

Flavonoids are a group of modified triphenolic compounds from plants with medicinal properties. Baicalein, a specific flavone primarily isolated from plant roots (Scutellaria baicalensis), is commonly used in Eastern medicine for its anti-inflammatory and antineoplastic properties. Previous research shows greater efficacy for baicalein than most flavonoids; however, there has been little work examining their effects on sarcoma cells, let alone canine cells. Three canine osteosarcoma cell lines (HMPOS, D17 and OS 2.4) were treated with baicalein to examine cell viability, cell cycle kinetics, anchorage-independent growth and apoptosis. Results showed that osteosarcoma cells were sensitive to baicalein at concentrations from approximately 1 to 25 μM. Modest cell cycle changes were observed in one cell line. Baicalein was effective in inducing apoptosis and did not prevent doxorubicin cell proliferation inhibition in all the cell lines. The mechanism for induction of apoptosis has not been fully elucidated; however, changes in mitochondrial permeability supersede the apoptotic response.

Preparation and evaluation of self-microemulsifying drug delivery system of baicalein

The main object of this work is to prepare self-microemulsifying drug delivery system (SMEDDS) for oral bioavailability enhancement of a poorly water-soluble drug, baicalein. SMEDDS is the mixture of surfactants, cosurfactants, and oils, which are emulsified in aqueous media under conditions of gentle agitation or gastrointestinal motility. Solubility of baicalein was determined in various vehicles. Pseudo-ternary phase diagrams were constructed to identify the efficient self-emulsification region and droplet size distributions of the resultant microemulsions were determined using a particle size analyzer. Optimized SMEDDS formulations for baicalein were Cremophor RH40 (53.57%) as surfactant, Transcutol P (21.43%) as cosurfactant, and Caprylic capric triglyceride (ODO, 25%) as oil. The drug release rate of SMEDDS was significantly higher than that of the baicalein suspension. Comparison of the pharmacokinetics between baicalein-loaded SMEDDS and baicalein suspension was also performed in rats. The plasma concentrations of baicalein and baicalin, its mainly conjugated metabolite, were determined by HPLC method. The in vivo results showed that the absorption of baicalein from SMEDDS resulted in about 200.7% increase in relative bioavailability compared with that of the baicalein suspension. Our studies illustrated the potential use of SMEDDS for the delivery of hydrophobic compounds, such as baicalein by the oral route.

The detection of EBP50 expression using quantum dot immunohistochemistry in pancreatic cancer tissue and down-regulated EBP50 effect on PC-2 cells

Ezrin-radixin-moesin-binding phosphoprotein 50 (EBP50) is a putative tumor suppressor that is correlated with many human cancers. However, the function of EBP50 in pancreatic cancer (PC) has not been described. In this paper, the EBP50 expression level in PC tissues was characterized. In vitro, the effects of EBP50 down-regulation by siRNA in PC-2 and MiaPaCa-2 cells were evaluated. In addition, possible mechanisms that mediate the influence of EBP50 were examined. Our results show that the EBP50 expression pattern changes during transformation as there is a loss of the normal apical membrane distribution and an ectopic cytoplasmic over-expression of EBP50; furthermore, the EBP50 expression level is subsequently decreased during malignant progression. Down-regulation of EBP50 promoted cancer cell proliferation, increased the colony-forming ability of cells and accelerated the G1-to-S progression. Additionally, the loss of EBP50 accentuated β-catenin activity, increased cyclin E and phosphorylated Rb expression, and attenuated p27 expression compared to control cells. Our results suggest that EBP50 may function as a potential tumor suppressor.

Role of poly(ADP-ribose) glycohydrolase in the regulation of cell fate in response to benzo(a)pyrene

Poly(ADP-ribosyl)ation is a crucial regulator of cell fate in response to genotoxic stress. Poly(ADP-ribosyl)ation plays important roles in multiple cellular processes, including DNA repair, chromosomal stability, chromatin function, apoptosis, and transcriptional regulation. Poly(ADP-ribose) (PAR) degradation is carried out mainly by poly(ADP-ribose) glycohydrolase (PARG) enzymes. Benzo(a)pyrene (BaP) is a known human carcinogen. Previous studies in our laboratory demonstrated that exposure to BaP caused a concentration-dependent DNA damage in human bronchial epithelial (16HBE) cells. The role of PARG in the regulation of DNA damage induced by BaP is still unclear. To gain insight into the function of PARG and PAR in response to BaP, we used lentiviral gene silencing to generate 16HBE cell lines with stably suppressed PARG, and determined parameters of cell death and cell cycle following BaP exposure. We found that PARG was partially dependent on PAR synthesis, PARG depletion led to PAR accumulation. BaP-induced cell death was regulated by PARG, the absence of which was beneficial for undamaged cells. Our results further suggested that PARG probably has influence on ATM/p53 pathway and metabolic activation of BaP. Experimental evidences provided from this study suggest significant preventive properties of PAR accumulation in the toxicity caused by BaP.