Anti-Adipogenic Activity of Secondary Metabolites Isolated from Smilax sieboldii Miq. on 3T3-L1 Adipocytes.

Smilax sieboldii, a climbing tree belonging to Smilacaceae, has been used in traditional oriental medicine for treating arthritis, tumors, leprosy, psoriasis, and lumbago. To evaluate the anti-obesity effects of S. sieboldii (Smilacaceae), we screened methylene chloride (CH2Cl2), ethyl acetate (EtOAc), aqueous-saturated n-butanol, and ethanol (EtOH) extracts of the whole plant at various concentrations to inhibit adipogenesis in adipocytes. The 3T3-L1 cell line with Oil red O staining with the help of fluorometry was used as an indicator of anti-obesity activity. Bioactivity-guided fractionation of the EtOH extract and subsequent phytochemical investigation of the active CH2Cl2- and EtOAc-soluble fractions resulted in the isolation of 19 secondary metabolites (1-19), including a new α-hydroxy acid derivative (16) and two new lanostane-type triterpenoids (17 and 18). The structures of these compounds were characterized using various spectroscopic methods. All the isolated compounds were screened for adipogenesis inhibition at a concentration of 100 µM. Of these, compounds 1, 2, 4-9, 15, and 19 significantly reduced fat accumulation in 3T3-L1 adipocytes, especially compounds 4, 7, 9, and 19, showing 37.05 ± 0.95, 8.60 ± 0.41 15.82 ± 1.23, and 17.73 ± 1.28% lipid content, respectively, at a concentration of 100 µM. These findings provide experimental evidence that isolates from S. sieboldii extracts exert beneficial effects regarding the regulation of adipocyte differentiation.

Phytochemical investigation on the aerial parts of Veratrum versicolor f. viride Nakai and their biological activities.

Veratrum spp. have traditionally been used in folk medicine to treat various pathologies. In this study, nine compounds, comprising one simple phenolic compound (1), three stilbenoids (2-4), and five flavonoids (5-9), were isolated from the aerial parts of Veratrum versicolor f. viride Nakai. The structures of these compounds were elucidated by spectroscopic analyses and comparison with reported data. Together, all reported compounds were isolated from V. versicolor f. viride for the first time in the study. Among them, two flavone aglycone tricetins (7 and 9) have never been isolated from the genus Veratrum or the family Melanthiaceae. The ethanol extract and isolated compounds were assessed for their inhibitory effects on elastase, tyrosinase, and melanin synthesis. Compounds 5 and 7 inhibited elastase (IC50: 292.25 ± 14.39 and 800.41 ± 5.86 µM, respectively), whereas compounds 2-5 inhibited tyrosinase with IC50 values in the range of 6.42 ~ 51.19 µM, respectively. In addition, compounds 3-6 and 8 exhibited dose-dependent inhibition (70.4% ~ 91.0%) of melanogenesis at a concentration of 100 µM.

Spiraea prunifolia leaves extract inhibits adipogenesis and lipogenesis by promoting ß-oxidation in high fat diet-induced obese mice.

Spiraea prunifolia has been used in Korean traditional medicine to treat malaria, fever, and emetic conditions. Previous investigation reported that several parts of Spiraea prunifolia show various functional effects. However, the effect of Spiraea prunifolia leaves extract (SPE) on anti-obesity remains unclear. Therefore, we used a high-fat diet (HFD)-induced obese mouse model in this study to investigate the effects of SPE on adipogenesis, lipogenesis, and ß-oxidation. Oral administration of SPE in HFD-induced obese mice considerably reduced body weight, serum levels such as total cholesterol, triglyceride, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol, adipose tissue weight, and adipocyte cell size. Moreover, SPE significantly decreased protein expression levels of adipogenesis and lipogenesis related genes such as CCAAT/enhancer binding protein α, peroxisome proliferator-activated receptor γ, adipocyte protein 2, acetyl-CoA carboxylase, and fatty acid synthase in epididymal adipose tissues. SPE treatment induced the protein expression of carnitine palmitoyl transferase-1, which might have promoted phosphorylated AMP-activated protein kinase-medicated ß-oxidation. The present study reveals an anti-adipogenic, anti-lipogenic, ß-oxidation effects of SPE in vivo and represents AMP-activated protein kinase signaling as targets for SPE.

Improvement of Obesity and Dyslipidemic Activity of Amomum tsao-ko in C57BL/6 Mice Fed a High-Carbohydrate Diet.

Amomum tsao-ko Crevost et Lemaire (Zingiberaceae) is a medicinal herb found in Southeast Asia that is used for the treatment of malaria, abdominal pain, dyspepsia, etc. The aim of this study was to investigate the effect of an ethanol extract of Amomum tsao-ko (EAT) on obesity and hyperlipidemia in C57BL/6 mice fed a high-carbohydrate diet (HCD). First, the mice were divided into five groups (n = 6/group) as follows: normal diet, HCD, and HCD+EAT (100, 200, and 400 mg/kg/day), which were orally administered with EAT daily for 84 days. Using microcomputed tomography (micro-CT) analysis, we found that EAT inhibited not only body-weight gain, but also visceral fat and subcutaneous fat accumulation. Histological analysis confirmed that EAT decreased the size of fat tissues. EAT consistently improved various indices, including plasma levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein, high-density lipoprotein, atherogenic index, and cardiac risk factors, which are related to dyslipidemia-a major risk factor for heart disease. The contents of TC and TG, as well as the lipid droplets of HCD-induced hepatic accumulation in the liver tissue, were suppressed by EAT. Taken together, these findings suggest the possibility of developing EAT as a therapeutic agent for improving HCD-induced obesity and hyperlipidemia.

Wheat Bran Extract Regulates Mast Cell-Mediated Allergic Responses In Vitro and In Vivo.

In the present study the effects and molecular mechanisms of wheat bran (WB), the hard outer layer of the wheat kernel used in food ingredients, on mast cell-mediated allergic responses in vitro and in vivo were investigated. The water extract of WB inhibited degranulation and expression of allergic and inflammatory mediators such as tumor necrosis factor-α, cyclooxygenase-2 and inducible nitric oxide synthase in antigen-stimulated RBL-2H3 cells. These anti-allergic activities of WB were mediated by the inactivation of extracellular signal-regulated kinase and p38 mitogen-activated protein kinase, which play important roles in degranulation and expression of various allergic and inflammatory molecules. In agreement with its in vitro effects, WB inhibited immunoglobulin E (IgE)/antigen-induced and compound 48/80-induced anaphylactic reactions in vivo. Taken together, these findings suggest the pharmacological potential of WB in the regulation of allergic diseases, including allergic rhinitis, atopic dermatitis, asthma and anaphylaxis.

A novel role for α-viniferin in suppressing angiogenesis by blocking the VEGFR-2/p70S6K signaling pathway.

Angiogenesis plays important roles in pathological conditions such as cancer and inflammation as well as normal tissue development and homeostasis. Here, we investigated the effects and molecular mechanisms of α-viniferin, an oligostilbene isolated from Caragana sinica, on human umbilical vein endothelial cell responses in vitro and angiogenic sprouting in aortic rings ex vivo. α-viniferin treatment inhibited mitogen-induced HUVEC proliferation by retinoblastoma protein hypophosphorylation. In addition, α-viniferin suppressed mitogen-induced HUVEC adhesion, migration, invasion, and microvessel outgrowth. These anti-angiogenic activities of α-viniferin might be mediated through downregulation of cell cycle-related proteins, vascular endothelial growth factor receptor-2 (VEGFR-2), and matrix metalloproteinase-2. Furthermore, inactivation of VEGFR-2/p70 ribosomal S6 kinase signaling pathway was found to be involved in α-viniferin-mediated modulation of endothelial cell responses. Our results demonstrate the pharmacological functions and molecular mechanisms of α-viniferin in regulating angiogenesis, suggesting the therapeutic potential of α-viniferin to treat and prevent various angiogenesis-related diseases.

Combretum quadrangulare Extract Attenuates Atopic Dermatitis-Like Skin Lesions through Modulation of MAPK Signaling in BALB/c Mice.

Atopic dermatitis (AD) is a chronic inflammatory disease. Combretum quadrangulare (C. quadrangulare) is used as a traditional medicine to improve various pathologies in Southeast Asia. In this study, we investigated the effects of C. quadrangulare ethanol extract (CQ) on 1-chloro-2,4-dinitrobenzene (DNCB)-induced AD like skin lesions in BALB/c mice. After administration with CQ (100, 200, and 400 mg/kg) for 6 weeks, AD symptoms, protein expression, immunoglobulin E (IgE), thymus and activation-regulated chemokine (TARC), and ceramidase level were measured in skin lesions of DNCB-induced BALB/c mice. CQ group improved the dermatitis score, skin pH, transepidermal water loss (TEWL), and skin hydration. Furthermore, histological analysis revealed that CQ attenuated the increased epidermal thickness and infiltration of mast cells caused by DNCB. CQ also increased the expression of filaggrin, and reduced the expression of ceramidase, serum IgE level, and the number of eosinophils. CQ effectively inhibited cytokines and chemokines such as interleukin (IL)-6, IL-13, TARC, and thymic stromal lymphopoietin (TSLP) at the mRNA levels, as well as the activation of mitogen-activated protein kinase (MAPK), including extracellular signal-regulated kinase (ERK), c-jun N-terminal kinase (JNK), and p38 in the skin lesions. Taken together, these findings demonstrate that CQ may be an effective treatment of AD-like skin lesions by inhibiting the expression of inflammatory mediators via the MAPK signaling pathways.

Korean red ginseng water extract alleviates atopic dermatitis-like inflammatory responses by negative regulation of mitogen-activated protein kinase signaling pathway in vivo.

Atopic dermatitis (AD) is a chronic inflammatory skin disease. Korean red ginseng is a Korean traditional medicine. In this study, we estimated the effects of Korean red ginseng water extract (RGE) in the 1-chloro-2,4-dinitrobenzene (DNCB)-induced BALB/c mouse model which develops AD-like lesions. After RGE administration (100, 200, and 400 mg/kg) to DNCB-induced mice there were improvements in the dermatitis score and skin pH, a decrease in trans-epidermal water loss, and improved skin hydration. RGE also significantly inhibited eosinophil infiltration, increased filaggrin protein levels, and decreased serum IgE levels, epidermal thickness, mast cell infiltration, and ceramidase release. Compared with that in DNCB-induced mice, RGE effectively decreased the mRNA expression levels of interleukin-6 (IL-6), thymic stromal lymphopoietin (TSLP), and tumor necrosis factor-α (TNF-α), as well as the protein level of thymus and activation-regulated chemokine (TARC). These inhibitory RGE effects are mediated by inhibiting the phosphorylation of mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 MAPK. Furthermore, we confirmed that RGE suppresses interferon-γ (IFN-γ) and TNF-α-induced expression of macrophage-derived chemokine (MDC) and TARC genes in human keratinocyte (HaCaT) cells. Taken together, these results demonstrate that RGE may exert anti-atopic related to responses by suppression the expression of inflammatory mediators, cytokines, and chemokines via downregulation of MAPK signaling pathways, suggesting that RGE may be an effective therapeutic approach for prevention of AD-like disease.

Antihyperlipidemic Activity of Ligularia fischeri Extract in Mice Fed a High-Carbohydrate Diet.

Ligularia fischeri, indigenous to eastern Asia, has been used as a traditional herbal medicine. Ligularia fischeri reportedly possesses a number of biological activities such as antimutagenic, antioxidant, antigenotoxic, and anti-inflammation. This study demonstrated the effects of ethanol extracts of Ligularia fischeri (ELF) on a high-carbohydrate diet (HCD)-induced hyperlipidemia in C57BL/6 mice. The mice were divided into six groups (n = 7/group) as follows: normal diet, HCD, or HCD+ELF (100, 200, 400, and 800 mg/kg/day), which were orally administered daily for 12 weeks. Various lipid parameters and histological changes in liver and fat tissue were compared among the treatment and control groups. ELF remarkably reduced body weight gain and attenuated hyperlipidemia by improving the plasma levels of total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, atherogenic index, and cardiac risk factor. Moreover, ELF decreased the HCD-induced hepatic accumulation of lipid droplets and adipocyte hypertrophy. These regulatory effects of ELF appeared to be mediated through the phosphorylation of AMP-activated protein kinase, acetyl-CoA carboxylase, sterol regulatory element-binding protein-1c, and expression of fatty acid synthase. Taken together, these findings indicate a functional role for ELF in the regulation of HCD-induced obesity and hyperlipidemia.

Anti-melanogenic and anti-oxidant activities of ethanol extract of Kummerowia striata: Kummerowia striata regulate anti-melanogenic activity through down-regulation of TRP-1, TRP-2 and MITF expression.

Kummerowia striata (K. striata) is used as a traditional medicine for inflammation-related therapy. To determine whether it has beneficial anti-melanogenic and anti-oxidant activities, we investigated the biological activities of the ethanol extract of Kummerowia striata (EKS) using a variety of in vitro and cell culture model systems. The anti-melanogenic activity was assessed in B16F10 melanoma cells in terms of melanin synthesis and in vitro tyrosinase inhibitory activity. The anti-oxidant assays were performed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS). EKS showed strong anti-oxidant activities in DPPH and ABTS assays. The mRNA transcription levels and protein expression levels of tyrosinase, tyrosinase-related protein 1, tyrosinase-related protein 2, and microphthalmia-associated transcription factor decreased in a dose-dependent manner with EKS treatment. Additionally, EKS did not affect cell viability at different concentrations used in this study, indicating that the mechanism of action of EKS-mediated inhibition of melanin synthesis does not involve cytotoxicity. Also, we confirmed that p-coumaric acid and quercetin are important compounds for anti-melanogenesis and antioxidant properties of EKS. Collectively, our findings demonstrate for the first time that EKS possesses anti-melanogenic and anti-oxidant activities. Further evaluation and development of EKS as a functional supplement or cosmetic may be useful for skin whitening and reducing wrinkles.

Coixlachryside B: a new benzoxazinoid glycoside from the roots of Coix lachryma-jobi var. ma-yuen (Gramineae).

Coix lachryma-jobi L. var. ma-yuen has been a source of food and traditional folk medicine in some parts of Asia for thousands of years; however, the roots of this plant have not been phytochemically investigated. Herein, we report the isolation of a new benzoxazinoid glycoside, coixlachryside B (1), along with ten known compounds (2-11), from the roots of C. lachryma-jobi var. ma-yuen using a variety of chromatographic methods. Among the known compounds, the absolute configuration of compound 4 was determined. The structures of all compounds were elucidated by interpreting NMR spectroscopic data, and experimental and calculated electronic circular dichroism spectra.

Trigonostemon reidioides modulates endothelial cell proliferation, migration and tube formation via downregulation of the Akt signaling pathway.

Trigonostemon reidi`oides (TR) is used as a Thai traditional medicine for the treatment of drug addiction, asthma, food poisoning, constipation and snake bites. The present study investigated the effects and molecular mechanisms of the ethanolic extract of TR (ETR) on mitogen-induced human umbilical vein endothelial cells (HUVECs) responses, proliferation, adhesion, migration and tube formation. ETR treatment inhibited mitogen-induced HUVEC proliferation by downregulation of cell cycle-associated proteins, including cyclins and cyclin-dependent kinases, which induced retinoblastoma protein hypophosphorylation. The present study also demonstrated that ETR treatment suppressed mitogen-induced HUVEC adhesion, migration, invasion and tube formation, and that these anti-angiogenic activities were mediated by inactivation of mitogen-induced Akt and matrix metalloproteinase (MMP)-2, but not of extracellular signal-regulated kinase, p70 ribosomal S6 kinase or MMP-9. Collectively, the results of the present study suggested pharmacological functions and molecular mechanisms of ETR in regulating endothelial cell fates, and supported further evaluation and development of ETR as a potential therapeutic agent for the treatment and prevention of angiogenesis-associated diseases, including cancer.

Effects of Tribulus terrestris on monosodium iodoacetate­induced osteoarthritis pain in rats.

Tribulus terrestris L. (T. terrestris) has been used as a traditional medicine for the treatment of diuretic, lithontriptic, edema and urinary infections. Previous studies have indicated that it is effective in improving inflammation by regulating tumor necrosis factor­α (TNF)­α, interleukin (IL)­6, IL­10, nitric oxide (NO) and cyclooxygenase (COX)­2. However, the effects and mechanism of action of T. terrestris on osteoarthritis (OA) remain unknown. Therefore, the present study aimed to evaluate the effects of the ethanolic extract of T. terrestris (ETT) in a monosodium iodoacetate (MIA)­induced OA animal model. OA was induced in LEW/SSNHSD rats by intra­articular injection of MIA. Morphometric changes and parameters of the tibial trabecular bone were determined using micro­computed tomography. The molecular mechanisms of ETT in OA were investigated using reverse transcription­polymerase chain reaction, western blotting and gelatin zymogram analysis. Treatment with ETT attenuated MIA­induced OA, and this effect was mediated by the downregulation of NO synthase 2, COX­2, TNF­α and IL­6. Furthermore, the ETT­mediated attenuation of OA was also dependent on the expression of matrix metalloproteinases­2 and ­9. The results of the current study indicate that further evaluation of the mechanisms underlying the attenuation of MIA­induced OA by ETT are required, and may support the development of ETT as a potential therapeutic agent for the treatment of inflammatory diseases such as OA.

Anti-inflammatory effect of tribulusamide D isolated from Tribulus terrestris in lipopolysaccharide-stimulated RAW264.7 macrophages.

Tribulus terrestris (T. terrestris) has been used as a traditional medicine for the treatment of a variety of diseases, including inflammation, edema and hypertension. The aqueous and ethanol extracts of T. terrestris contain alkaloids, flavonoids, tannins, quinines and phenolic compounds. Tribulusamide D is a compound that has been isolated from the ethanol extract of T. terrestris. The present study investigated the anti­inflammatory effect of tribulusamide D on lipopolysaccharide (LPS)­stimulated RAW 264.7 macrophages. Tribulusamide D inhibited the production of LPS­induced nitric oxide and prostaglandin E2, by reducing the expression of inducible nitric oxide synthase and cyclooxygenase­2 expression, respectively. The expression of these genes associated with inflammation was determined using reverse transcription­polymerase chain reaction and western blot analysis. Furthermore, tribulusamide D reduced the expression of LPS­induced inflammatory cytokines, including interleukin (IL)­6, IL­10 and tumor necrosis factor­α. They were quantified using an enzyme­linked immunosorbent assay. In addition, the present study confirmed that the inhibitory effects of tribulusamide D on the inflammatory response were mediated through inactivation of mitogen­activated protein kinase p38 and inhibition of nuclear localization of nuclear factor­B, which were also determined by western blot analysis. To the best of our knowledge, the current study is the first to demonstrate that tribulusamide D exerts anti­inflammatory activity by altering the expression of inflammatory mediators and cytokines, indicating that tribulusamide D could be developed as a potential therapeutic agent for the treatment of inflammatory disorders.

Caragasinin C: a new oligostilbene from the roots of Caragana sinica.

A new oligostilbene, caragasinin C (1), and seven known compounds, betulinic acid (2), 4-hydroxybenzaldehyde (3), (‒)-medicarpin (4), wistin (5), (2E,4S)-4-hydroxy-2-nonenoic acid (6), pallidol (7), and (+)-α-viniferin (8), were isolated from the roots of Caragana sinica. The structure of caragasinin C was established on the basis of spectroscopic techniques, including HRESIMS, 1D and 2D-NMR.

A New Neolignan from Coix lachryma-jobi var. mayuen.

A new neolignan, named coixide A (1), along with fifteen known compounds, (7R,8S)-3'-demethyl-dehydrodiconiferyl alcohol-3'-O-ß-glucopyranoside (2), (7R,8)-3'-demethyl-9'-butoxy-dehydrodiconiferyl-3'-O-ß-glucopyranoside (3),adenosine (4), 2-O-caffeoyl isocitricacid (5), pseudolaroside A (6), 2-hydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one (7), 2-O-ß-glucopyranosyl-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (8), 2-O-ß-glucopyranosyl-4-hydroxy-7- methoxy-2H-1,4-benzoxazin-3(4H)-one (9), 2-O-ß-D-glucopyranosyl-7-hydroxy-2H-1,4-benzoxazin-3(4H)-one (10), p-coumaric acid ethyl ester (11), caffeic acid ethyl ester (12), p-coumaric acid (13), cis-N-p-coumaroyltyramine (14) trans-N-p-coumaroyltyramine (15), and coixol (16) have been isolated from Coix lachryma-jobi var. mayuen. Their chemical structures were elucidated by chemical evidence on the basis of spectroscopic and MS data, and as well as by comparison with those reported.

2,8-Decadiene-1,10-Diol Inhibits Lipopolysaccharide-Induced Inflammatory Responses Through Inactivation of Mitogen-Activated Protein Kinase and Nuclear Factor-κB Signaling Pathway.

Amomum tsao-ko (A. tsao-ko) has been used as a traditional medicine for the treatment of infectious and digestive disorders. In the present study, we report the anti-inflammatory activity and molecular mechanism of 2,8-decadiene-1,10-diol (DDO) isolated from the extract of A. tsao-ko in lipopolysaccharide-stimulated RAW 264.7 cells. DDO treatment inhibited the production of nitric oxide and prostaglandin E2 by downregulating inducible nitric oxide synthase and cyclooxygenase-2 expression, respectively. Moreover, DDO suppressed the production of pro-inflammatory cytokines such as interleukin-6 and tumor necrosis factor-α. These inhibitory effects of DDO on the expression of inflammatory proteins were found to be mediated through the inactivation of mitogen-activated protein kinases (MAPKs) such as extracellular signal-regulated kinase, c-Jun-N-terminal kinase and p38(MAPK), and inhibition of nuclear factor-κB (NF-κB) pathways including degradation of inhibitor of κB-α and nuclear localization of NF-κB. Taken together, these findings demonstrate the pharmacological roles and molecular mechanisms of DDO in regulating inflammatory responses, and suggest further evaluation and development of DDO as a potent therapeutic agent for the treatment of inflammatory disorders.

Ligularia fischeri inhibits endothelial cell proliferation, invasion and tube formation through the inactivation of mitogenic signaling pathways and regulation of vascular endothelial cadherin distribution and matrix metalloproteinase expression.

Ligularia fischeri (LF) has been used as an edible herb and traditional medicine for the treatment of inflammatory and infectious diseases. In the present study, we report the effects and molecular mechanism of the ethanolic extract of LF on cell proliferation, invasion and tube formation in human umbilical vein endothelial cells (HUVECs). LF-mediated inhibition of cell proliferation was accompanied by reduced expression of cell cycle-related proteins such as cyclin-dependent kinases (Cdks) and cyclins, leading to pRb hypophosphorylation and G1 phase cell cycle arrest. We also show that LF treatment inhibited cell invasion and tube formation in HUVECs. These anti-angiogenic activities of LF were associated with the inactivation of mitogenic signaling pathways, induction of vascular endothelial (VE)-cadherin distribution at cell-cell contacts and inhibition of matrix metalloproteinase (MMP) expression. Collectively, our findings demonstrate the pharmacological functions and molecular mechanisms of LF in regulating endothelial cell fates, and support further development as a potential therapeutic agent for the treatment and prevention of angiogenesis-related disorders including cancer.

Neolignan inhibitors of antigen-induced degranulation in RBL-2H3 cells from the needles of Pinus thunbergii.

The ethanolic extract of the needles of Pinus thunbergii was found to suppress antigen mediated degranulation of rat basophilic leukemia (RBL-2H3) cells. A new neolignan glycoside, named pinusthunbergiside A (1), as well as six known neolignan glycosides (2-7) were isolated from the ethanolic extract using bioassay-guided fractionation. Their structures were elucidated by a combination of 1D and 2D NMR, HRESI-MS, and circular dichroism (CD) data. Compounds 2-7 were found for the first time in this plant. The inhibitory effects of isolated constituents on the release of ß-hexosaminidase from RBL-2H3 cells were examined, and compounds 2, 3, 5, and 6 were found to show the inhibitory activity with IC50 values ranging between 52.3 and 75.3 µM.

Broussonetia kazinoki modulates the expression of VEGFR-2 and MMP-2 through the inhibition of ERK, Akt and p70S6K­dependent signaling pathways: Its implication in endothelial cell proliferation, migration and tubular formation.

Broussonetia kazinoki (BK) has been used as a traditional medicine to improve vision, as well as for inflammatory and infectious diseases. In the present study, we investigated the effects and molecular mechanism of the ethanolic extract of BK on cell proliferation, migration and tubular formation in vascular endothelial growth factor-A (VEGF-A)-treated human umbilical vein endothelial cells. BK treatment inhibited VEGF-A-stimulated endothelial cell proliferation through the downregulation of cell cycle-related proteins including cyclin-dependent kinases and cyclins. Moreover, BK treatment suppressed cell migration and tubular formation in response to VEGF-A. These anti-angiogenic activities of BK were associated with the inactivation of mitogenic signaling pathways including extracellular signal-regulated kinase, Akt and p70S6K, and the subsequent downregulation of VEGFR-2 and matrix metalloproteinase-2. Taken together, these findings suggest further evaluation and development of BK as a potential therapeutic agent for the treatment and prevention of angiogenesis-related diseases including cancer.