GTN057, a komaroviquinone derivative, induced myeloma cells' death in vivo and inhibited c-MET tyrosine kinase.

OBJECTIVE: Despite the development of newly developed drugs, most multiple myeloma (MM) patients with high-risk cytogenetic abnormalities such as t(4;14) or del17p relapse at anin early stage of their clinical course. We previously reported that a natural product,komaroviquinone (KQN), isolated from the perennial semi-shrub Dracocephalum komarovi, i.e., komaroviquinone (KQN) and its derivative GTN024 induced the apoptosis of MM cells by producing reactive oxygen species (ROS), but both exhibited significant hematological toxicity. Aim of this study is to clarify anti-tumor activity, safety and pharmacokinetics of GTN057, an optimization compound of KQN in vivo. METHODS: ICR/SCID xenograft model of KMS11, a t(4;14) translocation-positive MM cell line, was used for in vivo study. Mice pharmacokinetics of GTN057 and the degradation products were analyzed by LC-MS/MS. RESULTS: Herein, our in vitro experiments revealed that GTN057 is much less toxic to normal hematopoietic cells, induced the apoptosis of both MM cell lines andpatient samples, including those with high-risk cytogenetic changes. A xenograft model of a high-risk MM cell line demonstrated that GTN057 significantly delayed the tumor growth with no apparent hematological or systemic toxicities in vivo. The pathological examination of GTN057-treated tumors in vivoshowed revealed apoptosis of MM cells and anti-angiogenesis. In addition to the production of ROS, GTN057 inhibited the downstream signaling of c-MET, a receptor tyrosine kinase a receptor forand hepatocyte growth factor (HGF) receptor. Thus, GTN057 is less toxic and is able tomay be a candidate drug for treating MM patients, via multifunctional mechanisms. We have also extensively studied the pharmacologyical analysis of GTN057. The metabolites of GTN057, (e.g.,such as GTN054), may also have anti-tumorantitumor activity. CONCLUSION: Natural products or and their derivatives can could be good sources of antineoplastic drugs even for high-risk cancer.

Synthesis of the Carbohydrate Moiety of Glycoproteins from the Parasite Echinococcus granulosus and Their Antigenicity against Human Sera.

Stereocontrolled syntheses of biotin-labeled oligosaccharide portions containing the carbohydrate moiety of glycoprotein from Echinococcus granulosus have been accomplished. Trisaccharide Galß1-3Galß1-3GalNAcα1-R (A), tetrasaccharide Galα1-4Galß1-3Galß1-3GalNAcα1-R (B), and pentasaccharide Galα1-4Galß1-3Galß1-3Galß1-3GalNAcα1-R (C), (R = biotinylated probe) were synthesized by stepwise condensation and/or block synthesis by the use of 5-(methoxycarbonyl)pentyl 2-azido-4,6-O-benzylidene-2-deoxy-α-d-galactopyranoside as a common glycosyl acceptor. The synthesis of the tetrasaccharide and the pentasaccharide was improved from the viewpoint of reducing the number of synthetic steps and increasing the total yield by changing from stepwise condensation to block synthesis. Moreover, hexasaccharide E, which contains the oligosaccharide sequence which occurs in E. granulosus, was synthesized from trisaccharide D. We examined the antigenicity of these five oligosaccharides by an enzyme-linked immunosorbent assay (ELISA). Although compounds of C-E did not exhibit antigenicity against cystic echinococcosis (CE) patient sera, compounds B, D, and E showed good serodiagnostic potential for alveolar echinococcosis (AE).

Citrus Fruit-Derived Flavanone Glycoside Narirutin is a Novel Potent Inhibitor of Organic Anion-Transporting Polypeptides.

Organic anion-transporting polypeptides (OATPs) 1A2 and OATP2B1 are expressed in the small intestine and are involved in drug absorption. We identified narirutin, which is present in grapefruit juice, as a novel OATP inhibitor. The citrus fruit jabara also contains high levels of narirutin; therefore, we investigated the inhibitory potency of jabara juice against OATPs. The inhibitory effects of various related compounds on the transport activity of OATPs were evaluated using OATP-expressing HEK293 cells. The IC50 values of narirutin for OATP1A2- and OATP2B1-mediated transport were 22.6 and 18.2 µM, respectively. Other flavanone derivatives from grapefruit juice also inhibited OATP1A2/OATP2B1-mediated transport (order of inhibitory potency: naringenin > narirutin > naringin). Five percent jabara juice significantly inhibited OATP1A2- and OATP2B1-mediated transport by 67 ± 11 and 81 ± 5.5%, respectively (p < 0.05). Based on their inhibitory potency and levels in grapefruit juice, the inhibition of OATPs by grapefruit juice is attributable to both naringin and narirutin. Citrus × jabara, which contains narirutin, potently inhibits OATP-mediated transport.

A novel derivative (GTN024) from a natural product, komaroviquinone, induced the apoptosis of high-risk myeloma cells via reactive oxygen production and ER stress.

New drugs have significantly improved the survival of patients with multiple myeloma (MM), but the prognosis of MM patients with high-risk cytogenetic changes such as t(4; 14), t(14; 16) or del17p remains very poor. A natural product, komaroviquinone (KQN), was originally isolated from the perennial semi-shrub Dracocephalum komarovi and has anti-protozoal activity against Trypanosoma cruzi, the organism causing Chagas' disease. Here we demonstrate that a novel KQN-derivative, GTN024, has an anti-MM effect both in vitro and in vivo. GTN024 induced the apoptosis of MM cell lines including those with high-risk cytogenetic changes. GTN024 produced reactive oxygen species (ROS) and increased phosphorylated eIF2α. The ROS production and subsequent endoplasmic reticulum (ER) stress are thought to play a key role in GTN024-induced apoptosis, as the apoptosis was completely abrogated by anti-oxidant treatment. In a mouse xenograft model, an intraperitoneal injection of 20 mg/kg of GTN024 significantly delayed tumor growth. Hematological toxicity and systemic toxicity as indicated by weight loss were not observed. These results suggest that the novel KQN-derivative GTN024 could become a candidate drug for treating high-risk MM.

Taxodione induces apoptosis in BCR-ABL-positive cells through ROS generation.

Chronic myeloid leukemia (CML) and acute lymphoblastic leukemia (ALL) are hematopoietic malignancies caused by the constitutive activation of BCR-ABL tyrosine kinase. Although direct BCR-ABL inhibitors, such as imatinib, were initially successful in the treatment of leukemia, many patients developed drug resistance over time due to the gatekeeper mutation of BCR-ABL T315I. In the present study, we found that taxodione, a quinone methide diterpene isolated from Taxodium distichum, significantly induced apoptosis in human myelogenous leukemia-derived K562 cells, which were transformed by BCR-ABL. Taxodione reduced the activities of mitochondrial respiratory chain (MRC) complexes III and V, which appeared to induce the production of reactive oxygen species (ROS). N-acetylcysteine (NAC), an antioxidant agent, canceled taxodione-induced ROS production, reductions in MRC activities, particularly complex V, and apoptotic cell death. Furthermore, in K562 cells treated with taxodione, BCR-ABL and its major signaling molecules, such as STAT5 and Akt were sequestered in mitochondrial fraction, and their localization changes decrease their abilities to stimulate cell proliferation, suggesting that these actions seem to be a mechanism how taxodione functions as an anti-tumor drug. Strikingly, NAC canceled these taxodione-caused anti-cancer effects. Taxodione induced apoptosis in transformed Ba/F3 cells induced not only by BCR-ABL, but also T315I-mutated BCR-ABL through the generation of ROS. Collectively, the present results suggest that in the treatment of leukemia, taxodione has potential as a compound with high efficacy to overcome BCR-ABL T315I mutation-mediated resistance in leukemia cells.

Synthesis and biological evaluation of the natural product komaroviquinone and related compounds aiming at a potential therapeutic lead compound for high-risk multiple myeloma.

Alternatives of treatments for multiple myeloma (MM) have become increasingly available with the advent of new drugs such as proteasome inhibitors, thalidomide derivatives, histone deacetylase inhibitors, and antibody drugs. However, high-risk MM cases that are refractory to novel drugs remain, and further optimization of chemotherapeutics is urgently needed. We had achieved asymmetric total synthesis of komaroviquinone, which is a natural product from the plant Dracocephalum komarovi. Similar to several leading antitumor agents that have been developed from natural compounds, we describe the antitumor activity and cytotoxicity of komaroviquinone and related compounds in bone marrow cells. Our data suggested that komaroviquinone-related agents have potential as starting compounds for anticancer drug development.

Inhibitory effects of flavonoids extracted from Nepalese propolis on the LPS signaling pathway.

Flavonoids, particularly those derived from plants, harbor biological effects such as anti-inflammation and the inhibition of cancer progression. In the present study, we investigated the effects of 10 kinds of flavonoids isolated from Nepalese propolis on the LPS signaling pathway in order to clarify their anti-inflammatory activities. Five types of flavonoids: isoliquiritigenin, chrysin, 3',4'-dihydroxy-4-methoxydalbergione, 4-methoxydalbergion, and cearoin, markedly inhibited inflammatory responses including LPS-induced NO production by suppressing the expression of iNOS mRNA and LPS-induced mRNA expression of TNFα and CCL2. Their inhibitory effects on LPS-induced inflammatory responses correlated with the intensities of these flavonoids to suppress the LPS-induced activation of nuclear factor κB (NF-κB), an essential transcription factor for the mRNA expression of iNOS, TNFα, and CCL2. Among these flavonoids, 3',4'-dihydroxy-4-methoxydalbergione and 4-methoxydalbergion markedly inhibited the LPS-induced activation of IKK, thereby abrogating the degradation of IκBα and nuclear localization of NF-κB. On the other hand, isoliquiritigenin, chrysin, and cearoin failed to inhibit these signaling steps, but suppressed the transcriptional activity of NF-κB, which caused their anti-inflammatory effects. The results of the present study revealed that these five kinds of flavonoids are the components of Nepalese propolis that exhibit anti-inflammatory activities with a different regulatory mechanism for the activation of NF-κB.

Synthesis and Antigenicity against Human Sera of a Biotin-Labeled Oligosaccharide Portion of a Glycosphingolipid from the Parasite Echinococcus multilocularis.

Synthesis of a biotinylated analog of the carbohydrate portion of a glycosphingolipid from the parasite Echinococcus multilocularis has been achieved. We synthesized ß-D-Galp-(1→6)-ß-D-Galp-(1→6)-[α-L-Fucp-(1→3)]-ß-D-Galp-(1→R: biotin probe) (1) and compared the antigenicity by an enzyme linked immunosorbent assay (ELISA) with biotinylated trisaccharide α-D-Galp-(1→4)-ß-D-Galp-(1→3)-α-D-Galp-(1→R: biotin probe) (F), which has been shown to have significant antigenicity. Both of the oligosaccharides reacted with sera of alveolar echinococcosis (AE) patients, but showed different reactivity. Among the 60 sera of AE patients, more sera reacted with the linear sequence Galα1→4Galß1→3GalNAcα1→R of oligosaccharide (F) than for branched compound 1. Some sera showed high specificity to one of the compound, indicating that the antibodies in the sera of AE patients differ in their specificity to recognize carbohydrate sequences of glycosphingolipids. Our results demonstrate that both of the biotinylated oligosaccharides 1 and F have good serodiagnostic potential and are complementary to detect infections caused by the parasite Echinococcus multilocularis.

Two new lignans and melanogenesis inhibitors from Schisandra nigra.

An acetone extract from the stems of Schisandra nigra MAX. (Schisandraceae) exhibited significant inhibition of 3-isobutyl-1-methylxanthine (IBMX)-stimulated melanogenesis in murine B16 melanoma F10 cells. Fractionation and purification of the extract led to the isolation of two new tetrahydrofuran-type lignans, (+)-5-methoxyzuonin A (2) and kadlongirin C (3), along with eight known compounds (1, 4-10). The structures of the new compounds were determined by spectroscopic analyses. Of the isolated compounds (1, 3 -10), (+)-zuonin A (1) showed remarkable inhibition of melanogenesis at concentrations without cytotoxicity in B16 melanoma F10 cells. (+)-Zuonin A (1) did not inhibit tyrosinase; however, Western blot analysis revealed that it decreased protein levels of tyrosinase and tyrosinase-related proteins (TRP)-1 and TRP-2 without changing phosphorylation level of cAMP response element-binding protein.

Nepetaefuran and leonotinin isolated from Leonotis nepetaefolia R. Br. potently inhibit the LPS signaling pathway by suppressing the transactivation of NF-κB.

Leonotis nepetaefolia R. Br., also known as Klip Dagga or Lion's Ear, has traditionally been used as a folk medicine to treat inflammatory diseases such as rheumatism, bronchitis, and asthma; however, the components that exhibit its anti-inflammatory activity have not yet been identified. In the present study, we investigated the effects of three types of diterpenoids, nepetaefuran, leonotinin, and leonotin, which were isolated from L. nepetaefolia R. Br., on the LPS signaling pathway in order to elucidate the anti-inflammatory mechanism involved. Nepetaefuran more potently inhibited the LPS-induced production of NO and CCL2 than leonotinin by suppressing the expression of iNOS mRNA and CCL2 mRNA. On the other hand, leonotin failed to inhibit the production of NO and CCL2 induced by LPS. Although nepetaefuran and leonotinin had no effect on the LPS-induced degradation of IκBα or nuclear translocation of NF-κB p65, they markedly inhibited the transcriptional activity of NF-κB. Nepetaefuran and leonotinin also inhibited the transcriptional activity of the GAL4-NF-κB p65 fusion protein. On the other hand, nepetaefuran, leonotinin and leonotin did not affect the LPS-induced activation of MAP kinase family members such as ERK, p38, and JNK. In addition, inhibitory effect of nepetaefuran and leonotinin on NF-κB activation is well correlated with their ability to induce activation of Nrf2 and ER stress. Taken together, these results demonstrated that nepetaefuran and leonotinin could be the components responsible for the anti-inflammatory activity of L. nepetaefolia R. Br. by specifically inhibiting the LPS-induced activation of NF-κB.

Anti-inflammatory activity of flavonoids in Nepalese propolis is attributed to inhibition of the IL-33 signaling pathway.

Propolis has been used in folk medicine to improve health and prevent inflammatory diseases; however, the components that exhibit its anti-inflammatory activity remain unknown. We herein investigated the effects of flavonoids isolated from Nepalese propolis on the IL-33 signaling pathway to clarify the anti-inflammatory mechanism involved. Of the 8 types of flavonoids isolated from Nepalese propolis, 4 types of compounds, such as 3',4'-dihydroxy-4-methoxydalbergione, 4-methoxydalbergion, cearoin, and chrysin, markedly inhibited the IL-33-induced mRNA expression of inflammatory genes including IL-6, TNFα and IL-13 in bone marrow-derived mast cells (BMMC). These four flavonoids also inhibited the IL-33-induced activation of nuclear factor κB (NF-κB), which was consistent with their inhibitory effects on cytokine expression. The effects of these flavonoids are attributed to inhibition of IL-33-induced activation of IKK, which leads to the degradation of IκBα and nuclear localization of NF-κB. On the other hand, other flavonoids isolated from Nepalese propolis, such as isoliquiritigenin, plathymenin, 7-hydroxyflavanone, and (+)-medicarpin, had no effect on the IL-33 signaling pathway or cytokine expression. Therefore, these results indicate that 3',4'-dihydroxy-4-methoxydalbergione, 4-methoxydalbergion, cearoin, and chrysin are the substances responsible for the anti-inflammatory activity of Nepalese propolis.

Biochemical and biophysical properties of a novel homoisoflavonoid extracted from Scilla persica HAUSSKN.

In this study isolation and structural elucidation of a homoisoflavonoid, 3-(3',4'-dihydroxybenzyl)-8-hydroxy-5,7-dimethoxychroman-4-one (Scillapersicone 1), is reported from Scilla persica HAUSSKN. The structure was solved by a single crystal X-ray analysis. The unit cell parameters are a=11.7676 (2)Å, b=20.1174 (4)Å, c=7.8645 (9)Å, ß=93.544 (2)°, V=1858.23 (7)Å(3), monoclinic space group P21/c and four symmetry equivalent molecules in an unit cell. The structure was consistent with the UV, IR, 1D and 2D NMR, HRFAB-MS data. The optimized molecular geometry agrees closely that obtained from the single crystal X-ray crystallography. Furthermore, cytotoxicity of this compound was evaluated by MTT assay on AGS and WEHI-164 cancerous cell lines.

New diterpenoids with estrogen sulfotransferase inhibitory activity from Leonurus sibiricus L.

Four new diterpenoids (1-4), along with eight known diterpenoids (5-12) were isolated from the acetone extract of Leonurus herb (aerial parts of Leonurus sibiricus L.). The structures of the compounds were determined by spectroscopic methods. Among the isolated compounds, compounds 2, 3, 8, 9 and 10 showed inhibitory activity against human liver cytosol estrogen sulfotransferase (E-ST), which plays a key role in the maintenance of cellular estrogen levels. Compound 2 showed the strongest activity with an IC50 value of 7.9 µM, which is comparable to the activity of the positive control, meclofenamic acid (IC50 5.4 µM).

Quantitative analysis of anti-inflammatory activity of orengedokuto: importance of combination of flavonoids in inhibition of PGE2 production in mouse macrophage-like cell line J774.1.

Orengedokuto is a Kampo formula which has been used for removing "heat" and "poison" to treat inflammation, hypertension, gastrointestinal disorders, and liver and cerebrovascular diseases. In this report, we quantitatively analyzed the anti-inflammatory effect of the component crude drugs of orengedokuto and their constituents, using inhibition of prostaglandin E2 (PGE2) production in the murine macrophage-like cell line J774.1. First, we compared PGE2 production inhibitory activities of extracts of combinations of the component crude drugs, which showed that the activity could be ascribed to Scutellaria Root. Next, as baicalin (1), one of the major constituents of Scutellaria Root, did not show any activity, and baicalein (2), the aglycon of 1, showed only weak activity (IC50 92 µM), a hot-water extract of Scutellaria Root was fractionated under the guidance of the activity to give wogonin (3) (IC50 28 µM), 6-methoxywogonin (4) (IC50 7.2 µM) and oroxylin A (5) (IC50 45 µM) from the most active fraction. However, the activities of these compounds at concentrations equivalent to those in the extract were weaker than that of the extract, and none of these compounds alone could explain the activity of the extract. Therefore, we examined the activity of combinations of compounds 2-5. Comparison of all combinations of the four compounds in a ratio which is the same as in the extract revealed that wogonin (3) had an essential role in the activity, and a combination of baicalein (2) and wogonin (3), together with 6-methoxywogonin (4) or oroxylin A (5), was necessary to show activity equivalent to that of the extract.

Collagenase inhibitors from Viola yedoensis.

Fractionation of acetone and methanol extracts of Viola yedoensis, under the guidance of inhibition against Clostridium histolyticum collagenase (ChC), resulted in the isolation of esculetin (1) (IC(50) 12 µM) and scopoletin (2) (IC(50) 1.8 µM) as the active constituents, together with trans-p-coumaric acid (3), cis-p-coumaric acid (4), 3-O-ß-D-glucosyl-7-O-α-L-rhamnosylkaempferol (5), rutin (6), isovitexin (7), isoorientin (8), vicenin-2 (9), isoscoparin (10), vanillic acid (11) and adenosine (12). Modification of phenolic hydroxy groups of 1 showed that small O-alkyl groups largely increased the activity, whereas larger O-alkyl groups decreased the activity, and 6,7-dimethoxycoumarin (scoparone 13) potently inhibited ChC (IC(50) 24 nM).

Sulfatides inhibit adhesion, migration, and invasion of murine melanoma B16F10 cell line in vitro.

Endogenous sulfatide, such as 3-sulfated galactosylceramide (3-sulfatide) has been reported to be involved in neuronal development and regulation of tumor cell metastasis. Recently, a new 6-sulfated glucosylceramide (6-sulfatide) has been isolated from the ascidian, Ciona intestinalis. To determine the antitumor function of the new sulfatide, we examined the effects of synthetic 6-sulfatide and 3-sulfatide on the metastatic features of a murine melanoma cell line, B16F10. Both sulfatides significantly inhibited the adhesion of melanoma cells onto fibronectin-coated tissue plates and, the motility and invasion of the cells, with 6-sulfatide showing stronger inhibitory activities. In addition, both sulfatides inhibited α(5)-, and ß(1)- but not α(v)- or ß(3)-integrin expression. Furthermore, these sulfatides inhibited the activation of focal adhesion kinase, Akt, and extracellular signal-regulated kinase signaling pathways, which are thought to be important for cell migration and invasion. Therefore, these sulfatides may serve as promising drug candidates for the treatment of cancer metastasis.

Improvement of benzylisoquinoline alkaloid productivity by overexpression of 3'-hydroxy-N-methylcoclaurine 4'-O-methyltransferase in transgenic Coptis japonica plants.

Coptis japonica (Cj) rhizomes are used as a crude drug for gastroenteritis, since they accumulate antimicrobial berberine. Berberine also shows various useful bioactivities, including cholesterol-lowering activity. Unfortunately, Cj is a slow-growing plant and more than 5 years are required to obtain a crude drug suitable for the Japanese Pharmacopoeia. To improve alkaloid productivity, we overexpressed the 3'-hydroxy-N-methylcoclaurine 4'-O-methyltransferase (4'OMT) gene in Cj. We established the transgenic plant (named CjHE4') by introducing one copy of Cj4'OMT by Agrobacterium-mediated transformation. The successful overexpression of 4'OMT was confirmed in all tissues of CjHE4' by real-time polymerase chain reaction (PCR) analysis. HPLC analysis revealed that the berberine content of CjHE4' leaves and roots cultivated for 4 months was increased to 2.7- and 2.0-fold, respectively, compared with non-transgenic wild-type (CjWT), and these inductions of alkaloids were stable for at least 20 months. Furthermore, in CjHE4' cultivated for 20 months, the berberine content in medicinal parts, stems and rhizomes was significantly increased (1.6-fold). As a consequence, increased amounts of alkaloids in CjHE4' resulted in the improvement of berberine yields (1.5-fold), whereas CjHE4' showed slower growth than CjWT. These results indicated that 4'OMT is one of the key-step enzymes in berberine biosynthesis and is useful for metabolic engineering in Cj.

Anticarcinogenic compounds in the Uzbek medicinal plant, Helichrysum maracandicum.

An ethanol extract of Helichrysum maracandicum showed antiproliferative activity against cultured cells of SENCAR mouse in an in vitro assay, and activity-guided fractionation of the extract resulted in the isolation of isosalipurposide as an active substance. Naringenin chalcone, the aglycone of isosalipurposide, also showed strong antiproliferative activity. An in vivo assay of two-stage carcinogenesis on mouse skin revealed that epidermal application of isosalipurposide resulted in delayed formation of papillomas. Western blot analysis showed that the expression of p38 mitogen-activated protein kinase was suppressed by the administration of naringenin chalcone or isosalipurposide, which might be related to the anticarcinogenic activity.

An unusual sesquiterpene derivative from Ferula kuhistanica.

An unusual new sesquiterpene derivative, kuhistaferone (1), was isolated from the fruits of the Uzbekistan medicinal plant Ferula kuhistanica. The structure of 1 was established on the basis of spectroscopic evidence. Compound 1 showed moderate cytotoxicity against the human colon tumor cell line HCT116.

Monoterpene hydroperoxides with trypanocidal activity from Chenopodium ambrosioides.

Four monoterpene hydroperoxides were isolated from aerial parts of Chenopodium ambrosioides along with ascaridole (1), the anthelmintic principle of this plant, as anti-trypanosomal compounds. The structures of these monoterpenes were determined to be (-)-(2S,4S)- and (-)-(2R,4S)-p-mentha-1(7),8-dien-2-hydroperoxide (2a and 3a) and (-)-(1R,4S)- and (-)-(1S,4S)-p-mentha-2,8-dien-1-hydroperoxide (4a and 5a) on the basis of spectroscopic methods and chemical correlations. In vitro trypanocidal activities of ascaridole (1) and these hydroperoxides (2a-5a) against epimastigotes of Trypanosoma cruzi were 23, 1.2, 1.6, 3.1, and 0.8 microM, respectively. Fresh leaves of C. ambrosioides also contained isomeric hydroperoxides 6a and 7a, and the content ratio of 2a-7a suggested that these hydroperoxides were formed through the singlet-oxygen oxidation of limonene.