Preclinical evaluation of JAK1/2 inhibition by ruxolitinib in a murine model of chronic graft-versus-host disease.

The objective of this study was to examine the therapeutic effect of ruxolitinib, an orally administered selective Janus kinase (JAK) 1/2 inhibitor, on chronic graft-versus-host disease (cGVHD) using a murine model of sclerodermatous GVHD (scl-GVHD). Compared with scl-GVHD controls, ruxolitinib-treated recipients had scl-GVHD of significantly attenuated clinical and pathological severity in the skin and decreased frequencies of effector cells, CD4+ T cells, and CD11b+ macrophage/monocytes. Regulatory CD4+ Foxp3+ T cells were expanded whereas interferon-γ (IFN-γ)-producing CD4+ T cells were significantly decreased in ruxolitinib-treated recipients. Ruxolitinib suppressed not only the production of IFN-γ from CD4+ T cells and monocyte chemoattractant protein 1 (MCP-1) from CD11b+ macrophage/monocytes, but also the proliferation of these cells in vitro. Levels of both cytokines (IFN-γ and MCP-1) were also reduced in the spleen and skin of ruxolitinib-treated recipients in vivo. IFN-γ-induced MCP-1 production and migration of RAW 264.7 cells, a macrophage cell line, were inhibited by ruxolitinib. However, supplementation with MCP-1 restored this effect of ruxolitinib. In addition, blocking JAK-STAT signaling using ruxolitinib reduced the activation of STAT1 in stimulated immune effector cells. Taken together, these results suggest that ruxolitinib can prevent scl-GVHD by suppressing IFN-γ produced by T cells and MCP-1 expression in macrophage/monocytes via inhibition of JAK-STAT signaling.

Comparison of Myeloablative (CyTBI, BuCy) versus Reduced-Intensity (FluBu2TBI400) Peripheral Blood Stem Cell Transplantation in Acute Myeloid Leukemia Patients with Pretransplant Low WT1 Expression.

Relapse is a major concern with reduced-intensity conditioning. We analyzed 257 patients with acute myeloid leukemia (AML) who received allogeneic stem cell transplantation (SCT) and fulfilled the following criteria: intermediate- or poor-risk disease by National Comprehensive Cancer Network guidelines (2017, version 3), in first complete remission (CR1) at SCT, received either myeloablative conditioning (MAC; busulfan plus cyclophosphamide or cyclophosphamide plus total body irradiation) or reduced-intensity conditioning (RIC; FluBu2TBI400) peripheral blood SCT from 8/8 matched sibling or unrelated donor, and having bone marrow Wilms tumor gene 1 (WT1) expression results before transplant. We and other groups serially published a predictive value for pretransplant WT1 expression in patients with AML to identify patients at higher risk of relapse. Among the total 257 patients, 191 (74.3%) and 66 (25.7%) patients received MAC and RIC transplants, respectively. WT1 ≥250 copies/104ABL was defined as WT1high. WT1high before SCT was found to be an independent prognostic factor for inferior overall survival (OS), disease-free survival (DFS), and higher cumulative incidence of relapse (CIR). There were 201 patients with WT1 low expression based upon pretransplant analysis. There was no significant difference in OS, DFS, CIR, and nonrelapse mortality between MAC and RIC patients. To conclude, post-transplant survival or relapse was not different by conditioning intensity in AML CR1 patients whose WT1 level was below 250 copies per 104ABL at transplantation.

310 nm UV-LEDs attenuate imiquimod-induced psoriasis-like skin lesions in C57BL/6 mice and inhibit IL-22-induced STAT3 expression in HaCaT cells.

Ultraviolet light-emitting diodes (UV-LEDs) are a novel light source for phototherapy. This study aimed to evaluate the therapeutic effects of UV-LEDs on psoriasis. Importantly, 310 nm UV-LEDs have not been studied in psoriasis in vitro and in vivo. Effects due to 310 nm UV-LED and 311 nm narrowband ultraviolet B (NBUVB) irradiation were compared for suppressing IL-22-induced activation of STAT3 expression using cell viability assay, western blotting, and immunocytochemistry. C57BL/6 mice were topically treated with imiquimod (IMQ) for 6 consecutive days and degenerative changes were observed. Test groups were irradiated with a 310 nm UV-LED and 311 nm NBUVB. Phenotypic observations, histopathological examinations, and ELISA were conducted with skin and blood samples. STAT3-dependent IL-22 signalling and effects in keratinocytes are negatively regulated by the 310 nm UV-LED, which significantly ameliorated IMQ-induced psoriasis-like dermatitis development and reduced Th17 cytokine levels (IL-17A, IL-22) in serum and dorsal skin. Histopathological findings showed decreases in epidermal thickness and inflammatory T-cell infiltration in the UV-LED-irradiated groups. Quantitative PCR confirmed a UV radiation energy-dependent decrease in IL-17A and IL-22 mRNA levels. The results demonstrated that UV-LEDs had anti-inflammatory and immunoregulatory effects. So, UV-LED phototherapy inhibits psoriasis development by suppressing STAT3 protein and inflammatory cytokines and could be useful in treating psoriasis.

Induction of SIRT1 by melatonin improves alcohol-mediated oxidative liver injury by disrupting the CRBN-YY1-CYP2E1 signaling pathway.

Alcoholic liver disease is the most prevalent chronic liver disease. Melatonin is known to control many vital processes. Here, we explored a novel molecular mechanism by which melatonin-induced SIRT1 signaling protects against alcohol-mediated oxidative stress and liver injury. Gene expression profiles and metabolic changes were measured in liver specimens of mice and human subjects. Expression levels of Cb1r, Crbn, Btg2, Yy1, pro-inflammatory cytokines, and Cyp2e1 were significantly enhanced in chronic alcohol-challenged mice and human subjects. Levels of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), hepatic CYP2E1 protein, and reactive oxygen species (ROS) were elevated in alcohol-fed WT mice but not in Cb1r antagonist-treated, Crbn null, or Yy1-silenced mice. Importantly, alcohol-induced Yy1 and Cyp2e1 expression, ROS amount, and liver injury were markedly diminished by melatonin treatment and the transduction of Sirt1 in mice, whereas this phenomenon was prominently ablated by silencing of Sirt1. Notably, SIRT1 physically interacted with YY1 and attenuated YY1 occupancy on the Cyp2e1 gene promoter. Melatonin-SIRT1 signaling ameliorates alcohol-induced oxidative liver injury by disrupting the CRBN-YY1-CYP2E1 signaling pathway. The manipulation of CRBN-YY1-CYP2E1 signaling network by the melatonin-SIRT1 pathway highlights a novel entry point for treating alcoholic liver disease.

Biostimulatory effects of polydioxanone, poly-d, l lactic acid, and polycaprolactone fillers in mouse model.

BACKGROUND: Numerous fillers are increasingly used for augmentation of volume loss and relaxation of facial wrinkles. Collagen stimulators are the latest next-generation dermal fillers that can induce neocollagenesis. To investigate biophysical characteristics, safety, and efficacy of newly developed polydioxanone (PDO) filler in comparison with poly-l lactic acid (PLLA) and polycaprolactone (PCL) fillers. METHODS: In vitro assay, morphology of particles, and rheological property of fillers were measured. A total of 24 female hairless mice (SKH1-Hrhr ) were randomly divided into three groups and injected with PDO, PLLA, or PCL fillers. Durability of fillers was assessed at 0, 3 days, and 1, 4, 8, 12 weeks after injection using folliscope and PRIMOS. To determine biocompatibility and neocollagenesis, histologic evaluation was performed at 1, 4, 8, and 12 weeks after injection. Efficacy was also evaluated based on skin surface roughness changes using PRIMOS in a hairless mouse photoaging model. RESULTS: In the particle morphology test, PDO microspheres had an irregular surface and were spherical and uniformly sized. PDO filler demonstrated similar neocollagenesis and inflammatory response to other collagen stimulators. PDO filler showed better biodegradability than PLLA and PCL fillers. In the hairless mouse photoaging model, there was a statistically significant decrease in skin surface roughness after PDO filler injection. CONCLUSIONS: Our data suggest that newly developed collagen stimulating PDO filler might be a safe and effective option for correction of volume loss and rejuvenation of photoaging skin.

4-Hydroxy-7-methyl-3-phenylcoumarin Suppresses Aflatoxin Biosynthesis via Downregulation of aflK Expressing Versicolorin B Synthase in Aspergillus flavus.

Naturally occurring coumarins possess antibacterial and antifungal properties. In this study, these natural and synthetic coumarins were used to evaluate their antifungal activities against Aspergillus flavus, which produces aflatoxins. In addition to control antifungal activities, antiaflatoxigenic properties were also determined using a high-performance liquid chromatography in conjunction with fluorescence detection. In this study, 38 compounds tested and 4-hydroxy-7-methyl-3-phenyl coumarin showed potent antifungal and antiaflatoxigenic activities against A. flavus. Inhibitory mode of antiaflatoxigenic action by 4-hydroxy-7-methyl-3-phenyl coumarin was based on the downregulation of aflD, aflK, aflQ, and aflR in aflatoxin biosynthesis. In the cases of coumarins, antifungal and aflatoxigenic activities are highly related to the lack of diene moieties in the structures. In structurally related compounds, 2,3-dihydrobenzofuran exhibited antifungal and antiaflatoxigenic activities against A. flavus. The inhibitory mode of antiaflatoxigenic action by 2,3-dihydrobenzofuran was based on the inhibition of the transcription factor (aflS) in the aflatoxin biosynthesis pathway. These potent inhibitions of 2,3-dihydrobenzofuran and 4-hydroxy-7-methyl-3-phenyl coumarin on the Aspergillus growth and production of aflatoxins contribute to the development of new controlling agents to mitigate aflatoxin contamination.

Melatonin ameliorates alcohol-induced bile acid synthesis by enhancing miR-497 expression.

Alcoholic liver disease is a major cause of chronic liver disease worldwide, and cannabinoid receptor type 1 (CB1R) is involved in a diverse metabolic diseases. B-cell translocation gene 2 (BTG2) and yin yang 1 (YY1) are a potent regulator of biological conditions. Melatonin plays a crucial role in regulating diverse physiological functions and metabolic homeostasis. MicroRNAs are key regulators of various biological processes. Herein, we demonstrate that melatonin improves bile acid synthesis in the liver of alcohol-fed mice by controlling miR-497 expression. The level of bile acid and the expression of Cb1r, Btg2, Yy1, and bile acid synthetic enzymes were significantly elevated in the livers of Lieber-DeCarli alcohol-fed mice. The overexpression of Btg2 enhanced Yy1 gene expression and bile acid production, whereas disrupting the CB1R-BTG2-YY1 cascade protected against the bile acid synthesis caused by alcohol challenge. We identified an alcohol-mediated YY1 binding site on the cholesterol 7α-hydroxylase (Cyp7a1) gene promoter using promoter deletion analysis and chromatin immunoprecipitation assays. Notably, melatonin attenuated the alcohol-stimulated induction of Btg2, Yy1 mRNA levels and bile acid production by promoting miR-497. Overexpression of a miR-497 mimic dramatically diminished the increase of Btg2 and Yy1 gene expression as well as bile acid production by alcohol, whereas this phenomenon was reversed by miR-497 inhibitor. These results demonstrate that the upregulation of miR-497 by melatonin represses alcohol-induced bile acid synthesis by attenuating the BTG2-YY1 signaling pathway. The melatonin-miR497 signaling network may provide novel therapeutic targets for the treatment of hepatic metabolic dysfunction caused by the alcohol-dependent pathway.

Rostral Agranular Insular Cortex Lesion with Motor Cortex Stimulation Enhances Pain Modulation Effect on Neuropathic Pain Model.

It is well known that the insular cortex is involved in the processing of painful input. The aim of this study was to evaluate the pain modulation role of the insular cortex during motor cortex stimulation (MCS). After inducing neuropathic pain (NP) rat models by the spared nerve injury method, we made a lesion on the rostral agranular insular cortex (RAIC) unilaterally and compared behaviorally determined pain threshold and latency in 2 groups: Group A (NP + MCS; n = 7) and Group B (NP + RAIC lesion + MCS; n = 7). Also, we simultaneously recorded neuronal activity (NP; n = 9) in the thalamus of the ventral posterolateral nucleus and RAIC to evaluate electrophysiological changes from MCS. The pain threshold and tolerance latency increased in Group A with "MCS on" and in Group B with or without "MCS on." Moreover, its increase in Group B with "MCS on" was more than that of Group B without MCS or of Group A, suggesting that MCS and RAIC lesioning are involved in pain modulation. Compared with the "MCS off" condition, the "MCS on" induced significant threshold changes in an electrophysiological study. Our data suggest that the RAIC has its own pain modulation effect, which is influenced by MCS.

B-cell translocation gene 2 promotes hepatic hepcidin production via induction of Yin Yang 1.

Hepcidin is a peptide hormone secreted in the liver and plays a key role in maintaining iron homeostasis. Here, we demonstrate that B-cell translocation gene 2 (BTG2) is a key player in hepatic hepcidin regulation via induction of Yin Yang 1 (YY1). Hepatic hepcidin gene expression significantly enhanced by fasting states and glucagon exposure led to induction of gluconeogenic gene expression, and elevated serum hepcidin production in mice. Notably, overexpression of BTG2 using adenoviral system (Ad-BTG2) significantly elevated serum hepcidin levels via a significant induction of YY1 gene transcription. Immunoprecipitation studies demonstrated that BTG2 physically interacted with YY1 and recruited on the hepcidin gene promoter. Finally, ablation of hepatic BTG2 gene by gene silencing markedly attenuated the elevation of serum hepcidin production along with YY1 and hepcidin mRNA expression in fasting state. Likewise, forskolin (FSK)-stimulated hepcidin promoter activity was dramatically disrupted by endogenous BTG2 knockdown. Overall, our current study provides a novel molecular mechanism of BTG2-mediated induction of hepcidin gene expression, thereby contributing to a better understanding of the hepatic hepcidin production involved in iron homeostasis.

Gastroprotective efficacy and safety evaluation of scoparone derivatives on experimentally induced gastric lesions in rodents.

This study investigated the gastroprotective efficacy of synthesized scoparone derivatives on experimentally induced gastritis and their toxicological safety. Six scoparone derivatives were synthesized and screened for gastroprotective activities against HCl/ethanol- and indomethacin-induced gastric ulcers in rats. Among these compounds, 5,6,7-trimethoxycoumarin and 6,7,8-trimethoxycoumarin were found to have gastroprotective activity greater than the standard drug rebamipide; 6-methoxy-7,8-methylenedioxycoumarin, 6-methoxy-7,8-(1-methoxy)-methylenedioxycoumarin, 6,7-methylenedioxycoumarin, and 6,7-(1-methoxy)-methylenedioxycoumarin were found to be equipotent or less potent that of rebamipide. Pharmacological studies suggest that the presence of a methoxy group at position C-5 or C-8 of the scoparone's phenyl ring significantly improves gastroprotective activity, whereas the presence of a dioxolane ring at C-6, C-7, or C-8 was found to have decreased activity. In order to assess toxicological safety, two of the potent gastroprotective scoparone derivatives-5,6,7-trimethoxycoumarin and 6,7,8-trimethoxycoumarin-were examined for their acute toxicity in mice as well as their effect on cytochrome P450 (CYP) enzyme activity. These two compounds showed low acute oral toxicity in adult male and female mice, and caused minimal changes to CYP3A4 and CYP2C9 enzyme activity. These results indicate that compared to other scoparone derivatives, 5,6,7-trimethoxycoumarin and 6,7,8-trimethoxycoumarin can improve gastroprotective effects, and they have low toxicity and minimal effects on drug-metabolizing enzymes.

Recent advances in treatment of aplastic anemia.

Recent advances in the treatment of aplastic anemia (AA) made most of patients to expect to achieve a long-term survival. Allogeneic stem cell transplantation (SCT) from HLA-matched sibling donor (MSD-SCT) is a preferred first-line treatment option for younger patients with severe or very severe AA, whereas immunosuppressive treatment (IST) is an alternative option for others. Horse anti-thymocyte globuline (ATG) with cyclosporin A (CsA) had been a standard IST regimen with acceptable response rate. Recently, horse ATG had been not available and replaced with rabbit ATG in most countries. Subsequently, recent comparative studies showed that the outcomes of patients who received rabbit ATG/CsA were similar or inferior compared to those who received horse ATG/CsA. Therefore, further studies to improve the outcomes of IST, including additional eltrombopag, are necessary. On the other hand, the upper age limit of patients who are able to receive MSD-SCT as first-line treatment is a current issue because of favorable outcomes of MSD-SCT of older patients using fludarabine-based conditioning. In addition, further studies to improve the outcomes of patients who receive allogeneic SCT from alternative donors are needed. In this review, current issues and the newly emerging trends that may improve their outcomes in near futures will be discussed focusing the management of patients with AA.

Inhibition of indoleamine 2,3-dioxygenase by stereoisomers of 1-methyl tryptophan in an experimental graft-versus-tumor model.

Indoleamine 2,3-dioxygenase (IDO) is a rate-limiting enzyme in tryptophan catabolism that plays an important role in the induction of immune tolerance. Its role in graft-versus-tumor effect after allogeneic stem cell transplantation (allo-SCT) remains unclear. Using a murine graft-versus-tumor model of reduced-intensity allo-HSCT followed by donor leukocyte infusion (DLI), we examined the role of IDO inhibition. Two stereoisomers of 1-methyl tryptophan (1-MT), a small-molecule inhibitor of IDO, reduced the growth of inoculated tumor in the mice that received DLI and had higher expression of IDO1 and IFNγ. However, L-1MT, but not D-1MT, mitigated tumor growth in mice that did not receive DLI and did not express IDO1 and IFNγ. Accordingly, both stereoisomers reduced plasma kynurenine concentrations early after DLI and enhanced in vitro cytotoxic lymphocyte function after allogeneic mixed lymphocyte reaction. Furthermore, L-1MT was more efficient in causing direct cytotoxic effects than D-1MT. Our results suggest that IDO inhibition can benefit anti-tumor therapy in the setting of reduced-intensity allo-SCT using DLI.

Acaricidal activities against house dust mites of spearmint oil and its constituents.

The aim of this study was to evaluate the acaricidal activities of spearmint oil and carvone derivatives against house dust mites using contact and fumigant toxicity bioassays to replace benzyl benzoate as a synthetic acaricide. Based on the LD50 values, the contact toxicity bioassay revealed that dihydrocarvone (0.95 and 0.88 µg/cm2) was 7.7 and 6.8 times more toxic than benzyl benzoate (7.33 and 6.01 µg/cm2) against Dermatophagoides farinae and Dermatophagoides pteronyssinus, respectively, followed by carvone (3.78 and 3.23 µg/cm2), spearmint oil (5.16 and 4.64 µg/cm2), carveol (6.00 and 5.80 µg/cm2), and dihydrocarveol (8.23 and 7.10 µg/cm2). Results of the fumigant toxicity bioassay showed that dihydrocarvone (2.73 and 2.16 µg/cm2) was approximately 4.0 and 4.8 times more effective than benzyl benzoate (11.00 and 10.27 µg/cm2), followed by carvone (6.63 and 5.78 µg/cm2), carveol (7.58 and 7.24 µg/cm2), spearmint oil (9.55 and 8.10 µg/cm2), and dihydrocarveol (9.79 and 8.14 µg/cm2). Taken together, spearmint oil and carvone derivatives are a likely viable alternative to synthetic acaricides for managing house dust mites.

Antimicrobial potentials of active component isolated from Citrullus colocynthis fruits and structure-activity relationships of its analogues against foodborne bacteria.

BACKGROUND: Synthetic preservatives have been consistently used to maintain the quality of food products. However, the degree of danger to human health cannot be ignored. In this study, the antimicrobial activities of Citrullus colocynthis fruits and 4-methylquinoline analogues were investigated to develop natural preservatives against foodborne bacteria. RESULTS: Antimicrobial activities of the methanol extract and five fractions derived from C. colocynthis fruits were evaluated against five foodborne bacteria. The chloroform fraction possessed strong activities against five foodborne bacteria. 4-Methylquinoline was isolated by chromatographic analyses. To establish the structure-activity relationships, the antimicrobial activities of 4-methylquinoline analogues (2-hydroxyquinoline, 4-hydroxyquinoline, 6-hydroxyquinoline, 2-methylquinoline, 6-methyquinoline, 8-methylquinoline and 2-methyl-8-hydroxyquinoline) were tested against food-borne bacteria. When employing the agar diffusion method, 2-methyl-8-hydroxyquinoline was found to have potent activities against the five foodborne bacteria. In terms of minimum bactericidal concentration or minimum inhibitory concentration, 2-methyl-8-hydroxyquinoline had significantly higher antimicrobial activity against the five foodborne bacteria. CONCLUSION: Citrullus colocynthis fruits and 4-methylquinoline analogues could be useful for the development of eco-friendly food supplemental agents and pharmaceuticals.

Improvement in hematopoiesis after iron chelation therapy with deferasirox in patients with aplastic anemia.

Iron overload due to regular transfusions of packed red cells can cause multiple organ damage. Iron chelation therapy (ICT) is important in patients with aplastic anemia (AA) who require blood transfusions as supportive management. With the introduction of the oral iron chelator deferasirox, ICT has become more widely available and feasible. We studied 4 adult AA patients who had transfusion-induced iron overload and showed hematological improvement after ICT with oral deferasirox. Following deferasirox treatment, hemoglobin increased and serum ferritin levels decreased, and the patients subsequently became transfusion independent. Our experience raises the possibility of the potential benefit of ICT on hematopoiesis. Further long-term studies in larger patient cohorts are needed to clarify the effect of the restoration of hematopoiesis after iron chelation therapy.

Antiplatelet activities of newly synthesized derivatives of piperlongumine.

Piperlongumine, a pyridone alkaloid isolated from Piper longum L., exhibited a potential inhibitory effect on washed rabbit platelet aggregation induced by collagen, arachidonic acid (AA) and platelet activating factor (PAF), without any inhibitory effect on that induced by thrombin. Piperlongumine was used as a lead compound for the synthesis of new antiplatelet agents. Seven synthetic compounds were newly synthesized from 3,4,5-trimethoxycinnamic acid (TMCA). They were 1-piperidin-1-yl-3-(3,4,5-trimethoxy-phenyl)prop-2-en-1-one (1'), 1-morpholin-4-yl-3-(3,4,5-trimethoxyphenyl)prop-2-en-1-one (2'), 1-(3,5-dimethylpiperidin-1-yl)-3-(3,4,5-trimethoxyphenyl)prop-2-en-1-one (3'), 1-(2-methylpiperidin-1-yl)-3-(3,4,5-tri-methoxyphenyl)prop-2-en-1-one (4'), 1-(3-hydroxypiperidin-1-yl)-3-(3,4,5-trimethoxyphenyl)- prop-2-en-1-one (5'), 1-[3-(3,4,5-tri-methoxyphenyl) acryloyl]-piperidin-2-one (6') and ethyl 1-[3-(3,4,5-trimethoxyphenyl)-acryloyl]piperidine-4-carboxylate (7'). Among those seven synthetic derivatives, 1-(3,5-dimethylpiperidin-1-yl)-3-(3,4,5-trimethoxyphenyl)prop-2-en-1-one (3') had the most inhibitory effect on platelet aggregation induced by collagen, AA and PAF.

Antimalarial activity of anthothecol derived from Khaya anthotheca (Meliaceae).

Antimalarial activity of anthothecol, a limonoid of Khaya anthotheca (Meliaceae) against Plasmodium falciparum was tested using a [(3)H]-hypoxanthine and 48h culture assay in vitro. Anthotechol showed potent antimalarial activity against malaria parasites with IC(50) values of 1.4 and 0.17microM using two different assays. Also, gedunin had antimalarial activity with IC(50) values of 3.1 and 0.14microM. However, the citrus limonoids, limonin and obacunone did not show any antimalarial activity. The antimalarial activities were compared with the three currently used antimalarial medicines quinine, chloroquinine and artemisinin.

Inhibitory effects of Tabebuia impetiginosa inner bark extract on platelet aggregation and vascular smooth muscle cell proliferation through suppressions of arachidonic acid liberation and ERK1/2 MAPK activation.

The antiplatelet and antiproliferative activities of extract of Tabebuia impetiginosa inner bark (taheebo) were investigated using washed rabbit platelets and cultured rat aortic vascular smooth muscle cells (VSMCs) in vitro. n-Hexane, chloroform and ethyl acetate fractions showed marked and selective inhibition of platelet aggregation induced by collagen and arachidonic acid (AA) in a dose-dependent manner. These fractions, especially the chloroform fraction, also significantly suppressed AA liberation induced by collagen in [(3)H]AA-labeled rabbit platelets. The fractions, especially the chloroform fraction, potently inhibited cell proliferation and DNA synthesis induced by platelet derived growth factor (PDGF)-BB, and inhibited the levels of phosphorylated extracellular signal regulated kinase (ERK1/2) mitogen activated protein kinase (MAPK) stimulated by PDGF-BB, in the same concentration range that inhibits VSMC proliferation and DNA synthesis.

Antibacterial activity of Tabebuia impetiginosa Martius ex DC (Taheebo) against Helicobacter pylori.

The growth-inhibiting activity of Tabebuia impetiginosa Martius ex DC dried inner bark-derived constituents against Helicobacter pylori ATCC 43504 was examined using paper disc diffusion and minimum inhibitory concentration (MIC) bioassays. The activity of the isolated compounds was compared to that of the commercially available anti-Helicobacter pylori agents, amoxicillin, metronidazole, and tetracycline. The biologically active components of Tabebuia impetiginosa dried inner bark (taheebo) were characterized by spectroscopic analysis as 2-(hydroxymethyl)anthraquinone, anthraquinone-2-carboxylic acid, and 2-hydroxy-3-(3-methyl-2-butenyl)-1,4-naphthoquinone (lapachol). With the paper disc diffusion assay 2-(hydroxymethyl)anthraquinone exhibited strong activity against Helicobacter pylori ATCC 43504 at 0.01 mg/disc. Anthraquinone-2-carboxylic acid, lapachol and metronidazole were less effective, exhibiting moderate anti-Helicobacter pylori activity at 0.1 mg/disc. Amoxicillin and tetracycline were the most potent compounds tested, displaying very strong activity at 0.005 mg/disc. 2-(Hydroxymethyl)anthraquinone exhibited moderate activity at this dose. Tetracycline still had strong activity at 0.001 mg/disc while amoxicillin had little activity at this dose. In the MIC bioassay, 2-(hydroxymethyl)anthraquinone (2 microg/mL), anthraquinone-2-carboxylic acid (8 microg/mL), and lapachol (4 microg/mL) were more active than metronidazole (32 microg/mL) but less effective than amoxicillin (0.063 microg/mL) and tetracycline (0.5 microg/mL). The anti-Helicobacter pylori activity of seven 1,4-naphthoquinone derivatives (structurally related to lapachol), 1,4-naphthoquinone, 5,8-dihydroxy-1,4-naphthoquinone (naphthazarin), 2-methyl-1,4-naphthoquinone (menadione), 2-hydroxy-1,4-naphthoquinone (lawsone), 5-hydroxy-2-methyl-1,4-naphthoquinone (plumbagin), 5-hydroxy-1,4-naphthoquinone (juglone), and 2,3-dichloro-1,4-naphthoquinone (dichlone) was also evaluated using the paper disc assay. Menadione and plumbagin were the most potent compounds tested with the later still exhibiting very strong activity at 0.001 mg/disc. Menadione, juglone and tetracycline had strong activity at this low dose while the latter two compounds and amoxicillin had very strong activity at 0.005 mg/disc. Lawsone was unusual in that it had very strong activity at 0.1 and 0.05 mg/disc but weak activity at doses of 0.01 mg/disc and lower. Naphthazalin, lapachol and dichlone had similar activities while metronidazole had the lowest activity of all compounds tested. These results may be an indication of at least one of the pharmacological actions of taheebo. The Tabebuia impetiginosa dried inner bark-derived materials, particularly 2-(hydroxymethyl)anthraquinone, merit further study as potential Helicobacter pylori eradicating agents or lead compounds.