RESUMEN
Celastrol is an anti-inflammatory natural triterpenoid, isolated from the herb Tripterygium wilfordii or thunder god vine. Here, we define mechanisms mediating anti-inflammatory activity of celastrol and demonstrate efficacy of a dietary celastrol supplement for chemoprevention of inflammation-driven carcinogenesis in mice. Dietary celastrol (31.25 ppm in rodent diet from 8 weeks to 25 weeks of age) is well tolerated and protects against LPS-induced acute inflammation in C57BL/6 mice, potently suppressing LPS-induction of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, Interleukin (IL)-6 and IL-1ß. To test whether dietary celastrol suppresses inflammation-driven colorectal cancer (CRC), we employed a unique model of spontaneous, inflammation-driven CRC in mice harboring a germ line deletion of the p27Kip1 gene and a T cell-specific deletion of Smad4 gene (Smad4co/co;Lck-crep27Kip1-/-or DKO), which develop severe intestinal inflammation and carcinogenesis as early as 3 months of age. Exposure of DKO mice to daily dietary celastrol (12.5 ppm in diet) from 6 weeks of age significantly suppressed development of colitis-associated CRC (CAC). Celastrol chemoprevention of CAC in this new model of intestinal neoplasia was associated with significant suppression of iNOS at 4 months of age, and iNOS, COX-2 and NFκB at 6 months of age, with significant reduction in inflammatory cytokines, IL-6 and IL-1ß. Chemoprevetion of CAC by dietary celastrol was further confirmed in the model of azoxymethane (AOM) plus dextran sodium sulfate (DSS)-induced carcinogenesis in C57BL/6 mice. These data suggest the potential for celastrol as a safe and effective dietary supplement in the chemoprevention of CAC in humans.
Asunto(s)
Antiinflamatorios/farmacología , Carcinogénesis/efectos de los fármacos , Neoplasias Colorrectales/patología , Suplementos Dietéticos , Triterpenos/farmacología , Animales , Carcinógenos/toxicidad , Colitis/complicaciones , Neoplasias Colorrectales/etiología , Masculino , Ratones , Ratones Endogámicos C57BL , Triterpenos PentacíclicosRESUMEN
The thermal annealing behaviour of an electrolyte-triggered calixarene hydrogelator is found to depend strongly on the specific metal chloride used. While the lithium chloride gel showed typical gel-sol transitions as a function of temperature, the magnesium chloride gel was found to repeatedly strengthen with heat-cool cycles. Structural investigations using small-angle neutron scattering, and scanning probe microscopy, suggest that the annealing behaviour is associated with a change in morphology of the fibrous structures supporting the gel. On prolonged standing at room temperature, the magnesium chloride gel underwent a gel-crystal transition, with the collapsing gel accompanied by the deposition of crystals of a magnesium complex of the proline-functionalised calix[4]arene gelator.
RESUMEN
Bryonolic acid (BA) is a triterpenoid found in the Cucurbitaceae family of plants. Our interests in the immunomodulatory effects of this class of natural products led us to discover that BA induces a marked increase in the expression of a phase 2 response enzyme, heme oxygenase 1 (HO-1), in a dose-dependent manner. This phenotype has translational implications in malarial disease progression, and consequently we developed a large-scale isolation method for BA that will enable future in vitro and in vivo analyses. We have determined ideal growth conditions and time scale for maximizing BA content in the roots of Cucurbita pepo and analyzed BA production by HPLC. Large-scale extraction yielded 1.34% BA based on dry weight, allowing for the isolation of BA on a multigram scale.
Asunto(s)
Cucurbitaceae/crecimiento & desarrollo , Hemo-Oxigenasa 1/biosíntesis , Factores Inmunológicos , Macrófagos/efectos de los fármacos , Triterpenos/farmacología , Animales , Cromatografía Líquida de Alta Presión , Cucurbitaceae/química , Cucurbitaceae/genética , Relación Dosis-Respuesta a Droga , Germinación/fisiología , Hemo-Oxigenasa 1/genética , Hemo-Oxigenasa 1/metabolismo , Factores Inmunológicos/análisis , Factores Inmunológicos/química , Factores Inmunológicos/aislamiento & purificación , Factores Inmunológicos/farmacología , Macrófagos/metabolismo , Ratones , Estructura Molecular , Raíces de Plantas/química , Triterpenos/análisis , Triterpenos/química , Triterpenos/aislamiento & purificaciónRESUMEN
Narcolepsy is a neurological disorder of the sleep-wake cycle characterized by excessive daytime sleepiness (EDS), cataplexy, nighttime sleep disturbances, and REM-sleep-related phenomena (sleep paralysis, hallucinations) that intrude into wakefulness. Dysfunction of the hypocretin/orexin system has been implicated as the underlying cause of narcolepsy with cataplexy. In most people with narcolepsy, symptom onset occurs between the ages of 10 and 35 years, but because the disorder is underrecognized and testing is complex, delays in diagnosis and treatment are common. Narcolepsy is treated with a combination of lifestyle modifications and medications that promote wakefulness and suppress cataplexy. Treatments are often effective in improving daytime functioning for individuals with narcolepsy, but side effects and/or lack of efficacy can result in suboptimal management of symptoms and, in many cases, significant residual impairment. Additionally, the psychosocial ramifications of narcolepsy are often neglected. Recently two new pharmacologic treatment options, solriamfetol and pitolisant, have been approved for adults, and the indication for sodium oxybate in narcolepsy has been expanded to include children. In recent years, there has been an uptick in patient-centered research, and promising new diagnostic and therapeutic options are in development. This paper summarizes current and prospective pharmacological therapies for treating both EDS and cataplexy, discusses concerns specific to children and reproductive-age women with narcolepsy, and reviews the negative impact of health-related stigma and efforts to address narcolepsy stigma.
RESUMEN
The cyclin-dependent kinase inhibitor p27Kip1 is a tumor suppressor whose intrinsic activity in cancer cells correlates with tumor aggressiveness, invasiveness, and impaired tumor cell differentiation. Here we explore whether p27Kip1 indirectly influences tumor progression by restricting expansion and survival of effector memory T cell (TEM) populations in a preclinical model of spontaneous colitis-associated colorectal cancer (CAC). We show mRNA and protein expression of p27Kip1 to be significantly decreased in the colons of mice with a T cell-restricted deletion of the TGF-ß intermediate, SMAD4 (Smad4TKO). Loss of p27Kip1 expression in T cells correlates with the onset of spontaneous CAC in Smad4TKO mice by 8 months of age. This phenotype is greatly accelerated by the introduction of a germline deletion of CDKN1b (the gene encoding p27Kip1) in Smad4TKO mice (Smad4TKO/p27Kip1-/-, DKO). DKO mice display colon carcinoma by 3 months of age and increased mortality compared to Smad4TKO. Importantly, the phenotype in DKO mice is associated with a significant increase in the frequency of effector CD4 T cells expressing abundant IFN-γ and with a concomitant decrease in Foxp3+ regulatory T cells, both in the intestinal mucosa and in the periphery. In addition, induction of inflammatory mediators (IFN-γ, TNF-γ, IL-6, IL-1ß, iNOS) and activation of Stat1, Stat3, and IκB is also observed in the colon as early as 1-2 months of age. Our data suggest that genomic alterations known to influence p27Kip1 abundance in gastrointestinal cancers may indirectly promote epithelial malignancy by augmenting the production of inflammatory mediators from a spontaneously expanding pool of TEM cells.
Asunto(s)
Neoplasias Asociadas a Colitis , Memoria Inmunológica , Animales , Linfocitos T CD4-Positivos , Linaje de la Célula , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/genética , RatonesRESUMEN
OBJECTIVE: To determine GHB levels in breast milk of women taking sodium oxybate (Xyrem) for treatment of narcolepsy and cataplexy. METHODS: Two women with narcolepsy and cataplexy treated with sodium oxybate before pregnancy collected breast milk for analysis of GHB concentration after resuming sodium oxybate postpartum. One woman collected samples across two consecutive nights (doses: 3.0 gm and 4.5 gm twice per night) five months after delivering her first child; the other collected samples on three separate days (doses: 2.25 gm and 3.0 gm twice per night) nine months after the births of her first two children. GHB concentration was determined by gas chromatography/mass spectrometry. RESULTS: Milk GHB levels before sodium oxybate ranged from 5.81 to 7.60 µM. Levels were 2-4 times higher four hours after the first sodium oxybate dose (10.44-23.58 µM) and 3-5 times higher four hours after the second dose (ie, eight hours after first dose; 14.60-34.01 µM). GHB levels returned to endogenous levels 6-10 h following the second dose, however variability was observed between patients and pregnancies. Higher breast milk GHB levels were observed with higher doses for both patients. CONCLUSIONS: Sodium oxybate is transmitted to breast milk. Despite its short half-life, GHB concentrations remained two-to-five times higher than endogenous levels four hours after both nighttime doses. To avoid excess GHB exposure, breastfeeding mothers who take sodium oxybate should consider expressing and discarding their morning milk. Future work should examine milk GHB levels after chronic sodium oxybate and determine whether levels change as milk composition changes across the postpartum period.
Asunto(s)
Leche Humana/efectos de los fármacos , Narcolepsia/tratamiento farmacológico , Narcolepsia/metabolismo , Oxibato de Sodio/farmacocinética , Promotores de la Vigilia/farmacocinética , Adulto , Femenino , Cromatografía de Gases y Espectrometría de Masas , Humanos , Leche Humana/química , Oxibato de Sodio/uso terapéutico , Factores de Tiempo , Promotores de la Vigilia/uso terapéuticoRESUMEN
The assembly and disassembly of supramolecular gel fibres are observed in situ using variable temperature scanning probe microscopy. The results show that fibre formation can be monitored at high resolution at a surface, and the final fibre morphologies are broadly consistent with those found by ex situ analysis of the bulk gel. The impact of a gelation inhibitor upon the fibre morphology is successfully investigated, providing direct evidence for the mechanism of inhibition as a function of additive concentration.