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Cannabidiol (CBD) has gained widespread popularity; however, its pharmacological and toxicological profiles in the context of human genetic diversity remain largely unexplored. Here, we investigated the variability in metabolism and toxicity of CBD-rich cannabis extract (CRCE) in genetically diverse mouse models: C57BL/6J, B6C3F1/J, and NZO/HlLtJ strains. Mice received a single dose of CRCE containing 57.9% CBD at dosages of 0, 246, 738, and 2460 mg/kg of CBD. At 24 h after treatment, no appreciable histomorphological changes were detected in the liver. Plasma bilirubin levels increased markedly in all strains at the highest CBD dose. Mice in all treatment groups displayed significant but distinct increases in ALT and AST levels. While B6C3F1/J and NZO/HlLtJ mice had negligible plasma CBD levels at 738 mg/kg, C57BL/6J mice exhibited levels exceeding 7000 ng/mL. At 2460 mg/kg, high CBD concentrations were found in B6C3F1/J and C57BL/6J mice, but markedly lower levels were seen in NZO/HlLtJ mice. Gene expression profiling showed significant increases in Cyp2b10 across all strains but varying responses in Cyp1a1 expression, indicating strain-specific CYP dysregulation. Genetically diverse mice exhibited differential pharmacological and toxicological responses to CRCE, suggesting a high potential for inter-individual variability in the pharmacology and toxicology of CBD in humans.
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Cannabidiol (CBD) is a major phytocannabinoid from Cannabis sativa. It is currently widely available and widely used in the USA, but despite its rapid progress to market, the pharmacology and toxicology of both CBD and cannabidiol-rich cannabis extracts (CRCE) remain largely unknown. The goals of this study were to investigate the potential of a novel human microphysiological system to emulate CRCE-induced hepatotoxicity and pharmacological properties demonstrated in animal models. For this purpose, C57BL6/J male mice were subjected to dosing with either 0, 61.5, 184.5, or 615 mg/kg of CRCE for 10 days. The liver-on-chip system, incorporating human primary hepatocytes, sinusoidal endothelial cells, as well as Kupffer and stellate cells was subjected to 0, 300, 1,200, or 4,400 ng/mL of CRCE (8 h exposure followed by 16 h washout) for 5 days. Administration of CRCE in mice resulted in nearly 4-fold elevations of plasma ALT at 615 mg/kg (p < 0.01) and a dose-dependent decrease in intrahepatic miR-122. Elevated levels of ALT, paralleled by decreased intrahepatic and increased effluent levels of miR-122, were also observed in the liver-on-chip, although these results were not statistically significant. Exposure to CRCE resulted in a robust and dose-dependent induction of key cytochrome P450 enzymes, namely Cyp1a2, Cyp2b6 (CYP2B10), Cyp2e1, and Cyp2c9 (CYP2C19) in both mouse livers and liver-on-chip. The results of this study demonstrate the congruence between the responses observed in mouse and human liver-on-chip experimental systems and provide evidence of the potential microphysiological systems hold for translating animal data into clinical practice.
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PURPOSE: Astronauts on missions beyond low Earth orbit will be exposed to galactic cosmic radiation, and there is concern about potential adverse cardiovascular effects. Most of the research to identify cardiovascular risk of space radiation has been performed in rodent models. To aid in the translation of research results to humans, the current study identified long-term effects of high-energy charged particle irradiation on cardiovascular function and structure in a larger non-rodent animal model. MATERIALS AND METHODS: At the age of 12 months, male New Zealand white rabbits were exposed to whole-body protons (250 MeV) or oxygen ions (16O, 600 MeV/n) at a dose of 0 or 0.5 Gy and were followed for 12 months after irradiation. Ultrasonography was used to measure in vivo cardiac function and blood flow parameters at 10- and 12-months post-irradiation. At 12 months after irradiation, blood cell counts and blood chemistry values were assessed, and cardiac tissue and aorta were collected for histological as well as molecular and biochemical analyses. Plasma was used for metabolomic analysis and to quantify common markers of cardiac injury. RESULTS: A small but significant decrease in the percentage of circulating lymphocytes and an increase in neutrophil percentage was seen 12 months after 0.5 Gy protons, while 16O exposure resulted in an increase in monocyte percentage. Markers of cardiac injury, cardiac troponin I (cTnI) and N-Terminal pro-B-type Natriuretic Peptide were modestly increased in the proton group, and cTnI was also increased after 16O. On the other hand, metabolomics on plasma at 12 months revealed no changes. Both types of irradiation demonstrated alterations in cardiac mitochondrial morphology and an increase in left ventricular protein levels of inflammatory cell marker CD68. However, changes in cardiac function were only mild. CONCLUSION: Low dose charged particle irradiation caused mild long-term changes in inflammatory markers, cardiac function, and structure in the rabbit heart, in line with previous studies in mouse and rat models.
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Radiación Cósmica , Protones , Humanos , Conejos , Masculino , Ratas , Ratones , Animales , Lactante , Oxígeno , Iones , Corazón/efectos de la radiación , Relación Dosis-Respuesta en la RadiaciónRESUMEN
PURPOSE: Nuclear weapons testing in the northern Marshall Islands between 1946 and 1958 resulted in ionizing radiation (IR) exposure of the thousands of Marshallese. Furthermore, numerous islands were contaminated by radioactive fallout. Significant increases in cancer and metabolic syndrome incidences have been reported among Marshallese, and potential for further increases looms due to the latency of radiation-induced health effects. The purpose of this study was to investigate the genetic and epigenetic effects of exposure to IR that could be associated with radiation-induced disease among the Northwest Arkansas (NWA) Marshallese. MATERIALS AND METHODS: We performed analysis of chromosomal aberrations and DNA methylation based on residential and exposure history of NWA Marshallese. RESULTS: Analysis of chromosomal aberrations demonstrated higher incidence of genetic rearrangements in women with self-reported history of radiation exposure (95% CI: 0.10, 1.22; p=.022). Further clustering of study participants based on their residential history demonstrated that participants who spent substantial amounts of time (≥6 months) in the northern atolls (thus, in the proximity of nuclear tests) before 1980 had more chromosomal aberrations than their peers who lived only in the southern atolls (95% CI: 0.08, -0.95; p=.021), and that this difference was driven by women. A relationship between the time spent in the northern atolls and increase in chromosomal aberrations was observed: 0.31 increase in chromosomal aberrations for every 10 years spent at northern atolls (95% CI: 0.06, 0.57; p=.020). Finally, significant inverse correlations between the chromosomal aberrations and the extent of DNA methylation of four LINE-1 elements L1PA2, L1PA16, L1PREC1, and L1P4B were identified. CONCLUSIONS: The results of this study provide first evidence of the presence of stable genetic and epigenetic rearrangements in peripheral lymphocytes of NWA Marshallese and warrant further studies to analyze the role of radiation exposure in health disparities experienced by this Pacific Island nation.
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Aberraciones Cromosómicas , Linfocitos , Femenino , Humanos , Arkansas , Análisis Citogenético , Epigénesis GenéticaRESUMEN
BACKGROUND AND PURPOSE: Identification of appropriate dietary strategies for prevention of weight and muscle loss in cancer patients is crucial for successful treatment and prolonged patient survival. High-protein oral nutritional supplements decrease mortality and improve indices of nutritional status in cancer patients; however, high-protein diets are often rich in methionine, and experimental evidence indicates that a methionine-supplemented diet (MSD) exacerbates gastrointestinal toxicity after total body irradiation. Here, we sought to investigate whether MSD can exacerbate gastrointestinal toxicity after local abdominal irradiation, an exposure regimen more relevant to clinical settings. MATERIALS AND METHODS: Male CBA/CaJ mice fed either a methionine-adequate diet or MSD (6.5 mg methionine/kg diet vs 19.5 mg/kg) received localized abdominal X-irradiation (220 kV, 13 mA) using the Small Animal Radiation Research Platform, and tissues were harvested 4, 7, and 10 days after irradiation. RESULTS: MSD exacerbated gastrointestinal toxicity after local abdominal irradiation with 12.5 Gy. This was evident as impaired nutrient absorption was paralleled by reduced body weight recovery. Mechanistically, significant shifts in the gut ecology, evident as decreased microbiome diversity, and substantially increased bacterial species that belong to the genus Bacteroides triggered proinflammatory responses. The latter were evident as increases in circulating neutrophils with corresponding decreases in lymphocytes and associated molecular alterations, exhibited as increases in mRNA levels of proinflammatory genes Icam1, Casp1, Cd14, and Myd88. Altered expression of the tight junction-related proteins Cldn2, Cldn5, and Cldn6 indicated a possible increase in intestinal permeability and bacterial translocation to the liver. CONCLUSIONS: We report that dietary supplementation with methionine exacerbates gastrointestinal syndrome in locally irradiated mice. This study demonstrates the important roles registered dieticians should play in clinical oncology and further underlines the necessity of preclinical and clinical investigations in the role of diet in the success of cancer therapy.
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Abdomen/efectos de la radiación , Suplementos Dietéticos/efectos adversos , Tracto Gastrointestinal/efectos de los fármacos , Tracto Gastrointestinal/efectos de la radiación , Metionina/efectos adversos , Animales , Peso Corporal/efectos de los fármacos , Peso Corporal/efectos de la radiación , Suplementos Dietéticos/análisis , Relación Dosis-Respuesta a Droga , Microbioma Gastrointestinal/efectos de los fármacos , Microbioma Gastrointestinal/efectos de la radiación , Tracto Gastrointestinal/metabolismo , Tracto Gastrointestinal/microbiología , Masculino , Ratones , ARN Mensajero/genética , Transcriptoma/efectos de los fármacos , Transcriptoma/efectos de la radiaciónRESUMEN
Cannabidiol (CBD) is a biologically active, non-psychotropic component of Cannabis sativa whose popularity has grown exponentially in recent years. Besides a wealth of potential health benefits, ingestion of CBD poses risks for a number of side effects, of which hepatotoxicity and CBD/herb-drug interactions are of particular concern. Here, we investigated the interaction potential between the cannabidiol-rich cannabis extract (CRCE) and methylsulfonylmethane (MSM), a popular dietary supplement, in the mouse model. For this purpose, 8-week-old male C57BL6/J mice received MSM-containing water (80 mg/100 mL) ad libitum for 17 days. During the last three days of treatment, mice received three doses of CRCE administered in sesame oil via oral gavage (123 mg/kg/day). Administration of MSM alone did not result in any evidence of liver toxicity and did not induce expression of mouse cytochrome P450 (CYP) enzymes. Administration of CRCE did produce significant (p < 0.05) increases in Cyp1a2, Cyp2b10, Cyp2c29, Cyp3a4, Cyp3a11, Cyp2c65, and Cyp2c66 messenger RNA, however, this effect was not amplified by MSM/CRCE co-treatment. Similarly, no evidence of liver toxicity was observed in MSM/CRCE dosed mice. In conclusion, short-term MSM/CRCE co-administration did not demonstrate any evidence of hepatotoxicity in the mouse model.
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Cannabidiol/toxicidad , Extractos Vegetales/toxicidad , Fosfatasa Alcalina/sangre , Animales , Cannabidiol/farmacocinética , Cannabis/química , Enfermedad Hepática Inducida por Sustancias y Drogas/sangre , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Sistema Enzimático del Citocromo P-450/metabolismo , Suplementos Dietéticos/toxicidad , Glutamina/análogos & derivados , Glutamina/metabolismo , Interacciones de Hierba-Droga , Masculino , Ratones Endogámicos C57BL , Extractos Vegetales/química , Extractos Vegetales/farmacocinética , Taurina/análogos & derivados , Taurina/metabolismo , Pruebas de ToxicidadRESUMEN
Cannabidiol (CBD) is the major non-psychotropic phytocannabinoid present in Cannabis sativa. In 2018, Congress designated certain C. sativa plant material as "hemp," thus removing it from the DEA's list of controlled substances. As a result, CBD-containing hemp extracts and other CBD products are now widely available and heavily marketed, yet their FDA regulatory status is still hotly debated. The goal of this study was to investigate the effects of a cannabidiol-rich cannabis extract (CRCE) on the gut microbiome and associated histomorphological and molecular changes in the mouse gut mucosa. Male C57BL6/J mice were gavaged with either 0, 61.5, 184.5, or 615 mg/kg/bw of CRCE in sesame oil for 2 weeks (Mon-Fri). Substantial CRCE-induced increases in the relative abundance of A. muciniphila, a bacterial species currently accepted as probiotic, was observed in fecal samples at all doses. This was paralleled by decreases in the relative abundance of other gut bacterial species. Coincident with the observed changes in gut ecology were multiple pro-inflammatory responses, including increased expression of cytokines and chemokines-Il1ß, Cxcl1, and Cxcl2 in the colon tissue. Furthermore, dramatic increases in the relative abundance of A. muciniphila significantly decreased expression of Muc2-a gene intimately associated with gut integrity. Taken together, these findings raise concerns about the safety of long-term CBD usage and underline the need for additional well-designed studies into its tolerability and efficacy.
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Cannabidiol/efectos adversos , Cannabis , Colitis/inducido químicamente , Microbioma Gastrointestinal/efectos de los fármacos , Extractos Vegetales/efectos adversos , Akkermansia/efectos de los fármacos , Animales , Quimiocinas/efectos de los fármacos , Colon/metabolismo , Citocinas/efectos de los fármacos , Modelos Animales de Enfermedad , Mucosa Intestinal/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Mucina 2/metabolismoRESUMEN
Methionine is an essential amino acid needed for a variety of processes in living organisms. Ionizing radiation depletes tissue methionine concentrations and leads to the loss of DNA methylation and decreased synthesis of glutathione. In this study, we aimed to investigate the effects of methionine dietary supplementation in CBA/CaJ mice after exposure to doses ranging from 3 to 8.5 Gy of 137Cs of total body irradiation. We report that mice fed a methionine-supplemented diet (MSD; 19.5 vs. 6.5 mg/kg in a methionine-adequate diet, MAD) developed acute radiation toxicity at doses as low as 3 Gy. Partial body irradiation performed with hindlimb shielding resulted in a 50% mortality rate in MSD-fed mice exposed to 8.5 Gy, suggesting prevalence of radiation-induced gastrointestinal syndrome in the development of acute radiation toxicity. Analysis of the intestinal microbiome demonstrated shifts in the gut ecology, observed along with the development of leaky gut syndrome and bacterial translocation into the liver. Normal gut physiology impairment was facilitated by alterations in the one-carbon metabolism pathway and was exhibited as decreases in circulating citrulline levels mirrored by decreased intestinal mucosal surface area and the number of surviving crypts. In conclusion, we demonstrate that a relevant excess of methionine dietary intake exacerbates the detrimental effects of exposure to ionizing radiation in the small intestine.NEW & NOTEWORTHY Methionine supplementation, instead of an anticipated health-promoting effect, sensitizes mice to gastrointestinal radiation syndrome. Mechanistically, excess of methionine negatively affects intestinal ecology, leading to a cascade of physiological, biochemical, and molecular alterations that impair normal gut response to a clinically relevant genotoxic stressor. These findings speak toward increasing the role of registered dietitians during cancer therapy and the necessity of a solid scientific background behind the sales of dietary supplements and claims regarding their benefits.
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Síndrome de Radiación Aguda/etiología , Suplementos Dietéticos/toxicidad , Intestino Delgado/efectos de los fármacos , Metionina/toxicidad , Traumatismos Experimentales por Radiación/etiología , Síndrome de Radiación Aguda/metabolismo , Síndrome de Radiación Aguda/microbiología , Síndrome de Radiación Aguda/patología , Animales , Metilación de ADN/efectos de los fármacos , Disbiosis , Metabolismo Energético/efectos de los fármacos , Microbioma Gastrointestinal/efectos de los fármacos , Intestino Delgado/metabolismo , Intestino Delgado/microbiología , Intestino Delgado/patología , Masculino , Ratones Endogámicos C57BL , Ratones Endogámicos CBA , Dosis de Radiación , Traumatismos Experimentales por Radiación/metabolismo , Traumatismos Experimentales por Radiación/microbiología , Traumatismos Experimentales por Radiación/patología , Factores de Riesgo , Irradiación Corporal TotalRESUMEN
Purpose: Growing rates of metabolic syndrome and associated obesity warrant the development of appropriate animal models for better understanding of how those conditions may affect sensitivity to IR exposure.Materials and methods: We subjected male NZO/HlLtJ mice, a strain prone to spontaneous obesity and diabetes, to 0, 5.5, 6.37, 7.4 or 8.5 Gy (137Cs) of total body irradiation (TBI). Mice were monitored for 30 days, after which proximal jejunum and colon tissues were collected for further histological and molecular analysis.Results: Obese NZO/HlLtJ male mice are characterized by their lower sensitivity to IR at doses of 6.37 Gy and under, compared to other strains. Further escalation of the dose, however, results in a steep survival curve, reaching LD100/30 values at a dose of 8.5 Gy. Alterations in the expression of various tight junction-related proteins coupled with activation of inflammatory responses and cell death were the main contributors to the gastrointestinal syndrome.Conclusions: We demonstrate that metabolic syndrome with exhibited hyperglycemia but without alterations to the microvasculature is not a pre-requisite of the increased sensitivity to TBI at high doses. Our studies indicate the potential of NZO/HlLtJ mice for the studies on the role of metabolic syndrome in acute radiation toxicity.
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Síndrome Metabólico/etiología , Traumatismos por Radiación/etiología , Animales , Glucemia/metabolismo , Modelos Animales de Enfermedad , Masculino , Síndrome Metabólico/sangre , Síndrome Metabólico/complicaciones , Síndrome Metabólico/patología , Ratones , Obesidad/complicaciones , Traumatismos por Radiación/sangre , Traumatismos por Radiación/complicaciones , Traumatismos por Radiación/patología , Análisis de Supervivencia , Uniones Estrechas/efectos de la radiaciónRESUMEN
Cardiovascular disease constitutes an important threat to humans after space missions beyond the Earth's magnetosphere. Epigenetic alterations have an important role in the etiology and pathogenesis of cardiovascular disease. Previous research in animal models has shown that protons and 56Fe ions cause long-term changes in DNA methylation and expression of repetitive elements in the heart. However, astronauts will be exposed to a variety of ions, including the smaller fragmented products of heavy ions after they interact with the walls of the space craft. Here, we investigated the effects of 16O on the cardiac methylome and one-carbon metabolism in male C57BL/6â¯J mice. Left ventricles were examined 14 and 90 days after exposure to space-relevant doses of 0.1, 0.25, or 1â¯Gy of 16O (600 MeV/n). At 14 days, the two higher radiation doses elicited global DNA hypomethylation in the 5'-UTR of Long Interspersed Nuclear Elements 1 (LINE-1) compared to unirradiated, sham-treated mice, whereas specific LINE-1 elements exhibited hypermethylation at day 90. The pericentromeric major satellites were affected both at the DNA methylation and expression levels at the lowest radiation dose. DNA methylation was elevated, particularly after 90 days, while expression showed first a decrease followed by an increase in transcript abundance. Metabolomics analysis revealed that metabolites involved in homocysteine remethylation, central to DNA methylation, were unaffected by radiation, but the transsulfuration pathway was impacted after 90 days, with a large increase in cystathione levels at the lowest dose. In summary, we observed dynamic changes in the cardiac epigenome and metabolome three months after exposure to a single low dose of oxygen ions.
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Metilación de ADN/efectos de la radiación , Corazón/efectos de la radiación , Miocardio/metabolismo , Oxígeno/química , Radiación Ionizante , Vuelo Espacial , Animales , Carbono/metabolismo , Centrómero , ADN Satélite , Expresión Génica/efectos de la radiación , Iones/química , Masculino , Redes y Vías Metabólicas , Metionina/metabolismo , Ratones , Ratones Endogámicos C57BL , Secuencias Repetitivas de Ácidos NucleicosRESUMEN
The goal of this study was to investigate the potential for a cannabidiol-rich cannabis extract (CRCE) to interact with the most common over-the-counter drug and the major known cause of drug-induced liver injury-acetaminophen (APAP)-in aged female CD-1 mice. Gavaging mice with 116 mg/kg of cannabidiol (CBD) [mouse equivalent dose (MED) of 10 mg/kg of CBD] in CRCE delivered with sesame oil for three consecutive days followed by intraperitoneally (i.p.) acetaminophen (APAP) administration (400 mg/kg) on day 4 resulted in overt toxicity with 37.5% mortality. No mortality was observed in mice treated with 290 mg/kg of CBD+APAP (MED of 25 mg/kg of CBD) or APAP alone. Following CRCE/APAP co-administration, microscopic examination revealed a sinusoidal obstruction syndrome-like liver injury-the severity of which correlated with the degree of alterations in physiological and clinical biochemistry end points. Mechanistically, glutathione depletion and oxidative stress were observed between the APAP-only and co-administration groups, but co-administration resulted in much greater activation of c-Jun N-terminal kinase (JNK). Strikingly, these effects were not observed in mice gavaged with 290 mg/kg CBD in CRCE followed by APAP administration. These findings highlight the potential for CBD/drug interactions, and reveal an interesting paradoxical effect of CBD/APAP-induced hepatotoxicity.
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Acetaminofén/efectos adversos , Cannabidiol/efectos adversos , Enfermedad Veno-Oclusiva Hepática/diagnóstico , Enfermedad Veno-Oclusiva Hepática/etiología , Animales , Biomarcadores , Cannabidiol/química , Cannabis/química , Enfermedad Hepática Inducida por Sustancias y Drogas/diagnóstico , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Femenino , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Ratones , Ratones Endogámicos , Fitoquímicos/efectos adversos , Fitoquímicos/química , Extractos Vegetales/efectos adversosRESUMEN
The goal of this study was to investigate Cannabidiol (CBD) hepatotoxicity in 8-week-old male B6C3F1 mice. Animals were gavaged with either 0, 246, 738, or 2460 mg/kg of CBD (acute toxicity, 24 h) or with daily doses of 0, 61.5, 184.5, or 615 mg/kg for 10 days (sub-acute toxicity). These doses were the allometrically scaled mouse equivalent doses (MED) of the maximum recommended human maintenance dose of CBD in EPIDIOLEX® (20 mg/kg). In the acute study, significant increases in liver-to-body weight (LBW) ratios, plasma ALT, AST, and total bilirubin were observed for the 2460 mg/kg dose. In the sub-acute study, 75% of mice gavaged with 615 mg/kg developed a moribund condition between days three and four. As in the acute phase, 615 mg/kg CBD increased LBW ratios, ALT, AST, and total bilirubin. Hepatotoxicity gene expression arrays revealed that CBD differentially regulated more than 50 genes, many of which were linked to oxidative stress responses, lipid metabolism pathways and drug metabolizing enzymes. In conclusion, CBD exhibited clear signs of hepatotoxicity, possibly of a cholestatic nature. The involvement of numerous pathways associated with lipid and xenobiotic metabolism raises serious concerns about potential drug interactions as well as the safety of CBD.
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Cannabidiol/química , Cannabidiol/farmacología , Cannabis/química , Hepatocitos/efectos de los fármacos , Extractos Vegetales/química , Extractos Vegetales/farmacología , Animales , Biomarcadores , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Modelos Animales de Enfermedad , Perfilación de la Expresión Génica , Hepatocitos/metabolismo , Pruebas de Función Hepática , Ratones , TranscriptomaRESUMEN
The main purpose of this study was to investigate the hepatotoxic potential and effects on the gut microbiome of decaffeinated green tea extract (dGTE) in lean B6C3F1 mice. Gavaging dGTE over a range of 1X-10X mouse equivalent doses (MED) for up to two weeks did not elicit significant histomorphological, physiological, biochemical or molecular alterations in mouse livers. At the same time, administration of dGTE at MED comparable to those consumed by humans resulted in significant modulation of gut microflora, with increases in Akkermansia sp. being most pronounced. Results of this study demonstrate that administration of relevant-to-human-consumption MED of dGTE to non-fasting mice does not lead to hepatotoxicity. Furthermore, dGTE administered to lean mice, caused changes in gut microflora comparable to those observed in obese mice. This study provides further insight into the previously reported weight management properties of dGTE; however, future studies are needed to fully evaluate and understand this effect.
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Fármacos Antiobesidad/farmacología , Bacterias/efectos de los fármacos , Microbioma Gastrointestinal/efectos de los fármacos , Extractos Vegetales/farmacología , Té/química , Animales , Fármacos Antiobesidad/aislamiento & purificación , Fármacos Antiobesidad/toxicidad , Bacterias/crecimiento & desarrollo , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Relación Dosis-Respuesta a Droga , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Masculino , Ratones , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/toxicidad , Medición de Riesgo , DelgadezRESUMEN
Herbal dietary supplement (HDS)-induced hepato- and cardiotoxicity is an emerging clinical problem. In this study, we investigated the liver and heart toxicity of HDS OxyELITE-PRO™ New Formula (OEP-NF), a dietary supplement marketed for weight loss and performance enhancement that was recently withdrawn from the market. Using a novel NZO/HlLtJ obese mouse model, we demonstrated that administration of clinically relevant mouse equivalent doses (MED) of OEP-NF produced cardio- and hepatotoxic risks following both short- and long-term administration schedules. Specifically, gavaging female NZO/HlLtJ with up to 2X MED of OEP-NF resulted in 40% mortality within two weeks. Feeding mice with either 1X or 3X MED of OEP-NF for eight weeks, while not exhibiting significant effects on body weights, significantly altered hepatic gene expression, increased the number of apoptotic and mast cells in the heart and affected cardiac function. The degree of toxicity in NZO/HlLtJ mice was higher than that observed previously in non-obese CD-1 and B6C3F1 strains, suggesting that an overweight/obese condition can sensitize mice to OEP-NF. Adverse health effects linked to OEP-NF, together with a number of other hepato- and cardiotoxicity cases associated with HDS ingestion, argue strongly for introduction of quality standards and pre-marketing safety assessments for multi-ingredient HDS.
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Cardiotoxicidad/etiología , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Suplementos Dietéticos/toxicidad , Modelos Animales de Enfermedad , Obesidad/fisiopatología , Fitoquímicos/toxicidad , Administración Oral , Animales , Cromatografía Líquida de Alta Presión/métodos , Suplementos Dietéticos/análisis , Ecocardiografía , Conducta Alimentaria , Femenino , Perfilación de la Expresión Génica , Hígado/efectos de los fármacos , Hígado/metabolismo , Ratones , Miocardio/metabolismo , Obesidad/genética , Obesidad/metabolismoRESUMEN
Methionine dependency describes the characteristic rapid in vitro death of most tumor cells in the absence of methionine. Combining chemotherapy with dietary methionine deprivation [methionine-deficient diet (MDD)] at tolerable levels has vast potential in tumor treatment; however, it is limited by MDD-induced toxicity during extended deprivation. Recent advances in imaging and irradiation delivery have created the field of stereotactic body radiotherapy (SBRT), where fewer large-dose fractions delivered in less time result in increased local-tumor control, which could be maximally synergistic with an MDD short course. Identification of the lowest effective methionine dietary intake not associated with toxicity will further enhance the cancer therapy potential. In this study, we investigated the effects of MDD and methionine-restricted diet (MRD) in primary and metastatic melanoma models in combination with radiotherapy (RT). In vitro, MDD dose-dependently sensitized mouse and human melanoma cell lines to RT. In vivo in mice, MDD substantially potentiated the effects of RT by a significant delay in tumor growth, in comparison with administering MDD or RT alone. The antitumor effects of an MDD/RT approach were due to effects on one-carbon metabolism, resulting in impaired methionine biotransformation via downregulation of Mat2a, which encodes methionine adenosyltransferase 2A. Furthermore, and probably most importantly, MDD and MRD substantially diminished metastatic potential; the antitumor MRD effects were not associated with toxicity to normal tissue. Our findings suggest that modulation of methionine intake holds substantial promise for use with short-course SBRT for cancer treatment.
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Antineoplásicos/farmacología , Melanoma/dietoterapia , Melanoma/patología , Metionina Adenosiltransferasa/biosíntesis , Metionina/farmacología , Animales , Antineoplásicos/administración & dosificación , Línea Celular Tumoral , Humanos , Masculino , Metionina/administración & dosificación , Metionina/metabolismo , Ratones , Ratones Endogámicos C57BL , Metástasis de la Neoplasia/patologíaRESUMEN
BACKGROUND: Methionine, a central molecule in one-carbon metabolism, is an essential amino acid required for normal growth and development. Despite its importance to biological systems, methionine is toxic when administered at supra-physiological levels. The aim of this study was to investigate the effects of short-term methionine dietary modulation on the proximal jejunum, the section of the gut specifically responsible for amino acid absorption, in a mouse model. Eight-week-old CBA/J male mice were fed methionine-adequate (MAD; 6.5 g/kg) or methionine-supplemented (MSD; 19.5 g/kg) diets for 3.5 or 6 days (average food intake 100 g/kg body weight). The study design was developed in order to address the short-term effects of the methionine supplementation that corresponds to methionine dietary intake in Western populations. Biochemical indices in the blood as well as metabolic, epigenetic, transcriptomic, metagenomic, and histomorphological parameters in the gut were evaluated. RESULTS: By day 6, feeding mice with MSD (protein intake <10% different from MAD) resulted in increased plasma (2.3-fold; p < 0.054), but decreased proximal jejunum methionine concentrations (2.2-fold; p < 0.05) independently of the expression of neutral amino acid transporters. MSD has also caused small bowel bacteria colonization, increased the abundance of pathogenic bacterial species Burkholderiales and decreased the gene expression of the intestinal transmembrane proteins-Cldn8 (0.18-fold, p < 0.05), Cldn9 (0.24-fold, p < 0.01) and Cldn10 (0.05-fold, p < 0.05). Feeding MSD led to substantial histomorphological alterations in the proximal jejunum exhibited as a trend towards decreased plasma citrulline concentrations (1.8-fold, p < 0.07), as well as loss of crypt depth (by 28%, p < 0.05) and mucosal surface (by 20%, p < 0.001). CONCLUSIONS: Together, these changes indicate that short-term feeding of MSD substantially alters the normal gut physiology. These effects may contribute to the pathogenesis of intestinal inflammatory diseases and/or sensitize the gut to exposure to other stressors.
RESUMEN
Herbal dietary supplements have gained wide acceptance as alternatives to conventional therapeutic agents despite concerns regarding their efficacy and safety. In 2013, a spate of severe liver injuries across the United States was linked to the dietary supplement OxyELITE Pro-New Formula (OEP-NF), a multi-ingredient product marketed for weight loss and exercise performance enhancement. The principal goal of this study was to assess the hepatotoxic potential of OEP-NF in outbred and inbred mouse models. In an acute toxicity study, significant mortality was observed after administering 10X and 3X mouse-equivalent doses (MED) of OEP-NF, respectively. Increases in liver/body weight ratio, ALT and AST were observed in female B6C3F1 mice after gavaging 2X and 1.5X MED of OEP-NF. Similar findings were observed in a 90-day feeding study. These alterations were paralleled by altered expression of gene- and microRNA-signatures of hepatotoxicity, including Cd36, Nqo1, Aldoa, Txnrd1, Scd1 and Ccng1, as well as miR-192, miR-193a and miR-125b and were most pronounced in female B6C3F1 mice. Body weight loss, observed at week 1, was followed by weight gain throughout the feeding studies. These findings bolster safety and efficacy concerns for OEP-NF, and argue strongly for implementation of pre-market toxicity studies within the dietary supplement industry.
Asunto(s)
Suplementos Dietéticos/toxicidad , Animales , Animales no Consanguíneos , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Enfermedad Hepática Inducida por Sustancias y Drogas/genética , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/fisiopatología , Suplementos Dietéticos/análisis , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos , Femenino , Humanos , Hígado/efectos de los fármacos , Hígado/crecimiento & desarrollo , Masculino , Ratones , Ratones Endogámicos , MicroARNs/genética , MicroARNs/metabolismo , Tamaño de los Órganos , Pruebas de ToxicidadRESUMEN
DNA methylation is a key epigenetic mechanism, needed for proper control over the expression of genetic information and silencing of repetitive elements. Exposure to ionizing radiation, aside from its strong genotoxic potential, may also affect the methylation of DNA, within the repetitive elements, in particular. In this study, we exposed C57BL/6J male mice to low absorbed mean doses of two types of space radiation-proton (0.1 Gy, 150 MeV, dose rate 0.53 ± 0.08 Gy/min), and heavy iron ions ((56)Fe) (0.5 Gy, 600 MeV/n, dose rate 0.38 ± 0.06 Gy/min). Radiation-induced changes in cardiac DNA methylation associated with repetitive elements were detected. Specifically, modest hypomethylation of retrotransposon LINE-1 was observed at day 7 after irradiation with either protons or (56)Fe. This was followed by LINE-1, and other retrotransposons, ERV2 and SINE B1, as well as major satellite DNA hypermethylation at day 90 after irradiation with (56)Fe. These changes in DNA methylation were accompanied by alterations in the expression of DNA methylation machinery and affected the one-carbon metabolism pathway. Furthermore, loss of transposable elements expression was detected in the cardiac tissue at the 90-day time-point, paralleled by substantial accumulation of mRNA transcripts, associated with major satellites. Given that the one-carbon metabolism pathway can be modulated by dietary modifications, these findings suggest a potential strategy for the mitigation and, possibly, prevention of the negative effects exerted by ionizing radiation on the cardiovascular system. Additionally, we show that the methylation status and expression of repetitive elements may serve as early biomarkers of exposure to space radiation.
Asunto(s)
Metilación de ADN/efectos de la radiación , Corazón/efectos de la radiación , Traumatismos Experimentales por Radiación/genética , Animales , Daño del ADN , Epigénesis Genética , Cardiopatías/genética , Elementos de Nucleótido Esparcido Largo , Masculino , Metionina/metabolismo , Ratones Endogámicos C57BL , Análisis de Secuencia de ADNRESUMEN
The difficulty in long-term expansion of mesenchymal stem cells (MSCs) using standard culture systems without the loss of their stem cell properties suggests that a critical feature of their microenvironment necessary for retention of stem cell properties is absent in these culture systems. We report here the reconstitution of a native extracellular matrix (ECM) made by human marrow cells ex vivo, which consists of at least collagen types I and III, fibronectin, small leucine-rich proteoglycans such as biglycan and decorin, and major components of basement membrane such as the large molecular weight proteoglycan perlecan and laminin. Expansion of human MSCs on this ECM strongly promoted their proliferation, retained their stem cell properties with a low level of reactive oxygen species (ROS), and substantially increased their response to BMP-2. The quality of the expanded cells following each passage was further tested by an in vivo transplantation assay. The results showed that MSCs expanded on the ECM for multiple passages still retained the same capacity for skeletogenesis. In contrast, the bone formation capacity of cells expanded on plastic was dramatically diminished after 6-7 passages. These findings suggest that the marrow stromal cell-derived ECM is a promising matrix for expanding largescale highly functional MSCs for eventualuse in stem cell-based therapy. Moreover, this system should also be invaluable for establishment of a unique tissue-specific ECM, which will facilitate control of the fate of MSCs for therapeutic applications.