Characterization of Crocetin Isomers in Serum Samples via UHPLC-DAD-MS/MS and NMR after Saffron Extract (Safr'Inside™) Consumption.

The therapeutic effects of saffron have been reported and described in relation to its major derivatives. Among them, in terms of saffron's properties, crocin and crocetin absorption and bioavailability have been the most studied. Nevertheless, the metabolism of these major compounds of saffron has not yet been entirely elucidated. Current data indicate that the phase 2 metabolism of crocetins go through conjugation reactions. Crocetins could also be present in isomeric forms such as other carotenoids. Nonetheless, there are still shadow areas in regard to the measurements of the different circulating forms of crocetins after oral saffron extract administration (Safr'Inside™). In using various approaches, we propose the identification of a new cis isomeric form of crocetin, the 6-cis-crocetin. This compound was found in human serum samples after an oral administration of saffron extract. The 6-cis-crocetin represents 19% of the total crocetin measured after 45 min of consumption. These data mark, for the first time, the presence of a cis isomeric form of crocetin in human serum samples. Moreover, this study led to the development of an analytical method that is able to identify and quantify both isomeric forms (trans and cis).

Reduced Production of Pro-Inflammatory and Pro-Catabolic Factors by Human Serum Metabolites Derived from a Patented Saffron Extract Intake.

Safe and anti-inflammatory plant-based natural products present an increasing focus in the treatment of chronic inflammatory diseases such as osteoarthritis or inflammatory bowel diseases. Among them, saffron, a spice derived from the stigma of Crocus sativus, could have anti-inflammatory properties and would be therefore a promising therapeutic agent for the treatment of such conditions. However, the anti-inflammatory molecular mechanisms of saffron in humans are still understudied and unclear. In this study, combining human serum metabolites and cell cultures, we evaluated the effect of circulating metabolites from the consumption of a patented saffron extract (Safr'InsideTM) on the chondrocytes and colon epithelial cell responses to inflammatory stress. Parametric or non-parametric Analysis of Variance with post hoc tests was performed. We demonstrated that human serum containing metabolites from saffron intake attenuated IL-1ß-stimulated production of PGE2 and MMP-13 in chondrocyte cells and limited the increase in ICAM-1, MCP-1, iNOS, and MMP-3 in human epithelial cells following combined IL-1ß and TNF-α inflammatory stimulation. Altogether, these data provide new findings into the mechanisms underlying the beneficial effects of saffron on chondrocytes and enterocyte cells at the cellular level and in the context of chronic inflammatory disorders.

Cardiac structure discontinuities revealed by ex-vivo microstructural characterization. A focus on the basal inferoseptal left ventricle region.

BACKGROUND: While the microstructure of the left ventricle (LV) has been largely described, only a few studies investigated the right ventricular insertion point (RVIP). It was accepted that the aggregate cardiomyocytes organization was much more complex due to the intersection of the ventricular cavities but a precise structural characterization in the human heart was lacking even if clinical phenotypes related to right ventricular wall stress or arrhythmia were observed in this region. METHODS: MRI-derived anatomical imaging (150 µm3) and diffusion tensor imaging (600 µm3) were performed in large mammalian whole hearts (human: N = 5, sheep: N = 5). Fractional anisotropy, aggregate cardiomyocytes orientations and tractography were compared within both species. Aggregate cardiomyocytes orientation on one ex-vivo sheep whole heart was then computed using structure tensor imaging (STI) from 21 µm isotropic acquisition acquired with micro computed tomography (MicroCT) imaging. Macroscopic and histological examination were performed. Lastly, experimental cardiomyocytes orientation distribution was then compared to the usual rule-based model using electrophysiological (EP) modeling. Electrical activity was modeled with the monodomain formulation. RESULTS: The RVIP at the level of the inferior ventricular septum presented a unique arrangement of aggregate cardiomyocytes. An abrupt, mid-myocardial change in cardiomyocytes orientation was observed, delimiting a triangle-shaped region, present in both sheep and human hearts. FA's histogram distribution (mean ± std: 0.29 ± 0.06) of the identified region as well as the main dimension (22.2 mm ± 5.6 mm) was found homogeneous across samples and species. Averaged volume is 0.34 cm3 ± 0.15 cm3. Both local activation time (LAT) and morphology of pseudo-ECGs were strongly impacted with delayed LAT and change in peak-to-peak amplitude in the simulated wedge model. CONCLUSION: The study was the first to describe the 3D cardiomyocytes architecture of the basal inferoseptal left ventricle region in human hearts and identify the presence of a well-organized aggregate cardiomyocytes arrangement and cardiac structural discontinuities. The results might offer a better appreciation of clinical phenotypes like RVIP-late gadolinium enhancement or uncommon idiopathic ventricular arrhythmias (VA) originating from this region.

Saffron extract interferes with lipopolysaccharide-induced brain activation of the kynurenine pathway and impairment of monoamine neurotransmission in mice.

Background: Although activation of inflammatory processes is essential to fight infections, its prolonged impact on brain function is well known to contribute to the pathophysiology of many medical conditions, including neuropsychiatric disorders. Therefore, identifying novel strategies to selectively counter the harmful effects of neuroinflammation appears as a major health concern. In that context, this study aimed to test the relevance of a nutritional intervention with saffron, a spice known for centuries for its beneficial effect on health. Methods: For this purpose, the impact of an acute oral administration of a standardized saffron extract, which was previously shown to display neuromodulatory properties and reduce depressive-like behavior, was measured in mice challenged with lipopolysaccharide (LPS, 830 µg/kg, ip). Results: Pretreatment with saffron extract (6.5 mg/kg, per os) did not reduce LPS-induced sickness behavior, preserving therefore this adaptive behavioral response essential for host defense. However, it interfered with delayed changes of expression of cytokines, chemokines and markers of microglial activation measured 24 h post-LPS treatment in key brain areas for behavior and mood control (frontal cortex, hippocampus, striatum). Importantly, this pretreatment also counteracted by that time the impact of LPS on several neurobiological processes contributing to inflammation-induced emotional alterations, in particular the activation of the kynurenine pathway, assessed through the expression of its main enzymes, as well as concomitant impairment of serotonergic and dopaminergic neurotransmission. Conclusion: Altogether, this study provides important clues on how saffron extract interferes with brain function in conditions of immune stimulation and supports the relevance of saffron-based nutritional interventions to improve the management of inflammation-related comorbidities.

Acute Effect of a Saffron Extract (Safr'InsideTM) and Its Main Volatile Compound on the Stress Response in Healthy Young Men: A Randomized, Double Blind, Placebo-Controlled, Crossover Study.

According to animal studies, saffron and its main volatile compound safranal may reduce biological and behavioral signs of acute stress. However, little is known about its impact in humans. This study investigated the acute effect of a saffron extract and safranal on the biological and psychological stress responses in healthy men experiencing a laboratory stress procedure. In this double-blind, placebo-controlled, randomized, cross-over study, 19 volunteers aged 18-25 received a single dose of 30 mg saffron extract (Safr'InsideTM), 0.06 mg synthetic safranal, or a placebo on three visits separated by a 28-day washout. Thirteen minutes after administration, participants were exposed to the Maastricht acute stress test (MAST). Salivary cortisol and cortisone were collected from 15 min before the MAST (and pre-dose), 3 min before the MAST, and then 15, 30, 45, 60, and 75 min after the MAST, and stress and anxiety were measured using visual analogic scales. Compared to the placebo, stress and anxiety were significantly toned down after Safranal and Safr'InsideTM administration and coupled with a delay in the times to peak salivary cortisol and cortisone concentrations (p < 0.05). Safr'InsideTM and its volatile compound seem to improve psychological stress response in healthy men after exposure to a lab-based stressor and may modulate the biological stress response.

Effects of a polyphenol-rich grape and blueberry extract (Memophenol™) on cognitive function in older adults with mild cognitive impairment: A randomized, double-blind, placebo-controlled study.

Background: Polyphenols are naturally occurring organic compounds found in plants. Research suggests that their intake reduces the risk of cognitive decline and related dementias. Grapes and blueberries are polyphenol-rich foods that have attracted attention for their potential cognitive-enhancing effects. Purpose: Examine the effects of supplementation with a standardized and patented polyphenol-rich grape and blueberry extract (Memophenol™) on cognitive function in older adults with mild cognitive impairment. Study design: Two-arm, 6 month, parallel-group, randomized, double-blind, placebo-controlled trial. Methods: One hundred and forty-three volunteers aged 60 to 80 years with mild cognitive impairment were supplemented with either 150 mg of Memophenol™, twice daily or a placebo. Outcome measures included computer-based cognitive tasks, the Behavior Rating Inventory of Executive Function (BRIEF-A), the Cognitive Failures Questionnaire, and the CASP-19. Results: Compared to the placebo, Memophenol™ supplementation was associated with greater improvements in the speed of information processing (p = 0.020), visuospatial learning (p = 0.012), and the BRIEF-A global score (p = 0.046). However, there were no other statistically significant between-group differences in the performance of other assessed cognitive tests or self-report questionnaires. Memophenol™ supplementation was well-tolerated with no reports of significant adverse reactions. Conclusion: The promising results from this trial suggest that 6-months of supplementation with Memophenol™ may improve aspects of cognitive function in adults with mild cognitive impairment. Further research will be important to expand on the current findings and identify the potential mechanisms of action associated with the intake of this polyphenol-rich extract.

Saffron extract (Safr'Inside™) improves anxiety related behaviour in a mouse model of low-grade inflammation through the modulation of the microbiota and gut derived metabolites.

Treatment of anxiety and depression predominantly centres around pharmacological interventions, which have faced criticism for their associated side effects, lack of efficacy and low tolerability. Saffron, which is reportedly well tolerated in humans, has been recognised for its antidepressant and anti-anxiety properties. Indeed, we previously reported upon the efficacy of saffron extract supplementation in healthy adults with subclinical anxiety. However, the molecular aetiology remains unclear. In a rodent model of low-grade chronic inflammation, we explored the impact of a saffron extract (Safr'Inside™) supplemented at a physiological dose, which equated to 22 ± 1.2 mg per day human equivalent dose for a person of 60 kg. Behavioural tests (Open Field task, Y maze, Novel object recognition), caecal 16S rRNA microbial sequencing, caecal 1H NMR metabolomic analysis and 2DE brain proteomic analyses were completed to probe gut-brain axis interactions. Time occupying the centre of the Open Field maze (OF) was increased by 62% in saffron supplemented animals. This improvement in anxiety-related behaviour coincided with gut microbial shifts, notably Akkermansia, Muribaculaceae, Christensenellacae and Alloprevotella which significantly increased in response to saffron supplementation. Akkermansia and Muribaculaceae abundance negatively correlated with the neurotoxic metabolite dimethylamine which was reduced in saffron supplemented animals. Brain proteomic analysis highlighted several significantly altered proteins including ketimine reductase mu-crystallin which also correlated with dimethylamine concentration. Both dimethylamine and ketimine reductase mu-crystallin were associated with OF performance. This may be indicative of a novel interaction across the gut-brain axis which contributes to anxiety-related disorders.

Circulating Human Serum Metabolites Derived from the Intake of a Saffron Extract (Safr'InsideTM) Protect Neurons from Oxidative Stress: Consideration for Depressive Disorders.

Increases in oxidative stress have been reported to play a central role in the vulnerability to depression, and antidepressant drugs may reduce increased oxidative stress in patients. Among the plants exerting anti-inflammatory and anti-oxidant properties, saffron, a spice derived from the flower of Crocus sativus, is also known for its positive effects on depression, potentially through its SSRI-like properties. However, the molecular mechanisms underlying these effects and their health benefits for humans are currently unclear. Using an original ex vivo clinical approach, we demonstrated for the first time that the circulating human metabolites produced following saffron intake (Safr'InsideTM) protect human neurons from oxidative-stress-induced neurotoxicity by preserving cell viability and increasing BNDF production. In particular, the metabolites significantly stimulated both dopamine and serotonin release. In addition, the saffron's metabolites were also able to protect serotonergic tone by inhibiting the expression of the serotonin transporter SERT and down-regulating serotonin metabolism. Altogether, these data provide new biochemical insights into the mechanisms underlying the beneficial impact of saffron on neuronal viability and activity in humans, in the context of oxidative stress related to depression.

Impact of intraventricular septal fiber orientation on cardiac electromechanical function.

Cardiac fiber direction is an important factor determining the propagation of electrical activity, as well as the development of mechanical force. In this article, we imaged the ventricles of several species with special attention to the intraventricular septum to determine the functional consequences of septal fiber organization. First, we identified a dual-layer organization of the fiber orientation in the intraventricular septum of ex vivo sheep hearts using diffusion tensor imaging at high field MRI. To expand the scope of the results, we investigated the presence of a similar fiber organization in five mammalian species (rat, canine, pig, sheep, and human) and highlighted the continuity of the layer with the moderator band in large mammalian species. We implemented the measured septal fiber fields in three-dimensional electromechanical computer models to assess the impact of the fiber orientation. The downward fibers produced a diamond activation pattern superficially in the right ventricle. Electromechanically, there was very little change in pressure volume loops although the stress distribution was altered. In conclusion, we clarified that the right ventricular septum has a downwardly directed superficial layer in larger mammalian species, which can have modest effects on stress distribution.NEW & NOTEWORTHY A dual-layer organization of the fiber orientation in the intraventricular septum was identified in ex vivo hearts of large mammals. The RV septum has a downwardly directed superficial layer that is continuous with the moderator band. Electrically, it produced a diamond activation pattern. Electromechanically, little change in pressure volume loops were noticed but stress distribution was altered. Fiber distribution derived from diffusion tensor imaging should be considered for an accurate strain and stress analysis.

Prevention of Stress-Induced Depressive-like Behavior by Saffron Extract Is Associated with Modulation of Kynurenine Pathway and Monoamine Neurotransmission.

Depressive disorders are a major public health concern. Despite currently available treatment options, their prevalence steadily increases, and a high rate of therapeutic failure is often reported, together with important antidepressant-related side effects. This highlights the need to improve existing therapeutic strategies, including by using nutritional interventions. In that context, saffron recently received particular attention for its beneficial effects on mood, although the underlying mechanisms are poorly understood. This study investigated in mice the impact of a saffron extract (Safr'Inside™; 6.25 mg/kg, per os) on acute restraint stress (ARS)-induced depressive-like behavior and related neurobiological alterations, by focusing on hypothalamic-pituitary-adrenal axis, inflammation-related metabolic pathways, and monoaminergic systems, all known to be altered by stress and involved in depressive disorder pathophysiology. When given before stress onset, Safr'Inside administration attenuated ARS-induced depressive-like behavior in the forced swim test. Importantly, it concomitantly reversed several stress-induced monoamine dysregulations and modulated the expression of key enzymes of the kynurenine pathway, likely reducing kynurenine-related neurotoxicity. These results show that saffron pretreatment prevents the development of stress-induced depressive symptoms and improves our understanding about the underlying mechanisms, which is a central issue to validate the therapeutic relevance of nutritional interventions with saffron in depressed patients.

Saffron Extract-Induced Improvement of Depressive-Like Behavior in Mice Is Associated with Modulation of Monoaminergic Neurotransmission.

Depressive disorders represent a major public health concern and display a continuously rising prevalence. Importantly, a large proportion of patients develops aversive side effects and/or does not respond properly to conventional antidepressants. These issues highlight the need to identify further therapeutic strategies, including nutritional approaches using natural plant extracts with known beneficial impacts on health. In that context, growing evidence suggests that saffron could be a particularly promising candidate. This preclinical study aimed therefore to test its antidepressant-like properties in mice and to decipher the underlying mechanisms by focusing on monoaminergic neurotransmission, due to its strong implication in mood disorders. For this purpose, the behavioral and neurobiochemical impact of a saffron extract, Safr'Inside™ (6.5 mg/kg per os) was measured in naïve mice. Saffron extract reduced depressive-like behavior in the forced swim test. This behavioral improvement was associated with neurobiological modifications, particularly changes in serotonergic and dopaminergic neurotransmission, suggesting that Safr'Inside™ may share common targets with conventional pharmacological antidepressants. This study provides useful information on the therapeutic relevance of nutritional interventions with saffron extracts to improve management of mood disorders.

Effects of Saffron Extract Supplementation on Mood, Well-Being, and Response to a Psychosocial Stressor in Healthy Adults: A Randomized, Double-Blind, Parallel Group, Clinical Trial.

Anxiety, stress, and low mood are closely related and may contribute to depressive symptoms. Among non-pharmacological solutions to improve subclinical mood symptoms and resilience to stress, natural products such as saffron-identified as promising following preliminary beneficial effects in major depressive disorder-represent a relevant strategy. This study aimed to assess the efficacy of 8 weeks' supplementation with 30 mg standardized saffron extract on emotional well-being in healthy adults with subclinical feelings of low mood and anxiety and/or stress and evaluate the acute effect of saffron in response to a lab-based psychosocial stressor. The study adopted a double-blind, randomized, parallel groups design in which 56 healthy male and female individuals (18-54 years) received either a saffron extract or a placebo for 8 weeks. Chronic effects of saffron on subjective anxiety, stress, and depressive feelings were assessed using a questionnaire battery [including Profile of Mood State-2, (POMS)] and acute effects in response to a lab-based psychosocial stressor were measured through psychological and physiological parameters. Urinary crocetin levels were quantified. Participants who received the saffron extract reported reduced depression scores and improved social relationships at the end of the study. Urinary crocetin levels increased significantly with saffron supplementation and were correlated with change in depression scores. The typical stress-induced decrease in heart rate variability (HRV) during exposure to the stressor was attenuated following acute saffron intake. Saffron extract appears to improve subclinical depressive symptoms in healthy individuals and may contribute to increased resilience against the development of stress-related psychiatric disorders. Clinical trials number: NCT03639831.

Acute Intake of a Grape and Blueberry Polyphenol-Rich Extract Ameliorates Cognitive Performance in Healthy Young Adults During a Sustained Cognitive Effort.

Despite an increasing level of evidence supporting the individual beneficial effect of polyphenols on cognitive performance, information related to the potential synergistic action of these phytonutrients on cognitive performance during a prolonged cognitive effort is currently lacking. This study investigated the acute and sustained action of a polyphenols-rich extract from grape and blueberry (PEGB), on working memory and attention in healthy students during a prolonged and intensive cognitive effort. In this randomised, cross-over, double blind study, 30 healthy students consumed 600 mg of PEGB or a placebo. Ninety minutes after product intake, cognitive functions were assessed for one hour using a cognitive demand battery including serial subtraction tasks, a rapid visual information processing (RVIP) task and a visual analogical scale. Flow-mediated dilation (FMD) and plasma flavan-3-ols metabolites quantification were also performed. A 2.5-fold increase in serial three subtraction variation net scores was observed following PEGB consumption versus placebo (p < 0.001). A trend towards significance was also observed with RVIP percentage of correct answers (p = 0.058). No treatment effect was observed on FMD. Our findings suggest that consumption of PEGB coupled with a healthy lifestyle may be a safe alternative to acutely improve working memory and attention during a sustained cognitive effort.

Compartmentalized Structure of the Moderator Band Provides a Unique Substrate for Macroreentrant Ventricular Tachycardia.

Background Papillary muscles are an important source of ventricular tachycardia (VT). Yet little is known about the role of the right ventricular (RV) endocavity structure, the moderator band (MB). The aim of this study was to determine the characteristics of the MB that may predispose to arrhythmia substrates. Methods Ventricular wedge preparations with intact MBs were studied from humans (n=2) and sheep (n=15; 40-50 kg). RV endocardium was optically mapped, and electrical recordings were measured along the MB and septum. S1S2 pacing of the RV free wall, MB, or combined S1-RV S2-MB sites were assessed. Human (n=2) and sheep (n=4) MB tissue constituents were assessed histologically. Results The MB structure was remarkably organized as 2 excitable, yet uncoupled compartments of myocardium and Purkinje. In humans, action potential duration heterogeneity between MB and RV myocardium was found (324.6±12.0 versus 364.0±8.4 ms; P<0.0001). S1S2-MB pacing induced unidirectional propagation via MB myocardium, permitting sustained macroreentrant VT. In sheep, the incidence of VT for RV, MB, and S1-RV S2-MB pacing was 1.3%, 5.1%, and 10.3%. Severing the MB led to VT termination, confirming a primary arrhythmic role. Inducible preparations had shorter action potential duration in the MB than RV (259.3±45.2 versus 300.7±38.5 ms; P<0.05), whereas noninducible preparations showed no difference (312.0±30.3 versus 310.0±24.6 ms, respectively). Conclusions The MB presents anatomic and electrical compartmentalization between myocardium and Purkinje fibers, providing a substrate for macroreentry. The vulnerability to sustain VT via this mechanism is dependent on MB structure and action potential duration gradients between the RV free wall and MB.

Platelet function and microparticle levels in atrial fibrillation: Changes during the acute episode.

BACKGROUND: Thrombotic risk constitutes a major complication of atrial fibrillation (AF). Platelets and microparticles (MPs) are important for hemostasis and thrombosis, however their participation during AF is not well known. The aim of this study was to characterize platelet function and MPs procoagulant and fibrinolytic activity in AF patients and to determine the effects of an acute-AF episode. METHODS: Blood was collected from paroxysmal (21) and persistent (16) AF patients referred for AF catheter ablation. Ten patients in sinus rhythm for 10days were induced in AF allowing comparisons of left atrium samples before and after induction. Platelet aggregation with ADP, TRAP, collagen, and ristocetin was studied. Platelet surface expression of PAR-1, αIIbß3, GPIb and P-selectin were evaluated by flow cytometry, and MPs-associated procoagulant and fibrinolytic activity levels were determined by functional assays. RESULTS: A specific reduction in platelet aggregation to TRAP, activating the thrombin receptor PAR-1, was found in all AF patients. No differences in platelet receptor expression were found. Yet, after acute-induced AF, the platelet response was improved. Furthermore, a significant decrease of left atrium tissue factor-dependent procoagulant activity of MPs was observed. CONCLUSION: Acute episodes of AF results in a decrease in MPs-associated tissue factor activity, possibly corresponding to consumption, which in turn favors coagulation and the local production of thrombin. A decreased platelet basal aggregation to TRAP may result from PAR1 desensitization, whereas the improved response after an induced episode of AF suggests activation of coagulation and PAR1 re-sensitization.

Antibody-functionalized magnetic polymersomes: in vivo targeting and imaging of bone metastases using high resolution MRI.

Multifunctional polymersomes loaded with maghemite nanoparticles and grafted with an antibody, directed against human endothelial receptor 2, are developed as novel MRI contrast agents for bone metastasis imaging. Upon administration in mice bearing bone tumor grown from human breast cancer cells, MR images show targeting and enhanced retention of antibody-labeled polymersomes at the tumor site.

Comprehensive phenotyping of salt-induced hypertensive heart disease in living mice using cardiac magnetic resonance.

OBJECTIVES: To characterise the effects of high-salt diet (HSD) on left ventricular (LV) mass, systolic function and coronary reserve in living mice using cardiac magnetic resonance imaging (MRI). METHODS: Thirty C57BL/6 1-month-old female mice were fed either a control (n = 15) or an HSD (n = 15). After 3 months, LV volumes, ejection fraction and mass were assessed using time-resolved three-dimensional (3D) black-blood manganese-enhanced MRI, and coronary flow velocity reserve (CFVR) was assessed using dynamic MR angiography at rest and during adenosine-induced hyperaemia. Hearts were excised to assess LV wet mass and micro-vascular remodelling at histology. RESULTS: Micro-vascular remodelling was found at histology in all investigated hearts from the HSD group and none from the control group. No difference between the HSD and control groups was found in terms of heart weight, LV volumes and ejection fraction. Heart to body weight ratio was higher in the HSD group (4.39 ± 0.24 vs 4.02 ± 0.16 mg/g, P < 0.001), because of lower body weight (22.3 ± 0.9 vs 24.0 ± 1.4 g, P < 0.001). CFVR was lower in the HSD group (1.73 ± 0.11 vs 1.94 ± 0.12, P < 0.001). CONCLUSIONS: Phenotyping of hypertensive heart disease is feasible in living mice using dynamic MR angiography and time-resolved 3D black-blood manganese-enhanced MRI. HSD is associated with early impairment of coronary reserve, before the onset of significant hypertrophy.

In vivo high-resolution 3D overhauser-enhanced MRI in mice at 0.2 T.

Overhauser-enhanced MRI (OMRI) offers the potentiality of detecting low-concentrated species generated by specific biological processes. However molecular imaging applications of OMRI need significant improvement in spatial localization. Here it is shown that 3D-OMRI of a free radical injected in tumor-bearing mice can be performed at high anatomical resolution at a constant field. A 30 mm cavity operating at 5.43 GHz was inserted in a C-shaped magnet for proton MRI at 0.194 T. Nude mice with or without brain-implanted C6 rat glioma were positioned in the cavity and injected with TOPCA (1-oxyl-2,2,5,5-tetramethyl-2,5-dihydro-1H-pyrrole-3-carboxylic acid). OMRI was performed in 3D within several minutes in the brain region without high overheating of the animals. Voxel size was 0.5 × 0.5 × 1 mm³ , providing good delineation of brain regions. Signal amplifications ranged from 2 in tumors to 10 in vessels several minutes after TOPCA injection. Time-course of signal enhancement could be measured by 2D OMRI at 15 s time intervals in a localized thin slice. The method opens the way for molecular imaging of biological activities able to generate OMRI-visible free radicals.

In vivo MR tracking of therapeutic microglia to a human glioma model.

A knowledge of the spatial localization of cell vehicles used in gene therapy against glioma is necessary before launching therapy. For this purpose, MRI cell tracking is performed by labeling the cell vehicles with contrast agents. In this context, the goal of this study was to follow noninvasively the chemoattraction of therapeutic microglial cells to a human glioma model before triggering therapy. Silica nanoparticles grafted with gadolinium were used to label microglia. These vehicles, expressing constitutively the thymidine kinase suicide gene fused to the green fluorescent protein gene, were injected intravenously into human glioma-bearing nude mice. MRI was performed at 4.7 T to track noninvasively microglial accumulation in the tumor. This was followed by microscopy on brain slices to assess the presence in the glioma of the contrast agents, microglia and fusion gene through the detection of silica nanoparticles grafted with tetramethyl rhodamine iso-thiocyanate, 3,3'-dioctadecyloxacarbocyanine perchlorate and green fluorescent protein fluorescence, respectively. Finally, gancyclovir was administered systemically to mice. Human microglia were detectable in living mice, with strong negative contrast on T(2) *-weighted MR images, at the periphery of the glioma only 24 h after systemic injection. The location of the dark dots was identical in MR microscopy images of the extracted brains at 9.4 T. Fluorescence microscopy confirmed the presence of the contrast agents, exogenous microglia and suicide gene in the intracranial tumor. In addition, gancyclovir treatment allowed an increase in mice survival time. This study validates the MR tracking of microglia to a glioma after systemic injection and their use in a therapeutic strategy against glioma.

Hormonal, hypothalamic and striatal responses to reduced body weight gain are attenuated in anorectic rats bearing small tumors.

Lack of compensatory or even reduced food intake is frequently observed in weight-losing cancer patients and contributes to increased morbidity and mortality. Our previous work has shown increased transcription factor expression in the hypothalamus and ventral striatum of anorectic rats bearing small tumors. mRNA expression of molecules known to be involved in pathways regulating appetite in these structures was therefore assessed in this study. Given that pain, pro-inflammatory cytokines and metabolic hormones can modify food intake, spinal cord cellular activation patterns and plasma concentrations of cytokines and hormones were also studied. Morris hepatoma 7777 cells injected subcutaneously in Buffalo rats provoked a 10% lower body weight and 15% reduction in food intake compared to free-feeding tumor-free animals 4 weeks later when the tumor represented 1-2% of body mass. No differences in spinal cord activation patterns or plasma concentration of pro-inflammatory cytokines were observed between groups. However, the changes in plasma ghrelin and leptin concentrations found in food-restricted weight-matched rats in comparison to ad libitum-fed animals did not occur in anorectic tumor-bearing animals. Real-time PCR showed that tumor-bearing rats did not display the increase in hypothalamic agouti-related peptide mRNA observed in food-restricted weight-matched animals. In addition, microarray analysis and real-time PCR revealed increased ventral striatal prostaglandin D synthase expression in food-restricted animals compared to anorectic tumor-bearing rats. These findings indicate that blunted hypothalamic AgRP mRNA expression, probably as a consequence of relatively high leptin and low ghrelin concentrations, and reduced ventral striatal prostaglandin D synthesis play a role in maintaining cancer-associated anorexia.