•Fish hydrolysate contains n-3 LC-PUFAs and low molecular weight peptides.•Fish hydrolysate prevents age-related short-term memory deficits.•Fish hydrolysate affects navigation strategies during ...spatial learning.•Fish hydrolysate possesses immunomodulatory and anxiolytic properties.•Fish hydrolysate is promising for the prevention of age-related cognitive decline.
Brain aging is characterized by a decline in cognitive functions, which can lead to the development of neurodegenerative pathologies. Age-related spatial learning and memory deficits are associated with a chronic low-grade inflammation. Anxiety disorders and stress response alterations, occurring for a part of the elderly, have also been linked to an increased neuroinflammation and thus, an accelerated cognitive decline. Nutrition is an innovative strategy to prevent age-related cognitive impairments. Among the nutrients, n-3 long chain polyunsaturated fatty acids (LC-PUFAs) and low molecular weight peptides from proteins, especially those from marine resources, are good candidates for their immunomodulatory, anxiolytic and neuroprotective properties. The aim of this study is to determine the combined effect of n-3 LC-PUFAs and low molecular weight peptides on cognitive functions, and their mechanism of action. We are the first to show that a dietary supplementation with a fish hydrolysate containing n-3 LC-PUFAs and low molecular weight peptides prevented the age-related spatial short-term memory deficits and modulated navigation strategies adopted during spatial learning. In addition, the fish hydrolysate displayed anxiolytic activities with the reduction of anxiety-like behaviour in aged mice, restored the plasmatic corticosterone levels similar to adult animals following an acute stress and modulated the hypothalamic stress response. These effects on behaviour can be explained by the immunomodulatory and neuroprotective properties of the fish hydrolysate that limited microgliosis in vivo, decreased LPS-induced expression of pro-inflammatory cytokines and increased the expression of growth factors such as BDNF and NGF in vitro. Thus, n-3 LC-PUFAs and low molecular weight peptides contained in the fish hydrolysate can play an important role in the limitation of neuroinflammation and stress response alterations during aging and represent a potential strategy for the prevention of age-related cognitive decline.
Obesity is a well-known syndrome of excessive body fat in cats (Felis catus) that affects the health, welfare and lifespan of animals. Consequently, different diet strategies aiming to reduce ...voluntary feed intake in cats have been studied. One of these consists in reducing energy intake based on reduction of feed intake. Several clinical studies have demonstrated that dietary fibre inclusion in food reduced efficiently voluntary feed intake (VFI) in dogs. However, little clinical data is available regarding the impact of dietary fibre inclusion on cat’s feeding behaviours and VFI. The aim of the current study was to test the performance of sugar cane fibre included at three different levels in extruded feline diets. The main purpose was to measure the impact of fibre inclusion on the cats’ VFI, while maintaining palatability. Four feline diets were formulated with different inclusion levels of sugar cane fibre expressed on an as fed basis (0% sugar cane fibre (control), 3.7% of sugar cane fibre (SF3.7), 5.5% of sugar cane fibre (SF5.5) and 7.3% sugar cane fibre (SF7.3)). The VFI and palatability were evaluated in two different methods: a new method using 79 cats, called ‘consumption kinetics’ based on the dynamic measure of cat’s daily consumptions in ad libitum conditions providing information about cat’s feeding pattern, and the standard palatability two-bowl (versus) test using more than 30 cats. All foods had identical palatability performance, regardless of sugar cane fibre inclusion level, while the VFI of products containing 5.5% and 7.3% sugar cane fibre decreased significantly compared to the control diet. The level of supplementation of sugar cane fibre was efficient to reduce felines VFI without impairing food palatability level, and may be a useful ingredient to add to feline diets to improve the success of the weight management programs.
Twelve new dinucleotide microsatellite loci of the whitefly, Bemisia tabaci, were obtained from enriched genomic libraries. Three polymerase chain reaction multiplex sets comprising three, five and ...four loci were optimized and characterized across 133 B. tabaci females from Israeli rearings and natural populations collected in four Mediterranean countries (Tunisia, France, Spain and Morocco). There were three to 24 alleles per locus and the observed heterozygosity was from 0.084 to 0.420. Deviation from Hardy-Weinberg equilibrium was detected at four loci associated with significant heterozygote deficiencies due to null alleles and presence of subpopulations that were mostly in the Tunisian sample. The 12 loci carried independent information.
La neuroinflammation représente un mécanisme de défense crucial du système nerveux central contre les agents pathogènes afin d’assurer un retour à l’homéostasie dans le cerveau. Cette réponse ...immunitaire physiologique est orchestrée par les cellules microgliales, les cellules du système immunitaire cérébral. Cependant, une production soutenue et incontrôlée des facteurs pro-inflammatoires associée à une activation microgliale ainsi qu’une dérégulation de la résolution de l’inflammation contribuent à l’apparition d’une inflammation chronique à bas bruit, comme observé au cours du vieillissement et dans les maladies neurodégénératives, pouvant entraîner des lésions neuronales responsables, en partie, des troubles cognitifs. La nutrition apparaît comme une stratégie innovante pour prévenir les altérations liées à la neuroinflammation. Les acides gras polyinsaturés n-3 (AGPI n-3) à longue chaîne et les peptides de petits poids moléculaires sont de bons candidats en raison de leurs propriétés immunomodulatrices et pro-résolutives via la production d’oxylipines. L’objectif de cette étude est d’évaluer le potentiel anti-inflammatoire du Mnemosyss®, un hydrolysat de coproduits marins combinant ces composés, sur l’inflammation aiguë et de comparer cet effet à une supplémentation en DHA seul.
Des souris âgées de 7 semaines ont été supplémentées pendant 18jours avec du Mnemosyss®, du DHA ou une solution contrôle. L’inflammation aiguë a été induite par une injection intrapéritonéale de lipopolysaccharide (LPS) et les souris ont été euthanasiées 2h après. Les analyses ont été effectuées dans l’hippocampe. L’expression des marqueurs inflammatoires, des marqueurs d’activation microgliale a été mesurée par RT-qPCR. L’expression protéique de IκB et de NF-κB a été quantifiée par Western-Blot. Enfin, la composition en oxylipines a été évaluée par chromatographie liquide couplée à la spectrométrie de masse.
En réponse au LPS, la supplémentation en Mnemosyss® diminue l’expression des cytokines pro-inflammatoires IL-6 (p<0,001), IL-1β (p<0,001) et TNF-α (p<0,01) alors que le DHA réduit uniquement l’expression de l’IL-6 (p<0,01). Cette baisse de l’expression des cytokines pro-inflammatoires est associée à une augmentation de l’expression protéique de IκB (p<0,05 et p<0,01 vs. DHA et contrôle, respectivement) et à une modulation des marqueurs d’activation microgliale dans l’hippocampe. Les effets du Mnemosyss® pourraient être dus, en partie, au changement du profil en oxylipines vers un profil plus anti-inflammatoire par rapport à la supplémentation en DHA.
Cette étude démontre le pouvoir anti-inflammatoire et pro-résolutif du Mnemosyss®. Celui-ci est même plus efficace que le DHA seul pourtant apporté en plus grande quantité suggérant un effet des peptides seuls ou une potentialisation du DHA par les peptides. Il pourrait donc être proposé pour freiner l’inflammation au cours du vieillissement ou lors de pathologies inflammatoires aiguës ou chroniques.
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