Inflammation is a vital protective response to threats, but it can turn harmful if chronic and uncontrolled. Key elements involve pro-inflammatory cells and signaling pathways, including the secretion of pro-inflammatory cytokines, NF-κB, reactive oxygen species (ROS) production, and the activation of the NLRP3 inflammasome. Ampelopsis grossedentata, or vine tea, contains dihydromyricetin (DHM) and myricetin, which are known for their various health benefits, including anti-inflammatory properties. Therefore, the aim of this study is to assess the impact of an extract of A. grossedentata leaves (50 µg/mL) on inflammation factors such as inflammasome, pro-inflammatory pathways, and macrophage polarization, as well as its antioxidant properties, with a view to combating the development of low-grade inflammation. Ampelopsis grossedentata extract (APG) significantly decreased ROS production and the secretion of pro-inflammatory cytokines (IFNγ, IL-12, IL-2, and IL-17a) in human leukocytes. In addition, APG reduced LPS/IFNγ -induced M1-like macrophage polarization, resulting in a significant decrease in the expression of the pro-inflammatory cytokines TNF-α and IL-6, along with a decrease in the percentage of M1 macrophages and an increase in M0 macrophages. Simultaneously, a significant decrease in NF-κB p65 phosphorylation and in the expression of inflammasome genes (NLRP3, IL-1β and Caspase 1) was observed. The results suggest that Ampelopsis grossedentata could be a promising option for managing inflammation-related chronic diseases. Further research is needed to optimize dosage and administration methods.

Excess weight and obesity are the fifth leading cause of death globally, and sustained efforts from health professionals and researchers are required to mitigate this pandemic-scale problem. Polyphenols and flavonoids found in Aspalathus linearis—a plant widely consumed as Rooibos tea—are increasingly being investigated for their positive effects on various health issues including inflammation. The aim of our study was to examine the effect of Rooibos extract on obesity and the associated low-grade chronic inflammatory state by testing antioxidant activity, cytokine secretions, macrophage polarization and the differentiation of human adipocytes through the development of adipospheroids. Rooibos extract significantly decreased ROS production and the secretion of pro-inflammatory cytokines (IFN-γ, IL-12, IL-2 and IL-17a) in human leukocytes. Additionally, Rooibos extract down-regulated LPS-induced macrophage M1 polarization, shown by a significant decrease in the expression of pro-inflammatory cytokines: TNFα, IL-8, IL-6, IL-1β and CXCL10. In addition, Rooibos inhibited intracellular lipid accumulation and reduced adipogenesis by decreasing the expression of PPARγ, Ap2 and HSL in adipospheroids. A significant decrease in leptin expression was noted and this, more interestingly, was accompanied by a significant increase in adiponectin expression. Using a co-culture system between macrophages and adipocytes, Rooibos extract significantly decreased the expression of all studied pro-inflammatory cytokines and particularly leptin, and increased adiponectin expression. Thus, adding Rooibos tea to the daily diet is likely to prevent the development of obesity associated with chronic low-level inflammation.

Background/Objectives: Inflammation is a vital response of the immune system, frequently linked to the development and progression of numerous chronic and autoimmune diseases. Targeting inflammation represents an attractive strategy to prevent and treat these pathologies. In this context, many pathways, including pro-inflammatory cytokines secretion, NFκB activation, reactive oxygen species (ROS) production, inflammasome activation and arachidonic acid metabolism could be highlighted and addressed. Several plant materials have traditionally been used as effective and non-harmful anti-inflammatory agents. However, well-established scientific evidence is lacking, and their mechanisms of action remain unclear. The current article compares the effects of seven plant extracts, including Quercus robur L. (Oak), Plantago lanceolata L. (narrowleaf plantain), Plantago major L. (broadleaf plantain), Helichrysum stoechas L. (immortelle or helichrysum), Leontopodium nivale alpinum Cass. (edelweiss), Medicago sativa L. (alfafa) and Capsella bursa-pastoris Moench (shepherd’s purse) on different inflammatory pathways. Results: All of the plant extracts significantly affected ROS production, but their action on cytokine production was more variable. As the Quercus robur extract showed the highest efficacy in our models, it was subsequently assessed on several inflammatory signaling pathways. Quercus robur significantly decreased the secretion of IFNγ, IL-17a, IL-12, IL-2, IL-1β and IL-23 in stimulated human leucocytes, and the expression of TNFα, IL-6, IL-8, IL-1β and CXCL10 in M1-like macrophages. Additionally, a significant reduction in PGE2 secretion, COX2, NLRP3, caspase1 and STAT3 expression and NFκB p65 phosphorylation was observed. Conclusions: Our results clearly indicate that Quercus robur has a potent anti-inflammatory effect, making it a promising candidate for both the treatment and prevention of inflammation and related diseases, thereby promoting overall well-being.

Obesity, a global health crisis, is linked to chronic low-grade inflammation and an increased risk of developing various chronic diseases, including psoriasis. Probiotics, postbiotics, and fermented foods have shown promise in combating inflammation and obesity. This study aimed to develop and characterize a chicory extract fermented with Bacteroides fragilis (C-B. fragilis) and its supernatant (phyto-postbiotic supernatant, PPS) as potential treatments for obesity, inflammation, and psoriasis. Polyphenols, organic acids, and amino acids were identified in the metabolic profile of C-B. fragilis. PPS and C-B. fragilis extract both revealed potent anti-inflammatory, anti-obesity, and antioxidant activities. In vitro assays highlighted that PPS significantly reduced the production of reactive oxygen species (ROS), the expression of pro-inflammatory cytokines (TNF-α, IL-6, IL-8) in macrophages, and the secretion of IL-1β in LPS-stimulated PBMCs. Moreover, PPS decreased triglyceride content in human adipocytes and modulated the expression of leptin and adiponectin. Regarding psoriasis, PPS reduced pro-inflammatory cytokines (IL-6, IL-1β) in both psoriatic keratinocytes and a co-culture model mimicking the skin-adipose tissue interface. In addition, PPS lowered S100 calcium-binding protein A7 (S100A7) expression in the co-culture model, suggesting a potential role in restoring skin barrier function. In summary, our results highlight the potential of PPS extract (supernatant of chicory fermentation by Bacteroides fragilis) as a promising therapeutic strategy for the management of obesity-related inflammation and psoriasis.

Les produits naturels, qu'il s'agisse des plantes, des algues ou des micro-organismes, constituent une source majeure de composés bioactifs d'intérêt dans la prévention ou le traitement de diverses pathologies. De par leurs propriétés anti-inflammatoires et antioxydantes, ceux-ci sont très étudiés dans le cadre de pathologies complexes telles que, par exemple, l'obésité. En effet, l'obésité, caractérisée par une expansion excessive du tissu adipeux, est associée à une inflammation chronique de bas grade, ce qui participe au développement et/ou à l'entretien de multiples pathologies, i.e métaboliques, cardiovasculaires, auto-immunes, cutanées et de certains cancers. Aussi, cibler à la fois le tissu adipeux et l'inflammation qui lui est associée peut constituer une stratégie privilégiée pour prévenir l'apparition, l'agressivité et la récidive de certaines maladies.Le premier volet de ce travail a consisté à développer des PHYTO-POSTBIOTIQUES (végétaux fermentés par une bactérie). Pour cela, la sélection de onze souches bactériennes ainsi que de deux prébiotiques à fermenter a permis de développer et de comparer l'activité d'une vingtaine d'extraits. Un screening, permettant de comparer leur capacité à réduire la production d'espèces oxygénées réactives (ERO) leucocytaires, a permis de sélectionner deux extraits avec des effets antioxydants prometteurs : 1/ un extrait issu de la fermentation de la chicorée par Akkermansia muciniphila (C-Akm, liste Novel Food de l'EFSA) et, 2/ un extrait issu de la fermentation de la chicorée par Bacteroides fragilis (C-B.fragilis, sur aucune liste) et son surnageant (PPS).Ces extraits ont été évalués sur leur capacité à cibler des biomarqueurs inflammatoires et de situation de surcharge pondérale en utilisant différents modèles cellulaires. Ainsi, C-Akm diminue la production de cytokines pro-inflammatoires (IFNγ et IL-17A), module à la baisse la polarisation en macrophages pro-inflammatoires M1 et augmente la sécrétion d'adiponectine. L'extrait PPS, quant à lui, diminue la polarisation des macrophages M1 et réduit l'accumulation lipidique au niveau adipocytaire, ce qui suggère un effet bénéfique potentiel de cet extrait dans la prévention du surpoids/obésité.Au vu des liens forts existants entre obésité et psoriasis, le second volet de cette thèse a consisté à explorer l'impact de l'extrait de C-B.fragilis et de son PPS sur le psoriasis, notamment en situation de surcharge pondérale. En utilisant des kératinocytes psoriasiques humains (issus de biopsies), nous avons montré que l'extrait PPS est celui qui semble le plus actif sur l'inflammation cutanée en diminuant la sécrétion de cytokines pro-inflammatoires (IL-6 et IL-1β) et de médiateurs de l'inflammation (S100A7), mais aussi en augmentant l'expression de la filaggrine impliquée dans la fonction de barrière et sous-régulée en situation de psoriasis.Par ailleurs, nous avons évalué un extrait de plante, i.e. Ampelopsis grossedentata (sélectionnée dans le Labcom comme anti-inflammatoire, liste IECIC), pour potentiellement l'utiliser en synergie avec le PPS en prévention/thérapie du psoriasis. Ampelopsis grossedentata présente des effets antioxydants et anti-inflammatoires intéressants en freinant la production d'ERO, en diminuant la polarisation des macrophages M1, en réduisant la production de cytokines pro-inflammatoires (IFNγ, IL-12, IL-2 et IL-17A) et en mettant en jeu la voie NF-κB et celle de l'inflammasome. Cependant, au cours de nos expériences préliminaires, aucun effet synergique n'a été montré entre l'extrait PPS et l'extrait d'Ampelopsis grossedentata.Bien que des études complémentaires soient nécessaires pour confirmer leur efficacité en clinique ainsi que leur sécurité à long terme, ces résultats sont prometteurs et ouvrent la voie à une stratégie préventive/complémentaire aux traitements classiques dans une prise en charge de l'obésité, de l'inflammation et d'une pathologie inflammatoire cutanée telle que le psoriasis.