Anti-inflammatory and immunomodulatory activity of Mangifera indica L. reveals the modulation of COX-2/mPGES-1 axis and Th17/Treg ratio

In the context of inflammation and immunity, there are fragmented and observational studies relating to the pharmacological activity of Mangifera indica L. and its main active component, mangiferin. Therefore, we aimed to analyze the potential beneficial effects of this plant extract (MIE, 90% in mangiferin) in a mouse model of gouty arthritis, to allow the evaluation of cellular immune phenotypes and the biochemical mechanism/s beyond MIE activity. Gouty arthritis was induced by the intra-articular administration of MSU crystals (200μg 20μl^-1), whereas MIE (0.1-10mgkg^-1) or corresponding vehicle (DMSO/saline 1:3) were orally administrated concomitantly with MSU (time 0), 6 and 12h after the stimulus. Thereafter, knee joint score and oedema were evaluated in addition to western blot analysis for COX-2/mPGES-1 axis. Moreover, the analysis of pro/anti-inflammatory cyto-chemokines coupled with the phenotyping of the cellular infiltrate was performed. Treatment with MIE revealed a dose-dependent reduction in joint inflammatory scores with maximal inhibition observed at 10mgkg^-1. MIE significantly reduced leukocyte infiltration and activation and the expression of different pro-inflammatory cyto-chemokines in inflamed tissues. Furthermore, biochemical analysis revealed that MIE modulated COX-2/mPGES-1 and mPGDS-1/PPARγ pathways. Flow cytometry analysis also highlighted a prominent modulation of inflammatory monocytes (CD11b⁺/CD115⁺/LY6C^hi), and Treg cells (CD4⁺/CD25⁺/FOXP3⁺) after MIE treatment. Collectively, the results of this study demonstrate a novel function of MIE to positively affect the local and systemic inflammatory/immunological perturbance in the onset and progression of gouty arthritis.

Comparative study of the effect of starches from five different sources on the rheological properties of gluten-free model doughs

We investigated the effect of wheat (WS), corn (CS), tapioca (TS), sweet potato (SS) and potato (PS) starches on the rheological properties of starch-hydroxypropylmethylcellulose (HPMC) model doughs. Significant differences were found among model doughs made with different starches in terms of water absorption, development time, and strength. The PS-HPMC dough presented higher maximum creep compliance, followed successively by SS-, TS-, CS-, and WS-HPMC doughs, and the same order was found for the degree of dependence of G' on frequency sweep, suggesting that the resistance to deformation depends on network structure stability. More water distributed between hydration sites of HPMC and starch surface, leading to more hydrogen bonds and the formation of stable network. In conclusion, the rheological properties of model doughs are largely due to variation in structural and physicochemical properties of different starches, as well as varying interactions between different starches and HPMC.

1-Octanol, a self-inhibitor of spore germination in Penicillium camemberti

Penicillium camemberti is a technologically relevant fungus used to manufacture mold-ripened cheeses. This fungal species produces many volatile organic compounds (VOCs) including ammonia, methyl-ketones, alcohols and esters. Although it is now well known that VOCs can act as signaling molecules, nothing is known about their involvement in P. camemberti lifecycle. In this study, spore germination was shown to be self-regulated by quorum sensing in P. camemberti. This phenomenon, also called "crowding effect", is population-dependent (i.e. observed at high population densities). After determining the volatile nature of the compounds involved in this process, 1-octanol was identified as the main compound produced at high-spore density using GC-MS. Its inhibitory effect was confirmed in vitro and 3 mM 1-octanol totally inhibited spore germination while 100 μM only transiently inhibited spore germination. This is the first time that self-inhibition of spore germination is demonstrated in P. camemberti. The obtained results provide interesting perspectives for better control of mold-ripened cheese processes.