To investigate the structure-activity relationship of polysaccharide and obtain a better antidepressant polysaccharide, the antidepressant-like activity of a carboxymethyl polysaccharide (C-MEPS2) subjected to submerged fermentation was systematically studied. PC12-H cell and Kunming mice were used to investigate the differences and their mechanism in the antidepressant effects of C-MEPS2 and MEPS2. Cell experiments have showed that C-MEPS2 has a better antidepressant effect than MEPS2. C-MEPS2 could exert antidepressant effects related to catecholamine synthesis with specific sites of TH, D2DR, and P-CAMKII. In addition, C-MEPS2 could repair the Res-induced damage in PC12-H cell, stabilize the mitochondrial membrane potential and regulate intracellular Ca2+ concentration, thus reducing cell apoptosis caused by RES. Antagonists common dosing experiments on animals further proved that CMEPS2 could significantly improve the antidepressant effect of derivatives without affecting the antidepressant mechanism of MEPS2. It is speculated that it may be related to carboxymethylated modification.

Scleroglucan is widely used in the food and chemical industries because of its good rheological property, stability, and emulsification activity. To investigate the influence of different carbon sources on the properties and synthesis of exopolysaccharides (EPS), the three EPSs (GEPS, glucose was used as the carbon source; LEPS, lactose was used as the carbon source; and SEPS, sucrose was used as the carbon source) were determined, respectively. It was found that the yield and viscosity of exopolysaccharides were different. When sucrose and glucose were used as the carbon sources, the viscosity and yield of EPS were both higher than lactose. The scanning electron microscopy (SEM) images showed that the three EPSs had different morphologies, but the monosaccharide analysis showed that they were all composed of glucose units. Fourier transform infrared spectroscopy (FT-IR) proved that there were no additional substituents for the three EPSs. Furthermore, the high performance liquid chromatography (HPLC) results showed that SEPS and LEPS had two fractions. Through the analysis of proteomics data, there were few differences in the metabolic pathways between GEPS and SEPS, but a significant difference between LEPS and SEPS. Our study provides a theoretical basis and reference for understanding the biosynthesis of exopolysaccharides and the development of different types of EPS products.

Monascus vinegar (MV) exerts beneficial effects on cardiovasular diseases. The present work explored the lipid-lowering mechanism of MV and the correlation among gut microbiota, lipid metabolism and inflammation. The results illustrated that the administration of MV ameliorated hyperlipidemia by regulating Peroxisome proliferator-activated α (PPARα)-, Nuclear factor-E2-related factor 2 (Nrf2)- and Nuclear factor κB (NF-κB)-mediated signals and modulating the gut microbiota composition in hyperlipidemia rats. Moreover, Lactobacillus, Roseburia and Lachnostridium showed positive correlation with antioxidative parameters and negative correlation with lipid metabolism and inflammation parameters. Whereas Clostridium, Desulfovibrio and Streptococcus exhibited the opposite effect. Importantly, the differences in lipid-lowering effect between high-dose of MV (HD) group and low acetic acid and lovastatin (LLA) group were evaluated, which indicated that the other components in MV could improve the lipid-lowering effect of acetic acid and lovastatin. Our findings provided a novel insight into the lipid-lowering effect of MV.

The structure and antidepressant like activity of MEPS2 extracted from Marasmius androsaceus subjected to submerged fermentation was systematically studied. MEPS2 is a pyranoid polysaccharide composed of glucose and arabinose, which have a molar ratio of 0.56:0.08. The molecular weight was 85,944 Da. The NMR spectrum suggested the extracted MEPS2 contained uronic acid, and the glucosyl linkage was in α form, in accordance with the analysis of FT-IR spectrum. MEPS2 can considerably enhance the levels of noradrenalin (NE) and dopamine (DA) by ELISA. In addition, western blotting results indicated that MEPS2 can enhance the expression levels of TH, D2DR, and CAMKII. Furthermore, we found that AMPT, raclopride, and prazosin blocked the immobility and time-reducing effect of MEPS2. Overall, the antidepressant-like effect of MEPS2 may be involved in catecholamine synthesis and release, and TH, D2DR and CAMKII play an important role in this process.

The objective of this study is to optimize fermentation conditions for large production of Marasmius androsaceus biomass and metablites production. The desirability function and chemometric methods were applied to optimize the fermentation conditions of M. androsaceus fermentation conditions in a 500 mL shake flask. Based on the desirability function methods, Plackett-Burman (PB) design was employed to optimize fermentation process parameters (culturing temperature, rotating speed, culture time, initial pH, inoculum size, inoculum age and inoculum volume). Culturing temperature, rotating speed were found to significantly impact Da value which were chosen as assessment criteria and were further optimized by Box-Behnken (BB) design. The response surface regression (RSM) and artificial neural network-genetic algorithm (ANN-GA) were employed to analyze the results. Finally, the optimum M. androsaceus submerged fermentation condition in a 500 mL shake flask were obtained as follows: initial pH of 6.0, rotating speed of 169 rpm, culture time 6.57 days, culture temperature 26.7 °C, inoculum size of 5