: Background: The polysaccharides are one of the main active ingredients of Polygonum sibiricum (PSP), which is a traditional food and medicine homologues in China. The antidepressant-like effects of PSP and its underlying mechanisms remain to be studied in depth, especially the regulation of microglial polarization. Methods: The chemical composition and structural characteristics of PSP was determined firstly. The CUMS procedure was carried out to the zebrafish for 5 weeks and PSP were immersed administration for 9 days (1 h/d). The body weight of zebrafish was monitored and the behavioral tests, including the novel tank test and light and dark tank test, were performed to evaluate the antidepressant-like effects of PSP. Then the function of HPI axis, the levels of peripheral inflammation, neuronal and blood-brain barrier damage in mesencephalon and telencephalon and the mRNA expression of M1/M2 phenotype genes in brain were examined. Results: PSP samples had the typical structure characteristics of polysaccharide, consisting of glucose, mannose and galactose with the average Mw 20.48 kDa, which owned a porous and agglomerated morphology. Compared with untreated zebrafish, the depression-like behaviors of CUMS-induced zebrafish were significantly attenuated. PSP significantly decreased the levels of cortisol and the pro-inflammatory cytokines and increased the levels of the anti-inflammatory cytokines in the body of CUMS-induced depressive zebrafish. Furthermore, neuronal and blood-brain barrier damage in mesencephalon and telencephalon and the mRNA expression of M1/M2 phenotype genes in brain were remarkably reversed by PSP. Conclusion: These findings indicated that the antidepressant-like effects of PSP were related to alter the HPI axis hyperactivation, suppress peripheral inflammation, inhibit neuroinflammation induced by microglia hyperactivation, and modulate microglial M1/M2 polarization. The current study provides foundation to the future exploitation of PSP in the functional foods of emotional regulation.

The traditional processing of Dendrobium officinale (DO) is manufactured through five necessary processing steps: fresh strips, drying at 85 °C, curling, molding, and drying at 35 °C (Fengdou), and the antioxidant activity of DO were increased after processing into Fengdou. To comprehensively analyses the changing functional components, a plant-wide target metabolomics were employed. In total, 739 differential ingredients were identified in five processing treatments, mainly highlighting differences in variation with phenolic acids, flavonoids, lipids, and amino acids and their derivatives, and glycosylation of aglycone result in the up-regulation in flavonoid glycosides levels. Temperature is a key step in DO processing production. In addition, the main enrichment of specific differential ingredients was found in five different metabolic pathways, including glucosinolate biosynthesis, linoleic acid metabolism, flavonoid biosynthesis, phenylpropanoid biosynthesis, ubiquinone and other terpene quinone biosynthesis. Correlation analysis clarified that total phenols and flavonoids showed a significant positive correlation with antioxidant capacity. This study provides new insights into the influence of processing processes on DO quality, which may lead to guidance for the high-quality production of DO.

Polygonum sibiricum is a traditional Chinese food and medicine homologues with multiple active ingredients and extensive bioactive effects. Polygonum sibiricum polysaccharides (PSP) are one of the main active ingredients with the antidepressant activity, meanwhile the specific mechanisms of its action are still unclear. Recently, it is recognized by researchers that microglia play a double-edged role in neuroinflammation and the transformation of M1/M2 microglial phenotypes appears to be a potential therapeutic strategy in depression. Therefore, the present study evaluated the effects of PSP on microglial M1/M2 polarization and the molecular mechanisms were studied based on the lipopolysaccharide (LPS)-induced BV2 cell activation model. The results show that PSP significantly inhibited NO and LDH release and reduced ROS levels in LPS-induced BV2 cells. PSP could significantly reduce the protein expression level of Iba-1, decreased the mRNA levels of TNF-, IL-1 and IL-6, increased the mRNA level of IL-10. PSP also significantly reduced the protein expression level of CD16/32 and increased it of CD206, reduced the mRNA level and fluorescence intensity of iNOS and increased them of Arg-1. However, PSP pretreatment reversed the alterations of BDNF/TrkB/CREB and Notch/Hes1 pathways in LPS-induced BV2 cells. These results suggested that PSP exerted the anti-inflammatory effects by inhibiting M1 phenotype polarization and promoting microglia polarization toward M2 phenotype, and its regulation of microglia M1/M2 polarization may be associated with modulating the BDNF/TrkB/CREB and Notch/Hes1 pathways.

The development of a method to produce coumarins unsubstituted on the pyranic nucleus catalyzed from Wells–Dawson heteropolyacid (H₆P₂W₁₈O₆₂), phenol derivatives and ethyl 3,3-diethoxypropionate using Pechmann condensation under solvent-free conditions is described. This catalytic method was also applied successfully to synthesize various substituted coumarins, including the corresponding phenols and ethyl 3,3-diethoxypropionate. This work provides a novel, cheaper and safer way to syhthesize coumarins unsubstituted on the pyranic nucleus.