Identification of galacturonic acid-rich polysaccharide with intestinal immune system modulating activity via Peyer's patch from postbiotics of Phellinus linteus mycelial submerged culture

Extraction, purification, structural features, modifications, bioactivities, structure-activity relationships, and applications of polysaccharides from garlic: A review

Garlic is a common vegetable and spice in people's daily diets, in which garlic polysaccharide (GP) is one of the most important active components with a variety of benefits, such as antioxidant, immune-enhancing, anti-inflammatory, liver-protective and bowel-regulating properties. >20 types of GPs, mainly crude polysaccharides, have been identified. However, the exact chemical composition of GPs or the mechanism underlying their pharmacological activity is still not fully understood. The extraction and purification methods of GPs are compared in this review while providing detailed information on their structural features, identification methods, major biological activities, mechanisms of actions, structural modifications, structure-activity relationships as well as potential applications. Finally, the limitations of GP research and future issues that need to be addressed are discussed in this review. GPs are widely recognized as substances with great potential in the pharmaceutical and food industries. Therefore, this review aims to provide a comprehensive summary of the latest research progresses in the field of GPs, together with scientific insights and a theoretical support for the development of GPs in research and industrialization.

Neuroprotective effects of Rehmannia glutinosa polysaccharide on chronic constant light (CCL)-induced oxidative stress and autophagic cell death via the AKT/mTOR pathway in mouse hippocampus and HT-22 cells

Rehmannia glutinosa polysaccharide (RGP) has been reported to exhibit anti-anxiety effects, yet the underlying mechanism remains unclear. Chronic constant light (CCL) induced cognitive dysfunction associated with oxidative stress in mice has been reported. Here, the neuroprotective effect of RGP on hippocampal neuron damage in CCL-treated mice was investigated. In vivo study, mice were subjected to CCL for 4 weeks and/or oral administration of 100, 200 and 400 mg/kg RGP every other day. In vitro experiment, hippocampal neuron cells (HT-22) was exposed to LED light and/or supplemented with 62.5, 125 and 250 μg/mL RGP. Mice exposed to CCL showed impaired cognitive and depressive-like behavior in the hippocampus, which were reversed by RGP. Meanwhile, RGP reversed light-induced oxidative stress and autophagy both in mice and hippocampal neuron cells (HT-22). Furthermore, compared with Light-exposed group, RGP treatment activated the AKT/mTOR pathway. Importantly, the AKT inhibitor Perifosine significantly weakened the neuroprotective of RGP on Light-induced oxidative stress and autophagy in HT-22 cells by inhibiting AKT/mTOR pathway and increasing the content of autophagy-related protein. Our data demonstrated, for the first time, that oxidative stress and the AKT/mTOR pathway plays a critical role in Light-induced apoptosis and autophagic cell death in mice and HT-22 cells.

Phellinus linteus polysaccharides: A review on their preparation, structure-activity relationships, and drug delivery systems

Phellinus linteus polysaccharides exhibit antitumor, immunomodulatory, anti-inflammatory, and antioxidant properties, mitigate insulin resistance, and enhance the diversity and abundance of gut microbiota. However, the bioactivities of P. linteus polysaccharides vary owing to the complex structure, thereby, limiting their application. Various processing strategies have been employed to modify them for improving the functional properties and yield. Herein, we compare the primary modes of extraction and purification employed to improve the yield and purity, review the structure-activity relationships, and discuss the application of P. linteus polysaccharides using nano-carriers for the encapsulation and delivery of various drugs to improve bioactivity. The limitations and future perspectives are also discussed. Exploring the bioactivity, structure-activity relationship, processing methods, and delivery routes of P. linteus polysaccharides will facilitate the development of functional foods and dietary supplements rich in P. linteus polysaccharides.