Effects of polysaccharides from Gastrodia elata on the immunomodulatory activity and gut microbiota regulation in cyclophosphamide-treated mice

Digestive characteristics of Gastrodia elata Blume polysaccharide and related impacts on human gut microbiota in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Gastrodia elata Blume is a traditional Chinese medicine with the effects of improving the deficiency of the body and maintaining health, and polysaccharide (GEP) is one of the effective ingredients to play these activities of G. elata. Traditionally, G. elata is orally administered, so the activities of GEP are associated with digestive and intestinal metabolism. However, the digestive behavior of GEP and its effects on the human gut microbiota are unclear and need to be fully studied.

AIM OF THE STUDY

This study aimed to investigate the changes in structural characteristics of GEP during digestion and the related impacts of its digestive product on gut microbiota in human fecal fermentation, and to explain the beneficial mechanism of GEP on human health from the perspective of digestive characteristics and "gut" axis.

MATERIALS AND METHODS

The changes of reducing sugars, free monosaccharides and physicochemical properties of GEP during digestion were investigated by GPC, HPLC, FT-IR, CD, NMR, SEM, and TGA. Moreover, polysaccharide consumption, pH value changes, SCFAs production, and changes in gut microbiota during fermentation were also discussed.

RESULTS

During digestion of GEP, glucose was partially released causing a decrease in molecular weight, and a change in monosaccharide composition. In addition, the characteristics of GEP before and after digestion, including configuration, morphology, and stability, were different. The digestive product of GEP was polysaccharide (GEP-I), which actively participated in the fecal fermentation process. As the fermentation time increased, the utilization of GEP-I by the microbiota gradually increased. The abundance of probiotics such as Bifidobacterium, Collinsella, Prevotella, and Faecalibacterium was significantly increased, and the abundance of pathogenic Shigella, Dorea, Desulfovibrio, and Blautia was significantly inhibited, thereby suggesting that GEP has the potential to maintain human health through the "gut" axis. In addition, the beneficial health effects of GEP-I have also been observed in the influence of microbial metabolites. During the fermentation of GEP-I, the pH value gradually decreased, and the contents of beneficial metabolites such as acetic acid, propionic acid, and caproic acid significantly increased.

CONCLUSION

The structure of GEP changed significantly during digestion, and its digestive product had the potential to maintain human health by regulating gut microbiota, which may be one of the active mechanisms of GEP.

Achyranthes bidentata polysaccharides improve cyclophosphamide-induced adverse reactions by regulating the balance of cytokines in helper T cells

The manuscript aimed to study the immune function maintenance effect of Achyranthes bidentata polysaccharides (ABPs). The mice were divided into the control group, cyclophosphamide-induced (CTX) group, and ABPs-treated (ABP) group. The results showed that, compared with the CTX group, ABPs could significantly improve the spleen index and alleviate the pathological changes in immune organs. Ex vivo study of whole spleen cells, the levels of interleukin-2 (IL-2), interleukin-6 (IL-6), interferon-γ (IFN-γ), and tumor necrosis factor-α (TNF-α) were increased. The proliferation of lymphocytes and the proportion of CD3+CD4+ Th cells in peripheral blood mononuclear cells were increased. The transcription of GATA-3, Foxp3, and ROR γ t were decreased, while the transcription of T-bet was increased. The transcriptome sequencing analysis showed that the differentially expressed genes (DEGs) caused by ABPs-treated were mostly downregulated in CTX-induced mice. The Th2-related genes were significantly enriched in DEGs, with representative genes, including Il4, II13, Il9, etc., while increasing the expression of immune effector genes simultaneously, including Ccl3, Ccr5, and Il12rb2. It was suggested that ABPs possibly regulated the balance of cytokines in helper T cells to ameliorate the immune function of CTX-induced mice.

Gastrodia elata polysaccharide alleviates Parkinson's disease via inhibiting apoptotic and inflammatory signaling pathways and modulating the gut microbiota

Parkinson's disease (PD) is a common, chronic, and progressive degenerative disease of the central nervous system for which there is no effective treatment. Gastrodia elata is a well-known food and medicine homologous resource with neuroprotective potential. Gastrodia elata polysaccharide (GEP), which is a highly active and safe component in Gastrodia elata, is an important ingredient in the development of functional products. In this study, GEP was administered to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mice over 3 weeks to investigate its neuroprotective effects. The results showed that GEP significantly alleviated the motor dysfunction of PD mice, inhibited the accumulation of α-synuclein, and reduced the loss of dopaminergic neurons in the brain. Moreover, GEP increased the Bcl-2/Bax ratio and decreased the cleaved-caspase-3 level, suggesting that GEP may ameliorate PD by preventing MPTP-induced mitochondrial apoptosis. GEP also significantly inhibited the increase of GFAP and decreased the levels of TNF-α, IL-1β, and IL-6 in the brain of PD mice, which may be the result of the inhibition of neuroinflammation by the inactivation of the TLR4/NF-κB pathway. Furthermore, the neuroprotective effects of GEP involve the gut-brain axis, as it has been shown that GEP regulated the dysbiosis of PD-related gut microbiota such as Akkermansia, Lactobacillus, Bacteroides, Prevotella, and Faecalibacterium, increased the content of microbial metabolites SCFAs in the colon and increased the level of occludin that repairs the intestinal barrier of PD mice. In conclusion, this study is expected to provide a theoretical basis for the development and application of functional products with GEP from the perspective of neuroprotective effects.

The molecular mechanism of polysaccharides in combating major depressive disorder: A comprehensive review

Major depressive disorder (MDD) is a complex psychiatric condition with diverse etiological factors. Typical pathological features include decreased cerebral cortex, subcortical structures, and grey matter volumes, as well as monoamine transmitter dysregulation. Although medications exist to treat MDD, unmet needs persist due to limited efficacy, induced side effects, and relapse upon drug withdrawal. Polysaccharides offer promising new therapies for MDD, demonstrating antidepressant effects with minimal side effects and multiple targets. These include neurotransmitter, neurotrophin, neuroinflammation, hypothalamic-pituitary-adrenal axis, mitochondrial function, oxidative stress, and intestinal flora regulation. This review explores the latest advancements in understanding the pharmacological actions and mechanisms of polysaccharides in treating major depression. We discuss the impact of polysaccharides' diverse structures and properties on their pharmacological actions, aiming to inspire new research directions and facilitate the discovery of novel anti-depressive drugs.

Supplementation of Lactobacillus plantarum ATCC14917 mitigates non-alcoholic fatty liver disease in high-fat-diet-fed rats

Atherosclerosis and non-alcoholic fatty liver disease (NAFLD) have been increasing at an alarming rate worldwide. Many clinical studies have underlined the link between NAFLD and atherosclerosis. Our previous experiments have discovered that Lactobacillus (L.) plantarum ATCC14917 supplementation could decrease the progression of atherosclerotic lesion formation. In this study, we aimed to investigate the role of supplementation of L. plantarum ATCC14917 mitigates liver injury in rats fed with a high-fat diet (HFD, 45% kcal from fat). A total of 32 rats were randomly divided into four groups, including two intervention groups, who fed with HFD and administering either 1 × 10⁷ or 1 × 10⁹ colony forming units (CFU) of L. plantarum ATCC14917, the normal control group, and the HFD control group. The results showed that supplementation with low-dose and high-dose of L. plantarum ATCC14917 for 8 weeks could alleviate the body weight gain (p < 0.05), hepatic steatosis, and serum lipid metabolism (p < 0.05) in HFD-fed rats. Moreover, supplementation of L. plantarum ATCC 14917 decreased total cholesterol (TC), triglyceride (TG), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels (p < 0.05) in serum, and improved HFD-associated inflammation (p < 0.05). Furthermore, cecal contents were analyzed by high-throughput 16S ribosomal RNA sequencing. The results indicated that supplementation of L. plantarum ATCC 14917 could ameliorate HFD-induced gut dysbiosis. In summary, our findings suggest that supplementation of L. plantarum ATCC 14917 could mitigate NAFLD in rats, suggesting it may be considered as a probiotic agent for preventing HFD-induced obesity.