Alzheimer’s disease (AD) is a common neurological disease with recognition ability loss symptoms and a major contributor to dementia cases worldwide. Gastrodia elata Bl. (GE), a food of medicine–food homology, has been reported to have a mitigating effect on memory and learning ability decline. However, the effect of GE fermented by Lactobacillus plantarum, Acetobacter pasteurianus, and Saccharomyces (FGE) on alleviating cognitive deficits in AD was not studied. Mice were randomly divided into six groups, control, model, donepezil, low, medium, and high doses of FGE, and D-Galactose/Aluminum chloride (D-Gal/AlCl₃) was used to establish an AD-like mouse model. The results indicated that FGE could improve the production of neurotransmitters and relieve oxidative stress damage in AD-like mice, which was evidenced by the declined levels of amyloid-β (Aβ), Tau, P-Tau, acetylcholinesterase (AchE), and malondialdehyde (MDA), and increased acetylcholine (Ach), choline acetyltransferase (ChAT), and superoxide dismutase (SOD) levels in brain tissue. Notably, FGE could enhance the richness of the gut microbiota, especially for beneficial bacteria such as Lachnospira and Lactobacillus. Non-target metabolomics results indicated that FGE could affect neurotransmitter levels by regulating amino acid metabolic pathways to improve AD symptoms. The FGE possessed an ameliorative effect on AD by regulating neurotransmitters, oxidative stress levels, and gut microbiota and could be considered a good candidate for ameliorating AD.

Kaji-ichigoside F1 (KF1), a natural oleanane-type triterpenoid saponin, is the main active constituent from Rosa roxburghii. In the southwest regions of China, particularly in Guizhou Province, this plant was used as a Miao ethnic medicine to prevent and treat dyspepsia, dysentery, hypoimmunity, and neurasthenia. In the present study, the neuroprotective effect of KF1 was evaluated against N-methyl-D-aspartate (NMDA)-induced neurotoxicity in vivo and in vitro. An NMDA-induced PC12 cell neurotoxicity assay showed that KF1 effectively improved cellular viability, inhibited the release of lactate dehydrogenase (LDH), and reduced cell apoptosis. Furthermore, KF1-treated NMDA-induced excitotoxicity mice displayed a remarkable capacity for improving spatial learning memory in the Y-maze and Morris water maze tests. In addition, KF1 increased the levels of the neurotransmitters 5-hydroxytryptamine, dopamine, and monoamine oxidase and reduced the calcium ion concentration in the hippocampus of mice. Hematoxylin and eosin and Nissl staining indicated that KF1 effectively reduced the impairment of neurons. Furthermore, Western blot assays showed that KF1 decreased NMDAR1 expression. In contrast, the NMDAR2B (NR2B), glutamate receptor (AMPA), TrkB, protein kinase B (AKT), mammalian target of rapamycin (mTOR), PSD95, and synapsin 1 were upregulated in NMDA-induced PC12 cells and an animal model. These results suggest that KF1 has a remarkable protective effect against NMDA-induced neurotoxicity, which is directly related to the regulation of the NMDA receptor and the activation of the α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor (AMPAR) and BDNF/AKT/mTOR signaling pathways.

The occurrence of type 2 diabetes mellitus (T2DM), a worldwide chronic disease, is mainly caused by insufficient insulin production and places a huge burden on the health system. Gastrodia elata Blume (GE), a food of medicine–food homology, has been reported to have the ability to inhibit glycosidase activity, indicating its potential in the treatment of diabetes. However, the main pharmacological components of GE for the treatment of T2DM have not been fully clarified. Therefore, this study aims to clarify the pharmacological components changes of GE with different drying methods and the treatment of T2DM using HPLC, network pharmacology, molecular docking and experimental evaluations. The results showed that the GE samples processed by the steam-lyophilized method possessed the highest total content of the six marker components and the strongest antioxidant and α-glucosidase inhibitory abilities. Meanwhile, the six marker compounds had a total of 238 T2DM-related gene targets. Notably, these active compounds have good affinity for key gene targets associated with T2DM signaling pathways. In conclusion, this study revealed that different drying methods of GE affect the content of its major active compounds, antioxidant capacity, α-glucosidase inhibitory capacity and potential pharmacological effects on T2DM, indicating that it is a potential treatment of T2DM.