Depressive-like behaviors is one of the most prevalent non-motor symptoms in Parkinson's disease (PD), severely compromising patients' quality of life. Dihydromyricetin (DHM), a natural flavonoid, exhibits neuroprotective effects, but its ability to ameliorate PD-related depressive-like behaviors and the underlying mechanisms remain unclear. This study aimed to investigate DHM's mechanism for improving depressive-like behaviors in PD and identify its key molecular targets.

Thirty-two 7 weeks old male C57 BL/6J mice (weighting 24.5±1.5 g) were randomly divided into 4 groups (n=8): Control, PD model, PD+Madopar (positive control), and PD+DHM. Except the control group, all groups received intraperitoneal 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to establish subacute PD models. Motor function was assessed via rotarod, pole and wire hang tests; depressive-like behaviors were evaluated using the open field, forced swimming, and tail suspension tests. Network pharmacology, dataset mining, and molecular docking predicted DHM's key targets for PD treatment. Western blotting and immunofluorescence detected DHM's effects on synaptic plasticity, astrocyte polarization, and ferroptosis. Conditioned medium experiments further validated the predicted mechanisms.

Compared with the PD group, PD+DHM mice showed significantly prolonged rotarod duration and suspension time (P<0.001), reduced pole descent time (P=0.0055), increased total distance (P<0.001) and velocity (P<0.001) in open field test, with higher central activity distance/time ratios (P<0.01), and shorter immobility times in forced swimming and suspension tests (P<0.01). Network pharmacology and molecular docking identified the Lipocalin-2 (LCN2)/NOD-like receptor thermal protein domain associcated protein 3 (NLRP3) axis as DHM's potential target. DHM intervention reversed neuronal loss and Nissl body reduction while upregulating synaptic plasticity markers BDNF, SYN1 and PSD95, compared with the PD group (P<0.01). DHM significantly downregulated LCN2, NLRP3, and A1-astrocyte marker complement component 3 (C3; P<0.001), but upregulated A2-marker S100 calcium binding protein A10(S100A10; P<0.01). Compared with the PD gruop, immunofluorescence revealed reduced GFAP/C3-positive cells and increased GFAP/S100A10 cells in the prefrontal cortex of PD+DHM group (P<0.05). Additionally, DHM decreased acyl-CoA synthetase long chain family member 4 (ACSL4) and Transferrin receptor (TFRC) expression (P<0.001), while increasing GPX4 and SLC7A11 levels (P<0.001) in the prefrontal cortex. Conditioned medium experiments confirmed that DHM and NLRP3 inhibitor MCC950 reversed abnormal ferroptosis-related changes in dopaminergic neurons (P<0.01).

DHM may ameliorate depressive-like behaviors in PD mice by inhibiting the LCN2/NLRP3 axis which promotes A2-astrocyte polarization, mitigates imbalance in astrocyte polarization and alleviates neuronal ferroptosis.

To investigate the potential mechanism by which dihydromyricetin (DHM) ameliorates diabetic nephropathy (DN), and to screen and validate its possible key molecular targets.

A DN model was established using db/db mice, and 100 mg/(kg·d) DHM was administered via gavage 5 d per week for totally 10 weeks. Renal morphological changes were observed after staining to evaluate the effects of DHM. GSE161885 and GSE270526 datasets were obtained from the Gene Expression Omnibus (GEO) database and analyzed in combination with the GeneCards database to screen for DN-related differentially expressed genes (DEGs). Protein-protein interaction (PPI) network and molecular docking were employed to predict potential DHM targets. Western blotting and immunofluorescence staining were performed to detect the effects of DHM on pyroptosis-related pathways in the renal tissues of db/db mice and in high glucose (HG)-induced human renal tubular epithelial cells (HK-2). The specific NLR family pyrin domain containing protein 3 (NLRP3) inhibitor MCC950 was also used to validate the predicted mechanism.

In vivo experiments showed that DHM significantly ameliorated renal pathological damage in db/db mice, alleviated glomerular hypertrophy and mesangial expansion, and markedly reduced Paller scores (P<0.001). Immunofluorescence staining revealed significantly weakened fluorescence signals for α-smooth muscle actin (α-SMA), fibronectin, and collagen Ⅰ in renal tissues. Western blot results showed that the expression levels of collagen Ⅰ, collagen Ⅲ, α-SMA, and transforming growth factor beta 1 (TGF-β1) were significantly decreased (P<0.05). A total of 16 DN-related DEGs were identified. Enrichment analysis revealed that these genes were primarily enriched in pathways such as viral protein interactions, cytokine-cytokine receptor interaction, and the AGE-RAGE signaling pathway in diabetic complications, and were primarily involved in gene functions such as the positive regulation of lymphocyte-mediated immunity, positive regulation of adaptive immune response, and chemokine activity. Molecular docking confirmed NLRP3 as a potential target of DHM. In vivo validation showed that DHM significantly down-regulated gasdermin-D (GSDMD) fluorescence signals and inhibited the expression of pyroptosis-related proteins including NLRP3, Caspase 1, Cleaved-Caspase 1, interleukin 18 (IL-18), and GSDMD (P<0.05). In vitro studies further confirmed that both DHM and the specific NLRP3 inhibitor MCC950 alleviate high glucose-induced fibrosis and pyroptosis in HIC-2 cells.

DHM can ameliorate the progression of DN, and its mechanism is related to inhibiting NLRP3 inflammasome-mediated pyroptosis, thereby alleviating renal inflammation and fibrosis.