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This study attempted to access the neuroprotective effect of diosgenin on the senescent mice induced by d-galactose (D-gal). The mice in the experiments were orally administered with diosgenin (1, 5, 25 and 125 mg/kg), for four weeks from the sixth week. The learning and memory abilities of the mice in Morris water maze test and the mechanism involved in the neuroprotective effect of diosgenin on the mice brain tissue were investigated.

Diosgenin (5, 25 and 125 mg/kg, p.o.) showed significantly improved learning and memory abilities in Morris water maze test compared to D-gal treated mice (200 mg/kg, ten weeks). Diosgenin also increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and decreased the malondialdehyde (MDA) level in the brain of D-gal treated mice.

These results indicated that diosgenin has the potential to be a useful treatment for cognitive impairment. In addition, the memory enhancing effect of diosgenin may be partly mediated via enhancing endogenous antioxidant enzymatic activities.

The purpose of this study was to evaluate the effects of diosgenin on the D-galactose-induced cerebral cortical widely dispersed apoptosis. Male 12-week-old Wistar rats were divided into four groups: Control (1mg/kg/day of saline, i.p.), DD0 (150mg/kg/day of D-galactose, i.p.), DD10, and DD50 (D-galactose$+10$ or 50mg/kg/day of diosgenin orally). After eight weeks, histopathological analysis, positive TUNEL and Western blotting assays were performed on the excised cerebral cortex from all four groups. The TUNEL-positive apoptotic cells, the components of Fas pathway (Fas, FADD, active caspase-8 and active caspase-3), and mitochondria pathway (t-Bid, Bax, cytochrome $c$, active caspase-9 and active caspase-3) were increased in the DD0 group compared with the control group, whereas they were decreased in the DD50 group. The components of survival pathway (p-Bad, Bcl-2, Bcl-xL, IGF-1, p-PI3K and p-AKT) were increased in the DD50 group compared to the control group, whereas the levels of Bcl-xL, p-PI3K, and p-AKT were also compensatorily increased in the DD0 group compared to the control group. Taken together, diosgenin suppressed D-galactose-induced neuronal Fas-dependent and mitochondria-dependent apoptotic pathways and enhanced the Bcl-2 family associated pro-survival and IGF-1-PI3K-AKT survival pathways, which might provide neuroprotective effects of diosgenin for prevention of the D-galactose-induced aging brain.

Cardiovascular diseases in post-menopausal women are on a rise. Oxidative stress is the main contributing factor to the etiology and pathogenesis of cardiovascular diseases. Diosgenin, a member of steroidal sapogenin, is structurally similar to estrogen and has been shown to have antioxidant effects. Therefore, we aimed to investigate the effects of diosgenin in preventing oxidation-induced cardiomyocyte apoptosis and assessed its potential as a substitute substance for estrogen in post-menopausal women. Apoptotic pathways and mitochondrial membrane potential were measured in H9c2 cardiomyoblast cells and neonatal cardiomyocytes treated with diosgenin for 1h prior to hydrogen peroxide (H₂O₂) stimulation. H₂O₂-stimulated H9c2 cardiomyoblast cells displayed cytotoxicity and apoptosis via the activation of both Fas-dependent and mitochondria-dependent pathways. Additionally, it led to the instability of the mitochondrial membrane potential. However, the H₂O₂-induced H9c2 cell apoptosis was rescued by diosgenin through IGF1 survival pathway activation. This led to the recovery of the mitochondrial membrane potential by suppressing the Fas-dependent and mitochondria-dependent apoptosis. Diosgenin also inhibited H₂O₂-induced cytotoxicity and apoptosis through the estrogen receptor interaction with PI3K/Akt and extracellular regulated protein kinases 1/2 activation in myocardial cells. In this study, we confirmed that diosgenin attenuated H₂O₂-induced cytotoxicity and apoptosis through estrogen receptors-activated phosphorylation of PI3K/Akt and ERK signaling pathways in myocardial cells via estrogen receptor interaction. All results suggest that H₂O₂-induced myocardial damage is reduced by diosgenin due to its interaction with estrogen receptors to decrease the damage. Herein, we conclude that diosgenin might be a potential substitute substance for estrogen in post-menopausal women to prevent heart diseases.

Wilson’s disease (WD) is a hereditary condition marked by abnormalities in copper metabolism, which precipitate a spectrum of neurological symptoms and cognitive impairments. Emerging research has highlighted ferroptosis (FPT) as a distinct type of programmed cell death, potentially linked to various cognitive dysfunctions. Nevertheless, the connection between FPT and cognitive impairment in Wilson’s disease (WDCI) remains largely enigmatic. In our study, we utilized a multifaceted approach, combining reverse network pharmacology, data mining, and molecular docking techniques to explore the potential for treating WDCI via FPT-related pathways. This thorough analysis revealed a series of proteins, including P38$\alpha$, GSK3$\beta$, P53, GPX4, and PTGS2, as pivotal targets for WDCI treatment. Notably, Diosgenin (DG) has been identified as a prospective core component in this therapeutic framework. In the WD copper-loaded rat model, evaluations using the Morris water maze (MWM), Y maze, hematoxylin and eosin staining, transmission electron microscopy (TEM), and immunofluorescence (IF) detection showed that DG significantly enhanced cognitive function recovery, reduced structural damage to hippocampal neurons, and protected mitochondrial integrity. In addition, Western blot (WB) and quantitative reverse transcription PCR (qRT-PCR) analysis showed that DG significantly upregulated the expression levels of proteins and mRNA such as P38$\alpha$, GSK3$\beta$, P53, GPX4, and PTGS2 in animal and cell models. Furthermore, DG effectively reversed the dysregulated expression of oxidative stress markers, including ${\text{Fe}}^{2+}$, malondialdehyde (MDA), superoxide dismutase (SOD), and reactive oxygen species (ROS). This study elucidates the neuroprotective effect of DG on hippocampal neurons by activating the P38$\alpha$-mediated FPT pathway, highlighting its efficacy as a potent monomer in traditional Chinese medicine and illuminating its potential role in the clinical treatment of WDCI.