Efficacy of Jihwangeumja (Dihuang Yinzi) on cognitive function and activities of daily living in patients with Alzheimer disease: A protocol for a systematic review and meta-analysis

Di-Huang-Yin-Zi regulates P53/SLC7A11 signaling pathway to improve the mechanism of post-stroke depression

ETHNOPHARMACOLOGICAL RELEVANCE

Post-stroke depression (PSD) is a condition characterized by a profoundly depressed mood and diminished interest following a stroke. Di-Huang-Yin-Zi (DHYZ), a traditional Chinese herbal preparation, gained widespread use and shown favorable outcomes in PSD treatment. However, the combination mechanisms of this formula for PSD remain unclear.

AIM OF STUDY

This study aimed to assess the therapeutic effects of DHYZ extract on rats with PSD and further investigate its underlying mechanism.

MATERIALS AND METHODS

The active components of DHYZ extract were quantified by the high-performance liquid chromatography-ultraviolet (HPLC-UV). Neurofunctional and depressive-like behavioral tests were performed to assess the neuroprotective effects of DHYZ extract after establishing a PSD rat model. Brain tissue damage volume was assessed using TTC staining, and transmission electron microscopy (TEM) was used to observe the ultrastructural changes of neurons in the prefrontal cortex region, while cell apoptosis was evaluated through TUNEL assay in the prefrontal cortex region of the brain. The effect of DHYZ on ferroptosis markers includes Fe2+, malondialdehyde (MDA), reactive oxygen species (ROS), and glutathione (GSH) were determined in the brain tissue. Moreover, the expression of key proteins or mRNA levels of the P53/SLC7A11 signaling pathway were detected using Western blot or PCR, respectively. Additionally, P53-constructed overexpression vectors were injected to increase the level of P53. In this series of experiments, ferroptosis markers and key factors of the P53/SLC7A11 signaling pathway were evaluated.

RESULTS

DHYZ extract could increase the sucrose preference of SPT, but decrease the duration of immobility of FST and cortical infarct volume of PSD rats. A TEM study revealed that DHYZ extract improved synaptic ultrastructure in the cortical region of PSD rats. Furthermore, DHYZ treatment effectively decreased ROS and MDA levels, inhibiting the expression of ferroptosis-related markers such as Fe2+, SLC7A11, and GPX4. Additionally, DHYZ promoted the ubiquitination of P53, thus inhibiting its degradation. Notably, AAV-mediated overexpression of P53 reversed the effects of DHYZ on neuroprotection and ferroptosis inhibition in PSD rats.

CONCLUSIONS

Our results demonstrated that DHYZ extract alleviates the symptoms and enhances the functional capability of PSD rats, mainly by suppressing the ferroptosis through the P53/SLC7A11/GPX4 pathway.

Radix Rehmanniae Praeparata (Shu Dihuang) exerts neuroprotective effects on ICV-STZ-induced Alzheimer's disease mice through modulation of INSR/IRS-1/AKT/GSK-3β signaling pathway and intestinal microbiota

Radix Rehmanniae Praeparata (RRP, Shu Dihuang in Cinese) is widely used as primal medicine in Chinese herbal formula for the treatment of Alzheimer's disease (AD). However, the underlying mechanism of RRP for AD remains unclear. The aim of this study was to investigate the therapeutic effect of RRP on intracerebroventricular injection of streptozotocin (ICV-STZ)-induced AD model mice and its potential mechanism. ICV-STZ mice were continuously gavaged with RRP for 21 days. The pharmacological effects of RRP were evaluated by behavioral tests, brain tissue H&E staining and hippocampal tau protein phosphorylation levels. The expression levels of insulin receptor (INSR), IRS-1, pSer473-AKT/AKT and pSer9-GSK-3β/GSK-3β proteins in hippocampal and cortical tissues were detected by Western-blot method. The 16S rRNA gene sequencing was used to analyze the changes of intestinal microbiota in mice. The compounds in RRP were analyzed by mass spectrometry and their binding ability to INSR proteins was detected by molecular docking. The results showed that RRP ameliorated cognitive dysfunction and neuronal pathological changes of brain tissue in ICV-STZ mice, reduced tau protein hyperphosphorylation, INSR, IRS-1, pSer473-AKT/AKT, and pSer9-GSK-3β/GSK-3β levels in hippocampal and cortical tissues. Meanwhile, RRP reversed ICV-STZ-induced dysregulation of intestinal microbiota in AD mice. Mass spectrometry analysis showed that the RRP consisted mainly of seven compounds, namely Acteoside (Verbascoside), 5-Hydroxymethyl-2-furaldehyde (5-HMF), Apigenin7-O-glucuronide, Icariin, Gallic acid, Quercetin-3β-D-glucoside, and Geniposide. Molecular docking results further indicated that the compounds in RRP have binding ability to INSR protein and potential multiple synergistic effects. RRP ameliorates cognitive dysfunction and brain histopathological changes in AD mice. The mechanism of RRP ameliorating AD may be related to the regulation of INSR/IRS-1/AKT/GSK-3β signaling pathway and intestinal microbiota. This study supports the potential anti-AD efficacy of RRP and initially reveals the pharmacological mechanism of RRP, providing a theoretical basis for further clinical application of RRP.

The mechanism of ferroptosis regulating oxidative stress in ischemic stroke and the regulation mechanism of natural pharmacological active components

Cerebrovascular diseases, such as ischemic stroke, pose serious medical challenges worldwide due to their high morbidity and mortality and limitations in clinical treatment strategies. Studies have shown that reactive oxygen species (ROS)-mediated inflammation, excitotoxicity, and programmed cell death of each neurovascular unit during post-stroke hypoxia and reperfusion play an important role in the pathological cascade. Ferroptosis, a programmed cell death characterized by iron-regulated accumulation of lipid peroxidation, is caused by abnormal metabolism of lipids, glutathione (GSH), and iron, and can accelerate acute central nervous system injury. Recent studies have gradually uncovered the pathological process of ferroptosis in the neurovascular unit of acute stroke. Some drugs such as iron chelators, ferrostatin-1 (Fer-1) and liproxstatin-1 (Lip-1) can protect nerves after neurovascular unit injury in acute stroke by inhibiting ferroptosis. In addition, combined with our previous studies on ferroptosis mediated by natural compounds in ischemic stroke, this review summarized the progress in the regulation mechanism of natural chemical components and herbal chemical components on ferroptosis in recent years, in order to provide reference information for future research on ferroptosis and lead compounds for the development of ferroptosis inhibitors.

Neuroprotective effects of Morinda officinalis How.: Anti-inflammatory and antioxidant roles in Alzheimer’s disease

Pharmacological studies have shown that some traditional Chinese medicines (TCMs) have applications in the treatment of Alzheimer’s disease (AD). Morinda officinalis How. (MO) is a TCM with a long history and is widely used to tonify kidney Yang. In vitro and in vivo experiments have suggested that MO contains various effective pharmaceutical components and chemicals, including oligosaccharides, anthraquinones, iridoids, flavonoids, amino acids, and trace elements, conferring MO with anti-inflammatory and antioxidant properties. Neuroinflammation and oxidative stress are undoubtedly hallmarks of neurodegeneration, contributing to AD progression. In this mini-review, we summarize the molecular mechanisms, structure-activity relationships, and potential synergistic and antagonistic effects of active components in MO. This discussion highlights the roles of these active components, such as oligosaccharides, anthraquinones, and iridoid glycosides, in the treatment of AD via anti-inflammatory and antioxidant mechanisms, providing a scientific basis for further utilization of MO.

Dihuang-Yinzi Alleviates Cognition Deficits via Targeting Energy-Related Metabolism in an Alzheimer Mouse Model as Demonstrated by Integration of Metabolomics and Network Pharmacology

Energy metabolism disturbance and the consequent reactive oxygen species (ROS) overproduction play a key and pathogenic role in the onset and progression of Alzheimer’s disease (AD). Dihuang-Yinzi (DHYZ) is a traditional Chinese herbal prescription clinically applied to treat AD and other neurodegenerative diseases for a long time. However, the systematical metabolic mechanism of DHYZ against AD remains largely unclear. Here we aimed to explore the mechanism of DHYZ in the treatment of AD comprehensively in an in vivo metabolic context by performing metabolomics analysis coupled with network pharmacology study and experimental validation. The network pharmacology was applied to dig out the potential target of DHYZ against AD. The metabolomics analysis based on UPLC-HRMS was carried out to profile the urine of 2× Tg-AD mice treated with DHYZ. By integrating network pharmacology and metabolomics, we found DHYZ could ameliorate 4 key energy-related metabolic pathways, including glycerophospholipid metabolism, nicotinate/nicotinamide metabolism, glycolysis, and tricarboxylic acid cycle. Besides, we identified 5 potential anti-AD targets of DHYZ, including DAO, HIF1A, PARP1, ALDH3B2, and ACHE, and 14 key differential metabolites involved in the 4 key energy-related metabolic pathways. Furthermore, DHYZ depressed the mitochondrial dysfunction and the resultant ROS overproduction through ameliorating glycerophospholipid metabolism disturbance. Thereby DHYZ increased nicotinamide adenine dinucleotide (NAD⁺) content and promoted glycolysis and tricarboxylic acid (TCA) cycle, and consequently improved oxidative phosphorylation and energy metabolism. In the present study, we provided a novel, comprehensive and systematic insight into investigating the therapeutic efficacy of DHYZ against AD via ameliorating energy-related metabolism.