Alpinia oxyphylla-Schisandra chinensis Herb Pair Alleviates Amyloid-β Induced Cognitive Deficits via PI3K/Akt/Gsk-3β/CREB Pathway

Signaling pathways in the treatment of Alzheimer's disease with acupuncture: a narrative review

BACKGROUND

To date, there is no effective treatment for Alzheimer's disease (AD), a progressive neurodegenerative disorder that is increasing in prevalence worldwide. The objective of this review was to summarize the core targets and signaling pathways involved in acupuncture treatment for AD.

METHODS

We reviewed numerous signaling pathways, including mammalian target of rapamycin (mTOR), phosphatidylinositol 3-kinase-protein kinase B (PI3 K/Akt), adenosine monophosphate-activated protein kinase (AMPK), mitogen-activated protein kinase (MAPK), nuclear factor (NF)-kB, p53, Wnt, nitric oxide (NO), Janus kinase / signal transducer and activator of transcription (JAK/ STAT), RhoA/ROCK (Rho-associated protein kinase) and Ca2+/ calmodulin-dependent protein kinase II (CaMKII) / cyclic adenosine monophosphate-response element-binding protein (CREB). The relevant data were obtained from PubMed, EMBASE, Web of Science, China National Knowledge Infrastructure (CNKI) and Wanfang databases.

RESULTS

In summary, the effects of acupuncture are mediated by multiple targets and pathways. Furthermore, acupuncture can improve pathological changes associated with AD (such as abnormal deposition of amyloid (A)β, tau hyperphosphorylation, synaptic dysfunction and neuronal apoptosis) through multiple signaling pathways.

CONCLUSION

Overall, our findings provide a basis for future research into the effects of acupuncture on AD.

Pharmacokinetic study and neuropharmacological effects of atractylenolide Ⅲ to improve cognitive impairment via PI3K/AKT/GSK3β pathway in intracerebroventricular-streptozotocin rats

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional Chinese herbal remedy Atractylodes macrocephala Koidz is renowned for its purported gastrointestinal regulatory properties and immune-enhancing capabilities. Atractylenolide III (ATL III), a prominent bioactive compound in Atractylodes macrocephala Koidz, has demonstrated significant pharmacological activities. However, its impact on neuroinflammation, oxidative stress, and therapeutic potential concerning Alzheimer's disease (AD) remain inadequately investigated.

AIM OF THE STUDY

This study aims to assess the plasma pharmacokinetics of ATL III in Sprague-Dawley (SD) rats and elucidate its neuropharmacological effects on AD via the PI3K/AKT/GSK3β pathway. Through this research, we endeavor to furnish experimental substantiation for the advancement of novel therapeutics centered on ATL III.

MATERIALS AND METHODS

The pharmacokinetic profile of ATL III in SD rat plasma was analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). AD models were induced in SD rats through bilateral intracerebroventricular (ICV) administration of streptozotocin (STZ). ATL III was administered at doses of 0.6 mg/kg, 1.2 mg/kg, and 2.4 mg/kg, while donepezil (1 mg/kg) served as control. Cognitive function assessments were conducted employing behavioral tests including the Morris Water Maze and Novel Object Recognition. Neuronal pathology and histological changes were evaluated through Nissl staining and Hematoxylin-Eosin (HE) staining, respectively. Oxidative stress levels were determined by quantifying malondialdehyde (MDA) content and total superoxide dismutase (T-SOD) activity. Molecular docking analysis was employed to explore the direct binding between ATL III and its relevant targets, followed by validation using Western blot (WB) experiments to assess the expression of p-Tau, PI3K, AKT, GSK3β, and their phosphorylated forms.

RESULTS

Within the concentration range of 5-500 ng/mL, ATL III demonstrated exceptional linearity (R2 = 0.9991), with a quantification limit of 5 ng/mL. In male SD rats, ATL III exhibited a Tmax of 45 min, a t1/2 of 172.1 min, a Cmax of 1211 ng/L, and an AUC(0-t) of 156031 ng/L*min. Treatment with ATL III significantly attenuated Tau hyperphosphorylation in intracerebroventricular-streptozotocin (ICV-STZ) rats. Furthermore, ATL III administration mitigated neuroinflammation and oxidative stress, as evidenced by reduced Nissl body loss, alleviated histological alterations, decreased MDA content, and enhanced T-SOD activity. Molecular docking analyses revealed strong binding affinity between ATL III and the target genes PI3K, AKT, and GSK3β. Experimental validation corroborated that ATL III stimulated the phosphorylation of PI3K and AKT while reducing the phosphorylation of GSK3β.

CONCLUSIONS

Our results indicate that ATL III can mitigate Tau protein phosphorylation through modulation of the PI3K/AKT/GSK3β pathway. This attenuation consequently ameliorates neuroinflammation and oxidative stress, leading to enhanced learning and memory abilities in ICV-STZ rats.

Dendrobium nobile Lindl. alkaloid decreases Tau hyperphosphorylation via regulating PI3K/Akt/GSK-3β pathway in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANT

Dendrobium is a traditional and precious Chinese medicinal herb. The Compendium of Materia Medica describes its effects as "benefiting intelligence and dispelling shock, lightning the body and extending life". Dendrobium nobile Lindl. is a precious variety of Dendrobium. Our previous data showed Dendrobium nobile Lindl. alkaloid (DNLA) has significant neuroprotective effects and can improve cognitive dysfunction. However, the specific effects and mechanisms of action of its main active component, DNLA, on cognitive dysfunction caused by Tau hyperphosphorylation, are still unclear.

AIM OF THE RESEARCH

This study aimed to determine the effects of DNLA on phosphatidylinositol-3 kinase (PI3K)/protein kinase B (Akt)/glycogen synthase kinase 3β (GSK-3β) pathway, thus to explore the mechanisms of DNLA to inhibit Tau hyperphosphorylation.

MATERIALS AND METHODS

We used wortmannin (WM) and GF-109203X (GFX)-induced hyperphosphorylation of Tau in N2a cells and rats to detect the protective mechanism of DNLA in vivo and in vitro. In vitro, the effect of modeling method on Tau hyperphosphorylation was screened and verified by Western Blotting (WB), and the regulation of Tau hyperphosphorylation and PI3K/Akt/GSK-3β pathway by different concentrations of DNLA was detected by WB. In vivo, MWM was used to detect the effect of DNLA on model rats, and then Nissl staining was used to detect the loss of neurons. Finally, WB was used to detect the regulation of Tau hyperphosphorylation and PI3K/Akt/GSK-3β pathway by different concentrations of DNLA.

RESULTS

DNLA could rescue the abnormal PI3K/Akt/GSK-3β pathway and reverse the hyperphosphorylation of Tau induced by WM and GFX in N2a cells. Furthermore, DNLA improved the learning and memory of WM and GFX-induced model rats. Moreover, DNLA regulated PI3K/Akt/GSK-3β pathway and reduced the p-Tau and neuronal damage in the hippocampus of model rats.

CONCLUSION

DNLA may be a promising candidate for reducing hyperphosphorylation of Tau.

Combination of Alpinia Oxyphylla Fructus and Schisandra Chinensis Fructus ameliorates aluminum-induced Alzheimer's disease via reducing BACE1 expression

Being the most common form of dementia, Alzheimer's disease (AD) has a series of modifiable risk factors, including metal ions represented by aluminium. Aluminium (Al) exhibits its neurotoxic effects, especially mainly by affecting amyloid-β protein (Aβ) aggregation and Tau hyperphosphorylation. As reported in our previous study, the combination of Alpinia Oxyphylla Fructus and Schisandra Chinensis Fructus (AS) had a neuroprotective effect. This study aimed to evaluate the anti-AD effect of AS and the mechanism by which AS reduces the neurotoxic effect of Al. Firstly, we used aluminium-maltol (Al(mal)₃) to construct a mouse model of AD and performed oral administration of AS, followed by behavioral experiments, and we collected the mouse brain for immunohistochemistry analysis. In vivo results showed that AS significantly improved Al-induced cognitive decline in mice, and reduced the levels of Aβ_1-42 and P-Tau in the brain, which further proved the anti-AD effect of AS. Then, in order to explore the mechanism by which AS reduced Aβ_1-42, Al-induced PC12 cells were used for the in vitro experiments. Compared with other ratios, the ratio of Alpinia Oxyphylla Fructus: Schisandra Chinensis Fructus (AO:SC) = 1:2 could better improve the cell viability and reduce the Aβ_1-42 level. According to western blot and quantitative real-time polymerase chain reaction (qPCR) results, AS ameliorated the pathological process by downregulating the expression of β-secretase (BACE1), rather than by reducing the expression of amyloid precursor protein (APP) or Tau. These results suggest that AS ameliorated Al-induced AD by affecting the expression of BACE1 and reducing the level of Aβ_1-42, thereby exerting a neuroprotective effect. Combined with previous studies, this study shows that AS has potential for further research and development in AD treatment.

Biological Activities, Pharmacokinetics and Toxicity of Nootkatone: A Review

Abstract:

Plant-based drugs have a significant impact on modern therapeutics due to their vast array of pharmacological activities. The integration of herbal plants in the current healthcare system has emerged as a new field of research. It can be used for the identification of novel lead compound candidates for future drug development. Nootkatone is a sesquiterpene derivative and an isolate of grapefruit. Shreds of evidence illustrate that nootkatone targets few molecular mechanisms to exhibit its pharmacological activity and yet needs more exploration to be established. The current review is related to nootkatone, drafted through a literature search using research articles and books from different sources, including Science Direct, Google Scholar, Elsevier, PubMed, and Scopus. It has been reported to possess a wide range of pharmacological activities such as anti-inflammatory, anticancer, antibacterial, hepatoprotective, neuroprotective, and cardioprotective. Although preclinical studies in experimental animal models suggest that nootkatone has therapeutic potential, it is further warranted to evaluate its toxicity and pharmacokinetic parameters before being applied to humans. Hence in the present review, we have summarized the scientific knowledge on nootkatone with a particular emphasis on its pharmacological properties to encourage researchers for further exploration in preclinical and clinical settings.