Effect of Ginkgo biloba Extract EGb761 on Hippocampal Neuronal Injury and Carbonyl Stress of D-Gal-Induced Aging Rats

Aluminum chloride and D-galactose induced a zebrafish model of Alzheimer's disease with cognitive deficits and aging

Alzheimer's disease (AD) is an age-related neurodegenerative disorder. Transgenic and pharmacological AD models are extensively studied to understand AD mechanisms and drug discovery. However, they are time-consuming and relatively costly, which hinders the discovery of potential anti-AD therapeutics. Here, we established a new model of AD in larval zebrafish by co-treatment with aluminum chloride (AlCl3) and D-galactose (D-gal) for 72 h. In particular, exposure to 150 μM AlCl3 + 40 mg/mL D-gal, 200 μM AlCl3 + 30 mg/mL D-gal, or 200 μM AlCl3 + 40 mg/mL D-gal successfully induced AD-like symptoms and aging features. Co-treatment with AlCl3 and D-gal caused significant learning and memory deficits, as well as impaired response ability and locomotor capacity in the plus-maze and light/dark test. Moreover, increased acetylcholinesterase and β-galactosidase activities, β-amyloid 1-42 deposition, reduced telomerase activity, elevated interleukin 1 beta mRNA expression, and enhanced reactive oxygen species production were also observed. In conclusion, our zebrafish model is simple, rapid, effective and affordable, incorporating key features of AD and aging, thus may become a unique and powerful tool for high-throughput screening of anti-AD compounds in vivo.

Whole Plant Extracts for Neurocognitive Disorders: A Narrative Review of Neuropsychological and Preclinical Studies

The incidence of neurodegenerative disorders like Alzheimer's or Parkinson's Disease, characterized by a progressive cognitive decline, is rising worldwide. Despite the considerable efforts to unveil the neuropsychological bases of these diseases, there is still an unmet medical need for effective therapies against cognitive deficits. In recent years, increasing laboratory evidence indicates the potential of phytotherapy as an integrative aid to improve cognitive functions. In this review, we describe the data of plant whole extracts or single compounds' efficacy on validated preclinical models and neuropsychological tests, aiming to correlate brain mechanisms underlying rodent behavioral responses to human findings. After a search of the literature, the overview was limited to the following plants: Dioscorea batatas, Ginkgo biloba, Melissa officinalis, Nigella sativa, Olea europaea, Panax ginseng, Punica granatum, and Vitis vinifera. Results showed significant improvements in different cognitive functions, such as learning and memory or visuospatial abilities, in both humans and rodents. However, despite promising laboratory evidence, clinical translation has been dampened by a limited pharmacological characterization of the single bioactive components of the herbal products. Depicting the contribution of the single phytochemicals to the phytocomplex's pharmacological efficacy could enable the comprehension of their potential synergistic activity, leading to phytotherapy inclusion in the existing therapeutic package against cognitive decline.

Comprehensive Exploration of the Neuroprotective Mechanisms of Ginkgo biloba Leaves in Treating Neurological Disorders

Neurological disorders (NDs) are diseases that seriously affect the health of individuals worldwide, potentially leading to a significant reduction in the quality of life for patients and their families. Herbal medicines have been widely used in the treatment of NDs due to their multi-target and multi-pathway features. Ginkgo biloba leaves (GBLs), one of the most popular herbal medicines in the world, have been demonstrated to present therapeutic effects on NDs. However, the pharmacological mechanisms of GBLs in the treatment of neurological disorders have not been systematically summarized. This study aimed to summarize the molecular mechanism of GBLs in treating NDs from the cell models, animal models, and clinical trials of studies. Four databases, i.e., PubMed, Google Scholar, CNKI, and Web of Science were searched using the following keywords: "Ginkgo biloba", "Ginkgo biloba extract", "Ginkgo biloba leaves", "Ginkgo biloba leaves extract", "Neurological disorders", "Neurological diseases", and "Neurodegenerative diseases". All items meeting the inclusion criteria on the treatment of NDs with GBLs were extracted and summarized. Additionally, PRISMA 2020 was performed to independently evaluate the screening methods. Out of 1385 records in the database, 52 were screened in relation to the function of GBLs in the treatment of NDs; of these 52 records, 39 were preclinical trials and 13 were clinical studies. Analysis of pharmacological studies revealed that GBLs can improve memory, cognition, behavior, and psychopathology of NDs and that the most frequently associated GBLs are depression, followed by Alzheimer's disease, stroke, Huntington's disease, and Parkinson's disease. Additionally, the clinical studies of depression, AD, and stroke are the most common, and most of the remaining ND data are available from in vitro or in vivo animal studies. Moreover, the possible mechanisms of GBLs in treating NDs are mainly through free radical scavenging, anti-oxidant activity, anti-inflammatory response, mitochondrial protection, neurotransmitter regulation, and antagonism of PAF. This is the first paper to systematically and comprehensively investigate the pharmacological effects and neuroprotective mechanisms of GBLs in the treatment of NDs thus far. All findings contribute to a better understanding of the efficacy and complexity of GBLs in treating NDs, which is of great significance for the further clinical application of this herbal medicine.

Ginkgo Biloba Leaf Extract Improves an Innate Immune Response of Peripheral Blood Leukocytes of Alzheimer's Disease Patients

BACKGROUND

One of the main features of Alzheimer's disease (AD) pathology is failure in innate immune response and chronic inflammation. Lack of effective AD treatment means that more attention is paid to alternative therapy and drugs of natural origin, such as extract of Ginkgo biloba (EGb). The purpose of this study was to investigate the effect of EGb on the mechanisms of innate immune response of peripheral blood leukocytes (PBLs) in AD patients.

METHODS

In AD patients and healthy-age matched controls, the effect of EGb on two of innate immune reactions, i.e., PBLs resistance to viral infection ex vivo and production of cytokines, namely TNF-α, IFN-γ, IL-1β, IL-10, IL-15, and IFN-α, were investigated. The influence of EGb on inflammatory-associated genes expression that regulate innate immune response to viral infection and cytokine production, namely IRF-3, IRF-7, tetherin, SOCS1, SOCS3, NFKB1, p65, and MxA was also examined.

RESULTS

A beneficial effect of EGb especially in AD women was observed. EGb decreased production of TNF-α, IFN-γ, and IL-10 and increased IL-15 and IL-1β. The effect was more pronouncement in AD group. EGb also downregulated expression of investigated genes.

CONCLUSIONS

EGb may have an advantageous properties for health management in elderly and AD sufferers but especially in women with AD. Improving peripheral innate immune cells' activity by adding EGb as accompanying treatment in AD may be, in the long term, a good course to modify the disease progression.

Astilbin ameliorates oxidative stress and apoptosis in D-galactose-induced senescence by regulating the PI3K/Akt/m-TOR signaling pathway in the brains of mice

An increasing amount of evidence has shown that injection of D-galactose (D-gal) can mimic natural aging that typically is associated with brain injury. Oxidative stress and apoptosis has been shown to play an essential role in aging process. The purpose of this study was to investigate the protective effectsof astilbin (ASB) on D-Gal-induced agingin miceand to further explore the underlying mechanisms. We randomly divided 50 mice into 5 groups.To establish this model of aging, 40micewere intraperitoneally administered D-Gal (500 mg/kg). The mice in the treatmentgroupswere intragastricaly administratedASB at doses of 40 and 80 mg/kg. H&E and TUNEL staining were used to determine the effect of ASB on the number of apoptotic cells in the brain. Furthermore, biochemical indices of serum, oxidative stress factors, and apoptosis factors were determined to clarify the underlying mechanism using reagent test kits and western blotting. The results showed that varying doses of ASB could improve D-Gal-induced histopathological damageand significantly alleviatedthe aging induced by D-Galin mice. ASB remarkably decreased the activities of malondialdehyde (MDA)(p < 0.01)and Acetyl cholinesterase (AChE)(p < 0.05) and markedlyincreased the content of catalase (CAT)(p < 0.01)and superoxide dismutase (SOD)(p < 0.01), respectively. In addition, Western blotting revealed thatASB treatment (40 mg/kg)attenuated the D-gal-induced Bax and Caspase 3 protein expression(p < 0.01) and reversed the increase in Bcl-2protein expressionin brain. Moreover, ASB treatment significantly upregulated the protein expression ofp-PI3K/PI3K and altered the p-Akt/Akt ratio (p < 0.05), while inhibiting the expression of p-m-TOR relative to m-TOR(p < 0.05). Moreover, the expression of P53 tended to decreasein the low ASB treatmentgroup (40 mg/kg), whereas no change was observed in the high ASB treatmentgroup (80 mg/kg). In the intestinal flora, the richness of the normal group and the ASB group was higher than that of the D-Gal group. Heat map analysis also showed that ASB promoted Lactobacillus and other probiotics and also confirmed the advantages of ASB. The observed changes in intestinal flora further verified the efficacy of ASB.

Astragaloside IV prevents memory impairment in D-galactose-induced aging rats via the AGEs/RAGE/ NF-κB axis

BACKGROUND

We investigated the effects of astragaloside IV (AS-IV) on memory function in aging rats mimicked by D-galactose administration and explored the potential molecular mechanisms.

METHODS

Twenty-seven male rats were randomly divided into control group (N = 9), model group (N = 9), and AS-IV treated group (N = 9). Aging model was stimulated by D-galactose (400 mg/kg/d, i.p., dissolved in saline) for 8 weeks in rats. The general status of the rats was observed weekly. Learning and memory function was determined using the eight-arm radical maze and step-down test. Pathological changes in the hippocampal CA1 region were determined by hematoxylin and eosin staining. Organ indexes, superoxide dismutase (SOD) activity and malonaldehyde (MDA) content in the serum were measured. Expression of advanced glycation end products (AGEs), receptor for AGEs (RAGE), nuclear factor-κB (NF-κB), interleukin (IL)-6, IL-1β and tumor necrosis factor-α (TNF-α) were detected by enzyme-linked immunosorbent assay, real-time polymerase chain reaction or western blotting.

RESULTS

AS-IV improved the general status of the aging rats induced by D-galactose, prevented the impairment of memory function, organ indexes, and the pathological damage of the hippocampus. From the prospective of oxidative stress, AS-IV increased sera SOD activity and decreased MDA content. Additionally, AS-IV also reduced the inflammatory response by reducing hippocampal IL-1β, TNF-α, and IL-6 expression. Importantly, AS-IV prevented D-galactose-induced expression of AGEs, RAGE and NF-κB in the hippocampus.

CONCLUSION

AS-IV could prevent D-galactose-induced aging and memory impairment in rats, likely via regulation of inflammatory response, which was modulated by AGEs/RAGE/NF-κB axis.

Establishment of a rat model with ageing insomnia induced by D-galactosef and para-chlorophenylalanine

The current study aimed to establish a rat model of ageing insomnia induced by D-galactose and/or para-chlorophenylalanine. Following establishment of the model, body weights were measured, and Morris water maze and pentobarbital-induced sleep tests were performed. The serum levels of inflammatory mediators and the neural levels of neurotransmitters were detected. The results demonstrated that the body weights of PCPA+D-gal-induced ageing insomnia rats decreased significantly. Ageing insomnia rats exhibited longer latencies to the platform in the Morris water maze tests and fewer target crossings. The sleep latency of the model rats was longer and sleep time was shorter by contrast. The relative expression of hippocampal IL-6, TNF-α, NF-κB and mGluR2 mRNA of the PCPA+D-gal-induced ageing insomnia group was higher, while the relative expression of 5-HT_1AR and GABA_AR_a1 mRNA were lower. The serum levels of IL-1β, IL-6, TNF-α and brain level of glutamate increased in the PCPA+D-gal-induced ageing insomnia group, while the levels of 5-HT and GABA decreased. In conclusion, memory function, sleep time, expression of inflammatory factors and neurotransmitters are altered in ageing insomnia rats induced by D-galactose and para-chlorophenylalanine, indicating the successful establishment of a murine model of ageing insomnia.