Ginseng improves cognitive deficit via the RAGE/NF-κB pathway in advanced glycation end product-induced rats

Apigenin and baicalein ameliorate thoracic aortic structural deterioration and cognitive deficit via inhibiting AGEs/RAGE/NF-κB pathway in D-galactose-induced aging rats

Apigenin and baicalein are structurally related flavonoids that have been reported to have multiple pharmacological activities. The aim of this study was to investigate the protective effects and potential mechanisms of apigenin and baicalein in D-galactose-induced aging rats. First, apigenin and baicalein showed remarkable antioxidant activity and anti-glycation activity in vitro. Secondly, the protective effects of apigenin and baicalein on aging rats were investigated. We found that apigenin and baicalein supplementation significantly ameliorated aging-related changes such as declines in the spatial learning and memory and histopathological damage of the hippocampus and thoracic aorta. In addition, our data showed that apigenin and baicalein alleviated oxidative stress as illustrated by decreasing MDA level, increasing SOD activity and GSH level. Further data showed that they significantly reduced the accumulation of advanced glycation end products (AGEs), inhibited the expression of RAGE, down-regulated phosphorylated nuclear factor (p-NF-κB (p65)). Our results suggested that the protective effects of apigenin and baicalein on aging rats were at least partially related to the inhibition of AGEs/RAGE/NF-κB pathway and the improvement of oxidative damage. Overall, apigenin and baicalein showed almost equal anti-aging efficacy. Our results provided an experimental basis for the application of apigenin and baicalein to delay the aging process.

A mechanistic exploration of the metabolome of African mango seeds and its potential to alleviate cognitive impairment induced by high-fat/high-carbohydrate diets: Involvement of PI3K/AKT/GSK-3β/CREB, PERK/CHOP/Bcl-2, and AMPK/SIRT-1/mTOR Axes

ETHNOPHARMACOLOGICAL RELEVANCE

Irvingia gabonensis (Aubry-Lecomte ex O'Rorke) Baill., also known as "African mango" or "bush mango", belonging to family Irvingiaceae, has been mostly used as food and traditional medicine for weight loss and to enhance the health.

AIM OF THE STUDY

The overconsumption of high-fat and high-carbohydrate (HFHC) food induces oxidative stress, leading to neurological and cognitive dysfunction. Consequently, there is an immediate need for effective treatment. Hence, this study explored the efficacy of orlistat, metformin, and I. gabonensis seeds' total aqueous extract (IG SAE) in addressing HFHC-induced cognitive impairment by mitigating oxidative stress and their underlying mechanistic pathways.

MATERIALS AND METHODS

Initially, the secondary metabolite profile of IG SAE is determined using high-performance liquid chromatography coupled with a mass detector (UHPLC/MS). The in vivo study involves two phases: an established model phase with control (10 rats on a standard diet) and HFHC diet group (50 rats) for 3 months. In the study phase, HFHC is divided into 5 groups. The first subgroup receives HFHC diet only, while the remaining groups each receive HFHC diet with either Orlistat, metformin, or IG SAE at doses of 100 mg/kg and 200 mg/kg, respectively, for 28 days.

RESULTS

More than 150 phytoconstituents were characterized for the first holistic approach onto IG metabolome. Characterization of IG SAE revealed that tannins dominate metabolites in the plant. Total phenolics and flavonoids were estimated to standardize our extract (77.12 ± 7.09 μg Gallic acid equivalent/mg extract and 8.039 ± 0.53 μg Rutin equivalent/mg extract, respectively). Orlistat, metformin, and IG SAE successfully reduced the body weight, blood glucose level, lipid profile, oxidative stress and neurotransmitters levels leading to improved behavioral functions as well as histological alternation. Also, IG SAE halted inflammation, apoptosis, and endoplasmic reticulum stress, together with promoting autophagy, via modulation of PI3K/AKT/GSK-3β/CREB, PERK/CHOP/Bcl-2 and AMPK/SIRT-1/m-TOR pathways.

CONCLUSION

Metformin, orlistat, and IG SAE offer a promising multi-target therapy to mitigate HFHC diet-induced oxidative stress, addressing cognitive function. This involves diverse molecular mechanisms, particularly the modulation of inflammation, ER stress, and both PI3K/AKT/GSK-3β/CREB and AMPK/SIRT-1/m-TOR pathways. Furthermore, the higher dose of IG SAE demonstrated effects comparable to orlistat and metformin across most studied parameters.

Current Progress on Neuroprotection Induced by Artemisia, Ginseng, Astragalus, and Ginkgo Traditional Chinese Medicines for the Therapy of Alzheimer's Disease

Aging is associated with the occurrence of diverse degenerative changes in various tissues and organs and with an increased incidence of neurological disorders, especially neurodegenerative diseases such as Alzheimer's disease (AD). In recent years, the search for effective components derived from medicinal plants in delaying aging and preventing and treating neurodegenerative diseases has been increasing and the number of related publications shows a rising trend. Here, we present a concise, updated review on the preclinical and clinical research progress in the assessment of the therapeutic potential of different traditional Chinese medicines and derived active ingredients and their effect on the signaling pathways involved in AD neuroprotection. Recognized by their multitargeting ability, these natural compounds hold great potential in developing novel drugs for AD.

Receptor for advanced glycation end products aggravates cognitive deficits in type 2 diabetes through binding of C-terminal AAs 2-5 to mitogen-activated protein kinase kinase 3 (MKK3) and facilitation of MEKK3-MKK3-p38 module assembly

In this study, we explored the precise mechanisms underlying the receptor for advanced glycation end products (RAGE)‐mediated neuronal loss and behavioral dysfunction induced by hyperglycemia. We used immunoprecipitation (IP) and GST pull‐down assays to assess the interaction between RAGE and mitogen‐activated protein kinase kinase 3 (MKK3). Then, we investigated the effect of specific mutation of RAGE on plasticity at hippocampal synapses and behavioral deficits in db/db mice through electrophysiological recordings, morphological assays, and behavioral tests. We discovered that RAGE binds MKK3 and that this binding is required for assembly of the MEKK3‐MKK3‐p38 signaling module. Mechanistically, we found that activation of p38 mitogen‐activated protein kinase (MAPK)/NF‐κB signaling depends on mediation of the RAGE‐MKK3 interaction by C‐terminal RAGE (ctRAGE) amino acids (AAs) 2‐5. We found that ctRAGE R2A‐K3A‐R4A‐Q5A mutation suppressed neuronal damage, improved synaptic plasticity, and alleviated behavioral deficits in diabetic mice by disrupting the RAGE‐MKK3 conjugation. High glucose induces direct binding of RAGE and MKK3 via ctRAGE AAs 2‐5, which leads to assembly of the MEKK3‐MKK3‐p38 signaling module and subsequent activation of the p38MAPK/NF‐κB pathway, and ultimately results in diabetic encephalopathy (DE).

Panax Ginseng alleviates thioacetamide-induced liver injury in ovariectomized rats: Crosstalk between inflammation and oxidative stress

Liver diseases impose a substantial health problem. Female hormones play a crucial role in the protection against chronic inflammatory diseases. Fifty female rats were allocated into five groups (n = 10). Group I comprised sham-operated rats. The remaining groups underwent ovariectomy at the beginning of the experiment. Group II served as the ovariectomy-control group. Groups III, IV & V received thioacetamide (TAA; 300 mg/kg; i.p.) to induce liver injury 6 weeks after ovariectomy. Group III served as the TAA-control group. Groups IV & V received panax ginseng (100 and 300 mg/kg/day, p.o.) for 6 weeks post TAA administration. All groups were investigated for liver function tests along with total antioxidant capacity (TAC), tumor necrosis factor-α (TNF-α) and advanced glycation end products (AGEs). Histopathological examination of liver tissues was performed followed by immunohistochemical staining for nuclear factor kappa-B (NF-kβ p65) and myeloperoxidase (MPO). Ovariectomized-rats showed a non-significant change in the measured parameters while TAA administration resulted in significant liver damage. Panax ginseng at both dose levels significantly improved the serum liver function tests and TAC along with decreasing the AGEs and TNF-α. It also restored the histopathological picture of liver tissue and decreased hepatic tissue inflammation via reduction of MPO and NF-kβ p65 immunoreactivity. The current study is the first to elucidate the effect of panax ginseng against TAA-induced liver injury in ovariectomized rats which mimic aged post-menopausal estrogen-deficient females. The study demonstrates the crosstalk between AGEs, NF-kβ and MPO in the modulation of inflammation. Panax ginseng possesses antioxidant and anti-inflammatory properties.

Therapeutic Targets for the Treatment of Comorbidities Associated with Epilepsy

One of the most common neurological disorders, which occurs among 1% of the population worldwide, is epilepsy. Therapeutic failure is common with epilepsy and nearly about 30% of patients fall in this category. Seizure suppression should not be the only goal while treating epilepsy but associated comorbidities, which can further worsen the condition, should also be considered. Treatment of such comorbidities such as depression, anxiety, cognition, attention deficit hyperactivity disorder and, various other disorders which co-exist with epilepsy or are caused due to epilepsy should also be treated. Novel targets or the existing targets are needed to be explored for the dual mechanism which can suppress both the disease and the comorbidity. New therapeutic targets such as IDO, nNOS, PAR1, NF-κb are being explored for their role in epilepsy and various comorbidities. This review explores recent therapeutic targets for the treatment of comorbidities associated with epilepsy.

Ciprofloxacin and dexamethasone in combination attenuate S. aureus induced brain abscess via neuroendocrine-immune interaction of TLR-2 and glucocorticoid receptor leading to behavioral improvement

Staphylococcus aureus induced brain abscess is a critical health concern throughout the developing world. The conventional surgical intervention could not regulate the abscess-induced brain inflammation. Thus further study over the alternative therapeutic strategy for treating a brain abscess is of high priority. The resident glial cells recognize the invading S. aureus by their cell surface Toll-like receptor-2 (TLR-2). Glucocorticoid receptor (GR) was known for its immunosuppressive effects. In this study, an attempt had been taken to utilize the functional relationship or cross-talking between TLR-2 and GR during the pathogenesis of brain abscesses. Here, the combination of an antibiotic (i.e. ciprofloxacin) and dexamethasone was used to regulate the brain inflammation either in TLR-2 or GR blocking condition. We were also interested to figure out the possible impact of alternative therapy on behavioral impairments. The results indicated that combination treatment during TLR-2 blockade significantly reduced the bacterial burden and abscess area score in the infected brain. However, marked improvements were observed in anxiety, depression-like behavior, and motor co-ordination. The combination treatment after TLR-2 blocking effectively scavenged free radicals (H₂O₂, superoxide anion, and NO) through modulating antioxidant enzyme activities that ultimately control S. aureus induced glial reactivity possibly via up-regulating GR expression. The exogenous dexamethasone might regulate the GR expression in the brain by increasing the corticosterone concentration and the GC-GR mediated signaling. Therefore, this in-vivo study demonstrates the possible regulatory mechanism of bacterial brain abscess that involved TLR-2 and GR as a part of neuroendocrine-immune interaction.

Ginsenoside derivatives inhibit advanced glycation end-product formation and glucose-fructose mediated protein glycation in vitro via a specific structure-activity relationship

Ginseng (Panax ginseng and red ginseng) extract has been reported to inhibit the formation of advanced glycation end-products (AGEs); however, the potential inhibitory activity of its major constituents (ginsenosides) against AGE formation is still unknown. In the present study, we investigated the inhibitory effect of ginsenoside derivatives on AGE formation. Herein, we assessed the activity of 22 ginsenosides, most of which significantly inhibited fluorescent AGE formation. Notably, ginsenoside Rh2, ginsenoside Rh1, and compound K exhibited the most potent AGE inhibitory potential with IC₅₀ values of 3.38, 8.42, and 10.85 µM, respectively. The structure- activity relationship revealed that the presence of sugar moieties, hydroxyl groups, and their linkages, and the stereostructure of the ginsenoside skeleton played an important role in the inhibition of AGE formation. Furthermore, the inhibitory activity of the most active ginsenoside Rh2 on fructose-glucose-mediated protein glycation and oxidation of bovine serum albumin (BSA) was explored. Rh2 (0.1-12.5 µM) inhibited the formation of fluorescent AGE and non-fluorescent AGE, as well as the level of fructosamine and prevented protein oxidation by decreasing protein carbonyl formation and protein thiol group modification. Rh2 also suppressed the formation of the β-cross amyloid structure of BSA. Ginsenosides might be promising new anti-glycation agents for the prevention of diabetic complications via inhibition of AGE formation and oxidation-dependent protein damage.

Protective effects of ginsenoside Rg2 against memory impairment and neuronal death induced by Aβ25-35 in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Ginsenoside Rg2 is an important ingredient of Panax ginseng which often appears in ancient prescriptions for forgetfulness. Ginsenoside Rg2 exert neuroprotective effects and could be a new potential medicine to treat AD. In our previous study, we reported that ginsenoside Rg2 appears protect PC12 cells against Amyloid β-fragment (25-35) (Aβ_25-35)-induced apoptosis via the PI3K/Akt pathway. However, there are no in vivo studies on the protective effects of ginsenoside Rg2 on Aβ-induced neurotoxicity.

AIM OF THE STUDY

The present study was performed to investigate the protective effects of ginsenoside Rg2 against Aβ_25-35-induced memory impairment, and its underlying mechanisms in rats.

MATERIALS AND METHODS

An Alzheimer's Disease (AD) rat model was established by injecting the rats with Aβ_25-35 (1 μg/μl). Cognitive performance was evaluated by the Morris Water Maze test (MWM). The brain sections were processed and neuronal apoptosis in the hippocampus was evaluated by Hematoxylin and Eosin staining (H&E). To explore the anti-neuronal apoptosis mechanism of ginsenoside Rg2, we analyzed the protein expression of Bcl-2/Bax, caspase-3, and phospho-protein kinase B/protein kinase B (p-Akt/Akt) via western blot.

RESULTS

A significant improvement in cognitive function was observed in administrated ginsenoside Rg2 AD rats. The histological injury in hippocampus CA1 induced by Aβ_25-35 was inhibited following administration of the ginsenoside Rg2. Ginsenoside Rg2 increase the Bcl-2/Bax ratio, attenuate the cleavage of caspase-3, and enhance the phosphorylation of Akt.

CONCLUSIONS

These findings suggest that ginsenoside Rg2 could ameliorate Aβ_25-35-induced cognitive dysfunction by activating the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway.

Hyperglycemia induces RAGE-dependent hippocampal spatial memory impairments

Diabetes is a prevalent metabolic disorder that has long been associated with changes in different regions of the brain, including the hippocampus. Changes in hippocampal synaptic plasticity and subsequent impairment in cognitive functions such as learning and memory, are well documented in animal models of type 1 and type 2 diabetes. It is known that RAGE contributes to peripheral micro- and macro-vascular complications of diabetes. However, it is still unknown if RAGE plays a similar role in the development of CNS complications of diabetes. Therefore, we hypothesize that RAGE contributes to cognitive dysfunction, such as learning and memory impairments, in a mouse model of STZ-induced hyperglycemia. Control and STZ-induced hyperglycemic mice from WT and RAGE-KO groups were used for the behavioral experiments. While STZ-induced hyperglycemia decreased locomotor activity in the open field (OF) test, it did not affect the recognition memory in the novel object recognition (NOR) test in either genotype. Spatial memory, however, was impaired in STZ-induced hyperglycemic mice in WT but not in RAGE-KO group in both the Barnes maze (BM) and the Morris water maze (MWM) tests. Consistently, the RAGE antagonist FPS-ZM1 protected WT STZ-induced hyperglycemic mice from spatial memory impairment in the BM test. Our findings indicate that the parameters associated with locomotor activity and recognition memory were independent of RAGE in STZ-induced hyperglycemic mice. In contrast, the parameters associated with hippocampal-dependent spatial memory were dependent on RAGE expression.

Shenzao jiannao oral liquid, an herbal formula, ameliorates cognitive impairments by rescuing neuronal death and triggering endogenous neurogenesis in AD-like mice induced by a combination of Aβ42 and scopolamine

ETHNOPHARMACOLOGICAL RELEVANCE

According to the theory of traditional Chinese medicine (TCM), Alzheimer's disease (AD) is identified as "forgetfulness" or "dementia", and is mainly caused by "kidney essence deficiency" which ultimately induces "encephala reduction". Therefore, herbal formulas possessing the efficacy of nourishing kidney essence or replenishing brain marrow are commonly served as effective strategies for AD treatment. Shenzao jiannao oral liquid (SZJN), a traditional Chinese preparation approved by the China Food and Drug Administration (CFDA), is used for the treatment of insomnia and mind fatigue at present for its efficacy of nourishing kidneys. In present study, we found that SZJN could improve cognitive function of AD-like mice.

AIMS OF STUDY

This study aims to investigate the effects of SJZN on ameliorating cognitive deficits of AD-like mouse model, and to illuminate the underlying mechanisms from the perspective of neuroprotection and neurogenesis.

MATERIALS AND METHODS

Kunming mice (28 ± 2 g) were randomly allocated into seven groups: control, sham, model, donepezil and SZJN groups (low, middle and high). The AD mouse model was established by Aβ42 combined with scopolamine. SZJN were intragastrically administrated at doses of 0.3, 1.5 and 7.5 g/kg for 28 days. Morris water maze (MWM) test was applied to determine the cognitive function. Hematoxylin eosin (HE) and Nissl staining were carried out to evaluate pathological damages in the cortex and hippocampal tissues. To explore the protective effects of SZJN on multiple pathogenic factors of AD, protein levels of Aβ42, glial fibrillary acidic protein (GFAP), Bax, Bcl-2, Caspase-3, synaptophysin (SYP), brain-derived neurotrophic factor (BDNF), and neurogenesis related proteins were assessed using Immunofluorescence (IF) and western blot analysis. In vitro, the AD cell model was established by transduction of APP_695swe genes into Neural stem cells (NSCs) isolated from the hippocampal tissues of neonatal C57BL/6 mice. Cell viability assay and neurosphere formation assay were carried out to verify the efficacy of SZJN on proliferation of NSCs.

RESULTS

Our results demonstrated that SZJN (1.5 g/kg and 7.5 g/kg) treatment significantly ameliorated cognitive deficits of AD-like mice. SZJN (7.5 g/kg) treatment significantly retarded the pathological damages including neuronal degeneration, neuronal apoptosis, Aβ peptides aggregation and reaction of astrocytes in AD-like mice. In addition, SZJN (7.5 g/kg) increased the expression of BDNF and SYP, and restored the abnormal level of MDA and SOD in the brain of AD-like mice. Furthermore, SZJN treatment for 28 days remarkably increased the proliferation of NSCs evidenced by more Nestin⁺ and BrdU⁺ cells in the hippocampal DG regions, and increased the amount of mature neurons marked by NeuN both in the cortex and hippocampal DG regions. In vitro, SZJN treatement (16, 32, 64 mg/ml) promoted the proliferation of NSCs evidenced by the increased amount and enlarged size of the neurospheres (p < 0.05).

CONCLUSIONS

Our findings indicated that SZJN could ameliorate cognitive deficits by protecting neurons from death and triggering endogenous neurogenesis. Therefore, SZJN may be considered as a promising agent to restore neuronal loss and deter the deterioration in AD patients.

PHYTOADAPTOGENS IN THE TUMOURS BIOTHERAPY AND GERIATRICS (PART 1)

The review reflects the history of phytoadaptogens studies (ginseng, eleutherococcus, etc.), which are considered to be geroprotectors by Eastern medicine for centures. They have a complex of protective effects on the body, as well as increasing its antitumor resistance. The first part of the review describes the antistress, immuno- and hormone-modulating, cognitive and neuroprotective properties of adapto gens. Together with the synchronizing effects on biorthms adaptogens are essential for preventive oncology.

Carthamus tinctorius L. Extract ameliorates cerebral ischemia-reperfusion injury in rats by regulating matrix metalloproteinases and apoptosis

We investigate the protective effect of Carthamus tinctorius L. (CTL, also known as Honghua in China or Safflower) on cerebral ischemia-reperfusion and explored the possible mechanisms on regulating apoptosis and matrix metalloproteinases (MMPs). High-performance liquid chromatography method with diode array detection analysis was established to analyze the components of CTL. Middle cerebral artery occlusion rats model was established to evaluate Neurological Function Score and hematoxylin-eosin staining, as well as triphenyltetrazolium was used to examine the infarction area ratio. Transferase-mediated dUTP nick-end labeling was performed for the apoptosis. Apoptosis-related factors, including B-cell lymphoma-2 (Bcl-2), Bax and Caspase3, and MMPs-related MMP2, MMP9, tissue inhibitor of metalloproteinases 1 (TIMP1) in ischemic brain, were assayed by Western blot, reverse transcription polymerase chain reaction, and immunohistochemistry. The data showed that CTL (2, 4 g crude drug/kg/d) treatment could significantly reduce the ischemic damage in brain tissue and improve a significant neurological function score. In addition, CTL could also attenuate apoptosis degree of brain tissues and regulate Bcl-2, Bax, and Caspase 3 and also have a significant decrease on MMP-9 expression, followed by a significant increase of TIMP1 protein expression. These findings indicated that regulation of CTL on apoptosis and MMPs contributed to its protective effect on ischemia/reperfusion injury.

Effects of Ginseng on Neurological Disorders

Ginseng (Panax ginseng Meyer), a famous traditional medicinal herb, has been widely used for many centuries. Numerous studies have shown that ginseng has a positive effect on the prevention and treatment of neurological disorders. In this review, we summarized the effects of ginseng in treating neurological diseases, particularly the anti-depressant effects of ginseng. Furthermore, its potential mechanism was also outlined. Therefore, this review may provide new insight into the treatment of ginseng on neurological diseases.

Natural Products and Their Bioactive Compounds: Neuroprotective Potentials against Neurodegenerative Diseases

In recent years, natural products, which originate from plants, animals, and fungi, together with their bioactive compounds have been intensively explored and studied for their therapeutic potentials for various diseases such as cardiovascular, diabetes, hypertension, reproductive, cancer, and neurodegenerative diseases. Neurodegenerative diseases, including Alzheimer's disease, Huntington's disease, Parkinson's disease, and amyotrophic lateral sclerosis are characterized by the progressive dysfunction and loss of neuronal structure and function that resulted in the neuronal cell death. Since the multifactorial pathological mechanisms are associated with neurodegeneration, targeting multiple mechanisms of actions and neuroprotection approach, which involves preventing cell death and restoring the function to damaged neurons, could be promising strategies for the prevention and therapeutic of neurodegenerative diseases. Natural products have emerged as potential neuroprotective agents for the treatment of neurodegenerative diseases. This review focused on the therapeutic potential of natural products and their bioactive compounds to exert a neuroprotective effect on the pathologies of neurodegenerative diseases.

Enhanced Neuroprotective Effects of Panax ginseng G115® and Ginkgo biloba GK501® Combinations In Vitro Models of Excitotoxicity

Neurological-related disorders are seen as an increasingly important aspect of welfare. While conventional medicine is still the mainstay for the treatment of these diseases, it is becoming apparent that patients are also seeking more natural and preventative interventions. Panax ginseng G115^® and Ginkgo biloba GK501^® extracts alone or in combination were used in two in vitro experimental models of primary cultures exposed to excitotoxicity: rat organotypic hippocampal slices exposed to either 5 µM kainic acid or 10 µM N-Methyl-d-aspartate for 24 hours, and mixed cortical cells exposed to 300 µM NMDA for 10 min. Cell death in the Cornu Ammonis areas CA3 or CA1 subregions of slices was quantified by measuring propidium iodide fluorescence, whereas in cortical cells, it was assessed by measuring the amount of lactate dehydrogenase. In slices, treatment with extracts alone or in combination significantly attenuated CA3 and CA1 damage induced by exposure to kainic acid or NMDA, respectively. A similar neuroprotective effect was observed in cortical cells exposed to NMDA. Analysis of cell signaling pathways found that the two extracts induced an increase of the phosphorylation and they reversed the decrease of phosphorylation of ERK1/2 and Akt induced by kainic acid and NMDA in organotypic hippocampal slices. These results suggest that P. ginseng G115^® and G. biloba GK501^® extracts may mediate their effects by activating phosphorylation of ERK1/2 and Akt signaling pathways, protecting against excitotoxicity-induced damage in in vitro models.

Role of the Glyoxalase System in Alzheimer's Disease

Alzheimer's disease (AD) is an insidious and progressive neurodegenerative disease. The main pathological features of AD are the formation of amyloid-β deposits in the anterior cerebral cortex and hippocampus as well as the formation of intracellular neurofibrillary tangles. Thus far, accumulating evidence shows that glycation is closely related to AD. As a final product resulting from the crosslinking of a reducing sugar or other reactive carbonyls and a protein, the advanced glycation end products have been found to be associated with the formation of amyloid-β and neurofibrillary tangles in AD. As a saccharification inhibitor, the glyoxalase system and its substrate methylglyoxal (MG) were certified to be associated with AD onset and development. As an active substance of AGEs, MG could cause direct or indirect damage to nerve cells and tissues. MG is converted to D-lactic acid after decomposition by the glyoxalase system. Under normal circumstances, MG metabolism is in a dynamic equilibrium, whereas MG accumulates in cells in the case of aging or pathological states. Studies have shown that increasing glyoxalase activity and reducing the MG level can inhibit the generation of oxidative stress and AGEs, thereby alleviating the symptoms and signs of AD to some extent. This paper focuses on the relevant mechanisms of action of the glyoxalase system and MG in the pathogenesis of AD, as well as the potential of inhibiting the production of advanced glycation end products in the treatment of AD.

D-ribose is elevated in T1DM patients and can be involved in the onset of encephalopathy

Although many mechanisms have been proposed for diabetic encephalopathy in type 2 diabetes mellitus (T2DM), the risk factors for cognitive impairment in type 1 diabetes mellitus (T1DM) are less clear. Here, we show that streptozotocin (STZ)-induced T1DM rats showed cognitive impairment in both Y maze and Morris water maze assays, accompanied with D-ribose was significantly increased in blood and urine, in addition to D-glucose. Furthermore, advanced glycation end products (AGE), Tau hyperphosphorylation and neuronal death in the hippocampal CA4/DG region were detected in T1DM rats. The expression and activity of transketolase (TKT), an important enzyme in the pentose shunt, were decreased in the brain, indicating that TKT may be involved in D-ribose metabolism in T1DM. Support for these change was demonstrated by the activation of TKT with benfotiamine (BTMP) treatment. Decreased D-ribose levels but not D-glucose levels; markedly reduced AGE accumulation, Tau hyperphosphorylation, and neuronal death; and improved cognitive ability in T1DM rats were shown after BTMP administration. In clinical investigation, T1DM patients had high D-ribose levels in both urine and serum. Our work suggests that D-ribose is involved in the cognitive impairment in T1DM and may provide a potentially novel target for treating diabetic encephalopathy.

The G115 standardized ginseng extract: an example for safety, efficacy, and quality of an herbal medicine

Ginseng products on the market show high variability in their composition and overall quality. This becomes a challenge for both consumers and health-care professionals who are in search of high-quality, reliable ginseng products that have a proven safety and efficacy profile. The botanical extract standardization is of crucial importance in this context as it determines the reproducibility of the quality of the product that is essential for the evaluation of effectiveness and safety. This review focuses on the well-characterized and standardized ginseng extract, G115, which represents an excellent example of an herbal drug preparation with constant safety and efficacy within the herbal medicinal products. Over the many decades, extensive preclinical and clinical research has been conducted to evaluate the efficacy and safety of G115. In vitro and in vivo studies of G115 have shown pharmacological effects on physical performance, cognitive function, metabolism, and the immune system. Furthermore, a significant number of G115 clinical studies, most of them double-blind placebo-controlled, have reinforced the findings of preclinical evidence and proved the efficacy of this extract on blood glucose and lipid regulation, chronic obstructive pulmonary disease, energy, physical performance, and immune and cognitive functions. Clinical trials and 50 years of presence on the market are proof of a good safety profile of G115.

Comprehensive review on the interaction between natural compounds and brain receptors: Benefits and toxicity

Given their therapeutic activity, natural products have been used in traditional medicines throughout the centuries. The growing interest of the scientific community in phytopharmaceuticals, and more recently in marine products, has resulted in a significant number of research efforts towards understanding their effect in the treatment of neurodegenerative diseases, such as Alzheimer's (AD), Parkinson (PD) and Huntington (HD). Several studies have shown that many of the primary and secondary metabolites of plants, marine organisms and others, have high affinities for various brain receptors and may play a crucial role in the treatment of diseases affecting the central nervous system (CNS) in mammalians. Actually, such compounds may act on the brain receptors either by agonism, antagonism, allosteric modulation or other type of activity aimed at enhancing a certain effect. The current manuscript comprehensively reviews the state of the art on the interactions between natural compounds and brain receptors. This information is of foremost importance when it is intended to investigate and develop cutting-edge drugs, more effective and with alternative mechanisms of action to the conventional drugs presently used for the treatment of neurodegenerative diseases. Thus, we reviewed the effect of 173 natural products on neurotransmitter receptors, diabetes related receptors, neurotrophic factor related receptors, immune system related receptors, oxidative stress related receptors, transcription factors regulating gene expression related receptors and blood-brain barrier receptors.

Panax ginseng for Frailty-Related Disorders: A Review

This review aims to understand the clinical efficacy of Panax ginseng (PG) for managing frailty-related disorders by reviewing meta-analyses, systematic reviews, and randomized clinical trial data. PG is widely used in traditional medicine, mainly in East Asia. It has traditionally been indicated for the collapse of qi or for abandoned conditions that manifest as shallow breathing, shortness of breath, cold limbs, profuse sweating, a low pulse rate, or weakness. In accordance with these indications, PG is used for managing conditions such as aging, inflammation, and cancer. PG is also used in some functional foods or supplements. Some studies have shown the effects of ginsenosides, which are the major constituents of PG. With regard to pharmacological activities of ginseng saponins, it has been presumed that these ginsenosides are metabolized into active forms by human intestinal microbiota after being taken orally. Therefore, we focused on reviewing the data of clinical studies on PG. Although there has been no study that directly investigated the effect of PG on frailty, a number of clinical studies have been conducted to investigate the efficacy and safety of PG and its interactions with other modern ginseng medications and ginseng-containing formulas. We searched the randomized controlled trial data from 1995 to 2018 and reviewed the potential effects of PG on frailty-related disorders. We reviewed the effects of PG on glucose metabolism, fatigue, hypertension, cardiovascular disorders, chronic obstructive pulmonary disease, renal function, cognitive function, and immune function. Our review showed some evidence for the usefulness of ginseng, which suggests that it has the potential to be used for the management of aging-related and frailty symptoms, such as fatigue and hypertension. The main limitation of this review is that no study has directly investigated the effect of PG on frailty. Instead we investigated frailty-related disorders, and the limitations of the available studies were small sample sizes and a poor methodological quality; besides, only a few studies targeted elderly people, and few included placebo controls. Larger, well-designed studies are needed to determine the effect of PG on frailty in the future.

Novel molecular mechanisms for the adaptogenic effects of herbal extracts on isolated brain cells using systems biology

INTRODUCTION

Adaptogens are natural compounds or plant extracts that increase adaptability and survival of organisms under stress. Adaptogens stimulate cellular and organismal defense systems by activating intracellular and extracellular signaling pathways and expression of stress-activated proteins and neuropeptides. The effects adaptogens on mediators of adaptive stress response and longevity signaling pathways have been reported, but their stress-protective mechanisms are still not fully understood.

AIM OF THE STUDY

The aim of this study was to identify key molecular mechanisms of adaptogenic plants traditionally used to treat stress and aging-related disorders, i.e., Rhodiola rosea, Eleutherococcus senticosus, Withania somnifera, Rhaponticum carthamoides, and Bryonia alba.

MATERIALS AND METHODS

To investigate the underlying molecular mechanisms of adaptogens, we conducted RNA sequencing to profile gene expression alterations in T98G neuroglia cells upon treatment of adaptogens and analyzed the relevance of deregulated genes to adaptive stress-response signaling pathways using in silico pathway analysis software.

RESULTS AND DISCUSSION

At least 88 of the 3516 genes regulated by adaptogens were closely associated with adaptive stress response and adaptive stress-response signaling pathways (ASRSPs), including neuronal signaling related to corticotropin-releasing hormone, cAMP-mediated, protein kinase A, and CREB; pathways related to signaling involving CXCR4, melatonin, nitric oxide synthase, GP6, Gαs, MAPK, neuroinflammation, neuropathic pain, opioids, renin-angiotensin, AMPK, calcium, and synapses; and pathways associated with dendritic cell maturation and G-coupled protein receptor-mediated nutrient sensing in enteroendocrine cells. All samples tested showed significant effects on the expression of genes encoding neurohormones CRH, GNRH, UCN, G-protein-coupled and other transmembrane receptors TLR9, PRLR, CHRNE, GP1BA, PLXNA4, a ligand-dependent nuclear receptor RORA, transmembrane channels, transcription regulators FOS, FOXO6, SCX, STAT5A, ZFPM2, ZNF396, ZNF467, protein kinases MAPK10, MAPK13, MERTK, FLT1, PRKCH, ROS1, TTN), phosphatases PTPRD, PTPRR, peptidases, metabolic enzymes, a chaperone (HSPA6), and other proteins, all of which modulate numerous life processes, playing key roles in several canonical pathways involved in defense response and regulation of homeostasis in organisms. It is for the first time we report that the molecular mechanism of actions of melatonin and plant adaptogens are alike, all adaptogens tested activated the melatonin signaling pathway by acting through two G-protein-coupled membrane receptors MT1 and MT2 and upregulation of the ligand-specific nuclear receptor RORA, which plays a role in intellectual disability, neurological disorders, retinopathy, hypertension, dyslipidemia, and cancer, which are common in aging. Furthermore, melatonin activated adaptive signaling pathways and upregulated expression of UCN, GNRH1, TLR9, GP1BA, PLXNA4, CHRM4, GPR19, VIPR2, RORA, STAT5A, ZFPM2, ZNF396, FLT1, MAPK10, MERTK, PRKCH, and TTN, which were commonly regulated by all adaptogens tested. We conclude that melatonin is an adaptation hormone playing an important role in regulation of homeostasis. Adaptogens presumably worked as eustressors ("stress-vaccines") to activate the cellular adaptive system by inducing the expression of ASRSPs, which then reciprocally protected cells from damage caused by distress. Functional investigation by interactive pathways analysis demonstrated that adaptogens activated ASRSPs associated with stress-induced and aging-related disorders such as chronic inflammation, cardiovascular health, neurodegenerative cognitive impairment, metabolic disorders, and cancer.

CONCLUSION

This study has elucidated the genome-wide effects of several adaptogenic herbal extracts in brain cells culture. These data highlight the consistent activation of ASRSPs by adaptogens in T98G neuroglia cells. The extracts affected many genes playing key roles in modulation of adaptive homeostasis, indicating their ability to modify gene expression to prevent stress-induced and aging-related disorders. Overall, this study provides a comprehensive look at the molecular mechanisms by which adaptogens exerts stress-protective effects.

Stepwise targeted matching strategy from in vitro to in vivo based on ultra-high performance liquid chromatography tandem mass spectrometry technology to quickly identify and screen pharmacodynamic constituents

The study of in vivo pharmacodynamic constituents (PCs) of traditional Chinese medicine (TCM) is important for providing new clues for TCM applications in clinical therapies in modern medicine. However, detecting and identifying PCs from complex biological samples remain a challenge. In this study, a practical and novel stepwise targeted matching and longitudinal analysis strategy from in vitro to in vivo was developed. This strategy combined with ultra-high performance liquid chromatography tandem mass spectrometry was applied to quickly discover PCs in TCM. This approach was developed based on a core perception that all drugs taken orally might be transformed progressively and orderly from the intestinal tract, liver, and blood to the target organ. Based on this core perception, stepwise targeted matching was orderly and efficiently accomplished by multiple screening processes that were based on a stepwise enriched in-house library. Ginseng (Panax ginseng) was set as the example of herbal medicine for validating the reliability and availability of this approach. By applying this novel strategy to the stepwise screening of metabolites, we successfully identified 113 metabolites, among which 59 compounds were defined as prototypes. Based on the in vivo metabolites, network pharmacology analysis was applied to screen the PCs of ginseng and clarified the action mechanism of ginseng for the treatment of Alzheimer's disease (AD). A total of 27 herbal constituents and 64 related targets shared commonly by compounds and AD were integrated via target network pharmacology analysis. These results demonstrated that this original approach will greatly improve high-throughput screening of metabolites and PCs on AD. It also can explicate the mechanism of action of TCM. Furthermore, this strategy is practicable to identify metabolites and screen PCs in other herbal medicines.

Effect of Aβ protein on inhibiting proliferation and promoting apoptosis of retinal pigment epithelial cells

AIM

To identify the effect and regulatory mechanism of amyloid β (Aβ) protein on retinal pigment epithelial (RPE) cells in cell proliferation and apoptosis, and clarify Aβ role in the pathogenesis of age-related macular degeneration (AMD).

METHODS

The model of Aβ25-35 protein cytotoxicity in RPE cell was successfully established to investigate the effect of Aβ protein on RPE cells in vitro. Based on Aβ protein, the specific inhibitors (HY-50682 or BAY11-7082) or activating agent (lipopolysaccharide) was used to analyze the regulatory mechanism of Aβ protein to RPE cells on cell proliferation and apoptosis by flow cytometry, real-time polymerase chain reaction, Western blotting, enzyme-linked immunosorbent assay and dual-luciferase reporter gene assay.

RESULTS

The number of RPE cells, treated with Aβ25-35 from 0.3 to 60 µmol/L, significantly reduce (P<0.01), and had the dose-dependent effect. Aβ protein 60 µmol/L inhibits the G1/S phase transition (P<0.01) and down-regulated cyclin E mRNA level (P<0.01). Similarly, Aβ25-35 induced a significant increase of cell apoptosis, accompanied by the significantly higher level of activated caspase 3 protein. Furthermore, nuclear factor-kappaB (NF-κB) activity and phosphorylated Iκ-Ba level would significantly lower in treated RPE cells. Using specific inhibitors or activating agent based on the Aβ, the cell numbers, NF-κB activity, phosphorylated Iκ-Ba level, receptor for advanced glycation endproducts (RAGE) gene expression levels, cyclin E mRNA level and activated caspase 3 level had accordingly changed by different methods, confirming that RAGE/NF-κB signaling pathway involved in the regulation of Aβ protein on RPE cell apoptosis and proliferation.

CONCLUSION

Aβ protein inhibits cell proliferation and activates apoptosis via inactivation of the RAGE/NF-κB signaling pathway in RPE cell.

Emerging signals modulating potential of ginseng and its active compounds focusing on neurodegenerative diseases

Common features of neurodegenerative diseases (NDDs) include progressive dysfunctions and neuronal injuries leading to deterioration in normal brain functions. At present, ginseng is one of the most frequently used natural products. Its use has a long history as a cure for various diseases because its extracts and active compounds exhibit several pharmacological properties against several disorders. However, the pathophysiology of NDDs is not fully clear, but researchers have found that various ion channels and specific signaling pathways might have contributed to the disease pathogenesis. Apart from the different pharmacological potentials, ginseng and its active compounds modulate various ion channels and specific molecular signaling pathways related to the nervous system. Here, we discuss the signal modulating potential of ginseng and its active compounds mainly focusing on those relevant to NDDs.

Tannins Enriched Fraction of Emblica officinalis Fruits Alleviates High-Salt and Cholesterol Diet-Induced Cognitive Impairment in Rats via Nrf2-ARE Pathway

Modern diets containing high quantities of salt and cholesterol have exhibited to cause a considerable effect on our health. Such diets, when consumed in the long term, have also shown to be a precursor to several disorders such as the metabolic disorder and consequently, various other diseases, including cognitive deficits. In the present study, we used a high salt and cholesterol diet (HSCD) to induce cognitive impairment in rats and also investigated the pharmacological action of tannins enriched fractions of Emblica officinalis (EOT) – a fruit that has been traditionally used for the treatment of numerous disorders for centuries. Significant alterations in MDA, GSH, TBARS, GPx, mitochondrial ATP, and mitochondrial membrane potential levels were observed in rats fed HSCD, which indicated presence of oxidative stress. Moreover, classic signs of cognitive impairment and deficits in spatial learning and memory were observed in the neurobehavioral tests. E. officinalis tannins exhibited good affinity to Nrf2 receptors in in silico studies, significantly reversed the changes in the aforementioned biomarkers of oxidative stress which were altered in the model group, as well as improved the performance of rats in Morris water maze task. Our results also reflected that EOT supplementation significantly increased the expression of Nrf2 in the CA1 region of hippocampus and cortex. Additionally, TUNEL assay indicated that EOT supplementation led to reversal of DNA fragmentation and apoptosis caused by HSCD. Immunohistochemical analysis and western blot further revealed a surge in the nuclear location of Nrf2. Through our study, we have demonstrated that cognitive impairment can be caused in rats via HSCD as a result of the oxidative stress induced by the same. Additionally, we have investigated a novel mechanism of action for EOT (which strongly suggests to be via the Nrf2–ARE pathway) and demonstrated that it has the potential to be used in the treatment of cognitive impairment.

Neuroprotective effect of formononetin in ameliorating learning and memory impairment in mouse model of Alzheimer's disease

Alzheimer's disease (AD) is the most common cause of dementia among elderly population. Deranged β-amyloid (Aβ) trafficking across the blood-brain barrier is known to be a critical element in the pathogenesis of AD. In the vascular endothelial cells of hippocampus, Aβ transport is mainly mediated by low-density lipoprotein-associated protein 1 (LRP1) and the receptor for advanced glycation end (RAGE) products; therefore, LRP1 and RAGE endothelial cells are potential therapeutic targets for AD. In this study, we explored the effects of Formononetin (FMN) on learning and memory improvement in APP/PS1 mice and the related mechanisms. We found that FMN significantly improved learning and memory ability by suppressing Aβ production from APP processing, RAGE-dependent inflammatory signaling and promoted LRP1-dependent cerebral Aβ clearance pathway. Moreover, FMN treatment alleviated ultrastructural changes in hippocampal vascular endothelial cells. In conclusion, we believe that FMN may be an efficacious and promising treatment for AD.

Beneficial effects of Panax ginseng for the treatment and prevention of neurodegenerative diseases: past findings and future directions

In recent years, several therapeutic drugs have been rationally designed and synthesized based on the novel knowledge gained from investigating the actions of biologically active chemicals derived from foods, plants, and medicinal herbs. One of the major advantages of these naturalistic chemicals is their ability to interact with multiple targets in the body resulting in a combined beneficial effect. Ginseng is a perennial herb (Araliaceae family), a species within the genus Panax, and a highly valued and popular medicinal plant. Evidence for the medicinal and health benefits of Panax ginseng and its components in preventing neurodegeneration has increased significantly in the past decade. The beneficial effects of P. ginseng on neurodegenerative diseases have been attributed primarily to the antioxidative and immunomodulatory activities of its ginsenoside components. Mechanistic studies on the neuroprotective effects of ginsenosides revealed that they act not only as antioxidants but also as modulators of intracellular neuronal signaling and metabolism, cell survival/death genes, and mitochondrial function. The goal of the present paper is to provide a brief review of recent knowledge and developments concerning the beneficial effects as well as the mechanism of action of P. ginseng and its components in the treatment and prevention of neurodegenerative diseases.

β-asarone improves learning and memory and reduces Acetyl Cholinesterase and Beta-amyloid 42 levels in APP/PS1 transgenic mice by regulating Beclin-1-dependent autophagy

Alzheimer's disease (AD) is the most common neurodegenerative disorder in the elderly, and studies have suggested that β-asarone has pharmacological effects on beta-amyloid (Aβ) injected in the rat hippocampus. However, the effect of β-asarone on autophagy in the APP/PS1 transgenic mouse is unreported. APP/PS1 transgenic mice were randomly divided into six groups (n=10/group): an untreated group, an Aricept-treated group, a 3-MA-treated group, a rapamycin-treated group, an LY294002-treated group, a β-asarone-treated group. The control group consisted of wild-type C57BL/6 mice. All treatments were administered to the mice for 30 days. Spatial learning and memory were assessed by water maze, passive avoidance, and step-down tests. AChE and Aβ₄₂ levels in the hippocampus were determined by ELISA. p-Akt, p-mTOR, and LC3B expression were detected by flow cytometry. The expression of p-Akt, p-mTOR, Beclin-1, and p62 proteins was assessed by western blot. Changes in autophagy were viewed using a transmission electron microscope. APP and Beclin-1 mRNA levels were measured by Real-Time PCR. The learning and memory of APP/PS1 transgenic mice were improved significantly after β-asarone treatment compared with the untreated group. In addition, β-asarone treatment reduced AChE and Aβ₄₂ levels, increased p-mTOR and p62 expression, decreased p-Akt, Beclin-1, and LC3B expression, decreased the number of autophagosomes and reduced APP mRNA and Beclin-1 mRNA levels compared with the untreated group. That is, β-asarone treatment can improve the learning and memory abilities of APP/PS1 transgenic mouse by inhibiting Beclin-1-dependent autophagy via the PI3K/Akt/mTOR pathway.

A Role of Ginseng and Its Constituents in the Treatment of Central Nervous System Disorders

Ginseng, a perennial plant belonging to the Panax genus of the Araliaceae family, has been used in China, Korea, and Japan as a traditional herbal medicine for thousands of years. Ginseng is recorded to have exhibited a wide variety of beneficial pharmacological effects and has become a popular and worldwide known health supplement and drug. The protective effects of ginseng on central nervous system are discussed in this review. Ginseng species and ginsenosides and their intestinal metabolism and bioavailability are concisely introduced. The molecular mechanisms of the effects of ginseng on central nervous system, mainly focused on the neuroprotection properties of ginseng, memory, and learning enhanced properties, and the effects on neurodegenerative disorders are presented. Thus, ginseng and its constituents are of potential merits in the treatment of cerebral disorders.

Salidroside suppresses inflammation in a D-galactose-induced rat model of Alzheimer's disease via SIRT1/NF-κB pathway

Age-related inflammation is the predominant factor for neurodegenerative diseases like Alzheimer's disease (AD). In the present study, we examined memory performance and neuroinflammation in D-galactose (D-gal)-induced sub-acute aging model of rats. Our results demonstrated that chronic administration of D-gal (120 mg/kg) produced cognitive impairment as determined by Morris water maze (MWM) test and step-down passive avoidance test. D-gal also activated nuclear factor kappa B (NF-κB) p65/RelA by down-regulating the expression level of sirtuins 1 (SIRT1) in the hippocampus. Treatment with Salidroside (Sal, 20, 40 mg/kg) for 28 days ameliorated D-gal-induced memory deficits and inflammatory mediators including tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). Moreover, D-gal-induced activation of NF-κB signaling pathway in the brain was also inhibited by Sal via up-regulating SIRT1. These results suggest that D-gal-triggered memory impairment and inflammatory response may be associated with SIRT1/NF-κB signaling pathway, whereas treatment with Sal could positively affect these changes in hippocampus.

A High-sugar High-fat Diet Induced Metabolic Syndrome Shows some Symptoms of Alzheimer's Disease in Rats

OBJECTIVES

Cases of sporadic Alzheimer's disease (SAD) are the predominant form of the age-related dementia. New evidence suggests that metabolic syndrome (MS), a metabolic disorder, is an initiating factor of some SAD cases. A high-sugar high-fat diet could cause MS, we aimed to investigate whether it could directly lead to SAD.

MEASUREMENTS

The characteristic molecules of AD (hippocampus Aβ and Tau) were tested by using ELISA and western blotting to confirm the happening hallmarks of AD in brain. MS and inflammation related biochemical indicators were measured using immunological method. Proteins associated with the insulin resistance signal pathway (JNK, PI-3K, AKT, GSK-3β, GLUT3) were evaluated using western blotting method. The levels of reactive oxygen species (ROS) were measured by immunofluorescence method.

RESULTS

Expressions of hippocampus Aβ, phosphorylation-Tau (p-Tau), inflammatory factors and p-JNK, Gsk-3βwere higher in the model rats than those in the control rats and expressions of p-PI3K, p-AKT and GLUT3 were reversed.

CONCLUSIONS

The MS model animals, which can induce the characteristics symptoms of AD, and therefore it may be preliminarily considered that the AD pertains to the MS-related diseases.

A UPLC/MS-based metabolomics investigation of the protective effect of ginsenosides Rg1 and Rg2 in mice with Alzheimer's disease

Background

Alzheimer's disease (AD) is a progressive brain disease, for which there is no effective drug therapy at present. Ginsenoside Rg1 (G-Rg1) and G-Rg2 have been reported to alleviate memory deterioration. However, the mechanism of their anti-AD effect has not yet been clearly elucidated.

Methods

Ultra performance liquid chromatography tandem MS (UPLC/MS)-based metabolomics was used to identify metabolites that are differentially expressed in the brains of AD mice with or without ginsenoside treatment. The cognitive function of mice and pathological changes in the brain were also assessed using the Morris water maze (MWM) and immunohistochemistry, respectively.

Results

The impaired cognitive function and increased hippocampal Aβ deposition in AD mice were ameliorated by G-Rg1 and G-Rg2. In addition, a total of 11 potential biomarkers that are associated with the metabolism of lysophosphatidylcholines (LPCs), hypoxanthine, and sphingolipids were identified in the brains of AD mice and their levels were partly restored after treatment with G-Rg1 and G-Rg2. G-Rg1 and G-Rg2 treatment influenced the levels of hypoxanthine, dihydrosphingosine, hexadecasphinganine, LPC C 16:0, and LPC C 18:0 in AD mice. Additionally, G-Rg1 treatment also influenced the levels of phytosphingosine, LPC C 13:0, LPC C 15:0, LPC C 18:1, and LPC C 18:3 in AD mice.

Conclusion

These results indicate that the improvements in cognitive function and morphological changes produced by G-Rg1 and G-Rg2 treatment are caused by regulation of related brain metabolic pathways. This will extend our understanding of the mechanisms involved in the effects of G-Rg1 and G-Rg2 on AD.