The Tao Hong Si Wu Decoction ameliorates diabetes-associated cognitive dysfunction by inhibiting the formation of amyloid plaques.

OBJECTIVES: The herbs in Tao Hong Si Wu Decoction (THSWD) are beneficial in the treatment of cognitive impairment. However, the underlying mechanisms of THSWD in treating diabetes-associated cognitive dysfunction (DACD) are not entirely explored. This study is aimed to investigate the therapeutic effects of THSWD in DACD model rats and the underlying mechanism. METHODS: Ultra-high-phase liquid chromatography was employed to identify the main compounds contained in the THSWD extract. DACD rat model was induced by feeding with a high-sugar and high-fat diet and injecting streptozotocin (35 mg/kg). DACD rats were gavaged with THSWD for 1 week. The learning and memory abilities of the rats were measured by using the Morris water maze. Western blotting was used to detect the changes in DACD rat targets. Statistical methods were used to evaluate the correlation between proteins. RESULTS: The results show that THSWD effectively reduced the escape latency, hippocampal neuron damage, glycosylated hemoglobin, type A1C, and blood lipid levels in DACD rats. Furthermore, DACD rats showed significantly increased amyloid precursor protein, ß-secretase, Aß1-40 , Aß1-42 , Tau phosphorylation, and advanced glycation end products (AGEs) expression. However, THSWD treatment can reverse this phenomenon. CONCLUSIONS: THSWD can improve the learning and memory abilities of DACD rats by inhibiting the expression of AEGs-AGE receptors pathway, which provides an experimental basis for the clinical application of THSWD. In addition, the experiment combines pharmacological and statistical methods, which offers a new perspective for the study of Chinese herbal medicine.

Catalpol rescues cognitive deficits by attenuating amyloid ß plaques and neuroinflammation.

This study sought to investigate the anti-amyloid ß (Aß) and anti-neuroinflammatory effects of catalpol in an Alzheimer's disease (AD) mouse model. METHODS: The effects of catalpol on Aß formation were investigated by thioflavin T assay. The effect of catalpol on generating inflammatory cytokines from microglial cells and the cytotoxicity of microglial cells on HT22 hippocampal cells were assessed by real-time quantitative PCR, ELISA, redox reactions, and cell viability. APPswe/PS1ΔE9 mice were treated with catalpol, and their cognitive ability was investigated using the water maze and novel object recognition tests. Immunohistochemistry and immunofluorescence were used to probe for protein markers of microglia and astrocyte, Aß deposits, and NF-κB pathway activity. Aß peptides, neuroinflammation, and nitric oxide production were examined using ELISA and redox reactions. RESULTS: Catalpol potently inhibited Aß fibril and oligomer formation. In microglial cells stimulated by Aß, catalpol alleviated the expression of the proinflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and inducible nitric oxide synthase (iNOS) but promoted the expression of the anti-inflammatory cytokine IL-10. Catalpol alleviated the cytotoxic effects of Aß-exposed microglia on HT22 cells. Treatment with catalpol in APPswe/PS1ΔE9 mice downregulated neuroinflammation production, decreased Aß deposits in the brains and alleviated cognitive impairment. Catalpol treatment decreased the number of IBA-positive microglia and GFAP-positive astrocytes and their activities of the NF-κB pathway in the hippocampus of APPswe/PS1ΔE9 mice. CONCLUSION: The administration of catalpol protected neurons by preventing neuroinflammation and Aß deposits in an AD mouse model. Therefore, catalpol may be a promising strategy for treating AD.

Alzheimer's disease: Molecular aspects and treatment opportunities using herbal drugs.

Alzheimer's disease (AD), also called senile dementia, is the most common neurological disorder. Around 50 million people, mostly of advanced age, are suffering from dementia worldwide and this is expected to reach 100-130 million between 2040 and 2050. AD is characterized by impaired glutamatergic and cholinergic neurotransmission, which is associated with clinical and pathological symptoms. AD is characterized clinically by loss of cognition and memory impairment and pathologically by senile plaques formed by Amyloid ß deposits or neurofibrillary tangles (NFT) consisting of aggregated tau proteins. Amyloid ß deposits are responsible for glutamatergic dysfunction that develops NMDA dependent Ca2+ influx into postsynaptic neurons generating slow excitotoxicity process leading to oxidative stress and finally impaired cognition and neuronal loss. Amyloid decreases acetylcholine release, synthesis and neuronal transport. The decreased levels of neurotransmitter acetylcholine, neuronal loss, tau aggregation, amyloid ß plaques, increased oxidative stress, neuroinflammation, bio-metal dyshomeostasis, autophagy, cell cycle dysregulation, mitochondrial dysfunction, and endoplasmic reticulum dysfunction are the factors responsible for the pathogenesis of AD. Acetylcholinesterase, NMDA, Glutamate, BACE1, 5HT6, and RAGE (Receptors for Advanced Glycation End products) are receptors targeted in treatment of AD. The FDA approved acetylcholinesterase inhibitors Donepezil, Galantamine and Rivastigmine and N-methyl-D-aspartate antagonist Memantine provide symptomatic relief. Different therapies such as amyloid ß therapies, tau-based therapies, neurotransmitter-based therapies, autophagy-based therapies, multi-target therapeutic strategies, and gene therapy modify the natural course of the disease. Herbal and food intake is also important as preventive strategy and recently focus has also been placed on herbal drugs for treatment. This review focuses on the molecular aspects, pathogenesis and recent studies that signifies the potential of medicinal plants and their extracts or chemical constituents for the treatment of degenerative symptoms related to AD.

A novel peptidoglycan isolated from Semiaquilegia adoxoides inhibits Aß42 production via activating autophagy.

The accumulation of amyloid ß (Aß) containing senile plaques is one of the key histopathological hallmarks of Alzheimer's disease (AD). Increasing evidences demonstrated the important role of autophagy in Aß clearance. Recent studies implied that extracts from Semiaquilegia adoxoides (DC.) Makino could ameliorate the memory of D-galactose induced aging mice. However, the bioactive substance and underlying mechanism remains unknown. Thus, the present study sought to explore the effects of a novel homogenous peptidoglycan on Aß42 secretion and the underlying mechanism. Briefly, we extracted a novel peptidoglycan named SA02C using hot water extraction and alcohol precipitation with the Mw of 13.72 kDa. SA02C contains 73.33% carbohydrate and 27.83% protein. The structure characterization revealed that its glycan part might mainly composed of galacturonic acid with minor rhamnose in backbone, and branched with glucose, galactose, arabinose, xylose and galacturonic acid. The protein or peptide moiety in SA02C was bonded to the polysaccharide via threonine. Bioactivities test showed that SA02C could reduce Aß42 production in a dose dependent manner with no obvious cytotoxicity. Mechanism study demonstrated that SA02C could modulate APP processing by upregulating the expression of ADAM10, sAPPα and downregulating BACE1, sAPPß. Furthermore, SA02C also could stimulate autophagy by promoting the expression of the markers of autophagy such as LC3B and ATG5, resulting in the promotion of Aß42 phagocytosis.

Danggui Buxue decoction ameliorates mitochondrial biogenesis and cognitive deficits through upregulating histone H4 lysine 12 acetylation in APP/PS1 mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Danggui Buxue decoction (DBD) is a classic herbal decoction consisting of Astragali Radix (AR) and Angelica Sinensis Radix (ASR) with a 5:1 wt ratio, which can supplement 'blood' and 'qi' (vital energy) for the treatment of clinical diseases. According to Traditional Chinese Medicine (TCM) theory, dementia is induced by Blood deficiency and Qi weakness, which causes a decline in cognition. However, the underlying mechanisms of DBD improving cognition deficits in neurodegenerative disease are no clear. AIM OF THE STUDY: This study aims at revealing the underlying mechanisms of DBD plays a protective role in the cognitive deficits and pathology process of Alzheimer's disease (AD). MATERIALS AND METHODS: The APP/PS1 (Mo/HuAPP695swe/PS1-dE9) double transgenic mice were adopted as an experimental model of AD. Qualitative and quantitative analysis of 3 compounds in DBT was analyzed by HPLC. Morris water maze test, Golgi staining and electrophysiology assays were used to evaluate the effects of DBD on cognitive function and synaptic plasticity in APP/PS1 mice. Western blot, immunofluorescence and Thioflavin S staining were used for the pathological evaluation of AD. Monitoring the level of ATP, mitochondrial membrane potential, SOD and MDA to evaluate the mitochondrial function, and with the usage of qPCR and CHIP for the changes of histone post-translational modification. RESULTS: In the current study, we found that DBD could effectively attenuate memory impairments and enhance long-term potentiation (LTP) with concurrent increased expression of memory-associated proteins. DBD markedly decreased Aß accumulation in APP/PS1 mice by decreasing the phosphorylation of APP at the Thr668 level but not APP, PS1 or BACE1. Further studies demonstrated that DBD restored mitochondrial biogenesis deficits and mitochondrial dysfunction. Finally, the restored mitochondrial biogenesis and cognitive deficits are under HADC2-mediated histone H4 lysine 12 (H4K12) acetylation at the peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC-1α) and N-methyl-D-aspartate receptor type 2B (GluN2B) promoters. CONCLUSIONS: These findings reveal that DBD could ameliorate mitochondrial biogenesis and cognitive deficits by improving H4K12 acetylation. DBD might be a promising complementary drug candidate for AD treatment.

Three new meroterpenoids from Sargassum macrocarpum and their inhibitory activity against amyloid ß aggregation.

Amyloid ß (Aß) is thought to be involved in the pathogenesis of Alzheimer's disease (AD). Aß aggregation in the brain is considered the cause of AD. Therefore, inhibiting Aß aggregation and degrading existing Aß aggregates is a promising approach for the treatment and prevention of the disease. In searching for inhibitors of Aß42 aggregation, we found that meroterpenoids isolated from Sargassum macrocarpum possess potent inhibitory activities. Therefore, we searched for active compounds from this brown alga and isolated 16 meroterpenoids, which contain three new compounds. The structures of these new compounds were elucidated using two-dimensional nuclear magnetic resonance techniques. Thioflavin-T assay and transmission electron microscopy were used to reveal the inhibitory activity of these compounds against Aß42 aggregation. All the isolated meroterpenoids were found to be active, and compounds with a hydroquinone structure tended to have stronger activity than those with a quinone structure.

Humulus lupulus L. Extract Protects against Senior Osteoporosis through Inhibiting Amyloid ß Deposition and Oxidative Stress in APP/PS1 Mutated Transgenic Mice and Osteoblasts

As aging progresses, ß-amyloid (Aß) deposition and the resulting oxidative damage are key causes of aging diseases such as senior osteoporosis (SOP). Humulus lupulus L. (hops) is an important medicinal plant widely used in the food, beverage and pharmaceutical industries due to its strong antioxidant ability. In this study, APP/PS1 mutated transgenic mice and Aß-injured osteoblasts were used to evaluate the protective effects of hops extracts (HLE) on SOP. Mice learning and memory levels were assessed by the Morris water maze. Mice femurs were prepared for bone micro-structures and immunohistochemistry experiments. The deposition of Aß in the hippocampus, cortex and femurs were determined by Congo red staining. Moreover, protein expressions related to antioxidant pathways were evaluated by Western blotting. It was found that HLE markedly improved learning abilities and ameliorated memory impairment of APP/PS1 mice, as well as regulated antioxidant enzymes and bone metabolism proteins in mice serum. Micro-CT tests indicated that HLE enhanced BMD and improved micro-architectural parameters of mice femur. More importantly, it was discovered that HLE significantly reduced Aß deposition both in the brain and femur. Further in vitro results showed HLE increased the bone mineralization nodule and reduced the ROS level of Aß-injured osteoblasts. Additionally, HLE increased the expression of antioxidant related proteins Nrf2, HO-1, NQO1, FoxO1 and SOD-2. These results indicated that Humulus lupulus L. extract could protect against senior osteoporosis through inhibiting Aß deposition and oxidative stress, which provides a reference for the clinical application of hops in the prevention and treatment of SOP.

Electroacupuncture Improves Blood-Brain Barrier and Hippocampal Neuroinflammation in SAMP8 Mice by Inhibiting HMGB1/TLR4 and RAGE/NADPH Signaling Pathways.

OBJECTIVE: To investigate the molecular mechanisms underlying the beneficial effect of electroacupuncture (EA) in experimental models of Alzheimer's disease (AD) in vivo. METHODS: Senescence-accelerated mouse prone 8 (SAMP8) mice were used as AD models and received EA at Yingxiang (LI 20, bilateral) and Yintang (GV 29) points for 20 days. For certain experiments, SAMP8 mice were injected intravenously with human fibrin (2 mg). The Morris water maze test was used to assess cognitive and memory abilities. The changes of tight junctions of blood-brain barrier (BBB) in mice were observed by transmission electron microscope. The expressions of fibrin, amyloid- ß (Aß), and ionized calcium-binding adapter molecule 1 (IBa-1) in mouse hippocampus (CA1/CA3) were detected by reverse transcription-quantitative polymerase chain reaction (qRT-PCR), Western blot or immunohistochemical staining. The expression of fibrin in mouse plasma was detected by enzyme-linked immunosorbent assay. The expressions of tight junction proteins zonula occludens-1 and claudin-5 in hippocampus were detected by qRT-PCR and immunofluorescence staining. Apoptosis of hippocampal neurons was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining. RESULTS: Fibrin was time-dependently deposited in the hippocampus of SAMP8 mice and this was inhibited by EA treatment (P<0.05 or P<0.01). Furthermore, EA treatment suppressed the accumulation of Aß in the hippocampus of SAMP8 mice (P<0.01), which was reversed by fibrin injection (P<0.05 or P<0.01). EA improved SAMP8 mice cognitive impairment and BBB permeability (P<0.05 or P<0.01). Moreover, EA decreased reactive oxygen species levels and neuroinflammation in the hippocampus of SAMP8 mice, which was reversed by fibrin injection (P<0.05 or P<0.01). Mechanistically, EA inhibited the promoting effect of fibrin on the high mobility group box protein 1 (HMGB1)/toll-like receptor 4 (TLR4) and receptor for advanced glycation end products (RAGE)/nicotinamide adenine dinucleotide phosphate (NADPH) signaling pathways (P<0.01). CONCLUSION: EA may potentially improve cognitive impairment in AD via inhibition of fibrin/A ß deposition and deactivation of the HMGB1/TLR4 and RAGE/NADPH signaling pathways.

rTg-D: A novel transgenic rat model of cerebral amyloid angiopathy Type-2.

Background: Cerebral amyloid angiopathy (CAA) is common disorder of the elderly, a prominent comorbidity of Alzheimer's disease, and causes vascular cognitive impairment and dementia. Previously, we generated a transgenic rat model of capillary CAA type-1 that develops many pathological features of human disease. However, a complementary rat model of larger vessel CAA type-2 disease has been lacking. Methods: A novel transgenic rat model (rTg-D) was generated that produces human familial CAA Dutch E22Q mutant amyloid ß-protein (Aß) in brain and develops larger vessel CAA type-2. Quantitative biochemical and pathological analyses were performed to characterize the progression of CAA and associated pathologies in aging rTg-D rats. Results: rTg-D rats begin to accumulate Aß in brain and develop varying levels of larger vessel CAA type-2, in the absence of capillary CAA type-1, starting around 18 months of age. Larger vessel CAA was mainly composed of the Aß40 peptide and most prominent in surface leptomeningeal/pial vessels and arterioles of the cortex and thalamus. Cerebral microbleeds and small vessel occlusions were present mostly in the thalamic region of affected rTg-D rats. In contrast to capillary CAA type-1 the amyloid deposited within the walls of larger vessels of rTg-D rats did not promote perivascular astrocyte and microglial responses or accumulate the Aß chaperone apolipoprotein E. Conclusion: Although variable in severity, the rTg-D rats specifically develop larger vessel CAA type-2 that reflects many of the pathological features of human disease and provide a new model to investigate the pathogenesis of this condition.

Chemical analysis of amyloid ß aggregation inhibitors derived from Geranium thunbergii.

Amyloid ß (Aß) aggregates in the brains of patients with Alzheimer's disease (AD) and accumulates via oligomerization and subsequent fiber elongation processes. These toxicity-induced neuronal damage and shedding processes advance AD progression. Therefore, Aß aggregation-inhibiting substances may contribute to the prevention and treatment of AD. We screened for Aß42 aggregation inhibitory activity using various plant extracts and compounds, and found high activity for a Geranium thunbergii extract (EC50 = 18 µg/mL). Therefore, we screened for Aß42 aggregation inhibitors among components of a G. thunbergii extract and investigated their chemical properties in this study. An active substance was isolated from the ethanol extract of G. thunbergii based on the Aß42 aggregation inhibitory activity as an index, and the compound was identified as geraniin (1) based on spectral data. However, although geraniin showed in vitro aggregation-inhibition activity, no binding to Aß42 was observed via saturation transfer difference-nuclear magnetic resonance (STD-NMR). In contrast, the hydrolysates gallic acid (2) and corilagin (5) showed aggregation-inhibiting activity and binding was observed via STD-NMR. Therefore, the hydrolysates produced under the conditions of the activity test may contribute to the Aß42 aggregation-inhibition activity of G. thunbergii extracts. Geraniin derivatives may help prevent and treat AD.

Targeting whole body metabolism and mitochondrial bioenergetics in the drug development for Alzheimer's disease.

Aging is by far the most prominent risk factor for Alzheimer's disease (AD), and both aging and AD are associated with apparent metabolic alterations. As developing effective therapeutic interventions to treat AD is clearly in urgent need, the impact of modulating whole-body and intracellular metabolism in preclinical models and in human patients, on disease pathogenesis, have been explored. There is also an increasing awareness of differential risk and potential targeting strategies related to biological sex, microbiome, and circadian regulation. As a major part of intracellular metabolism, mitochondrial bioenergetics, mitochondrial quality-control mechanisms, and mitochondria-linked inflammatory responses have been considered for AD therapeutic interventions. This review summarizes and highlights these efforts.

Neurotherapy of Yi-Gan-San, a Traditional Herbal Medicine, in an Alzheimer's Disease Model of Drosophila melanogaster by Alleviating Aß42 Expression.

Alzheimer's disease (AD), a main cause of dementia, is the most common neurodegenerative disease that is related to the abnormal accumulation of amyloid ß (Aß) proteins. Yi-Gan-San (YGS), a traditional herbal medicine, has been used for the management of neurodegenerative disorders and for the treatment of neurosis, insomnia and dementia. The aim of this study was to examine antioxidant capacity and cytotoxicity of YGS treatment by using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays in vitro. We explored neuroprotective effects of YGS treatment in alleviating Aß neurotoxicity of Drosophila melanogaster in vivo by comparing survival rate, climbing index, and Aß expressions through retinal green fluorescent protein (GFP) expression, highly sensitive immunomagnetic reduction (IMR) and Western blotting assays. In the in vitro study, our results showed that scavenging activities of free radical and SH-SY5Y nerve cell viability were increased significantly (p < 0.01-0.05). In the in vivo study, Aß42-expressing flies (Aß42-GFP flies) and their WT flies (mCD8-GFP flies) were used as an animal model to examine the neurotherapeutic effects of YGS treatment. Our results showed that, in comparison with those Aß42 flies under sham treatments, Aß42 flies under YGS treatments showed a greater survival rate, better climbing speed, and lower Aß42 aggregation in Drosophila brain tissue (p < 0.01). Our findings suggest that YGS should have a beneficial alternative therapy for AD and dementia via alleviating Aß neurotoxicity in the brain tissue.

Activity-differential search for amyloid-ß aggregation inhibitors using LC-MS combined with principal component analysis.

Aggregation of amyloid ß42 (Aß42) is one of the hallmarks of Alzheimer's disease (AD). Inhibition of Aß42 aggregation is thus a promising approach for AD therapy. Kampo medicine has been widely used to combat dementias such as AD. Crude drug known as Shoyaku is an ingredient of Kampo that could have potential as a natural source of novel drugs. However, given that a mixture of compounds, rather than singular compounds, could contribute to the biological functions of crude drug, there are very limited studies on the structure and mechanism of each constituent in crude drug which may have anti-Aß42 aggregation properties. Herein we provide an efficient method, using LC-MS combined with principal component analysis (PCA), to search for activity-dependent compounds that inhibit Aß42 aggregation from 46 crude drug extracts originating from 18 plants. Only 5 extracts (Kakou, Kayou, Gusetsu, Rensu, and Renbou) from lotus demonstrated differentially inhibitory activities depending on the part of the plant from which they are derived (e.g. petiole, leaf, root node, stamen, and receptacle, respectively). To compare the anti-aggregative properties of compounds of active crude drug with those of inactive crude drug, these extracts were subjected to LC-MS measurement, followed by PCA. From 12 candidate compounds identified from the analysis, glucuronized and glucosidized quercetin, as well as 6 flavonoids (datiscetin, kaempferol, morin, robinetin, quercetin, and myricitrin), including catechol or flatness moiety suppressed Aß42 aggregation, whereas curcumol, a sesquiterpene, did not. In conclusion, this study offers a new activity-differential methodology to identify bioactive natural products in crude drugs that inhibit Aß42 aggregation and that could be applied to future AD therapies.

Effects of Perilla frutescens var. acuta in amyloid ß toxicity and Alzheimer's disease-like pathology in 5XFAD mice.

Although accumulation of amyloid ß (Aß) plaque is a major hallmark of Alzheimer's disease (AD), various pathologies have been suggested therapeutic targets. Therefore, therapies-targeting multiple pathologies would be required for effective managements of AD. Accordingly, natural products, which has multiple active ingredients, have been receiving a lot of attention. In this study, we tested whether standardized ethanol extract of leaves of Perilla frutescens var. acuta (L.) Britt. (Lamiaceae) (ELPF) could modulate various pathologies in AD using 5XFAD mice. ELPF blocked Aß aggregation and disassembled pre-formed Aß aggregates. ELPF blocked Aß aggregates-induced LTP impairment and ELPF-disassembled Aß aggregates failed to impair hippocampal LTP. Systemic administration of ELPF blocked Aß aggregates-induced memory impairment in a passive avoidance test. ELPF-disassembled Aß aggregates failed to impair passive avoidance memory. Prolonged administration of ELPF ameliorated memory impairments in 5XFAD mice. In the hippocampus of 5XFAD mice, ELPF administration significantly reduced Aß deposits and neuroinflammation. These results demonstrate that ELPF could be a promising therapeutic candidate for AD.

Optimal Formula of Angelica sinensis Ameliorates Memory Deficits in ß-amyloid Protein-induced Alzheimer's Disease Rat Model.

OBJECTIVE: Angelica (A.) sinensis is used as a traditional medical herb for the treatment of neurodegeneration, aging, and inflammation in Asia. A. sinensis optimal formula (AOF) is the best combination in A. sinensis that has been screened to rescue the cognitive ability in ß-amyloid peptide (Aß25-35)-treated Alzheimer's disease (AD) rats. The objective of this study was to investigate the effect of AOF on the learning and memory of AD rats as well as to explore the underlying mechanisms. METHODS: Male Wistar rats were infused with Aß25-35 for AD model induction or saline (negative control). Five groups of AD rats were fed on AOF at 20, 40, or 80 mL/kg every day, donepezil at 0.9 mg/kg every day (positive control), or an equal volume of water (AD model) intragastrically once a day for 4 weeks, while the negative control rats were fed on water. The Morris water maze test was used to evaluate the cognitive function of the rats. The Aß accumulation, cholinergic levels, and antioxidative ability were detected by ELISA. Additionally, the candidate mechanism was determined by gene sequencing and quantitative real-time polymerase chain reaction. RESULTS: The results showed that AOF administration significantly ameliorated Aß25-35-induced memory impairment. AOF decreased the levels of amyloid-ß precursor protein and Aß in the hippocampus, rescued the cholinergic levels, increased the activity of superoxide dismutase, and decreased the malondialdehyde level. In addition, AOF inhibited the expression of IL1b, Mpo, and Prkcg in the hippocampus. CONCLUSION: These experimental findings illustrate that AOF prevents the decrease in cognitive function and Aß deposits in Aß25-35-treated rats via modulating neuroinflammation and oxidative stress, thus highlighting a potential therapeutic avenue to promote the co-administration of formulas that act on different nodes to maximize beneficial effects and minimize negative side effects.

Combination of Ocimum sanctum extract and Levetiracetam ameliorates cognitive dysfunction and hippocampal architecture in rat model of Alzheimer's disease.

Alzheimer's disease (AD) is the most common neurodegenerative disease which affects more than 40 million people worldwide with progressive loss of memory and cognitive functions. It is reported, persistent AD is also one of the main causes of epilepsy in elders and comorbidity of both these will contribute to worsening the health status of AD patients. Recently, herbal plants with potent neuroprotective and antioxidant properties were used for increasing the quality of life in neurodegenerative disease patients. The present study was conceptualized to access the protective effect of Ocimum sanctum extract (OSE) and Levetiracetam (LEV) and their combination (OSE+LEV) against AD and epilepsy associated with AD in the rat AD model. AD was induced in aged male Wistar albino rats with Amyloid-ß (Aß) by intracerebroventricular administration. The results reveal, treatment with OSE, LEV and OSE+LEV significantly reversed the memory impairment, increases the BDNF expressions and decreases AChE activity in Aß induced AD animals. Expression of A-ß and p-tau in the hippocampus was significantly reduced in treatment group when compared to the control animals. Treatment with OSE and OSE+LEV also restored the hippocampal architecture by ameliorating the neuronal count in CA1, CA3 and DG regions. It also observed that treatment has decreased the excitoneurotoxicity evidenced by decreased glutamate and increased GABA levels and thus provided protection against epilepsy. Treatment groups also exhibited a potent antioxidant activity when tested endogenous antioxidant enzymes SOD, GSH and LPO in the brain hippocampus. Our findings provide evidence for use of OSE, LEV and OSE+LEV against AD and epilepsy associated with AD in Aß induced AD animal model. However, further clinical studies are required to prove the use of OSE, LEV and OSE+LEV in the management of AD and AD-associated epilepsy in human volunteers.

Black phosphorous quantum dots for signal-on cathodic photoelectrochemical aptasensor monoitoring amyloid ß peptide.

In this paper, a quantitative cathodic photoelectrochemical aptasensor is described by using black phosphorous quantum dots (BPQDs) as photoactive material and assisted by heme as electron acceptor for sensing of amyloid ß peptide (Aß). Specifically, BPQDs were synthesized by solvothermal method and characterized by various techniques. The as-prepared BPQDs were assembled on the transparent indium tin oxide electrode, and the positively charged poly-l-lysine (PLL) was then absorbed onto BPQDs via electronic interaction. Subsequently, the aptamer as the specific recognition element for Aß oligomer was introduced on the BPQDs-PLL modified electrode. After bound with heme to form Aß-heme complex, Aß oligomer was simultaneously captured by the aptamer on the electrode, resulting in an enhanced photocurrent response. Under the optimized conditions, the present PEC sensor reveals a good linear response to Aß peptide ranging from 1.0 fM to 100 nM with a detection limit of 0.87 fM. The present signal-on cathodic PEC bioassay possesses the potential to create a new paradigm in amplified PEC assays that could provide outstanding performance for bioanalysis.

Anti-Alzheimer's disease potential of Arabian coffee versus Date palm seed extract in male rats.

Coffee is among the most commonly consumed beverage all over the world. Studies have increasingly suggested caffeine and coffee as effective therapeutic interventions against Alzheimer's disease (AD). We have therefore utilized the aluminum chloride rat model for AD to compare the influence of moderately caffeinated (Arabian) and decaffeinated (Date palm seed) coffee on cognitive impairment and pathological events in AD. AD rats given Arabian or Date palm seed coffee were protected against memory impairment and had lower serum levels of the abnormal protein (amyloid-beta; Aß1-42), the central pathogenic contributor to AD, and transforming growth factor-beta (TGF-ß). Interestingly, Date palm seed (decaffeinated) coffee seems to provide more pronounced protection against AD than Arabian (moderately caffeinated) coffee as evidenced by the greater decrease in serum Aß levels. These results suggest a surprising therapeutic potential of moderate caffeine intake in Arabian coffee to ameliorate AD through decreasing serum Aß levels. However, Date palm seed (decaffeinated) coffee, rich in flavonoids, appears to provide a better AD-modifying ability through a direct reduction of Aß production. PRACTICAL APPLICATIONS: Consumption of moderately caffeinated Arabian coffee attenuated AD-induced cognitive impairment via its anti-amyloidogenic potential, decreasing Aß levels. Moreover, intake of decaffeinated Date seed extract, rich in flavonoids, exerted a superior anti-AD potential through a direct reduction of Aß production. Both of them were also safe and maintained hepatic and renal functions in a rat model of AlCl3 -induced AD. Further clinical studies are warranted to confirm current results and to recommend the regular drinking of Arabian coffee or Date seed extract as a protective approach to delay AD progression in vulnerable individuals or in early disease stages.

Panax notoginseng saponins protect PC12 cells against Aß induced injury via promoting parkin-mediated mitophagy.

ETHNOPHARMACOLOGICAL RELEVANCE: Panax notoginseng (Burk) F. H. Chen is a well-known traditional Chinese medicine with a long history and is widely used in the treatment of cerebrovascular disease. Panax notoginseng saponins (PNS) are the main active ingredients in Panax notoginseng (Burk) F. H. Chen, and its injection is used to treat nerve damage caused by cerebral ischemia and other conditions. PNS is thought to alleviate cognitive impairment in patients with Alzheimer's disease; however, its mechanism of action is unclear. AIM OF THE STUDY: We elucidated the role of PNS in attenuating cellular mitochondrial damage caused by amyloid ß (Aß) protein and in protecting cell viability from the perspective of regulating autophagy. By investigating the effects of PNS on the targets regulating mitophagy, we wanted to reveal the autophagy related mechanism by which PNS attenuated Aß damage in neuronal cells. MATERIALS AND METHODS: The effect of PNS on the mitochondrial membrane potential of Aß-injured PC12 cells was detected using flow cytometry, which reflected the alleviating effect of PNS on mitochondrial damage. Using mRFP-GFP-LC3-transfected PC12 cells, the effect of PNS on cellular autophagy flux was observed using laser confocal microscopy. Formation of the intracellular autophagosome was observed using transmission electron microscopy, which reflected the activation of autophagy by PNS. The siPINK1 lentivirus was used to silence the PINK1 gene in PC12 cells to obtain siPINK1-PC12 cells. The effects of PNS on the expression of the PINK1 gene and on the autophagy-related proteins LC3II/Ⅰ, p62, PINK1, parkin, NDP52, and OPTN were observed to reveal the possible targets of PNS in regulating autophagy. RESULTS: After PNS treatment, the viability of Aß-injured PC12 cells improved and the mitochondrial membrane potential was restored. PNS treatment significantly enhanced the autophagy flux of damaged cells and increased the levels of LC3II/Ⅰ protein and decreased p62 protein, while significantly improving the structure and mitochondrial morphology of PC12 cells injured by Aß. These changes led to more autophagosomes wrapping around the damaged mitochondria and promoting the depletion of OPTN, a mitophagy receptor. After silencing the PINK1 gene, PNS could not alter the PINK1 gene and protein levels, but could still increase LC3II/Ⅰ, decrease p62 and OPTN, and significantly increase the amount of parkin. CONCLUSIONS: PNS could enhance the autophagic activity of cells, alleviate mitochondrial damage caused by Aß injury, and protect the activity of PC12 cells. It is possible that enhanced autophagy was achieved by promoting the recruitment of parkin protein to the mitochondrial receptors in a non-PINK1-dependent manner.

Oat Extract Avenanthramide-C Reverses Hippocampal Long-Term Potentiation Decline in Tg2576 Mice.

Memory deterioration in Alzheimer's disease (AD) is thought to be underpinned by aberrant amyloid ß (Aß) accumulation, which contributes to synaptic plasticity impairment. Avenanthramide-C (Avn-C), a polyphenol compound found predominantly in oats, has a range of biological properties. Herein, we performed methanolic extraction of the Avns-rich fraction (Fr. 2) from germinated oats using column chromatography, and examined the effects of Avn-C on synaptic correlates of memory in a mouse model of AD. Avn-C was identified in Fr. 2 based on 1H-NMR analysis. Electrophysiological recordings were performed to examine the effects of Avn-C on the hippocampal long-term potentiation (LTP) in a Tg2576 mouse model of AD. Avn-C from germinated oats restored impaired LTP in Tg2576 mouse hippocampal slices. Furthermore, Avn-C-facilitated LTP was associated with changes in the protein levels of phospho-glycogen synthase kinase-3ß (p-GSK3ß-S9) and cleaved caspase 3, which are involved in Aß-induced synaptic impairment. Our findings suggest that the Avn-C extract from germinated oats may be beneficial for AD-related synaptic plasticity impairment and memory decline.