Vitamin-D as a multifunctional molecule for overall well-being: An integrative review.

Vitamin D is amongst the most important biomolecules to regularize and help in sustainable health, however, based on the studies, deficiency of this multifunctional vitamin is common. Vitamin D, besides playing a role in the form of vitamins, also acts as a multifunctional hormone (steroid). Vitamin D is synthesized inside the body through various steps starting from ultraviolet radiation exposure and comes from limited food sources, however, vitamin D-fortified food products are still among the major sources of vitamin D. Current review, focused on how vitamin D acts as a multifunctional molecule by effecting different functions in the body in normal or specific conditions and how it is important in fortification and how it can be managed from the available literature till date. During the Covid pandemic, people were aware of vitamin D and took supplementation, fortified foods, and sat under sunlight. As COVID prevalence decreases, people start forgetting about vitamin D. Vitamin D is very crucial for overall well-being as it has protective effects against a broad range of diseases as it can reduce inflammation, cancer cell growth and helps in controlling infection, increase metabolism, muscle, and bone strength, neurotransmitter expression, etc. Therefore, the present review is to provoke the population, and fulfillment of the vitamin D recommended dietary allowance daily must be confirmed.

The Utilisation of Mushroom Leftovers, Oats, and Lactose-Free Milk Powder for the Development of Geriatric Formulation.

This study aims to focus on developing a food supplement for the geriatric population using disposal mushrooms, oats, and lactose-free milk powder. Lactose intolerance is most common in older adults, raising the demand for lactose-free foods. One of the major global challenges currently faced by humankind is food waste (FW). Most of the food that is produced for human consumption has not been utilized completely (1/3rd-1/2 unutilized), resulting in agricultural food waste. Mushrooms are highly valuable in terms of their nutritional value and medicinal properties; however, a significant percentage of mushroom leftovers are produced during mushroom production that do not meet retailers' standards (deformation of caps/stalks) and are left unattended. Oats are rich in dietary fibre beta-glucan (55% water soluble; 45% water insoluble). Lactose-free milk powder, oats, and dried mushroom leftover powder were blended in different ratios. It was observed that increasing the amount of mushroom leftover powder increases the protein content while diluting calories. The product with 15% mushroom powder and 30% oat powder showed the highest sensory scores and the lowest microbial count. The GCMS and FTIR analyses confirmed the presence of ergosterol and other functional groups. The results of the XRD analysis showed that the product with 15% mushroom powder and 30% oat powder had a less crystalline structure than the product with 5% mushroom powder and 40% oat powder and the product with 10% mushroom powder and 35% oat powder, resulting in more solubility. The ICP-OES analysis showed significant concentrations of calcium, potassium, magnesium, sodium, and zinc. The coliform count was nil for the products, and the bacterial count was below the limited range (3 × 102 cfu/g). The product with 15% mushroom powder and 30% oat powder showed the best results, so this developed product is recommended for older adults.

Types of memory, dementia, Alzheimer's disease, and their various pathological cascades as targets for potential pharmacological drugs.

Alzheimer's disease (AD) is the most common type of dementia accounting for 90% of cases; however, frontotemporal dementia, vascular dementia, etc. prevails only in a minority of populations. The term dementia is defined as loss of memory which further takes several other categories of memories like working memory, spatial memory, fear memory, and long-term, and short-term memory into consideration. In this review, these memories have critically been elaborated based on context, duration, events, appearance, intensity, etc. The most important part and purpose of the review is the various pathological cascades as well as molecular levels of targets of AD, which have extracellular amyloid plaques and intracellular hyperphosphorylated tau protein as major disease hallmarks. There is another phenomenon that either leads to or arises from the above-mentioned hallmarks, such as oxidative stress, mitochondrial dysfunction, neuroinflammation, cholinergic dysfunction, and insulin resistance. Several potential drugs like antioxidants, anti-inflammatory drugs, acetylcholinesterase inhibitors, insulin mimetics or sensitizers, etc. studied in various previous preclinical or clinical reports were put as having the capacity to act on these pathological targets. Additionally, agents directly or indirectly targeting amyloid and tau were also discussed. This could be further investigated in future research.

Impact of COVID-19 on Brain and Psychological Health, its Possible Mechanisms, and Coping Strategies.

COVID-19 pandemic has been depicted to possess a robust association with psychological disorders. SARS-CoV-2 is the most recent virus of the coronavirus family and has the potential to bind the angiotensin-converting enzyme (ACE) receptor. The receptor is mainly present peripherally and to some extent in the brain. Different psychological and neurodegenerative disorders can arise due to the peripheral origin of destruction. These triggers could be inflammatory pathways releasing pro-inflammatory cytokines reaching the brain and causing neuroinflammation. In continuation with traditional viruses, SARS-CoV-2 too might lead to brain diseases like meningitis, encephalitis, etc. Besides, several peripheral hormonal changes like cortisol can influence neurochemical alterations, thereby inflicting mood-related activities and psychological phenomena. In this regard, health care workers, frontline line warriors and relatives of COVID-19 patients can be the secondary victims; however, patients with COVID-19 remain the primary ones prone to neurological health problems. Several strategies like socialization, engagement, physical activity, etc., are well-opted measures to get relief from and check psychiatric disturbances. The worth of this review can be attributed to the understanding of brain-related mechanisms of COVID-19 in the context of its mechanism of action to create the pathology pertaining to brain disorder, precisely psychological devastation. Likewise, its epidemiological relevance has concisely been mentioned. Furthermore, different categories and classes of people prone to psychological deterioration are briefly elaborated on. Lastly, some coping strategies and approaches have been discussed to minimize or combat mental health problems.

Sarcosine (glycine transporter inhibitor) attenuates behavioural and biochemical changes induced by ketamine, in the rat model of schizophrenia.

Schizophrenia is a neurological disorder that alters the behavior and affects the quality of life of a patient. It is characterized by hallucinations, disorganized behavior, cognitive dysfunction, hyperlocomotion, and loss of the reward system. Schizophrenia constitutes three symptoms' domains, viz. positive, negative and cognitive. Typical and atypical antipsychotics do not fully resolve all the symptoms' domains thus paving the way to the genesis of the glutamatergic hypothesis, i.e. N-methyl-D-aspartate (NMDA) receptor hypofunction in the pathophysiology of schizophrenia. Positive modulation of NMDA receptors by enhancing co-agonist, glycine effect is proposed to produce a therapeutic effect in schizophrenia. Hence, sarcosine (N-methyl glycine), natural amino acid, and a glycine transporter inhibitor (GlyT-1) which also acts on NMDA receptors were used in the present study. The present study unravels the role of sarcosine in the attenuation of ketamine-induced three symptom domains in a rat model through modulation of oxidative stress, mitochondrial dysfunction, and neuroinflammatory pathways. The animal model of schizophrenia was established by injecting ketamine intraperitoneal (ip) at a 30 mg/kg dose for 10 consecutive days, after which sarcosine (300, 600 mg/kg, ip) as a treatment was given for 7 days followed by behavioral, biochemical, molecular, and histopathological analysis. It was revealed that sarcosine reversed ketamine-induced behavioral impairments. Moreover, sarcosine ameliorated oxidative and nitrosative stress, mitochondrial dysfunction, and neuroinflammation and showed protective effects in histopathological examination by hematoxylin and eosin staining. Hence, conclusively, sarcosine was regarded to attenuate the behavioural symptoms of schizophrenia by alleviating oxidative stress, neuroinflammation, and mitochondrial dysfunction established by the ketamine.

Synthesis of deoxy-Andrographolide Triazolyl Glycoconjugates for the Treatment of Alzheimer's Disease.

A new andrographolide-based terminal alkyne 3 was synthesized in good yield from deoxy-andrographolide 2, obtained from a natural compound andrographolide 1, which in turn was isolated from the leaves of the plant Andrographis paniculata. Copper(I)-catalyzed azide-alkyne cycloaddition reaction of alkyne 3 with azido-sugars 4a-f furnished a library of andrographolide-fastened triazolyl glycoconjugates 5a-f in good yields. The structures of these semisynthetic andrographolide derivatives were established by Fourier transform infrared, NMR, and mass spectroscopy. The compounds 5a-f were further evaluated against Alzheimer's disease (AD) using a scopolamine (SCOP)-induced memory impairment mice model. It was observed that antioxidant and anticholinesterase properties of these compounds contribute significantly toward their remarkable potential to improve cognitive functioning.

Anti-inflammatory effects of ellagic acid and vanillic acid against quinolinic acid-induced rat model of Huntington's disease by targeting IKK-NF-κB pathway.

Huntington disease (HD), an autosomal dominant neurodegenerative disorder characterized by involuntary choreatic movements with cognitive and behavioral disturbances. HD striatum has increased conversion of kynurenine to quinolinic acid (QA) which activates NMDA receptors leading to activation of microglia and increased levels of nuclear factor kappa B (NF-κB) leading to elevated transcription of inducible nitric oxide synthase (iNOS) and various cytokines causing neuronal death via neuroinflammation, oxidative stress, mitochondrial dysfunction and apoptosis. Therefore, inhibiting IKK-NF-κB pathway induced excitotoxicity, oxidative stress and neuroinflammation could be a potential intervention in slowing down the disease progression. QA injection intrastriatally (IS-QA) produce damage mimicking HD where neuroinflammation, oxidative stress and mitochondrial dysfunction play crucial role. Ellagic acid (EA) and vanillic acid (VA) are well reported to possess antioxidant and NF-κB inhibiting effect. Hence, in present study, rats administered IS-QA were treated with EA and VA for 21 days to explore their neuroprotective effects. Behavioral studies, biochemical estimations for oxidative stress and acetylcholinesterase assay were performed. Mitochondrial function was determined by estimating mitochondrial enzyme complexes; inflammatory markers like TNF-α, IL-6, NF-κB by ELISA and apoptosis by caspase-3 levels. Brain damage was determined by histopathology which revealed their neuroprotective effects. Various doses of EA and VA produced improved motor and cognitive functions, oxidative stress and neuroinflammation were also reduced and mitochondrial functioning was improved. In a nutshell, these results signify improved motor and cognitive functions by EA and VA in QA model of HD, along with declined oxidative stress, mitochondrial dysfunction and neuroinflammation.

Tetramethylpyrazine Attenuates Cognitive Impairment Via Suppressing Oxidative Stress, Neuroinflammation, and Apoptosis in Type 2 Diabetic Rats.

Cognitive dysfunction is an important complication observed in type 2 diabetes mellitus (T2DM) patients. Tetramethylpyrazine (TMP) is known to exhibit anti-diabetic and neuroprotective properties. Therefore, the present study aimed to investigate the possible therapeutic effects of TMP against type 2 diabetes-associated cognitive impairment in rats. High-fat diet (HFD) followed by a low dose of streptozotocin (35 mg/kg) was used to induce diabetes in Sprague-Dawley rats. TMP (20, 40, and 80 mg/kg) and Pioglitazone (10 mg/kg) were administered for 4 weeks. The Morris water maze (MWM) and novel objective recognition task (NOR) tests were used to assess memory function. Fasting blood glucose (FBG), lipid profile, HOMA-IR, glycosylated hemoglobin (HbA1c), and glucose tolerance were measured. Acetylcholinesterase (AChE) and choline acetytransferase (ChAT) activity, acetylcholine (ACh) levels, oxidative stress, apoptotic (Bcl-2, Bax, caspase-3), and inflammatory markers (TNF-α, IL-1ß, and NF-kß) were assessed. BDNF, p-AKT, and p-CREB levels were also measured. In the present work, we observed that treatment of diabetic rats with TMP alleviated learning and memory deficits, improved insulin sensitivity, and attenuated hyperglycemia and dyslipidemia. Furthermore, treatment with TMP increased BDNF, p-Akt, and p-CREB levels, normalized cholinergic dysfunction, and suppressed oxidative, inflammatory, and apoptotic markers in the hippocampus. Collectively, our results suggest that the TMP may be an effective neuroprotective agent in alleviating type 2 diabetes-associated cognitive deficits.

Protective Effects of Zingerone Against Depression-Like Behavior and Biochemical Changes in Chronic Stressed Rats: Antioxidant Effects.

Ginger contains zingerone, an active constituent possessing antioxidant and neuroprotective properties. The present study was designed to explore the efficacy of the bioactive compound, zingerone, for treating behavioral and biochemical alterations in rats exposed to chronic restraint stress (CRS). Female Wistar rats were administered zingerone (25, 50, and 100 mg/kg p.o.) once daily for a period of 28 days while being exposed to CRS (6 h/day). Our results indicated that the stressed animals depicted depression-like behavior (reduced sucrose preference and increased immobility time) associated with increased lipid peroxidation (LPO) (cortex), decreased catalase (CAT) (hippocampus and cortex), and increased superoxide dismutase (SOD) (hippocampus and cortex). In addition, metabolic alterations were characterized by hyperglycemia and increased glycosylated hemoglobin in the CRS rats. However, no alterations were observed for learning and memory and in the levels of reduced glutathione. Repeated zingerone administration significantly reversed depression-like behavior elicited by CRS in rats. Furthermore, a significant antioxidant effect was exhibited by zingerone, as shown by decreased LPO and enhanced activity of SOD and CAT in chronically stressed rats. The findings of our study demonstrated that zingerone possesses protective actions against chronic stress-induced depressive-like behavioral, biochemical, and metabolic alterations and that its underlying mechanism may be attributed to its antioxidant properties. The results also signify its pharmacological and possible nutritional importance.

Antidepressant-like effect of sodium orthovanadate in a mouse model of chronic unpredictable mild stress.

Depression is a psychiatric disorder characterized by low-esteem, anhedonia, social deficit, and lack of interest. Decreased brain-derived neurotrophic factor (BDNF) and impaired tropomyosin kinase B receptor (TrkB receptor) signaling are associated with depression. In our study, depressive-like behavior was induced in mice by chronic unpredictable mild stress (CUMS) model. Various behavioral tests like tail suspension test (TST), open field test (OFT), sucrose preference test (SPT); biochemical analyses for corticosterone, reduced glutathione (GSH), lipid peroxidation (LPO), superoxide dismutase (SOD), nitric oxide (NO) and enzyme-linked immunosorbent assay (ELISA) for BDNF were performed. Body weight was measured every week. CUMS induced depressive-like behavior was found to be associated with increased oxidative stress in the brain and serum corticisterone with subsequent reduction of BDNF. Sodium orthovanadate (SOV), a protein tyrosine phosphatase inhibitor already reported to elevate BDNF levels, was used as the test drug. Sodium orthovanadate (5 mg/kg, 10 mg/kg) and fluoxetine (FLX-10 mg/kg) was given to mice orally for 21days before 30 min of stress induction. The behavioral tests reflected depressive-like behavior in CUMS, which was attenuated by both SOV and fluoxetine. SOV at 10 mg/kg demonstrated significant results in the present study characterized by decreased malondialdehyde levels (MDA/LPO), NO levels, and increased GSH level and SOD activity in both the cortex and hippocampus. Besides, ELISA has revealed the significant elevation of BDNF levels in the treatment groups (SOV-5 mg/kg, 10 mg/kg and FLX-10 mg/kg) as compared to the disease group (CUMS). Therefore, the treatment with SOV appeared to reverse both oxidative and nitrosative stress. Decreased serum corticosterone levels observed with SOV (5 & 10 mg/kg), FLX-10 mg/kg, FLX (10 mg/kg) + SOV (5 mg/kg); and SOV-10 mg/kg per-se treatment and elevated BDNF level with SOV (5 & 10 mg/kg), FLX-10 mg/kg were associated with attenuation of depressive-like behavior. The findings of this preliminary study indicate that SOV has the potential to restore antidepressant-like effects or prevent stress-induced anhedonia and so further molecular mechanisms are warranted for clinical translation.

Preclinical Models for Alzheimer's Disease: Past, Present, and Future Approaches.

A robust preclinical disease model is a primary requirement to understand the underlying mechanisms, signaling pathways, and drug screening for human diseases. Although various preclinical models are available for several diseases, clinical models for Alzheimer's disease (AD) remain underdeveloped and inaccurate. The pathophysiology of AD mainly includes the presence of amyloid plaques and neurofibrillary tangles (NFT). Furthermore, neuroinflammation and free radical generation also contribute to AD. Currently, there is a wide gap in scientific approaches to preventing AD progression. Most of the available drugs are limited to symptomatic relief and improve deteriorating cognitive functions. To mimic the pathogenesis of human AD, animal models like 3XTg-AD and 5XFAD are the primarily used mice models in AD therapeutics. Animal models for AD include intracerebroventricular-streptozotocin (ICV-STZ), amyloid beta-induced, colchicine-induced, etc., focusing on parameters such as cognitive decline and dementia. Unfortunately, the translational rate of the potential drug candidates in clinical trials is poor due to limitations in imitating human AD pathology in animal models. Therefore, the available preclinical models possess a gap in AD modeling. This paper presents an outline that critically assesses the applicability and limitations of the current approaches in disease modeling for AD. Also, we attempted to provide key suggestions for the best-fit model to evaluate potential therapies, which might improve therapy translation from preclinical studies to patients with AD.

Advances in the pharmacotherapeutic management of post-traumatic stress disorder.

Introduction: Post-traumatic stress disorder (PTSD), a mental disorder, is associated with anxiety, depression, and social awkwardness resulting from past traumatic episodes like natural disasters, accidents, terrorist attacks, war, rape, and sexual violence. It affects primarily the amygdala, cortex, and hippocampus where neurochemical changes result in altered behavior. PTSD patients display impaired fear extinction, and past events keep haunting them. The topic presents relevant sections like PTSD pharmacotherapy, associated challenges, and the novel targets and drugs for future research and therapy.Areas covered: The authors discuss the current pharmacotherapy like SSRIs, NDRIs, SNRIs, anticonvulsants, antidepressants, and benzodiazepines, used to attenuate the associated symptoms. However, the primary focus being the novel and potential targets which can be explored better to understand possible future research and advanced therapy in PTSD. For the same, an account of both preclinical and clinical studies has been covered.Expert opinion: Excessive adverse effects, limited efficacy, and lower patient compliance are some of the major challenges with conventional drugs. Moreover, they correct only fewer symptoms without halting the disease progression. Several agents are investigated in different preclinical and clinical phases, which can potentially overcome the pitfalls and limitations associated with conventional therapies.

7,8-Dihydroxyflavone improves cognitive functions in ICV-STZ rat model of sporadic Alzheimer's disease by reversing oxidative stress, mitochondrial dysfunction, and insulin resistance.

RATIONALE: Intracerebroventricular (ICV) streptozotocin (STZ) mimics sporadic Alzheimer's disease (SAD) characterized by tau pathology and neurodegeneration arising from oxidative stress, mitochondrial dysfunction, and insulin resistance. 7,8-Dihydroxyflavone (7,8-DHF) is a flavonoid having antioxidant property interlinked with mitochondrial functioning and insulin actions. OBJECTIVES: To evaluate the neuroprotective and cognitive enhancement properties of 7,8-DHF in an ICV-STZ rat model of SAD. METHODS: ICV-STZ (3 mg/kg) was injected into male Wistar rats. Cognitive functions were evaluated by Morris water maze (MWM) and novel object recognition (NOR). 7,8-DHF (5 mg/kg, 10 mg/kg, and 20 mg/kg) and rivastigmine (2 mg/kg) were given orally for 21 days. Reduced glutathione (GSH), catalase, superoxide dismutase (SOD), glutathione peroxidase (GPX), lipid peroxidation (LPO), protein carbonylation (PCO), and nitrite assays were performed. Mitochondrial enzyme complex I, II, III, and IV, and acetylcholinesterase (AchE) activities were determined. ELISA for the insulin-degrading enzyme (IDE) and p-tau was done. Histopathology was investigated by hematoxylin and eosin staining. RESULTS: 7,8-DHF treatment attenuated ICV-STZ-induced cognitive deficit in MWM and NOR. Moreover, in the cortex and hippocampus regions of the brain, GSH, catalase, SOD, GPX, LPO, PCO, and nitrite levels were reversed. Mitochondrial enzyme complex I, II, III, and IV, and acetylcholinesterase (AchE) activities were also normalized. IDE and p-tau protein were found to be significantly altered. 7,8-DHF provided protection from neuronal cell death examined in histopathology. CONCLUSIONS: Conclusively, 7,8-DHF was found to be neuroprotective in the ICV-STZ rat model by ameliorating oxidative stress, mitochondrial dysfunction, and insulin resistance, thereby improving cognitive functions evident with the behavioral results.

Neuroprotective effects of roflumilast against quinolinic acid-induced rat model of Huntington's disease through inhibition of NF-κB mediated neuroinflammatory markers and activation of cAMP/CREB/BDNF signaling pathway.

Huntington's disease (HD) is a progressive neurodegenerative and hyperkinetic movement disorder. Decreased activity of cAMP-responsive element-binding protein (CREB) is thought to contribute to the death of striatal medium spiny neurons in HD. The present study has been designed to explore the possible role of roflumilast against qunilonic acid (QA) induced neurotoxicity in rats intending to investigate whether it inhibits the neuroinflammatory response through activation of the cAMP/CREB/BDNF signaling pathway. QA was microinjected (200 nmol/2 µl, bilaterally) through the intrastriatal route in the stereotaxic apparatus. Roflumilast (0.5, 1, and 2 mg/kg, orally) once-daily treatment for 21 days significantly improved locomotor activity in actophotometer, motor coordination in rotarod, and impaired gait performance in narrow beam walk test. Moreover, roflumilast treatment significantly attenuated oxidative and nitrosative stress (p < 0.05) through attenuating lipid peroxidation nitrite concentration and enhancing reduced glutathione, superoxide dismutase, and catalase levels. Furthermore, roflumilast also significantly decreased elevated pro-inflammatory cytokines like TNF-α (p < 0.01), IL-6 (p < 0.01), IFN-γ (p < 0.05), NF-κB (p < 0.05) and significantly increased BDNF(p < 0.05) in the striatum and cortex of rat brain. The results further demonstrated that roflumilast effectively increased the gene expression of cAMP(p < 0.05), CREB(p < 0.05) and decreased the gene expression of PDE4 (p < 0.05) in qRT-PCR. These results conclusively depicted that roflumilast could be a potential candidate as an effective therapeutic agent in the management of HD through the cAMP/CREB/BDNF signaling pathway.

Protective effect of Indole-3-carbinol, an NF-κB inhibitor in experimental paradigm of Parkinson's disease: In silico and in vivo studies.

Parkinson's disease (PD) is a progressive neurodegenerative disorder, majorly with symptoms of motor dysfunction. Study was performed to explore the effect of nuclear factor κB (NF-κB) inhibitors against neurobehavioral abnormalities and neuroinflammation in PD. Cost effective in silico approaches of docking-based ligand -target complex predictions and optimal physicochemical properties were utilised to identify lead NF-κB inhibitor using database. Our studies revealed the potential hit Indole-3-carbinol (I3C) which was considered for the next phase, pharmacological validations. Intranigral administration of lipopolysaccharide (LPS) in rats is utilized as a neuroinflmmation model of PD. In the present study it caused an impairment in motor functions, its coordination, learning and memory as demonstrated in rotarod apparatus, beam balance test, open field test and Morris water maze test. Chronic administration of I3C for 21 days in intranigral LPS treated rats led to a significant improvement in motor functions, coordination, learning and memory which were associated with a decrease in the activity of inflammatory cytokines such as TNF-α and IL-6. Further, it was found to inhibit NF-κB whose levels increased after LPS administration. Moreover, decreased levels of malondialdehyde and increased levels of reduced glutathione, superoxide dismutase and catalase were observed in cortex and striatum after I3C administration in LPS rats. These results suggest a possible neuroprotective effect of I3C via amelioration of LPS-induced behavioural alterations, oxidative damage and neuroinflammation which in turn is attributed to its potent antioxidant and anti-inflammatory (NF-κB inhibition) property. The effect produced by I3C (50 mg/kg) was found to be comparable with levodopa-carbidopa combination (LD:CD) while, I3C (50 mg/kg) in combination with LD:CD exhibited a potentiating effect in improving motor impairments and cognitive deficit. The results thus depict I3C as a promising agent to delay neurodegeneration of the neurons in PD with improvement in motor functions and cognitive function.

Sodium orthovanadate improves learning and memory in intracerebroventricular-streptozotocin rat model of Alzheimer's disease through modulation of brain insulin resistance induced tau pathology.

Sporadic Alzheimer's disease (sAD) is the most common type of dementia and progressive neurodegenerative disease. To establish the sAD model, intracerebroventricular (ICV) streptozotocin (STZ) at a dose of 3 mg/kg was administered bilaterally in rats on a stereotaxic apparatus. Behavioral tests such as Morris water maze (MWM), novel object recognition (NOR) and open field test were performed to evaluate cognitive and locomotor functions. Two treatment doses (5 mg/kg and 10 mg/kg) of sodium orthovanadate (SOV) and rivastigmine (2 mg/kg) were given orally to ICV-STZ induced rats for 21 days. Cortical and hippocampal tissues were dissected. Estimation of oxidative stress, mitochondrial dysfunction as complex I, II, III, IV activity, cholinergic function as acetylcholinesterase activity, ELISA for phosphorylated tau protein and insulin degrading enzyme (IDE), neuroinflammation as NF-κB gene expression and insulin signaling functioning as Q-RT-PCR for IR, IRS-1, PI3K, AKT, GSK-3ß gene expression were performed. Behavioral results with SOV and rivastigmine treatment revealed decreased escape latency and increased discrimination index in MWM and NOR respectively. Treatment results with SOV also demonstrated attenuation of oxidative imbalance, improved mitochondrial activity, and reversed IDE and tau pathology. SOV treatment upregulated gene expression of IR, IRS-1, PI3K, and AKT, and downregulated that of GSK-3ß. SOV results were compared with standard drug rivastigmine. Conclusively, the memory enhancement by SOV was mediated through oxidative balance, mitochondrial enzyme complex activation, and improved insulin signaling regulation. However, the primary mechanism of SOV remained attenuation of tau pathology by the upregulation of IRS-1/PI3K/AKT/GSK-3ß pathway and reversal of insulin resistance in terms of IDE. Hence, in sAD paradigm, SOV contributed to memory improvement evident with the findings of behavioral studies, which can further potentially have clinical significance in AD.

Beneficial effects of ferulic acid alone and in combination with insulin in streptozotocin induced diabetic neuropathy in Sprague Dawley rats.

BACKGROUND: Ferulic acid (FA) is a phenolic phytochemical known to protect against various diabetic complications. However, its role in diabetic neuropathy is still unclear. The present study investigated the potential protective effects of FA alone and its combination with insulin against streptozotocin (STZ)-induced diabetic neuropathy in rats. METHODS: STZ (55 mg/kg) was injected in adult Sprague-Dawley rats to induce diabetes. Diabetic rats were treated with FA (25, 50, and 100 mg/kg, p.o), insulin (10 IU/kg, s.c.) and the combination of FA (100 mg/kg, p.o.) with insulin (10 IU/kg, s.c.) for four weeks. Body weight, blood glucose, insulin, glycosylated hemoglobin, nerve conduction velocity and pain parameters were measured. Moreover, oxidative stress, inflammatory (TNF-α, IL-1ß, COX-2) and apoptotic markers (Bcl-2, Bax, caspase 3) were assessed in the sciatic nerve tissue. Na+-K+-ATPase activity and nerve growth factor (NGF) levels were also determined. RESULTS: FA attenuated STZ induced alteration in metabolic parameters, nociceptive threshold, motor nerve conduction velocity, NGF levels and Na+-K+-ATPase activity. In addition, FA boosted anti-oxidant defenses and suppressed oxidative stress, pro-inflammatory mediators and apoptotic markers. Furthermore, diabetic rats treated with insulin-FA (100 mg/kg) combination demonstrated more pronounced beneficial effects as compared to either agent alone. CONCLUSIONS: Collectively, our results suggest that FA either alone or in combination with insulin therapy could serve as an efficacious agent for treating diabetic neuropathy.

Insulin signaling pathway and related molecules: Role in neurodegeneration and Alzheimer's disease.

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases. Its major pathological hallmarks, neurofibrillary tangles (NFT), and amyloid-ß plaques can result from dysfunctional insulin signaling. Insulin is an important growth factor that regulates cell growth, energy utilization, mitochondrial function, autophagy, oxidative stress, synaptic plasticity, and cognitive function. Insulin and its downstream signaling molecules are located majorly in the regions of cortex and hippocampus. The major molecules involved in impaired insulin signaling include IRS, PI3K, Akt, and GSK-3ß. Activation or inactivation of these major molecules through increased or decreased phosphorylation plays a role in insulin signaling abnormalities or insulin resistance. Insulin resistance, therefore, is considered as a major culprit in generating the hallmarks of AD arising from neuroinflammation and oxidative stress, etc. Moreover, caspases, Nrf2, and NF-κB influence this pathway in an indirect way. Various studies also suggest a strong link between Diabetes Mellitus and AD due to the impairment of insulin signaling pathway. Moreover, studies also depict a strong correlation of other neurodegenerative diseases such as Parkinson's disease and Huntington's disease with insulin resistance. Hence this review will provide an insight into the role of insulin signaling pathway and related molecules as therapeutic targets in AD and other neurodegenerative diseases.

Chromium picolinate attenuates cognitive deficit in ICV-STZ rat paradigm of sporadic Alzheimer's-like dementia via targeting neuroinflammatory and IRS-1/PI3K/AKT/GSK-3ß pathway.

Alzheimer's disease (AD) is prevalent in old age people and is one of the most common brain diseases. Brain insulin resistance, neuroinflammation, oxidative stress, and mitochondrial and cholinergic dysfunction are key features of the disease. In our study, streptozotocin (STZ) in a dose of 3 mg/kg was injected in male Wistar rats bilaterally through the intracerebroventricular (ICV) route on stereotaxic apparatus. Chromium picolinate (CrPic) was tested at doses of 1 mg/kg, 2 mg/kg, and 4 mg/kg, while rivastigmine (2 mg/kg) was used as reference standard drug. Cognitive dysfunction induced by STZ was assessed by behavioral tests like Morris water maze and novel object recognition test. Treatment with CrPic revealed attenuation of cognitive deficit. This was confirmed by behavioral tests, biochemical estimations of antioxidant enzymes, oxidative stress, nitrosative stress, and cholinergic and mitochondrial activity. CrPic did not change AchE activity significantly. STZ-induced neuroinflammation evident by increased TNF-α, IL-6, and CRP levels was also significantly decreased by CrPic. Dysfunctional insulin signaling after ICV-STZ was demonstrated by reduced IRS-1, PI3K, AKT, BDNF gene expression, and increased GSK-3ß, NF-κB gene expression with the help of qRT-PCR. CrPic treatment produced an improvement in insulin signaling revealed by increased gene expression of IRS-1, PI3-K, AKT, BDNF, and decreased gene expression of GSK-3ß and NF-κB. It was concluded that CrPic reversed AD pathology revealed by improved memory, reduced oxidative stress, neuroinflammation, mitochondrial dysfunction, and upregulated insulin signaling.

Pharmacological rewriting of fear memories: A beacon for post-traumatic stress disorder.

Post-traumatic stress disorder (PTSD) is a psychopathological response that develops after exposure to an extreme life-threatening traumatic event. Its prevalence ranges from 0.5% to 14.5% worldwide. Due to the complex pathophysiology of PTSD, currently available treatment approaches are associated with high chances of failure, thus further research to identify better pharmacotherapeutic approaches is needed. The traumatic event associated with fear memories plays an important role in the development of PTSD and could be considered as the main culprit. PTSD patient feels frightened in a safe environment as the memories of the traumatic event are revisited. Neurocircuit involving normal processing of fear memories get disturbed in PTSD hence making a fear memory to remain to dominate even after years of trauma. Persistence of fear memories could be explained by acquisition, re-(consolidation) and extinction triad as all of these processes have been widely explored in preclinical as well as clinical studies and set a therapeutic platform for fear memory associated disorders. This review focuses on neurocircuit and pathophysiology of PTSD in context to fear memories and pharmacological targeting of fear memory for the management of PTSD.