Withania somnifera as a potential candidate to ameliorate high fat diet-induced anxiety and neuroinflammation

Current insights into transcriptional role(s) for the nutraceutical Withania somnifera in inflammation and aging

The health-beneficial effects of nutraceuticals in various diseases have received enhanced attention in recent years. Aging is a continuous process wherein physiological activity of an individual declines over time and is characterized by various indefinite hallmarks which contribute toward aging-related comorbidities in an individual which include many neurodegenerative diseases, cardiac problems, diabetes, bone-degeneration, and cancer. Cellular senescence is a homeostatic biological process that has an important function in driving aging. Currently, a growing body of evidence substantiates the connection between epigenetic modifications and the aging process, along with aging-related diseases. These modifications are now being recognized as promising targets for emerging therapeutic interventions. Considering that almost all the biological processes are modulated by RNAs, numerous RNA-binding proteins have been found to be linked to aging and age-related complexities. Currently, studies have shed light on the ability of the nutraceutical Withania somnifera (Ashwagandha) to influence RNA expression, stability, and processing, offering insights into its mechanisms of action. By targeting RNA-related pathways, Withania somnifera may exhibit promising effects in ameliorating age-associated molecular changes, which include modifications in gene expression and signaling networks. This review summarizes the potential role of Withania somnifera as a nutraceutical in modulating RNA-level changes associated with aging, encompassing both in vitro and in vivo studies. Taken together, the putative role(s) of Withania in modulation of key RNAs will provide insights into understanding the aging process and facilitate the development of various preventive and therapeutic strategies employing nutraceuticals for healthy aging.

Anti-Neuroinflammatory Effects of Adaptogens: A Mini-Review

Introduction: Adaptogens are a group of plants that exhibit complex, nonspecific effects on the human body, increasing its ability to adapt, develop resilience, and survive in stress conditions. They are found in many traditional medicinal systems and play a key role in restoring the body's strength and stamina. Research in recent years has attempted to elucidate the mechanisms behind their pharmacological effects, but it appears that these effects are difficult to define precisely and involve multiple molecular pathways. Neuroinflammation: In recent years, chronic inflammation has been recognized as one of the common features of many central nervous system disorders (dementia and other neurodegenerative diseases, depression, anxiety, ischemic stroke, and infections). Because of the specific nature of the brain, this process is called neuroinflammation, and its suppression can result in an improvement of patients' condition and may promote their recovery. Adaptogens as anti-inflammatory agents: As has been discovered, adaptogens display anti-inflammatory effects, which suggests that their application may be broader than previously thought. They regulate gene expression of anti- and proinflammatory cytokines (prostaglandins, leukotriens) and can modulate signaling pathways (e.g., NF-κB). Aim: This mini-review aims to present the anti-neuroinflammatory potential of the most important plants classified as adaptogens: Schisandra chinensis, Eleutherococcus senticosus, Rhodiola rosea and Withania somnifera.

Dietary restriction-induced alterations on estrogen receptor alpha expression in regulating fertility in male Coturnix coturnix japonica: Relevance of Withania somnifera in modulation of inflammation and oxidative stress in testis

PROBLEM

Reproductive performance of animals gets affected by nutritional restrictions which act as potential stressors leading to hormonal imbalance and testicular inflammation, the major causes of infertility. Withania somnifera (WS), well-known traditional medicinal plant, has been used as antistress and infertility treatment. Therefore, the present study looks into the ameliorative effects of WS on the reproductive and immune system of male Coturnix coturnix japonica in stressed conditions like water and food restriction focussing on the modulation in estrogen receptor alpha (ERα).

METHOD OF STUDY

Biochemical estimations for oxidative stress, histological alterations, immuno-fluorescent localization of ERα, interleukin (IL)-1β, IL-4, and interferon gamma (IFN-γ) in testicular cells were performed.

RESULTS

Nutritional restriction declines endogenous estradiol, ERα in testicular cells while it elevates corticosterone leading to oxidative stress in testis thereby reducing fertility by decrease in sperm. Results indicate significant reversal in all the parameters after the administration of WS by improving testicular cell morphology, increased superoxide and catalase activity thus reducing oxidative stress. WS increases spermatogenesis and enhances expression of ERα in testicular cells in quail. Further, WS increases IL-4, decreases IL-1β and IFN-γ expression in testis, thereby improving immune profile contrary to stressed conditions.

CONCLUSION

WS stimulates HPG-axis even after stress resulting in increased endogenous estradiol which stimulates the expression of ERα in testis; increases sperm count and immunity thereby improving the reproductive performance. WS may be the best therapy against nutritional-restriction stress induced reproductive toxicity by reducing oxidative stress mediated inflammatory response via increased testicular expression of ERα in quail.

Withania Somnifera Extract Mitigates Experimental Acute Graft versus Host Disease Without Abrogating Graft Versus Leukemia Effect

Acute graft versus host disease (aGvHD) is the major contributor of nonrelapse mortality in alloHSCT. It is associated with an inflammatory immune response manifesting as cytokine storm with ensuing damage to target organs such as liver, gut, and skin. Prevention of aGvHD while retaining the beneficial graft versus leukemia (GvL) effect remains a major challenge. Withania somnifera extract (WSE) is known for its anti-inflammatory, immune-modulatory, and anticancer properties, which are appealing in the context of aGvHD. Herein, we demonstrated that prophylactic and therapeutic use of WSE in experimental model of alloHSCT mitigates aGvHD-associated morbidity and mortality. In the prophylaxis study, a dose of 75 mg/kg of WSE offered greatest protection against death due to aGvHD (hazard ratio [HR] = 0.15 [0.03-0.68], P ≤ .01), whereas 250 mg/kg was most effective for the treatment of aGvHD (HR = 0.16 [0.05-0.5], P ≤ .01). WSE treatment protected liver, gut, and skin from damage by inhibiting cytokine storm and lymphocytic infiltration to aGvHD target organs. In addition, WSE did not compromise the GvL effect, as alloHSCT with or without WSE did not allow the leukemic A20 cells to grow. In fact, WSE showed marginal antileukemic effect in vivo. WSE is currently under clinical investigation for the prevention and treatment of aGvHD.

Lycium barbarum (Wolfberry) glycopeptide prevents stress-induced anxiety disorders by regulating oxidative stress and ferroptosis in the medial prefrontal cortex

BACKGROUND

Lycium barbarum (Wolfberry) extract has been shown to be effective in neuroprotection against aging or neural injury. Knowledge of its potential roles and biological mechanisms in relieving mental disorders, however, remains limited.

PURPOSE

To investigate the potency of Lycium barbarum glycopeptide (LbGp) in alleviating anxiety disorders and the related biological mechanisms.

METHODS

LbGp was administrated to mice subjected to 14 days of chronic restrain stress (CRS) via the intragastric route. The anxiolytic effect was evaluated by a battery of behavioral assays. The morphology of neurons and glial cells was evaluated, and cortical neuronal calcium transients were recorded in vivo. The molecular mechanism of LbGp was also investigated.

RESULTS

LbGp effectively relieved anxiety-like and depressive behaviors under CRS. Mechanistic studies further showed that LbGp treatment relieved oxidative stress and lipid peroxidation in the medial prefrontal cortex (mPFC). In particular, the ferroptosis pathway was inhibited by LbGp, revealing a previously unrecognized mechanism of the anxiolytic role of wolfberry extract.

CONCLUSION

In summary, our results supported the future development of LbGp to prevent or ameliorate stress-induced anxiety disorders. Our work provides a promising strategy for early intervention for pateitents with mental disorders by applying natural plant extracts.

Divya-WeightGo combined with moderate aerobic exercise remediates adiposopathy, insulin resistance, serum biomarkers, and hepatic lipid accumulation in high-fat diet-induced obese mice

Obesity has become an unprecedented epidemic worldwide owing to a prolonged imbalance between energy intake and expenditure. Available therapies primarily suppress energy intake but often fail to produce sustained fat loss, necessitating a more efficacious strategy to combat obesity. In this study, a polyherbal formulation, Divya-WeightGo (DWG) has been investigated for its anti-obesity activity using in-vitro and in-vivo assays. Ultra-high performance liquid chromatography (UHPLC) analysis revealed the presence of phytocompounds including gallic acid, methyl gallate, corilagin, ellagic acid, pentagalloyl glucose, withaferin A and hydroxycitric acid, proven to aid in weight loss. The exposure of 3T3-L1 cells to DWG at cytosafe concentrations inhibited lipid and triglyceride accumulation and downregulated the expression of several adipogenic and lipogenic markers like PPARy, C/EBPα, C/EBPβ, SREBP-1c, FASN and DGAT1. DWG reduced LPS-induced pro-inflammatory cytokine release and NF-κB activity in THP-1 cells. The in-vivo anti-obesity activity of DWG, both alone and in combination with moderate aerobic exercise, was assessed in a high fat diet-induced obese mouse model. DWG mitigated the obesity associated increased body weight gain, feed efficiency ratio, glucose intolerance, diminished insulin sensitivity, dyslipidemia, altered liver function profile, lipid accumulation and adiposopathy in obese mice, alone as well as in combination intervention, with better efficacy in the combination approach. Thus, the findings of this study suggest that DWG could be a promising therapeutic avenue to treat obesity through attenuation of lipid and fat accumulation in liver and adipose tissues and could be utilized as an adjunct with lifestyle interventions to combat obesity and associated complications.

Phytotherapeutic alternatives for neurodegenerative dementias: Scientific review, discussion and therapeutic proposal

The incidence and prevalence of age-related neurodegenerative dementias have been increasing. There is no curative therapy and conventional drug treatment can cause problems for patients. Medicinal plants traditionally used for problems associated with ageing are emerging as a therapeutic resource. The main aim is to give a proposal for use and future research based on scientific knowledge and tradition. A literature search was conducted in several searchable databases. The keywords used were related to neurodegenerative dementias, ageing and medicinal plants. Boolean operators and filters were used to focus the search. As a result, there is current clinical and preclinical scientific information on 49 species used in traditional medicine for ageing-related problems, including neurodegenerative dementias. There are preclinical and clinical scientific evidences on their properties against protein aggregates in the central nervous system and their effects on neuroinflammation, apoptosis dysregulation, mitochondrial dysfunction, gabaergic, glutamatergic and dopaminergic systems alterations, monoamine oxidase alterations, serotonin depletion and oestrogenic protection. In conclusion, the potential therapeutic effect of the different medicinal plants depends on the type of neurodegenerative dementia and its stage of development, but more clinical and preclinical research is needed to find better, safer and more effective treatments.

Sex Differences in Hypothalamic Changes and the Metabolic Response of TgAPP Mice to a High Fat Diet

The propensity to develop neurodegenerative diseases is influenced by diverse factors including genetic background, sex, lifestyle, including dietary habits and being overweight, and age. Indeed, with aging, there is an increased incidence of obesity and neurodegenerative processes, both of which are associated with inflammatory responses, in a sex-specific manner. High fat diet (HFD) commonly leads to obesity and markedly affects metabolism, both peripherally and centrally. Here we analyzed the metabolic and inflammatory responses of middle-aged (11–12 months old) transgenic amyloid precursor protein (TgAPP) mice of both sexes to HFD for 18 weeks (starting at 7–8 months of age). We found clear sex differences with females gaining significantly more weight and fat mass than males, with a larger increase in circulating leptin levels and expression of inflammatory markers in visceral adipose tissue. Glycemia and insulin levels increased in HFD fed mice of both sexes, with TgAPP mice being more affected than wild type (WT) mice. In the hypothalamus, murine amyloid β (Aβ) levels were increased by HFD intake exclusively in males, reaching statistical significance in TgAPP males. On a low fat diet (LFD), TgAPP males had significantly lower mRNA levels of the anorexigenic neuropeptide proopiomelanocortin (POMC) than WT males, with HFD intake decreasing the expression of the orexigenic neuropeptides Agouti-related peptide (AgRP) and neuropeptide Y (NPY), especially in TgAPP mice. In females, HFD increased POMC mRNA levels but had no effect on AgRP or NPY mRNA levels, and with no effect on genotype. There was no effect of diet or genotype on the hypothalamic inflammatory markers analyzed or the astrogliosis marker glial acidic protein (GFAP); however, levels of the microglial marker Iba-1 increased selectively in male TgAPP mice. In summary, the response to HFD intake was significantly affected by sex, with fewer effects due to genotype. Hypothalamic inflammatory cytokine expression and astrogliosis were little affected by HFD in middle-aged mice, although in TgAPP males, which showed increased Aβ, there was microglial activation. Thus, excess intake of diets high in fat should be avoided because of its possible detrimental consequences.

Aging-related changes in metabolic indicators in female rats and their management with Tinospora cordifolia

Conflicting reports of HRT necessitates exploration of therapeutic interventions with the least side effects to preserve metabolic homeodynamics in women later in life. The current study was designed to elucidate the cumulative effects of aging and/or high fat diet (HFD) on some metabolic indicators and their management by Tinospora cordifolia stem powder (TCP) using middle-aged acyclic and young adult cyclic female rats as the model system. Animals were fed on either normal chow or HFD supplemented with or without TCP. Blood and liver tissue were collected for biochemical, and histological studies as well as for expression of proteins regulating lipid metabolism. Animals fed with TCP supplemented normal chow feed showed bodyweight management over 12-weeks despite their high feed and calories intake compared to young and age-matched controls as well as HFD-fed animals. TCP dose used was not toxic and rather prevented age-associated liver dysfunctions and ameliorated dyslipidemia and oxidative stress, normalized blood glucose, insulin, leptin, and secretary pro-inflammatory cytokines. Further, bodyweight management effect of TCP was observed to target AMPK signalling pathway as the mediator of lipogenesis, sterol biosynthesis, lipolysis, and β-oxidation of fatty acids. These findings suggest that TCP supplementation in diet may be a potential interventional strategy to ameliorate aging-associated hepatic and metabolic dysfunctions and to promote healthy aging.

The Obese Brain: Mechanisms of Systemic and Local Inflammation, and Interventions to Reverse the Cognitive Deficit

Overweight and obesity are now considered a worldwide pandemic and a growing public health problem with severe economic and social consequences. Adipose tissue is an organ with neuroimmune-endocrine functions, which participates in homeostasis. So, adipocyte hypertrophy and hyperplasia induce a state of chronic inflammation that causes changes in the brain and induce neuroinflammation. Studies with obese animal models and obese patients have shown a relationship between diet and cognitive decline, especially working memory and learning deficiencies. Here we analyze how obesity-related peripheral inflammation can affect central nervous system physiology, generating neuroinflammation. Given that the blood-brain barrier is an interface between the periphery and the central nervous system, its altered physiology in obesity may mediate the consequences on various cognitive processes. Finally, several interventions, and the use of natural compounds and exercise to prevent the adverse effects of obesity in the brain are also discussed.

High-fat diet alters stress behavior, inflammatory parameters and gut microbiota in Tg APP mice in a sex-specific manner

Long-term high-fat diet (HFD) consumption commonly leads to obesity, a major health concern of western societies and a risk factor for Alzheimer's disease (AD). Both conditions present glial activation and inflammation and show sex differences in their incidence, clinical manifestation, and disease course. HFD intake has an important impact on gut microbiota, the bacteria present in the gut, and microbiota dysbiosis is associated with inflammation and certain mental disorders such as anxiety. In this study, we have analyzed the effects of a prolonged (18 weeks, starting at 7 months of age) HFD on male and female mice, both wild type (WT) and TgAPP mice, a model for AD, investigating the behavioral profile, gut microbiota composition and inflammatory/phagocytosis-related gene expression in hippocampus. In the open-field test, no overt differences in motor activity were observed between male and female or WT and TgAPP mice on a low-fat diet (LFD). However, HFD induced anxiety, as judged by decreased motor activity and increased time in the margins in the open-field, and a trend towards increased immobility time in the tail suspension test, with increased defecation. Intriguingly, female TgAPP mice on HFD showed less immobility and defecation compared to female WT mice on HFD. HFD induced dysbiosis of gut microbiota, resulting in reduced microbiota diversity and abundance compared with LFD fed mice, with some significant differences due to sex and little effect of genotype. Gene expression of pro-inflammatory/phagocytic markers in the hippocampus were not different between male and female WT mice, and in TgAPP mice of both sexes, some cytokines (IL-6 and IFNγ) were higher than in WT mice on LFD, more so in female TgAPP (IL-6). HFD induced few alterations in mRNA expression of inflammatory/phagocytosis-related genes in male mice, whether WT (IL-1β, MHCII), or TgAPP (IL-6). However, in female TgAPP, altered gene expression returned towards control levels following prolonged HFD (IL-6, IL-12β, TNFα, CD36, IRAK4, PYRY6). In summary, we demonstrate that HFD induces anxiogenic symptoms, marked alterations in gut microbiota, and increased expression of inflammatory genes, except for female TgAPP that appear to be resistant to the diet effects. Lifestyle interventions should be introduced to prevent AD onset or exacerbation by reducing inflammation and its associated symptoms; however, our results suggest that the eventual goal of developing prevention and treatment strategies should take sex into consideration.

Effects of Withania somnifera (Ashwagandha) on Stress and the Stress- Related Neuropsychiatric Disorders Anxiety, Depression, and Insomnia

BACKGROUND

Withania somnifera (WS), also known as Ashwagandha, is commonly used in Ayurveda and other traditional medicine systems. WS has seen an increase in worldwide usage due to its reputation as an adaptogen. This popularity has elicited increased scientific study of its biological effects, including a potential application for neuropsychiatric and neurodegenerative disorders.

OBJECTIVE

This review aims to provide a comprehensive summary of preclinical and clinical studies examining the neuropsychiatric effects of WS, specifically its application in stress, anxiety, depression, and insomnia.

METHODS

Reports of human trials and animal studies of WS were collected primarily from the PubMed, Scopus, and Google Scholar databases.

RESULTS

WS root and leaf extracts exhibited noteworthy anti-stress and anti-anxiety activity in animal and human studies. WS also improved symptoms of depression and insomnia, though fewer studies investigated these applications. WS may alleviate these conditions predominantly through modulation of the hypothalamic-pituitary-adrenal and sympathetic-adrenal-medullary axes, as well as through GABAergic and serotonergic pathways. While some studies link specific withanolide components to its neuropsychiatric benefits, there is evidence for the presence of additional, as yet unidentified, active compounds in WS.

CONCLUSION

While benefits were seen in the reviewed studies, significant variability in the WS extracts examined prevents a consensus on the optimum WS preparation or dosage for treating neuropsychiatric conditions. WS generally appears safe for human use; however, it will be important to investigate potential herb-drug interactions involving WS if used alongside pharmaceutical interventions. Further elucidation of active compounds of WS is also needed.

Chamomile decoction mitigates high fat diet-induced anxiety-like behavior, neuroinflammation and cerebral ROS overload

An abundant literature suggests that obesity-associated with taking a high fat diet is related to an elevated risk of type 2 diabetes and metabolic syndrome. However, metabolic disorders may be involved in the induction of the anxiogenic-like symptoms. The current study was designed to elucidate the mechanisms by which a high fat diet (HFD) can cause several complications in the WISTAR rats (Rattus norvegicus) brain. Oxidative stress and inflammation as well as the putative protection afforded by chamomile decoction extract (CDE) were also studied.The results demonstrated that the increased body and brain weight, acetylcholinesterase and butyrylcholinesterase activities as well as hypercholezterolaemia in response to HFD taking were correlated with anxiogenic-like symptoms. Moreover, HFD feed caused a brain oxidative stress characterized by increased lipoperoxidation, inhibition of antioxidant enzyme activities such as SOD, CAT and GPx, depletion of a non-enzymatic antioxidant such as sulfhydryl groups and GSH. Importantly, the results also show that HFD also provoked a cerebral overload in reactive oxygen species such as OH^•, H₂O₂ and O2∙- as well as brain inflammation assessed by the overproduction of cytokines such as IL-1β and IL-6.Interestingly, all neurobehavioral changes and all the biochemical and molecular disturbances were abolished in HFD-fed rats treated with CDE.Our results provide clear evidence that obesity and depression as well as anxiety are finely correlated and that M. recutita's decoction may prove to be a potential therapeutic agent to mitigate the behavioral disorders, the biochemical alterations and the neuroinflammation associated to the obesity.

Tinospora cordifolia ameliorates brain functions impairments associated with high fat diet induced obesity

Obesity is a rapidly growing health problem worldwide and its prevalence has increased markedly in both the developing and developed nations. It is associated with a range of co-morbidities such as cardiovascular disease, type 2 diabetes mellitus, and cognitive dysfunctions. Therefore, the need for a safe and effective treatment has led to the exploration of natural products for the management of obesity. In the present study, we tested the anxiolytic, anti-apoptotic, and anti-neuroinflammatory potential of Tinospora cordifolia in a high fat diet-induced obesity rat model system. Young female Wistar albino rats were divided into three groups: (1) Low fat diet (LFD), fed on normal chow feed; (2) High fat diet (HFD), fed on diet containing 30% fat by weight; and (3) High fat diet containing extract (HFDE), fed on high fat diet supplemented with the stem powder of T. cordifolia (TCP). The rats from each group were kept on their respective feeding regimen for 12 weeks. The body weight and calorie intake were recorded weekly. The elevated plus maze test and rotarod performance test were performed to evaluate the anxiety-like behavior and locomotor coordination, respectively. The levels of serum cytokines (IL-6 and TNF-α) were estimated and various markers for inflammation, synaptic plasticity, apoptosis, and energy homeostasis were studied by western blotting. The HFDE rats showed reduced anxiety-like behavior and improved locomotor behavior as compared to HFD-induced obese rats. The TCP supplementation in high fat diet suppressed the expression of inflammatory molecules, including serum cytokines (IL-6 and TNF-α), and modulated apoptosis and synaptic plasticity. TCP was found to be effective in managing body weight in HFD-fed rats by maintaining energy metabolism and cellular homeostasis. T. cordifolia may be recommended as a potential therapeutic agent to prevent the adverse effects of obesity and obesity-associated brain dysfunctions.

Sex-Specific Anxiety and Prefrontal Cortex Glutamatergic Dysregulation Are Long-Term Consequences of Pre-and Postnatal Exposure to Hypercaloric Diet in a Rat Model

Both maternal and early life malnutrition can cause long-term behavioral changes in the offspring, which depends on the caloric availability and the timing of the exposure. Here we investigated in a rat model whether a high-caloric palatable diet given to the mother and/or to the offspring during the perinatal and/or postnatal period might dysregulate emotional behavior and prefrontal cortex function in the offspring at adult age. To this end, we examined both anxiety responses and the mRNA/protein expression of glutamatergic, GABAergic and endocannabinoid signaling pathways in the prefrontal cortex of adult offspring. Male animals born from mothers fed the palatable diet, and who continued with this diet after weaning, exhibited anxiety associated with an overexpression of the mRNA of Grin1, Gria1 and Grm5 glutamate receptors in the prefrontal cortex. In addition, these animals had a reduced expression of the endocannabinoid system, the main inhibitory retrograde input to glutamate synapses, reflected in a decrease of the Cnr1 receptor and the Nape-pld enzyme. In conclusion, a hypercaloric maternal diet induces sex-dependent anxiety, associated with alterations in both glutamatergic and cannabinoid signaling in the prefrontal cortex, which are accentuated with the continuation of the palatable diet during the life of the offspring.

Feed restriction since lactation has reduced anxiety in adult Wistar rats

ABSTRACT Objective To evaluate the effects of macronutrients (protein, carbohydrate and/or lipid) in the diet of young adult (72 days) and adult (182 days) Wistar rats treated ad libitum and with 30% restriction from birth on anxiety in the elevated plus-maze. Methods We used 238 rats treated from birth, composing the groups: Control, Protein, Carbohydrate, Lipid, Carbohydrate and Lipid, Control Restriction, Protein Restriction, Carbohydrate Restriction, Lipid Restriction and Carbohydrate and Lipid Restriction. The animals were weighed at the beginning and at the end of the experiment and tested in the elevated plus-maze. Data were submitted to analysis of variance, followed by the Newman-Keuls Test (p<0.05). Results Among the animals treated ad libitum, the Control, Carbohydrate plus Lipid and Lipid gained more weight than the Carbohydrate and Protein; ad libitum animals gained more weight than those on restriction; among the restrictions, Carbohydrate Restriction rats were the ones that gained less weight. Diet-restricted animals exhibited reduced first-entry latency, greater percentage of entries and time spent, frequency of open arm extremity visits, head dipping (protected and unprotected), and length of stay in the central area of the elevated plus-maze. The animals with 182 days presented greater latency for first entry, reduced frequency of false entries and visits to the ends of the open arms and protected head dipping. Conclusion Food restricted animals, regardless of the macronutrient present in the diet, were less anxious and/or increased their impulsivity and those at 182 days were more anxious and/or with reduced impulsivity.

Withania somnifera (L.) Dunal ameliorates neurodegeneration and cognitive impairments associated with systemic inflammation

BACKGROUND

Systemic inflammation driven neuroinflammation is an event which correlates with pathogenesis of several neurodegenerative diseases. Therefore, targeting peripheral and central inflammation simultaneously could be a promising approach for the management of these diseases. Nowadays, herbal medicines are emerging as potent therapeutics against various brain pathologies. Therefore, in this contemporary study, the neuroprotective activity of Ashwagandha (Withania somnifera) was elucidated against the inflammation associated neurodegeneration and cognitive impairments induced by systemic LPS administration using in vivo rat model system.

METHODS

To achieve this aim, young adult wistar strain male albino rats were randomized into four groups: (i) Control, (ii) LPS alone, (iii) LPS + ASH-WEX, (iv) ASH-WEX alone. Post regimen, the animals were subjected to Rotarod, Narrow Beam Walking and Novel Object Recognition test to analyze their neuromuscular coordination, working memory and learning functions. The rats were then sacrificed to isolate the brain regions and expression of proteins associated with synaptic plasticity and cell survival was studied using Western blotting and Quantitative real time PCR. Further, neuroprotective potential of ASH-WEX and its active fraction (FIV) against inflammatory neurodegeneration was studied and validated using in vitro model system of microglial conditioned medium-treated neuronal cultures and microglial-neuronal co-cultures.

RESULTS

Orally administered ASH-WEX significantly suppressed the cognitive and motor-coordination impairments in rats. On the molecular basis, ASH-WEX supplementation also regulated the expression of various proteins involved in synaptic plasticity and neuronal cell survival. Since microglial-neuronal crosstalk is crucial for maintaining CNS homeostasis, the current study was further extended to ascertain whether LPS-mediated microglial activation caused damage to neurons via direct cell to cell contact or through secretion of inflammatory mediators. ASH-WEX and FIV pretreatment was found to restore neurite outgrowth and protect neurons from apoptotic cell death caused by LPS-induced neuroinflammation in both activated microglial conditioned medium-treated neuronal cultures as well as microglial-neuronal co-cultures.

CONCLUSION

This extensive study using in vivo and in vitro model systems provides first ever pre-clinical evidence that ASH-WEX can be used as a promising natural therapeutic remedial for the prevention of neurodegeneration and cognitive impairments associated with peripheral inflammation and neuroinflammation.

Ferulic Acid Esters and Withanolides: In Search of Withania somnifera GABAA Receptor Modulators

Nine compounds, including two undescribed withanolides, withasomniferolides A and B (1 and 2), three known withanolides (3-5), a ferulic acid dimeric ester (6), and an inseparable mixture of three long alkyl chain ferulic acid esters (7-9), were isolated from a GABA_A receptor positive activator methanol extract of the roots of Withania somnifera. The structures of the isolated compounds were elucidated based on NMR, MS, and ECD data analysis. In order to bioassay the single ferulic acid derivatives, compounds 6-9 were also synthesized. The most active compound, docosanyl ferulate (9), was able to enhance the GABA_A receptor inhibitory postsynaptic currents with an IC₅₀ value of 7.9 μM. These results, by showing an ability to modulate the GABA_A receptor function, cast fresh light on the biological activities of the secondary metabolites of W. somnifera roots.

Review of the Effect of Natural Compounds and Extracts on Neurodegeneration in Animal Models of Diabetes Mellitus

Diabetes mellitus is a chronic metabolic disease with a high prevalence in the Western population. It is characterized by pancreas failure to produce insulin, which involves high blood glucose levels. The two main forms of diabetes are type 1 and type 2 diabetes, which correspond with >85% of the cases. Diabetes shows several associated alterations including vascular dysfunction, neuropathies as well as central complications. Brain alterations in diabetes are widely studied; however, the mechanisms implicated have not been completely elucidated. Diabetic brain shows a wide profile of micro and macrostructural changes, such as neurovascular deterioration or neuroinflammation leading to neurodegeneration and progressive cognition dysfunction. Natural compounds (single isolated compounds and/or natural extracts) have been widely assessed in metabolic disorders and many of them have also shown antioxidant, antiinflamatory and neuroprotective properties at central level. This work reviews natural compounds with brain neuroprotective activities, taking into account several therapeutic targets: Inflammation and oxidative stress, vascular damage, neuronal loss or cognitive impairment. Altogether, a wide range of natural extracts and compounds contribute to limit neurodegeneration and cognitive dysfunction under diabetic state. Therefore, they could broaden therapeutic alternatives to reduce or slow down complications associated with diabetes at central level.

Exposure to an obesogenic diet during adolescence leads to abnormal maturation of neural and behavioral substrates underpinning fear and anxiety

BACKGROUND

Post-traumatic stress disorder (PTSD) and obesity are highly prevalent in adolescents. Emerging findings from our laboratory and others are consistent with the novel hypothesis that obese individuals may be predisposed to developing PTSD. Given that aberrant fear responses are pivotal in the pathogenesis of PTSD, the objective of this study was to determine the impact of an obesogenic Western-like high-fat diet (WD) on neural substrates associated with fear.

METHODS

Adolescent Lewis rats (n = 72) were fed with either the experimental WD (41.4% kcal from fat) or the control diet. The fear-potentiated startle paradigm was used to determine sustained and phasic fear responses. Diffusion tensor imaging metrics and T2 relaxation times were used to determine the structural integrity of the fear circuitry including the medial prefrontal cortex (mPFC) and the basolateral complex of the amygdala (BLA).

RESULTS

The rats that consumed the WD exhibited attenuated fear learning and fear extinction. These behavioral impairments were associated with oversaturation of the fear circuitry and astrogliosis. The BLA T2 relaxation times were significantly decreased in the WD rats relative to the controls. We found elevated fractional anisotropy in the mPFC of the rats that consumed the WD. We show that consumption of a WD may lead to long-lasting damage to components of the fear circuitry.

CONCLUSIONS

Our findings demonstrate that consumption of an obesogenic diet during adolescence has a profound impact in the maturation of the fear neurocircuitry. The implications of this research are significant as they identify potential biomarkers of risk for psychopathology in the growing obese population.