Neurodegenerative diseases such as Alzheimer’s disease (AD), Parkinson’s disease (PD), Amyotrophic lateral sclerosis (ALS) and retinal degeneration have been studied extensively and varying molecular mechanisms have been proposed for onset of such diseases. Although genetic analysis of these diseases has also been described, yet the mechanisms governing the extent of vulnerability to such diseases remains unresolved. Recent studies have, therefore, focused on the role of environmental exposure in progression of such diseases especially in the context of prenatal and postnatal life, explaining how molecular mechanisms mediate epigenetic changes leading to degenerative diseases. This review summarizes both the animal and human studies describing various environmental stimuli to which an individual or an animal is exposed during in-utero and postnatal period and mechanisms that promote neurodegeneration. The SNPs mediating gene environment interaction are also described. Further, preventive and therapeutic strategies are suggested for effective intervention.

Preclinical studies are essential for translation to disease treatments and effective use in clinical practice. An undue emphasis on single approaches to Alzheimer’s disease (AD) appears to have retarded the pace of translation in the field, and there is much frustration in the public about the lack of an effective treatment. We critically reviewed past literature (1990–2014), analyzed numerous data, and discussed key issues at a consensus conference on Brain Ageing and Dementia to identify and overcome roadblocks in studies intended for translation. We highlight various factors that influence the translation of preclinical research and highlight specific preclinical strategies that have failed to demonstrate efficacy in clinical trials. The field has been hindered by the domination of the amyloid hypothesis in AD pathogenesis while the causative pathways in disease pathology are widely considered to be multifactorial. Understanding the causative events and mechanisms in the pathogenesis are equally important for translation. Greater efforts are necessary to fill in the gaps and overcome a variety of confounds in the generation, study design, testing, and evaluation of animal models and the application to future novel anti-dementia drug trials. A greater variety of potential disease mechanisms must be entertained to enhance progress.

The convolution associated with memory is being resolved with advancement in neuroscience. According to the concurrent assumptions, synaptic plasticity forms one of the basis of memory formation, stabilization and strengthening. In Alzheimer's disease (AD), which is generally characterized by memory dysfunction, connections amongst the cells in the brain are attenuated or lost leading to degeneration, of neural networks. Numerous attempts have been made to find new therapies for memory dysfunction with increasing attention and investments being laid on herbal drugs. Many herbal plants and extracts have already documented beneficial results when tested for antiamnesic effects. Brahmi (Bacopa monniera) is one such common herbal drug, which is employed for a long time in the Indian and chinese medical system in order to treat several disorders. Previous research has shown that Brahmi exerts many pharmacological effects including memory boosting capacity in the treatment of Alzheimer’s disease and Schizophrenia, exhibiting antiparkinsonian, antistroke, and anticonvulsant potentials. The present review discusses the chemical constituents of Brahmi along with in vitro and in vivo studies based on the pharmacological effects exerted by it. The efficacy of Brahmi in treating various disorders has evoked sufficient research in recent years and time is ripe to launch multiple clinical trials.

Scopolamine, an anticholinergic, is an attractive amnesic agent for discerning the action of candidate antiamnesic drugs. Bacopa monniera Linn (Syn. Brahmi) is one such antiamnesic agent that is frequently used in the ancient Indian medical system. We have earlier reported the reversal of diazepam‐induced amnesia with B. monniera. In this study we wanted to test if scopolamine‐induced impairment of spatial memory can also be ameliorated by B. monniera using water maze mouse model. The objective of study was to study the effect of B. monniera on scopolamine‐induced amnesia. We employed Morris water maze scale to test the amnesic effect of scopolamine and its reversal by B. monniera. Rotarod test was conducted to screen muscle coordination activity of mice. Scopolamine significantly impaired the acquisition and retrieval of memory producing both anterograde and retrograde amnesia. Bacopa monniera extract was able to reverse both anterograde and retrograde amnesia. We propose that B. monniera’s effects on cholinergic system may be helpful for developing alternative therapeutic approaches for the treatment of Alzheimer’s disease.

Alzheimer’s disease (AD) is one of the most common causes of dementia. Despite several decades of research in AD, there is no standard disease- modifying therapy available and currentlyapproved drugs provide only symptomatic relief. Stem cells hold immense potential to regenerate damaged tissues and are currently tested in some brain-related disorders, such as AD, amyotrophic lateral sclerosis (ALS) and Parkinson’s disease (PD). We review stem cell transplantation studies using preclinical and clinical tools. We describe different sources of stem cells used in various animal models and explaining the putative molecular mechanisms that can rescue neurodegenerative disorders. The clinical studies suggest safety, efficacy and translational potential of stem cell therapy. The therapeutic outcome of stem cell transplantation has been promising in many studies, but no unifying hypothesis can convincingly explain the underlying mechanism. Some studies have reported paracrine effects exerted by these stem cells via the release of neurotrophic factors, while other studies describe the immunomodulatory effects exerted by the transplanted cells. There are also reports which indicate that stem cell transplantation might result in endogenous cell proliferation or replacement of diseased cells. In animal models of AD, stem cell transplantation is also believed to increase expression of synaptic proteins.

Rationale: India has a high prevalence of noncommunicable diseases (NCDs), which can be lowered by regular physical activity. To understand this association, recent population data is required which is representative of all the states and union territories of the country. Objective: We aimed to investigate the patterns of physical activity in India, stratified by zones, body mass index (BMI), urban, rural areas, and gender. Method: We present the analysis of physical activity status from the data collected during the phase 1 of a pan-India study. This ( Niyantrita Madhumeha Bharata 2017) was a multicenter pan-India cluster sampled trial with dual objectives. A survey to identify all individuals at a high risk for diabetes, using a validated instrument called the Indian Diabetes Risk Score (IDRS), was followed by a two-armed randomized yoga-based lifestyle intervention for the primary prevention of diabetes. The physical activity was scored as per IDRS (vigorous exercise or strenuous at work = 0, moderate exercise at home/work = 10, mild exercise at home/work = 20, no exercise = 30). This was done in a selected cluster using a mobile application. A weighted prevalence was calculated based on the nonresponse rate and design weight. Results: We analyzed the data from 2,33,805 individuals; the mean age was 41.4 years (SD 13.4). Of these, 50.6% were females and 49.4% were males; 45.8% were from rural areas and 54% from urban areas. The BMI was 24.7 ± 4.6 kg/m ² . Briefly, 20% were physically inactive and 57% of the people were either inactive or mildly active. 21.2% of females were found physically inactive, whereas 19.2% of males were inactive. Individuals living in urban localities were proportionately more inactive (21.7% vs. 18.8%) or mildly active (38.9% vs. 34.8%) than the rural people. Individuals from the central (29.6%) and south zones (28.6%) of the country were also relatively inactive, in contrast to those from the northwest zone (14.2%). The known diabetics were found to be physically inactive (28.3% vs. 19.8%) when compared with those unaware of their diabetic status. Conclusion: 20% and 37% of the population in India are not active or mildly active, respectively, and thus 57% of the surveyed population do not meet the physical activity regimen recommended by the World Health Organization. This puts a large Indian population at risk of developing various NCDs, which are being increasingly reported to be vulnerable to COVID-19 infections. India needs to adopt the four strategic objectives recommended by the World Health Organization for reducing the prevalence of physical inactivity.