57 research outputs found
Protective Role of Ashwagandha Leaf Extract and Its Component Withanone on Scopolamine-Induced Changes in the Brain and Brain-Derived Cells
BACKGROUND:Scopolamine is a well-known cholinergic antagonist that causes amnesia in human and animal models. Scopolamine-induced amnesia in rodent models has been widely used to understand the molecular, biochemical, behavioral changes, and to delineate therapeutic targets of memory impairment. Although this has been linked to the decrease in central cholinergic neuronal activity following the blockade of muscarinic receptors, the underlying molecular and cellular mechanism(s) particularly the effect on neuroplasticity remains elusive. In the present study, we have investigated (i) the effects of scopolamine on the molecules involved in neuronal and glial plasticity both in vivo and in vitro and (ii) their recovery by alcoholic extract of Ashwagandha leaves (i-Extract). METHODOLOGY/PRINCIPAL FINDINGS:As a drug model, scopolamine hydrobromide was administered intraperitoneally to mice and its effect on the brain function was determined by molecular analyses. The results showed that the scopolamine caused downregulation of the expression of BDNF and GFAP in dose and time dependent manner, and these effects were markedly attenuated in response to i-Extract treatment. Similar to our observations in animal model system, we found that the scopolamine induced cytotoxicity in IMR32 neuronal and C6 glioma cells. It was associated with downregulation of neuronal cell markers NF-H, MAP2, PSD-95, GAP-43 and glial cell marker GFAP and with upregulation of DNA damage--γH2AX and oxidative stress--ROS markers. Furthermore, these molecules showed recovery when cells were treated with i-Extract or its purified component, withanone. CONCLUSION:Our study suggested that besides cholinergic blockade, scopolamine-induced memory loss may be associated with oxidative stress and Ashwagandha i-Extract, and withanone may serve as potential preventive and therapeutic agents for neurodegenerative disorders and hence warrant further molecular analyses
Selective Killing of Cancer Cells by Ashwagandha Leaf Extract and Its Component Withanone Involves ROS Signaling
Ashwagandha is a popular Ayurvedic herb used in Indian traditional home medicine. It has been assigned a variety of health-promoting effects of which the mechanisms remain unknown. We previously reported the selective killing of cancer cells by leaf extract of Ashwagandha (i-Extract) and its purified component Withanone. In the present study, we investigated its mechanism by loss-of-function screening (abrogation of i-Extract induced cancer cell killing) of the cellular targets and gene pathways.Randomized ribozyme library was introduced into cancer cells prior to the treatment with i-Extract. Ribozymes were recovered from cells that survived the i-Extract treatment. Gene targets of the selected ribozymes (as predicted by database search) were analyzed by bioinformatics and pathway analyses. The targets were validated for their role in i-Extract induced selective killing of cancer cells by biochemical and molecular assays. Fifteen gene-targets were identified and were investigated for their role in specific cancer cell killing activity of i-Extract and its two major components (Withaferin A and Withanone) by undertaking the shRNA-mediated gene silencing approach. Bioinformatics on the selected gene-targets revealed the involvement of p53, apoptosis and insulin/IGF signaling pathways linked to the ROS signaling. We examined the involvement of ROS-signaling components (ROS levels, DNA damage, mitochondrial structure and membrane potential) and demonstrate that the selective killing of cancer cells is mediated by induction of oxidative stress.Ashwagandha leaf extract and Withanone cause selective killing of cancer cells by induction of ROS-signaling and hence are potential reagents that could be recruited for ROS-mediated cancer chemotherapy
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Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation
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J or H mtDNA haplogroups in retinal pigment epithelial cells: Effects on cell physiology, cargo in extracellular vesicles, and differential uptake of such vesicles by naïve recipient cells
PurposeExtracellular vesicles (EVs) are predicted to represent the internal state of cells. In polarized RPE monolayers, EVs can mediate long-distance communication, requiring endocytosis via protein-protein interactions. EV uptake from oxidatively stressed donor cells triggers loss in transepithelial resistance (TER) in recipient monolayers mediated by HDAC6. Here, we examine EVs released from RPE cells with identical nuclear genes but different mitochondrial (mt)DNA haplogroups (H, J). J-cybrids produce less ATP, and the J-haplogroup is associated with a higher risk for age-related macular degeneration.MethodsCells were grown as mature monolayers to either collect EVs from apical surfaces or to serve as naïve recipient cells. Transfer assays, transferring EVs to a recipient monolayer were performed, monitoring TER and EV-uptake. The presence of known EV surface proteins was quantified by protein chemistry.ResultsH- and J-cybrids were confirmed to exhibit different levels of TER and energy metabolism. EVs from J-cybrids reduced TER in recipient ARPE-19 cells, whereas EVs from H-cybrids were ineffective. TER reduction was mediated by HDAC6 activity, and EV uptake required interaction between integrin and its ligands and surface proteoglycans. Protein quantifications confirmed elevated levels of fibronectin and annexin A2 on J-cybrid EVs.ConclusionsWe speculate that RPE EVs have a finite set of ligands (membrane proteoglycans and integrins and/or annexin A2) that are elevated in EVs from stressed cells; and that if EVs released by the RPE could be captured from serum, that they might provide a disease biomarker of RPE-dependent diseases
Combinations of Ashwagandha leaf extracts protect brain-derived cells against oxidative stress and induce differentiation.
BACKGROUND:Ashwagandha, a traditional Indian herb, has been known for its variety of therapeutic activities. We earlier demonstrated anticancer activities in the alcoholic and water extracts of the leaves that were mediated by activation of tumor suppressor functions and oxidative stress in cancer cells. Low doses of these extracts were shown to possess neuroprotective activities in vitro and in vivo assays. METHODOLOGY/PRINCIPAL FINDINGS:We used cultured glioblastoma and neuroblastoma cells to examine the effect of extracts (alcoholic and water) as well as their bioactive components for neuroprotective activities against oxidative stress. Various biochemical and imaging assays on the marker proteins of glial and neuronal cells were performed along with their survival profiles in control, stressed and recovered conditions. We found that the extracts and one of the purified components, withanone, when used at a low dose, protected the glial and neuronal cells from oxidative as well as glutamate insult, and induced their differentiation per se. Furthermore, the combinations of extracts and active component were highly potent endorsing the therapeutic merit of the combinational approach. CONCLUSION:Ashwagandha leaf derived bioactive compounds have neuroprotective potential and may serve as supplement for brain health
Role of DNA damage in i-Extract induced cytotoxicity.
<p>DNA damage foci (<i>A</i>), induction and γH2AX phosphorylation (<i>B</i>)-assessed by staining with phospho-specific antibody (100-200 cells per slide were counted) were detected in MCF7 cells treated with i-Extract, Withaferin A and Withanone. Normal cells showed DNA damage response upon the treatment with only Withaferin A (<i>A</i> and <i>C</i>).</p
Role of ROS and mitochondrial damage in i-Extract induced cytotoxicity.
<p>MCF7 cells showed the induction of ROS when treated with i-Extract, Withaferin A or Withanone (<i>A</i> and <i>B</i>). Normal cells showed ROS induction only in the presence of Withaferin A (<i>A</i>). Loss of mitochondrial membrane potential in MCF7 cancer cells, as seen by JC-1 staining was detected with i-Extract only (<i>C</i>). Preferential induction of loss of mitochondrial trans-membrane potential in MCF7 cells detected by flow cytometry using RHO-123 increased from 0.2% of population in control to 44% of population treated with i-Extract (<i>D</i>). Mitochondrial damage was detected in Withanone-treated MCF7 cells. (<i>E</i>), Transmission electron microscopic images of control and Withanone-treated MCF7 cells. Control cells showed normal elongated mitochondrial (M) with parallel cristae (a) (enlarged boxed image, <i>b</i>), Withanone-treated cells showing swollen mitochondria with reduced number of the cristae (c) (enlarged boxed image, <i>d</i>). N, Nucleus.</p
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