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DNA barcoding detects contamination and substitution in North American herbal products

November 5, 2013 Comments off

DNA barcoding detects contamination and substitution in North American herbal products
Source: BMC Medicine

Background
Herbal products available to consumers in the marketplace may be contaminated or substituted with alternative plant species and fillers that are not listed on the labels. According to the World Health Organization, the adulteration of herbal products is a threat to consumer safety. Our research aimed to investigate herbal product integrity and authenticity with the goal of protecting consumers from health risks associated with product substitution and contamination.

Methods
We used DNA barcoding to conduct a blind test of the authenticity for (i) 44 herbal products representing 12 companies and 30 different species of herbs, and (ii) 50 leaf samples collected from 42 herbal species. Our laboratory also assembled the first standard reference material (SRM) herbal barcode library from 100 herbal species of known provenance that were used to identify the unknown herbal products and leaf samples.

Results
We recovered DNA barcodes from most herbal products (91%) and all leaf samples (100%), with 95% species resolution using a tiered approach (rbcL + ITS2). Most (59%) of the products tested contained DNA barcodes from plant species not listed on the labels. Although we were able to authenticate almost half (48%) of the products, one-third of these also contained contaminants and or fillers not listed on the label. Product substitution occurred in 30/44 of the products tested and only 2/12 companies had products without any substitution, contamination or fillers. Some of the contaminants we found pose serious health risks to consumers.

Conclusions
Most of the herbal products tested were of poor quality, including considerable product substitution, contamination and use of fillers. These activities dilute the effectiveness of otherwise useful remedies, lowering the perceived value of all related products because of a lack of consumer confidence in them. We suggest that the herbal industry should embrace DNA barcoding for authenticating herbal products through testing of raw materials used in manufacturing products. The use of an SRM DNA herbal barcode library for testing bulk materials could provide a method for ‘best practices? in the manufacturing of herbal products. This would provide consumers with safe, high quality herbal products.

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Ancestral dichlorodiphenyltrichloroethane (DDT) exposure promotes epigenetic transgenerational inheritance of obesity

October 23, 2013 Comments off

Ancestral dichlorodiphenyltrichloroethane (DDT) exposure promotes epigenetic transgenerational inheritance of obesity
Source: BMC Medicine

Background
Ancestral environmental exposures to a variety of environmental factors and toxicants have been shown to promote the epigenetic transgenerational inheritance of adult onset disease. The present work examined the potential transgenerational actions of the insecticide dichlorodiphenyltrichloroethane (DDT) on obesity and associated disease.

Methods
Outbred gestating female rats were transiently exposed to a vehicle control or DDT and the F1 generation offspring bred to generate the F2 generation and F2 generation bred to generate the F3 generation. The F1 and F3 generation control and DDT lineage rats were aged and various pathologies investigated. The F3 generation male sperm were collected to investigate methylation between the control and DDT lineage male sperm.

Results
The F1 generation offspring (directly exposed as a fetus) derived from the F0 generation exposed gestating female rats were not found to develop obesity. The F1 generation DDT lineage animals did develop kidney disease, prostate disease, ovary disease and tumor development as adults. Interestingly, the F3 generation (great grand-offspring) had over 50% of males and females develop obesity. Several transgenerational diseases previously shown to be associated with metabolic syndrome and obesity were observed in the testis, ovary and kidney. The transgenerational transmission of disease was through both female (egg) and male (sperm) germlines. F3 generation sperm epimutations, differential DNA methylation regions (DMR), induced by DDT were identified. A number of the genes associated with the DMR have previously been shown to be associated with obesity.

Conclusions
Observations indicate ancestral exposure to DDT can promote obesity and associated disease transgenerationally. The etiology of disease such as obesity may be in part due to environmentally induced epigenetic transgenerational inheritance.

See: Researchers Link DDT, Obesity (Science Daily)

So depression is an inflammatory disease, but where does the inflammation come from?

September 24, 2013 Comments off

So depression is an inflammatory disease, but where does the inflammation come from?
Source: BMC Medicine

Background
We now know that depression is associated with a chronic, low-grade inflammatory response and activation of cell-mediated immunity, as well as activation of the compensatory anti-inflammatory reflex system. It is similarly accompanied by increased oxidative and nitrosative stress (O&NS), which contribute to neuroprogression in the disorder. The obvious question this poses is ‘what is the source of this chronic low-grade inflammation?’

Discussion
This review explores the role of inflammation and oxidative and nitrosative stress as possible mediators of known environmental risk factors in depression, and discusses potential implications of these findings. A range of factors appear to increase the risk for the development of depression, and seem to be associated with systemic inflammation; these include psychosocial stressors, poor diet, physical inactivity, obesity, smoking, altered gut permeability, atopy, dental cares, sleep and vitamin D deficiency.

Summary
The identification of known sources of inflammation provides support for inflammation as a mediating pathway to both risk and neuroprogression in depression. Critically, most of these factors are plastic, and potentially amenable to therapeutic and preventative interventions. Most, but not all, of the above mentioned sources of inflammation may play a role in other psychiatric disorders, such as bipolar disorder, schizophrenia, autism and post-traumatic stress disorder.

Meat consumption and mortality – results from the European Prospective Investigation into Cancer and Nutrition

March 7, 2013 Comments off

Meat consumption and mortality – results from the European Prospective Investigation into Cancer and Nutrition

Source: BMC Medicine

Background

Recently, some US cohorts have shown a moderate association between red and processed meat consumption and mortality supporting the results of previous studies among vegetarians. The aim of this study was to examine the association of red meat, processed meat, and poultry consumption with risk of early death in the European Prospective Investigation into Cancer and Nutrition (EPIC).

Methods

Included in the analysis were 448,568 men and women without prevalent cancer, stroke, or myocardial infarction, and with complete information on diet, smoking, physical activity and body mass index, who were between 35 and 69 years old at baseline. Cox proportional hazards regression was used to examine the association of meat consumption with all-cause and cause-specific mortality.

Results

Until June 2009, 26,344 deaths were observed. After multivariate adjustment, a high consumption of red meat was related to higher all-cause mortality (HR=1.14, 95% CI 1.01-1.28, 160+ vs. 10-19.9 g/day), and the association was stronger for processed meat (HR=1.44, 95% CI 1.24-1.66, 160+ vs. 10-19.9 g/day). After correction for measurement error, higher all-cause mortality remained significant only for processed meat (HR=1.18, 95% CI 1.11-1.25, per 50 g/d). We estimated that 3.3% (95% CI 1.5-5.0%) of deaths could be prevented if all participants had a processed meat consumption of less than 20 g per day. Significant associations with processed meat intake were observed for cardiovascular diseases, cancer, and ‘other causes of death’. The consumption of poultry was not related to all-cause mortality.

Conclusions

The results of our analysis support a moderate positive association between processed meat consumption and mortality in particular due to cardiovascular diseases, but also cancer.

Health surveillance of deployed military personnel occasionally leads to unexpected findings

October 30, 2012 Comments off

Health surveillance of deployed military personnel occasionally leads to unexpected findings

Source: BMC Medicine

Post-traumatic stress disorder (PTSD) can be caused by life threatening illness, such as cancer and coronary events. The study by Forbes et al. made the unexpected finding that military personnel evacuation with medical illness have similar rates of PTSD to those evacuated with combat injuries. It may be that the illness acts as a nonspecific stressor that interacts with combat exposures to increase the risk of PTSD. Conversely, the inflammatory consequence of systemic illness may augment the effects to traumatic stress and facilitate the immunological abnormalities that are now being associated with PTSD and depression. The impact of the stress on cytokine systems and their role in the onset of PTSD demands further investigation. Military personnel evacuated due to physical illness require similar screening and monitoring for the risk of PTSD to those injured who are already known to be at high risk. Please see related article: http://www.biomedcentral.com/1471-244X/12/178.

Cross-national epidemiology of DSM-IV major depressive episode

September 18, 2011 Comments off

Cross-national epidemiology of DSM-IV major depressive episode
Source: BMC Medicine

Background
Major depression is one of the leading causes of disability worldwide, yet epidemiologic data are not available for many countries, particularly low-middle income countries. This paper presents data on the prevalence, impairment, and demographic correlates of depression from 18 high and low-middle income countries in the World Mental Health Survey Initiative.

Methods
DSM-IV major depressive episodes (MDE) were evaluated in face-to-face interviews using the World Health Organization Composite International Diagnostic Interview (CIDI). Data from 18 countries were analyzed in this report (n = 89,037). All countries surveyed representative, population-based samples of adults.

Results
The average lifetime and 12-month prevalence estimates of DSM-IV MDE were 14.6% and 5.5% in the 10 high income and 11.1% and 5.9% in the 8 low-middle income countries. The average age of onset ascertained retrospectively was 25.7 in high and 24.0 in low-middle income countries. Functional impairment was associated with recency of MDE. The female:male ratio was about 2:1. In high income countries, younger age was associated with higher 12-month prevalence; in several low-middle income countries, in comparison, older age was associated with greater likelihood of MDE. The strongest demographic correlate in high income countries was being separated and in low-middle income countries was being divorced or widowed.

Conclusions
MDE is a significant public health problem across all regions of the world and is strongly linked to social conditions. Future research is needed to investigate the combination of demographic risk factors that are most strongly associated with MDE in the specific countries included in the WMH.

+ Full Paper (PDF)

Divergence of gut permeability and mucosal immune gene expression in two gluten-associated conditions: celiac disease and gluten sensitivity

March 15, 2011 Comments off

Divergence of gut permeability and mucosal immune gene expression in two gluten-associated conditions: celiac disease and gluten sensitivity
Source: BMC Medicine

Background
Celiac disease (CD) is an autoimmune enteropathy triggered by the ingestion of gluten. Gluten-sensitive individuals (GS) cannot tolerate gluten and may develop gastrointestinal symptoms similar to those in CD, but the overall clinical picture is generally less severe and is not accompanied by the concurrence of tissue transglutaminase autoantibodies or autoimmune comorbidities. By studying and comparing mucosal expression of genes associated with intestinal barrier function, as well as innate and adaptive immunity in CD compared with GS, we sought to better understand the similarities and differences between these two gluten-associated disorders.

Methods
CD, GS and healthy, gluten-tolerant individuals were enrolled in this study. Intestinal permeability was evaluated using a lactulose and mannitol probe, and mucosal biopsy specimens were collected to study the expression of genes involved in barrier function and immunity.

Results
Unlike CD, GS is not associated with increased intestinal permeability. In fact, this was significantly reduced in GS compared with controls (P = 0.0308), paralleled by significantly increased expression of claudin (CLDN) 4 (P = 0.0286). Relative to controls, adaptive immunity markers interleukin (IL)-6 (P = 0.0124) and IL-21 (P = 0.0572) were expressed at higher levels in CD but not in GS, while expression of the innate immunity marker Toll-like receptor (TLR) 2 was increased in GS but not in CD (P = 0.0295). Finally, expression of the T-regulatory cell marker FOXP3 was significantly reduced in GS relative to controls (P = 0.0325) and CD patients (P = 0.0293).

Conclusions
This study shows that the two gluten-associated disorders, CD and GS, are different clinical entities, and it contributes to the characterization of GS as a condition associated with prevalent gluten-induced activation of innate, rather than adaptive, immune responses in the absence of detectable changes in mucosal barrier function.

+ Full Paper (PDF)

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