Investigation of the effects of swimming exercises in rats given acrylamide

BACKGROUND

Acrylamide is a toxic substance used in industrial and laboratory processes. Acrylamide exposure has a toxic effect on many systems. Protective mechanisms should be developed against the effects caused by acrylamide.

OBJECTIVE

In our study, we investigated whether exercise has a protective effect against the changes that acrylamide will cause in pancreas.

METHODS

32 adult Sprague-Dawley male rats were used. Control group was given only saline. Exercise group was applied swimming exercise for 1hour daily for 4 weeks. Acrylamide group was given 50mg/kg acrylamide by gavage for 4 weeks. Acrylamide+exercise group was applied 50mg/kg acrylamide for 4 weeks and swimming exercise for 1hour daily. After the experiment, fasting blood glucose and oral glucose tolerance test measurements were performed. Then, blood and pancreas samples were taken.

RESULTS

Acrylamide exposure caused an increase in fasting blood glucose and oral glucose tolerance, a decrease in insulin levels and oxidative stress in acrylamide group. In exercise group, these values were similar to control group and no significant change was observed in acrylamide+exercise group. While there was an increase in the number of alpha cells in acrylamide group compared to the other groups, here was a decrease in the number of beta cells compared to control group.

CONCLUSION

We can say that acrylamide causes changes in the islets of Langerhans by affecting alpha and beta cell numbers. The protective effect of exercise on beta and alpha cell mass was not statistically significant in the acrylamide+exercise group. When the results were examined, the decrease in oxidative stress and the higher number of beta and alpha cells in the acrylamide+exercise group compared to the acrylamide group suggested that 4 weeks of swimming exercise may have an effect on acrylamide exposure.

Acrylamide-induced damage to postsynaptic plasticity is CYP2E1 dependent in an SH-SY5Y co-culture system

Acrylamide (ACR), a neurotoxic substance, is characterized by a range of industrial and population exposures. The effects of ACR on synapses have been examined, but the regulation and molecular mechanism of key proteins related to ACR and its metabolite glycidamide (GA) have not been elucidated. In this study, we constructed two co-culture systems to mimic neurons that do not express and overexpress CYP2E1. In these co-cultures, we observed the effects and relative influence of ACR and GA on cell survival as well as synaptic structural and functional plasticity. Next, we investigated the relationship between ACR-induced nerve damage and key proteins in the postsynaptic membrane. After ACR exposure, cell death and synaptic damage were significantly worse in CYP2E1-overexpressing co-culture systems, suggesting that ACR-induced neurotoxicity may be related to metabolic efficiency (including CYP2E1 activity). Moreover, with increasing doses of ACR, the key postsynaptic membrane proteins PSD-95 expression was reduced and CaMKII and NMDAR-2B phosphorylation was increased. ACR exposure also triggered a rapid dose- and time-dependent increase in intracellular Ca²⁺, whose changes can affect the expression of the above-mentioned key proteins. In summary, we clarified the relationship between ACR exposure, neuronal damage and postsynaptic plasticity and proposed an ACR-CYP2E1-GA: Ca²⁺-PSD-95-NMDAR-Ca²⁺-CaMKII effect chain. This information will further improve the development of an alternative pathway strategy for investigating the risk posed by ACR.

Time Trends of Acrylamide Exposure in Europe: Combined Analysis of Published Reports and Current HBM4EU Studies

More than 20 years ago, acrylamide was added to the list of potential carcinogens found in many common dietary products and tobacco smoke. Consequently, human biomonitoring studies investigating exposure to acrylamide in the form of adducts in blood and metabolites in urine have been performed to obtain data on the actual burden in different populations of the world and in Europe. Recognizing the related health risk, the European Commission responded with measures to curb the acrylamide content in food products. In 2017, a trans-European human biomonitoring project (HBM4EU) was started with the aim to investigate exposure to several chemicals, including acrylamide. Here we set out to provide a combined analysis of previous and current European acrylamide biomonitoring study results by harmonizing and integrating different data sources, including HBM4EU aligned studies, with the aim to resolve overall and current time trends of acrylamide exposure in Europe. Data from 10 European countries were included in the analysis, comprising more than 5500 individual samples (3214 children and teenagers, 2293 adults). We utilized linear models as well as a non-linear fit and breakpoint analysis to investigate trends in temporal acrylamide exposure as well as descriptive statistics and statistical tests to validate findings. Our results indicate an overall increase in acrylamide exposure between the years 2001 and 2017. Studies with samples collected after 2018 focusing on adults do not indicate increasing exposure but show declining values. Regional differences appear to affect absolute values, but not the overall time-trend of exposure. As benchmark levels for acrylamide content in food have been adopted in Europe in 2018, our results may imply the effects of these measures, but only indicated for adults, as corresponding data are still missing for children.

Trends of Exposure to Acrylamide as Measured by Urinary Biomarkers Levels within the HBM4EU Biomonitoring Aligned Studies (2000–2021)

Acrylamide, a substance potentially carcinogenic in humans, represents a very prevalent contaminant in food and is also contained in tobacco smoke. Occupational exposure to higher concentrations of acrylamide was shown to induce neurotoxicity in humans. To minimize related risks for public health, it is vital to obtain data on the actual level of exposure in differently affected segments of the population. To achieve this aim, acrylamide has been added to the list of substances of concern to be investigated in the HBM4EU project, a European initiative to obtain biomonitoring data for a number of pollutants highly relevant for public health. This report summarizes the results obtained for acrylamide, with a focus on time-trends and recent exposure levels, obtained by HBM4EU as well as by associated studies in a total of seven European countries. Mean biomarker levels were compared by sampling year and time-trends were analyzed using linear regression models and an adequate statistical test. An increasing trend of acrylamide biomarker concentrations was found in children for the years 2014–2017, while in adults an overall increase in exposure was found to be not significant for the time period of observation (2000–2021). For smokers, represented by two studies and sampling for, over a total three years, no clear tendency was observed. In conclusion, samples from European countries indicate that average acrylamide exposure still exceeds suggested benchmark levels and may be of specific concern in children. More research is required to confirm trends of declining values observed in most recent years.

Vitamin E and 5-amino salicylic acid ameliorates acrylamide-induced peripheral neuropathy by inhibiting caspase-3 and inducible nitric oxide synthase immunoexpression

Acrylamide is a fundamental cause of accidental toxicity in humans. This study aimed to investigate the neuroprotective effect of vitamin E (Vit. E), 5-amino salicylic acid (5-ASA), and their combination against acrylamide-induced sciatic nerve toxicity. For this purpose, 25 male Wister rats were divided into 5 groups: control, acrylamide, acrylamide + Vit. E, acrylamide + 5-ASA, and acrylamide + Vit. E + 5-ASA. Food intake and body weight were assessed after 7 days. Furthermore, the gait score was also evaluated for each rat. The sciatic nerve was dissected, fixed, and processed for routine light and electron microscopic examination. Haematoxylin and eosin, osmium tetroxide for myelin sheath, and toluidine blue for semithin section were used. In addition, immunohistochemistry for caspase-3 and inducible nitric oxide synthase (iNOS) were performed. The results showed reduced food intake and body weight in acrylamide rats. Abnormal gait score was also recorded in acrylamide rats with significant improvement in Vit. E, and Vit. E + 5-ASA groups. Histologically, Vit. E and 5-ASA provided potential protection against decreased sciatic nerve axon density, disrupted myelination, and the alteration in the immunohistochemistry induced by acrylamide. Vit. E and its combination with 5-ASA provided more evident protection compared to 5-ASA alone. 5-ASA significantly decreased apoptotic cell death (caspase-3 immunoexpression) while Vit. E failed. Both Vit. E and 5-ASA significantly decreased iNOS immunoexpression in the sciatic nerve, where 5-ASA was superior to Vit. E. These findings concluded that both Vit. E and 5-ASA protect against acrylamide-induced peripheral neuropathy through downregulation of both caspase-3 and iNOS immunoexpression.