Histological changes in adult rat pancreas upon chronic administration of aspartame

Background: Aspartame is the most popular artificial sweetener consumed by many individuals worldwide. Yet, there is still a debate on its consumption as an alternative to sugar. Further studies are warranted to assess the effects of aspartame on pancreas morphodynamics. Aim of the study: The present study aimed to evaluate the effects of chronic aspartame administration on the histological structure of rat pancreas. Materials and methods: Twenty male albino rats aged 3 months were divided into two equal groups: a control group (group I) and an experimental group (group II), which included rats that received 250 mg/kg/day aspartame once daily for 6 months. The pancreatic tails were processed for light and electron microscopy. The pancreatic islets were evaluated by immunohistochemical stain for the identification of insulin-secreting β cells. Results: In group II, binucleated acinar cells, prominent nucleoli, and a relative decrease in secretory granules were observed. Some islet cells showed an acidophilic granular cytoplasm and deeply stained nuclei. A strong positive immunoreaction for insulin was observed in β cells. Ultrastructurally, acinar cells showed euchromatic nuclei with multiple nucleoli. The proliferation and dilatation of rough endoplasmic reticulum had occurred with disturbed cell polarity. Secretory granules were deficient in most acinar cells. β Cells showed an apparent increase in the amount of secretory granules, especially immature ones, and a variable degree of vacuolation. Conclusion: Chronic administration of aspartame to adult rats could exert a hyperstimulatory effect on pancreatic acinar and β cells, leading to the risk of development of pancreatitis and/or diabetes.