Effect of a caffeinated energy drink and its withdrawal on the submandibular salivary gland of adult male albino rats: A histological and immunohistochemical study

Introduction: Energy drinks provide the consumer witha combination of stimulants and energy boosters that increases the physical endurance, concentration, muscular performance and mood. Despite their benefits, many health hazards occur that may be attributed to its caffeine content.
Aim: To study the effect of a caffeinated energy drink on the histological structure of submandibular salivary gland of albino rats and evaluation of the effect of its withdrawal.
Materials and Methods: Thirty adult male albino rats were divided into 3 equal groups: control group, group II (received the energy drink in a dose 3.75 ml/Kg daily orally for 8 weeks), group III (received the energy drink in a dose 3.75 ml/Kg daily orally for 8 weeks, and left for another 8 weeks without treatment). The submandibular salivary gland specimens were taken and prepared for light and electron microscopic study and immunohistochemical staining for myoepithelial cells using anti α-SMA antibody.
Results: Specimens from group II showed disturbance of the normal structure of the submandibular salivary glands. The lining epithelium of the acini and ducts showed cytoplasmic vacuoles with compressed or pyknotic nuclei. Disturbance of the basal striation of the cells lining striated ducts. There was deposition of abundant collagen fibers between the lobules and around the acini and ducts. A statistically highly significant increase in α-SMA immunoreaction was noticed around the acini, intercalated, striated and granular ducts. Ultrastructurally, fusion of the secretory granules, swollen mitochondria, dilatation and fragmentation of rough endoplasmic reticulum of the acinar cells were observed. Amelioration of the previous histological changes was detected in group III after withdrawal of the caffeinated energy drink.
Conclusion: The caffeinated energy drink induced structural changes in the submandibular salivary gland of Albino rats which were partially ameliorated by its withdrawal. So, excessive intake of the caffeinated energy drinks should be considered as health hazard for human.