Histopathological comparison of the salivary glands’ acini and striated ducts after experimental prolonged daily administration of oral ubiquinone doses in rats

Also called coenzyme Q10 (CoQ10), Ubiquinone is a vitamin-like endogenously produced factor essential for Adenosine triphosphate (ATP) mitochondrial production. Several research studies have reported that the exogenous supplementation of CoQ10 can lead to excessive salivation, especially in patients complaining of dry mouth. The objective of this study was to investigate the effect of long-term daily use of CoQ10 on the salivary glands in experimental animals by comparing the diameters of the glandular acini and striated ducts of a CoQ10-treated group and a control group. Twenty-five white albino rats were randomly divided into two groups; the control group consisted of 10 rats, while the CoQ10-treated group comprised 15 rats. The latter received daily oral treatment of 300 mg/kg CoQ10 for six weeks. Samples of the parotid, submandibular and sublingual glands were then dissected and examined histologically for comparative measurement of the diameters of the glands’ acini and striated ducts. The CoQ10 treated group had mean diameters of the serous acini for the parotid (79.8±11.2 μm) and submandibular (81.07±13.5 μm) glands that were significantly higher (P<0.05) than their diameters in the control group (67.5±8.4 μm and 73.3±13.8 μm), respectively. However, the difference was not statistically significant when comparing the diameters of striated ducts of the CoQ10-treated group and the control group. Continuous and prolonged exposure to exogenous ubiquinone may cause hypertrophic dilation of the acini within the salivary glands, namely the parotid and submandibular glands, which might be the underlying mechanism for excessive salivation. This can be considered a reversible adaptive response.