Safety Assessment of Ubiquinol Acetate: Subchronic Toxicity and Genotoxicity Studies

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.

Genotoxic risk in humans and acute toxicity in rats of a novel oral high-dose coenzyme Q10 oleogel

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An oral high-dose CoQ₁₀ oleogel was assessed in its genotoxicity and acute toxicity.

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There was no genotoxic risk associated with the use of CoQ₁₀ oleogel in volunteers.

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Biochemical parameters remained within reference values after oleogel treatment.

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No signs of toxicity or mortality were observed in the rats exposed to the oleogel.

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The novel high-dose CoQ₁₀ oleogel formulation designed is safe for oral consumption.

Coenzyme Q₁₀ (CoQ₁₀) supplementation has demonstrated to be safe and effective in primary and secondary CoQ₁₀ deficiencies. Previously, we have designed a high-dose CoQ₁₀ oleogel (1 g/disk) with excipients used in quantities that do not represent any toxic risk. However, it was necessary to demonstrate their safety in the final formulation. Following this purpose, an acute toxicity study of the oleogel in rats was performed. Furthermore, the genotoxic risk was evaluated in human volunteers after CoQ₁₀ supplementation with oleogel and compared to the solid form (1 g/three 00-size-capsules). In addition, the general health status and possible biochemical changes of the participants were determined using serum parameters. Results suggested the absence of adverse effects caused by the interaction of the components in the oleogel formulation. Therefore, we conclude that the designed novel high-dose CoQ₁₀ oleogel was safe for oral consumption.

Stability of Reduced and Oxidized Coenzyme Q10 in Finished Products

The efficiency of coenzyme Q10 (CoQ10) supplements is closely associated with its content and stability in finished products. This study aimed to provide evidence-based information on the quality and stability of CoQ10 in dietary supplements and medicines. Therefore, ubiquinol, ubiquinone, and total CoQ10 contents were determined by a validated HPLC-UV method in 11 commercial products with defined or undefined CoQ10 form. Both forms were detected in almost all tested products, resulting in a total of CoQ10 content between 82% and 166% of the declared. Ubiquinol, ubiquinone, and total CoQ10 stability in these products were evaluated within three months of accelerated stability testing. Ubiquinol, which is recognized as the less stable form, was properly stabilized. Contrarily, ubiquinone degradation and/or reduction were observed during storage in almost all tested products. These reactions were also detected at ambient temperature within the products’ shelf-lives and confirmed in ubiquinone standard solutions. Ubiquinol, generated by ubiquinone reduction with vitamin C during soft-shell capsules’ storage, may lead to higher bioavailability and health outcomes. However, such conversion and inappropriate content in products, which specify ubiquinone, are unacceptable in terms of regulation. Therefore, proper CoQ10 stabilization through final formulations regardless of the used CoQ10 form is needed.