ABSTRACT
OBJECTIVES: Dry mouth is a condition associated with reduced salivary secretion and is thought to be related to aging. This study was conducted to test whether reduced (ubiquinol) or oxidized (ubiquinone) forms of CoQ10 affect salivary secretion and salivary CoQ10 content before and after treatment. DESIGN AND METHODS: Sixty-six patients were given either ubiquinol or ubiquinone orally at a dosage of 100 mg/day, or a placebo for 1 month, and salivary secretion and salivary CoQ10 content were analyzed before and after treatment. RESULTS: Both parameters were significantly improved following treatment with either form of CoQ10, suggesting the effectiveness of CoQ10 in attenuating dry mouth symptoms. CONCLUSION: CoQ10 was locally detected in salivary glands, suggesting that orally administered CoQ10 was transported to the salivary glands via the blood stream and exerted its activity, improving salivary secretion.
Subject(s)
Salivation/drug effects , Ubiquinone/analogs & derivatives , Administration, Oral , Aged , Antioxidants/metabolism , Female , Humans , Male , Middle Aged , Ubiquinone/administration & dosage , Ubiquinone/pharmacologyABSTRACT
The involvement of reactive oxygen species (ROS) in the pathophysiology of Sjögren's syndrome (SS), an autoimmune disorder, and irradiation-induced impairments in salivary secretion has been reported. Meanwhile, the strong antioxidant astaxanthin (Ast) has been suggested to have therapeutic effects on various diseases. In the present study, we examined the ROS scavenging capacity of Ast using a human salivary gland epithelial cell line (HSY) and investigated the effects of Ast on salivary secretion in a mouse model of irradiation-induced salivary gland dysfunction. Furthermore, we performed a clinical study of Ast in six SS patients and six normal individuals, quantifying the volume of saliva secretion and the level of oxidative stress markers in the saliva. Ast partially suppressed hydrogen peroxide-induced ROS in HSY cells. The mouse model demonstrated that the pre-administration of Ast resulted in the suppression of irradiation-induced hyposalivation. Furthermore, the administration of Ast appeared to increase salivary output in both the SS and normal groups. The level of oxidative stress marker, hexanoyl-lysine, in the saliva was reduced after Ast intake. These results suggest that Ast might act as an ROS scavenger, providing benefits to SS patients with impaired salivary secretion.
ABSTRACT
Reactive oxygen species (ROS) are believed to be involved in radiation-induced xerostomia, and the application of antioxidants may be a promising method for treating patients suffering from salivary gland dysfunction. In this study, we examined the ability of the antioxidant superoxide dismutase (SOD) to restore radiation-induced salivary gland dysfunction using a mouse model of radiation-induced salivary gland hypofunction and ultraviolet B (UVB)-irradiated human salivary gland cells. We administered lecithinized SOD (PC-SOD) prior to and after irradiation and measured the amount of saliva secreted. To confirm ROS generation, flow cytometry was performed using an oxidant-sensitive fluorescent dye, dihydroethidium, and CM-H(2)DCFDA. While no significant decrease in saliva secretion was observed after irradiation in the mice that were treated with PC-SOD, a significant reduction in saliva secretion was noted in the irradiated mice that were not treated with PC-SOD. Furthermore, flow cytometry clearly revealed that PC-SOD eliminated superoxide (O(2)(-)) induced by UVB radiation. These results suggested that PC-SOD may protect against exocrine gland dysfunction induced by radiation, presumably by rapidly converting O(2)(-) to hydrogen peroxide. We believe that our results may advance the potential application of antioxidants for the prevention of ROS-induced xerostomia.
Subject(s)
Phosphatidylcholines/administration & dosage , Radiation Injuries/metabolism , Radiation Injuries/prevention & control , Radiation Tolerance/drug effects , Reactive Oxygen Species/adverse effects , Saliva/metabolism , Superoxide Dismutase/administration & dosage , Xerostomia/metabolism , Xerostomia/prevention & control , Animals , Beta Particles , Dose-Response Relationship, Drug , Dose-Response Relationship, Radiation , Mice , Mice, Inbred C57BL , Radiation Dosage , Radiation Injuries/etiology , Xerostomia/etiologyABSTRACT
OBJECTIVE: To determine the involvement of oxidative stress in the salivary gland of patients with Sjogren's syndrome (SS). METHODS: Oxidative damage to the gland was measured by 8-hydroxy-2'-deoxyguanosine (8-OHdG) and hexanoyl-lysine (HEL) using the SS saliva. In addition, lactate dehydrogenase (LDH) and mitochondrial glutamic-oxaloacetic transaminase (m-GOT), both general markers for cell damage, were also analyzed. RESULTS: Increased levels of 8-OHdG and HEL were found in the saliva of SS patients, but not in that of patients with other salivary gland dysfunction or of healthy individuals. Levels of LDH and m-GOT were significantly correlated with 8-OHdG and HEL levels, respectively. Furthermore, the increased levels of 8-OHdG and HEL were also correlated in the SS saliva. CONCLUSION: These findings suggested the involvement of oxidative stress in glandular tissue destruction in SS. It was indicated that the detection of 8-OHdG and HEL in the saliva may become a useful tool for the diagnosis of SS.
