ABSTRACT
A randomized, double-blind, placebo-controlled, parallel-group comparative clinical study was conducted to examine the effects of ubiquinol (the reduced form of Coenzyme Q10) on secretion of saliva. This interventional study enrolled 40 subjects aged 65 years or younger who were healthy, but noted slight dryness of the mouth. Subjects were randomized with stratification according to gender and age to ingestion of gummy candy containing 50 mg of ubiquinol or placebo twice daily for 8 weeks. At the end of study, along with a significant increase of the CoQ10 level in saliva (p = 0.025*, d = 0.65), there was a significant increase of the saliva flow rate (p = 0.048*, d = 0.66) in the ubiquinol candy group (n = 18; 47.4±6.2 years; 6 men and 12 women) compared to the placebo group (n = 20; 52.2±7.7 years; 4 men and 16 women). The strength of the stomatognathic muscles was not significantly enhanced by ingestion of ubiquinol candy. Compared with baseline, significant improvement of the following four questionnaire items was observed in the ubiquinol group at the end of the study: feeling tired (p = 0.00506, d = -0.726), dryness of the mouth (p = 0.04799, d = -0.648), prone to catching a cold (p = 0.00577, d = -0.963), and diarrhea (p = 0.0166, d = -0.855). There were no serious adverse events. An in vitro study revealed that ubiquinol stimulated a significant and concentration-dependent increase of ATP production by a cell line derived from human salivary gland epithelial cells (p<0.05), while 1 nM ubiquinol significantly suppressed (p = 0.028) generation of malondialdehyde by cells exposed to FeSO4-induced oxidative stress. These findings suggest that ubiquinol increases secretion of saliva by suppressing oxidative stress in the salivary glands and by promoting ATP production. Trial Registration: UMIN-CTR UMIN000024406.
Subject(s)
Adenosine Triphosphate/metabolism , Candy , Saliva/metabolism , Ubiquinone/analogs & derivatives , Adult , Antioxidants/metabolism , Cell Line , Deglutition , Double-Blind Method , Female , Humans , Japan , Male , Malondialdehyde/metabolism , Middle Aged , Oxidative Stress , Salivary Glands/physiology , Surveys and Questionnaires , Ubiquinone/metabolism , Ubiquinone/pharmacologyABSTRACT
The cDNA clones for five novel isoforms of prostaglandin (PG) F2 alpha receptor (FP) were isolated from the bovine corpus luteal cDNA library. The sequence analysis revealed that each FP isoform, respectively, encodes 325 (alpha), 326 (beta), 339 (gamma), 293 (delta), and 298 (epsilon) amino acid proteins, carrying the specific carboxyl tails (C-tails) caused by alternative mRNA splicing. Depending on the splicing sites, FP isoforms can be classified into two types. The FP-alpha, FP-beta, and FP-gamma belong to the same group (Type I), which has common amino acid sequences with the exception of each specific 4th intracellular C-tail, while FP-delta and FP-epsilon are classified into the second group (Type II), which has a truncated structure lacking transmembrane domain VII and an intracellular C-tail. The RT-PCR analysis indicated that the mRNAs for these isoforms are expressed at the same time with that of FP in the bovine corpus luteum during the estrous cycle and pregnancy.
