Effects of oligonol on the submandibular gland in ovariectomized rats

The aim of this study was to observe the effects of oligonol on submandibular gland dysfunction in ovariectomized rats. We randomly divided female Sprague-Dawley rats into sham-operated, ovariectomized, and oligonol-treated ovariectomized groups. Oligonol was intraperitoneally administered at 30 mg/kg daily for six weeks. Lipogenesis increased after the ovariectomy while fatty acid oxidation increased and intracellular triglyceride levels decreased in response to oligonol treatment. Submandibular gland fibrosis characterized by collagen type I accumulation was observed in the ovariectomized group. However, oligonol markedly reduced fibrosis to a level comparable to that observed in the sham group. Aquaporin 1 and glucose transporter 4 were downregulated in the ovariectomized group. Nevertheless, both factors were significantly upregulated by oligonol treatment. However, aquaporin 5 was significantly downregulated in the oligonol treatment group. Our findings indicate that oligonol protects against damage in postmenopausal rat salivary glands.