Estrogen versus bone marrow mesenchymal stromal cells in the regeneration of the parotid gland in ovariectomized rats.

Menopause causes specific hormonal alterations in women that make them more susceptible to salivary changes, such as decreased saliva flow, which can lead to xerostomia, modified taste, and a burning sensation in the mouth. This study aimed to determine which of two treatments-bone marrow-derived mesenchymal stromal cells (BM-MSCs) or estrogen-more effectively ameliorate the postmenopausal degenerative effects on the parotid salivary glands of ovariectomized rats by histological, immunohistochemical, and malondialdehyde (MDA) evaluations. The study specimen involved 70 female albino rats. Group I received saline, and were subdivided into sham-operated and vehicle-treated. Group II was subjected to bilateral ovariectomy and received no treatment. Group III was subjected to bilateral ovariectomy and, one week later, treatment with subcutaneous injections of 1 mg/kg/daily estrogen for 12 weeks. Group IV underwent bilateral ovariectomy and, one week later, received a single intraglandular injection of a BM-MSC solution. At the end of the experiment, the rats were euthanized, and their parotid glands were dissected and processed for H&E stain, caspase 3, and MDA evaluations. The histological and immunohistochemical findings in Group II showed marked degenerative changes in the parotid gland. However, in Groups III and IV, regeneration was observed following treatment with estrogen and BM-MSCs, respectively. The estrogen and BM-MSCs groups showed significant decrease in MDA levels in the parotid gland relative to the ovariectomized group and nearly comparable to control. BM-MSCs and estrogen show histological efficacy in regenerating the parotid salivary glands of ovariectomized rats.