IMPACT OF BONE MARROW STEM CELLS APPLICATION ON THE METHOTREXATE INDUCED SUBMANDIBULAR SALIVARY GLAND DEGENERATIVE CHANGES IN ALBINO RATS (HISTOLOGICAL AND IMMUNO-HISTOCHEMICAL STUDY)

Introduction: cytotoxic drugs produce a structural changes in salivary glands that results in disturbances in their function. Patients treated with these cytotoxic drugs complain from xerostomia that results in difficulties in swallowing, speech, taste sensation, oropharyngeal pain and oral infections. Aim: This is study was conducted to evaluate the effect of local injection of bone marrow stem cells on submandibular glands of rats receiving Methotrexate as chemotherapeutic drug histologically and immunohistochemically.
Materials and Methods: Thirty male adult albino rats (150–200 gm). They were randomly divided into three groups (n=10). Group I: rats were received single intraperitoneal injection of Phosphate buffered saline PBS 1 ml at the day one of the experiment. Group II: rats received single intraperitoneal injection of 40 mg/kg Methotrexate (MTX) dissolved in 1ml saline at day one of the experiment. Groups III: rats were handled as those in group II; however, rats were subjected to intra glandular injection of bone marrow stem cells (BMMSCs) suspended in 0.1 ml PBS 7 days after the start of the experiment at both sides of submandibular salivary gland (SMG). Animals of all groups were euthanized at three weeks after the start of experiment and two pairs of (SMG) were dissected out, processed and the prepared sections were examined histologically by H&E, immunohistochemical stain for Bcl-2 and morphomtrical analysis. Data obtained from immunohistochemical analysis were statistically described in terms of mean ± standard deviation (± SD).
Results: Histological examination of Group I revealed the normal histological structure of the gland and mild positive immunoreaction of Bcl-2. Group II has glandular disorganization. The nuclei of the acinar cells revealed different sizes and shape (polymorphism) and negative immunoreactivity for Bcl-2. Group (III) revealed marked improvement in cells of acini as well as cells of ducts lining and the acini relatively preserved their shape with strong cytoplasmic immunoreaction of Bcl-2. The immunohistochemical results confirmed the previous results as the highest mean value of Bcl-2 expression was observed in group III, followed by the control group which showed the second highest Bcl-2 mean value. While, the lowest mean value was observed in group II. The difference among the examined groups was statistically significant where the
p-value was < 0.001.
Conclusion: The application of the MSCs could preserve salivary glands from apoptosis by the enhancement of the antiapoptotic activity and it could be used as a new strategy to decrease the harmful effects of methotrexate on submandibular gland tissue.