Background: Duloxetine is an antidepressant drug utilized for treatment of anxiety disorders and depressive disorders. This study aimed to compare the potential protective effect of Rosmarinic acid (RA) as natural antioxidant with the potential therapeutic effects of mesenchymal stem cells on treating the toxic effect of Duloxetine on the parotid gland. Material & methods: 60 male albino rats were classified into 4 groups, 15 rats in each group. The first group1 (control): negative control (group 1a) formed from 7 rats received no treatment, positive control (group 1b) formed from 8 rats received 1ml distilled water using oro-pharengeal tube for 12 weeks, group 2 (Duloxetine): received 10 mg/kg/d duloxetine dissolved in distilled water using oro-pharengeal tube for 12 weeks, group3 (Duloxetine+RA): received Duloxetine the same as Group2 and received at the same time 120 mg/kg/d Rosmarinic acid dissolved in distilled water for 12 weeks using oropharengeal tube, group4 (Duloxetine+MSCs): received Duloxetine the same as Group2 then a single injection of MSCs just after stopping of Duloxetine , In all groups animals were sacrificed after 16 weeks for histological evaluation, the parotid gland was stained with hematoxylin and eosin, and Mallory's trichrome stain. Also, Transmission electron microscope and immunohistochemistry using caspas-3 were used to examine the parotid gland. Also the level of MDA and GSH-Px level in the parotid tissue were done. Results: Examination of parotid sections in Group2 revealed inflammatory cells infiltration and massive distortion and vacuolation of serous cells, however Group3 and Group4 showed marked improvement in the histological structure of the parotid gland. Conclusion: MSCs and RA have good effect in decreasing the toxic effect of Duloxetine administration on the parotid gland with insignificant difference between the two methods.

Five-fluorouracil (5-FU) is an effective chemotherapeutic medication. It is commonly implicated in treatment of various malignancies; this research aimed to investigate potential therapeutic effect of the BMMSCs and Astaxanthin on 5-FU toxic effect on albino rat's stomach. 40 rats were divided into 4 groups: Group I (control group): received no treatment Group II (5-fluorouracil group): for 5 consecutive days rats were intravenously injected by 50 mg/kg 5-FU. Group III (5-Fluorouracil group and Astaxanthin): got 5-FU as in group II, followed by astaxanthin 50mg/kg for 10 consecutive days. Group IV (BMMSCs): received 5-FU as in group II then intravenously injected by 10 6 of BMMSCs once in rat tail. All rats were sacrificed on the 35 th day from the beginning of the experiment, to be examined microscopically, stomach sections were stained by H&E to evaluate histopathological changes, stained also with PAS to evaluate mucosal glycoprotein production, transmission electron microscopic was used to evaluate ultra-structural changes and Immunohistochemistry using Ki67 was used to evaluate level of cell proliferation. examination of stomach Sections of group II showed separation in the gastric glands, congested blood capillary, vacuolations of parietal cells, while (Gr III) and (Gr IV) showed marked stomach histological structure improvement and down regulated expression of Ki67, compared to the (GrII). Electron microscope supported these results. Both BMMSCs and Astaxanthin have good impact in ameliorating the toxic effect of 5-FU on albino rats stomach, with no significant difference between both techniques.