Evaluation of the effect of chamomile extract on lingual histological changes in rabbit received 5-fluorouracil (histological and immunohistochemical study)

* Department of Oral Diagnosis, College of Dentistry, Hawler Medical University, Erbil, Iraq. ** Department of Oral and Maxillofacial Surgery, College of Dentistry, Hawler Medical University, Erbil, Iraq. Department of Oral Diagnosis, College of Dentistry, Duhok University, Duhok, Iraq. Introduction Most treatments used to kill cancer cells also kill a diverse range of normal cell types, leading to a broad range of adverse side effects like mucositis. Mucositis is inflammation of the mucous membrane, and it is commonly seen in radiation therapy as well as a patient receiving chemotherapy, the incidence varies according to the type of cancer and treatment modality. It affect about 40 80% of patients treated with chemotherapy and almost all those receiving radiotherapy of the head and neck. 5-Flurouracil in general used for treatment of malignant tumors, particularly of the breast, rectum or colon and in the treatment of uterine, primary hepatic, pancreatic, gastric, ovarian, and bladder carcinomas. The 5-FU is one of the most common causes of oral mucositis, and due to its structure, 5-FU interferes with nucleoside metabolism and can be integrated into DNA and RNA, leading to cytotoxicity and cell death. Oral mucositis may results in discontinuation of chemotherapy or unplanned treatment. One of the widely used herbs for medicinal purposes is Background and objective: Chamomile has been used as an herbal medication since ancient times and is still popular until today. This study aimed to investigate the potential anticytotoxic effect of chamomile extract on the lingual mucosa of rabbits treated with 5-fluorouracil (5-FU). Methods: Thirty six rabbits were used in the study. For induction of tongue mucositis for the study group, 5-FU at a dose of (4 mg/kg) was administered intraperitoneally one time daily for five successive days. The control animals were intraperitoneally injected by normal saline one time daily for five successive days. The rats in each group were randomly divided into two groups: Distilled water and chamomile extract treated groups (9 animals each). A volume of distilled water equal to chamomile extract was given by gavage tube, while the other group was gavaged with chamomile extract at a dose of (100 mg/ kg) one time daily. The treatment with distilled water or the chamomile extract was continued for sixteen days and then the animals were sacrificed, and the tongues were excised for histopathological and immunohistochemical analysis. Results: The 5-FU/water treated group showed a significant increase in histological damage scores, decrease in the ki-67and increase in caspase -3 epithelial immune expression (P <0.05) in comparison with saline/water treated group. The 5-FU/chamomile treated group showed a significant increase in damage score, significant decrease in ki-67 immune expression and significant increase in caspase-3 immune expression (P <0.05) in comparison with 5-FU/water treated group. Conclusion: Chamomile extract at a dose of (100 mg/ kg) one time daily for sixteen days cannot be used for the treatment of oral mucositis. It causes damage to the tissue, decreases proliferation, and increases apoptosis.