Effect of Hippophae rhamnoides Extract on Oxidative Oropharyngeal Mucosal Damage Induced in Rats Using Methotrexate

OBJECTIVES: The objective of this study is to investigate and evaluate the effect of Hippophae rhamnoides extract (HRE) on oropharyngeal mucositis induced in rats with methotrexate (MTX) through biochemical, gene expression, and histopathological examinations. METHODS: Experimental animals were divided into a healthy group (HG), a HRE+MTX (HREM) group, HRE group (HREG), and a control group that received MTX (MTXG). The HREM and HREG groups of rats was administered 50 mg/kg HRE, while the MTXG and HG groups were given an equal volume distilled water with gavage. Then, the HREM and MTXG rat groups were given oral MTX at a dose of 5 mg/kg 1 hour after HRE and distilled water was administered. This procedure was repeated for 1 month. At the end of this period, all of the animals were sacrificed with a high dose of anesthesia. Then, the amounts of malondialdehyde (MDA) and total glutathione (tGSH) were determined in the removed oropharyngeal tissues. Interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) gene expressions were measured, and all the tissues were studied histopathologically. RESULTS: The amount of MDA was significantly increased in the MTXG group compared to the HREM, HREG, and HG groups (P<0.001). MTX significantly decreased the amount of tGSH in the MTXG group compared to the HREM, HREG, and HG groups (P<0.001). In this study, there were no visible ulcers in the animal group in which the levels of MDA, IL-1β, and TNF-α were high and the level of tGSH was low. However, histopathologic examination revealed mucin pools in wide areas due to ruptured oropharynx glands, and proliferated, dilated, and congested blood vessels and dilated ductal structures in some areas. CONCLUSION: HRE protected oropharyngeal oxidative damage induced by MTX. As an inexpensive and natural product, HRE has important advantages in the prevention of oropharyngeal damage induced by MTX.