Attenuating Effects of α-tocopherol on Cytarabine-Induced Toxicity in Parotid Salivary Gland of Rabbits: A Histological and Immunohistochemical Study

Background: Cytarabine is considered a cornerstone of treating acute leukemia. Xerostomia is among the adverse effects that can dictate treatment cessation or the use of some agents that decrease its cytotoxic effects.Objectives: This study aims to identify the histological effects of cytarabine on the rabbits’ parotid gland and to assess the ameliorating α–tocopherol impact on these effects.Methods: The study rabbits were separated into ۴ groups. Group A (control) was given ۱ mL of intraperitoneal (IP) injection of normal saline/day for ۱۰ days. Group B received α-tocopherol (۸۰۰ IU) by gavage for ۱۰ days. Group C received cytarabine (۶۰ mg/kg/d) IP for ۱۰ days. Group D received α-tocopherol (۸۰۰ IU) by gavage before injection of cytarabine (۶۰ mg/kg) at the same time for ۱۰ days. The rabbits were euthanized, and tissue preparation for analyzing microscopically and immunohistochemically for B-cell lymphoma ۲ (Bcl-۲) and tumor-necrosis-factor (TNF)-α was achieved. Results: Microscopically, group B’s parotid salivary gland sections revealed increased thickness of connective tissue of the trabeculae, degeneration, and necrosis of serous acini cells with aggregation of inflammatory cells. In contrast to the histopathological alteration of the glands in group C, which is characterized by intact serous acini, intercalated duct, and normal thickness of trabeculae, in the cytarabine group, TNF-α immunohistochemical expression was of grade ۳ and in the cytarabine with α-tocopherol group was of grade ۱. The Bcl-۲ immunohistochemical expression in the cytarabine group was of grade ۰, and in the cytarabine with α-tocopherol group was of grade ۱. Conclusion: α-Tocopherol decreases cytarabine toxicity in the rabbits’ parotid salivary glands.

Keywords:

α-tocopherol , Bcl-۲ , Cytarabine , Parotid salivary gland , TNF-α