Abstract

This study evaluated the antioxidative and antiapoptotic effects of chlorophyllin (CHL) on a rat spleen exposed to localized gastric radiotherapy. The stomach region of female rats was exposed to 300 kV X-rays at a dose rate of 2.8 Gy/min either alone or co-treated with oral intake of CHL (15.0 mg kg^-1BW) for 4 days. The Catalase (CAT) and Superoxide Dismutase (SOD) activities and Malondialdehyde (MDA) concentrations in the spleen homogenates were conducted. The splenic tissue was examined histologically while localization of CD3, B220, Iba1, PCNA, ss- DNA, IL-1β and TNF-α was determined immunohistochemically. Morphometrical measurements of the indices of proliferative cells and apoptotic cells were done with image J software. For data analyses, ANOVA's method followed by Tukey’s test was applied for multiple comparisons. In radiated group, a significant decrease in CAT and SOD and a significant increase in MDA were recorded. Histopathologically, cellular depletion of the germinal center and appearance of the apoptotic bodies and tingible body macrophages were noted. Statistically, a significant decrease (0.32 ± 0.020 P˂0.05) in the index of proliferative cells and a significant increase in the index of apoptotic cells (0.62 ± 0.034 P˂0.05) were detected. Administration of CHL reversed the oxidative stress levels as evidenced by significant increases of the antioxidant biomarkers and a significant decrease of the oxidant biomarker. In addition, structural and immunohistochemical ameliorations were proved via increased cellular proliferation (0.56 ± 0.032 P˂0.05) and decreased apoptosis (0.13 ± 0.010 P˂0.05). In conclusion, localized radiotherapy is not safe on neighboring organs. Adding of CHL modulated the radiotherapy damage. Maintenance of regular dietary consumption of CHL is recommended during localized radiotherapy to provide a constant supply of potent antioxidants that might prevent any alterations.

Keywords: Antioxidants; Cytokines; T cells; X-rays