vitamin c mitigates radiation-induced parotid glands inflammation by downregulating tnf-α and il-1β expression in guinea pigs

Background: radiation therapy damages surrounding tissues, with parotid glands being highly vulnerable in the head and neck region. antioxidant and anti-inflammatory properties of vitamin c may reduce radiation-induced injury. this study therefore investigated the impact of vitamin c on morphological and histological changes in guinea pig parotid glands and its impact on tumor necrosis factor-alpha (tnf-α) and interleukin-1 beta (il-1β) expression.method: 48 dunkin hartley guinea pigs (6-8 months, both sexes) were divided into four groups: control, vitamin c (3 mg/kg), radiation 8 grays (gys), and radiation + vitamin c. animals were treated with radiation and/or vitamin c for 15 days on alternate days. weight and saliva volume were measured on alternate days too. parotid glands were extracted for histological and immunohistochemical analysis of tnf-α and il-1β. data were analyzed using spss (version 21) and presented as mean ± standard error of mean. one-way anova with bonferroni's post hoc test was applied, with p < 0.05 considered significant.results: over 15 days, no significant differences in animal weight were observed (p > 0.05). however, a significant reduction in saliva production occurred in the radiation group, alleviated by vitamin c (p < 0.05). histological analysis showed radiation-induced inflammation in the parotid glands, which was diminished by vitamin c. immunohistochemistry revealed a significant increase in tnf-α and il-1β expression in the radiation group (p < 0.001), with vitamin c significantly downregulating both markers in the radiation + vitamin c group (p < 0.001).conclusion: vitamin c may protect against radiation-induced parotid gland inflammation by downregulating tnf-α and il-1β, suggesting its potential as a therapy for radiation-induced tissue injury.