Modulatory Effects of Nano-Selenium Supplementation along with High Intensity Interval Training on Dexamethasone-Induced Liver Metaflammation

Background: Dexamethasone, a synthetic glucocorticoid, is widely used in clinical practice for various ailments. However, its use is associated with detrimental effects on the liver, including inflammation and oxidative stress. Selenium, an essential trace element, may serve as an effective ergogenic aid by enhancing anti-inflammatory and antioxidant properties, while high-intensity interval training (HIIT) has been shown to improve liver health. Objectives: The current study aimed to investigate the modulatory effects of selenium supplementation and HIIT on dexamethasone-induced liver inflammation in rats. Methods: Forty male Wistar rats (aged 6 - 8 weeks, 150 - 190 g) were randomly assigned to five groups (n = 8 per group): (1) Normal control (NC), (2) dexamethasone control (DC), (3) dexamethasone + high-intensity interval training + saline (DT), (4) dexamethasone + selenium supplement (DS), and (5) dexamethasone + selenium supplement + high-intensity interval training (DST). The training groups performed HIIT at a velocity of 24 - 34 m/min (~85% - 100% VO2max) for four weeks (5 days/week). Supplement groups received 100 mg of selenium (on odd days) via oral gavage. Inflammatory induction was achieved through subcutaneous injection of dexamethasone (0.4 mg/kg for 3 days). Gene expression levels of interleukin-4 (IL-4) and interleukin-5 (IL-1β) in liver tissue were determined using real-time PCR. Data were analyzed using one-way analysis of variance (ANOVA) and Bonferroni post hoc tests (P < 0.05). Results: Four weeks of dexamethasone supplementation significantly downregulated the inflammatory markers IL-4 (P = 0.077) and IL-1β (P = 0.029). Subsequently, HIIT and selenium supplementation were associated with significant modulation of IL-4 and IL-1β (P < 0.05). According to the Bonferroni results, HIIT combined with selenium supplementation had the greatest impact on the modulation of inflammatory markers in liver tissue. Conclusions: These findings suggest that selenium supplementation combined with HIIT can effectively improve inflammatory conditions in individuals suffering from liver metaflammation.