Regular moderate-intensity exercise can increase the effectiveness of the body’s endogenous antioxidants, and potentially boost immune defenses against viral infections. The bioflavonoids in lemon peel essential oil, known for their antioxidant properties, also help protect against free radical damage while acting as immunomodulators. This study aimed to evaluate the potential benefits of consistent moderate exercise and lemon peel essential oil on the immune response during the COVID-19 pandemic. The study involved randomly dividing 20 white rats into two groups, each consisting of 10 animals. Group P1 participated in 40-minute moderate-intensity swimming sessions, while group P2 underwent the same swimming routine and also received 0.05 milliliters of lemon peel essential oil per hour before the swimming sessions. The results showed that in the RDF group, the total antioxidant capacity (TAC) increased from 320.34 ± 44.05 µmol (pre-test) to 353.01 ± 70.22 µmol (post-test), and the C-reactive protein (CRP) level decreased from 0.54 ± 0.11 ng/ml (pre-test) to 0.49 ± 0.04 ng/ml (post-test). Similarly, the RE group experienced an increase in TAC from 338.15 ± 29.14 µmol (pre-test) to 356.48 ± 44.34 µmol (post-test) and a decrease in CRP levels from 0.56 ± 0.04 ng/ml (pre-test) to 0.53 ± 0.09 ng/ml (post-test). However, no statistically significant differences were observed in TAC (P > 0.05) or CRP (P > 0.05) levels after the exercise, and no significant differences were observed between the two groups (P > 0.05).
