Abstract
This study evaluated the effects of dietary Echinacea purpurea supplementation on immune regulation, oxidative stress, and cellular aging in broiler chickens reared at high altitude (2100 m). One hundred and eight day-old male Ross 308 broiler chicks were randomly allocated to three dietary treatments: a control diet, a diet supplemented with 0.25% E. purpurea (E0.25), or a diet supplemented with 0.75% E. purpurea (E0.75), and reared for 42 days. At the end of the trial, hepatic gene expression of IL10, IL1β, TNFα, and IFNγ was analyzed, along with plasma malondialdehyde and nitric oxide levels and relative liver telomere length. Dietary E. purpurea markedly enhanced immune responsiveness, significantly upregulating IFNγ (by approximately 870-890%) and IL10 (by approximately 320-360%) expression without altering IL1β or TNFα expression. In contrast, E. purpurea supplementation did not affect nitric oxide production or telomere length based on the markers measured. Regarding the oxidative stress indicators assessed, the higher inclusion level (0.75%) significantly increased plasma malondialdehyde concentration, indicating a pro-oxidant effect. In conclusion, E. purpurea exerts a strong and balanced immunomodulatory effect in broilers reared under high-altitude conditions; however, based on the present measurements (MDA and NO), it did not improve the measured oxidative stress parameters and may induce lipid peroxidation as reflected by plasma MDA at higher doses. Therefore, based on the measured parameters, the 0.25% inclusion level appears potentially safer and immunomodulatory, warranting further investigation before practical application under high-altitude conditions.