The aim was to determine the effect of Sechium edule var. nigrum spinosum (chayote) on gene ex-pression related to antioxidant protection mechanisms and the inflammatory process in older adults with metabolic syndrome (MetS). A quasi-experimental study was carried out in a con-venience sample of 46 older adults diagnosed with MetS: (i) placebo group (PG; n=20), (ii) ex-perimental group (EG; n=26). Clinical, biochemical, and anthropometric parameters, SOD, GPx, and CAT enzyme activity, total oxidant status (TOS), total antioxidant status (TAS), oxidative stress index (OSI), cytokines (IL-6, IL-8 and TNF-α) and mRNA expression of (SOD, GPx, CAT, IL-6, IL-8, TNF-α, Nrf2, NFkB p50 and NFkB p65), were measured at baseline and 6 months post-intervention. A statistically significant decrease was observed in TOS (baseline, 28.9 ± 3.6 vs. post, 23.7 ± 3.4, p < 0.01) and OSI (baseline, 24.1 ± 3.8 vs. post, 17.7 ± 4). As well as the increase in IL-6 (baseline, 10.7 ± 1.1 vs. post, 12.3 ± 2, p = 0.03), SOD activity (baseline, 167.1 ± 11.9 vs. post, 180.6 ± 7.6, p < 0.05), CAT activity (baseline, 1.0 ± 0.2 vs. post, 1.3 ± 0.2, p < 0.01) and TAS (baseline, 1.1 ± 0.1 vs. post, 1.4 ± 0.1, p < 0.01) in the EG compared to the PG. Regarding the expression of Nrf2, SOD and IL-6, the EG showed a significant increase vs basal levels (47%, 44% and 43%, re-spectively). Our findings suggest that Sechium edule supplementation promotes the antioxidant response and decreases oxidative stress via Nrf2.
