Neurobehavioral and metabolic effects of polyphenol-rich olive oil in male rats during the adolescent-to-young adult transition: a comparative study

Abstract

Adolescence and the transition to young adulthood represent critical periods for brain development, marked by increased susceptibility to neuroinfammation and metabolic disturbances. Olive oil polyphenols are known for their antioxidant and anti-infammatory properties, yet their specifc efects on neurobehavioral outcomes during this developmental window remain unclear. This study aimed to compare the efects of high-polyphenol olive oil (HPOO) and low-polyphenol olive oil (LPOO) on neuroinfammatory markers, lipid profles, cognitive performance, and emotional behaviors in male Sprague Dawley rats aged 6–14 weeks. Twenty-four animals were randomly assigned to control, LPOO, or HPOO groups and received oral gavage for 8 weeks. Behavioral assessments included the Morris water maze (MWM), open-feld test (OFT), elevated plus maze (EPM), and forced swim test (FST). Serum triglycerides, LDL/HDL ratio, and cytokine levels in the hippocampus and prefrontal cortex were evaluated via ELISA. HPOO signifcantly reduced triglyceride levels and LDL/HDL ratio, while LPOO lowered only triglycerides. HPOO also decreased the TNF-α/IL-10 ratio in both brain regions, suggesting reduced neuroinfammation, whereas LPOO showed efects limited to the prefrontal cortex. Elevated TG and TNF-α/IL-10 levels were positively correlated with anxiety-like behaviors and inversely related to spatial memory performance. These fndings indicate that HPOO has superior modulatory efects on neuroinfammatory and metabolic parameters compared to LPOO. Regular consumption of HPOO may support neurodevelopmental health during adolescence and early adulthood by reducing infammation and improving lipid balance, potentially contributing to improved emotional and cognitive outcomes.