Quercetin Improves Cognitive Function by Ameliorating Histopathological Changes and Inflammation in Di(2-ethylhexyl) Phthalate-Exposed Mice.

Background/

Objectives

Phthalates are a group of organic compounds widely used for enhancement in flexibility and transparency of polyvinyl chloride (PVC) products. Exposure to phthalate-containing substances has been shown to affect brain function, particularly in learning and memory processes. Quercetin is a plant-derived flavonoid with remarkable anti-oxidant and anti-inflammatory potential. This study investigated the possible protective effects of quercetin on spatial learning and memory, histomorphometric changes, and hippocampal expression of inflammatory cytokines (TNF-α and IL-6) in male mice exposed to di(2-ethylhexyl) phthalate (DEHP).

Methods

A total of 42 male mice were divided into seven groups. Quercetin was administered orally at doses of 25 and 50 mg/kg/day, either alone or in combination with DEHP (200 mg/kg/day). Following the final day of the treatment, spatial learning and memory were assessed by the Morris Water Maze test. Hippocampal tissues were sampled for Nissl, H&E, and immunofluorescence staining. Quantitative real-time PCR was used to measure the expression of TNF-α and IL-6.

Results

The DEHP group exhibited significant impairments in learning and memory, neuronal damage, and cellular disorganization in the hippocampus, along with increased astrocyte activation and elevated expression of TNF-α and IL-6. On the other hand, quercetin supplementation significantly reduced these inflammatory markers and histological damages and also improved spatial learning and memory.

Conclusions

Overall, quercetin improves cognitive function that is associated with attenuating astrocyte activation and inflammation.