AIR POLLUTION IMPACT ON BRAIN: ANTIOXIDANT RESPONSE IN A RAT MODEL OF UNDERNUTRITION

MASCI, IVANA; LEZÓN, CHRISTIAN; BONETTO, JULIAN; BOYER, PATRICIA M; TASAT, DEBORAH R.; KURTZ, MELISA L.

Jornada; XXIII ANNUAL MEETING OF THE ARGENTINEAN BIOLOGY SOCIETY (SAB); 2021

Air pollution (gases and particulate matter- PM) can lead to central nervous system (CNS) neuroinflammation and neurodegeneration,which ultimately impair cognitive function, especially in children. Exposure to high levels of ambient PM is associated with neuro andvascular inflammation, being inflammation and oxidative stress two potential biological mechanisms for these adverse health effects.Metal-carrying particles that reach the brain can directly damage neurons and can also cause extensive harm by dysregulating theactivation of the immune cells in the brain. Furthermore, child malnutrition is recognized as a major problem with devastating effectson children’s health. Thus, children encompass a subpopulation highly susceptible to the adverse effect of environmental pollutants andvulnerable to malnutrition. Therefore, the aim of this study was to characterize morpho-chemically particles of Residual Oil Fly Ash(ROFA, an ambient air PM surrogate) and to evaluate, in the brain of malnourished rats, the possible oxidative effect caused by acuteexposure to ROFA. The morpho-chemical characterization was carried out by scanning electron microscopy (SEM) and energydispersive X-ray spectroscopy (EDX). For the nutritional growth retardation (NGR) animal model, Wistar male weanling rats weredivided at random in two groups. NGR animals, were fed for 4 weeks a restricted diet 20% compared to ad libitum intake of control (C)animals. NGR and C rats were intranasally instilled with either 1 mg/kg BW of ROFA or its vehicle. The brain was isolated, and theoxidative metabolism was spectrophotometrically measured. Antioxidant enzymes activity (catalase-CAT and superoxide dismutaseSOD) and lipoperoxidation (thiobarbituric acid reactive substances-TBARS) were assessed. ROFA proved to be heterogeneous both insize and shape, and its spectral composition confirmed that is mainly composed of amorphous carbon with metallic sulfates and metallicoxide materials, with significant quantity of heavy metals such as Ti, Zn, V, Cr, and Ni. Exposure to ROFA and chronic malnutritioncaused a decrease in antioxidant enzymes activity. NGR rats showed a lower capacity to respond to an oxidative stressor such as ROFAwhen compared to C. In conclusion, air pollution affects antioxidant defenses suggesting that oxidative stress could be in part a pathwayof air PM brain dysfunction in malnourished individuals.