Subchronic Residual Oil Fly Ash (ROFA) exposure induces oxidative stress in brain, lung, and cardiac tissues and promotes neuroinflammation, with partial attenuation by taurine.

BACKGROUND: Exposure to particulate matter (PM₂.₅), including Residual Oil Fly Ash (ROFA), triggers oxidative stress and inflammation. Taurine, an antioxidant amino acid, may protect against these effects, but its efficacy against subchronic ROFA exposure is unclear. This study evaluated taurine's protective role in ROFA-induced multi-organ damage and neurobehavioral changes. METHODS: Male Wistar rats received ROFA (250 µg/day, intranasally) for six weeks, with or without taurine (400 mg/kg/day). Oxidative markers (CAT, SOD, TBARS) were measured in the brain, lungs, heart, and liver. Cytokines (TNF-α, IL-1β) were assessed in plasma and brain. Behavior was tested using Open Field, Elevated Plus Maze, and Novel Object Recognition. RESULTS: ROFA increased oxidative stress, reducing catalase in the brain and lungs and raising TBARS. Neuroinflammation was evident via elevated TNF-α and IL-1β and confirmed by histopathology, which revealed Gitter cells and endothelial hypertrophy. ROFA also raised urea levels and caused pulmonary damage. Behaviorally, ROFA increased locomotion (distance traveled and line crossings) without altering anxiety or memory. Taurine attenuated oxidative stress in the liver and kidneys. While taurine treatment alone increased vertical exploratory behavior (rearing), it did not significantly reverse the behavioral or neuropathological changes induced by ROFA exposure. CONCLUSIONS: Subchronic ROFA exposure causes multi-organ damage, predominantly in the brain and lungs. Histopathological evidence confirmed significant neuroinflammation. Taurine provides partial, organ-specific protection against oxidative stress but has limited efficacy against neuroinflammation. These findings suggest taurine's benefits are context-dependent, highlighting the need for further research into its mechanisms and potential in combating air pollution-related health effects.