The brain and systemic oxidative stress and memory changes induced by inhaled paraquat in rat improved by Crocus sativus

The present study aimed to investigate the effect of Crocus sativus (Cs) on paraquat (PQ)-induced learning and memory deficits as well as brain and lung oxidative stress and systemic inflammation, and oxidative stress in rats.

Rats were exposed to saline (Ctrl) or PQ (PQ groups) aerosols. PQ groups were treated with 0.03 mg/kg/day dexamethasone (Dexa), 20 and 80 mg/kg/day Cs-L and Cs-H, 5 mg/kg/day pioglitazone (Pio), and Cs-L+Pio for 16 days during PQ exposure period. Learning and memory abilities were assessed by Morris water maze (MWM) and passive avoidance tests.

PQ group showed increased numbers of total and differential WBCs in blood, and increased malondialdehyde (MDA), in the serum, brain, and lung but reduced thiol, catalase (CAT), and superoxide dismutase (SOD) levels compared to the control group (for all, p < 0.001). The escape latency and traveled distance were increased in the PQ group. However, the time spent in the target quadrant in the MWM test and the latency to enter the dark room were reduced after receiving an electrical shock (p < 0.05 to P<0.001). In all treated groups, measured values were improved compared to PQ group (p < 0.05 to p < 0.001). The combination of Cs-L+Pio showed more pronounced effects compared to either treatment alone (p < 0.05 to p < 0.001).

These findings suggest that Cs has neuroprotective properties and may be beneficial in the treatment of neurodegenerative diseases induced by noxious agents such as PQ.