A Survey of the Effects of Diosmin on Learning and Memory Following the Use of Paraquat Herbicide Poisoning in a Model of Rats

Abstract

Background: Exposure to herbicide paraquat (PQT) is a potential risk factor for cognitive impairment. Many cognitive behaviors, including spatial memory, passive avoidance, balance, and motor performance, may be affected by PQT. Objectives: This study aimed at determining cognitive behaviors, motor function, and malondialdehyde (MDA) content of the hippocampus after i.p. injection of PQT in rats and evaluating the effects of diosmin (DM) in preventing PQT effects on cognitive behaviors and MDA level in the hippocampus. Methods: In this study, 32 male Wistar rats were divided randomly into four groups: control, PQT (4 mL/kg), DM (100 mg/kg), and DM + PQT. PQT (4 mg/kg, i.p.) was used three times a day for one week to develop a cognitive deficit model. The rats were pretreated using DM (100 mg/kg) for seven days before PQT administration. Passive avoidance task (PAT), rotarod test, and spatial memory tests were also performed. The MDA level was measured in the hippocampus of different groups to determine lipid peroxidation. Results: Based on the findings, 100 mg/kg of DM increased the step-through latency, total time in the target quarter, and bar latency in the cognitive deficit model (P < 0.01 and P < 0.001, respectively). The hippocampal concentration of MDA was significantly lower in the DM + PQT group, compared with the PQT group (P < 0.001). Conclusions: DM could effectively prevent cognitive deficits (spatial memory and passive avoidance) and motor dysfunctions induced by PQT administration. In addition, MDA concentration reduced in the hippocampus was induced by i.p. injection of PQT. The present study suggests DM as a suitable compound for memory restoration in cases of PQT poisoning.