Comparison of the protective effects of Scrophularia striata extract with vitamin E on cognitive function, anxiety and pain sensitivity in diazinon-exposed male rats

Scrophularia striata is used in traditional medicine to treat various disorders and has neuroprotective effects. There are no studies about the effects of S. striata on cognitive functions in diazinon (DZN)- exposed rats. According to the results of previous studies, vitamin E (Vit. E) can also act as a protective agent against cognitive impairments. Therefore, the present study was designed to compare the effects of Vit. E and S. striata on DZN-induced behavioral impairments in male rats.

Neuroprotective effects of S. striata (30mg/kg, 5 days/week for 8 weeks) and Vit. E (200mg/kg, 5 days/week for 8 weeks, IP) were assessed through changes in memory, anxiety-like behaviors and pain threshold following DZN exposure. Open field, shuttle box and hot plate were used to examine anxiety-like behaviors, passive avoidance learning and memory as well as pain sensitivity, respectively.

Our findings indicated that exposure to DZN caused a significant decrease in memory retention and an increase in anxiety-like behaviors. S. striata and Vit. E administration compensated memory and emotional impairments induced by DZN. As well as, S. striata alone decreased reaction time against thermal stimulus in the hot plate test. The findings of the present study also indicated that exposure to DZN significantly decreased body weight, while S. striata and Vit. E consumption restored it.

Results of our study indicated the protective effects of S. striata consumption like Vit. E against DZN-induced disruptions in anxiety, cognitive function and body weight loss.