Impact of buprenorphine on learning and memory ability, oxidative status and inflammation in the hippocampus of rat

Background: Buprenorphine (BUP) a "synthetic derivative of the opioid alkaloid thebaine" may be associated with cellular damage in the central nervous system.

Aims: This study was designed to investigate the effects of low and high doses of BUP on oxidative and inflammatory indices in the hippocampus and learning and memory behavior in an animal model.

Objective: The association between BUP administration and oxidative and inflammatory damage and also learning and memory impairment is not clear.

Method: For this reason, twenty four male Wistar rats were randomly allocated in to one control and two BUP-treated groups (0.3 and 1 mg/kg, SC), (n=8, for each group). After 4 weeks, learning and memory abilities were assessed by using Y-maze test. Then, oxidative stress indices including glutathione (GSH), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) were assessed in the serum and hippocampus of each animal by using spectrophotometer. Inflammatory parameters such tumor necrotic factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) were also measured in the serum and hippocampus of rats by using ELISA.

Results: The present findings indicated that the memory and learning time was lengthened in BUP (1mg/kg)-treated rats versus control animals (p<0.05). Additionally, it was observed that BUP (1 mg/kg) significantly increased the serum and hippocampal levels of MDA and TNF-α and also decreased GSH levels versus the control group (p< 0.05).

Conclusion: The present results reveal that BUP may cause learning and memory dysfunction via inducing oxidative stress and inflammation in hippocampus.

Keywords: Buprenorphine; learning; hippocampus.; inflammation; memory; oxidative stress.