Histopathological and Biochemical Investigations of the Brain upon Sub-Acute Pentazocine Administration

Objective: Despite its common use among sickle-cell disease patients, pentazocine addiction in Nigeria has become a health concern among youths battling with diverse forms of pain. This study aimed to evaluate the toxicological effects of pentazocine on the cerebral cortex.

Methods: Twenty-eight (28) adult Wistar rats were acclimatized and grouped into four. Group 1 (control) was administered 1ml of normal saline (0.9% NaCl) while groups 2 – 4 served as the experimental groups and administered graded doses of 30 mg/kg, 60 mg/kg, and 90 mg/kg pentazocine (PZ) intramuscularly for 14 days. Brain tissues were obtained and analyzed for biochemical parameters such as catalase (CAT), superoxide dismutase (SOD), and malondialdehyde (MDA), as well as histopathological analyses of sample tissues. A one-way analysis of variance (ANOVA) was used to analyze the differences between the groups using the Statistical Package for Social Sciences (SPSS) version 23.0.

Results: In PZ-treated groups, the activities of CAT and SOD in the brain decreased while MDA levels increased (p < 0.05). The cerebral cortex of PZ-treated groups showed granular cell aggregations, moderate neuronal cell loss, and pyramidal cell loss.

Conclusion: Sub-acute pentazocine administration was shown to cause moderate toxicity and could lead to brain inflammatory responses.