Bhilawanol ameliorates morphine condition place preference and anxiety-like symptoms during the abstinence period

Opioid addiction is accompanied by persistent drug seeking and a high relapse rate even during prolonged periods of abstinence. The main objective of addiction treatment is to prevent relapse, which remains the primary limitation of the current pharmacological therapy. In the present work, the role of Bhilawanol (BWL), a naturally occurring compound, on morphine (MOR) condition place preference (CPP) and the anxiety-like behavior during the abstinence period in the mice model was investigated. MOR-CPP was induced with an increasing dose of intraperitoneal (i.p.) MOR 5 mg/kg bid to 25 mg/kg bid for 5 days during the conditioning schedule. The pharmacological effects of BWL (0.25, 0.5, and 1 mg/kg i.p.), were tested on the rewarding effects of MOR. BWL 1 mg/kg significantly reduced MOR acquisition and reinstatement, while accelerated extinction to MOR CPP. The anxiety-like behavior on the last extinction day was also markedly reduced with BWL 1 mg/kg as evaluated by the Open-field (OF) and elevated plus maze (EPM) test. The antioxidant assay showed that BWL significantly preserved the protective activity of the enzymes Glutathione-S-Transferase (GST), reduced glutathione (GSH), and catalase (CAT), and reduced the lipid peroxidation (LPO) in both the cortex and hippocampus regions of the brain. The immunohistochemistry revealed the protective effect of BWL on the expression of TNF-α, p-NF-κB, iNOS, and nNOS in both cortex and hippocampus regions of the brain. Further, BWL also modulated the expression of the TNF-α and BDNF in MOR-treated mice as measured through ELISA. In addition, the BWL displayed a significant reduction in the mRNA expression of iNOS and nNOS genes in the hippocampal region of the mice brain. These findings show the beneficial effects of BWL in MOR CPP, extinction, and reinstatement, as well as reducing anxiety during abstinence to MOR through modulation of antioxidant, inflammatory, and NO pathways.