Cannabidiol Modulation of Nicotine-Induced Toxicity: Assessing Effects on Behavior, Brain-Derived Neurotrophic Factor, and Oxidative Stress in C57BL/6 Male Mice

Abstract

High doses of nicotine administered to rodents serve as a model for studying anxiety and test compounds' potential anxiolytic effects. At these doses, anxiety in rodents is accompanied by disruption of brain-derived neurotrophic factor (BDNF). The endocannabinoids and nicotine modulate several central nervous system processes via their specific receptors, impacting locomotion, anxiety, memory, nociception, and reward. Cannabidiol (CBD), an active ingredient of Cannabis sativa L., is devoid of psychoactive actions and has gained attention for its anxiolytic, antioxidant, and anti-inflammatory properties, among others. This work aims to examine the potential anxiety-reducing properties of CBD in a well-established experimental mouse model of anxiety-like behavior induced by high doses of nicotine on male C57BL/6 mice. In this context, the open-field behavioral test was specially conducted to assess CBD's effects on anxiety-like behavior and locomotion. Brain neuronal plasticity, modulated by BDNF, along with a diverse array of blood's metabolic markers, was examined as a means of evaluating systemic toxicity under various treatments. Finally, oxidative stress was evaluated through the measurement of glutathione (GSH), superoxide dismutase (SOD), and malondialdehyde (MDA), while pro-inflammatory cytokine assessments were conducted to evaluate redox status and immune system function. Our research suggests that CBD shows potential in reducing anxiety-like behaviors induced by high doses of nicotine, by mitigating changes in BDNF protein levels in cerebral hemispheres and cerebellum. At the same time, CBD targets specific liver enzymes, maintains tissue's systemic toxicity (i.e., renal, kidney, and pancreatic), balances redox status (SOD, GSH, and MDA), and regulates the secretion of pro-inflammatory cytokines (TNF-alpha and IL-6).