Evaluation of the effect of alpha-tocopherol on anxiety and the neuroinflammatory process during alcohol withdrawal in a model of forced and chronic self-administration of liquid diet containing ethanol: Behavioral and neurochemical evidence

Alcohol. 2022 Nov:104:31-44. doi: 10.1016/j.alcohol.2022.08.002. Epub 2022 Aug 17.

Abstract

Alcoholism affects about 2 billion people worldwide. Withdrawal causes a neuroinflammatory response that increases anxiety. α-tocopherol is the most important antioxidant that has its in vivo action currently known. Therefore, this study aimed to evaluate the effect of α-tocopherol on the neuroinflammatory process in brain regions involved in anxiety and its anxiolytic potential during alcohol withdrawal. For this, male Wistar rats were divided into four groups and submitted to a procedure of forced and chronic self-administration of liquid diet containing 6% and 8% ethanol for 15 days, followed by abrupt interruption of treatment. Animals in the control group received the liquid diet without ethanol. Twenty-four or 48 h after ethanol discontinuation, and 30 min after the last administration of α-tocopherol or saline, animals were evaluated in the elevated plus maze, light/dark box, and open field tests. At the end of the tests, each experimental group underwent brain tissue collection for analysis of cytokine levels. The results showed that: alcohol induces the neuroinflammatory process and anxiety; the stress generated by withdrawal can induce oxidative stress, which alters the production of inflammatory cytokines in the amygdaloid nuclei (AN) and medial hypothalamic nucleus (mHN); α-tocopherol exhibited anxiolytic and anti-inflammatory activity, attenuating the anxious behavior of abstinent animals and reducing neuroinflammation in AN and mHN; and the intensity of the anxiolytic and anti-inflammatory effect of α-tocopherol is dose-dependent. These results identify α-tocopherol as a potential therapeutic target supporting the fight against relapse during alcohol withdrawal.

Keywords: alcohol dependence; anxiety; chronic alcohol exposure; neuroinflammation; oxidative stress; withdrawal.

MeSH terms

  • Alcoholism* / complications
  • Animals
  • Anti-Anxiety Agents*
  • Anxiety / drug therapy
  • Diet
  • Ethanol
  • Male
  • Rats
  • Rats, Wistar
  • Substance Withdrawal Syndrome* / drug therapy
  • alpha-Tocopherol / pharmacology
  • alpha-Tocopherol / therapeutic use

Substances

  • Ethanol
  • alpha-Tocopherol
  • Anti-Anxiety Agents