Protective effects of curcumin against thyroid hormone imbalance after gas explosion-induced traumatic brain injury via activation of the hypothalamic-pituitary-thyroid axis in male rats

Environ Sci Pollut Res Int. 2022 Oct;29(49):74619-74631. doi: 10.1007/s11356-022-20943-2. Epub 2022 May 31.

Abstract

Gas explosion (GE)-induced traumatic brain injury (TBI) can affect thyroid hormone (TH) homeostasis in miners. This study evaluated the effects of hepatic transthyretin and hypothalamic-pituitary-thyroid (HPT) axis on thyroids and explored the protective effect and mechanism of curcumin on GE-induced TBI. Thirty rats were randomly divided into three groups (10 per group): first group (control group)-rats received GE treatment once; second group (GE group)-rats received GE treatment (200 m from the source of the explosion once); third group (GE + Cur group)-rats received curcumin (Cur) by lavage at a dose of 100 mg/kg/day once every other day for 7 days after receiving GE. After GE, the pathological changes were analyzed by hemotoxylin and eosin staining, and the levels of serum reactive oxygen species (ROS), urine iodine (UI), THs, nuclear factor-kappa B (NF-κB), superoxide dismutase (SOD), glutathione peroxidase (Gpx), and malondialdehyde (MDA) were analyzed using ELISA. Expression of proteins in the HPT axis of rats was examined by immunohistochemistry and Western blotting. We found that GE could induce pathologic changes in rat thyroid and liver. Serum levels of THs, NF-κB and serum redox state became unbalanced in rats after GE. GE could inhibit the biosynthesis and biotransformation of THs by affecting key HPT axis proteins. Additionally, GE reduced the level of hepatic transthyretin. Serum THs levels and thyroid sections were almost recovered to normal after curcumin treatment. The aforementioned key HPT axis proteins in the curcumin group showed opposite expression trends. In summary, GE affected THs balance while curcumin can protect against these injury effects by affecting TH biosynthesis, biotransformation, and transport, and inducing oxidative stress and inflammatory responses.

Keywords: Curcumin; Gas explosion; HPT axis; Hepatic transthyretin; Thyroid hormone imbalance; Traumatic brain injury.

MeSH terms

  • Animals
  • Brain Injuries, Traumatic*
  • Curcumin* / pharmacology
  • Eosine Yellowish-(YS)
  • Explosions
  • Glutathione Peroxidase / metabolism
  • Hematoxylin / pharmacology
  • Iodine*
  • Male
  • Malondialdehyde / metabolism
  • NF-kappa B / metabolism
  • Oxidative Stress
  • Prealbumin / metabolism
  • Prealbumin / pharmacology
  • Rats
  • Reactive Oxygen Species / metabolism
  • Superoxide Dismutase / metabolism
  • Thyroid Gland / metabolism
  • Thyroid Hormones / metabolism

Substances

  • NF-kappa B
  • Prealbumin
  • Reactive Oxygen Species
  • Thyroid Hormones
  • Malondialdehyde
  • Iodine
  • Glutathione Peroxidase
  • Superoxide Dismutase
  • Curcumin
  • Eosine Yellowish-(YS)
  • Hematoxylin