Magnolol decreases body temperature by reducing 5-hydroxytryptamine release in the rat hypothalamus

Clin Exp Pharmacol Physiol. 1998 Oct;25(10):813-7. doi: 10.1111/j.1440-1681.1998.tb02158.x.


1. The effects of magnolol, isolated and purified from the cortex of Magnolia officinalis Rehd. et Wils, on thermoregulation and hypothalamic release of 5-hydroxytryptamine (5-HT) by in vivo microdialysis were assessed in normothermic rats and in febrile rats treated with interleukin-1 beta. 2. Intraperitoneal administration of magnolol (25-100 mg/kg) produced a decrease in colon temperature, an increase in foot skin temperature, a decrease in metabolic rate and a decrease in the endogenous release of 5-HT in the rat hypothalamus. 3. Depletion of rat brain 5-HT, produced by intracerebroventricular pretreatment with 5,7-dihydroxytryptamine, attenuated the magnolol-induced hypothermia, cutaneous vasodilation and decreased metabolism. 4. Intracerebroventricular administration of (+/-)-2,5-dimethoxy-4-iodoamphetamine (a 5-HT2 receptor agonist; 5-10 micrograms/5 microL) increased basal colon temperature and reversed the magnolol-induced hypothermia. 5. The increases in both colon temperature and hypothalamic 5-HT release produced by interleukin-1 beta injection were attenuated by treatment with magnolol. 6. The data suggest that magnolol decreases body temperature (due to increased heat loss and decreased heat production) by reducing 5-HT release in rat hypothalamus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biphenyl Compounds / isolation & purification
  • Biphenyl Compounds / pharmacology*
  • Body Temperature Regulation / drug effects*
  • Central Nervous System Depressants / pharmacology*
  • Colon
  • Down-Regulation
  • Hypothalamus / drug effects*
  • Hypothalamus / physiology
  • Interleukin-1 / pharmacology
  • Lignans*
  • Male
  • Plants, Medicinal / chemistry
  • Rats
  • Rats, Sprague-Dawley
  • Serotonin / analysis
  • Serotonin / metabolism*
  • Serotonin Antagonists / pharmacology
  • Skin


  • Biphenyl Compounds
  • Central Nervous System Depressants
  • Interleukin-1
  • Lignans
  • Serotonin Antagonists
  • magnolol
  • Serotonin