Fenugreek, A Potent Hypoglycaemic Herb Can Cause Central Hypothyroidism Via Leptin - A Threat To Diabetes Phytotherapy

Exp Clin Endocrinol Diabetes. 2017 Jul;125(7):441-448. doi: 10.1055/s-0043-103458. Epub 2017 Apr 13.


Fenugreek (Trigonella foenum graecum), a medicinal herb with potent antihyperglycaemic and hypoglycaemic effects, is used to treat diabetes. This study is aimed to explore the interaction of fenugreek seed extract (FSE) and HPT (hypothalamic-pituitary-thyroid) axis in context of leptin secretion which have important role in normal and type-1 diabetic subjects. FSE (confirmed to contain trigonelline, diosgenin, 4 hydroxyisoleucine) was gavaged (0.25 gm/kg body weight/day) to normal and alloxan-induced type-1 diabetic rats for 4 weeks. Expression of hypothalamic prepro-TRH (Thyrotropin releasing hormone) mRNA, serum levels of TRH, TSH (Thyroid stimulating hormone), fT3, fT4, insulin, leptin, glucose; thyroperoxidase activity and growth of thyroid gland, food intake, adiposity index were also studied FSE significantly down regulated prepro-TRH mRNA expression; decreased serum TRH, TSH, fT3, fT4 levels, and regressed thyroid gland in FSE-fed normal and diabetic rats than those observed in normal diet-fed control and diabetic rats. FSE decreased (p<0.005-0.001) adiposity index and leptin secretion, increased food intake and body weight in all FSE-fed rats. FSE improved insulin secretion, decreased glucose level but impaired HPT axis in diabetic rats, indicating insulin-independent central hypothyroidism. Results suggested that the dominant signal to hypothalamus suppressing HPT axis is the fall in leptin level which i resulted from decreased adiposity index following FSE feeding. Fenugreek simultaneously having hypoglycaemic and hypothyroidal actions raises questions whether it can be safely used to treat diabetes and/or hyperthyroidism as was suggested by many workers.

MeSH terms

  • Animals
  • Diabetes Mellitus, Experimental* / blood
  • Diabetes Mellitus, Experimental* / drug therapy
  • Hypoglycemic Agents / adverse effects*
  • Hypothyroidism* / blood
  • Hypothyroidism* / chemically induced
  • Leptin / blood*
  • Phytotherapy / adverse effects*
  • Plant Preparations* / adverse effects
  • Plant Preparations* / pharmacology
  • Plants, Medicinal / adverse effects*
  • Rats
  • Rats, Wistar
  • Thyroid Hormones / blood
  • Trigonella / adverse effects*


  • Hypoglycemic Agents
  • Leptin
  • Plant Preparations
  • Thyroid Hormones