Exp Clin Endocrinol Diabetes 2017; 125(07): 441-448
DOI: 10.1055/s-0043-103458
Article
© Georg Thieme Verlag KG Stuttgart · New York

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

Jayjeet Majumdar
1   Department of Zoology, City College, 102/1 Raja Rammohan Sarani, Kolkata, Affiliated to University of Calcutta, West Bengal, India
,
Pratip Chakraborty
1   Department of Zoology, City College, 102/1 Raja Rammohan Sarani, Kolkata, Affiliated to University of Calcutta, West Bengal, India
,
Analava Mitra
2   School of Medical Science & Technology, Indian Institute of Technology, Kharagpur, Kharagpur, West Bengal, India
,
Nirmal kumar Sarkar
3   Department of Biological Sciences, Presidency University, Kolkata, West Bengal, India
,
Supriti Sarkar
1   Department of Zoology, City College, 102/1 Raja Rammohan Sarani, Kolkata, Affiliated to University of Calcutta, West Bengal, India
› Author Affiliations
Further Information

Publication History

received 16 November 2016
revised 01 February 2017

accepted 10 February 2017

Publication Date:
13 April 2017 (online)

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Abstract

Introduction

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.

Materials and Methods

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

Results

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.

Conclusion

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.