印度含氰植物性食物的致甲状腺肿成分及其体外抗甲状腺活性。

Goitrogenic content of Indian cyanogenic plant foods & their in vitro anti-thyroidal activity.

作者信息

Chandra Amar K, Mukhopadhyay Sanjukta, Lahari Dishari, Tripathy Smritiratan

机构信息

Endocrinology & Reproductive Physiology Laboratory, Department of Physiology, University College of Science & Technology, University of Calcutta, Kolkata, India.

出版信息

Indian J Med Res. 2004 May;119(5):180-5.

PMID:15218979

Abstract

BACKGROUND & OBJECTIVES: Consumption of cyanogenic foods has been considered as one of the etiological factors in certain instances for the persistence of endemic goitre. The present study was undertaken to study the cyanogenic glucosides, glucosinolates and thiocyanate content in edible portion of certain selected plant foods of Indian origin. Further in vitro anti-thyroidal activity using raw, boiled and cooked extracts of these plants with and without excess iodide was also studied.

METHODS

Cyanogenic plant foods generally vegetables were collected from different areas of West Bengal and Tripura. Cassava was obtained from Meghalaya and Kerala and their cyanogenic glucosides, glucosinolates and thiocyanate were estimated. Thyroid peroxidase activity (TPO) of human thyroid was assayed from microsomal fraction following I3- from iodide. The anti-TPO activities of the plants were assayed after adding raw, boiled and cooked extracts in the assay medium with and without extra iodide. Relative antithyroidal potency of the plant extracts was also evaluated in terms of the concentration (IC50) necessary to produce 50 per cent inhibition of TPO activity. PTU equivalence of the plant foods was also determined.

RESULTS

Cabbage and cauliflower were rich in glucosinolates, bamboo shoot and cassava were rich in cyanogenic glucosides, mustard, turnip and radish were relatively rich in thiocyanate however all the constituents were present in each plant. Boiled extracts showed maximum inhibition of TPO activity followed by cooked and raw extracts. Excess iodide was found relatively effective for raw extract but less effective for boiled and cooked extracts in reversing anti-TPO activity. Inhibition constant (IC50) was found highest with bamboo shoot and least with cabbage.

INTERPRETATION & CONCLUSION: Raw, boiled and cooked extracts of the plants showed anti-thyroidal activity in vitro. Excess iodide reversed the anti-TPO activity to same extent but could not neutralise it.

摘要

背景与目的

在某些情况下，食用含氰食物被认为是地方性甲状腺肿持续存在的病因之一。本研究旨在研究某些印度原产的特定植物性食物可食用部分中的氰苷、硫代葡萄糖苷和硫氰酸盐含量。此外，还研究了这些植物的生、煮和熟提取物在有无过量碘化物情况下的体外抗甲状腺活性。

方法

从西孟加拉邦和特里普拉邦的不同地区收集含氰植物性食物，一般为蔬菜。木薯取自梅加拉亚邦和喀拉拉邦，并对其氰苷、硫代葡萄糖苷和硫氰酸盐进行了测定。从微粒体部分用碘化物中的I3-测定人甲状腺的甲状腺过氧化物酶活性（TPO）。在测定培养基中加入生、煮和熟提取物，有无额外碘化物的情况下，测定植物的抗TPO活性。还根据产生50%TPO活性抑制所需的浓度（IC50）评估植物提取物的相对抗甲状腺效力。还测定了植物性食物的丙硫氧嘧啶等效性。

结果

卷心菜和花椰菜富含硫代葡萄糖苷，竹笋和木薯富含氰苷，芥菜、芜菁和萝卜相对富含硫氰酸盐，然而每种植物中都含有所有成分。煮提取物对TPO活性的抑制作用最大，其次是熟提取物和生提取物。发现过量碘化物对生提取物逆转抗TPO活性相对有效，但对煮提取物和熟提取物效果较差。竹笋的抑制常数（IC50）最高，卷心菜最低。