Parmar H S, Panda S, Jatwa R, Kar A
School of Life Sciences, DA University, Indore, India.
Pharmazie. 2006 Sep;61(9):793-5.
Terminalia arjuna bark extract is believed to exhibit cardio-protective effects. In the present study we investigated the possible involvement of thyroid hormones in the amelioration of cardiac and hepatic lipid peroxidation (LPO) by a bark extract of the plant in albino rats. While L-thyroxine (L-T4) treatment increased the level of thyroid hormones, heart/body weight ratio as well as cardiac and hepatic lipid peroxidation, simultaneous administration of 21.42 and 42.84 mg/kg of the plant extract decreased the level of thyroid hormones and also the cardiac LPO, suggesting the possible mediation of the drug action through an inhibition in thyroid function. These effects were comparable to a standard antithyroid drug, propyl thiouracil (PTU). When the drug was administered to euthyroid animals, serum concentrations of thyroid hormones were decreased, whereas the hepatic LPO increased indicating a drug induced toxicity in euthyroid subjects. Although a suboptimal dose of the drug was found to be non-toxic to the liver, it appeared to be of no use, as it could neither affect the thyroid functions nor the cardiac lipid peroxidation. Since in euthyroid animals, thyroid hormones were decreased and hepatic LPO was increased, it is suggested that high amounts of this plant extract should not be consumed, as hepatotoxicity as well as hypothyroidism may be caused.
诃子树皮提取物被认为具有心脏保护作用。在本研究中，我们调查了甲状腺激素是否可能参与了该植物树皮提取物对白化大鼠心脏和肝脏脂质过氧化（LPO）的改善作用。虽然L-甲状腺素（L-T4）治疗会增加甲状腺激素水平、心脏/体重比以及心脏和肝脏脂质过氧化，但同时给予21.42和42.84mg/kg的植物提取物会降低甲状腺激素水平以及心脏LPO，这表明药物作用可能是通过抑制甲状腺功能来介导的。这些作用与标准抗甲状腺药物丙硫氧嘧啶（PTU）相当。当将该药物给予甲状腺功能正常的动物时，甲状腺激素的血清浓度降低，而肝脏LPO增加，表明该药物在甲状腺功能正常的受试者中会引起药物诱导的毒性。虽然发现次优剂量的该药物对肝脏无毒，但它似乎没有作用，因为它既不能影响甲状腺功能也不能影响心脏脂质过氧化。由于在甲状腺功能正常的动物中，甲状腺激素降低而肝脏LPO增加，因此建议不应大量食用这种植物提取物，因为可能会导致肝毒性以及甲状腺功能减退。
