Protective effect of a polyherbal bioactive fraction in propylthiouracil-induced thyroid toxicity in ratsby modulation of the hypothalamic-pituitary-thyroid and hypothalamic-pituitary-adrenal axes

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Hypothyroidism is the most frequent toxic effect of a large variety of chemical compounds.

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The polyherbal bioactive fraction exhibited a pro-thyroid effect in hypothyroidic rats.

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The polyherbal fraction restored the propylthiouracil-depleted thyroid hormone levels significantly.

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The polyherbal fraction may act through multiple mechanisms to exhibit a pro-thyroid effect.

Hypothyroidism is the most frequent consequence of the interaction of a large variety of drugs, environmental pollutants and industrial chemicals with the thyroid gland. It is associated with diminished endocrine function which may lead to hyperlipidemia, diabetes, Alzheimer’s disease, weight gain, and other metabolic disorders. The present study evaluates the pro-thyroid activity of a bioactive fraction from a polyherbal teabag in rats with hypothyroidism induced by propylthiouracil. The teabag was formulated to stimulate synthesis and/or release of T4 and affectthe conversion of T4 to T3. Phytoconstituents of the polyherbal teabag are potent antioxidants that may be responsible for the pro-thyroid activity. The tea-extract (1000 mg) was found to contain 1076 μg of gallic acid and 1131 μg of rutin from HPTLC analysis. Rats received propylthiouracil (8 mg/kg) for the first 15days followed by the polyherbal tea-extract (500, 1000 and 1500 mg/kg), the standard drug levothyroxine (0.1 mg/kg), aerobic exercise, and a combination of tea-extract (1000 mg/kg) and aerobic exercise daily along with propylthiouracil for the next 30 days. Finally, rats received their respective treatments alone without propylthiouracil for 15 more days. Lipid profile and levels of glucose, insulin, T3, T4, TSH, cortisol, homocysteine, creatinine, uric acid, malondialdehyde, glucose-6 phosphatase, and endogenous antioxidants were determined. All treatments attenuated significantly the propylthiouracil-elevated TSH, homocysteine, creatinine, uric acid, glucose-6-phosphatase, insulin, and malondialdehyde levels, and restored favorably the propylthiouracil-altered lipid profile, T3, T4, and endogenous antioxidant levels. The polyherbal tea-extract (1000 and 1500 mg/kg) treatment and thecombination treatment of tea-extract (1000 mg/kg) with aerobic exercise displayed significant restoration of the suboptimalthyroid function. This may be due to a favorablemodulation ofthe hypothalamic-pituitary–thyroid and the hypothalamic–pituitary–adrenal axes.

Normal menstrual cycle steroid hormones variation does not affect the blood levels of total adiponectin and its multimer forms

Objective

Plasma total adiponectin reveals a sexual dimorphism indicating that gonadal steroids may be involved in its secretion and/or metabolism. However, results from previous reports are conflicting and data regarding the influence of ovarian steroids on adiponectin's multimer forms are scarce. The objective of the study was to assess if total adiponectin and its isoforms are affected by the changes of estradiol and progesterone during the normal menstrual cycle and the association of total adiponectin and its isoforms with the gonadal steroid levels.

Materials/methods

Quantitative determination of plasma adiponectin and its multimers was conducted in the three phases of an ovulatory cycle in 13 premenopausal women, in the follicular phase of 10 more premenopausal women, in 20 postmenopausal women and in 21 men. Moreover, serum levels of FSH, LH, prolactin, estradiol, progesterone, and testosterone, sex hormone binding globulin, glucose, and insulin were measured.

Results

The circulating levels of total adiponectin and its multimers were not affected by the normal variation of estradiol and progesterone across the ovulatory menstrual cycle. In the whole number of participants, the total adiponectin and high molecular weight adiponectin levels were significantly different between genders and associated positively with age and sex hormone binding globulin levels, and negatively with testosterone and progesterone levels and the waist/hip ratio. In the multiple logistic regression analysis, after adjustment for age, gender, and sex hormone binding globulin and progesterone levels, significant predictors of total adiponectin levels were the waist/hip ratio and testosterone levels, and of high molecular weight adiponectin the testosterone levels.

Conclusions

Normal menstrual cycle ovarian steroids are not involved directly in the regulation of secretion and/or metabolism of total adiponectin and its multimers. Testosterone seems to be responsible for the adiponectin's sexual dimorphism.

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Adiponectin and its multimers were assessed in the three-step hormonal model of normal menstrual cycle.

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Estrogens may not be involved directly in the regulation of adiponectin's secretion and/or metabolism.

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Androgens appear to be responsible for the sexual dimorphism of adiponectin.

The value of neck circumference (NC) as a predictor of non-alcoholic fatty liver disease (NAFLD)

Aims

To analyze the correlation between neck circumference (NC) and non-alcoholic fatty liver disease (NAFLD) and compare the predictive value of NC for NAFLD with that of other simple anthropometric measures and other biochemical profiles.

Methods

2761 subjects, undergoing a medical check-up at the Changhai Hospital between October 01, 2012 and November 30, 2012, were recruited to the study. NC, other simple anthropometric measures, and biochemical profiles were analyzed.

Results

NC in NAFLD subjects with or without elevated ALT were 38.94 ± 2.62 cm and 37.21 ± 3.06 cm respectively, which was significantly higher than that in subjects with other metabolic disorders (NC: 35.33 ± 3.03 cm) and in normal controls (NC: 32.60 ± 2.37) (both P < 0.001). NC in women with NAFLD increased by 1 cm and fasting insulin (FINS) and homeostasis model assessment-insulin resistance (HOMA-IR) increased by 1.87 mIU/L and 1.43, respectively. Compared with other anthropometric measures, neck circumference-height ratio (NHtR) had a significant impact both on the incidence of NAFLD. After adjustment for sex, abdominal obesity and other influencing factors, the incidence of NAFLD still tended to positively correlate with NC. Optimal cut-off points of NC and NHtR for predicting NAFLD in males were 37.25 cm and 0.224, respectively, and such points in females were 32.90 cm and 0.208, respectively.

Conclusion

NC was wider in NAFLD patients than in healthy subjects and other metabolic disorder sufferers. NC and NHtR could be used as simple predictive tools for NAFLD.