What is Berberine?
Berberine is an isoquinoline alkaloid, one of the numerous classes of natural compounds purported to have medicinal properties, present also in Coptis sp., Berberis sp. and Phellodendri Chinensis Cortex. It has been used in traditional Chinese and Ayurvedic medicine for more than 1,000 years to treat a range of afflictions [1, 2, 3].
What does Berberine do?
Berberine has multiple pharmacological effects. It has been discussed as a potential treatment for numerous diseases, including diabetes, cardiovascular disease and neurological conditions.
It has greatly lowered fasting blood glucose and haemoglobin A1C, inflammatory cytokines and markers of oxidative stress. It has increased insulin secretion and improved insulin resistance, it has also protected against diabetes-related complications such as hepatic damage, cardiovascular disorders, nephropathy and neuropathy [4].
Berberine also shows neuroprotective effects: it can protect the neuron due to anti-apoptotic, antioxidative and anti-inflammatory action, through various signalling pathways, and also provide neuroprotection [5, 6].
Even more impressively, berberine is highly active against bacteria, viruses, fungi, protozoans, helminths and chlamydia. In addition to being anti-inflammatory, clinically it has been proven effective for use against intestinal diarrhoea, parasitic infection and afflictions of the eye by trachoma. [7]
Besides, berberine shows potential in cancer treatment. It suppresses the growth of different kinds of cancer cells and the invasion and metastasis. At the same time, berberine may enhance both the efficacy and safety of the necessary chemo-radiotherapies [2, 8].
What is the Thyroid?
The thyroid gland is part of the endocrine system, which regulates the body’s metabolism by producing hormones and secreting them from the thyroid gland in the front of the neck. Squeezed tight like a butterfly, this small flap of muscle and tissue is a necessary organ for the body’s overall well-being [9, 10].
The thyroid gland secretes two main hormones, thyroxine (T4) and triiodothyronine (T3), which move in blood to tissues throughout the body, where they regulate physiological processes [11, 10].
What is the Function of the Thyroid?
Thyroid hormones T4 and T3 regulate metabolic and energy-producing processes in the body, as well as the functions of organs and tissues. They regulate lipid, carbohydrate and protein metabolism, cardiovascular, renal and brain functions [11].
Thyroid-stimulating hormone (TSH), from the pituitary gland, stimulates thyroid secretion of T4 and T3. Feedback occurs when these hormones are adequate, which causes the pituitary to reduce TSH production [12].
Alongside its metabolic role, the thyroid promotes growth and development: thyroid hormones are, for instance, vital in brain development during infancy and childhood [9].
Can Berberine influence Thyroid function?
Though berberine is a natural alkaloid used in many medicinal plants, its impact on thyroid function, specifically, is currently uncertain. But a closer look at the science explains how berberine may indirectly affect the thyroid gland in beneficial ways.
In obese human subjects, after 12 weeks of berberine treatment, no substantial changes in the levels of cortisol (stress), calcitriol, ACTH, TSH, FT4 (thyroid hormone) and SHBG were observed [13]. In humans, it appears, that berberine may have no direct effect on levels of thyroid hormones.
On the other hand, berberine was found to exhibit thyroid-stimulating as well as suppressing activities in a rat model, depending on its drug dosage – in particular, a 50 mg/kg dose of berberine was observed to exert thyroid-stimulating properties [14].
Concerning thyroid cancer, berberine exerts an antiproliferation effect on thyroid carcinoma cells in a time- and dose-dependent manner by inducing mitochondrial apoptosis, G0/G1 cell cycle arrest and cell migration suppression [15, 16].
Conclusion
To conclude, even though berberine does not appear to act on levels of thyroid hormone itself, it might affect thyroid function indirectly – and maybe even in thyroid cancer. More research is necessary before we can fully explore the effects of berberine on thyroid function.