Goat's Rue, Metformin and a Botanical Approach to Type 2 Diabetes
Type 2 diabetes and the botanical consensus statement Dr Luke Iggulden wrote in 2016, starting with goat's rue (Galega officinalis), whose guanidine alkaloid galegine led chemists to metformin.
The episode opens with the disease itself: insulin resistance in muscle, liver and fat, the TCF7L2 gene, and how fasting blood glucose, the oral glucose tolerance test and HbA1c are read, including why HbA1c alone can mislead in anaemia or kidney disease. It then runs through the main drug classes, from GLP-1 agonists such as semaglutide and the sulfonylureas to pioglitazone, the alpha-glucosidase blockers and metformin.
Five core botanicals follow, each with its chemistry, ethanol strength for extraction and safety notes: goat's rue, Gymnema sylvestre and its gymnemic acids, fenugreek (Trigonella foenum-graecum) with 4-hydroxyisoleucine and seed mucilage, cinnamon (Cinnamomum verum) at 70% ethanol, and Phyllanthus amarus. Support for complications covers evening primrose oil for neuropathy, maitake and other beta-glucan mushrooms for immunity, bilberry (Vaccinium myrtillus) for retinopathy, milk thistle (Silybum marianum) for the liver, and ginger for circulation. It closes on the statement's case for herbalists and medical practitioners working together, with any change to prescribed medicine made jointly.
In this episode: (00:00) Metformin and a garden weed; (01:45) What happens in type 2 diabetes; (07:12) Family history and the TCF7L2 gene; (09:25) FBG, OGTT and HbA1c; (14:13) GLP-1 agonists, sulfonylureas and pioglitazone; (16:34) Metformin, guanidine and goat's rue; (19:01) A low GI diet; (20:27) Antioxidants and oxidative stress; (23:50) Prebiotic fibre and the gut; (24:39) Meditation and forest bathing; (26:42) Cold percolation; (29:29) Dry extracts and coated tablets; (32:41) Goat's rue (Galega officinalis); (34:45) Gymnema sylvestre; (37:27) Fenugreek; (39:15) Cinnamon; (40:29) Phyllanthus amarus; (42:32) Neuropathy and evening primrose oil; (43:19) Immunity and medicinal mushrooms; (44:19) Retinopathy and bilberry; (45:01) The liver and milk thistle; (45:54) Circulation and the kidneys; (46:59) Conflict of interest and integrative care; (48:57) Herbs and drugs in combination; (51:36) Closing thought.
About this episode: The Herbarium Hour is a third-party production based on the Institute's published papers. It is not produced in-house, and the hosts are not Institute staff. Where they get a technical detail wrong, the correction is listed here.
Corrections. The podcast hosts misinterpreted the following from our papers:
(00:28) The hosts said: Metformin is essentially an isolated compound from goat's rue. Correct: Metformin is a synthetic biguanide; it was developed from galegine, a guanidine alkaloid in goat's rue, and is not found in the plant itself.
(02:01) The hosts said: The defining characteristic of type 2 diabetes is pancreatic beta cell insulin insensitivity. Correct: Type 2 diabetes is defined by insulin resistance in muscle, liver and fat cells together with a progressive decline in beta cell insulin secretion.
Nothing in this episode is a prescription or a dose. If you want to use a herb, consult a degree-qualified herbalist with competencies and adequate training in pharmacognosy.
Dr Luke Iggulden, Chief Scientific Officer, wrote the 2016 botanical consensus statement the episode is based on and chose it for the show. Jesse Kirby, Head of Community Outreach, wrote the title, show notes, chapters and corrections from the episode transcript and scheduled the release.
The Herbarium Hour, from the Australian Institute of Pharmacognosy, Cardwell, Queensland.