Green tea and metformin.

[Guest guest]

Green tea, like the anti-diabetic drug metformin, slows absorption of sugars

and starches. That means more of it gets into the colon/caecum where it

increases the acidity of the environment as it undergoes microbial

fermentation (as one of the research papers I cited showed). This can result

in gassyness and some looseness of stool.

 

These are the most common side effects of Metformin, a drug which also

reduces glucose absorption from the small intestine, but increases periferal

insulin sensitivity at the same time.

 

Such side effects would normally (I would guess?) be ascribed to spleen qi

weakness. Could they correctly be treated as such? In other words

could/should such side effects be compensated for in a herbal formula

somehow??

 

Couple of papers below. I am not diabetic BTW, just have some insulin

resistance (bit of phlegm/damp, some spleen qi deficiency and qi stagnation/

heart heat at stressy times). Thinking of trying metformin for a while from

the doc. as well as herbal therapy, which is going well, but progress is

slow (long way to go).

 

Jackie

 

 

1: Naunyn Schmiedebergs Arch Pharmacol. 2000 Jan;361(1):85-91. Related

Articles, Links

 

 

Effects of metformin on intestinal 5-hydroxytryptamine (5-HT) release and on

5-HT3 receptors.

 

Cubeddu LX, Bonisch H, Gothert M, Molderings G, Racke K, Ramadori G, Miller

KJ, Schworer H.

 

Department of Pharmacology, School of Pharmacy, Central University of

Venezuela.

 

Nearly 30% of patients treated with metformin experience gastrointestinal

side effects. Since release of 5-hydroxytryptamine (5-HT) from the intestine

is associated with nausea, vomiting, and diarrhea, we examined whether

metformin induces 5-HT release from the intestinal mucosa. In 40% of tissue

biopsy specimens of human duodenal mucosa, metformin (1, 10, and 30 microM)

caused an increase in 5-HT outflow by 35, 70, and 98%, respectively. Peak

increases in 5-HT outflow were observed after 10-15 min exposure to

metformin, returning to baseline levels after 25 min. Tetrodotoxin (1

microM) reduced by about 50% the metformin-evoked increase in 5-HT outflow

(P<0.05). Metformin-evoked release was not affected by scopolamine +

hexamethonium, propranolol, the 5-HT3 receptor antagonist dolasetron,

naloxone, or the NK1 receptor antagonist L703606. In the presence of

tetrodotoxin (1 microM), somatostatin (1 microM) further reduced

metformin-induced 5-HT release by 15-20%. In view of the 5-HT releasing

effects of selective 5-HT3 receptor agonists to which metformin

(N-N-dimethylbiguanide) is structurally related, we investigated whether

metformin directly interacts with 5-HT3 receptors. Receptor binding

(inhibition of [3H]-GR65630 binding) and agonist effects (stimulation of

[14C]-guanidinium influx) at 5-HT3 receptors were studied in murine

neuroblastoma N1E-115 cells, which express functional 5-HT3 receptors.

Metformin up to 0.3 mM failed to inhibit [3H]-GR65630 binding and to modify

displacement of [3H]-GR65630 binding induced by 5-HT. 5-HT (3 microM)

stimulated the influx of [14C]-guanidinium in intact N1E-115 cells.

Metformin up to 1 mM failed to modify basal influx, 5-HT-induced influx, and

5-HT+ substance P-induced influx of [14C]-guanidinium. Our results indicate

that metformin induces 5-HT3 receptor-independent release of 5-HT from human

duodenal mucosa via neuronal and non-neuronal mechanisms. Part of the

gastrointestinal side effects observed during treatment with metformin

could, thus, be produced by the release of 5-HT and other neurotransmitter

substances within the duodenal mucosa.

 

PMID: 10651152 [PubMed - indexed for MEDLINE]

 

1: Diabet Med. 1999 Aug;16(8):670-4. Related Articles, Links

 

 

Gastrointestinal symptoms in Chinese patients with Type 2 diabetes mellitus.

 

Ko GT, Chan WB, Chan JC, Tsang LW, Cockram CS.

 

Department of Medicine and Therapeutics, Chinese University of Hong Kong,

Prince of Wales Hospital, Shatin, New Territories. gtc_ko

 

AIMS: To examine and compare gastrointestinal (GI) symptoms in Hong Kong

Chinese Type 2 diabetic outpatients and non-diabetic control subjects.

METHODS: A total of 149 Chinese Type 2 diabetic patients (66 men and 83

women, age (mean +/- SD) 46.8+/-11.1 years) newly referred to the diabetes

clinic of the Prince of Wales Hospital, Hong Kong were examined. Sixty-five

age and sex-matched non-diabetic subjects were recruited from the community

as controls (22 men and 43 women, age (mean +/- SD) 46.5+/-6.6 years, P =

0.820). All patients were interviewed regarding GI symptoms over the past

year, using a questionnaire that covered 14 items. A scoring system from 0

to 4 was used to grade severity. RESULTS: Diabetic patients had higher blood

pressure, fasting plasma glucose and glycated haemoglobin and were more

often smokers than control subjects. Of the 149 diabetic subjects, 105

(70.5+/-45.8%) had GI symptoms while only 20 (30.8%) of the 65 control

subjects had GI symptoms (P<0.001). The respective percentages of upper and

lower GI symptoms in diabetic and normal subjects were 44.3% vs. 24.6% (P =

0.006) and 54.4% vs. 13.9% (P<0.001). The three commonest GI symptoms in

diabetic patients were diarrhoea (34.9%), constipation (27.5%) and

epigastric fullness (16.8%). After adjustment for age, sex, duration of

diagnosed diabetes and smoking, patients with or without metformin had

similar percentages or scores for GI symptoms. On multivariate analysis

using age, body mass index, fasting plasma glucose, glycated haemoglobin,

duration of diagnosed diabetes and presence of peripheral neuropathy as

independent variables, duration of diabetes was the only independent

parameter associated with total score for GI symptoms (beta = 0.116, P =

0.003), for upper GI symptoms (beta = 0.073, P = 0.005) and for lower GI

symptom (beta = 0.043, P = 0.020). CONCLUSIONS: Up to 70% of the Chinese

Type 2 diabetic outpatients have GI symptoms, which is a much higher rate

than in non-diabetic control subjects. Duration of diabetes is the most

important factor associated with the presence of such GI symptoms.

 

PMID: 10477212 [PubMed - indexed for MEDLINE]