Metformin (hydrochloride) is a first-line drug for the treatment of type 2 diabetes and there is increasing evidence of a potential efficacy of this agent as an anti-cancer drug.

Metformin inhibits proliferation of ESCs in a concentration-dependent manner. The IC₅₀ is 2.45 mM for A-ESCs and 7.87 mM for N-ESCs. Metformin shows pronounced effects on activation of AMPK signaling in A-ESCs from secretory phase than in cells from proliferative phase^[3]. Metformin (0-500 μM) decreases glycogen synthesis in a dose-dependent manner with an IC₅₀ value of 196.5 μM in cultured rat hepatocytes^[4]. Metformin shows cell viability and cytotoxic effects on PC-3 cells with IC₅₀ of 5 mM^[5].

Metformin (100 mg/kg, p.o.) alone, and metformin (25, 50, 100 mg/kg) with isoproterenol groups attenuates myocyte necrosis through histopathological analysis^[1]. Metformin (> 900 mg/kg/day, p.o.) results in moribundity/mortality and clinical signs of toxicity in Crl:CD(SD) rats^[2].

• [1]. Soraya H, et al. Acute treatment with metformin improves cardiac function following isoproterenol induced myocardial infarction in rats. Pharmacol Rep. 2012;64(6):1476-84.

  [2]. Quaile MP, et al. Toxicity and toxicokinetics of metformin in rats. Toxicol Appl Pharmacol. 2010 Mar 15;243(3):340-7.

  [3]. Xue J, et al. Metformin inhibits growth of eutopic stromal cells from adenomyotic endometrium via AMPK activation and subsequent inhibition of AKT phosphorylation: a possible role in the treatment of adenomyosis. Reproduction. 2013 Aug 21;146(4):397-406.

  [4]. Otto M, et al. Metformin inhibits glycogen synthesis and gluconeogenesis in cultured rat hepatocytes. Diabetes Obes Metab. 2003 May;5(3):189-94.

  [5]. Avci CB, et al. Therapeutic potential of an anti-diabetic drug, metformin: alteration of miRNA expression in prostate cancer cells. Asian Pac J Cancer Prev. 2013;14(2):765-8.

  [6]. Nie L, et al. The Landscape of Histone Modifications in a High-Fat Diet-Induced Obese (DIO) Mouse Model. Mol Cell Proteomics. 2017 Jul;16(7):1324-1334.

  [7]. Zhang D, et al. Metformin ameliorates BSCB disruption by inhibiting neutrophil infiltration and MMP-9 expression but not direct TJ proteins expression regulation. J Cell Mol Med. 2017 Jul 12.

Metformin is dissolved in double-distilled water at a stock concentration of 10 mM and stored at 4°C. 

ESCs are plated in 96-well plates at a concentration of 1×10³cells/well. After attachment, cells are treated with different doses of metformin/compound C for 0 min, 15 min, 1 h, and 24 h. MTT assays are performed as described previously. In brief, MTT (5 mg/mL) is added to the 96-well plates at a volume of 10 μL/well, and the plates are incubated for 4 h. The MTT reaction is terminated by removal of the culture medium containing MTT, and 100 μL DMSO per well are added and incubated at RT on a shaker for 10 min to ensure that the crystals had dissolved sufficiently. Absorbance values are measured at 595 nm. Cell proliferation (percentage of control) is calculated as follows: absorbance (experimental group)/absorbance (control group). Cell proliferation inhibition (percentage of control) is calculated as follows: 100%−cell proliferation (percentage of control). Each experiment is performed in duplicate and repeated six times to assess result consistency. MCE has not independently confirmed the accuracy of these methods. They are for reference only.

Metformin (hydrochloride) is dissolved in physiological saline.

The animals are randomized into six groups consisting of six rats each. Rats in group 1 (control) receives a subcutaneous injection of physiological saline (0.5 mL) and are left untreated for the entire experimental period. Rats in group 2 receives an oral administration of metformin (100 mg/kg; twice daily) for 2 days and are subcutaneously injected with saline at an interval of 24 h for 2 consecutive days. Rats in group 3 (MI control) receives an oral administration of saline (twice daily) for 2 days and are sc injected with isoproterenol (100 mg/kg) daily for 2 consecutive days at an interval of 24 h. Rats in groups 4 to 6 are treated with metformin at 25, 50, and 100 mg/kg. Metformin is dissolved in saline and is gavaged at a volume of 0.25-0.5 mL twice a day at an interval of 12 h, started immediately before isoproterenol injection. MCE has not independently confirmed the accuracy of these methods. They are for reference only.

• [1]. Soraya H, et al. Acute treatment with metformin improves cardiac function following isoproterenol induced myocardial infarction in rats. Pharmacol Rep. 2012;64(6):1476-84.

  [2]. Quaile MP, et al. Toxicity and toxicokinetics of metformin in rats. Toxicol Appl Pharmacol. 2010 Mar 15;243(3):340-7.

  [3]. Xue J, et al. Metformin inhibits growth of eutopic stromal cells from adenomyotic endometrium via AMPK activation and subsequent inhibition of AKT phosphorylation: a possible role in the treatment of adenomyosis. Reproduction. 2013 Aug 21;146(4):397-406.

  [4]. Otto M, et al. Metformin inhibits glycogen synthesis and gluconeogenesis in cultured rat hepatocytes. Diabetes Obes Metab. 2003 May;5(3):189-94.

  [5]. Avci CB, et al. Therapeutic potential of an anti-diabetic drug, metformin: alteration of miRNA expression in prostate cancer cells. Asian Pac J Cancer Prev. 2013;14(2):765-8.

  [6]. Nie L, et al. The Landscape of Histone Modifications in a High-Fat Diet-Induced Obese (DIO) Mouse Model. Mol Cell Proteomics. 2017 Jul;16(7):1324-1334.

  [7]. Zhang D, et al. Metformin ameliorates BSCB disruption by inhibiting neutrophil infiltration and MMP-9 expression but not direct TJ proteins expression regulation. J Cell Mol Med. 2017 Jul 12.

165.62

C₄H₁₂ClN₅

1115-70-4

Room temperature in continental US; may vary elsewhere

H₂O: ≥ 32 mg/mL; DMSO: ≥ 1.7 mg/mL

Metformin hydrochloride is prepared in 0.5% methylcellulose^[6].
Metformin hydrochloride is diluted with normal saline, to achieve a final metformin concentration of 20 mg/mL^[7].

* "<1 mg/ml"="" means="" slightly="" soluble="" or="" insoluble.="" "≥"="" means="" soluble,="" but="" saturation="">

• [1]. Soraya H, et al. Acute treatment with metformin improves cardiac function following isoproterenol induced myocardial infarction in rats. Pharmacol Rep. 2012;64(6):1476-84.

  [2]. Quaile MP, et al. Toxicity and toxicokinetics of metformin in rats. Toxicol Appl Pharmacol. 2010 Mar 15;243(3):340-7.

  [3]. Xue J, et al. Metformin inhibits growth of eutopic stromal cells from adenomyotic endometrium via AMPK activation and subsequent inhibition of AKT phosphorylation: a possible role in the treatment of adenomyosis. Reproduction. 2013 Aug 21;146(4):397-406.

  [4]. Otto M, et al. Metformin inhibits glycogen synthesis and gluconeogenesis in cultured rat hepatocytes. Diabetes Obes Metab. 2003 May;5(3):189-94.

  [5]. Avci CB, et al. Therapeutic potential of an anti-diabetic drug, metformin: alteration of miRNA expression in prostate cancer cells. Asian Pac J Cancer Prev. 2013;14(2):765-8.

  [6]. Nie L, et al. The Landscape of Histone Modifications in a High-Fat Diet-Induced Obese (DIO) Mouse Model. Mol Cell Proteomics. 2017 Jul;16(7):1324-1334.

  [7]. Zhang D, et al. Metformin ameliorates BSCB disruption by inhibiting neutrophil infiltration and MMP-9 expression but not direct TJ proteins expression regulation. J Cell Mol Med. 2017 Jul 12.