Endocrine Abstracts

Background: Metformin is one of the first line drugs used to treat type 2 diabetes mellitus, even though there are still many gaps on how exactly metformin works. This is due to many years of research using various concentrations of metformin and also, not considering the conditional effect that glucose can have in its action.

Objectives: Study the effect of different concentrations of metformin and glucose in cell culture.

Methods: a commercial cell line (hTERT RPE-1) was cultured under two different conditions of glucose (high-4.5 g/l or low-1 g/l) and under different concentrations of metformin.

Results: the concentration of glucose affects directly to cell proliferation, being higher in the cells exposed to high glucose. Considering metformin concentration, it could be observed that under suprapharmacological conditions (1 M) cells showed a complete cell dead under both conditions of glucose at 12 h; however, when the suprapharmacological concentrations were lower (10 mM), the cell dead could only be seen at 48 h and under the low glucose condition. When pharmacological concentrations (50 μM) were used, even though there was a decrease in cell viability, cells didn’t show major signs of dead after 15 days of growth. This same tendency was observed when analysing cell culture supernatant, where glucose levels of 10 mM treatment were almost none after 48 h in the low glucose condition, while for the 50 μM treatment, the levels were very close to control cell culture.

Conclusions: it is important to consider glucose concentration as well as metformin concentration when analysing the effect of this drug.