Table 1.

Effect of metformin administration on serum components and immune cell profiles

ControlMetformin
Blood (serum)n = 6n = 6
Glucose, mg/dL103.8 ± 14.3107.3 ± 10.0
Cholesterol, mg/dL99.8 ± 9.482.2 ± 9.0
Triglycerides, mg/dL74.0 ± 9.280.3 ± 9.8
Sodium, mmol/L153.3 ± 1.0152.5 ± 1.1
Potassium, mmol/L6.9 ± 0.27.6 ± 0.5
Chloride, mmol/L113.0 ± 2.1115.2 ± 0.6
Creatinine, mg/dL0.1 ± 0.00.1 ± 0.0
BUN, mg/dL24.2 ± 2.521.3 ± 0.9
Calcium, mmol/L2.3 ± 0.02.3 ± 0.0
Magnesium, mmol/L1.3 ± 0.01.2 ± 0.0
Phosphorous, mg/dL7.9 ± 0.18.3 ± 0.3
Alkaline phosphatase, U/L82.5 ± 6.288.2 ± 10.5
ALT, U/L125.0 ± 29.7198.8 ± 56.7
AST, U/L232.0 ± 20.1248.3 ± 14.3
Amylase, U/L>650.0 ± 0.0>650 ± 0.0
CK, total, U/L>800.0 ± 0.0>800 ± 0.0
Lactate dehydrogenase, U/L>600.0 ± 0.0>600 ± 0.0
Protein, total, g/dL5.3 ± 0.05.2 ± 0.2
Uric acid, mg/dL3.5 ± 0.03.0 ± 0.1
Spleen T-cell proliferationn = 8n = 8
Media, 10−3 cpm3.9 ± 0.55.5 ± 1.5
CD3, 10−3 cpm16.5 ± 1.627.8 ± 2.9b
Spleen T cellsn = 8n = 8
% total cells labeled
CD4+22.9 ± 1.216.8 ± 1.5a
CD8+29.8 ± 1.510.5 ± 1.9c
TH112.6 ± 1.313.4 ± 1.1
TH171.4 ± 0.13.4 ± 0.5b
Tregs26.9 ± 1.127.2 ± 1.1

NOTE: Mice were administered 4NQO diluted in the drinking water for 14 weeks, divided into 2 groups, and given either daily i.p. injections of metformin at a dose of 50 mg/kg/d or an equal volume of sterile saline for a period of 8 weeks, as described in Fig. 3. Mice were euthanized on week 22 from the initiation of 4NQO exposure, and serum and spleen T cells isolated as described in Materials and Methods. Serum components, spleen T-cell proliferation, and spleen T-cell subtypes were analyzed as described in Materials and Methods. Metformin exerted a very limited impact on serum components and metabolic markers and did not reduce the T-cell proliferative response. Metformin significantly enhanced TH17 cells without changing TH1 and Foxp3+ Tregs, an effect that is under current investigation.