Table 3.

Redox-homeostasis enzyme activity.

	Liver
	Young		Middle-age		Old
	Control	Metformin	Control	Metformin	Control	Metformin
	GR	99.1 ± 26.1	145.1 ± 24.0	74.5 ± 21.2	74.5 ±17.5	125.9 ± 34.8	115.4 ± 31.7
GPx	399.8 ± 25.2	409.8 ± 14.4	407.2 ± 17.3	428.5 ±15.9	376.6 ± 18.1	413.3 ± 22.8
Grdx	5.2 ± 0.1	5.5 ± 0.2	5.4 ± 0.3	6.1 ± 0.2	6.4 ± 0.6	5.8 ± 0.5
TrxR	3.9 ± 0.54	6.7 ± 0.31#	3.7 ± 0.55	4.0 ± 0.47*	5.5 ± 0.66	4.8 ± 0.76*
GST	388.6 ± 19.6	433.9 ± 21.1	419.4 ± 16.4	399.8 ±10.5	453.1 ± 34.2	398.1 ± 39.1
GCL	59.9 ± 3.8	68.2 ± 2.5	68.3 ± 3.6	68.4 ± 4.7	68.1 ± 4.6	62.9 ± 3.3

Each value represents the mean ± SE of 4-8 mice.

Abbreviations: GR, Glutathione reductase activity (U/mg protein); GPx, Glutathione peroxidase activity (U/mg protein); Grdx, Glutaredoxin activity (1nmol NADPH utilized/min/mg protein); TrxR, Thioredoxin reductase activity (U/mg protein); GST, Glutathione S-Transferase activity (U/mg protein); GCL, Glutamate Cysteine Ligase activity (1 nmol NADH utilized/min/mg protein)

^*Significantly different from treatment-matched young, p<0.05

^#Significantly different from age-matched control, p<0.05