Table 4.

Redox-homeostasis enzymes activity detailing group means and standard errors for enzymatic activity in the cerebral cortex and hippocampus

	Cerebral cortex						Hippocampus
	Young		Middle-age		Old		Young		Middle-age		Old
	Control	Metformin	Control	Metformin	Control	Metformin	Control	Metformin	Control	Metformin	Control	Metformin
GR	174.1 ± 9.5	174.2 ± 8.7	172.9 ± 5.9	187.8 ± 8.9	176.2 ± 5.6	193.2 ± 9.6	212.3 ± 13.3	203.0 ± 9.3	236.7 ± 20.8	225.8 ± 15.5	226.1 ± 32.1	203.7 ± 8.8
GPx	16.7 ± 1.1	19.0 ± 0.5#	19.2 ± 0.7*	19.1 ± 0.6	18.2 ± 1.1	18.3 ± 0.4	30.2 ± 3.2	30.7 ±2.3	30.6 ± 1.1	30.2 ± 2.2	34.5 ± 3.3	35.9 ± 2.5
Grdx	29.5 ± 0.9	29.2 ± 0.4	29.0 ± 0.5	29.2 ± 0.6	29.5 ± 0.7	29.4 ± 0.7	31.8 ± 1.2	34.0 ± 1.7	32.7 ± 0.8	34.9 ± 1.4	33.8 ± 2.1	34.4 ± 1.1
TrxR	11.8 ± 0.8	12.1 ± 0.7	11.2 ± 0.5	12.5 ± 0.4	12.4 ± 1.0	12.2 ± 0.5	14.5 ± 1.26	15.0 ± 2.60	16.0 ± 1.98	15.4 ± 1.50	18.4 ± 3.63	13.7 ± 1.30
GST	40.3 ± 2.6	48.9 ± 3.1#	53.7 ± 2.4*	55.2 ± 2.5	56.7 ± 4.3*	50.3 ± 3.1	177.9 ± 11.3	166.2 ± 11.4	197.5 ± 13.8	201.5 ±7.4	225.3 ± 25.4*	186.2 ± 9.5
GCL	71.5 ± 3.7	73.2 ± 3.5	79.5 ± 3.1	79.6 ± 3.8	81.4 ± 3.6	82.5 ± 3.8	N/A	N/A	N/A	N/A	N/A	N/A

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 (1nmol NADH utilized/min/mg protein)

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

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