Table 2. Changes of memory ability in different groups of rats (memory numbers).

Groups	Before treatment	After teatment
		2 weeks	4 weeks	6 weeks	8 weeks
Control	8.0±0.9	7.3±0.5	7.5±0.5	7.7±0.8	7.7±0.5
Gal	7.8±1.0	7.0±0.9	5.8±0.8	5.0±0.9**	3.7±0.8**
EGB-L	7.7±0.5	6.8±0.8	6.0±0.9	5.2±1.0**	4.2±1.0**
EGB-M	8.2±0.8	7.2±0.4	6.3±0.8	6.7±0.5#	6.5±0.5##
EGB-H	8.3±0.8	7.2±0.8	6.5±0.8	6.8±0.4##	6.7±0.5##

Gal: rats in the galactose group were treated with D-galactose (100 mg/kg, peritoneal injection each day).EGB-L: rats in the low-dose. Ginkgo biloba leaf extract group received 0.875 mg/kg Ginkgo biloba leaf extract. EGB-M: rats in the middle-dose Ginkgo biloba leaf extract group re-ceived 1.75 mg/kg Ginkgo biloba leaf extract. EGB-H, rats in the high-dose Ginkgo biloba leaf extract group received 3.5 mg/kg biloba leaf extract. *P < 0.05, **P < 0.01 vs Control group; ^#P < 0.05, ^##P < 0.01 vs Gal group.