Objective:To observe the effect of water extruct from cortex of Berberi dictyophylla (BDCE) on diabetic retinopathy (DR) in spontaneous type 2 diabetic db/db mice. Method:Eighteen-week-old db/db mice were selected

with their thin db/m mice as normal controls. The db/db mice were randomly divided into 6 treatment groups:model control (db/db) group

high and middle and low dosage groups of BDCE (1.50

0.75

0.38 g·kg-1)

calcium-dobesilate group (0.23 g·kg-1)

berberine hydrochloride group (0.135 g·kg-1). During the two-month intragastric administration

all of the mice were weighed and measured for their fasting blood glucose level every two weeks

all the mice were put to death and their eyeballs were taken out at the end of the two-month treatment. Conventional hematoxylin and eosin(HE) staining was performed to observe pathologic change

retina stretched preparation was performed to observe microvascular changes and calculated endothelial/pericytescells (E/P) value. Result:Compared to db/m group

db/db group was significantly higher (P<0.01) in body mass

fasting blood glucose level (P<0.01) and E/P value (P<0.05) of retina microvascular

and showed capillary congestion

expansion and damage of retina. Compared to db/db group

all treatment groups were not significantly higher in body mass;berberine hydrochloride group and low dosage of BDCE group were significantly lower in fasting blood glucose level (P<0.01)

high and middle dosage group of BDCE were significantly lower in blood glucose level (P<0.05)

calcium-dobesilate group showed no significant change in fasting blood glucose level;significantly lower in E/P value (P<0.05) was obtained in high BDCE group

while all of other treatment groups showed no significant change in E/P value

and retinal damage were relieved in all BDCE-treated groups. Conclusion:Spontaneously diabetic db/db mice can be considered as an animal model for human DR. BDCE shows good preventive effects for DR

significantly decreases in blood glucose level

relieves spontaneous retinal microvascular damage in diabetic mice

and protects retinal capillaries while preventing the formation of new blood vessels.