ObjectiveTo investigate the therapeutic effect of sequential administration of Dihuang Baoyuan granules （DHBY， the prescription for consolidating body resistance） and Fuling Yunhua granules （FLYH， the prescription for treating symptoms） on spontaneous type 2 diabetes mellitus （T2DM） in mice. MethodsAccording to the fasting blood glucose （FBG） level， 12-week-old db/db mice were randomized into six groups： model， DHBY （18.02 g·kg^-1）， FLYH （14.80 g·kg^-1）， sequential administration 1 （SEQ-1， DHBY 18.02 g·kg^-1+FLYH 14.80 g·kg^-1）， sequential administration 2 （SEQ-2， FLYH 14.80 g·kg^-1+DHBY 18.02 g·kg^-1）， and dapagliflozin （Dapa， 1.3 mg·kg^-1）. The m/m mice in the same litter were selected as the normal group. The mice were administrated with corresponding drugs by gavage for 8 consecutive weeks. During the 8 weeks of drug administration and 2 weeks after withdrawal， the retinal thickness， FBG， hemoglobin A1c （HbA1c）， and insulin were determined， and histopathological changes of the pancreas， liver， kidney， and retina were observed by hematoxylin-eosin （HE） staining. ResultsCompared with the model group， SEQ-1 for 4 weeks lowered the FBG level （P<0.05）， raised the insulin level， decreased the triglyceride （TG） level （P<0.05）， increased the number of optic ganglion cells and diminished vacuolar degeneration of pancreatic islet and liver. SEQ-2 lowered FBG and HbA1c levels （P<0.05）， rose the insulin level， increased the retinal thickness and the number of optic ganglion cells （P<0.05）， and alleviated vacuolar degeneration of pancreatic islet and liver. Two weeks after drug withdrawal， Dapa tended to increase FBG and HbA1c compared with those at the time of drug withdrawal. However， the levels of FBG and HbA1c in the SEQ-2 group remained decreasing （P<0.05）. ConclusionSEQ-1 and SEQ-2 can lower the blood glucose level and ameliorate diabetic retinopathy， and SEQ-2 outperformed DHBY and FLYH in lowering the blood glucose level. Moreover， SEQ-2 can maintain the blood glucose-lowering effect after drug withdrawal.

ObjectiveTo investigate the therapeutic effect of sequential administration of Dihuang Baoyuan granules （DHBY， the prescription for consolidating body resistance） and Fuling Yunhua granules （FLYH， the prescription for treating symptoms） on spontaneous type 2 diabetes mellitus （T2DM） in mice. MethodsAccording to the fasting blood glucose （FBG） level， 12-week-old db/db mice were randomized into six groups： model， DHBY （18.02 g·kg^-1）， FLYH （14.80 g·kg^-1）， sequential administration 1 （SEQ-1， DHBY 18.02 g·kg^-1+FLYH 14.80 g·kg^-1）， sequential administration 2 （SEQ-2， FLYH 14.80 g·kg^-1+DHBY 18.02 g·kg^-1）， and dapagliflozin （Dapa， 1.3 mg·kg^-1）. The m/m mice in the same litter were selected as the normal group. The mice were administrated with corresponding drugs by gavage for 8 consecutive weeks. During the 8 weeks of drug administration and 2 weeks after withdrawal， the retinal thickness， FBG， hemoglobin A1c （HbA1c）， and insulin were determined， and histopathological changes of the pancreas， liver， kidney， and retina were observed by hematoxylin-eosin （HE） staining. ResultsCompared with the model group， SEQ-1 for 4 weeks lowered the FBG level （P<0.05）， raised the insulin level， decreased the triglyceride （TG） level （P<0.05）， increased the number of optic ganglion cells and diminished vacuolar degeneration of pancreatic islet and liver. SEQ-2 lowered FBG and HbA1c levels （P<0.05）， rose the insulin level， increased the retinal thickness and the number of optic ganglion cells （P<0.05）， and alleviated vacuolar degeneration of pancreatic islet and liver. Two weeks after drug withdrawal， Dapa tended to increase FBG and HbA1c compared with those at the time of drug withdrawal. However， the levels of FBG and HbA1c in the SEQ-2 group remained decreasing （P<0.05）. ConclusionSEQ-1 and SEQ-2 can lower the blood glucose level and ameliorate diabetic retinopathy， and SEQ-2 outperformed DHBY and FLYH in lowering the blood glucose level. Moreover， SEQ-2 can maintain the blood glucose-lowering effect after drug withdrawal.