Objective To explore the potential mechanism of"hot flashes"in mice with type 2 diabetes with yin deficiency syndrome.Methods Ninety-nine 8-week-old db/db mice with fasting blood glucose≥16.7 mmol·L-1 were divided into yin deficiency syndrome group,type 2 diabetes group,type 2 diabetes with yin deficiency syndrome group,type 2 diabetes with Liuwei Dihuang Decoction low,medium,high-dose group,type 2 diabetes with yin-deficiency syndrome and Liuwei Dihuang Decoction low,middle,high-dose groups,21 littermates of wild control male m/m mice were control group.The model was established by the method of"heat engenders yin deficiency",and the performance of yin deficiency syndrome in mice was evaluated after 4 weeks.Afterwards,the corresponding doses of Liuwei Dihuang Decoction group were given by gavage for 4 weeks.During the experiment,the rectal temperature,the temperature of the precordial area,and the temperature of the limbs and paws were measured once a week at 8:30,15:00,and 20:00.Western blot was used to observe the expression of biological rhythm-related proteins in the hypothalamus and liver.Results The experimental study showed that the yin deficiency syndrome model of type 2 diabetes could be established by using the method of overheating and injuring the yin.The rhythm changes of Liuwei Dihuang Decoction showed that the high-dose group could effectively restore the body temperature rhythm.The expression of rhythm factors Clock and Cry2 increased in both the hypothalamus and liver;in the hypothalamus,the central rhythm regulation center,the expressions of Per2 and Cry2 increased significantly;in the peripheral target organ liver,the expressions of Bmal1,Per3 and Cry1 increased more significantly.Conclusion The abnormal expression of biological rhythm protein in the liver and hypothalamus may be one of the important mechanisms leading to the characteristics of"hot flashes"in type 2 diabetes with yin deficiency.

ABSTRACTOBJECTIVE To establish UHPLC?MS/MS method to determine geniposidic acid in rat plasma and to investigate the effect of salt processing on pharmacokinetics of geniposidic acid in Eucommia ulmoides Oliver.METHODS Chromato-graphic columnBEH?C18100 mm×2.1 mm1.7 μmthe mobile phaseacetonitrile?0.1% formic acid aqueous solution. The gradient elution program was performed at a flow rate of 0.3 mL/min.RESULTS The main pharmacokinetic parameters of geniposidic acid in raw and salt products were thatAUC0?t were1 47.18±272.282 120.694± 664.532ng.h/mLAUC0?∞ were1 564.42±273.972 145.61 ±659.983ng.h/mLCmax were517.59±51.24733.292±261.34ng/mLMRT were2.68±0.112.551±0.08hT1/2 were1.37±0.081.43±0.17hTmax were1.52±0.11.51± 0.1h.CONCLUSION Salt processing can obviously enhance the absorption of geniposidic acid in Eucommia ulmoides Oliverand increase the bioavailability.