DHM improves cognitive dysfunction in T2DM rats by inhibiting hippocampal endoplasmic reticulum stress / 中国药理学通报

Aim To investigate the effeet of dihydro- myricetin ( DHM ) on cognitive dysfunction in type 2 diabetes mellitus ( T2DM) rats and its mechanism.Methods SD rats were randomly divided into the normal control group ( n = 56) : normal diet and citrate buffer solution (30 mg • kg 1 ) ; T2DM model group (n =60) : high glucose, fat and low dose STZ ( 30 mg • kg 1 ) ( Four unsuccessful rats were eliminated ).Then rats in the above two groups were treated with or without DHM (250 mg • kg 1 • d intragastric).After 12 weeks, eight rats in each group were randomly selected to perform Morris water maze and Y maze test to observe the effect of DHM on cognitive function of rats.The remaining rats in each group were injected ERS antagonist tauroursodeoxycholic acid ( TUDCA ) 10 jxg • d 1 or ERS activator tunicamycin (TUN) 10 jxL, respectively.After the behavioral analysis, the hippocampal tissues of rats were taken out.The expressions of EH stress related proteins GRP78 and P- PERK were detected by Western blot.Results Both DHM and TUDCA could improve cognitive dysfunction in T2DM rats.On the contrary, TIJN reduced the effect of DHM on cognitive dysfunction in T2DM rats.TUDCA decreased the expression of GRP78 and p- PERK proteins in T2DM rats, while TUN increased the expression of GRP78 and p-PERK proteins in T2DM rats treated by DHM.Conclusion DHM improves cognitive dysfunction in T2DM rats, and the mechanism may be related to the inhibition of endoplasmic reticulum stress.

Dihydromyricin inhibited hepatic lipid deposition induced by high-fat diet in obese mice by activating SIRT1-AMPK pathway / 中国药理学通报

Aim To investigate the effect of dihydromyricetin (DHM) on lipid accumulation in liver of obese mice induced by high fat diet and its mechanism. Methods Sixty C57BL/6J mices were randomly divided into six groups (n = 10); (1)ND group; normal diet, (2)ND + L-DHM group; normal diet and treatment with low-dose DHM (125 mg • kg

Dihydromyricetin promoted browning of subscapular adipose tissues in obese mice fed with high-fat diet via activating AMPK-PGC1 a-Sirtl signaling pathway / 中国药理学通报

Aim To observe the effect of dihydromyricetin (DHM) on the browning of subscapular adipose tissues in the high-fat diet fed obese mice, and clarify the mechanism. Methods C57BL/6J mice were fed with normal and high-fat diet, and were treated with or without low dose (125 mg • kg"1 • d"1) or high dose (250 mg • kg"1 • d"1) DHM for 16W. The body mass of mice was measured every four weeks during the experiment. After 16 weeks, the mice were fasted overnight. Blood samples were taken for fasting blood glucose. The mice were then sacrificed and the body length measured. The Lee' s index was calculated. The size of the subscapular adipocytes was observed by HE staining. The mRNA and protein expression of uncoupling protein 1 (UCP1) , PR domain containing 16 (Prdml6) , adenylate-activated protein kinase (AMPK) , peroxisome proliferator-activated receptor gamma-assisted activator alpha (PGCla) and silencing signal regulator 1 (Sirtl) were assessed by real time quantitative PCR and Western blot assay. Results Compared with normal control group (ND group) , the body mass of mice in high-fat diet group (HFD group) significantly increased, suggesting that the obese mice model was successfully replicated. In addition , blood glucose, Lee' s index and the fat cell diameter of the subscapular adipose tissues in HFD group all significantly increased, while the mRNA and pro-tein expression of UCP1, Prdml6, AMPK, PGCla and Sirtl significantly decreased. DHM markedly re-versed the changes of the above indexes of HFD mice, but DHM did not significantly affect the above indexes of normal mice. Conclusions Dihydromyricetin promotes the browning of subscapular adipose tissues in mice fed with high-fat diet, which might be via activating AMPK-PGC1 a-Sirtl signaling pathway.