Liuwei Dihuangtang Alleviates Myelin Injury in vHIP and Depression-like Behavior of Diabetes Mellitus Combined with Comorbid Depression Rats via AMPK/Akt/GSK3β/Nrf2 Pathway
10.13422/j.cnki.syfjx.20212402
- VernacularTitle:六味地黄汤通过调节AMPK/Akt/GSK3β/Nrf2通路减轻糖尿病抑郁大鼠vHIP髓鞘损伤及抑郁样行为
- Author:
Fang HUANG
1
;
Zi-hu TAN
1
;
Nan SHAN
1
;
Wen-jing YAN
1
Author Information
1. Hubei University of Chinese Medicine，Wuhan 430065，China
- Publication Type:Journal Article
- Keywords:
diabetes;
depression;
myelin sheath;
oxidative stress;
Liuwei Dihuangtang
- From:
Chinese Journal of Experimental Traditional Medical Formulae
2022;28(2):38-46
- CountryChina
- Language:Chinese
-
Abstract:
ObjectiveTo observe the effect of Liuwei Dihuangtang on depression-like behavior of diabetes mellitus combined with comorbid depression （DD） rats， so as to explore its action mechanism. MethodFifty male SD rats of SPF grade were fed with high fat diet and injected with low-dose streptozotocin （STZ） via tail vein for inducing diabetes. Afterwards， the diabetic rats were exposed to chronic unpredictable mild stress （CUMS） for 28 d. The successfully modeled DD rats were randomly divided into five groups： model group， fluoxetine （10 mg·kg-1·d-1） group， and low-， medium-， and high-dose （3.375， 6.75， 13.5 g·kg-1·d-1） Liuwei Dihuangtang groups， with 10 in each group. Another 10 rats were classified into the normal control group and treated with intragastric administration of normal saline for four weeks. The tail suspension test and open field test were conducted to evaluate the depressive-like phenotype of rats. The contents of malondialdehyde （MDA）， reactive oxygen species （ROS）， 8-hydroxy-2 deoxyguanosine （8-OHdG）， superoxide dismutase （SOD）， and glutathione （GSH） in ventral hippocampus （vHIP） were measured by enzyme-linked immunosorbent assay （ELISA）， and the myelin basic protein （MBP） expression in vHIP by immunofluorescence assay. The expression levels of MBP， myelin protein lipoprotein （PLP）， myelin oligodendrocyte glycoprotein （MOG）， phosphorylated adenosine 5'-monophosphate-activated protein kinase （p-AMPK）/AMPK， phosphorylated protein kinase B （p-Akt）/Akt， phosphorylated glycogen synthase kinase 3β （p-GSK3β）/GSK3β， and nuclear factor erythroid-2 related factor 2（Nrf2） were determined by Western blotting. ResultCompared with the normal control group， the model group exhibited significantly prolonged immobility in the tail suspension test （P<0.01） and shortened residence at the central area in the open field test （P<0.01）. The immobility time in the medium- and high-dose Liuwei Dihuangtang groups declined to different degrees as compared with that of the model group （P<0.01）， while the residence time at the central area was significantly increased （P<0.05， P<0.01）. Compared with the normal control group， the model group displayed down-regulated MBP， PLP， and MOG protein expression in vHIP （P<0.01）. Compared with the model group， Liuwei Dihuangtang at the low dose up-regulated the expression of MBP （P<0.05）， but did not obviously affect the expression of MOG and PLP. Fluoxetine and Liuwei Dihuangtang at the medium and high doses up-regulated the expression of MBP， PLP， and MOG （P<0.05， P<0.01）. Comparison with the normal control group revealed that the MBP fluorescence intensity in vHIP of the model group was significantly weakened （P<0.01）. After the intervention， the MBP fluorescence intensities in the medium- and high-dose Liuwei Dihuangtang groups and fluoxetine group were enhanced in contrast to that of the model group （P<0.05， P<0.01）. SOD and GSH in the model group were lower than those in the normal control group （P<0.01）， whereas the MDA， ROS， and 8-OHdG expression levels were higher （P<0.01）. Compared with the model group， Liuwei Dihuangtang at the medium and high doses and fluoxetine all down-regulated the expression levels of MDA， ROS， and 8-OHdG （P<0.05，P<0.01）， while up-regulated SOD and GSH expression （P<0.05，P<0.01）. The expression levels of p-AMPK， p-Akt， and Nrf2 in the model group were down-regulated as compared with those in the control group， and the expression of p-GSK3β was up-regulated （P <0.01）. As demonstrated by comparison with the model group， the protein expression of p-AMPK in the low-dose Liuwei Dihuangtang group was elevated （P<0.05）， while p-Akt and Nrf2 were slightly increased， exhibiting no statistical significant difference. However， the protein expression levels of p-AMPK， p-Akt， and Nrf2 in the medium- and high-dose Liuwei Dihuangtang groups and fluoxetine group were up-regulated， while those of p-GSK3β were down-regulated （P<0.05，P<0.01）. ConclusionLiuwei Dihuangtang improves the depressive-like behavior of DD rats， which may be related to its activation of the AMPK/Akt/GSK3β/NRF2 pathway， regulation of the oxidative stress in vHIP， and enhancement of myelin repair.
