ABSTRACT
ObjectiveTo investigate the effect of Gegen Qinliantang on glucose and lipid metabolism in the rat model of catch-up growth （CUG） induced by a high-fat diet and the underlying mechanism. MethodA total of 60 SD rats were randomized into a normal control group （n=18） and a modeling group （n=42）. The rat model of CUG was established with a restricted diet followed by a high-fat diet， and the changes of general status and body weight were observed. The levels of fasting blood glucose （FBG）， fasting insulin （FINS）， triglyceride （TG）， and total cholesterol （TC） were measured in 6 rats in each group at the end of the 4th and 8th week， respectively. The homeostasis model assessment of insulin resistance index （HOMA-IR） was calculated， and the insulin sensitivity and body composition changes of CUG rats were evaluated. The successfully modeled rats were assigned into 6 groups： normal control， model， high-， medium-， and low-dose Gegen Qinliantang （2.5， 5， 10 g·kg-1）， and pioglitazone （3.125 mg·kg-1）. The rats were administrated with corresponding drugs by gavage for 6 weeks， and the normal control group and model group were administrated with the same amount of normal saline. During the experiment period， the changes of body weight were recorded， and the FBG， FINS， HOMA-IR， TG， and TC were determined at the end of the experiment. Hematoxylin-eosin （HE） staining was employed to observe the pathological changes of skeletal muscle in rats. The levels of reactive oxygen species （ROS） and malondialdehyde （MDA） in the skeletal muscle were measured strictly according to the manuals of the reagent kits. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was performed to measure the mRNA levels of silencing information regulator 1 （SIRT1）， peroxisome proliferator-activated receptor-gamma coactivator1α （PGC1α）， and nuclear respiratory factor 1 （Nrf1） in the skeletal muscle. Western blot and immunohistochemistry were employed to assess the expression of SIRT1， PGC1α， and Nrf1 in the skeletal muscle. ResultCompared with the normal control group， the model group presented elevated levels of FBG， FINS， TG， and TC （P<0.05， P<0.01）， increased HOMA-IR （P<0.01）， increased diameter of muscle fibers and adipocytes between muscle cells in the skeletal muscle， rising levels of ROS and MDA in the skeletal muscle （P<0.01）， and down-regulated mRNA and protein levels of SIRT1， PGC1α， and Nrf1 （P<0.05， P<0.01）. Compared with the model group， Gegen Qinliantang （especially the medium and high doses） and pioglitazone decreased the body weight， FINS， HOMA-IR， and TG （P<0.05， P<0.01） and reduced interstitial components such as intermuscular fat in the skeletal muscles and the diameter of muscle fibers. Furthermore， the drugs lowerd the levels of ROS and MDA （P<0.05， P<0.01） and up-regulated the mRNA and protein levels of SIRT1， PGC1α， and Nrf1 （P<0.05， P<0.01） in the skeletal muscle. ConclusionGegen Qinliantang can ameliorate the glucose and lipid metabolism disorders and insulin resistance in CUG rats by regulating the SIRT1/PGC1α/Nrf1 signaling pathway.
ABSTRACT
ObjectiveTo investigate the effect of Tangbikang granules on oxidative stress of sciatic nerve in diabetic rats by regulating adenylate activated protein kinase/peroxisome proliferator-activated receptor γ coactivator-1α/mitochondrial Sirtuins 3 （AMPK/PGC-1α/SIRT3） signaling pathway. MethodThe spontaneous obesity type 2 diabetes model was established using ZDF rats. After modeling， they were randomly divided into high， medium， and low dose Tangbikang granule groups （2.5， 1.25， 0.625 g·kg-1·d-1） and lipoic acid group （0.026 8 g·kg-1·d-1）， and the normal group was set up. The rats were administered continuously for 12 weeks after modeling. The blood glucose of rats was detected before intervention and at 4， 8， 12 weeks after intervention. At the 12th week， motor nerve conduction velocity （MNCV）， sensory nerve conduction velocity （SNCV）， nerve blood flow velocity， mechanical pain threshold， and thermal pain threshold were detected. The sciatic nerve was taken for hematoxylin-eosin （HE） staining to observe the tissue morphology. The ultrastructure of the sciatic nerve was observed by transmission electron microscope. The expression levels of superoxide dismutase （SOD）， malondialdehyde （MDA）， interleukin-1β （IL-1β）， and tumor necrosis factor-α （TNF-α） in sciatic nerve were determined by enzyme-related immunosorbent assay （ELISA）. The mRNA expressions of AMPKα， AMPKβ， PGC-1α， and SIRT3 in sciatic nerve were determined by real-time polymerase chain reaction （Real-time PCR）. ResultCompared with the normal group， fasting blood glucose in the model group was increased at each time point （P<0.01）. The mechanical pain threshold was decreased （P<0.05）， and the incubation time of the hot plate was extended （P<0.01）. MNCV， SNCV， and nerve blood flow velocity decreased （P<0.05）. The expression level of SOD was decreased （P<0.01）. The expression levels of MDA， IL-1β， and TNF-α were increased （P<0.01）. The mRNA expression levels of AMPKα， AMPKβ， PGC-1α， and SIRT3 were decreased （P<0.01）. The structure of sciatic nerve fibers in the model group was loose， and the arrangement was disordered. The demyelination change was obvious. Compared with the model group， the fasting blood glucose of rats in the high dose Tangbikang granule group was decreased after the intervention of eight weeks and 12 weeks （P<0.01）. The mechanical pain threshold increased （P<0.05）. The incubation time of the hot plate was shortened （P<0.01）. MNCV， SNCV， and Flux increased （P<0.05）. The expression level of SOD was increased （P<0.01）. The expression levels of MDA， IL-1β， and TNF-α were decreased （P<0.01）. The mRNA expression levels of AMPKα， AMPKβ， PGC-1α， and SIRT3 were increased （P<0.01）. The sciatic nerve fibers in the high-dose Tangbikang granule group were tighter and more neatly arranged， with only a few demyelinating changes. The high， medium， and low dose Tangbikang granule groups showed a significant dose-effect trend. ConclusionTangbikang granules may improve sciatic nerve function in diabetic rats by regulating AMPK/PGC-1α/SIRT3 signaling pathway partly to inhibit oxidative stress.
ABSTRACT
ObjectiveTo investigate the effect and mechanism of total saponins from Panax japonicus （TSPJ） on white adipose tissue （WAT） browning/brown adipose tissue （BAT） activation in C57BL6/J male mice fed on a high-fat diet （HFD）. MethodThirty-two C57BL6/J male mice （8-week-old） were randomly divided into a normal group， a model group， a low-dose TSPJ group， and a high-dose TSPJ group. The mice in the low-dose and high-dose TSPJ groups were given TSPJ for four months by gavage at 25， 75 mg·kg-1·d-1， respectively， and those in the other groups were given 0.5% sodium carboxymethyl cellulose （CMC-Na） accordingly. After four months of feeding， all mice were placed at 4 ℃ for acute cold exposure， and the core body temperature was monitored. Subsequently， all mice were sacrificed， and BAT and inguinal WAT （iWAT） were separated rapidly to detect the corresponding indexes. Hematoxylin-eosin （HE） staining was used to observe the morphological changes in each group. The effect of TSPJ on the mRNA expression of uncoupling protein 1 （UCP1）， fatty acid-binding protein 4 （FABP4）， cytochrome C （CytC）， PR domain-containing protein 16 （PRDM16）， elongation of very long chain fatty acids protein 3 （ELOVL3）， peroxisome proliferator-activated receptor γ （PPARγ）， and peroxisome proliferator-activated receptor-γ coactivator-1α （PGC-1α） in iWAT and BAT was detected by Real-time polymerase chain reaction （Real-time PCR）. Western blot was also used to detect the protein expression of UCP1， PRDM16， PPARγ， and PGC-1α in BAT and iWAT of each group. The effect of TSPJ on UCP1 expression in BAT and iWAT was detected by immunohistochemistry. Result① Compared with the model group， TSPJ could decrease the body weight and proportions of iWAT and BAT in the HFD-induced mice （P<0.05， P<0.01）. ② The body temperature of mice in the model group decreased compared with that in the normal group in the acute cold exposure tolerance test （P<0.05）. The body temperature in the high-dose TSPJ group increased compared with that in the model group （P<0.01）. ③ Compared with the normal group， the model group showed increased adipocyte diameter in iWAT and BAT and decreased number of adipocytes per unit area. Compared with the model group， the TSPJ groups showed significantly reduced cell diameter and increased number of cells per unit area， especially in the high-dose TSPJ group. ④ Compared with the normal group， the model group showed decreased mRNA expression of FABP4， UCP1， CytC， PRDM16， ELOVL3， PGC-1α， and PPARγ in adipose tissues of mice （P<0.05， P<0.01）. Compared with the model group， after intervention with TSPJ， the mRNA expression was significantly up-regulated （P<0.05， P<0.01）. ⑤ Compared with the normal group， the model group showed decreased protein expression of UCP1， PRDM16， PPARγ， and PGC-1α in adipose tissues of mice （P<0.05， P<0.01）. Compared with the model group， after intervention with TSPJ， the protein expression increased significantly （P<0.05， P<0.01）. ConclusionTSPJ could induce the browning of iWAT/BAT activation and enhance adaptive thermogenesis in obese mice induced by HFD. The underlying mechanism may be attributed to the activation of the PPARγ/PGC-1α signaling pathway.
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ObjectiveTo observe the effect of salvianolate on the protein expressions of adenosine monophosphate （AMP）-activated protein kinase （AMPK）， silent information regulator 1 （SIRT1） and peroxisome proliferator-activated receptor-γ coactivator-1α （PGC-1α）， autophagy and apoptosis in kidney tissue of rats with membranous nephropathy （MN）， and to explore its possible molecular mechanism against MN. MethodEighty male SD rats were randomly divided into normal group， model group， benazepril hydrochloride group （10 mg·kg-1）， and salvianolate low-， medium-， and high-dose groups （16.7， 33.3 and 66.7 mg·kg-1）. The rats were modeled by injection of cationized bovine serum albumin （C-BSA） into the tail vein. After successful modeling， rats in the administration groups were given corresponding doses of drugs for 4 consecutive weeks， and then 24-hour urine， serum and kidney tissue were collected for the detection of 24-hour urinary protein （UTP）， blood urea nitrogen （BUN）， serum creatinine （SCr）， interleukin-6 （IL-6）， tumor necrosis factor-α （TNF-α）， C reactive protein （CRP）， glutathione peroxidase （GSH-Px）， superoxide dismutase （SOD）， and malondialdehyde （MDA）. The pathological changes of kidneys were observed by light microscope， electron microscope and immunofluorescence. Western blot was used to detect the protein expressions of phospho-AMPK （p-AMPK）， AMPK， phospho-SIRT1 （p-SIRT1）， SIRT1 and PGC-1α in rat kidney tissue. The protein expressions of autophagy-specific gene （Beclin-1）， microtubule-associated protein 1 light chain 3 （LC3） Ⅱ， ubiquitin-binding protein （p62）， B cell lymphoma （Bcl-2）， Bcl-2-associated X （Bax）， and cysteine aspartic protease-7 （Caspase-7） in rat kidney tissue were determined by immunohistochemistry （IHC）. ResultCompared with the conditions in the normal group， the levels of UTP， IL-6， TNF-α， CRP and MDA in the model group were increased （P<0.05） while the levels of SOD and GSH-Px were decreased （P<0.05）， and there was no difference in BUN and SCr. Compared with the model group， the administration groups had lowered UTP， IL-6， TNF-α， CRP and MDA （P<0.05） while elevated SOD and GSH-Px （P<0.05）. It could be seen from hematoxylin and eosin （HE） staining， Masson staining， immunofluorescence and electron microscopy that the pathological damage of rat kidney tissue in the model group was significant， but after treatment with benazepril hydrochloride and salvianolate， the pathological damage of kidney cells was gradually improved. The expressions of p-AMPK/AMPK， p-SIRT1/SIRT1， PGC-1α， Bcl-2， Beclin-1 and LC3Ⅱ in rat kidney in the model group were lower than those in the normal group （P<0.05） while the expressions of Bax， Caspase-7 and p62 were higher （P<0.05）. Compared with the model group， benazepril hydrochloride group and salvianolate groups had an up-regulation in the expressions of p-AMPK/AMPK， p-SIRT1/SIRT1， PGC-1α， Bcl-2， Beclin-1 and LC3Ⅱ in the kidney （P<0.05） while a down-regulation in the expressions of Bax， Caspase-7 and p62 （P<0.05）. ConclusionThe protective effect of salvianolate on the kidneys of MN rats may be related to the activation of AMPK/SIRT1/PGC-1α signaling pathway， the up-regulation of autophagy and the reduction of apoptosis.
ABSTRACT
ObjectiveTo reveal the effect of Wenxin prescription on mitochondrial energy metabolism and silent information regulator 1 （SIRT1）/peroxisome proliferator-activated receptor-γ coactivator-1α （PGC-1α）/recombinant estrogen-related receptor α （ERRα） signaling pathway in rats with myocardial ischemia-reperfusion injury. MethodTotally 90 male Wistar rats of SPF grade were randomly assigned into a sham operation group， a model group， and low-， medium-， and high-dose Wenxin prescription groups， with 18 rats in each group. The rats in low-， medium-， and high-dose Wenxin prescription groups were administrated with 0.99， 1.98， and 3.96 g·kg-1 granules by gavage， respectively， and those in the sham operation group and model group with the same amount of normal saline. Twenty-one days after pre-administration， the rat model of myocardial ischemia-reperfusion injury was established by ligation of the left anterior descending coronary artery for 30 min and reperfusion for 2 h， and the rats in the sham operation group were only threaded without ligation. Myocardial infarction area was observed through 2，3，5-triphenyl-2h-tetrazolium chloride （TTC） staining， and the myocardial histopathology through hematoxylin-eosin （HE） staining. The levels of creatine kinase-MB （CK-MB） and lactate dehydrogenase （LDH） in serum， cytochrome C oxidase （CCO） and succinate dehydrogenase （SDH） in mitochondrion， and ATP in myocardial tissue were detected according to kit instructions. The mRNA and protein levels of SIRT1， PGC-1α， ERRα， and mitochondrial transcription factor A （TFAM） in myocardial tissue were determined by Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） and Western blot， respectively. ResultCompared with the sham operation group， the model group showed broken and disordered myocardial fibers， cytoplasmic edema， and pyknosis and deviation of nuclei. Moreover， the modeling increased the levels of CK-MB and LDH （P<0.05， P<0.01）， lowered the levels of ATP， CCO， and SDH （P<0.05， P<0.01）， and down-regulated the mRNA and protein levels of SIRT1， PGC-1α， ERRα， and TFAM in myocardial tissue （P<0.05， P<0.01）. Compared with the model group， Wenxin prescription reduced the myocardial infarction area （especially in the high-dose group， P<0.01）， restored the pathological changes， lowered the levels of CK-MB and LDH （P<0.05， P<0.01）， increased the levels of ATP， CCO， and SDH （especially in the high-dose group， P<0.01）， and up-regulated the mRNA and protein levels of SIRT1， PGC-1α， ERRα， and TFAM in myocardial tissue （P<0.05， P<0.01）. ConclusionWenxin prescription can protect rats from myocardial ischemia-reperfusion injury by regulating myocardial mitochondrial energy metabolism via the SIRT1/PGC-1α/ERRα signaling pathway.