ABSTRACT
ObjectiveTo observe the effects of the South African herb Hoodia gordonii （HG） on glucolipid metabolism in diabetic db/db mice and explore the possible mechanisms of HG on the liver of db/db mice based on the phosphoinositide-3 kinase （PI3K）/protein kinase B （Akt）/factor forkhead protein O1 （FoxO1） signaling pathway. MethodA total of 30 db/db mice were randomly divided into five groups according to fasting blood glucose： model group， metformin group （0.195 g·kg-1）， and low dose （0.39 g·kg-1）， medium dose （0.78 g·kg-1）， and high dose （1.56 g·kg-1） HG groups， with six m/m mice in each group， and another six m/m mice were set as normal group. The mice in the normal and model groups were given saline of 9 mL·kg-1 by gavage. Body weight， water intake， and fasting blood glucose of the mice in each group were measured weekly. After six weeks of continuous administration， serum insulin （FINS）， low-density lipoprotein cholesterol （LDL）， total cholesterol （TC）， triglyceride （TG）， alanine aminotransferase （ALT）， aspartate aminotransferase （AST）， urea， and creatinine （CREA） were measured， and liver sections were embedded and stained with hematoxylin-eosin （HE）， periodic acid-Schiff （PAS）， and oil red O. Protein expression of PI3K p85， p-Akt， and p-FoxO1 in liver was detected by immunohistochemistry. The mRNA expression of PI3K， Akt， and FoxO1 in liver tissue was detected by real-time polymerase chain reaction （Real-time PCR）. ResultAfter six weeks of administration intervention， it was found that fasting blood glucose was significantly downregulated in mice in the three HG groups （P<0.05）. The level of islet resistance index was significantly reduced in both the low and medium dose HG groups （P<0.05）. The expression levels of TC， TG， and LDL were reduced in all HG groups （P<0.05， P<0.01）. Pathologically， HG could alleviate hepatocyte steatosis， reduce the volume and content of lipid droplets in liver， and increase the distribution of glycogen granules in liver to some extent in mice. Immunohistochemical assays revealed that PI3K p85 protein expression was significantly increased in the low， medium， and high dose HG groups compared with the model group （P<0.01）. p-Akt protein expression was significantly increased in the medium and high dose HG groups （P<0.05， P<0.01）. p-FoxO1 protein expression was significantly increased in the low， medium， and high dose HG groups （P<0.05， P<0.01）. Compared with the model group， PI3K mRNA was increased in low dose， medium dose， and high dose HG groups （P<0.05）， and Akt mRNA was increased in high dose HG group （P<0.05）. FoxO1 mRNA was decreased in low dose， medium dose， and high dose HG groups （P<0.05）. ConclusionHG can ameliorate the disorder of glucolipid metabolism in db/db mice， which may be related to its activation of the hepatic PI3K/Akt/FoxO1 signaling pathway.
ABSTRACT
Diabetic kidney disease （DKD）， a major microvascular complication of diabetes mellitus， serves as the most common cause of end-stage renal disease worldwide. The progression of DKD is closely related to oxidative stress， inflammatory response， apoptosis， and fibrosis in renal tissues activated by high glucose. Numerous studies have shown that the transduction of the p38 mitogen-activated protein kinase （p38 MAPK） signaling pathway is involved in the pathological process of DKD in renal tissues， activating various pathological mechanisms， such as oxidation， inflammation， apoptosis， and fibrosis. Therefore， blocking the transduction of the p38 MAPK signaling pathway is beneficial to alleviating DKD. At present， the main treatment principles of western medicine are glucose lowering， lipid lowering， and blood pressure lowering， as well as medications with new drugs renal sodium-glucose co-transporter 2 （SGLT2）， mineralocorticoid receptor， and endothelin receptor， but the progression of DKD still cannot be stopped. The treatment of DKD by traditional Chinese medicine （TCM） has the advantages of simplicity， low cost， and convenience， and the symptoms and root causes can be both treated. In recent years， the basic research on Chinese medicine intervention in DKD has greatly advanced， and p38 MAPK is the key factor of Chinese medicine intervention in DKD. The present study searched and reviewed the literature on the Chinese medicine intervention in the p38 MAPK signaling pathway in DKD treatment in the past decade. The results showed that p38 MAPK interacted with transforming growth factor-β1 （TGF-β1）， cysteinyl aspartate-specific protease-3 （Caspase-3）， nuclear factor-κB （NF-κB）， and other factors to activate fibrosis， inflammation， oxidative stress， and apoptosis. By acting on p38 MAPK and its upstream and downstream factors， Chinese medicine blocked the pathological processes of DKD and inhibited the pathological injury of DKD and the deterioration of renal function. This study is expected to provide new ideas and directions for the prevention and treatment of DKD with Chinese medicine.
ABSTRACT
Diabetic peripheral neuropathy （DPN） is a symptom and/or sign of peripheral nerve dysfunction that occurs in patients with diabetes mellitus when other causes are excluded. DPN， one of the most common complications of diabetes mellitus， can lead to disability， foot ulcers， and amputation at a later stage. Its pathogenesis is closely related to high glucose-induced inflammatory damage， oxidative stress， mitochondrial disorders， and apoptosis in neural tissues. The p38 mitogen-activated protein kinase （p38 MAPK） signaling pathway is a key mechanism mediating the expression of inflammatory factors， oxidative factors， and apoptotic factors of neural tissues in DPN. The inflammatory response， oxidative stress damage， and apoptosis， induced by the activation of p38 MAPK phosphorylation by factors such as high glucose， can cause cell lipid peroxidation， protein modification， and nucleic acid damage， which results in axonal degeneration and demyelination changes. The current treatment of DPN with western medicine has obvious shortcomings such as adverse effects and addictive tendencies. In recent years， the research on traditional Chinese medicine （TCM） in the prevention and treatment of DPN has gradually increased， and the exploration of Chinese medicine intervention in the p38 MAPK pathway transduction to improve DPN has advanced. The present study reviewed the relations of the p38 MAPK pathway with insulin resistance and peripheral neuropathy and summarized the molecular biological mechanisms involved in the pathological process of DPN， such as inflammation regulation， oxidative stress， polyol pathway regulation， and Schwann cell apoptosis in the past 10 years. In addition， the literature on Chinese medicine monomers， Chinese patent medicines， and Chinese medicine compounds in inhibiting inflammatory reactions， oxidative injury， and apoptosis of DPN peripheral nerves based on the p38 MAPK pathway， resisting axonal degeneration and demyelination changes， improving sensory and motor abnormalities， relieving peripheral pain sensitization， and facilitating nerve conduction mechanism to provide references for the development of new drugs for clinical prevention and treatment of DPN.
ABSTRACT
ObjectiveTo explore the effect of Tangbikang granules （TBK） on sciatic nerve inflammation in diabetic rats through modulation of adenosine monophosphate-activated protein kinase （AMPK）/nuclear factor （NF）-κB pathway. MethodSD rats were fed with high-fat and high-sugar diet for 8 weeks and then treated with streptozotocin （STZ， ip） at 35 mg·kg-1 for modeling. Then the rats were randomized into diabetes group， low-dose （0.625 g·kg-1）， medium-dose （1.25 g·kg-1）， and high-dose （2.5 g·kg-1） TBK groups， and lipoic acid group （0.026 8 g·kg-1） according to body weight and blood glucose level， and a normal group was designed. After modeling， administration began and lasted 12 weeks. The body mass， blood glucose level， and thermal withdrawal latency （TWL） of the rats were detected before treatment and at the 4th， 8th， and 12th week of administration. At the 12th week， the sciatic nerve was collected for hematoxylin-eosin （HE） and Luxol fast blue （LFB） staining， and the structural changes of sciatic nerve were observed under scanning electron microscope. The levels of interleukin-1β （IL-1β） and tumor necrosis factor-α （TNF-α） in sciatic nerve were measured by enzyme-linked immunosorbent assay （ELISA）， and the levels of AMPK， phosphorylated （p）-AMPK， and NF-κB proteins in the sciatic nerve were measured by Western blot. ResultThe blood glucose concentration and TWL in the model group were higher than those in the normal group at each time point （P<0.01）. The levels of IL-1β， TNF-α， and NF-κB protein in sciatic nerve in the model group were higher than those in the normal group （P<0.01）， and the p-AMPK/AMPK ratio was smaller than that in the normal group （P<0.01）. Compared with the model group， TBK of the three doses lowered the TWL （P<0.05， P<0.01） and the levels of IL-1β， TNF-α， and NF-κB protein in sciatic nerve of rats （P<0.05， P<0.01）， and high-dose and medium-dose TBK raised p-AMPK/AMPK （P<0.05， P<0.01）. The sciatic nerve fibers were orderly and compact with alleviation of demyelination in rats treated with TBK compared with those in the model group. ConclusionTBK improves the function of sciatic nerve and alleviates neuroinflammation in diabetic rats. The mechanism is the likelihood that it up-regulates the expression of AMPK in the AMPK/NF-κB pathway and inhibits the expression of downstream NF-κB， thereby alleviating the neuroinflammation caused by high levels of inflammatory factors such as IL-1β and TNF-α due to NF-κB activation.
ABSTRACT
ObjectiveTo explore the mechanism of Tangbikang granules （TBK） against diabetic peripheral neuropathy （DPN） based on network pharmacology and in-vivo experiment. MethodThe active components in medicinals of TBK and their target genes were searched from Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform （TCMSP）. The active components of the medicinals which are not included in TCMSP were searched from previous research. After the analysis of drug-likeness by SwissADME， the target genes of them were predicted with SwissTargetPrediction. DPN-related target genes were retrieved from GeneCards. The common targets of the disease and the prescription were the hub genes of TBK against DPN， which were uploaded to Metascape for Gene Ontology （GO） term enrichment and Kyoto Encyclopedia of Genes and Genomes （KEGG） pathway enrichment analysis. High-sugar and high-fat diet and low-dose streptozotocin （STZ， ip） were employed to induce diabetes in rats， and then the model rats were respectively treated with low-dose （0.625 g·kg-1）， medium-dose （1.25 g·kg-1）， and high-dose （2.5 g·kg-1） TBK for 12 weeks. Sensory nerve conduction velocity （SNCV） was evaluated. After hematoxylin and eosin （HE） staining， the sciatic nerve was observed under light microscope to examine the nerve damage. Real-time PCR was performed to detect the gene expression of adenosine monophosphate-activated protein kinase （AMPK） pathway-related targets in rat sciatic nerve， and Western blot to measure the protein expression of AMPK and phosphorylated （p）-AMPK in rat sciatic nerve. ResultThe main active components of TBK， such as quercetin， kaempferol， β-sitosterol， leech pteridine A， stigmasterol， and baicalein were screened out， mainly acting on interleukin-6 （IL-6）， tumor necrosis factor （TNF）， protein kinase B （Akt）， JUN， and HSP90AA1 and signaling pathways such as AMPK， nuclear factor-κB （NF-κB）， and Janus kinase/signal transducer and activator of transcription （JAK/STAT）. Molecular docking results showed that β-sitosterol and stigmasterol had high binding affinity with IL-6， TNF， JUN， and HSP90AA1. As for the animal experiment， compared with the normal group， model group had low SNCV of sciatic nerve （P<0.01）， disordered and loose myelinated nerve fibers with axonotmesis and demyelinization， low mRNA expression of AMPKα， AMPKβ， peroxisome proliferator-activated receptor γ coactivator-1α （PGC-1α）， Sirtuin 3 （SirT3）， mitochondrial transcription factor A （TFAM）， and low p-AMPK/AMPK ratio in sciatic nerve （P<0.05， P<0.01）. Compared with the model group， TBK of the three doses raised the SNCV （P<0.01）， restored nerve morphology and nerve compactness， and increased the mRNA expression of AMPKα， AMPKβ， PGC-1α， SirT3， and TFAM （P<0.05， P<0.01）. The ratio of p-AMPK/AMPK in the high-dose and medium-dose TBK groups was higher than that in the model group （P<0.01）， while the protein expression in the low-dose TBK group was insignificantly different from that in the model group. ConclusionTBK exerts therapeutic effect on DPN through multiple pathways and targets. The mechanism is that it activates and regulates AMPK/PGC-1α/SirT3 signaling， which lays a basis for further study of TBK in the treatment of DPN.
ABSTRACT
ObjectiveThis study aims to investigate the therapeutic effect of Tangbikang granules（TBK） on type 2 diabetes mellitus （T2DM） complicated with non-alcoholic fatty liver disease （NAFLD） and to elucidate the underlying mechanism. MethodT2DM and NAFLD were induced in ZDF rats， which were then respectively treated （ig） with low-dose （0.625 g·kg-1）， medium-dose （1.25 g·kg-1）， and high-dose （2.5 g·kg-1） TBK for 12 weeks. Fasting blood glucose （FBG） and body mass were recorded every 4 weeks during the treatment. One week before sampling， the feed intake of rats was detected， and after 12 h night fasting， oral glucose tolerance test （OGTT） was performed. The area under the curve （AUC） was used to evaluate glucose tolerance， and the homeostatic model assessment for insulin resistance （HOMA-IR） was calculated. Blood in abdominal aorta and liver were collected for determination of blood glucose and lipid metabolism indexes： Fasting serum insulin （FINS）， serum total cholesterol （TC）， triglyceride （TG）， low density lipoprotein cholesterol （LDL-C）， high density lipoprotein cholesterol （HDL-C）， and nonesterified fatty acids （NEFA）. The liver was weighed to calculate the liver index， and the liver tissue morphology was observed and analyzed based on hematoxylin-eosin （HE） staining and periodic acid-Schiff （PAS） staining. The protein levels of insulin receptor substrate （IRS）， phosphatidylinositol 3-kinase （PI3K）， protein kinase B （Akt） and phosphorylated IRS and Akt were detected by Western blotting. All data were analyzed by SPSS 20.0. ResultThe feed intake of the model group was higher than that in the normal group （P<0.01）， and the feed intake the administration groups was lower than that in the model group （P<0.05， P<0.01）. At the 8th and 12th week， the body mass in the model group was lower than that in the normal group （P<0.01）. Compared with the model group， TBK reduced FBG in a concentration-dependent manner. The blood glucose level in OGTT and AUC in the model group were higher/larger than those in the normal group （P<0.01）. The blood glucose value in OGTT was decreased in TBK groups and the metformin group compared with that in the model group， and AUC in the administration groups was significantly different from that in the model group （P<0.01）. The serum level of FINS and HOMA-IR in the model group were higher than those in the normal group （P<0.01）， and they were lower in the TBK groups than in the model group （P<0.01）. Serum levels of TG， TC， HDL-C， NEFA （P<0.05， P<0.01）， and LDL-C were higher in the model group than in the normal group. Serum levels of TG， TC， LDL-C， and NEFA in the TBK groups were lower than those in the model group， and the levels of TG， LDL-C， and NEFA in TBK groups were concentration-dependent （lowest levels in high-dose TBK group）. Compared with the model group， high-dose TBK significantly increased the level of HDL-C （P<0.05）. Liver index of the model group was higher than that in the normal group （P<0.01）. The liver index of the administration groups showed a decreasing trend with no significant difference from that in the model group. As for the HE staining result of liver， the model group had unclear structure of liver lobule， enlarged cells of different sizes， and obvious steatosis of hepatocytes. TBK of all doses alleviated liver injury， particularly the high dose. For the PAS staining， compared with the normal group， the model group demonstrated significant fat vacuoles and significant reduction in purplish red glycogen granules in the cytoplasm. The staining results of high- and medium-dose groups of TBK were more similar to the normal group. Western blot was used to detect the protein expression of liver tissue. The expression of PI3K protein， p-IRS1/IRS1， and p-Akt/Akt in the model group were lower than those in the normal group （P<0.01）， and they were higher in the high-dose TBK group than in the model group （P<0.01）. ConclusionTBK exerts therapeutic effect on T2DM combined with NAFLD in ZDF rats by activating the typical PI3K signaling pathway.
ABSTRACT
Diabetic nephropathy （DN）， the most feared microvascular complication of diabetes and one of the most common and serious complications of diabetes， is the major cause of end-stage renal disease worldwide， leading cause of morbidity and mortality in patients with diabetes， and the main non-communicable cause of death worldwide. There are many types of saponins， which are the main bioactive components of various Chinese medicinals. They have various pharmacological activities such as lowering blood glucose and blood lipids， improving insulin resistance， anti-inflammation， anti-oxidative stress， anti-tumor， and immune modulation. In recent years， it has been frequently verified that the saponins in Chinese medicinals have definite effect in regulating DN， showing multi-target， multi-pathway， multi-system， multi-effect characteristics. Thus， they have broad prospects in the prevention and treatment of this disease. There has been an explosion of research on the treatment of DN with saponins in Chinese medicinals in vivo and in vitro， but there is a lack of systematic and comprehensive summary. Therefore， this study summed up the studies of saponins in Chinese medicinals in the intervention of DN and summarized the mechanisms such as improving glucolipid metabolism， inhibiting oxidative stress， anti-inflammation， anti-apoptosis， regulating autophagy， anti-fibrosis， and protecting podocytes， with a view to providing ideas and references for the development of drugs related to DN.