Effect and Mechanism of Water Extract of Mori Folium on Oxidative Stress in Adipose Tissue of T2DM Mice / 中国实验方剂学杂志

ObjectiveTo observe the effect of water extract of Mori Folium （MLE） on oxidative stress in adipose tissue of type 2 diabetes mellitus （T2DM） mice and explore its mechanism. MethodTwenty-four male db/db mice were randomly divided into model group， metformin group， low-dose MLE （MLE-L） group， and high-dose MLE （MLE-H） group according to their body weight and blood glucose， with six mice in each group， and other six C57BLKS/JGpt wild littermate mice were selected as normal group. The mice in the metformin group were given 200 mg·kg-1 metformin suspension， and the mice in the MLE-L and MLE-H groups were respectively given 2 g·kg-1 and 4 g·kg-1 MLE， while the mice in the normal group and model group were given the same dose of deionized water by daily gavage for eight weeks. Body weight， subcutaneous fat index， fasting blood glucose （FBG）， and oral glucose tolerance level （OGTT） of the mice were detected， and serum superoxide dismutase （SOD）， glutathione peroxidase （GSH-Px）， and malondialdehyde （MDA） were measured. The expression levels of silent information regulator 1 （SIRT1） and NADPH oxidase type 4 （NOX4） protein in subcutaneous adipose tissue of the mice were detected by Western blot. ResultThe FBG level， OGTT， and subcutaneous fat index of T2DM mice were significantly decreased （P<0.05， P<0.01） after administration of MLE compared with the blank group. The contents of serum SOD and GSH were significantly increased， while the level of oxidative stress damage marker MDA was significantly decreased （P<0.05， P<0.01）. The expression of SIRT1 protein in adipose tissue was significantly increased， while the expression of NOX4 protein was significantly decreased （P<0.05， P<0.01）. ConclusionMLE can ameliorate T2DM by alleviating oxidative stress in adipose tissue of T2DM mice and reducing blood glucose.

Protective Effect and Mechanism of Mori Folium Extract on Kidney of db/db Diabetic Mice / 中国实验方剂学杂志

ObjectiveTo investigate the protective effects of Mori Folium extract （MLE） on the kidney of db/db diabetic mice and its mechanism. MethodTwenty-four male C57BLKS/JGpt-Leprdb/Leprdb （db/db） mice were randomly divided into model group， metformin group， low-dose group of MLE （MLE-L）， and high-dose group of MLE （MLE-H） according to their fasting blood glucose （FBG）， with six mice in each group， and other six C57BLKS/JGpt wild littermate （m/m） mice were selected as normal group. The mice in the drug administration groups were given corresponding drugs by gavage， and the mice in the normal group and model group were given the same dose of deionized water by gavage once a day for continuous eight weeks. Body weight， bilateral kidney weight， and FBG were measured， and an oral glucose tolerance test （OGTT） was performed. The pathological changes in the kidney tissue of mice were observed by hematoxylin-eosin （HE） and periodic acid-silver （PAS） staining， and serum creatinine （SCr） and blood urea nitrogen （BUN） levels were detected. Enzyme-linked immunosorbent assay （ELISA） was used to detect the levels of tumor necrosis factor-alpha （TNF-α） and interleukin-6 （IL-6） in serum and urinary microalbumin （U-mAlb） of mice. The expression levels of toll-like receptor 4 （TLR4）， myeloid differentiation factor 88 （MyD88）， and nuclear factor-kappa B p65 （NF-κB p65） protein in kidney tissue of mice were tested by Western blot. ResultCompared with the normal group， the body weight， absolute renal weight， FBG， and the area under the curve （AUC） of OGTT of mice in the model group were significantly increased （P<0.01）， and the levels of SCr， BUN， and U-mAlb， as well as TNF-α and IL-6 in serum were significantly increased （P<0.01）. The glomerular basement membrane in the kidney tissue of mice was thicker， with obvious inflammatory cell infiltration. The protein expression levels of TLR4， MyD88， and NF-κB p65 in the kidney tissue of mice were increased significantly （P<0.01）. Compared with the model group， there was no statistical difference in the body weight of mice in each drug administration group. The absolute renal weight of mice in the MLE-H and metformin groups was significantly reduced （P<0.05， P<0.01）. The FBG levels of mice in the metformin， MLE-L， and MLE-H groups started to decrease after treatment for four to eight weeks （P<0.05， P<0.01）. The AUC of mice in the MLE-H and metformin groups was significantly decreased （P<0.01）. The levels of SCr， BUN， and U-mAlb of mice in the MLE-H and metformin groups were significantly decreased （P<0.01）， and those of SCr and U-mAlb of mice in the MLE-L group were significantly decreased （P<0.01）. The levels of TNF-α and IL-6 in the serum of mice in the MLE-H and metformin groups were significantly decreased （P<0.01）. The renal tissue pathology of mice in each drug administration group was improved to varying degrees， and the protein expression levels of TLR4， MyD88， and NF-κB p65 in the MLE-H group were decreased significantly （P<0.05， P<0.01）. ConclusionMLE can improve the renal structure and function of db/db diabetic mice， and its mechanism may be related to the inhibition of the TLR4/MyD88/NF-κB signaling pathway.

Extraction Process and Mechanism of Active Ingredients of Mori Folium for Lowering Blood Glucose： A Review / 中国实验方剂学杂志

Mori Folium， the dried leaves of Morus alba， is widely used in clinical practice for dispersing wind and heat， clearing the lung and moistening dryness， soothing the liver and improving vision， and cooling blood and stopping bleeding. It has been used to regulate blood glucose since ancient times， and modern studies have shown that the active components of Mori Folium for lowering blood glucose mainly include flavonoids， alkaloids， polysaccharides， and phenols. These components are mainly extracted by solvents such as water and alcohols with the assistance of ultrasound and microwave. In addition， new extraction methods are emerging， such as CO2 supercritical fluid extraction， enzymatic hydrolysis， and cloud point extraction. Mori Folium lowers blood glucose via multiple components， pathways， and targets. Specifically， it can improve glucose and lipid metabolism， protect pancreatic β cells， and alleviate insulin resistance to reduce the damage caused by hyperglycemia and restore normal physiological functions. Although a large number of studies have been carried out on diabetes， the causes and radical treatment methods remain to be explored， and diabetes is still a major disease that endangers human health and needs to be solved urgently. The articles about extraction process and mechanism of active components in Mori Folium for lowering blood glucose were retrieved from the China National Knowledge Infrastructure （CNKI）， Web of Science， and PubMed. We analyzed the applicable extraction methods for the blood glucose-lowering components such as flavonoids， polysaccharides， and alkaloids in Mori Folium， and compared the conventional and emerging methods. Furthermore， we summarized our research achievements in the extraction of active components from Mori Folium and the blood glucose-lowering effect and mechanisms. This review aims to provide theoretical support for the optimization of the extraction process， the research on the blood glucose-lowering components and mechanism， and the development of new drugs and clinical application of Mori Folium.

Pathological Mechanism of Diabetes Based on NF-κB Signaling Pathway and Traditional Chinese Medicine Intervention： A Review / 中国实验方剂学杂志

As people's living standards improve， the development trend of diabetes has gradually become severe. Diabetes is a chronic inflammatory disease associated with abnormal expression of nuclear factor-kappa B （NF-κB） in patients. NF-κB exists in various tissue cells and participates in the regulation of a variety of genes related to immune function and inflammation. Varieties of factors can activate NF-κB when the body is stimulated by external factors， so as to produce inflammation and other reactions. Previous studies on NF-κB mainly focus on cancer， and the pathological mechanism of the treatment of diabetes by related signaling pathways and the progress of traditional Chinese medicine （TCM） treatment have not been systematically elaborated on. By referring to the relevant literature in China and abroad， it was found that NF-κB is not isolated in the development and progression of diabetes but is associated with signal molecules related to inflammation， oxidative stress， and energy metabolism， and it is involved in mediating inflammation， pancreatic β cell apoptosis， insulin signal transduction， and other physiological functions. Therefore， blocking the transmission of NF-κB signaling pathway is beneficial to the treatment of diabetes. At present， Western medicine for the treatment of diabetes mainly includes oral hypoglycemic drugs and insulin injections， but the adverse reactions are obvious. TCM has been characterized by multi-target， extensive action， and excellent curative effects in the treatment of diabetes. TCM and its compounds with functions of tonifying Qi and promoting blood circulation， regulating qi and eliminating phlegm， clearing heat and detoxifying， and nourishing Yin and moistening dryness can effectively intervene in the abnormal expression of NF-κB signaling pathway in vivo through anti-inflammatory effects. In this paper， the association between NF-κB signaling pathway and diabetes was summarized， and the modern research progress of TCM intervention of NF-κB signaling pathway in the treatment of diabetes in the past five years was reviewed， so as to lay a laboratory foundation for the study of a new pathological mechanism of diabetes based on NF-κB signaling pathway and provide new targets and research direction for the prevention and treatment of diabetes and development of related TCM.

Mulberry leaf flavonoids activate BAT and induce browning of WAT to improve type 2 diabetes via regulating the AMPK/SIRT1/PGC-1α signaling pathway / 中国天然药物

Mulberry (Morus alba L.) leaf is a well-established traditional Chinese botanical and culinary resource. It has found widespread application in the management of diabetes. The bioactive constituents of mulberry leaf, specifically mulberry leaf flavonoids (MLFs), exhibit pronounced potential in the amelioration of type 2 diabetes (T2D). This potential is attributed to their ability to safeguard pancreatic β cells, enhance insulin resistance, and inhibit α-glucosidase activity. Our antecedent research findings underscore the substantial therapeutic efficacy of MLFs in treating T2D. However, the precise mechanistic underpinnings of MLF's anti-T2D effects remain the subject of inquiry. Activation of brown/beige adipocytes is a novel and promising strategy for T2D treatment. In the present study, our primary objective was to elucidate the impact of MLFs on adipose tissue browning in db/db mice and 3T3-L1 cells and elucidate its underlying mechanism. The results manifested that MLFs reduced body weight and food intake, alleviated hepatic steatosis, improved insulin sensitivity, and increased lipolysis and thermogenesis in db/db mice. Moreover, MLFs activated brown adipose tissue (BAT) and induced the browning of inguinal white adipose tissue (IWAT) and 3T3-L1 adipocytes by increasing the expressions of brown adipocyte marker genes and proteins such as uncoupling protein 1 (UCP1) and beige adipocyte marker genes such as transmembrane protein 26 (Tmem26), thereby promoting mitochondrial biogenesis. Mechanistically, MLFs facilitated the activation of BAT and the induction of WAT browning to ameliorate T2D primarily through the activation of AMP-activated protein kinase (AMPK)/sirtuin 1 (SIRT1)/peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC-1α) signaling pathway. These findings highlight the unique capacity of MLF to counteract T2D by enhancing BAT activation and inducing browning of IWAT, thereby ameliorating glucose and lipid metabolism disorders. As such, MLFs emerge as a prospective and innovative browning agent for the treatment of T2D.

Rutin Promotes Browning of 3T3-L1 Preadipocytes and Its Mechanism / 中国实验方剂学杂志

ObjectiveTo investigate the effect of rutin on the browning of 3T3-L1 preadipocytes and the mechanism. MethodCell counting kit-8 （CCK-8） assay was used to detect the effect of different concentration of rutin （3.125， 6.25， 12.5， 25， 50， 100， 200 μmol·L-1） on 3T3-L1 cell activity， and Western blot to examine the effect of rutin （12.5， 25， 50 μmol·L-1） on the expression of thermogenesis-associated proteins uncoupling protein 1 （UCP1）， PR domain containing 16 （PRDM16） and peroxisome proliferator-activated receptor γ coactivator-1α （PGC-1α） in adipocytes. After the optimal concentration of rutin was determined， the effect of rutin on lipid droplet formation in adipocytes was observed based on oil red O staining， and the expression of nuclear respiratory factor 1 （NRF1）， nuclear respiratory factor 2 （NRF2） and mitochondrial transcription factor A （TFAM）， which were the landmark proteins of mitochondrial biosynthesis， was detected by Western blot. ResultCompared with the blank group， 200 μmol·L-1 rutin inhibited 3T3-L1 cell activity （P<0.01）. Compared with the blank group， at the concentration of 12.5， 25， 50 μmol·L-1 rutin significantly promoted the expression of thermogenesis-associated proteins （UCP1， PRDM16， and PGC-1α） （P<0.01）， which was determined as the optimal concentration. Compared with the blank group， 50 μmol·L-1 rutin significantly increased the immunofluorescence intensity of mitochondrial UCP1 protein in 3T3-L1 cells （P<0.01） and the expression of the markers of mitochondrial biosynthesis （NRF1， NRF2， and TFAM） （P<0.01）. In addition， 50 μmol·L-1 rutin significantly inhibited lipid droplet formation of 3T3-L1 adipocytes （P<0.01）. ConclusionRutin inhibited lipid droplet deposition in 3T3-L1 adipocytes and increased the expression of thermogenesis-related proteins （UCP1， PRDM16， and PGC-1α） and markers of mitochondrial biosynthesis （NRF1， NRF2， and TFAM）， thereby inducing the browning of 3T3-L1 adipocytes. This lays a basis for the development of drugs that safely regulate the browning of white cells.

Total Flavonoids of Mulberry Leaves Improves Liver Lipid Metabolism in Type 2 Diabetic Rats by Regulating PPAR-α/CPT-1 Pathway / 中国实验方剂学杂志

ObjectiveTo investigate the medicinal effect of total flavonoids of mulberry leaves on regulating liver lipid metabolism disorder in diabetes mellitus type 2 （T2DM） rats， and the mechanism based on liver peroxidase proliferators activate receptors-α （PPAR-α） and carnitine palmityl transferase-1 （CPT-1） proteins. MethodTotal flavonoids of mulberry leaves were extracted and purified by ethanol extraction + macroporous resin purification and then identified. T2DM rat model was induced by high fat diet （HFD） + streptozocin（STZ）method. Rats with blood glucose ≥ 11.1 mmol·L-1 were divided into three administration groups with the high dose （300 mg·kg-1）， medium dose （150 mg·kg-1）， and low dose （75 mg·kg-1） of total flavonoids of mulberry leaves for 8 weeks， respectively， to observe the weight and blood glucose of the rats. The pathological changes of rat livers were observed by hematoxylin-eosin （HE） staining. Biochemical method was used to detect the levels of total cholesterol （TC）， triglyceride （TG）， low density lipoprotein-cholesterol （LDL-C）， and high density lipoprotein-cholesterol （HDL-C） of blood lipid metabolism in rats. The messenger ribonucleic acid （mRNA） and protein expressions of PPAR-α and CPT-1 were determined by real-time quantitative polymerase chain reaction （Real-time PCR） and Western blot. ResultAfter 8 weeks of intervention of total flavonoids of mulberry leaves， compared with the control group， the food intake， liver index， and fasting blood glucose of rats in the model group increased significantly （P<0.01）. Compared with the model group， the food intake， fasting blood glucose， and liver index of rats in the administration groups decreased significantly （P<0.01）. The results of HE staining showed that the liver tissue structure of rats in the control group was complete and there was no obvious abnormality. The model group showed vacuolar degeneration and inflammatory infiltration of hepatocytes of rats. There was no obvious abnormality in the liver structure of rats in the administration groups. The results of blood lipid showed that compared with the control group， the levels of TC， TG， and LDL-C increased significantly （P<0.01）， but the level of HDL-C decreased significantly （P<0.01） in the model group. Compared with the model group， the levels of TC， TG， and LDL-C decreased significantly （P<0.05， P<0.01）， whereas the level of HDL-C increased significantly （P<0.01） in the administration groups. The results of Real-time PCR showed that compared with the control group， the mRNA expression of PPAR-α and CPT-1 of rats in the model group decreased significantly （P<0.01）. Compared with the model group， the mRNA expressions of PPAR-α and CPT-1 of rats in the high-dose group increased significantly （P<0.01）. The results of Western blot showed that compared with the control group， the protein expressions of PPAR-α and CPT-1 of rats in the model group decreased significantly （P<0.01）. Compared with the model group， the protein expressions of PPAR-α and CPT-1 of rats in the high-dose group increased significantly （P<0.05， P<0.01）. ConclusionTotal flavonoids of mulberry leaves can effectively reduce blood glucose and improve liver lipid metabolism disorder in T2DM rats. The total flavonoids of mulberry leaves could regulate lipid metabolism and play a hypoglycemic role by activating and regulating PPAR-α and CPT-1 proteins and promoting oxidative decomposition of fatty acids.

TGF-β-related Signaling Pathways in Pathogenesis of Diabetes and Prospect of Chinese Medicine Intervention： A Review / 中国实验方剂学杂志

The incidence of diabetes has been on the rise as the result of lifestyle changes， especially the high-fat diet and reduced exercise. Thus， it has become a global public health problem and it is an urgent task to explore effective therapy. There has been an explosion of research on the relationship of transforming growth factor-β （TGF-β） signaling pathways with diabetes complications and tumors， but the role of the pathways in the occurrence and progression of diabetes remains unclear. TGF-β signaling pathways can be activated by many factors， directly or indirectly leading to the apoptosis of islet β cells and insulin resistance （IR）， and thus they are expected to become new targets for the treatment of diabetes. TGF-β-related signaling pathways involve AMP-activated proteinkinase （AMPK）， protooncogene （c-Myc）， Ski-relatednovel protein N （SnoN）， Smad ubiquitination regulatory factor 1 （Smurf1）， miR-335-5p， and other signaling molecules. They participate in the occurrence and development of IR， apoptosis of islet β cells， insulin secretion disorder， fibrosis of adipocytes， and metabolic disorder of adipocytes， and inhibit the browning of white adipose tissue， playing an important part in the pathological process of human diabetes. According to traditional Chinese medicine （TCM）， the pathogenesis of diabetes is the deficiency of Qi and Yin， and the late stage is characterized by the syndrome of Qi deficiency， and Yang deficiency and blood stasis， which should be treated according to the principle of replenishing Qi and nourishing Yin， warming Yang and activating blood. It has been found that the efficacy of some Chinese medicinals and compound prescriptions on diabetes is closely related to the TGF-β signaling pathways. This paper reviews TGF-β-associated signaling pathways， elucidating the roles of them in pathogenesis of diabetes， and analyzes the relationship of TGF-β-associated signaling pathways with the effect of compound Chinese medicine prescriptions against diabetes. This study is expected to lay a theoretical basis for the research on the treatment diabetes.