Evaluation of hypoglycemic efficacy of tangningtongluo formula, a traditional Chinese Miao medicine, in two rodent animal models

Study on the therapeutic effect and mechanism of Tangningtongluo Tablet on diabetic mice

AIMS

To investigate the therapeutic effects of Tangningtongluo Tablet on diabetic mice and its mechanism. This study was established the scientific basis for the clinical application of Tangningtongluo Tablet in the treatment of diabetes mellitus and provided data supporting the transformation of Tangningtongluo Tablet from an in-hospital preparation to a new Chinese medicine.

METHODS

In this study, a diabetic mouse model was established by high-glucose and high-fat diet feeding in combination with STZ injection for 4 weeks. Glucose metabolism, lipid metabolism, liver histomorphological changes and liver function related indexes were detected, pancreatic histomorphological changes and insulin resistance related indexes were observed, and the expression of pathway related proteins and inflammatory factors were examined.

RESULTS

Glycemia and glycated hemoglobin were reduced in diabetic mice after the treatment of Tangningtongluo Tablet, and glucose tolerance and lipid results were modified. The insulin resistance status of the mice was diminished and tissue damage to the pancreas and liver was repaired. Expression of ERS/NF-κB related pathway proteins was reduced in liver tissues, and inflammatory factors such as TNF-α, IL-6 and IL-1β were reduced in serum.

CONCLUSIONS

Tangningtongluo Tablet could reduce blood glucose in diabetic mice, regulate the disorder of lipid metabolism, enhance insulin sensitivity, improve insulin resistance, repair pancreatic tissue damage and protect mouse liver in diabetic mice. The mechanism of action might be related to the regulation of ERS/NF-κB signaling pathway and the reduction of TNF-α, IL-6 and IL-1β production.

Tetramethylpyrazine Attenuates Cognitive Impairment Via Suppressing Oxidative Stress, Neuroinflammation, and Apoptosis in Type 2 Diabetic Rats

Cognitive dysfunction is an important complication observed in type 2 diabetes mellitus (T2DM) patients. Tetramethylpyrazine (TMP) is known to exhibit anti-diabetic and neuroprotective properties. Therefore, the present study aimed to investigate the possible therapeutic effects of TMP against type 2 diabetes-associated cognitive impairment in rats. High-fat diet (HFD) followed by a low dose of streptozotocin (35 mg/kg) was used to induce diabetes in Sprague-Dawley rats. TMP (20, 40, and 80 mg/kg) and Pioglitazone (10 mg/kg) were administered for 4 weeks. The Morris water maze (MWM) and novel objective recognition task (NOR) tests were used to assess memory function. Fasting blood glucose (FBG), lipid profile, HOMA-IR, glycosylated hemoglobin (HbA1c), and glucose tolerance were measured. Acetylcholinesterase (AChE) and choline acetytransferase (ChAT) activity, acetylcholine (ACh) levels, oxidative stress, apoptotic (Bcl-2, Bax, caspase-3), and inflammatory markers (TNF-α, IL-1β, and NF-kβ) were assessed. BDNF, p-AKT, and p-CREB levels were also measured. In the present work, we observed that treatment of diabetic rats with TMP alleviated learning and memory deficits, improved insulin sensitivity, and attenuated hyperglycemia and dyslipidemia. Furthermore, treatment with TMP increased BDNF, p-Akt, and p-CREB levels, normalized cholinergic dysfunction, and suppressed oxidative, inflammatory, and apoptotic markers in the hippocampus. Collectively, our results suggest that the TMP may be an effective neuroprotective agent in alleviating type 2 diabetes-associated cognitive deficits.

Emerging Applications of Metabolomics to Assess the Efficacy of Traditional Chinese Medicines for Treating Type 2 Diabetes Mellitus

Diabetes is a common and complex disease that can exacerbate the complications related to cardiovascular disease, and this is especially true for type 2 diabetes mellitus (T2DM). In addition to the standard pharmacological therapies, T2DM has also been treated with nonconventional regimens such as traditional Chinese medicine (TCM), e.g., herbal medicines and TCM prescriptions, although the mechanisms underlying the therapeutic benefits remain unclear. In this regard, many studies have used metabolomics technology to elucidate the basis for the efficacy of TCM for T2DM. Metabolomics has recently attracted much attention with regard to drug discovery and pharmacologically relevant natural products. In this review, we summarize the application of metabolomics to the assessment of TCM efficacy for treating T2DM. Increasing evidence suggests that the metabolic profile of an individual patient may reflect a specific type of T2DM syndrome, which may provide a new perspective for disease diagnosis. In addition, TCM has proved effective for countering the metabolic disorders related to T2DM, and this may constitute the basis for TCM efficacy. Therefore, further determining how TCM contributes to the reversal of metabolic disorders, such as using network pharmacology or by assessing the contribution of host–gut microbiota interactions, will also provide researchers with new potential targets for pharmacologic-based therapies.

An innovative method for screening and evaluating the degree of diabetic retinopathy and drug treatment based on artificial intelligence algorithms

Current methods of evaluating the degree of diabetic retinopathy are highly subjective and have no quantitative standard. To objectively evaluate the slight changes in tissue structure during the early stage of retinal diseases, a subjective interpretation and qualitative analysis of the pathological sections of retinal HE in diabetic animals is required for screening and evaluating the degree of diabetic retinopathy and drug efficacy. To develop an innovative method for screening and evaluating the degree of diabetic retinopathy and drug treatment based on artificial intelligence algorithms. Based on the change law of the early nerve fiber layer and the ganglion cells, we get disparate characteristics of the microscopic image of diabetes animal retina HE slices. Using image recognition and deep learning methods on these HE slices, we can identify the changes in the ganglion cells and nerve fiber layer for diagnosing early retinopathy and evaluated the therapeutic effect of the potential drugs. We conduct quantitative calculation per unit length of the nerve fiber layer and total area of the nerve fiber layer to identify biology significance of edema. Additionally, we also perform quantitative calculation with the number of unit area ganglion cells to identify the section in biology cell hyperplasia. Finally, we get the significance of quantitative calculation on the unit cell area to identify ganglion cell shriveling in biology. In addition to the evaluation of the disease degree and changes, we also obtained retinal HE sections after different drug interventions and evaluated the therapeutic effect of the drugs. This study presents a novel quantitative method for screening and evaluating of diabetic retinopathy and drug efficacy.

OMICs approaches-assisted identification of macrophages-derived MIP-1γ as the therapeutic target of botanical products TNTL in diabetic retinopathy

Background

Inflammatory reaction in the dysfunction of retinal endotheliocytes has been considered to play a vital role in diabetic retinopathy (DR). Anti-inflammatory therapy so far gains poor outcome as DR treatment. This study aims to identify a novel therapeutic target of DR from the OMICs studies of a traditional anti-DR botanical products TNTL.

Methods

Hyperglycemic mice were treated with TNTL. The anti-hyperglycemic effect of TNTL was validated to confirm the biological consistency of the herbal products from batches. Improvement of DR by TNTL was examined by various assays on the retina. Next-generation transcriptome sequencing and cytokine array was used to identify the therapeutic targets. In vitro study was performed to validate the target.

Results

We observed that TNTL at its high doses possessed anti-hyperglycemic effect in murine type I diabetic model, while at its doses without reducing blood glucose, it suppressed DR incidence. TNTL restored the blood-retina barrier integrity, suppressed retinal neovascularization, and attenuated the retinal ganglion cell degeneration. Transcriptomic analysis on the retina tissue of hyperglycemic mice with or without TNTL revealed that the inflammatory retina microenvironment was significantly repressed. TNTL treatment suppressed pro-inflammatory macrophages in the retina, which resulted in the inactivation of endothelial cell migration, restoration of endothelial cell monolayer integrity, and prevention of leakage. Cytokine array analysis suggested that TNTL could significantly inhibit the secretion of MIP1γ from pro-inflammatory macrophages. Prevention of endothelial dysfunction by TNTL may be mediated by the inhibition of MIP1γ/CCR1 axis. More specifically, TNTL suppressed MIP1γ release from pro-inflammatory macrophages, which in turn inhibited the activation of CCR1-associated signaling pathways in endothelial cells.

Conclusion

Our findings demonstrated that TNTL might be an alternative treatment to DR, and the primary source of potential drug candidates against DR targeting MIP1γ/CCR1 axis in the retinal microenvironment.

The Chinese herbal formulae (Yitangkang) exerts an antidiabetic effect through the regulation of substance metabolism and energy metabolism in type 2 diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Type 2 diabetes mellitus (T2DM) regarded as a "hot" disease in traditional Chinese medicine (TCM). Accordingly, TCM uses a cold drug or formula such as the Chinese herbal formulae "Yitangkang" (YTK) as a treatment. YTK exhibited a good clinical antidiabetic effect in several experiments. The correlation between the properties of a TCM drug or formula and its ability to regulate the substance metabolism, the energy metabolism and the endocrine system has been proven.

AIM OF THE STUDY

The present study aiming to evaluate the mechanism of antidiabetic action of YTK from the above perspective.

MATERIALS AND METHODS

Three groups of streptozotocin (STZ)-diabetic rats have been treated with YTK at oral doses of 56 g/kg/d, 28 g/kg/d and 14 g/kg/d for 28 days using metformin as a reference drug. After treatment, several indices correlated with energy metabolism (superoxide dismutase, glutathione peroxidase, lactic dehydrogenase, adenotriphos, creatine phosphate kinase, AMPK, Na⁺-K⁺-ATPase and Respiratory Chain Complex I, II, III, IV), substance metabolism (hepatic glycogen, acetyl-coenzyme A, pyruvic acid, adipose triglyceride lipase, triglycerides, high-density lipoproteins, low-density lipoproteins, malonyldialdehyde), endocrine system (triiodothyronine, thyroxine, 17-hydroxycorticosteroid) and cyclic nucleotide system (cyclic adenosine monophosphate, cyclic guanosine monophosphate) have been determined. The specialty and tendency of YTK's effects were analyzed to elucidate its property and mechanism of action according to the theory of TCM.

RESULTS

Our findings showed that the formulae YTK could effectively regulate the levels of blood glucose, HbA1c, glucagon-like peptide-1, and significantly down-regulate the substance metabolism, energy metabolism and endocrine system indices of the diabetic rats.

CONCLUSION

These results were consistent with the TCM description of YTK as a "cold" treatment. It could provide an effective way to interpret the scientific connotation and comprehensive system of the Chinese herbal formulae.

The Efficacy and Mechanism of Chinese Herbal Medicine on Diabetic Kidney Disease

Diabetic kidney disease (DKD) is the most common microvascular complication of diabetes and is one of the main causes of end-stage renal disease (ESRD) in many countries. The pathological features of DKD are the hypertrophy of mesangial cells, apoptosis of podocytes, glomerular basement membrane (GBM) thickening, accumulation of extracellular matrix (ECM), glomerular sclerosis, and tubulointerstitial fibrosis. The etiology of DKD is very complicated and many factors are involved, such as genetic factors, hyperglycemia, hypertension, hyperlipidemia, abnormalities of renal hemodynamics, and metabolism of vasoactive substances. Although some achievements have been made in the exploration of the pathogenesis of DKD, the currently available clinical treatment methods are still not completely effective in preventing the progress of DKD to ESRD. CHM composed of natural products has traditionally been used for symptom relief, which may offer new insights into therapeutic development of DKD. We will summarize the progress of Chinese herbal medicine (CHM) in the treatment of DKD from two aspects. In clinical trials, the Chinese herbal formulas were efficacy and safety confirmed by the randomized controlled trials. In terms of experimental research, studies provided evidence for the efficacy of CHM from the perspectives of balancing metabolic disorders, reducing inflammatory response and oxidative stress, antifibrosis, protecting renal innate cells, and regulating microRNA and metabolism. CHM consisting of different ingredients may play a role in synergistic interactions and multiple target points in the treatment of DKD.

Rapamycin improves insulin resistance and hepatic steatosis in type 2 diabetes rats through activation of autophagy

Insulin resistance (IR) is a hallmark of type 2 diabetes mellitus (T2DM). This study aimed to explore the effects of rapamycin, a specific inhibitor of kinase mammalian target of rapamycin (mTOR), on IR in T2DM rats, and to validate whether the underlying mechanism was associated with autophagy. In this study, the model of T2DM rats was established by feeding the animals with a high-fat diet (HFD) and intraperitoneal injection of streptozotocin (STZ). Diabetic rats were randomly divided into model of T2DM control group (DM-C, n = 15), metformin group (DM-M, n = 15), rapamycin group (DM-Rapa, n = 15), 3-methyladenine (3-MA) group (DM-3-MA, n = 15), and rapamycin + 3-MA group (DM-Rapa-3-MA, n = 15). Rats in different treatment groups were given by corresponding therapy from gastric tube. Meanwhile, normal control group was established (n = 10). As expected, HFD- and STZ- induced T2DM rats exhibited significantly impaired glucose tolerance, reduced insulin sensitivity, dysglycemia and dyslipidemia, aggravated hepatic steatosis, enhanced hepatic inflammation, elevated p-mTOR, and suppressed hepatic autophagy. Importantly, rapamycin and metformin significantly ameliorated IR, relieved disorders of glucose and lipid metabolism, reduced inflammatory level, inhibited mTOR, and promoted autophagy. Importantly, the autophagy inhibitor 3-MA significantly reversed the effects exerted by rapamycin. Collectively, our study suggests that rapamycin improved IR and hepatic steatosis in T2DM rats via activation of autophagy.

TERT and Akt Are Involved in the Par-4-Dependent Apoptosis of Islet β Cells in Type 2 Diabetes

Islet β cell apoptosis plays an important role in type 2 diabetes. We previously reported that Par-4-mediated islet β cell apoptosis is induced by high-glucose/fatty acid levels. In the present study, we show that Par-4, which is induced by high-glucose/fatty acid levels, interacts with and inhibits TERT in the cytoplasm and then translocates to the nucleus. Par-4 also inhibited Akt phosphorylation, leading to islet β cell apoptosis. We inhibited Par-4 in islet β cells under high-glucose/fatty acid conditions and knocked out Par-4 in diabetic mice, which led to the up-regulation of TERT and an improvement in the apoptosis rate. We inhibited Akt phosphorylation in islet β cells and diabetic mice, which led to aggressive apoptosis. In addition, the biological film interference technique revealed that Par-4 bound to TERT via its NLS and leucine zipper domains. Our research suggests that Par-4 activation and binding to TERT are key steps required for inducing the apoptosis of islet β cells under high-glucose/fatty acid conditions. Inhibiting Akt phosphorylation aggravated apoptosis by activating Par-4 and inhibiting TERT, and Par-4 inhibition may be an attractive target for the treatment of islet β cell apoptosis.

Effects of the Tangningtongluo formula as an alternative strategy for diabetics via upregulation of insulin receptor substrate-1

Tangningtongluo (TNTL), a traditional Chinese medicine, has been widely used in clinics for decades in southwest China. Its pharmacological properties and underlying molecular mechanisms remain unclear. The main goal of ethnopharmacology is to identify novel bioactive compounds derived from plants for use in indigenous medical practice. This knowledge can be used to develop novel pharmaceuticals. In the present study, hyperglycemic C57BL/KsJ-db/db (db/db) mice were used to test the effect of TNTL on microvasculature of the retina and hypoglycemia. Metformin (Met) was selected as a positive control. 26-week-old mice were randomly assigned to receive either the anti-diabetic agent Met [140 mg/kg body weight (BW)], 1.8, 0.9 or 0.45 g/kg BW TNTL, or a placebo. The fasting blood glucose, serum insulin and glycated hemoglobin levels were measured. Histopathologic examination of the pancreas was performed to confirm the hypoglycemic effect. Fluorescein angiography was applied to detect diabetes-induced retinal angioma in the db/db mice. TNTL intake significantly decreased the fasting blood glucose level in a dose-dependent manner. Additionally, TNTL intervention resulted in a significant decrease in the insulin resistance index. Notably, TNTL treatment markedly reduced the speed of retinal degeneration and mildly reversed microvascular caliber degeneration. Western blot analysis indicated that upregulation of phosphorylated insulin receptor substrate-1 (p-IRS-1) by the administration of TNTL may be strongly involved in the improvement of insulin resistance. In conclusion, TNTL exerted a strong hypoglycemic effect and reversed retinal degeneration via upregulation of ISR-1. The present findings provide important scientific evidence supporting TNTL as an effective alternative approach for the management of Type 2 diabetes mellitus.

Recent Update on the Role of Chinese Material Medica and Formulations in Diabetic Retinopathy

Diabetes mellitus is one of the most frequent endocrine disorders, affecting populations worldwide. Diabetic retinopathy (DR) is the most frequent microvascular complication of diabetes in patients aged 20 and over. Major complications of DR include intraocular neovascularization, inter-retinal edema, hemorrhage, exudates and microaneurysms. Therefore, timely medical attention and prevention are required. At present, laser-assisted therapy and other operational procedures are the most common treatment for DR. However, these treatments can cause retinal damage and scarring. Also, use of the majority of traditional medicines is not supported by clinical evidence. However, due to accumulating scientific evidence, traditional natural medications may assist in delaying or preventing the progression of DR. This review focuses on evidence for the role of traditional natural medicines and their mechanisms of action and pharmacological test results in relation to the progression of DR.

Chemical and Biological Aspects of Extracts from Medicinal Plants with Antidiabetic Effects

Diabetes mellitus is a chronic disease and a leading cause of death in western countries. Despite advancements in the clinical management of the disease, it is not possible to control the late complications of diabetes. The main characteristic feature of diabetes is hyperglycemia, which reflects the deterioration in the use of glucose due to a faulty or poor response to insulin secretion. Alloxan and streptozotocin (STZ) are the chemical tools that are most commonly used to study the disease in rodents. Many plant species have been used in ethnopharmacology or to treat experimentally symptoms of this disease. When evaluated pharmacologically, most of the plants employed as antidiabetic substances have been shown to exhibit hypoglycemic and antihyperglycemic activities, and to contain chemical constituents that may be used as new antidiabetic agents. There are many substances extracted from plants that offer antidiabetic potential, whereas others may result in hypoglycemia as a side effect due to their toxicity, particularly their hepatotoxicity. In this article we present an updated overview of the studies on extracts from medicinal plants, relating the mechanisms of action by which these substances act and the natural principles of antidiabetic activity.

Prevention of atherosclerosis by Yindan Xinnaotong capsule combined with swimming in rats

BACKGROUND

Yindan Xinnaotong capsule has been used for treating cardio-cerebrovascular diseases for several decades in China. Exercise training can protect against the development of atherosclerosis. The aim of the present study is to evaluate the joint effect of YXC and exercise on atherosclerosis in rats.

METHODS

A combined method involving low shear stress and a high-fat diet was used to establish the atherosclerosis model in rats. Partial ligation of the left common carotid artery was performed, and then the rats were divided into 9 treatment groups according to a 3 × 3 factorial design with two factors and three levels for each factor, swimming of 0, 0.5, 1 h daily and YXC administration of 0, 1, 2 g/kg p.o. daily. Next the interventions of swimming and YXC were executed for 8 weeks. After that, blood samples were collected to determine blood viscosity, plasma viscosity, haematocrit (HCT), fibrinogen (FIB), blood lipid profile (including total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C), triglyceride (TG) and high-density lipoprotein-cholesterol (HDL-C)), nitric oxide (NO), 6-keto- prostaglandin (PG) F1α, endothelin (ET) and thromboxane (TX) B2. The common carotid arteries of the rats were harvested to examine pathological changes, wall thickness and circumference, and the expression of SM22αwas assayed via immune-histochemistry.

RESULTS

The early pathological changes were observed. The joint effects of YXC and swimming showed significant changes in the examined parameters: (1) decreases in plasma viscosity, blood viscosity and FIB; (2) increases in NO and 6-keto-PGF1α; (3) decreases in ET and TXB2; and (4) decreases in LDL-C and TG. The combination of 2 g/kg YXC and 1 h of swimming led to synergistic decreases in LDL-C and TG. The interactive effect between YXC and swimming was obvious in decreasing wall thickness. Swimming alone was able to up-regulate the expression of SM22α.

CONCLUSIONS

In conclusion, this study indicates that the combination of YXC and swimming may prevent atherosclerosis through a synergistic effect between YXC and swimming in improving blood circulation, hemorheological parameters, blood lipids levels and the vascular endothelium in rats. The vascular remodeling may be contributed to the prevention effects on AS by up-regulating SM22α.