Inhibition of glucose-induced vascular endothelial growth factor expression by Salvia miltiorrhiza hydrophilic extract in human microvascular endothelial cells: evidence for mitochondrial oxidative stress

Treatment of diabetic retinopathy with herbs for tonifying kidney and activating blood circulation: A review of pharmacological studies

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetic retinopathy (DR) is a prevalent microvascular complication of diabetes. Chinese medicine believes that kidney deficiency and blood stasis are significant pathogenesis of DR. A characteristic therapeutic approach for this pathogenesis is the kidney-tonifying and blood-activating method. By literature retrieval from several databases, we methodically summarized the commonly used kidney-tonifying and blood-activating herbs for treating DR, including Lycii Fructus, Rehmanniane Radix Praeparata, and Corni Fructus with the function of nourishing kidney; Salvia Miltiorrhizae Radix et Rhizoma with the function of enhancing blood circulation; Rehmanniae Radix with the function of nourishing kidney yin; and Astragali Radix with the function of tonifying qi. It has been demonstrated that these Chinese herbs described above, by tonifying the kidney and activating blood circulation, significantly improve the course of DR.

AIM OF THE STUDY

Through literature research, to gain a thorough comprehension of the pathogenesis of DR. Simultaneously, through the traditional application analysis, modern pharmacology research and network pharmacology analysis of kidney-tonifying and blood-activating herbs, to review the effectiveness and advantages of kidney-tonifying and blood-activating herbs in treating DR comprehensively.

MATERIALS AND METHODS

PubMed, the China National Knowledge Infrastructure (CNKI), and Wanfang Data were used to filter the most popular herbs for tonifying kidney and activating blood in the treatment of DR. The search terms were "diabetic retinopathy" and "tonifying kidney and activating blood". Mostly from 2000 to 2023. Network pharmacology was applied to examine the key active components and forecast the mechanisms of kidney-tonifying and blood-activating herbs in the treatment of DR.

RESULTS

Kidney deficiency and blood stasis are the pathogenesis of DR, and the pathogenesis is linked to oxidative stress, inflammation, hypoxia, and hyperglycemia. Scientific data and network pharmacology analysis have demonstrated the benefit of tonifying kidney and activating blood herbs in treating DR through several channels, multiple components, and multiple targets.

CONCLUSIONS

This review first presents useful information for subsequent research into the material foundation and pharmacodynamics of herbs for tonifying kidney and activating blood, and offers fresh insights into the treatment of DR.

Systematic investigation of Radix Salviae for treating diabetic peripheral neuropathy disease based on network Pharmacology

BACKGROUND

Diabetic peripheral neuropathy (DPN) is a debilitating complication of diabetes mellitus with limited available treatment options. Radix Salviae, a traditional Chinese herb, has shown promise in treating DPN, but its therapeutic mech-anisms have not been systematically investigated.

AIM

Radix Salviae (Danshen in pinin), a traditional Chinese medicine (TCM), is widely used to treat DPN in China. However, the mechanism through which Radix Salviae treats DPN remains unclear. Therefore, we aimed to explore the mechanism of action of Radix Salviae against DPN using network pharmacology.

METHODS

The active ingredients and target genes of Radix Salviae were screened using the TCM pharmacology database and analysis platform. The genes associated with DPN were obtained from the Gene Cards and OMIM databases, a drug-com-position-target-disease network was constructed, and a protein-protein inter-action network was subsequently constructed to screen the main targets. Gene Ontology (GO) functional annotation and pathway enrichment analysis were performed via the Kyoto Encyclopedia of Genes and Genomes (KEGG) using Bioconductor.

RESULTS

A total of 56 effective components, 108 targets and 4581 DPN-related target genes of Radix Salviae were screened. Intervention with Radix Salviae for DPN mainly involved 81 target genes. The top 30 major targets were selected for enrichment analysis of GO and KEGG pathways.

CONCLUSION

These results suggested that Radix Salviae could treat DPN by regulating the AGE-RAGE signaling pathway and the PI3K-Akt signaling pathway. Therefore, Danshen may affect DPN by regulating inflammation and apoptosis.

Protective effect of Cordyceps sinensis against diabetic kidney disease through promoting proliferation and inhibiting apoptosis of renal proximal tubular cells

BACKGROUND

Diabetic kidney disease (DKD) has mainly been considered as a glomerular disease. Our previous study showed that the progression of DKD was highly correlated with the dysfunction of renal proximal tubular cells. Fermented Cordyceps sinensis (CS), a substitute for natural CS, is a prominent herb widely used in China, and has exhibited excellent efficacy on DKD. However, the underlying mechanisms remain poorly understood.

METHODS

The database analysis was used to identify the main therapeutic targets and pathways of CS involved in DKD treatment. Next, the protective effects of fermented CS on high glucose (HG, 30 mM) induced HK-2 cell injury was validated through cell proliferation and apoptosis assay, including CCK-8, EdU and TUNEL. Finally, quantitative real‑time PCR (qRT-PCR) and western blotting were used to verify key target genes.

RESULTS

Our results revealed that 9 main targets (RELA, JNK1, PTEN, VEGFA, EGF, ERK2, CASP3, AKT1, MMP9) were recognized as key therapeutic targets with excellent binding affinity screened by database analysis and molecular docking. The biological processes were identified by Gene Ontology (GO) enrichment, which appeared mainly involved in the positive regulation of cell proliferation as well as the negative regulation of apoptosis. The verification experiments in vitro revealed that fermented CS significantly attenuated the HG-induced cytotoxicity and apoptosis, and promoted the proliferation of HK-2 cells. Moreover, fermented CS significantly downregulated the expressions of Bax, Caspase-3, VEGFA, P-AKT and P-ERK, and upregulated the expression of PTEN compared with that of HG group.

CONCLUSION

Our results demonstrate that the fermented CS has nephroprotective effects significantly, which functions via promoting proliferation and inhibiting apoptosis of renal proximal tubular cells, likely by targeting Caspase-3, Bax, VEGFA and PTEN. Furthermore, AKT and ERK signaling pathway may be the critical mechanisms underlying the efficacy of fermented CS in DKD treatment.

Exploration of the Specific Pathology of HXMM Tablet Against Retinal Injury Based on Drug Attack Model to Network Robustness

Retinal degenerative diseases are related to retinal injury because of the activation of the complement cascade, oxidative stress-induced cell death mechanisms, dysfunctional mitochondria, chronic neuroinflammation, and production of the vascular endothelial growth factor. Anti-VEGF therapy demonstrates remarkable clinical effects and benefits in retinal degenerative disease patients. Hence, new drug development is necessary to treat patients with severe visual loss. He xue ming mu (HXMM) tablet is a CFDA-approved traditional Chinese medicine (TCM) for retinal degenerative diseases, which can alleviate the symptoms of age-related macular degeneration (AMD) and diabetic retinopathy (DR) alone or in combination with anti-VEGF agents. To elucidate the mechanisms of HXMM, a quantitative evaluation algorithm for the prediction of the effect of multi-target drugs on the disturbance of the disease network has been used for exploring the specific pathology of HXMM and TCM precision positioning. Compared with anti-VEGF agents, the drug disturbance of HXMM on the functional subnetwork shows that HXMM reduces the network robustness on the oxidative stress subnetwork and inflammatory subnetwork to exhibit the anti-oxidation and anti-inflammation activity. HXMM provides better protection to ARPE-19 cells against retinal injury after H₂O₂ treatment. HXMM can elevate GSH and reduce LDH levels to exhibit antioxidant activity and suppress the expression of IL-6 and TNF-α for anti-inflammatory activity, which is different from the anti-VEGF agent with strong anti-VEGF activity. The experimental result confirmed the accuracy of the computational prediction. The combination of bioinformatics prediction based on the drug attack on network robustness and experimental validation provides a new strategy for precision application of TCM.

Effect of Shuangdan Mingmu Capsule on Diabetic Retinopathy in Rats via Regulation of miRNAs

PURPOSE

To evaluate the effects of Shuangdan Mingmu (SDMM) capsule on diabetic retinopathy in rats by regulating miRNAs.

MATERIALS AND METHODS

Streptozotocin (STZ) (50 mg/kg) was successfully used to induce diabetes in male Sprague-Dawley rats, which were randomly assigned to a group taking SDMM capsules ("diabetic+SDMM") or a control group ("diabetic"), and the normal group (n=10/group). The diabetic+SDMM capsule group received 1.89g/kg/d of SDMM capsule by gavage, whereas the other groups received the same amount of distilled water. After 12-weeks of gavage, the retina was removed from all rats for histopathological analysis, and miRNA sequencing experiments were carried out to identify the differential expression of miRNAs. These results were then confirmed by quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

SDMM capsules improved retinal morphology, restored the number of cells in the ganglion cell layer (p<0.0001) and reduced apoptosis in all retinal layers (p values in the outer nuclear layers, inner nuclear layers and ganglion cell layers 0.0001, 0.0147, 0.0034, respectively). In addition, miRNA expression was changed in rats taking SDMM capsules. Compared with the diabetic group, six miRNAs were up-regulated and four miRNAs were down-regulated in the diabetic+SDMM capsule group. The qRT-PCR validation results showed that the expression levels of miR-450b-5p, miR-1249 and miR-155-5p were consistent with the trend of miRNA sequencing results, and were all up-regulated after SDMM capsule treatment. Target gene prediction and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of differentially expressed miRNAs showed that these pathways were mainly concentrated in the focal adhesions and PI3K/Akt, MAPK, and neural factor signaling pathways.

CONCLUSION

SDMM capsules may prevent and treat diabetic retinopathy by regulating the expression of miR-450b-5p, miR-1249 and miR-155-5p.

Salvia miltiorrhiza Protects Endothelial Dysfunction against Mitochondrial Oxidative Stress

Salvia miltiorrhiza (SM) is a common traditional Chinese medicine used in the treatment of cardiovascular and cerebrovascular diseases. Endothelial dysfunction plays an important role in the pathology of cardiovascular diseases. Endothelial dysfunction may induce inflammation and change vascular tone and permeability. The main pathological mechanism of endothelial dysfunction is the formation of reactive oxygen species (ROS). Mitochondria are the main source of energy and can also produce large amounts of ROS. Recent studies have shown that extracts of SM have antioxidative, anti-inflammatory, and antithrombus properties. In this review, we discuss the mechanism of oxidative stress in the mitochondria, endothelial dysfunction, and the role of SM in these oxidative events.

Salvia miltiorrhiza prevents methylglyoxal-induced glucotoxicity via the regulation of apoptosis-related pathways and the glyoxalase system in human umbilical vein endothelial cells

Methylglyoxal (MGO), which is produced as a byproduct of glucose metabolism, is the leading to diabetic cardiovascular complications. Salvia miltiorrhiza Bunge (Lamiaceae) has been reported as a potential plant to control diabetes and cardiovascular disease. However, no report exists on the effect of Salvia miltiorrhiza Bunge extract (SME) on MGO-induced glucotoxicity in human umbilical vein endothelial cells (HUVECs).We demonstrated the protective effects of SME (1, 5, and 10 µg/mL) and its components against MGO-induced endothelial dysfunction in HUVECs. Cytotoxicity was evaluated using the several in vitro experiments. Additionally, the protein expression of receptor of advanced glycation end-products (RAGE), mitogen-activated protein kinase (MAPK) pathway and glyoxalase system were measured. Then, the inhibitory effects of SME and its main components on MGO-induced oxidative stress, radical scavenging, formation of MGO-derived advanced glycation end products (AGEs), and MGO-AGEs crosslinking were evaluated.SME (10 µg/mL) strongly prevented expressed levels of RAGE, MGO-induced apoptosis and reduced ROS generation in HUVECs, comparing with 1 mM aminoguanidine. Additionally, SME (5 and 10 µg/mL) reduced the expression of proteins (e.g., p-ERK and p-p38) in the MAPKs pathway and upregulated the glyoxalase system in HUVECs. SME (0.5 - 10 mg/mL), dihydrotanshinone (0.4 mM), and rosmarinic acid (0.4 mM) prevented MGO-AGEs formation and broke the MGO-AGE crosslinking. These results show that S. miltiorrhiza has protective effects against MGO-induced glucotoxicity by regulating the proteins involved in apoptosis, glyoxalase system and antioxidant activity.We expect that S. miltiorrhiza is a potential natural resource for the treatment of MGO-induced vascular endothelial dysfunction.

Evaluation of the Antidiabetic and Antihyperlipidemic Activity of Spondias purpurea Seeds in a Diabetic Zebrafish Model

Diabetes mellitus (DM) is a serious chronic degenerative disease characterized by high levels of glucose in the blood. It is associated with an absolute or relative deficiency in the production and/or action of insulin. Some of the complications associated with DM are heart disease, retinopathy, kidney disease, and neuropathy; therefore, new natural alternatives are being sought to control the disease. In this work, we evaluate the antidiabetic effect of Spondias purpurea seed methanol extract (CSM) in vitro and in a glucose-induced diabetic zebrafish model. CSM is capable of lowering blood glucose and cholesterol levels, as well as forming advanced glycation end-products, while not presenting toxic effects at the concentrations evaluated. These data show that CSM has a promising antidiabetic effect and may be useful in reducing some of the pathologies associated with diabetes mellitus.

An Optimal Combination of Chemically Pure Compounds from Salvia Miltiorrhiza for Inhibiting Cell Proliferation

OBJECTIVE

Salvia Miltiorrhiza (SM) is a traditional Chinese medicine used clinically to treat cardiovascular diseases including atherosclerosis and myocardial infarction. Its therapeutic effect has been confirmed by many clinical and pharmacological studies. However, the optimal formulation of active ingredients in SM for treating cardiovascular diseases remains unclear. In this study, we determined the ratio of the optimal compatibility of SM ingredients DSS, Sal-A, Sal-B, and PAL (SABP）with a uniform and orthogonal optimized experimental design. In addition, we determined the anti-oxidation effect of SABP using Adventitial Fibroblasts (AFs).

METHODS

By using a combination of uniform and orthogonal designs, we determined the optimal formulation of aqueous extract from SM. MTT assay was used to determine the inhibitory effects of these 4 components of SM on the AFs, which were isolated and cultured from aorta. The reactive oxygen species (ROS) production in AFs was compared before and after SABP treatment.

RESULTS

The optimal formulation of these 4 aqueous extracts from SM were 150︰7︰300︰500, and their concentrations were S(1.5×10-4 mol/L), A(7×10-6 mol/L), B(3×10-4 mol/L), and P(5×10-4 mol/L). There were some synergies between these 4 components. Moreover, SABP decreased ROS production in AFs.

CONCLUSION

These findings suggest that SABP inhibits the proliferation and oxidation stress in AFs. The present study provides a new evidence that the efficacy and function generated from optimal formulation of active ingredients in SM are better than lyophilized powder of SM.

Salvia miltiorrhiza in diabetes: A review of its pharmacology, phytochemistry, and safety

BACKGROUND

Salvia miltiorrhiza (SM), one of the frequently used herbs in traditional Chinese medicine (TCM), has now attracted rising interests for a possible alternative in the management of diabetes. This review is aimed to providing a comprehensive perspective of SM in phytochemical constituents, pharmacological activities against diabetes and its complications, and safety.

METHODS

A comprehensive search of published literatures was conducted to locate original publications pertaining to SM and diabetes till the end of 2017 using PubMed, China National Knowledge Infrastructure, National Science and Technology Library, China Science and Technology Journal Database, and Web of Science database. The main inquiry was used for the presence of the following keywords in various combinations in the titles and abstracts: Salvia miltiorrhiza, diabetes, obesity, phytochemistry, pharmacology, and safety. About 200 research papers and reviews were consulted.

RESULTS

SM exhibited anti-diabetic activities by treating macro- and micro-vascular diseases in preclinical experiments and clinical trials through an improvement of redox homeostasis and inhibition of apoptosis and inflammation via the regulation of Wnt/β-catenin, TSP-1/TGF-β1/STAT3, JNK/PI3K/Akt, kinin B2 receptor-Akt-GSK-3β, AMPKβ/PGC-1α/Sirt3, Akt/AMPK, TXNIP/NLRP3, TGF-β1/NF-κB, mineralocorticoid receptor/Na⁺/K⁺-ATPase, AGEs/RAGE, Nrf2/Keap1, CaMKKβ/AMPK, AMPK/ACC, IRS-1/PI3K signaling pathways, and modulation of K⁺-Ca²⁺ channels, as well as influence of VEGF, NOS, AGEs, PPAR expression and hIAPP aggregation. The antidiabetic effects of this herb may be related to its TCM characters of improving blood circulation and reliving blood stasis. The main ingredients of SM included salvianolic acids and diterpenoid tanshinones, which have been well studied in the diabetic animals. Acute and subacute toxicity studies supported the notion that SM is well tolerated.

CONCLUSION

SM may offer a new strategy for prevention and treatment of diabetes and its complications that stimulates extensive research into identifying potential anti-diabetic compounds and fractions as well as exploring the underlying mechanisms of this herb. Further scientific evidences are still required from well-designed preclinical experiments and clinical trials on its anti-diabetic effects and safety.

Cellular and Molecular Mechanisms of Diabetic Atherosclerosis: Herbal Medicines as a Potential Therapeutic Approach

An increasing number of patients diagnosed with diabetes mellitus eventually develop severe coronary atherosclerosis disease. Both type 1 and type 2 diabetes mellitus increase the risk of cardiovascular disease associated with atherosclerosis. The cellular and molecular mechanisms affecting the incidence of diabetic atherosclerosis are still unclear, as are appropriate strategies for the prevention and treatment of diabetic atherosclerosis. In this review, we discuss progress in the study of herbs as potential therapeutic agents for diabetic atherosclerosis.

Oxidative Stress and Salvia miltiorrhiza in Aging-Associated Cardiovascular Diseases

Aging-associated cardiovascular diseases (CVDs) have some risk factors that are closely related to oxidative stress. Salvia miltiorrhiza (SM) has been used commonly to treat CVDs for hundreds of years in the Chinese community. We aimed to explore the effects of SM on oxidative stress in aging-associated CVDs. Through literature searches using Medicine, PubMed, EMBASE, Cochrane library, CINAHL, and Scopus databases, we found that SM not only possesses antioxidant, antiapoptotic, and anti-inflammatory effects but also exerts angiogenic and cardioprotective activities. SM may reduce the production of reactive oxygen species by inhibiting oxidases, reducing the production of superoxide, inhibiting the oxidative modification of low-density lipoproteins, and ameliorating mitochondrial oxidative stress. SM also increases the activities of catalase, manganese superoxide dismutase, glutathione peroxidase, and coupled endothelial nitric oxide synthase. In addition, SM reduces the impact of ischemia/reperfusion injury, prevents cardiac fibrosis after myocardial infarction, preserves cardiac function in coronary disease, maintains the integrity of the blood-brain barrier, and promotes self-renewal and proliferation of neural stem/progenitor cells in stroke. However, future clinical well-designed and randomized control trials will be necessary to confirm the efficacy of SM in aging-associated CVDs.

Salvia miltiorrhiza: Traditional medicinal uses, chemistry, and pharmacology

Salvia miltiorrhiza Bunge (SM) is a very popular medicinal plant that has been extensively applied for many years to treat various diseases, especially coronary heart diseases and cerebrovascular diseases, either alone or in combination with other Chinese plant-based medicines. Although a large number of studies on SM have been performed, they are scattered across a variety of publications. The present review is an up-to-date summary of the published scientific information about the traditional uses, chemical constituents, pharmacological effects, side effects, and drug interactions with SM, in order to lay the foundation for further investigations and better utilization of SM. SM contains diverse chemical components including diterpenoid quinones, hydrophilic phenolic acids, and essential oils. Many pharmacological studies have been done on SM during the last 30 years, focusing on the cardiovascular and cerebrovascular effects, and the antioxidative, neuroprotective, antifibrotic, anti-inflammatory, and antineoplastic activities. The research results strongly support the notion that SM has beneficial therapeutic properties and has a potential of being an effective adaptogenic remedy.

Mitochondrial uncoupling proteins regulate angiotensin-converting enzyme expression: crosstalk between cellular and endocrine metabolic regulators suggested by RNA interference and genetic studies

Uncoupling proteins (UCPs) regulate mitochondrial function, and thus cellular metabolism. Angiotensin‐converting enzyme (ACE) is the central component of endocrine and local tissue renin–angiotensin systems (RAS), which also regulate diverse aspects of whole‐body metabolism and mitochondrial function (partly through altering mitochondrial UCP expression). We show that ACE expression also appears to be regulated by mitochondrial UCPs. In genetic analysis of two unrelated populations (healthy young UK men and Scandinavian diabetic patients) serum ACE (sACE) activity was significantly higher amongst UCP3‐55C (rather than T) and UCP2 I (rather than D) allele carriers. RNA interference against UCP2 in human umbilical vein endothelial cells reduced UCP2 mRNA sixfold (P < 0·01) whilst increasing ACE expression within a physiological range (<1·8‐fold at 48 h; P < 0·01). Our findings suggest novel hypotheses. Firstly, cellular feedback regulation may occur between UCPs and ACE. Secondly, cellular UCP regulation of sACE suggests a novel means of crosstalk between (and mutual regulation of) cellular and endocrine metabolism. This might partly explain the reduced risk of developing diabetes and metabolic syndrome with RAS antagonists and offer insight into the origins of cardiovascular disease in which UCPs and ACE both play a role.

Mitochondrial mechanisms of endothelial dysfunction

Endothelial cells play an important physiological role in vascular homeostasis. They are also the first barrier that separates blood from deeper layers of blood vessels and extravascular tissues. Thus, they are exposed to various physiological blood components as well as challenged by pathological stimuli, which may exert harmful effects on the vascular system by stimulation of excessive generation of reactive oxygen species (ROS). The major sources of ROS are NADPH oxidase and mitochondrial respiratory chain complexes. Modulation of mitochondrial energy metabolism in endothelial cells is thought to be a promising target for therapy in various cardiovascular diseases. Uncoupling protein 2 (UCP2) is a regulator of mitochondrial ROS generation and can antagonise oxidative stress-induced endothelial dysfunction. Several studies have revealed the important role of UCP2 in hyperglycaemia-induced modifications of mitochondrial function in endothelial cells. Additionally, potassium fluxes through the inner mitochondrial membrane, which are involved in ROS synthesis, affect the mitochondrial volume and change both the mitochondrial membrane potential and the transport of calcium into the mitochondria. In this review, we concentrate on the mitochondrial role in the cytoprotection phenomena of endothelial cells.

Increased activity of mitochondrial uncoupling protein 2 improves stress resistance in cultured endothelial cells exposed in vitro to high glucose levels

The endothelium is relatively independent of the mitochondrial energy supply, but mitochondria-derived ROS may play an important role in the development of many cardiovascular diseases. Energy-dissipating uncoupling proteins (UCPs) mediate free fatty acid-activated, purine nucleotide-inhibited proton conductance (uncoupling) in the inner mitochondrial membrane. We have described a functional characteristic and an antioxidative role for UCP2 in endothelial cells and isolated mitochondria and how this function is altered by long-term growth in high concentrations of glucose. Human umbilical vein endothelial cells (EA.hy926 line) were grown in media with either high (25 mM) or normal (5.5 mM) glucose concentrations. Under nonphosphorylating and phosphorylating conditions, UCP activity was significantly higher in mitochondria isolated from high glucose-treated cells. More pronounced control of the respiratory rate, membrane potential, and ROS by UCP2 was observed in these mitochondria. A greater UCP2-mediated decrease in ROS generation indicates an improved antioxidative role for UCP2 under high glucose conditions. Mitochondrial and nonmitochondrial ROS generations were significantly higher in high glucose-treated cells independent of UCP2 expression. UCP2 gene silencing led to elevated mitochondrial ROS formation and ICAM1 expression, especially in high glucose-cultured cells. UCP2 influenced endothelial cell viability and resistance to oxidative stress. Endothelial cells exposed to high glucose concentrations were significantly more resistant to peroxide. In these cells, the increased activity of UCP2 led to improved stress resistance and protection against acute oxidative stress. Our results indicate that endothelial UCP2 may function as a sensor and negative regulator of mitochondrial ROS production in response to hyperglycemia.

Ancient records and modern research on the mechanisms of chinese herbal medicines in the treatment of diabetes mellitus

Over the past decades, Chinese herbal medicines (CHM) have been extensively and intensively studied through from both clinical and experimental perspectives and CHM have been proved to be effective in the treatment of diabetes mellitus (DM). This study, by searching ancient records and modern research papers, reviewed CHM in terms of their clinical application and principal mechanism in the treatment of DM. We summarized the use of CHM mentioned in 54 famous ancient materia medica monographs and searched papers on the hypoglycemic effect of several representative CHM. Main mechanisms and limitations of CHM and further research direction for DM were discussed. On the basis of the study, we were led to conclude that TCM, as a main form of complementary and alternative medicine (CAM), was well recorded in ancient literatures and has less adverse effects as shown by modern studies. The mechanisms of CHM treatment of DM are complex, multilink, and multitarget, so we should find main hypoglycemic mechanism through doing research on CHM monomer active constituents. Many CHM monomer constituents possess noteworthy hypoglycemic effects. Therefore, developing a novel natural product for DM and its complications is of much significance. It is strongly significant to pay close attention to CHM for treatment of DM and its complications.

Protective effects of Salvia miltiorrhiza injection against learning and memory impairments in streptozotocin-induced diabetic rats

The aim of this study was to explore the protective effects of Salvia miltiorrhiza injection against learning and memory impairment in streptozotocin (STZ)-induced diabetic rats and the possible mechanism involved. Sprague Dawley male rats (n=30) were randomized into three groups: Diabetes, diabetes treated with S. miltiorrhiza injection and normal control. Diabetes was induced by an intraperitoneal injection of STZ (65 mg/kg). The S. miltiorrhiza injection-treated rats received an intraperitoneal injection of S. miltiorrhiza (5 ml/kg/day) while the rats of the other two groups were administered an intraperitoneal injection of the same volume of 0.9% saline for four weeks. After four weeks of treatment, the escape latency and search strategies in the rats were assessed by the Morris water maze test. The protein levels of mitogen-activated protein kinase phosphatase-1 (MKP-1) were also assessed by immunohistochemistry. Four weeks after the induction of diabetes, the body weight of the diabetic rats was significantly lower and the blood glucose concentration was significantly higher than that of the control rats. S. miltiorrhiza injection was observed to improve the blood glucose and learning ability (P<0.05). Compared with the control group, the expression of MKP-1 was significantly decreased in the hippocampal area of the diabetes group; S. miltiorrhiza injection-treated rats showed an increased expression compared with the diabetic rats, but the expression remained lower than that of the normal control group (P<0.05). In conclusion, S. miltiorrhiza injection can improve the learning and memory decline of diabetic rats. The changes in expression of MKP-1 under hyperglycemia may play a role in the protective effects of S. miltiorrhiza against dementia in diabetic rats.

Phyllanthus urinaria induces mitochondrial dysfunction in human osteosarcoma 143B cells associated with modulation of mitochondrial fission/fusion proteins

Phyllanthus urinaria (P. urinaria), a widely used herbal medicine, has been reported to possess various biological characteristics including anti-inflammation, anti-virus, anti-bacteria, anti-hepatotoxicity and anti-cancer. This study provides molecular evidence associated with the dynamics and organization of mitochondria in osteosarcoma 143B cells resulted from P urinaria. Herein, P. urinaria-induced cytotoxicity and ROS associated with the inhibition of mitochondrial membrane potential were reversed by N-acetylcysteine (NAC). The endogenous antioxidant enzymes such as manganese superoxide dismutase (MnSOD) and glutathione peroxidase (GPX1) were activated by P. urinaria, but not correlated to catalase. P. urinaria decreased mitochondrial respiration activity as well as respiratory chain enzymes and HIF-1α in osteosarcoma 143B cells. Additionally, both adenosine triphosphate (ATP) synthase activation and ATP production were suppressed by P. urinaria. We further investigated changes of mitochondrial dynamic in osteosarcoma 143B cells. P. urinaria indeed fragmented the mitochondrial network of osteosarcoma 143B cells. We found a significant decrease in optic atrophy type 1 (Opa1) and mitofusin 1 (Mfn1) related to fusion proteins as well as increase mitochondrial fission 1 protein (Fis1) related to fission protein. It indicated that P. urinaria modulated the mitochondrial dynamics via fusion and fission machinery. Altogether, this study offers the evidence that mitochondrial dysfunction with dynamic change is essential components for the anti-cancer mechanism elicited by P. urinaria.

Effect of Danshen aqueous extract on serum hs-CRP, IL-8, IL-10, TNF-α levels, and IL-10 mRNA, TNF-α mRNA expression levels, cerebral TGF-β1 positive expression level and its neuroprotective mechanisms in CIR rats

To observe the effects of Danshen aqueous extract (DSAE) on the cerebral tissue and nerve stem cells in cerebral ischemia reperfusion (CIR) rats. The model rats were prepared by occlusion of the middle cerebral artery for 2 h and then by reperfusion. They were randomly divided into five groups: a control group, an CIR group and three DSAE-treated groups. As compared with the sham control group, there was significant increase (P < 0.05, P < 0.01) in the serum high-sensitivity C-reactive protein (hs-CRP) and interleukin-8 (IL-8) levels, interleukin-10 (IL-10), tumor necrosis factor-alpha (TNF-α) levels, and IL-10 mRNA, TNF-α mRNA expression levels, function score, Infarct size, TUNEL + cell counts, cerebral transforming growth factor beta 1 (TGF-β1) positive expression and cerebral neuron specific enolase (NSE) levels, and decrease in fas-associated protein with death domain (FADD) and death-associated protein (Daxx) positive expression levels in the CIR group. Compared with CIR group, DSAE treatment dose-dependently significantly decreased serum hs-CRP, IL-8, IL-10, TNF-α levels, and IL-10 mRNA, TNF-α mRNA expression levels, function score, Infarct size, TUNEL + cell counts, cerebral TGF-β1 positive expression and cerebral NSE levels, and increase FADD and Daxx positive expression levels in the CIR + DSAE groups. Taken together, these results suggest that DSAE has a neuroprotective role in the CIR rats, which may be related to improvement of immunity function, proteins and genes expression.

Myocardial protection by Salvia miltiorrhiza Injection in streptozotocin-induced diabetic rats through attenuation of expression of thrombospondin-1 and transforming growth factor-β1

OBJECTIVES

To investigate the myocardially protective effects of Salvia miltiorrhiza injection in streptozotocin-induced diabetic rats and the possible mechanisms involved.

METHODS

Adult male Sprague-Dawley rats were randomized into three groups (n = 10 per group): diabetes, no treatment (Sm-); diabetes, S. miltiorrhiza injection (Sm+); control (no diabetes; saline treatment). After model induction and 4 weeks' treatment, heart function of five rats from each group was tested by Langendorff isolated in vivo heart perfusion. In the remaining rats, pathological changes of the myocardium were observed by haematoxylin and eosin staining, and protein levels of thrombospondin-1 (TSP-1) and transforming growth factor-β1 (TGF-β1) were assessed by immunohistochemistry.

RESULTS

Left ventricular systolic end pressure and left ventricular developed pressure were significantly improved in the Sm+ group compared with the Sm- group. Pathological changes were ameliorated through significantly reduced TSP-1 and TGF-β1 protein levels.

CONCLUSIONS

S. miltiorrhiza injection may improve the heart function of diabetic rats and protect against cardiomyopathy by downregulating TSP-1 and TGF-β1 in myocardial tissue.

Salvianolic acid B inhibits the amyloid formation of human islet amyloid polypeptide and protects pancreatic beta-cells against cytotoxicity

The misfolding of human islet amyloid polypeptide (hIAPP) is regarded as one of the causative factors of type 2 diabetes mellitus (T2DM). Salvia miltiorrhiza (Danshen), one of the most commonly used of traditional Chinese medicines, is often used in Compound Recipes for treating diabetes, however with unclear mechanisms. Since salvianolic acid B (SalB) is the most abundant bioactive ingredient of salvia miltiorrhiza water-extract. In this study, we tested whether SalB has any effect on the amyloidogenicity of hIAPP. Our results clearly suggest that SalB can significantly inhibit the formation of hIAPP amyloid and disaggregate hIAPP fibrils. Furthermore, photo-crosslinking based oligomerization studies suggest SalB significantly suppresses the toxic oligomerization of hIAPP monomers. Cytotoxicity protection effects on pancreatic INS-1 cells by SalB were also observed using MTT-based assays, potentially due to the inhibition on the membrane disruption effects and attenuated mitochondria impairment induced by hIAPP. These results provide evidence that SalB may further be studied on the possible pharmacological treatment for T2DM.

Hepatoprotective and antioxidant effects of Myelophil on restraint stress-induced liver injury in BALB/c mice

ETHNOPHARMACOLOGIC RELEVANCE

Myelophil, an ethanol extract of Astragali Radix and Salviae Radix, has been used for patients with chronic fatigue-associated disorders in traditional Oriental clinics.

AIM OF THE STUDY

This study aimed to evaluate the pharmacologic effects of Myelophil using a restraint stress-induced liver injury model and to explore the mechanisms underlying these effects.

MATERIALS AND METHODS

Distilled water or Myelophil (50 mg/kg, 100 mg/kg, or 200 mg/kg) was orally administered to 6-week-old BALB/c male mice once daily for 5 day. The mice were subjected to restraint stress for 6h, and serum levels of aspartate and alanine aminotransferases (AST and ALT, respectively), total reactive oxygen species, and total antioxidant capacity were determined. Hepatic tissue levels of lipid peroxidation, antioxidant activity (as represented by superoxide dismutase, catalase, and glutathione reductase activity), and interleukin-1 were also measured.

RESULTS

Restraint stress induced severe oxidative stress and hepatic injury, as evidenced by marked elevation of serum ALT and AST levels, increased levels of reactive oxygen species and lipid peroxidation activity, and depletion of antioxidant enzyme activities. Myelophil pretreatment significantly attenuated not only the elevation of serum ALT and AST but also the increase in reactive oxygen species and lipid peroxidation. It also restored a significant fraction of the catalase, glutathione reductase, and peroxidase activity in liver tissues. Myelophil pretreatment also partially normalized the levels of interleukin-1β gene and protein expression.

CONCLUSIONS

These results suggest that Myelophil has potent protective effects against restraint stress-induced liver injury via antioxidant activities, and have relevance to the clinical applications of Myelophil in field of traditional herbal medicine.

Acute and sub-chronic toxicity studies of Danshen injection in Sprague-Dawley rats

ETHNOPHARMACOLOGICAL RELEVANCE

Salvia miltiorrhiza Bunge named Danshen in China has been used for hundreds of years in both China and other countries. Danshen injection made from the aqueous extract of Danshen which is widely adopted in China is one of the traditional Chinese medicine injections for preventing and treating cardiovascular diseases in most of the time. The present study was carried out on re-evaluating the safety of Danshen injection by determining toxicity after acute and sub-chronic administration in Sprague-Dawley (SD) rats.

MATERIALS AND METHODS

In acute toxicity study, rats (10 males and 10 females) were intravenously administered Danshen injection dose of 32g/kg body weight, two times in one day. General behavior, adverse effects and mortality were recorded for up to 14days post treatment. In the sub-chronic study, Danshen injection was given intravenously at the doses of 0, 1.92, 5.76, and 19.20g/kg per day (n=15/group each sex) for 13weeks to rats. Animal body weight and food intakes were observed weekly. Hematological, biochemical parameters and organ weight were determined in all animals at the end of the 13-week administration and 2-week recovery. However, histological examinations were carried out in the control and high-dose groups only.

RESULTS

In acute study, the sign of struggling was observed in some animals at the moment of intravenous administration. No deaths and other signs of toxicity occurred in any of the animals tested during the 14days of the study. In sub-chronic study, Danshen injection did not result to death, adverse effects or dose-dependent changes in food consumption, but had an effect on body weight gain. Some statistically significant differences were observed in hematological and biochemical parameters, as well as in some organ weights of both male and female rats treated with Danshen injection. In these changes, the significant decrease in triglycerides and increase in total bilirubin were considered related to treatment, indicating the lipid-modulating activity of Danshen. Histopathological examinations of the injection site showed that Danshen injection could cause dose-dependent focal inflammation. There was no abnormality of other organs noted in both gross and histopathological examinations.

CONCLUSIONS

The results showed that acute or sub-chronic administration of Danshen injection was low or non-toxic in male and female rats, and the no-observed-adverse-effect-level for sub-chronic administration of Danshen injection dose was 5.76g/kg bw/day, which was suggested that it was safe in clinical use.

Diabetes, oxidative stress, molecular mechanism, and cardiovascular disease--an overview

In recent years, diabetes and its associated complications have come to represent a major public health concern. It is a complex disease characterized by multiple metabolic derangements and is known to impair cardiac function by disrupting the balance between pro-oxidants and antioxidants at the cellular level. The subsequent generation of reactive oxygen species (ROS) and accompanying oxidative stress are hallmarks of the molecular mechanisms responsible for cardiovascular disease. Among several oxidative stress-mediated mechanisms that have been proposed, ROS-mediated oxidative stress has received the most attention. ROS have been shown to interact with proteins, lipids, and DNA, causing damage to the cellular macromolecules and subsequently, deterioration of cellular function. Induction of thioredoxin-1 (Trx1) gene expression has been demonstrated to protect the diabetic myocardium from dysfunction by reducing oxidative stress and enhancing the expression of heme oxygenase-1 (HO-1) and vascular endothelial growth factor (VEGF). The failure of antioxidants to consistently demonstrate clinical benefit necessitates further investigation of the role of oxidative stress in diabetes-mediated cardiovascular disease.