Effect of Buddleja officinalis on high-glucose-induced vascular inflammation in human umbilical vein endothelial cells

Buddleja officinalis Maxim.: A review of its botany, ethnopharmacology, phytochemistry, pharmacology, and therapeutic potential for ophthalmic diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Buddleja officinalis Maxim. (B. officinalis), commonly known as "Menghua" "Yangerduo" is a widely recognized traditional herbal medicine in China, Korea, and Vietnam. For thousands of years, it has been used to treat dry eye disease, conjunctivitis, keratitis, eye ulcers, eye pain, cough, asthma, hemoptysis, and other medical conditions.

AIM OF THE REVIEW

This review article aims to provide a concise summary of the botany, ethnopharmacology, phytochemistry, pharmacology, medicinal potential, and application of B. officinalis in treating ophthalmic diseases and critically evaluates the existing literature to establish a scientific basis for its reasonable utilization and further investigation.

MATERIALS AND METHODS

The information reviewed in this study was collected from various electronic resources, including the Web of Science, PubMed, and Google Scholar.

RESULTS

To date, 80 structurally diverse compounds have been isolated and characterized from B. officinalis, primarily flavonoids, phenylethanoids, triterpenoids, and monoterpenes. Extracts and compounds derived from B. officinalis have been reported to possess broad pharmacological effects including anti-dry eye disease, anti-inflammation, anti-oxidation, anti-diabetes, anti-obesity, improving osteoporosis and treatment of skin diseases. This review provides a reference for the future studies on of B. officinalis.

CONCLUSIONS

As a natural medicinal plant, B. officinalis is worthy of further development in botany, ethnopharmacology, phytochemistry, pharmacology, and therapeutic potential for ophthalmic diseases. Although some components have demonstrated multiple pharmacological activities, their mechanisms of action remain unclear. Further studies on the underlying molecular basis and mechanism of action are warranted.

Polyphenols from Penthorum chinense Pursh. Attenuates high glucose-induced vascular inflammation through directly interacting with Keap1 protein

ETHNOPHARMACOLOGICAL RELEVANCE

Penthorum chinense Pursh is used for promoting diuresis and alleviating "heat"-associated disorders, which were considered to be related to diabetic in Traditional Chinese Medicine (TCM).

AIMS OF THIS STUDY

Here, we aimed to evaluate the ability and underlying mechanism of the ethyl acetate fraction of Penthorum chinense Pursh stems (PSE) to inhibit vascular inflammation in high glucose (HG)-induced human umbilical vein endothelial cells (HUVEC cells).

MATERIALS AND METHODS

HUVEC cells were pre-treated with PSE following HG treatment. The cell viability, mitochondrial membrane potential (MMP), lactate dehydrogenase (LDH) levels, reactive oxygen species (ROS) generation were analyzed. Inflammatory, and antioxidant,-related proteins were analyzed using western blotting. Molecular docking and drug affinity targeting experiments (DARTS) were utilized to analyze and verify the binding of the Keap1 protein and polyphenols of PSE.

RESULTS

HG can significantly increase the activity of lactic dehydrogenase (LDH), destroy the mitochondrial membrane potential (MMP), and promote the generation of reactive oxygen species (ROS), while PSE treatment reversed these changes. Mechanistically, PSE inhibited NF-κB and inflammatory cytokines activation induced by HG through activating the expression of Nrf2 and its downstream antioxidant proteins Heme oxygenase-1 (HO-1), NAD (P)H Quinone Dehydrogenase 1 (NQO1), Glutamate cysteine ligase catalytic subunit (GCLC), Glutamate-cysteine ligase modifier (GCLM). Further study indicated that PSE activated Nrf2 antioxidant pathway mainly by the binding of primary polyphenols from PSE and the Keap1 protein.

CONCLUSION

Taken together, the present data highlight the health benefits of polyphenols from Penthorum chinense Pursh. regarding diabetes, proving it to be an important source of health care products. Besides, binding of the Keap1 protein may be an effective strategy to activate Nrf2 antioxidant pathway and prevent diabetes.

Extraction, Purification, Characterization, and Antiangiogenic Activity of Acidic Polysaccharide from Buddleja officinalis

Firstly, optimal parameters of crude polysaccharide from Buddleja officinalis were obtained as follows: ratio of water to raw material of 26 : 1, ultrasonic power of 240 W, ultrasonic time of 45 min, and ultrasonic temperature of 62°C. Secondly, acidic polysaccharide (APBOM) from Buddleja officinalis was successfully acquired with the yield of 9.57% by using DEAE-52 cellulose and Sephadex G-100 gel column chromatography. Then, we found that total polysaccharide content of APBOM was 94.37% with a sulfuric acid group of 1.68%, uronic acid content of 17.41%, and average molecular weight of 165.4 kDa. Finally, APBOM was confirmed to have significant antiangiogenic effects.

Nepeta angustifolia attenuates responses to vascular inflammation in high glucose-induced human umbilical vein endothelial cells through heme oxygenase-1 induction

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional folk medicine Nepeta angustifolia C. Y. Wu (NA) reportedly possesses various biological activities, such as anti-inflammatory, analgesic, antihypoxia, and antifatigue effects. In this study, we evaluated the anti-vascular inflammation effects of N. angustifolia extract in human umbilical vein endothelial cells (HUVECs) induced by high glucose (HG) as well as the underlying mechanisms and verified its activity in diabetic rats.

MATERIALS AND METHODS

HUVECs were exposed to 25 mM glucose to induce endothelial dysfunction. Adhesion molecule expression and reactive oxygen species (ROS) were assayed. IκB and IκB phosphorylation, nuclear factor-κB (NF-κB), HO-1 and nuclear factor erythroid 2-related factor 2 (Nrf2) were examined by Western blot. Nuclear localisation of Nrf2 was also examined using immunofluorescence. The in vivo study of NA was tested in diabetic rats in which the thoracic aorta and serum were collected to observe aorta histological change, and evaluate endothelial function and vascular inflammation.

RESULTS

The results revealed that HG can significantly promote the generation of ROS, the expression of cell adhesion molecules (CAMs), and the phosphorylation and degradation of IκB and NF-κB activation in HUVECs. These HG-induced phenomena were suppressed by NA-induced heme oxygenase (HO)- 1 expression in a dose- and time-dependent manner by activating Nrf2. The HO-1 inhibitor tin protoporphyrin also dramatically reversed the NA-induced inhibition of CAM expression and the reduction in ROS production. Furthermore, NA also elicited anti-vascular dysfunction effects in diabetic rats, where endothelial function was improved and vascular inflammation was alleviated.

CONCLUSION

All these findings indicated that NA attenuated high glucose-induced vascular dysfunction in vitro and in vivo.

Intravenous hMSCs Ameliorate Acute Pancreatitis in Mice via Secretion of Tumor Necrosis Factor-α Stimulated Gene/Protein 6

The administration of mesenchymal stem cells/multipotent mesenchymal stromal cells (MSCs) to enhance tissue repair is currently undergoing clinical trials. Some studies, including our previous work, have also revealed the beneficial effect of MSCs in severe acute pancreatitis (SAP); however, their mechanisms or mode of action remain controversial. In this study, we demonstrated that intravenously (i.v.)-administered human MSCs (hMSCs) remarkably promoted recovery from experimental SAP without significant engraftment of hMSCs in the damaged pancreas. Interestingly, we found that i.v.-administered hMSCs with knockdown of TSG-6 expression lost most of their anti-inflammatory effects and thus could not significantly ameliorate SAP. As expected, the effects of hMSCs were also duplicated by i.v. infusion of recombinant TSG-6. Furthermore, our results showed that the increase of oxidative stress, activation of the NLRP3 inflammasome and NF-κB signaling in SAP was substantially inhibited following administration of hMSCs or TSG-6, which was dependent on the presence of CD-44 receptors in acinar cells. In conclusion, our study, for the first time, revealed that novel mechanisms are responsible for the immunomodulatory effect of i.v. hMSCs.

Dehydrodiconiferyl alcohol suppresses monocyte adhesion to endothelial cells by attenuation of JNK signaling pathway

Several clinical studies have shown that the intake of aged garlic extract improves endothelial dysfunction. Lignan compounds, (+)-(2S,3R)-dehydrodiconiferyl alcohol (DDC) and (-)-(2R,3S)-dihydrodehydrodiconiferyl alcohol (DDDC), have been isolated as antioxidants in aged garlic extract. There is evidence showing the importance of oxidative stress in endothelial dysfunction. In the present study, we examined whether DDC and DDDC enhance endothelial cell function in vitro. Cell adhesion assay was performed using THP-1 monocyte and human umbilical vein endothelial cells (HUVECs) which were activated by lipopolysaccharide (LPS) or advanced glycation end products (AGEs)-BSA. Cellular ELISA method was used for the evaluation of vascular cell adhesion molecule 1 (VCAM-1) expression on HUVECs. DDC and DDDC suppressed the adhesion of THP-1 to HUVECs which was activated by LPS or AGEs-BSA. DDC and DDDC also inhibited VCAM-1 expression induced by LPS or AGEs-BSA, but DDDC was less effective than DDC. In addition, the inhibitory effect of DDC on VCAM-1 expression involved suppressing JNK/c-Jun pathway rather than NF-κB pathway. DDC has an inhibitory effect on VCAM-1 expression via JNK pathway in endothelial cells and therefore may serve as a novel pharmacological agent to improve endothelial dysfunction.

Magnesium lithospermate B, an active extract of Salvia miltiorrhiza, mediates sGC/cGMP/PKG translocation in experimental vasospasm

Background. Soluble guanylyl cyclases (sGCs) and Ras homolog gene family, member A (rhoA)/Ras homolog gene family kinase(rho-kinase) plays a role in vascular smooth muscle relaxation in subarachnoid hemorrhage (SAH). It is of interest to examine the effect of MLB on rhoA/ROCK and sGC/cGMP/PKG expression. Methods. A rodent SAH model was employed. Tissue samples were for sGCα1, sGCβ1, PKG, rhoA, ROCK (Western blot), and cGMP (ELISA) measurement. Results. MLB morphologically improved convolution of the internal elastic lamina, distortion of endothelial wall, and necrosis of the smooth muscle in the SAH rats. Expressed cGMP, sGCα1, sGCβ1, and PKG in the SAH groups were reduced (P < 0.01), and MLB precondition significantly induced cGMP, sGCα1, sGCβ1, and PKG. L-NAME reversed the vasodilation effect of MLB, reduced the bioexpression of PKG and cGMP (P < 0.01), and tends to reduce sGCα1 level and induce rhoA, ROCK level in MLB precondition + SAH groups. Conclusion. These results demonstrate that sGC/cGMP/PKG and NO/ET pathways play pivotal roles in SAH-induced vasospasm. Through activating sGC/cGMP/PKG pathway and partially by inactivating rho-kinase in a NO-dependent mechanism, MLB shows promise to be an effective strategy for the treatment of this disease entity.

Tanshinone II a protects against lipopolysaccharides-induced endothelial cell injury via Rho/Rho kinase pathway

OBJECTIVE

To test whether tanshinone II A (Tan II A), a highly valued herb derivative to treat vascular diseases in Chinese medicine, could protect endothelial cells from bacterial endotoxin (lipopolysaccharides, LPS)-induced endothelial injury.

METHODS

Endothelial cell injury was induced by treating human umbilical vein endothelial cells (HUVECs) with 0.2 μg/mL LPS for 24 h. Y27632 and valsartan were used as positive controls. The effects of tanshinone II A on the LPS-induced cell viability and apoptosis rate of HUVECs were tested by flow cytometry, cell migration by transwell, adhesion by a 96-well plate pre-coated with vitronectin and cytoskeleton reorganization by immunofluorescence assay. Rho/Rho kinase (ROCK) pathway-associated gene and protein expression were examined by microarray assay; quantitative real-time polymerase chain reaction and Western blotting were used to confirm the changes observed by microarray.

RESULTS

Tan II A improved cell viability, suppressed apoptosis and protected cells from LPS-induced reductions in cell migration and adhesion at a comparable magnitude to that of Y27632 and valsartan. Tan II A, Y27632 and valsartan also normalized LPS-induced actomyosin contraction and vinculin protein aggregation. A microarray assay revealed increased levels of fibronectin, integrin A5 (ITG A5), Ras homolog gene family member A (RhoA), myosin light chain phosphatase, phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K, or PIP2 in Western blotting), focal adhesion kinase, vascular endothelial growth factor and vascular endothelial growth factor receptor 2 in the damaged HUVECs, which were attenuated to different degrees by Tan II A, Y27632 and valsartan.

CONCLUSION

Tan II A exerted a strong protective effect on HUVECs, and the mechanism was caused, at least in part, by a blockade in the Rho/ROCK pathway, presumably through the down-regulation of ITG A5.

The globalization of traditional medicine in northern peru: from shamanism to molecules

Northern Peru represents the center of the Andean "health axis," with roots going back to traditional practices of Cupisnique culture (1000 BC). For more than a decade of research, semistructured interviews were conducted with healers, collectors, and sellers of medicinal plants. In addition, bioassays were carried out to evaluate the efficacy and toxicity of plants found. Most of the 510 species encountered were native to Peru (83%). Fifty percent of the plants used in colonial times have disappeared from the pharmacopoeia. Market vendors specialized either on common and exotic plants, plants for common ailments, and plants only used by healers or on plants with magical purposes. Over 974 preparations with up to 29 different ingredients were used to treat 164 health conditions. Almost 65% of the medicinal plants were applied in these mixtures. Antibacterial activity was confirmed in most plants used for infections. Twenty-four percent of the aqueous extracts and 76% of the ethanolic extracts showed toxicity. Traditional preparation methods take this into account when choosing the appropriate solvent for the preparation of a remedy. The increasing demand for medicinal species did not increase the cultivation of medicinal plants. Most species are wild collected, causing doubts about the sustainability of trade.

The Rho/Rho-associated protein kinase inhibitor fasudil in the protection of endothelial cells against advanced glycation end products through the nuclear factor κB pathway

Accumulating evidence has demonstrated that the Rho/Rho-associated protein kinase (Rho/ROCK) and nuclear factor κB (NF-κB) signaling pathways are involved in the pathogenesis of diabetic vascular injury. In this study, we investigated the beneficial effects of fasudil, a ROCK inhibitor, on vascular endothelial injury induced by advanced glycation end products (AGEs) in vitro. Human umbilical vein endothelial cells (HUVECs) were stimulated with AGEs and AGEs plus fasudil in various concentrations for different time periods. Monocyte-endothelial cell adhesion, vascular cell adhesion molecule-1 (VCAM-1) and monocyte chemoattractant protein-1 (MCP-1) expression, protein expression and activation of Rho/ROCK, activation of NF-κB and reactive oxygen species (ROS) production were evaluated. Fasudil suppressed AGE-induced monocyte-endothelial adhesion. Fasudil also reduced the mRNA and protein expression of VCAM-1 and MCP-1 in a concentration- and time-dependent manner. Moreover, increases in the protein levels of Rho/ROCK and ROCK activity mediated by AGEs were inhibited by the addition of fasudil. Additionally, fasudil attenuated AGE-induced NF-κB-dependent transcriptional activity and inhibition of NF-κB (IκB) phosphorylation. ROS production induced by AGEs was also reduced by fasudil in HUVECs. The results suggest that ROCK inhibition may protect the vascular endothelium against AGE-induced monocyte-endothelial adhesion in vitro through the reduction of ROS generation and the downregulation of NF-κB signaling. Thus, ROCK inhibition may be a novel therapeutic approach for the treatment of vascular complications in diabetes.

Inhibition of high glucose-induced inflammatory response and macrophage infiltration by a novel curcumin derivative prevents renal injury in diabetic rats

BACKGROUND AND PURPOSE

Inflammation is involved in the development and/or progression of many diseases including diabetic complications. Investigations on novel anti-inflammatory agents may offer new approaches for the prevention of diabetic nephropathy. Our previous bioscreening of synthetic analogues of curcumin revealed C66 as a novel anti-inflammatory compound against LPS challenge in macrophages. In this study, we hypothesized that C66 affects high glucose (HG)-induced inflammation profiles in vitro and in vivo and then prevents renal injury in diabetic rats via its anti-inflammatory actions.

EXPERIMENTAL APPROACH

Primary peritoneal macrophages (MPM), prepared from C57BL/6 mice, were treated with HG in the presence or absence of C66. Diabetes was induced in Sprague-Dawley rats with streptozotocin, and the effects of C66 (0.2, 1.0 or 5.0 mg·kg(-1) ), administered daily for 6 weeks, on plasma TNF-α levels and expression of inflammatory genes in the kidney were assessed.

KEY RESULTS

Pretreatment of MPMs with C66 reduced HG-stimulated production of TNF-α and NO, inhibited HG-induced IL-1β, TNF-α, IL-6, IL-12, COX-2 and iNOS mRNA transcription, and the activation of JNK/NF-kB signalling. In vivo, C66 inhibited the increased plasma TNF-α levels and renal inflammatory gene expression, improved histological abnormalities and fibrosis of diabetic kidney, but did not affect the hyperglycaemia in these diabetic rats.

CONCLUSIONS AND IMPLICATIONS

The anti-inflammatory effects of C66 are mediated by inhibiting HG-induced activation of the JNK/NF-κB pathway, rather than by reducing blood glucose in diabetic rats. This novel compound is a potential anti-inflammatory agent and might be beneficial for the prevention of diabetic nephropathy.

Attenuation of high-glucose-induced inflammatory response by a novel curcumin derivative B06 contributes to its protection from diabetic pathogenic changes in rat kidney and heart

There is increasing evidence indicating that inflammatory processes are involved in the development and progression of diabetic complications. However, effective anti-inflammatory treatments for patients who have diabetic complications have yet been practically identified. Curcumin is a main component of Curcuma longa with numerous pharmacological activities. Previously, we synthesized a novel curcumin analogue (B06) that exhibited an improved pharmacokinetic and enhanced anti-inflammatory activity compared to curcumin. The present study aimed to test the hypothesis that B06 may reduce high-glucose-induced inflammation and inflammation-mediated diabetic complications. In vitro, pretreatment with B06 at a concentration of 5 μM significantly reduced the high-glucose-induced overexpression of inflammatory cytokines in macrophages. This anti-inflammatory activity of B06 is associated with its inhibition of c-Jun N-terminal kinase/nuclear factor κB activation. In vivo, despite that B06 administration at 0.2 mg · kg(-1) · d(-1) for 6 weeks did not affect the blood glucose profile of diabetic rats, the B06-treated animals displayed significant decreases in inflammatory mediators in the serum, kidney, and heart and renal macrophage infiltration. This was accompanied with an attenuation of diabetes-induced structural and functional abnormalities in the kidney and heart. Taken together, these data suggest that the novel derivative B06 might be a potential therapeutic agent for diabetic complications via an anti-inflammatory mechanism and support the potential application in diabetic complication therapy via anti-inflammatory strategy.

ROCK inhibitor fasudil attenuated high glucose-induced MCP-1 and VCAM-1 expression and monocyte-endothelial cell adhesion

Background

Previous studies suggested that the RhoA/ROCK pathway may contribute to vascular complications in diabetes. The present study was designed to investigate whether ROCK inhibitor fasudil could prevent high glucose-induced monocyte-endothelial cells adhesion, and whether this was related to fasudil effects on vascular endothelial cell expression of chemotactic factors, vascular cell adhesion molecule-1 (VCAM-1) and monocyte chemoattractant protein-1 (MCP-1).

Methods

HUVECs were stimulated with high glucose (HG) or HG + fasudil in different concentration or different time. Monocyte-endothelial cell adhesion was determined using fluorescence-labeled monocytes. The mRNA and protein expression of VCAM-1 and MCP-1 were measured using real-time PCR and western blot. The protein levels of RhoA, ROCKI and p-MYPT were determined using western blot analysis. ELISA was employed to measure the expression of soluble VCAM-1 and MCP-1 in cell supernatants and human serum samples.

Results

Fasudil significantly suppressed HG-induced adhesion of THP-1 to HUVECs. Fasudil reduced Rho/ROCK activity (as indicated by lower p-MYPT/MYPT ratio), and prevented HG induced increases in VCAM-1 and MCP-1 mRNA and protein levels. Fasudil also decreased MCP-1 concentration in HUVEC supernatants, but increased sVCAM-1 shedding into the media. In human diabetic subjects, 2 weeks of fasudil treatment significantly decreased serum MCP-1 level from 27.9 ± 10.6 pg/ml to 13.8 ± 7.0 pg/ml (P < 0.05), while sVCAM-1 increased from 23.2 ± 7.5 ng/ml to 39.7 ± 5.6 ng/ml after fasudil treatment (P < 0.05).

Conclusions

Treatment with the Rho/ROCK pathway inhibitor fasudil attenuated HG-induced monocyte-endothelial cell adhesion, possibly by reducing endothelial expression of VCAM-1 and MCP-1. These results suggest inhibition of Rho/ROCK signaling may have therapeutic potential in preventing diabetes associated vascular inflammation and atherogenesis.

Prunella vulgaris suppresses HG-induced vascular inflammation via Nrf2/HO-1/eNOS activation

Vascular inflammation is an important factor which can promote diabetic complications. In this study, the inhibitory effects of aqueous extract from Prunella vulgaris (APV) on high glucose (HG)-induced expression of cell adhesion molecules in human umbilical vein endothelial cells (HUVEC) are reported. APV decreased HG-induced expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin. APV also dose-dependently inhibited HG-induced adhesion of HL-60 monocytic cells. APV suppressed p65 NF-κB activation in HG-treated cells. APV significantly inhibited the formation of intracellular reactive oxygen species (ROS). HG-stimulated HUVEC secreted gelatinases, however, APV inhibited it. APV induced Akt phosphorylation as well as activation of heme oxygenase-1 (HO-1), eNOS, and nuclear factor E2-related factor 2 (Nrf2), which may protect vascular inflammation caused by HG. In conclusion, APV exerts anti-inflammatory effect via inhibition of ROS/NF-κB pathway by inducing HO-1 and eNOS expression mediated by Nrf2, thereby suggesting that Prunella vulgaris may be a possible therapeutic approach to the inhibition of diabetic vascular diseases.

Evaluation and discovery of novel synthetic chalcone derivatives as anti-inflammatory agents

Major anti-inflammatory agents, steroids and cyclooxygenase, were proved to have serious side effects. Here, a series of chalcone derivatives were synthesized and screened for anti-inflammatory activities. QSAR study revealed that the presence of electron-withdrawing groups in B-ring and electron-donating groups in A-ring of chalcones was important for inhibition of LPS-induced IL-6 expression. Further, compounds 22, 23, 26, 40, and 47 inhibited TNF-α and IL-6 release in a dose-dependent manner and decreased LPS-induced TNF-α, IL-1β, IL-6, IL-12, and COX-2 mRNA production. Mechanistically, compounds 23 and 26 interfered with JNK/NF-κB signaling and dose-dependently prevented ERK and p38 activation. In addition, 23 and 26 exhibited a significant protection against LPS-induced death and were able to block high glucose-activated cytokine profiles in macrophages. Together, these data show a series of anti-inflammatory chalcones with potential therapeutic effects in inflammatory diseases.

Evaluation of antidiabetic potential of selected traditional Chinese medicines in STZ-induced diabetic mice

AIMS

Traditional Chinese medicine (TCM) has been used for treating complex chronic diseases owing to their fewer side-effects, better patient tolerance and relatively less cost. The present work was carried out to study the anti-diabetic efficacy and mechanisms of 34 TCMs.

MATERIALS AND METHODS

Streptozotocin (STZ)-diabetic mice were orally administrated with corresponding herbal solution once a day for 4 weeks. At the end of experiment, the level of plasma glucose, malondialdehyde (MDA), the activity of superoxide dismutase (SOD) and the serum aldose reductase (AR) were determined, the effects of TCM extract on α-glucosidase and angiotensin-converting enzyme (ACE) in vitro were also evaluated.

RESULTS

13 out of the 34 herbs showed a statistically significant plasma glucose lowering action compared with the diabetic control group. Biochemical analysis revealed that Atractylodes macrocephala, Codonopsis pilosula, Dioscorea opposite, Flos lonicerae and Pueraria lobata may retard the progression of diabetes via reduce the blood glucose level and prevent the increase of AR activity. Other tested herbs, such as Ramulus cinnamomi, Cinnamomum cassia, and Eucommia ulmoides, showed the antidiabetic ability by either prevent the decrease in SOD activity or suppress the increase of MDA. Zymologic assay reveals that Pueraria lobata and Anemarrhena asphodeloides showed the highest inhibition against α-glucosidase and ACE respectively. Interestingly, the post-treatment glucose levels and AR activity were positively correlated with kidney/body weight of 34 herbs treated diabetic mice (p = 0.02, 0.04 respectively).

CONCLUSIONS

Several potential antidiabetic herbs derived from Chinese traditional pharmacopeia such as Dioscorea opposite, Pueraria lobata, Codonopsis pilosula and Ramulus cinnamomi, have been found to exert a beneficial action on diabetes and diabetic complications via multi-mechanisms.

Differential modulation of angiogenesis by advanced glycation end products

Divergent angiogenic responses occur in different organs in a diabetic state. Many of the pathological effects were mediated by the advanced glycation end products (AGEs) of non-enzymatically glycated molecules. Investigations were carried out using different angiogenic model systems to examine whether the angiogenic response to AGEs is influenced by the cellular microenvironment. AGE-albumin increased angiogenesis in chick chorioallantoic membrane (CAM). It also increased sprouting in rat aortic rings and the expression of angiogenic markers CD31 and E-selectin and the angiogenic growth factor, vascular endothelial growth factor (VEGF) in human umbilical vein endothelial cells (HUVECs) in culture, suggesting a proangiogenic effect. But in a serum-supplemented condition, AGE-albumin inhibited aortic sprouting and expression of angiogenic markers and VEGF production by HUVECs, suggesting an antiangiogenic effect in the presence of serum. Blocking of the AGE effect by the antioxidants, N-acetyl cysteine and ascorbic acid, suggested that the AGE effect involved oxidant stress. Reversal of the AGE effect by LY 294 002, an inhibitor of the Akt pathway and increased phosphorylation of Akt in cells maintained in serum-free medium, suggested the involvement of the Akt pathway in mediating the AGE effect; such an effect was absent in a serum-supplemented condition. These opposing effects of AGE-albumin on angiogenesis in the presence and absence of serum suggested that the AGE accumulated in a hyperglycemic condition can affect angiogenesis depending on the microenvironment of the cells.

Anti-Inflammatory effect of Buddleja officinalis on vascular inflammation in human umbilical vein endothelial cells

Vascular inflammation process has been suggested to be an important risk factor in the initiation and development of atherosclerosis. In this study, we investigated whether and by what mechanisms an aqueous extract of Buddleja officinalis (ABO) inhibited the expressions of cellular adhesion molecules, which are relevant to inflammation and atherosclerosis. Pretreatment of human umbilical vein endothelial cells (HUVEC) with ABO (1-10 microg/ml) for 18 hours dose-dependently inhibited TNF-alpha-induced adhesion U937 monocytic cells, as well as mRNA and protein expressions of vascular cell adhesion molecule-1 (VCAM-1), and intercellular cell adhesion molecule-1 (ICAM-1). Pretreatment with ABO also blocked TNF-alpha-induced ROS formation. Nuclear factor-kappa B (NF-kappaB) is required in the transcription of these adhesion molecule genes. Western blot analysis revealed that ABO inhibits the translocation of the p65 subunit of NF-kappaB to the nucleus. ABO inhibited the TNF-alpha-induced degradation of IkappaB-alpha, an inhibitor of NF-kappaB, by inhibiting the phosphorylation of IkappaB-alpha in HUVEC. Taken together, ABO could reduce cytokine-induced endothelial adhesiveness throughout down-regulating intracellular ROS production, NF-kappaB, and adhesion molecule expression in HUVEC, suggesting that the natural herb Buddleja officinalis may have potential implications in atherosclerosis.

Geniposide inhibits high glucose-induced cell adhesion through the NF-kappaB signaling pathway in human umbilical vein endothelial cells

AIM

To investigate whether geniposide, an iridoid glucoside extracted from gardenia jasminoides ellis fruits, inhibits cell adhesion to human umbilical vein endothelial cells (HUVECs) induced by high glucose and its underlying mechanisms.

METHODS

HUVECs were isolated from human umbilical cords and cultured. The adhesion of monocytes to HUVECs was determined using fluorescence-labeled monocytes. The mRNA and protein levels of vascular cell adhesion molecule-1 (VCAM-1) and endothelial selectin (E-selectin) were measured using real-time RT-PCR and ELISA. Reactive oxygen species (ROS) production was measured using a fluorescent probe. The amounts of nuclear factor-kappa B (NF-kappaB) and inhibitory factor of NF-kappaB (IkappaB) were determined using Western blot analysis. The translocation of NF-kappaB from the cytoplasm to the nucleus was determined using immunofluorescence.

RESULTS

Geniposide (10-20 mumol/L) inhibited high glucose (33 mmol/L)-induced adhesion of monocytes to HUVECs in a dose-dependent manner. This compound (5-40 mumol/L) also inhibited high glucose-induced expression of VCAM-1 and E-selectin at the gene and protein levels. Furthermore, geniposide (5-20 micromol/L) decreased ROS production and prevented IkappaB degradation in the cytoplasm and NF-kappaB translocation from the cytoplasm to the nucleus in HUVECs.

CONCLUSION

Geniposide inhibits the adhesion of monocytes to HUVECs and the expression of CAMs induced by high glucose, suggesting that the compound may represent a new treatment for diabetic vascular injury. The mechanism underlying this inhibitory effect may be related to the inhibition of ROS overproduction and NF-kappaB signaling pathway activation by geniposide.

Buddleja officinalis suppresses high glucose-induced vascular smooth muscle cell proliferation: role of mitogen-activated protein kinases, nuclear factor-kappaB and matrix metalloproteinases

Diabetes mellitus is a well-established risk factor for vascular diseases caused by atherosclerosis. In the development of diabetic atherogenesis, vascular smooth muscle cell proliferation is recognized as a key event. Thus, we aimed to investigate whether an ethanol extract of Buddleja officinalis (EBO) suppresses high glucose-induced proliferation in primary cultured human aortic smooth muscle cells (HASMC). [(3)H]-thymidine incorporation revealed that incubation of HASMC with a high concentration of glucose (25 mmol/L) increased cell proliferation. The expression levels of cell cycle protein were also increased by treatment with high glucose concentration. Pretreatment of HASMC with EBO significantly attenuated the increase of high glucose-induced cell proliferation as well as p38 mitogen-activated protein kinases (MAPK) and JNK phosphorylation. EBO suppressed high glucose-induced matrix metalloproteinase (MMP)-9 activity in a dose-dependent manner. In addition, EBO suppressed nuclear factor-kappaB (NF-kappaB) nuclear translocation and transcriptional activity in high glucose conditions. Taken together, the present data suggest that EBO could suppress high glucose-induced atherosclerotic processes through inhibition of p38, JNK, NF-kappaB and MMP signal pathways in HASMC.