Jung Joo Yoon

Protective role of betulinic acid on TNF-α-induced cell adhesion molecules in vascular endothelial cells

Vascular inflammation is an important event in the development of vascular diseases such as tumor progression and atherosclerosis. In the present study, betulinic acid (BA) treatment was found to show potent inhibitory effect on vascular inflammation process by TNF-alpha in human umbilical vein endothelial cells (HUVEC). Pretreatment of HUVEC with BA was blocked TNF-alpha induced expression level of cell adhesion molecules such as intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), endothelial cell selectin (E-selectin) as well as gelatinase in TNF-alpha-activated HUVEC in a dose-dependent manner. When preincubated with BA, the adhesion of HL-60 cells to TNF-alpha-induced HUVEC was significantly decreased in a concentration-dependent manner. TNF-alpha-induced intracellular ROS was markedly decreased by pretreatment with BA. Furthermore, BA significantly inhibited the translocation and transcriptional activity of NF-kappaB increased by TNF-alpha. In conclusion, these results suggested a vascular protective role of BA via inhibition of ROS and NF-kappaB activation in HUVEC.

Effect of Poria cocos on hypertonic stress-induced water channel expression and apoptosis in renal collecting duct cells

ETHNOPHARMACOLOGICAL RELEVANCE A major physiological role of the kidney is to regulate body water and urine concentration. Aquaporin-2 (AQP2), a family of water channels, plays an important role in the urinary concentrating process and regulation of water balance in the kidney. The dried sclerotia of Poria cocos Wolf has been known to have a diuretic effect and used for the treatment of chronic edema and nephrosis. AIM OF THE STUDY This study was conducted to evaluate the inhibitory effect of the sclerotia of Poria cocos (WPC) on hypertonic stress-induced AQP2 expression and apoptosis in inner medullary collecting duct cell lines (IMCD-3). MATERIALS AND METHODS Hypertonic stress was induced by 175mM NaCl. Inhibitory effect of WPC on hypertonic stress-induced AQP2 expression and apoptosis were determined by western blot, RT-PCR, and immunofluorescence. RESULTS Hypertonic stress (175mM NaCl) increased in the levels of AQP2 expression by hypertonicity in IMCD-3 cells. WPC attenuated the hypertonicity-induced increase in protein and mRNA levels of AQP2 in a concentration-dependent manner. Pretreatment with WPC attenuated hypertonicity-induced cell death. Hypertonicity increased serum- and glucocorticoid-inducible protein kinase (Sgk1) phosphorylation, however, WPC attenuated the hypertonicity-induced Sgk1 activation. Tonicity-responsive enhancer binding protein (TonEBP) mRNA was also recovered by WPC under hypertonic stress. Pretreatment with WPC presented the similar effect of PKA inhibitor which decreased hypertonic stress-induced AQP2 expression. Hypertonicity increased cAMP levels and the changes were blocked by WPC. On the other hand, hypertonic stress-induced Bax or caspase-3 expression was decreased by WPC, resulting in anti-apoptotic effect. CONCLUSIONS These results provided evidence that the beneficial effect of WPC in water balance against in vitro hypertonic stress of renal collecting ducts. In addition, WPC exhibits anti-apoptotic property response to hypertonic stress. Thus, these data suggests that WPC has benefit for the therapeutic approach to the inhibition of renal disorder.

Betulinic acid inhibits high glucose‐induced vascular smooth muscle cells proliferation and migration

The proliferation of vascular smooth muscle cells may perform a crucial role in the pathogenesis of diabetic vascular disease. The principal objective of this study was to determine the effects of betulinic acid (BA) on human aortic smooth muscle cell (HASMC) proliferation induced by high glucose (HG). In this study, [3H]‐thymidine incorporation under 25 mM HG was accelerated significantly as compared with 5.5 mM glucose, and this increase was inhibited significantly by BA treatment. We utilized Western blotting analysis to evaluate the effects of BA on cell‐cycle regulatory proteins. HG induced the expression of cyclins/CDKs and reduced the expression of p21waf1/cip1/p27kip1. However, BA also attenuated the expression of HG‐induced cell‐cycle regulatory proteins. The results of gelatin zymography demonstrated that the HG‐treated HASMC secreted gelatinases, probably including MMP‐2/‐9, which may be involved in the invasion and migration of HASMC. Additionally, BA suppressed the protein and mRNA expression levels of MMP‐2/‐9 in a dose‐dependent manner. BA inhibited the production of HG‐induced hydrogen peroxide (H2O2) and the formation of DCF‐sensitive intracellular reactive oxygen species (ROS). Further, BA suppressed the nuclear translocation and phosphorylation of IκB‐α of NF‐κB under HG conditions. Our results showed that BA exerts multiple effects on HG‐induced HASMC proliferation and migration, including the inhibition of both MMP‐2 and MMP‐9 transcription, protein activity, and the downregulation of ROS/NF‐κB signaling, thereby suggesting that BA may be a possible therapeutic approach to the inhibition of diabetic vascular disease. J. Cell. Biochem. 111: 1501–1511, 2010.

Portulaca oleracea Ameliorates Diabetic Vascular Inflammation and Endothelial Dysfunction in db/db Mice

Type 2 diabetes is associated with significantly accelerated rates of micro- and macrovascular complications such as diabetic vascular inflammation and endothelial dysfunction. In the present study, we investigated the protective effect of the aqueous extract of Portulaca oleracea L. (AP), an edible plant used as a folk medicine, on diabetic vascular complications. The db/db mice were treated with AP (300 mg/kg/day, p.o.) for 10 weeks, and AP treatment markedly lowered blood glucose, plasma triglyceride, plasma level of LDL-cholesterol, and systolic blood pressure in diabetic db/db mice. Furthermore, AP significantly increased plasma level of HDL-cholesterol and insulin level. The impairment of ACh- and SNP-induced vascular relaxation of aortic rings were ameliorated by AP treatment in diabetic db/db mice. This study also showed that overexpression of VCAM-1, ICAM-1, E-selectin, MMP-2, and ET-1 were observed in aortic tissues of untreated db/db mice, which were significantly suppressed by treatment with AP. We also found that the insulin immunoreactivity of the pancreatic islets remarkably increased in AP treated db/db mice compared with untreated db/db mice. Taken together, AP suppresses hyperglycemia and diabetic vascular inflammation, and prevents the development of diabetic endothelial dysfunction for the development of diabetes and its vascular complications.

An aqueous extract of Portulaca oleracea ameliorates diabetic nephropathy through suppression of renal fibrosis and inflammation in diabetic db/db mice.

Diabetic nephropathy is one of the most common microvascular complications of diabetes and the leading cause of end-stage renal disease. In the present study, we investigated the renoprotective effect of the aqueous extract of Portulaca oleracea (AP) on diabetic nephropathy accelerated by renal fibrosis and inflammation in type 2 diabetic db/db mice. The mice were treated with AP (300 mg/kg/day, p.o.) for ten weeks to examine the long-term effects on diabetic nephropathy and renal dysfunction. We found that AP treatment markedly lowered blood glucose to 412 ± 11.4 mg/dl and plasma creatinine level to 2.3 ± 0.8 mg/dl compared to db/db mice (p < 0.05, p < 0.01, respectively). This study also showed that treatment with AP significantly decreased water intake and urine volume in diabetic db/db mice (p < 0.05). In immunohistological study, the renal expression of transforming growth factor-β1 (TGF-β1), advanced glycation end products (AGE), and intercellular adhesion molecule (ICAM)-1 markedly increased in the renal cortex of untreated db/db mice (p < 0.01). In contrast, AP treatment significantly reduced these expressions to 50 ± 2.1%, 48 ± 2.8%, 61 ± 1.1%, respectively (p < 0.01). Furthermore, NF-κB p65 activation in renal tissues markedly increased in untreated db/db mice, which was significantly suppressed by AP treatment. Taken together, these findings suggest that AP attenuates diabetic nephropathy through inhibition of renal fibrosis and inflammation in db/db mice.

Inhibitory effect of Thuja orientalis on TNF-α-induced vascular inflammation

Vascular inflammation is involved in the initiation and progression of vascular diseases including atherosclerosis. While conducting in vitro screening of 600 medicinal plant extracts, an aqueous extract of Thuja orientalis (ATO) was found to exhibit antiinflammatory activity in human umbilical vein endothelial cells (HUVEC). In the current study, the antiinflammatory activity of ATO and possible mechanisms for this were investigated in HUVEC. Preincubation with ATO (20 μg/mL) suppressed tumor necrosis factor‐α (TNF‐α)‐induced expression of adhesion molecules including intercellular adhesion molecule‐1 (ICAM‐1), vascular cell adhesion molecule‐1 (VCAM‐1) and E‐selectin at both the protein and mRNA levels. ATO also inhibited U937 monocyte adhesion to HUVEC stimulated by TNF‐α. In addition, ATO attenuated TNF‐α‐induced p65 NF‐κB translocation into the nucleus and phosphorylation of IκB‐α. Furthermore, ATO significantly inhibited TNF‐α‐induced intracellular reactive oxygen species (ROS) production. Overall, the present data suggest that ATO can suppress TNF‐α‐induced vascular inflammatory processes, possibly via inhibition of ROS and NF‐κB activation, in HUVEC. Copyright

Anti-diabetic atherosclerosis effect of Prunella vulgaris in db/db mice with type 2 diabetes.

Diabetes mellitus is the leading cause of vascular complications such as atherosclerosis. This study was designed to investigate whether Prunella vulgaris (APV) would inhibit diabetic atherosclerosis in db/db mice with type 2 diabetes. The db/db mice were treated with high fat/high cholesterol (HFHC) diet and an aqueous extract of APV (100 and 200 mg/kg/day) for eight weeks to examine the long-term effect on metabolic abnormalities and diabetic atherosclerosis. APV treatment markedly lowered blood glucose and systolic blood pressure. The db/db mice experienced an increase in blood urea nitrogen as well as a decrease of creatinine clearance, the latter of which was restored by treatment with APV. Treatment with APV markedly decreased total plasma cholesterol, triglyceride, and LDL-cholesterol and also increased the HDL-cholesterol. In addition, malondialdehyde and TGF-β1 were decreased by treatment of APV. On the other hand, total NO level was decreased in db/db mice. However, the NO level was increased by treatment with APV, suggesting an association with vascular dysfunction. Vascular relaxation of aortic rings by acetylcholine or SNP-inducement was ameliorated by APV in a dose-dependent manner. Damage of vascular intima and hypertrophic of media were observed in db/db mice; however its dysfunction was improved by the treatment of APV. APV treatment significantly reduced the aortic expressions of ICAM-1, VCAM-1, ET-1, and nitrotyrosine. Furthermore, expression of eNOS in aortic was remarkably increased by APV treatment. Taken together, APV suppressed hyperglycemia and diabetic vascular dysfunction in HFHC diet-db/db mice. The present data suggest that Prunella vulgaris may prevent development of diabetic atherosclerosis.

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.

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.

Fermented Red Ginseng Potentiates Improvement of Metabolic Dysfunction in Metabolic Syndrome Rat Models

Metabolic syndrome including obesity, dyslipidemia and hypertension is a cluster of risk factors of cardiovascular disease. Fermentation of medicinal herbs improves their pharmacological efficacy. Red ginseng (RG), a widely used traditional herbal medicine, was reported with anti-inflammatory and anti-oxidant activity. Aim in the present study was to investigate that the effects of fermented red ginseng (FRG) on a high-fructose (HF) diet induced metabolic disorders, and those effects were compared to RG and losartan. Animals were divided into four groups: a control group fed a regular diet and tap water, and fructose groups that were fed a 60% high-fructose (HF) diet with/without RG 250 mg/kg/day or FRG 250 mg/kg/day for eight weeks, respectively. Treatment with FRG significantly suppressed the increments of body weight, liver weight, epididymal fat weight and adipocyte size. Moreover, FRG significantly prevented the development of metabolic disturbances such as hyperlipidemia and hypertension. Staining with Oil-red-o demonstrated a marked increase of hepatic accumulation of triglycerides, and this increase was prevented by FRG. FRG ameliorated endothelial dysfunction by downregulation of endothelin-1 (ET-1) and adhesion molecules in the aorta. In addition, FRG induced markedly upregulation of Insulin receptor substrate 1 (IRS-1) and glucose transporter type 4 (Glut4) in the muscle. These results indicate that FRG ameliorates obesity, dyslipidemia, hypertension and fatty liver in HF diet rats. More favorable pharmacological effects on HF diet induced metabolic disorders were observed with FRG, compared to an equal dose of RG. These results showed that the pharmacological activity of RG was enhanced by fermentation. Taken together, fermentated red ginseng might be a beneficial therapeutic approach for metabolic syndrome.