Byung Hyuk Han

Hwangryunhaedoktang exerts anti-inflammation on LPS-induced NO production by suppressing MAPK and NF-κB activation in RAW264.7 macrophages

OBJECTIVE This study aimed to evaluate whether Hwangryunhaedoktang (HHT), a herbal compound, has an inhibitory effect on lipopolysaccharide (LPS)-induced inflammation in RAW264.7 macrophages. METHODS The effects of HHT were evaluated by confirming nitric oxide (NO) production and expression of inducible NO synthase (iNOS) and mitogen-activated protein kinases (MAPKs) in LPS-stimulated RAW264.7 macrophages via the Griess assay, Western blotting, and real-time reverse transcription quantitative polymerase chain reaction. Western blot analyses and luciferase assays were used to evaluate whether HHT has an effect on the phosphorylation and translocation of nuclear factor-κB (NF-κB). The secretion and expression of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were determined via enzyme-linked immunosorbent assay and Western blot analyses. RESULTS HHT suppressed LPS-induced NO production and expression of iNOS in a dose-dependent manner. Additionally, MAPKs activation was also attenuated via inhibition of phosphorylation of extracellular signal-regulated kinases 1/2, c-Jun N-terminal kinase and p38 which were related to inflammatory pathway. Furthermore, HHT also effectively attenuated NF-κB activation and its translocation to the nucleus, a process that is closely linked to inflammation. LPS normally induced the expression of inflammatory cytokines such as TNF-α and IL-6, but the secretion and expression of TNF-α and IL-6 were significantly attenuated by pretreating the cells with HHT. CONCLUSION HHT suppressed LPS-induced NO production by blocking the activation of NF-κB and MAPK signaling pathways in RAW264.7 macrophages. Furthermore, HHT may have an anti-inflammatory effect by suppressing the LPS-induced secretion of TNF-α and IL-6. Therefore, the traditional herbal formula HHT might be a useful potential therapeutic agent for inflammation.

Protective effect of betulinic acid on early atherosclerosis in diabetic apolipoprotein-E gene knockout mice

ABSTRACT Atherosclerosis, a chronic and progressive disease, is a leading cause of endothelial dysfunction, diabetes mellitus, hypertension, and hypercholesterolemia. Betulinic acid (BA), a pentacyclic triterpene, has been reported to have a variety of biological effects, including anti‐inflammatory and immunomodulatory properties. This study was designed to determine whether BA could prevent atherosclerosis in diabetic apolipoprotein‐E gene knockout (ApoE KO) mice. The mice were treated with BA for 12 weeks to examine its beneficial effects on atherosclerosis in ApoE KO mice. Male ApoE KO mice and age‐matched control group mice (C57BL/6Jms) were used as experimental systems and their systolic blood pressure, insulin resistance, and vascular inflammation were measured. BA‐treated ApoE KO mice showed lowered systolic blood pressure. The metabolic parameter showed that BA decreased blood urea nitrogen, triglyceride, and total cholesterol levels. Blood glucose, insulin, glucose tolerance results, and the homeostasis model assessment of insulin resistance (HOMA‐IR) index were found to be better in BA‐treated ApoE KO mice than untreated ApoE KO mice. Consistent with the change in lipid profiles, oil red O and H&E staining revealed that treatment with BA reduced atherosclerotic lesions such as roughened endothelial layers. BA ameliorated the reduction of endothelial nitric oxide synthase (eNOS) expression, leading to the inhibition of intracellular adhesion molecule 1 (ICAM‐1) and endothelin 1 (ET‐1) expression. These results suggest that BA may be useful in the treatment and prevention of early atherosclerosis via the attenuation of endothelial dysfunction in diabetic ApoE KO mice. Graphical abstract Figure. No caption available.

Vascular Protective Role of Samul-Tang in HUVECs: Involvement of Nrf2/HO-1 and NO

Samul-Tang (Si-Wu-Tang, SMT), composed of four medicinal herbs, is a well-known herbal formula treating hematological disorder or gynecologic disease. However, vascular protective effects of SMT and its molecular mechanisms on the vascular endothelium, known as the central spot of vascular inflammatory process, are not reported. The aim of this study was to investigate vascular protective effects of SMT water extract in human umbilical vein endothelial cells (HUVECs). Water extract of SMT was prepared and identified by HPLC-PDA analysis. Expression of cell adhesion molecules (CAMs) and heme oxygenase-1 (HO-1) and translocation of nuclear factor-kappa B (NF-κB) and nuclear factor-erythroid 2-related factor 2 (Nrf2) were determined by western blot. Nuclear localization of NF-κB and Nrf2 was visualized by immunofluorescence and DNA binding activity of NF-κB was measured. ROS production, HL-60 monocyte adhesion, and intracellular nitric oxide (NO) were also measured using a fluorescent indicator. SMT suppressed NF-κB translocation and activation as well as expression of CAMs, monocyte adhesion, and ROS production induced by TNF-α in HUVECs. SMT treated HUVECs showed upregulation of HO-1 and NO which are responsible for vascular protective action. Our study suggests that SMT, a traditionally used herbal formula, protects the vascular endothelium from inflammation and might be used as a promising vascular protective drug.

Ligustilide attenuates vascular inflammation and activates Nrf2/HO-1 induction and, NO synthesis in HUVECs

BACKGROUND Ligustilide is a bioactive phthalide derivative isolated from Cnidii Rhizoma (Cnidium officinale, rhizome) and Angelicae Gigantis Radix (Angelica gigas Nakai, root) which are both medicinal herbs used to treat circulatory disorders. Vascular endothelium is a central spot in developing cardiovascular diseases and chronic vascular inflammation might result in atherosclerosis development. PURPOSE We previously found out that a traditional herbal formula, Samul-Tang (Si-Wu-Tang, containing Cnidii Rhizoma and Angelicae Gigantis Radix), attenuated vascular inflammation in human umbilical vein endothelial cells (HUVECs). However, which compound was responsible for vascular protective action remained unclear. Here, we investigated vascular protective potential of an isolated single compound, (Z)-ligustilide. METHODS MTT assay, western blotting, immunofluorescence, electrophoretic mobility shift assay was performed. BCECF-AM, CM-H2DCFDA, DAF-FM diacetate were used as a fluorescent indicator. RESULTS Ligustilide suppressed HL-60 monocyte adhesion and CAMs (ICAM-1, VCAM-1, E-selectin) expression in HUVECs. Ligustilide significantly inhibited TNF-α-increased production of ROS and activated NF-κB signaling pathway. Also, ligustilide treated HUVECs exhibited significant HO-1 induction via Nrf2 nuclear translocation and endothelial NO synthesis. CONCLUSION Present study demonstrates that ligustilde attenuates vascular inflammation and activate defense system of endothelial cell. Ligustilide is a bioactive compound which might prevent cardiovascular complications such as thrombosis or atherosclerosis.

Prunella vulgaris Attenuates Diabetic Renal Injury by Suppressing Glomerular Fibrosis and Inflammation.

Diabetic nephropathy is both the most common complication and the leading cause of mortality associated with diabetes. Prunella vulgaris, a well-known traditional medicinal plant, is used for the cure of abscess, scrofula, hypertension and urinary diseases. This study confirmed whether an aqueous extract of Prunella vulgaris (APV) suppresses renal inflammation and fibrosis. In human mesangial cell (HMC), pretreatment of APV attenuated 25[Formula: see text]mM HG-induced suppressed TGF-[Formula: see text] and Smad-2/4 expression; it increased the expression level of Smad-7. Connective tissue growth factor (CTGF) and collagen IV, fibrosis biomarkers, were significantly decreased by APV. APV suppressed inflammatory factors such as intracellular cell adhesion molecule-1 (ICAM-1) and monocyte chemoattractant protein-1 (MCP-1). APV inhibited activation and translocation of nuclear factor kappa-B (NF-[Formula: see text]B) in HG-stimulated HMCs. Moreover, APV significantly improved HG-induced ROS in a dose-dependent manner. In diabetic rat models, APV significantly decreased blood glucose, blood urea nitrogen (BUN) and ameliorated plasma creatinine (PCr). APV reduced the PAS positivity staining intensity and basement membrane thickening in glomeruli of diabetic rats. Fibrosis related proteins such as collagen IV and TGF-[Formula: see text]1 were also inhibited by APV. These results suggest that APV has a significant protective effect against diabetic renal dysfunction including inflammation and fibrosis through disruption of the TGF-[Formula: see text]/Smad signaling. Therefore, APV may be useful in potential therapies that target glomerulonephritis and glomerulosclerosis, which lead to diabetic nephropathy.

Samul-Tang Regulates Cell Cycle and Migration of Vascular Smooth Muscle Cells against TNF-α Stimulation

Samul-Tang (SMT), consisting of four medicinal herbs, is a well-known herbal prescription treating hematological disorders related symptoms. Our previous study demonstrated that SMT attenuated inflammation of vascular endothelial cells. In condition of retained vascular dysfunction, vascular inflammation is initiated and results in activation of smooth muscle cells (SMCs). Activated SMCs lose control of cell cycle regulation and migrate into intima, resulting in formation of atheroma. Here, we further investigated whether SMT suppresses proliferation and migration of SMCs. SMT showed antiproliferative effects on SMCs by suppressing [3H]-thymidine incorporation against TNF-α stimulation. Underlying mechanisms of antiproliferative effects were found to be resulting from cell cycle regulation. SMT downregulated expression of cyclin D1-CDK4 and cyclin E-CDK2 complexes and upregulated p21waf1/cip1 and p27kip1. SMT also suppressed migration of SMCs against TNF-α stimulation. This is thought to have resulted from suppressing MMP2 and MMP9 expressions and ROS production. In summary, SMT attenuates abnormal migration of vascular smooth muscle cells via regulating cell cycle and suppressing MMPs expression and ROS production. Our study suggests that SMT, a traditionally used herbal formula, protects vascular smooth muscle cells and might be used as an antiatherosclerotic drug.

Inhibitory effect of brassinin on TNF‑α‑induced vascular inflammation in human umbilical vein endothelial cells

Brassinin, a phytoalexin firstly identified as a constituent of Chinese cabbage, has been demonstrated to exhibit antiproliferative effects on various cancer cell lines, by reducing reactive oxygen species (ROS) production via regulation of the antioxidant pathway. The present study aimed to explore the protective effects of brassinin in TNF‑α‑induced vascular inflammation in human umbilical vein endothelial cells (HUVECs). Pretreatment with brassinin significantly inhibited adhesion of U937 cells to TNF‑α‑induced HUVECs in a dose‑dependent manner. Brassinin treatment decreased the expression levels of cell adhesion molecules, including intracellular adhesion molecule‑1 (ICAM‑1), vascular cell adhesion molecule‑1 (VCAM‑1), and endothelial‑selectin (E‑selectin) following stimulation with TNF‑α in HUVECs. In addition, pretreatment with brassinin decreased the protein expression levels of nuclear factor (NF)‑κB p65 in the nucleus, suggesting that brassinin inhibited NF‑κB p65 nuclear translocation. Brassinin treatment also markedly decreased the mRNA expression levels of interleukin‑8 in a dose‑dependent manner. Finally, brassinin pretreatment significantly decreased TNF‑α‑induced intracellular reactive oxygen species (ROS) production in HUVECs compared with control. The present results therefore suggest that brassinin may serve as a potential therapeutic agent for atherosclerosis.