Anti-inflammatory and anti-osteoarthritis effect of Mollugo pentaphylla extract.

CONTEXT: Mollugo pentaphylla L. (Molluginaceae) extract (MPE) has been reported to have anti-inflammatory effect on MSU-induced gouty arthritis in a mouse model. OBJECTIVE: This study examined the anti-inflammatory activities of an MPE in vitro and anti-osteoarthritis effects on monosodium iodoacetate (MIA)-induced osteoarthritis (OA) in vivo. MATERIALS AND METHODS: The dried whole plants of M. pentaphylla were extracted with 70% ethanol under reflux. The anti-inflammatory effect of MPE was evaluated in vitro in lipopolysaccharide (LPS)-treated RAW264.7 cells. The anti-osteoarthritic effect of MPE was investigated in a Sprague-Dawley rat model of MIA-induced OA. Each seven male rats were orally administered MPE (75, 150 or 300 mg/kg) or the positive control drug indomethacin (1 mg/kg) 3 days before MIA injection and once daily for 11 days thereafter. After the treatment with MPE, no evidence of systemic adverse effects was observed in any study group. RESULTS: MPE exhibited anti-inflammatory activity via inhibition of the production of NO (57.8%), PGE2 (97.1%) and IL-6 (93.2%) in LPS-treated RAW264.7 cells at 200 µg/mL. In addition, MPE suppressed IL-1ß (60.9%), TNF-α (37.9%) and IL- 6 (40.9%) production and suppressed the synthesis of MMP-2, MMP-9 and COX-2 in the MIA-induced OA rat model. CONCLUSIONS: These results demonstrate that MPE exerts potent anti-inflammatory activities and protects cartilage in an OA rat model. This might be a potential candidate for therapeutic OA treatment.

Differential SUMOylation of LXRalpha and LXRbeta mediates transrepression of STAT1 inflammatory signaling in IFN-gamma-stimulated brain astrocytes.

To unravel the roles of LXRs in inflammation and immunity, we examined the function of LXRs in development of IFN-gamma-mediated inflammation using cultured rat brain astrocytes. LXR ligands inhibit neither STAT1 phosphorylation nor STAT1 translocation to the nucleus but, rather, inhibit STAT1 binding to promoters and the expression of IRF1, TNFalpha, and IL-6, downstream effectors of STAT1 action. Immunoprecipitation data revealed that LXRbeta formed a trimer with PIAS1-pSTAT1, whereas LXRalpha formed a trimer with HDAC4-pSTAT1, mediated by direct ligand binding to the LXR proteins. In line with the fact that both PIAS1 and HDAC4 belong to the SUMO E3 ligase family, LXRbeta and LXRalpha were SUMO-conjugated by PIAS1 or HDAC4, respectively, and SUMOylation was blocked by transient transfection of appropriate individual siRNAs, reversing LXR-induced suppression of IRF1 and TNFalpha expression. Together, our data show that SUMOylation is required for the suppression of STAT1-dependent inflammatory responses by LXRs in IFN-gamma-stimulated brain astrocytes.

Effects of Mollugo pentaphylla extract on monosodium urate crystal-induced gouty arthritis in mice.

BACKGROUND: Gout is an inflammatory condition induced by the deposition of monosodium urate (MSU) crystals in joints and soft tissues, and it can lead to acute or chronic arthritis. MSU are pro-inflammatory stimuli that can initiate, amplify and sustain an intense inflammatory response. In this study, we evaluated the anti-inflammatory effect of an extract of Mollugo pentaphylla (MPE) on MSU-induced gouty arthritis in a mouse model. METHOD: An MSU crystal suspension (4 mg/50 µL) was injected intradermally into the right paw. The mice were orally administered MPE (150 mg/kg or 300 mg/kg) or the positive control drug colchicine (1 mg/kg) 1 h before the MSU crystals were injected and then once daily for 3 days. The effects of MPE included inflammatory paw edema and pain upon weight-bearing activity, and we evaluated the inflammatory cytokine expression and paw tissue inflammation-related gene expression. RESULTS: MPE suppressed inflammatory paw edema and pain in the MSU-induced mice. MPE showed anti-inflammatory activity by inhibiting the production of TNF-α, interleukin (IL)-1ß, NLRP3 inflammasome and NF-κB. CONCLUSION: These results suggest that MPE has potent anti-inflammatory activities and may be useful as a therapeutic agent against gouty arthritis.

Inhibitory effects of Ponciri Fructus on testosterone-induced benign prostatic hyperplasia in rats.

BACKGROUND: Benign prostatic hyperplasia (BPH) is non-cancerous condition of enlargement of the prostate, a common occurrence in older men. The immature fruits of Poncirus trifoliata (L.) Rafinesque (Rutaceae), Ponciri Fructus are widely used in traditional oriental medicine for the therapy of various diseases. However, little is known about the mechanism underlying the pathogenesis of BPH. In the present study, we investigated the protective effects of a Ponciri Fructus extract (PFE) on the development of BPH in a in a rat model of BPH induced by testosterone propionate (TP). METHODS: Male Sprague Dawley rats were used as a model of BPH after its induction by daily subcutaneous injections of TP/corn oil, for a period of four weeks. PFE was administrated daily 1 h before TP/corn oil injection by oral gavage at a dose level of 200 mg/kg during the 4 weeks of TP/corn oil injections. All rats were sacrificed at the end of the experiment, we measured the relative prostate weight, the levels of testosterone and dihydrotestosterone (DHT), histological changes, activities of antioxidant enzymes (catalase, glutathione peroxidase, glutathione reductase, and superoxide dismutase), and expression of proliferating cell nuclear antigen (PCNA). In addition, we also measured the inhibition (%) of 5α-reductase in the prostatic tissue. RESULTS: Our findings indicate that PFE significantly inhibited the development of BPH; decreased the relative prostate weight, the level of testosterone and DHT in serum and prostatic tissue, prostatic hyperplasia, expression of PCNA, and increased the antioxidant enzymes. Moreover, PFE showed a weak inhibitory activity on 5α-reductase. CONCLUSIONS: These results suggest that PFE may be used as a therapeutic agent for BPH via antiproliferative and antioxidant effects.

Anti-inflammatory effect and action mechanisms of traditional herbal formula Gamisoyo-san in RAW 264.7 macrophages.

BACKGROUND: Gamisoyo-san (GMSYS) is a traditional herbal formula used to treat insomnia, dysmenorrhea, and infertility in Korea. The purpose of this study was to investigate the anti-inflammatory effect and action mechanisms of GMSYS in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. METHODS: The anti-inflammatory effects of GMSYS were investigated using nitric oxide (NO) assay and ELISAs for prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6). The anti-inflammatory action mechanisms of GMSYS were evaluated using Western blotting for inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and activation of nuclear transcription factor kappa B (NF-κB) and mitogen-activated protein kinases (MAPKs). RESULTS: GMSYS significantly inhibited the LPS-induced production of NO, PGE2, TNF-α, and IL-6 compared with the vehicle-treated cells. GMSYS consistently downregulated the expression of iNOS and COX-2 mRNA induced by LPS. In addition, pretreatment with GMSYS suppressed the LPS-induced activation of NF-κB and MAPKs such as p38, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK). CONCLUSIONS: Our results indicate that the anti-inflammatory effects of GMSYS in RAW 264.7 macrophages are associated with inhibition of the release of inflammatory mediators and cytokines through the suppression of MAPK and NF-κB activation. These findings suggest that GMSYS may be a useful therapeutic candidate for the prevention or treatment of inflammatory diseases.

Gyeji-tang water extract exerts anti-inflammatory activity through inhibition of ERK and NF-κB pathways in lipopolysaccharide-stimulated RAW 264.7 cells.

BACKGROUND: Gyeji-tang (GJT, Guizhi Tang in Chinese, Keishi-to in Japanese) is a traditional herbal decoction composed of 5 medicinal herbs. GJT has been used to treat the common cold, headaches, and fever in Asian countries including Korea, China, and Japan. In the present study, we investigated the inhibitory effect of a water extract of GJT on inflammatory response using the murine macrophage cell line, RAW 264.7. METHODS: RAW 264.7 macrophages were treated with lipopolysaccharide (LPS) to upregulate inflammatory genes. Cells were pretreated with various concentrations of GJT for 4 h and stimulated with LPS for an additional 20 h. Productions of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), cyclooxygenase-2 (COX-2), and prostaglandin E2 (PGE2) were measured by enzyme-linked immunosorbent assays (ELISAs). Protein expressions of heme oxygenase (HO)-1, extracellular signal-regulated kinase (ERK), and nuclear factor kappa-B (NF-κB) were analyzed by immunoblotting. RESULTS: Treatment with the GJT extract enhanced expression of HO-1 in macrophages without cytotoxicity. GJT extract significantly inhibited proinflammatory cytokines TNF-α and IL-6 in LPS-stimulated cells. GJT suppressed LPS-induced COX-2 expression, leading to a decrease in COX-2-derived PGE2 level. In addition, GJT extract prevented phosphorylation of ERK and NF-κB translocalization to the nucleus in LPS-treated RAW 264.7 cells. CONCLUSION: These data suggest that GJT has anti-inflammatory possibly through blocking ERK and NF-κB signaling pathways.

Simultaneous quantification and antiatherosclerosis effect of the traditional Korean medicine, Hwangryunhaedok-tang.

BACKGROUND: Hwangryunhaedok-tang (HHT) is a traditional herbal medicine that is used for the treatment of fever, inflammation, gastritis, and hypertension. In this study, we performed simultaneous determination of the five components, geniposide (1), baicalin (2), coptisine (3), palmatine (4), and berberine (5) in HHT by using a high-performance liquid chromatography-photodiode array (HPLC-PDA) analysis. We also evaluated the antioxidative activity of HHT and compounds 1-5 by measuring their effects on low-density lipoprotein (LDL) oxidation and antiproliferative abilities in vascular smooth muscle cells (VSMCs). METHODS: Five compounds were separated within 40 min by using a Gemini C18 column (temp. 35°C; two-component gradient elution; flow rate 1.0 mL/min; detector 240 and 277 nm). The activities of HHT and compounds 1-5 were tested with the radical scavengers 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt and 2,2-diphenyl-1-picrylhydrazyl, in thiobarbituric acid reactive substance assays, and in relative electrophoretic mobility assays using CuSO4-induced LDL oxidation systems. The antiproliferative effects of samples on platelet-derived growth factor (PDGF)-induced VSMC proliferation were studied by using a cell proliferation assay. RESULTS: Regression analysis of the five major compounds showed good linearity (r (2) ≥ 0.9997) in different concentration ranges. The recoveries of the five compounds were in the range 86.31-110.78%, with relative standard deviations below 2.1%; those of intra- and interday precision were 0.04-3.78% and 0.04-1.69%, respectively. HHT reduced the oxidation properties of LDL induced by CuSO4 and inhibited cell proliferation in PDGF-treated VSMCs. Among the five components, compound 2 could effectively suppress LDL oxidation and PDGF-induced VSMC proliferation. CONCLUSIONS: The established HPLC-PDA method will help to improve quality control of HHT. The results demonstrate that HHT has antiatherosclerotic activity and that it functions by modulating LDL oxidation and VSMC proliferation. The effects of HHT may be attributed, at least I part, to compound 2.

Alantolactone from Saussurea lappa Exerts Antiinflammatory Effects by Inhibiting Chemokine Production and STAT1 Phosphorylation in TNF-α and IFN-γ-induced in HaCaT cells.

Skin inflammation is the most common condition seen in dermatology practice and can be caused by various allergic reactions and certain toxins or chemicals. In the present study, we investigated the antiinflammatory effects of Saussurea lappa, a medicinal herb, and its marker compounds alantolactone, caryophyllene, costic acid, costunolide, and dehydrocostuslactone in the HaCaT human keratinocyte cell line. HaCaT cells were stimulated with tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ), and treated with S. lappa or each of five marker compounds. Chemokine production and expression were analyzed by enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction, respectively. Phosphorylation of signal transducer and activator of transcription (STAT) 1 was determined by immunoblotting. Stimulation with TNF-α and IFN-γ significantly increased the production of the following chemokines: thymus-regulated and activation-regulated chemokine (TARC): regulated on activation, normal T-cell expressed and secreted (RANTES): macrophage-derived chemokine (MDC): and interleukin-8 (IL-8). By contrast, S. lappa and the five marker compounds significantly reduced the production of these chemokines by TNF-α and IFN-γ-treated cells. S. lappa and alantolactone suppressed the TNF-α and IFN-γ-stimulated increase in the phosphorylation of STAT1. Our results demonstrate that alantolactone from S. lappa suppresses TNF-α and IFN-γ-induced production of RANTES and IL-8 by blocking STAT1 phosphorylation in HaCaT cells.

Simultaneous quantification and inhibitory effect on LDL oxidation of the traditional Korean medicine, Leejung-tang.

BACKGROUND: Leejung-tang (LJT) is a traditional Korean herbal medicine for the treatment of gastrointestinal disorders. In this study, we performed quantification analysis of five marker components, liquiritin (1), ginsenoside Rg1 (2), ginsenoside Rb1 (3), glycyrrhizin (4), and 6-gingerol (5) in LJT using a high performance liquid chromatography-photodiode array (HPLC-PDA). In addition, we investigated the inhibitory effect on low-density lipoprotein (LDL) oxidation by the LJT sample. METHODS: Compounds 1-5 were separated within 35 min using a Gemini C18 column. The mobile phase used gradient elution with 1.0% (v/v) aqueous acetic acid (A) and 1.0% (v/v) acetic acid in acetonitrile (B). The flow rate was 1.0 mL/min and the detector was a photodiode array (PDA) set at 203 nm, 254 nm, and 280 nm. The inhibitory effect on LDL oxidation conduct an experiment on thiobarbituric acid reactive substance (TBARS) assay, relative electrophoretic mobility (REM) assay, and electrophoresis of ApoB fragmentation of LJT. RESULTS: Calibration curves of compounds 1-5 showed good linearity (r(2) ≥0.9995) in different concentration ranges. The recoveries of compounds 1-5 were in the range of 98.90-103.39%, with relative standard deviations (RSD) below 3.0%. The RSDs (%) of intra-day and inter-day precision were 0.10-1.08% and 0.29-1.87%, respectively. The inhibitory effect of LJT on Cu(2+)-induced LDL oxidation was defined by TBARS assay (IC50: 165.7 µg/mL) and REM of oxLDL (decrease of 50% at 127.7 µg/mL). Furthermore LJT reduced the fragmentation of ApoB of oxLDL in a dose-dependent manner. CONCLUSIONS: The established HPLC-PDA method will be helpful to improve quality control of LJT. In addition, LJT is a potential LDL oxidation inhibitor.

Acute oral toxicity of Insampaedok-san, a traditional herbal formula, in rats and its protective effects against ovalbumin-induced asthma via anti-inflammatory and antioxidant properties.

BACKGROUND: Insampaedok-san (ren-shen-bai-du-san in Chinese) is a traditional herbal formula widely used for the treatment of respiratory diseases in Korea and China. In this study, we investigated the acute oral toxicity of an Insampaedok-san water extract (ISSE) in rats and the antiasthmatic effects of ISSE and its mechanism in a model of asthma induced by ovalbumin (OVA) in mice. METHODS: In a safety study, ISSE was administrated orally to rats of both sexes at single doses of 0 and 5000 mg/kg. We observed body weight changes, mortality, clinical signs, and gross pathological findings. In vitro antioxidant activity of ISSE was measured using 2,2-diphenyl-2-picrylhydrazyl and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid radical scavenging methods. A model of asthma was established in mice by sensitization and challenge with OVA. We assessed the levels of type 2 T-helper cytokines, chemokines, and immunoglobulin levels, using enzyme-linked immunosorbent assays, and superoxide dismutase (SOD) activity using a kit. RESULTS: No adverse effects were observed in the acute ISSE toxicity study. ISSE showed potent free radical scavenging activity and inhibited the recruitment of inflammatory cells into the lung and mucus hypersecretion in OVA-challenged mice. ISSE significantly decreased levels of interleukin (IL)-4, IL-5, eotaxin, and OVA-specific immunoglobulin (Ig)E, and increased SOD activity. CONCLUSIONS: These results indicate that ISSE is safe for human consumption and its antiasthmatic effect is associated with the ability of ISSE to attenuate inflammation and oxidative stress.

Jaeumganghwa-Tang, a traditional herbal formula, improves muscle function and attenuates muscle loss in aged mice.

PURPOSE: Jaeumganghwa-Tang (JGT), a traditional herbal formula composed of 12 medicinal herbs, is used for the treatment of age-related diseases. In the present study, we investigated the effects of JGT on muscle mass and function in aged mice. METHODS: Young (5-month-old) and old (19-month-old) male C57BL/6 mice were divided into two groups each; one group received JGT (75 mg/d) and the other group received the vehicle for 6 weeks. At the end of the experimental period, muscle strength was examined using the wire hang test, and the tibialis anterior and gastrocnemius muscles were weighed. Muscle samples were further used for histological analysis to assess muscle damage, and the expression of transforming growth factor-beta was investigated via western blotting and immunohistochemistry. RESULTS: Our results showed that treatment of old mice with JGT improved muscle strength, increased skeletal muscle mass, alleviated muscle damage, and suppressed intramuscular expression of transforming growth factor-beta. CONCLUSION: In conclusion, JGT has beneficial effects on age-related loss of muscle mass and function. Thus, it might serve as a potential therapeutic agent for sarcopenia.

Synergistic Uric Acid-Lowering Effects of the Combination of Chrysanthemum indicum Linne Flower and Cinnamomum cassia (L.) J. Persl Bark Extracts.

Chrysanthemum indicum Linne flower (CF) and Cinnamomum cassia (L.) J. Persl bark (CB) extracts have served as the main ingredients in several prescriptions designed to treat hyperuricemia and gout in traditional Chinese and Korean medicine. However, little is known about the combination effects of a CF and CB (CC) mixture on hyperuricemia. In our study, we investigated the antihyperuricemic effects of CC mixture and the mechanisms underlying these effects in normal and potassium oxonate- (PO-) induced hyperuricemic rats. The CC mixture significantly decreased uric acid levels in normal and PO-induced hyperuricemic rats and showed the enhanced hypouricemic effect compared to CF or CB alone. Furthermore, the CC mixture increased renal uric acid excretion in PO-induced hyperuricemic rat. We found that CC mixture and its major components, chlorogenic acid, 3,4-dicaffeoylquinic acid (isochlorogenic acid), coumarin, cinnamaldehyde, trans-cinnamic acid, and o-methoxycinnamaldehyde, inhibit the activity of xanthine oxidase (XOD) in vitro. The CC mixture exerts antihyperuricemic effects accompanied partially by XOD activity inhibition. Therefore, the CC mixture may have potential as a treatment for hyperuricemia and gout.

Apigetrin from Scutellaria baicalensis Georgi Inhibits Neuroinflammation in BV-2 Microglia and Exerts Neuroprotective Effect in HT22 Hippocampal Cells.

Apigetrin is a flavonoid isolated from various herbal medicines such as Scutellaria baicalensis Georgi, Matricaria chamomilla, Stachys tibetica Vatke, and Teucrium gnaphalodes. In the present study, we investigated the inhibitory effects of apigetrin on neuroinflammation using the BV-2 microglia cell line. Our data revealed that apigetrin significantly reduced secretion and mRNA expression of inflammatory cytokines, tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), in lipopolysaccharide (LPS)-stimulated BV-2 mouse microglia. Apigetrin also significantly decreased LPS-mediated production of prostaglandin E2 (PGE2) level and nitric oxide (NO) production as well as expression of cyclooxygenase 2 (COX-2) and inducible nitric oxide synthase (iNOS) in BV-2 cells. In addition, apigetrin suppressed nuclear expression of nuclear factor kappa B (NF-κB) in LPS-stimulated BV-2 cells. Furthermore, apigetrin significantly impaired reactive oxygen species (ROS) generation and enhanced expression of antioxidant enzymes, hempxygenase 1 (HO-1) and nuclear factor-like 2 (Nrf2), in BV-2 cells. Apigetrin also increased 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, indicating antioxidative activity of apigetrin. Moreover, we found that apigetrin inhibited hydrogen peroxide (H2O2)-induced cell death in HT22 hippocampal cells. Overall, our findings indicate that apigetrin has inhibitory effects on neuroinflammation as well as antioxidation and neuroprotection, suggesting the potential prophylactic activity for neurodegenerative diseases through the inter-regulation of neuroinflammation, oxidative stress, and neuronal injury.

Anti­inflammatory and antioxidant activity of the traditional herbal formula Gwakhyangjeonggi­san via enhancement of heme oxygenase­1 expression in RAW264.7 macrophages.

Gwakhyangjeonggi­san (GHJGS) is a mixture of herbal plants, including Agastache rugosa, Perilla frutescens, Angelica dahurica, Areca catechu, Poria cocos, Magnolia officinalis, Atractylodes macrocephala, Citrus reticulata, Pinellia ternata, Platycodon grandiflorum, Glycyrrhiza uralensis, Ziziphus jujuba and Zingiber officinale. GHJGS has been used for treating diarrhea­predominant irritable bowel syndrome in traditional Korean medicine. In the present study, the anti­inflammatory and antioxidant effects of GHJGS were investigated using the RAW 264.7 murine macrophage cell line. GHJGS significantly reduced production of the proinflammatory cytokines, tumor necrosis factor­α, interleukin­6 and prostaglandin E2 in lipopolysaccharide (LPS)­stimulated macrophages. GHJGS markedly suppressed LPS­induced phosphorylation of mitogen­activated protein kinases, whereas it had no effect on nuclear factor­κB activation. Furthermore, GHJGS enhanced expression of heme oxygenase­1 and prevented the generation of reactive oxygen species in RAW 264.7 cells. These results indicate that GHJGS is a viable therapeutic agent against inflammation and oxidative stress­associated disorders.

Anti-adipogenic and antioxidant effects of the traditional Korean herbal formula Samchulgeonbi-tang: an in vitro study.

AIMS: Here we report in vitro anti-adipogenic and antioxidant effects of Samchulgeonbi-tang (SCGBT), a traditional Korean herbal formula. METHODS: 3T3-L1 preadipocytes were differentiated into adipocytes with or without SCGBT. After differentiation, we measured Oil Red O staining, glycerol-3-phosphate dehydrogenase (GPDH) activity and leptin production. In addition, its effect on scavenging activities of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radicals in in vitro systems. RESULTS: In differentiated 3T3-L1 adipocytes, SCGBT significantly inhibited lipid accumulation and triglyceride production, and mediated inactivation of GPDH, a major enzyme in the process of adipogenesis. Consistent with this, SCGBT stimulation significantly decreased the amount of leptin in 3T3-L1 adipose cells. Furthermore, SCGBT enhanced the scavenging activities on ABTS and DPPH radicals. The generation of malondialdehyde (MDA) during low-density lipoprotein (LDL) oxidation was significantly reduced by SCGBT treatment. Of interest, SCGBT extract inhibited reactive oxygen species (ROS) generation in 3T3-L1 adipocytes. CONCLUSION: Overall, our findings suggest that SCGBT has the potential for anti-adipogenic activity and antioxidant properties.

Extracts of Scutellariae Radix inhibit low-density lipoprotein oxidation and the lipopolysaccharide-induced macrophage inflammatory response.

Traditional herbal formulas made from Scutellariae Radix (SR), the root of Scutellaria baicalensis, have previously been used in the treatment of inflammatory diseases, such as atherosclerosis. The aim of the present study was to investigate the effects of SR on low-density lipoprotein (LDL) oxidation and inflammation in macrophages, which are early events in the development of atherosclerosis. High-performance liquid chromatography photo-diode array analysis was used to obtain a three-dimensional chromatogram of SR. The antioxidative effects of SR were evaluated by determining its scavenging activities against ABTS and DPPH radicals. The inhibitory effect of SR on LDL oxidation was examined using a thiobarbituric acid-reactive substance assay and a relative electrophoretic mobility assay. In addition, the anti-inflammatory effects of SR were evaluated in lipopolysaccharide (LPS)-induced RAW264.7 murine macrophage cells. The results showed that SR exhibited radical-scavenging activities in a dose-dependent manner; in addition, SR attenuated the Cu2+-induced oxidation of LDL as well as significantly inhibited nitric oxide (NO) production and inducible NO synthase (iNOS) expression in LPS-induced RAW264.7 cells. Furthermore, SR induced the protein expression of heme oxygenase-1 (HO-1) in RAW264.7 cells. In conclusion, the results of the present study demonstrated that SR decreased the oxidation of LDL and suppressed inflammatory responses in macrophages, which occurred at least in part via the induction of HO­1. These results therefore suggested that SR may be a potential therapeutic agent for the treatment of atherosclerosis.

Antioxidant and antiadipogenic activities of galkeun-tang, a traditional korean herbal formula.

Galkeun-tang (GKT; Galgen-tang in Chinese and Kakkon-to in Japanese), a traditional herbal formula, has been used for treatment of the common cold. Here, we report in vitro antioxidant and antiadipogenic effects of GKT. GKT increased the activities of scavenging 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. GKT also significantly reduced the malondialdehyde (MDA) generation during low-density lipoprotein (LDL) oxidation and the electrophoretic mobility of oxidized LDL, indicating inhibitory effects of GKT on Cu(2+)-mediated oxidation of LDL. Regarding antiadipogenic activity, GKT treatment significantly suppressed lipid accumulation, triglyceride production, and glycerol-3-phosphate dehydrogenase (GPDH) activity in differentiated 3T3-L1 adipocytes. Consistent with this, GKT significantly reduced the secretion of leptin, a major adipokine, in differentiated 3T3-L1 adipocytes. Overall, our findings suggest that GKT has the potential for antioxidative and antiadipogenic properties.

Accumulation of argpyrimidine, a methylglyoxal-derived advanced glycation end product, increases apoptosis of lens epithelial cells both in vitro and in vivo.

The formation of advanced glycation end products (AGEs) has been considered to be a potential causative factor of injury to lens epithelial cells (LECs). Damage of LECs is believed to contribute to cataract formation. The purpose of this study was to investigate the cytotoxic effect of AGEs on LECs both in vitro and in vivo. We examined the accumulation of argpyrimidine, a methylglyoxal-derived AGE, and the expression of apoptosis-related molecules including nuclear factor- kappaB (NF-κB), Bax, and Bcl-2 in the human LEC line HLE-B3 and in cataractous lenses of Zucker diabetic fatty (ZDF) rats, an animal model of type 2 diabetes. In cataractous lenses from twenty-oneweek- old ZDF rats, LEC apoptosis was markedly increased, and the accumulation of argpyrimidine as well as subsequent activation of NF-κB in LECs were significantly enhanced. The ratio of Bax to Bcl-2 protein levels was also increased. In addition, the accumulation of argpyrimidine triggered apoptosis in methylglyoxal- treated HLE-B3 cells. However, the presence of pyridoxamine (an AGEs inhibitor) and pyrrolidine dithiocarbamate (a NF-κB inhibitor) prevented apoptosis in HLE-B3 cells through the inhibition of argpyrimidine formation and the blockage of NF-κB nuclear translocalization, respectively. These results suggest that the cellular accumulation of argpyrimidine in LECs is NF-κB-dependent and pro-apoptotic.

Cytotoxic role of methylglyoxal in rat retinal pericytes: Involvement of a nuclear factor-kappaB and inducible nitric oxide synthase pathway.

Methylglyoxal (MGO), a cytotoxic metabolite, is produced from glycolysis. Elevated levels of MGO are observed in a number of diabetic complications, including retinopathy, nephropathy and cardiomyopathy. Loss of retinal pericyte, a hallmark of early diabetic retinal changes, leads to the development of formation of microaneurysms, retinal hemorrhages and neovasculization. Herein, we evaluated the cytotoxic role of MGO in retinal pericytes and further investigated the signaling pathway leading to cell death. Rat primary retinal pericytes were exposed to 400muM MGO for 6h. Retinal vessels were prepared from intravitreally MGO-injected rat eyes. We demonstrated apoptosis, nuclear factor-kappaB (NF-kappaB) activation and inducible nitric oxide synthase (iNOS) induction in cultured pericytes treated with MGO and MGO-injected retinal vessels. In MGO-treated pericytes, TUNEL-positive nuclei were markedly increased, and NF-kappaB was translocalized into the nuclei of pericytes, which paralleled the expression of iNOS. The treatment of pyrrolidine dithiocarbamate (an NF-kappaB inhibitor) or l-N6-(1-iminoethyl)-lysine (an iNOS inhibitor) prevented apoptosis of MGO-treated pericytes. In addition, in intravitreally MGO-injected rat eyes, TUNEL and caspase-3-positive pericytes were significantly increased, and activated NF-kappaB and iNOS were highly expressed. These results suggest that the increased expression of NF-kappaB and iNOS caused by MGO is involved in rat retinal pericyte apoptosis.

KIOM-79 prevents methyglyoxal-induced retinal pericyte apoptosis in vitro and in vivo.

AIMS OF STUDY: The purpose of this study was to investigate the protective effects of KIOM-79, a combination of four plant extracts, on retinal pericytes loss, which is one of the histopathological hallmarks of early diabetic retinopathy. MATERIALS AND METHODS: To investigate the protective effect of KIOM-79 on pericyte apoptosis, we have used methylglyoxal (MGO)-treated primary rat retinal pericytes and retinal vessels from intravitreally MGO-injected eyes. Primary rat retinal pericytes were exposed to 400 microM MGO for 6h with or without KIOM-79. 400 microM final intravitreal concentration of MGO with or without KIOM-79 (10 microg/ml final intravitreal concentration) were intravitreally injected into the right eyes of rats for 2 days. The left eyes were received 3mul of saline only. Retinal vessels were then isolated. We examined apoptosis, ROS productions, 8-OHdG in cultured rat retinal pericytes and retinal vessels. RESULTS: In CCK-8 assay and TUNEL staining, MGO-induced apoptosis of rat retinal pericytes was markedly inhibited by KIOM-79. KIOM-79 significantly reduced intracellular ROS productions and oxidative damage induced by MGO. In addition, the intravitreal injection of KIOM-79 prevented apoptosis of retinal microvascular cells, MGO accumulation and oxidative DNA damage in intravitreally MGO-injected eye. CONCLUSION: These observations suggest that KIOM-79 acts through an antioxidant mechanism to protect against oxidative stress-induced apoptosis in retinal pericytes.