Hyunsu Bae

Resveratrol stimulates glucose transport in C2C12 myotubes by activating AMP-activated protein kinase

trans-Resveratrol (t-RVT), a naturally occurring polyphenol found in Polygonum cuspidatum, grape, and red wine, has been reported to have anti- inflammatory, cardioprotective, and cancer chemopreventive properties. However antidiabetic effect of t-RVT has not yet been reported. In this study, we show that t-RVT increases glucose uptake in C2C12 myotubes by activating AMP-activated protein kinase (AMPK), uncovering an antidiabetic potential of t-RVT for the first time. AMPK plays a central role in the regulation of glucose and lipid metabolism, and hence it is considered a novel therapeutic target for metabolic syndrome such as type 2 diabetes. t-RVT significantly induced glucose uptake in C2C12 cells, via AMPK activation, but not a phosphatidylinositol-3 kinase (PI-3 kinase) signal pathway. The induced glucose uptake was attenuated by pretreatment with a pharmacological inhibitor for AMPK, indicating that the effect of t-RVT primarily depends on AMPK activation. However, in the presence of insulin, t-RVT also potentiated the effect of insulin on glucose uptake via AMPK activation, which led to further activation of PI-3 kinase/Akt signal pathway.

Anti-inflammatory effects of Scutellaria baicalensis water extract on LPS-activated RAW 264.7 macrophages

AIM OF THE STUDY The root of Scutellaria baicalensis Georgi (Labiatae), also known as Scutellariae Radix, possesses anticancer, antiviral, and anti-inflammatory properties. And it is one of the most widespread herbal remedies used in Oriental medicine. In the present study, we investigated the effects of Scutellariae Radix water extract (SR) on proinflammatory mediators secreted from lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. MATERIAL AND METHODS Cell viability was assessed by MTT assay and nitric oxide (NO) concentration in the cultured medium was determined by the Griess reaction. Various Cytokines released from LPS-induced Raw 264.7 cells were measured in the cell culture supernatants using a multiplex bead array assay based on xMAP technology. RESULTS We found that SR significantly inhibited the production of NO, interleukin (IL)-3, IL-6, IL-10, IL-12p40, IL-17, interferon-inducible protein (IP)-10, keratinocyte-derived chemokine (KC), and vascular endothelial growth factor (VEGF) in LPS-induced RAW 264.7 cells at the concentrations of 25, 50, 100, 200 microg/ml (p<0.05). CONCLUSIONS These results suggest that SR has anti-inflammatory activity related with its inhibition of NO, cytokine, chemokine, and growth factor production in macrophages.

Acupuncture and immune modulation

Acupuncture is probably the most popular alternative therapy practiced in the United States, Europe and many Asian countries. It has been applied clinically for more than 5 thousand years according to the ancient oriental medical theory. A great deal of acupuncture research has been achieved, with particular efforts toward understanding the pain control effects. In addition to the analgesic effect of acupuncture, an increasing number of studies have demonstrated that acupuncture treatment can control autonomic nerve system functions such as blood pressure regulation, sphincter Oddi relaxation, and immune modulation. Although only a limited number of controlled studies have assessed the efficacy of acupuncture, increasing clinical evidences support that EA treatment is effective for various immunological diseases including allergic disorders, infections, autoimmune diseases and immunodifficiency-syndromes. This review will address the mechanism of acupuncture in modulating various immune responses and the relationship between acupuncture mediated immune regulation and neurological involvement.

CD4+CD25+ regulatory T cells attenuate cisplatin-induced nephrotoxicity in mice

Nephrotoxicity limits the use of cisplatin, a widely used chemotherapeutic agent for treatment of various malignancies. Overall, CD4+ T cells mediate cisplatin-induced renal injury; however, the CD4+CD25+ regulatory T-cell subset (CD4+CD25+ Treg) has broad suppressive effects on many different cell types. In this study, we determined whether CD4+CD25+ Treg cells had protective effects against cisplatin-induced acute renal injury in nu/nu mice that lack mature T cells. In these mice, there was marked attenuation of the decreased survival, renal dysfunction and tubular injury, renal tumor necrosis factor-α, and interleukin-1β cytokine levels. Furthermore, renal macrophage accumulation was reduced in CD4+CD25+ Treg cell-adoptive transferred nu/nu mice compared with control mice. Infusion of CD4+CD25+Treg cells into wild-type Balb/c mice reduced serum blood urea nitrogen and creatinine levels equivalent to those in nu/nu mice and extended their survival time after cisplatin injection. In contrast, depletion of CD4+CD25+ Treg cells in wild-type mice exacerbated kidney injury after cisplatin administration. Transcription factor Foxp3-positive cells (Treg cells) were detected in the kidneys of nu/nu mice after cisplatin injection. Our results suggest that CD4+CD25+ Treg cells directly affect cisplatin nephrotoxicity and their modulation represents an additional treatment strategy.

Original ArticleCD4+CD25+ regulatory T cells attenuate cisplatin-induced nephrotoxicity in mice

Nephrotoxicity limits the use of cisplatin, a widely used chemotherapeutic agent for treatment of various malignancies. Overall, CD4+ T cells mediate cisplatin-induced renal injury; however, the CD4+CD25+ regulatory T-cell subset (CD4+CD25+ Treg) has broad suppressive effects on many different cell types. In this study, we determined whether CD4+CD25+ Treg cells had protective effects against cisplatin-induced acute renal injury in nu/nu mice that lack mature T cells. In these mice, there was marked attenuation of the decreased survival, renal dysfunction and tubular injury, renal tumor necrosis factor-α, and interleukin-1β cytokine levels. Furthermore, renal macrophage accumulation was reduced in CD4+CD25+ Treg cell-adoptive transferred nu/nu mice compared with control mice. Infusion of CD4+CD25+Treg cells into wild-type Balb/c mice reduced serum blood urea nitrogen and creatinine levels equivalent to those in nu/nu mice and extended their survival time after cisplatin injection. In contrast, depletion of CD4+CD25+ Treg cells in wild-type mice exacerbated kidney injury after cisplatin administration. Transcription factor Foxp3-positive cells (Treg cells) were detected in the kidneys of nu/nu mice after cisplatin injection. Our results suggest that CD4+CD25+ Treg cells directly affect cisplatin nephrotoxicity and their modulation represents an additional treatment strategy.

The antioxidant effects of genistein are associated with AMP-activated protein kinase activation and PTEN induction in prostate cancer cells.

Epidemiological evidence suggests a lower incidence of prostate cancer in Asian countries, where soy products are more frequently consumed than in Western countries, indicating that isoflavones from soy have chemopreventive activities in prostate cells. Here, we tested the effects of the soy isoflavone genistein on antioxidant enzymes in DU145 prostate cancer cells. Genistein significantly decreased reactive oxygen species levels and induced the expression of the antioxidant enzymes manganese (Mn) superoxide dismutase (SOD) and catalase, which were associated with AMP-activated protein kinase (AMPK) and phosphatase and tensin homolog deleted from chromosome 10 (PTEN) pathways. The induced expression of catalase, MnSOD, and PTEN were attenuated by pretreatment with a pharmacological inhibitor for AMPK, indicating the effects of genistein primarily depend on AMPK. Furthermore, PTEN is essential for genistein activity, as shown by PTEN transfection in PTEN-deficient PC3 cells. Thus, genistein induces antioxidant enzymes through AMPK activation and increased PTEN expression.

Antiangiogenic phytochemicals and medicinal herbs.

Medicinal herbs and their phytochemicals are potential novel leads for developing antiangiogenic drugs. This review aims to assess the current status of research with medicinal herbs and their phytochemicals for the development of antiangiogenic agents for cancer and other angiogenesis‐related diseases including inflammation, diabetic retinopathy, endometriosis and obesity. Most studies reviewed have focused on vascular endothelial growth factor (VEGF)/vascular endothelial growth factor receptor 2 (VEGFR‐2) signaling for endothelial response processes and have led to the identification of many potential antiangiogenic agents. Since human clinical trials with antiangiogenic modalities targeting VEGF/VEGFR‐2 signaling have shown limited efficacy and occasional toxic side effects, screening strategies for herbal phytochemicals based on other signaling pathways important for cancer‐endothelial and stromal crosstalks should be emphasized in the future. Copyright

The association of cholecystokinin-A receptor expression with the responsiveness of electroacupuncture analgesic effects in rat.

The purpose of this study is to determine whether the level of cholecystokinin (CCK) receptor expression causes the differences between the responder and non-responder to electroacupuncture mediated analgesic effects. Male Sprague-Dawley rats were stimulated at the Zusanli (ST36) acupoint in the absence of any anesthetics and holders. The tail flick latency test was performed to quantify analgesic effects and then the responder and non-responder groups were classified. The hypothalamus of each group was dissected and RNA was purified. The amount of mRNA expression of CCK-A and CCK-B receptors was determined by reverse transcription-polymerase chain reaction. The results show that CCK-A receptors are significantly more expressed in non-responders than responders, whereas CCK-B receptor expression is similar in both groups.

Effects of Atractylodes macrocephala Koidzumi rhizome on 3T3-L1 adipogenesis and an animal model of obesity

ETHNOPHARMACOLOGICAL RELEVANCE Atractylodes macrocephala Koidzumi (AMK) is an herbal medicine traditionally used for treatment of abdominal pain, gastrointestinal disease, obesity, and related complications. AIM OF THE STUDY We investigated the effects and molecular mechanism of AMK rhizome water extract on 3T3-L1 adipogenesis and an animal model of obesity. MATERIALS AND METHODS To study the effect of AMK on adipogenesis in vitro, differentiating 3T3-L1 cells were treated every two days with AMK at various concentrations (1-25μg/ml) for eight days. Oil Red O staining was performed to determine the lipid accumulation in 3T3-L1 cells. To elucidate the inhibitory mechanism of AMK on adipogenesis, phosphorylation levels of Akt and expression of perilipin, were analyzed by Western blotting. AMK was administered orally to high fat diet (HFD)-induced obese rats to confirm its effect in vivo. RESULTS AMK inhibited 3T3-L1 adipocyte differentiation in a dose-dependent manner without cellular toxicity. Phospho-Akt expression was highly decreased by AMK treatment, whereas there was no significant change in perilipin expression. AMK administration significantly reduced the body weight of rats fed a HFD. Plasma triglyceride levels were significantly lower in the AMK-treated HFD group than those in the HFD control group or normal diet (ND) group, although serum total, HDL- and LDL-cholesterol levels did not differ between the groups. CONCLUSION These results demonstrate an inhibitory effect of AMK on adipogenesis through reduction of an adipogenic factor, phospho-Akt. AMK had a beneficial effect, reducing body weight gain in a HFD-induced animal model of obesity.

Constituents of Asarum sieboldii with Inhibitory Activity on Lipopolysaccharide (LPS)‐Induced NO Production in BV‐2 Microglial Cells

Bioassay‐guided fractionation of the root extract of Asarum sieboldii led to the isolation of the four active compounds (−)‐sesamin (1), (2E,4E,8Z,10E)‐N‐(2‐methylpropyl)dodeca‐2,4,8,10‐tetraenamide (2), kakuol (3), and ‘3,4,5‐trimethoxytoluene’ (=1,2,3‐trimethoxy‐5‐methylbenzene; 4), in terms of inhibition of lipopolysaccharide (LPS)‐induced nitric oxide (NO) production. Compounds 1–4 showed potent inhibition of NO production, with IC50 values in the low nanomolar‐to‐micromolar range. Also isolated were the known compounds methylkakuol (5), ‘3,5‐dimethoxytoluene’, safrole, asaricin, methyleugenol, and (−)‐asarinin, which were found to be inactive in the above assay. Among the ten known isolates, compounds 1, 2, and 5 were found for the first time in this plant.