Roasted licorice extracts dampen high glucose-induced mesangial hyperplasia and matrix deposition through blocking Akt activation and TGF-beta signaling.

Diabetic nephropathy (DN) characterized as nephrotic syndrome and diffuse glomerulosclerosis can cause renal failure and end-stage kidney disease. Expansion of mesangial matrix around capillaries in the kidney glomeruli is a prominent feature of DN. This study investigated whether licorice extracts inhibited mesangial cell (MC) proliferation and matrix accumulation induced by high glucose (HG). Human renal MC were cultured in media containing 5.5 mM glucose plus 27.5 mM mannitol as an osmotic control or 33 mM glucose for 3 d in the presence of water or ethanol extracts from raw licorice (LW, LE) or roasted licorice (RLW, RLE). Non-polar components including glycyrrhetic acid were elevated during licorice roasting, whereas polar components soluble in water extracts were diminished. Exposure of cells to HG caused significant increases in collagen IV secretion and connective tissue growth factor (CTGF) expression, which was appeased by RLW and RLE at transcriptional levels. The inhibitory potency was high in the order of RLE > or = RLW > or = LE > > LW. Non-polar glycyrrhetic acid but not glycyrrhizin retarded HG-stimulated mesangial matrix deposition through diminishing CTGF expression. In addition, RLW and RLE but not LW modulated membrane type matrix metalloproteinase-1 (MT-1 MMP) expression, MMP-2 activity and tissue inhibitor of MMP-2 (TIMP-2), which facilitated the degradation of mesangial matrix. Furthermore, the augmented expression of CTGF and TIMP-2 in HG-exposed cells was mediated by Akt activation and TGF-beta/Smad signaling through PKCbeta2-responsive signaling pathways. However, HG-down-regulated MT-1 MMP expression was independent of activation of ERK1/2 and Akt when using their inhibitors of DB98059 (ERK1/2) and LY294002 (Akt) alone or in combination. These results demonstrate that extracts from roasted licorice may be highly potent therapeutic agents for the prevention and treatment of mesangial fibrosis and glomerulosclerosis leading to diabetes nephropathy due to longstanding diabetes mellitus.

An outbreak of skin and soft tissue infection caused by Mycobacterium abscessus following acupuncture.

Although outbreaks of Mycobacterium abscessus infection have been reported, none of these reports has identified the potential sources of infection and modes of transmission. In April 2008, we identified and investigated an outbreak of M. abscessus skin and soft tissue infections following acupuncture among the patients who visited an oriental medical clinic. Active surveillance of patients who had visited the clinic was conducted to define the extent of the outbreak. Environmental cultures and a case-control study were performed to elucidate the source of infection and mode of transmission. From 1002 patients interviewed, 109 patients were identified as having suffered M. abscessus skin and soft tissue infections at acupuncture sites. A single strain of M. abscessus was isolated from the wounds of 31 patients and nine environmental samples, including a diluted glutaraldehyde solution. The case-control study revealed that a higher numbers of visits to the clinic for acupuncture (adjusted OR (aOR) 20.12; 95% CI 4.34-93.35) and the use of interferential current therapy or low-frequency therapy (aOR 36.12; 95% CI 5.54-235.44) were associated with the development of M. abscessus infection. The contaminated diluted glutaraldehyde solution that was used to disinfect the physical therapy devices may have been the source of the outbreak of M. abscessus infection in the 109 patients who underwent acupuncture.

Antimetastatic and antitumor effects of benzoquinonoid AC7-1 from Ardisia crispa.

An antimetastatic and cytostatic substance, termed AC7-1, was isolated from Ardisia crispa and identified as a benzoquinonoid compound, 2-methoxy-6-tridecyl-1,4-benzoquinone. It was originally characterized as the potent PAF (platelet-activating factor) receptor-binding antagonist with nonspecific antiplatelet effects on platelet aggregation induced by various agonists including PAF, ADP, thrombin and collagen. The nonspecific antiaggregatory properties of AC7-1 drew our interest given its possible relationship in integrin receptor-binding antagonistic activity. The integrin receptor plays an important role in metastasis and thrombosis as the cell surface transmembrane protein. Based on the aforementioned facts, the antimetastatic activities of AC7-1 were examined using various in vitro and in vivo metastasis assays. AC7-1 strongly blocked B16-F10 melanoma cell adhesion to extracellular matrix (ECM) and B16-F10 melanoma cell invasion. AC7-1 also remarkably inhibited pulmonary metastasis and tumor growth in vivo. AC7-1 inhibited B16-F10 melanoma cell adhesion to only specific synthetic peptides including RGDS. These findings suggest that antimetastatic activities of AC7-1 can be caused by blocking integrin-mediated adherence. We found AC7-1 to be a potential candidate for the development of a new antimetastatic drug.

Biological and pharmacological effects of pinusolide, a novel platelet activating factor antagonist.

Pinusolide, a potent platelet activating factor (PAF) receptor binding antagonist, inhibited PAF-induced aggregation of rabbit platelets with an IC50 value of 5 microM, whereas no inhibitory effects on the aggregation induced by ADP, thrombin, and collagen were observed. Pinusolide protected the mice from PAF-induced lethality with ED50 values of 1.1 mg/kg, i.v. and 69 mg/kg, p.o. Topically given pinusolide at 2 mg/ear effectively inhibited croton oil induced mouse ear edema. All the pinusolide treated ears recovered to normal healthy appearance in a sharp contrast to totally necrotized untreated ears. These results indicated that pinusolide is a potent and specific PAF antagonist in all experimental models as shown in vitro, in vivo, and in animal tests.

Oxidative stress-induced apoptosis prevented by Trolox.

The ability of oxidative stress to induce apoptosis (programmed cell death), and the effect of Trolox, a water soluble vitamin E analog, on this induction were studied in vitro in mouse thymocytes. Cells were exposed to oxidative stress by treating them with 0.5-10 microM hydrogen peroxide (H2O2) for 10 min, in phosphate-buffered saline supplemented with 0.1 mM ferrous sulfate. Cells were resuspended in RPMI 1640 medium with 10% serum and incubated at 37 degrees C under 5% CO2 in air. Electron microscopic studies revealed morphological changes characteristic of apoptosis in H2O2-treated cells. H2O2 treatment fragmented the DNA in a manner typical of apoptotic cells, producing a ladder pattern of 200 base pair increments upon agarose gel electrophoresis. The percentage of DNA fragmentation (determined fluorometrically) increased with increasing doses of H2O2 and postexposure incubation times. Pre- or posttreatment of cells with Trolox reduced H2O2-induced DNA fragmentation to control levels and below. The results indicate that oxidative stress induces apoptosis in thymocytes, and this induction can be prevented by Trolox, a powerful inhibitor of membrane damage.