Topical Gynura procumbens as a Novel Therapeutic Improves Wound Healing in Diabetic Mice.

Nonhealing wounds are major socioeconomic challenges to healthcare systems worldwide. Therefore, there is a substantially unmet need to develop new drugs for wound healing. Gynura procumbens, a herb found in Southeast Asia, may be an effective therapeutic for nonhealing diabetic wounds. The aim of this study was to evaluate the efficacy of G. procumbens on wound healing in the diabetic milieu. G. procumbens extract was obtained using 95% ethanol and its components were determined by thin layer chromatography. Diabetes was induced in mice using streptozotocin. We found that G. procumbens extract contained stigmasterol, kaempferol and quercetin compounds. Topical application of G. procumbens on the wounded skin of diabetic mice accelerated wound healing and induced the expression of angiogenin, epidermal growth factor, fibroblast growth factor, transforming growth factor and vascular endothelial growth factor. Furthermore, G. procumbens promoted in vitro wound healing and enhanced the migration and/or proliferation of human endothelial cells, fibroblasts, keratinocytes and mast cells cultured in diabetic conditions. Finally, G. procumbens promoted vascular formation in the diabetic mice. To the best of our knowledge, this is the first study that evaluates in vivo wound healing activities of G. procumbens and activation of cells involved in wound healing process in diabetic conditions. The findings that G. procumbens accelerates wound healing and activates cells involved in the wound healing process suggest that G. procumbens might be an effective alternative therapeutic option for nonhealing diabetic wounds.

MD-2 is required for the full responsiveness of mast cells to LPS but not to PGN.

To address the role played by MD-2 in mast cell recognition of LPS, we examined bone marrow-derived mast cells (BMMCs) from MD-2 gene-targeted mice. BMMCs from MD-2-/- mice showed impaired cytokine production (TNF-alpha, IL-6, IL-13, and IL-1beta) in response to LPS from Escherichia coli, but not to peptidoglycan (PGN) from Staphylococcus aureus. In a mast cell-dependent acute septic model, MD-2 deficiency of mast cell resulted in significantly higher mortality due to defective neutrophil recruitment and the production of cytokines in the peritoneal cavity, which was similar to mice with TLR4-deficient mast cells. The TLR2-dependent activation of skin mast cells by PGN was not altered by the absence of MD-2 in vivo. Collectively, MD-2 is essential for the recognition of LPS by TLR4 but not for that of PGN by TLR2 of mast cells.

Safety and efficacy of saquinavir soft-gelatin capsules + zidovudine + optional lamivudine in pregnancy and prevention of vertical HIV transmission.

BACKGROUND: The treatment of HIV infection during pregnancy significantly and substantially reduces the risk of mother-to-child transmission. Although triple therapy is the standard of care for management of HIV infection in adults, the safety of many approved antiretroviral agents in pregnancy is not currently established. METHODOLOGY: An open-label pilot study conducted in Thailand and the UK of the safety of saquinavir soft-gel capsules 1200 mg three times daily administered in the second and third trimester of pregnancy in combination with local standard-of-care antiretroviral therapy. Infants received local standard-of-care antiretroviral therapy after delivery. Steady-state pharmacokinetics were performed in a subset of mothers at 4 weeks after the commencement of saquinavir therapy and paired samples collected from the mother and infant cord blood at delivery. RESULTS: Eighteen antiretroviral-naive pregnant women with a mean viral load of 4.2 log10 and CD4 cell count of 481/mm(3) were recruited. All patients received zidovudine and 3 (all in the UK) received lamivudine. There were no serious adverse events and no discontinuations due to adverse events. Viral load declined by 1.6 log10 at week 4 and was less than 400 copies/mL at delivery in 16/17 mothers. Sixteen live births were recorded, with two in utero deaths-one secondary to an accident and the second due to antiphospholipid syndrome. Both deaths were considered by investigators to be unrelated to study therapy. All infants were HIV negative at subsequent follow-up and no fetal abnormalities were observed. Pharmacokinetic data suggested that mothers had relatively low exposures to saquinavir despite an excellent virologic response. Saquinavir was not detected in cord blood. DISCUSSION: Saquinavir soft-gel capsules are well tolerated during pregnancy and are not associated in this small study with birth abnormalities. Transmission of HIV infection from mother to child was successfully prevented in all cases. Low maternal exposures of saquinavir were noted. However, these did not appear to affect virologic efficacy of the combination. Samples from cord blood indicate minimal fetal exposure to saquinavir.

Differential responses of mast cell Toll-like receptors 2 and 4 in allergy and innate immunity.

Toll-like receptor 2 (TLR2) and TLR4 play important roles in the early innate immune response to microbial challenge. To clarify the functional roles of TLRs 2 and 4 in mast cells, we examined bone marrow-derived mast cells (BMMCs) from TLR2 or TLR4 gene-targeted mice. Peptidoglycan (PGN) from Staphylococcus aureus stimulated mast cells in a TLR2-dependent manner to produce TNF-alpha, IL-4, IL-5, IL-6, and IL-13, but not IL-1beta. In contrast, LPS from Escherichia coli stimulated mast cells in a TLR4-dependent manner to produce TNF-alpha, IL-1beta, IL-6, and IL-13, but not IL-4 nor IL-5. Furthermore, TLR2- but not TLR4-dependent mast cell stimulation resulted in mast cell degranulation and Ca2+ mobilization. In a mast cell-dependent model of acute sepsis, TLR4 deficiency of BMMCs in mice resulted in significantly higher mortality because of defective neutrophil recruitment and production of proinflammatory cytokines in the peritoneal cavity. Intradermal injection of PGN led to increased vasodilatation and inflammation through TLR2-dependent activation of mast cells in the skin. Taken together, these results suggest that direct activation of mast cells via TLR2 or TLR4 by respective microligands contributes to innate and allergic immune responses.

Cutting edge: VacA, a vacuolating cytotoxin of Helicobacter pylori, directly activates mast cells for migration and production of proinflammatory cytokines.

Mucosal mast cells strategically located at the optimal site interact with invading bacteria. Presence of VacA, the virulent Helicobacter pylori cytotoxin, is correlated with the severity of H. pylori-induced gastritis. To examine the mechanisms of inflammation in H. pylori-induced gastritis, we administered VacA to the mice. Inoculation of VacA resulted in epithelium vacuolization and marked infiltrations of mast cells and mononuclear cells into the mucosal epithelium within 24 h. In an in vitro study using bone marrow-derived mast cells, VacA directly bound and showed a chemotactic activity to the mast cell. In addition, VacA induced bone marrow-derived mast cells to produce proinflammatory cytokines, TNF-alpha, macrophage-inflammatory protein-1alpha, IL-1beta, IL-6, IL-10, and IL-13 in a dose-dependent manner without causing degranulation. The present study suggests that early activation of mast cells by VacA may be the host early response to clear the bacteria and also may contribute to the pathogenesis of H. pylori-induced gastritis.