Akt (protein kinase B) is a serine/threonine protein kinase that regulates cell metabolism, survival and proliferation. Recent studies of the role of Akt in phagocytosis, intracellular bacterial infections, LPS tolerance, production of inflammatory cytokines and mediators, and migration during macrophage-mediated innate immunity strongly suggest a pivotal role for this enzyme in the functional activation of macrophages. Considering that a variety of inflammatory diseases, such as rheumatoid arthritis, atherosclerosis, diabetes, obesity, cancer and osteoporosis, are regulated by macrophage-mediated innate immunity, efforts should be more carefully focused on understanding the function of Akt in macrophage-mediated innate immunity. Although few studies have addressed this question, this review discusses recent findings that support an important role for Akt in macrophage-mediated innate immunity and underlines the need for trials to develop pharmaceutically useful drugs that target Akt for treatment of macrophage-mediated inflammatory diseases. The findings we review here suggest that a novel and safe Akt inhibitor with strong immunosuppressive and anti-inflammatory properties will be applied to various chronic inflammatory diseases in the near future.

The objective of this study was to examine the biological activity of kaempferol and its rhamnosides. We isolated kaempferol (1), α-rhamnoisorobin (2), afzelin (3), and kaempferitrin (4) as pure compounds by far-infrared (FIR) irradiation of kenaf (Hibiscus cannabinus L.) leaves. The depigmenting and anti-inflammatory activity of the compounds was evaluated by analyzing their structure-activity relationships. The order of the inhibitory activity with regard to depigmentation and nitric oxide (NO) production was kaempferol (1) > α-rhamnoisorobin (2) > afzelin (3) > kaempferitrin (4). However, α-rhamnoisorobin (2) was more potent than kaempferol (1) in NF-κB-mediated luciferase assays. From these results, we conclude that the 3-hydroxyl group of kaempferol is an important pharmacophore and that additional rhamnose moieties affect the biological activity negatively.

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Ginsenoside (G)-F1 is an enzymatic metabolite generated from G-Rg1. Although this metabolite has been reported to suppress platelet aggregation and to reduce gap junction-mediated intercellular communication, the modulatory activity of G-F1 on the functional role of skin-derived cells has not yet been elucidated. In this study, we evaluated the regulatory role of G-F1 on the cellular responses of B16 melanoma cells. G-F1 strongly suppressed the proliferation of B16 cells up to 60% at 200 µg/mL, while only diminishing the viability of HEK293 cells up to 30%. Furthermore, G-F1 remarkably induced morphological change and clustering of B16 melanoma cells. The melanin production of B16 cells was also significantly blocked by G-F1 up to 70%. Interestingly, intracellular signaling events involved in cell proliferation, migration, and morphological change were up-regulated at 1 h incubation but down-regulated at 12 h. Therefore, our results suggest that G-F1 can be applied as a novel anti-skin cancer drug with anti-proliferative and anti-migration features.

Saponins are valuable principles found in various herbal medicine with pharmaceutical, cosmetical and nutraceutical merits. In this study, we evaluated the protective role of saponin fraction (Cl-SF), prepared from Codonopsis lanceolata, an ethnopharmacologically famous plant in Korea, China and Japan, on water immersion stress-induced liver damage and radical generation. Cl-SF clearly decreased the up-regulated levels of serum glutamate-oxalacetate transaminase and glutamate-pyruvate-transaminase induced by water-immersed stress conditions. Furthermore, Cl-SF seemed to block the stress-induced radicals. Thus, Griess and DPPH assays revealed that Cl-SF significantly suppressed both radical generation in sodium nitroprusside-treated RAW264.7 cells and nitric oxide production in LPS-treated RAW264.7 cells. Therefore, these results suggest that Cl-SF may be considered as a promising stress-regulatory principle with radical scavenging actions.