BACKGROUND: Plant extracts have been widely used as important therapeutic drugs for many centuries all over the world. There have been many reports that natural products have various kinds of biological activities such as anti-allergy, anti-inflammatory and antimicrobial activities. Recently, the screening for the efficacy and safety of natural products has been extensively performed. OBJECTIVE: This study was carried out to find a beneficial plant extract possessing excellent antioxidative and anti-melanogenic activities. We have found that the leaf of Robinia pseudo-acacia L. has active substances which are involved in those activities. METHODS: To confirm the antioxidative activity of the extract obtained from the leaves of Robinia pseudo-acacia L., scavenging ability of the extract on DPPH free radicals and its inhibitory effects on lipid autoxidation and peroxidation were investigated. In addition, inhibitory effects of the extract on mushroom tyrosinase as well as melanin biosynthesis in cultured B16 melanoma cells were evaluated. RESULTS: The acacia extract showed not only powerful antioxidative activity but also antimelanogenic acitivity as strong as that of arbutin which is a well known inhibitor of melanogenesis. CONCLUSION: These resulis suggest that the extract from the leaves of Robinia pseudo-acacia L. could be used as a 4ghtening and antioxidative agent for the skin.
Acacia ; Agaricales ; Arbutin ; Biological Products ; Free Radicals ; Mass Screening ; Melanins ; Melanoma, Experimental ; Monophenol Monooxygenase ; Plant Extracts ; Plants ; Robinia* ; Skin

BACKGROUND AND OBJECTIVES: Honey has various biological and pharmacological activities and has been used as treatment against various inflammatory diseases. The aim of this study was to compare the anti-inflammatory characteristics of manuka, kanuka, and black locust honey. MATERIALS AND METHOD: Peripheral blood mononuclear cells (PBMCs) from healthy human volunteers were isolated and then stimulated with lipopolysaccharide (LPS) with or without pre-treatment of various concentrations of honey for 72 hours. The cytotoxic effects of honeys were measured using an aqueous cell proliferation kit, and the supernatants were analyzed for interleukin-5 (IL-5), IL-10, interferon-γ (INF-γ), and tumor necrosis factor-α (TNF-α) using an enzyme-linked immunosorbent assay. RESULTS: Samples of 1% manuka and kanuka honey were found to have cytotoxic effects on PBMCs. Honey itself enhanced the production of IL-10 and TNF-α production. Manuka and kanuka honeys suppressed LPS-induced IL-10 and INF-γ production, while black locust honey only suppressed IL-10 production from PBMCs. CONCLUSION: Honeys had immunomodulatory properties of both immunostimulatory and immunosuppressive effects on PBMCs. Different honeys might have different immune modulatory functions due to their different components.
Cell Proliferation ; Enzyme-Linked Immunosorbent Assay ; Healthy Volunteers ; Honey* ; Interleukin-10 ; Interleukin-5 ; Kunzea* ; Methods ; Necrosis ; Robinia*