Bum Chun Lee

Biological activities of the polysaccharides produced from submerged culture of the edible Basidiomycete Grifola frondosa

Five groups of polysaccharides were prepared from mycelium extract and top and bottom fraction of filtrate precipitates by submerged culture of Grifola frondosa at two different media (glucose and PMP medium) and their individual biological activities were studied. These polysaccharides had diverse molecular mass (470–1650 kDa) and different biological activities at the concentrations of 0.01–0.2% (w/v). Most of polysaccharides had antioxidant and free radical scavenging activities after UV irradiation, where G-2 (bottom fraction of filtrate precipitates from glucose medium, MW 770 kDa) and G-3 polysaccharide (mycelium extract from glucose medium, MW 500 kDa) showed strong activity. The P-1 (from top fraction of filtrate precipitates from PMP medium, MW 1650 kDa) and P-3 polysaccharide (from mycelium extract from PMP medium, MW 470 kDa) increased the proliferation of fibroblasts by approximately 23–25%. Other two groups of polysaccharides produced from glucose medium (G-2 and G-3 polysaccharides) showed also notable proliferation activity for fibroblasts. Treatment of fibroblasts with P-3 polysaccharide significantly increased the biosynthesis of collagen by approximately 80%. G-2 and G-3 polysaccharides showed also marked activity. However, G-1 and P-1 polysaccharides had only negligible activity in collagen biosynthesis.

The isolation and antioxidative effects of vitexin fromAcer palmatum

Free radicals and reactive oxygen species (ROS) caused by UV exposure or other environmental factors are critical players in cellular damage and aging. In order to develop a new antiphotoaging agent, this work focused on the antioxidant effects of the extract of tinged autumnal leaves ofAcer palmatum. One compound was isolated from an ethyl acetate soluble fraction of theA. palmatum extract using silica gel column chromatography. The chemical structure was identified as apigenin-8-C-beta-D-glucopyranoside, more commonly known as vitexin, by spectral analysis including LC-MS, FT-IR, UV,1H-, and13C-NMR. The biological activities of vitexin were investigated for the potential application of its anti-aging effects in the cosmetic field. Vitexin inhibited superoxide radicals by about 70% at a concentration of 100 μg/mL and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals by about 60% at a concentration of 100 μg/mL Intracellular ROS scavenging activity was indicated by increases in dichlorofluorescein (DCF) fluorescence upon exposure to UVB 20 mJ/cm2 in cultured human dermal fibroblasts (HDFs) after the treatment of vitexin. The results show that oxidation of 5-(6-)chloromethyl-2′,7′-dichlorodihydrofluorescein diacetate (CM-H2DCFDA) is inhibited by vitexin effectively and that vitexin has a potent free radical scavenging activity in UVB-irradiated HDFs. In ROS imaging using a confocal microscope we visualized DCF fluorescence in HDFs directly. In conclusion, our findings suggest that vitexin can be effectively used for the prevention of UV-induced adverse skin reactions such as free radical production and skin cell damage.

Antioxidants and inhibitor of matrix metalloproteinase-1 expression from leaves of Zostera marina L.

In order to develop new anti-photoaging agents, we examined the antioxidative activity and the inhibition effect of matrix metalloproteinase-1 (MMP-1) on the extracts of a marine product,Zostera marina L., which is known for its potent activity. Three compounds (compounds1,2, and3) were isolated from an ethyl acetate (EtOAc) soluble fraction of the product; they were identified as apigenin-7-O-β-D-glucoside (1), chrysoeriol (2), and luteolin (3). These compounds were found to scavenge radicals and reactive oxygen species (ROS) and were measured to have SC50 values of 0.18 mM, 0.68 mM, and 0.01 mM against the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and 0.04 mM, 0.03 mM, and 0.01 mM against the superoxide radical in the xanthine/xanthine oxidase system, respectively. Compound 3 suppressed the expression of MMP-1 by up to 44% at 4.0 μM and inhibited the production of interleukin 6 (IL-6), which is known as a cytokine that induces MMP-1 expression. From these results, compound3 and the other compounds were determined to have antioxidative activity and to inhibit MMP-1 expression. Thus, the three compounds are expected to be useful for preventing the photoaging of skin.

Stimulative and sedative effects of essential oils upon inhalation in mice

This study investigated the stimulative or sedative effects of inhaling fragrant essential oils (EOs) by using a forced swimming test (FST) with mice. This behavioral test is commonly used to measure the effects of antidepressant drugs. The inhalation by mice of EOs, such as ginger oil (p<0.05), thyme oil (p<0.05), peppermint oil (p<0.05), and cypress oil (pš0.01) resulted in 5% to 22% reduction of immobility. The same results were achieved when over-agitation was artificially induced in the mice by an intraperitoneal injection of caffeine (a psycho-stimulant). In contrast, inhalation of some EOs by the mice resulted in increased immobility. To evaluate more correctly the sedative effects of EOs, the immobility of over-agitated mice induced with caffeine was ascertained after the inhalation of various EOs. Inhalation of lavender oil (p<0.01) and hyssop oil (p<0.01) increased the immobile state in mice that were treated with caffeine. The results of this study indicate that the inhalation of essential oils may induced stimulative or sedative effects in mice.