In this study, Ledum palustre L. was extracted by 4 different methods (LPW, hot water extraction; LPA, autoclave extraction; LPU, ultrasonification extraction; LPE, 70% ethanol extraction) and LPE was fractionated by using polarity difference of each solvent and used as 4 samples (LPE/H, the n-hexane layer; LPE/E, the EtOAc layer; LPE/B, the n-BuOH layer; LPE/W, the H2O layer). Antioxidant activities of Ledum palustre L. extracts were measured by DPPH and ABTS. As a result, the DPPH and ABTS radical scavenging showed high activities with LPE (82.3%, 99.8%) and LPE/E (91.8%, 99.6%) at the concentration of 1,000 μg/mL. The anti-inflammatory activities of LPE and LPE/E were measured by the inhibitory activity against NO, PGE2, TNF-α, IL-1β and IL-6 production on LPS-stimulated Raw 264.7 macrophages. As a result of MTT assay, cell viabilities of LPE and LPE/E were more than 90% at 25 μg/mL. NO and PGE2 productions were inhibited by LPE (NO: 50%, PGE2: 70%) and LPE/E (NO: 57%, PGE2: 73%) at the concentration of 25 μg/mL. The inhibition activities against TNF-α, IL-1β, IL-6 production were 24%, 47% and 40% at the concentration of 25 μg/mL of LPE. In particular, LPE/E showed 51%, 57% and 62% inhibition activities at the same concentration, respectively. From the above results, it can be concluded that 1,000 μg/mL of LPE and LPE/E have the high antioxidant activities similar with Vitamin C, and 25 μg/mL, the low concetration of LPE and LPE/E have excellent anti-inflammatory activities. Therefore, if more research about anti-aging, whitening and antimicrobial activity of Ledum palustre L. extracts is carried out in the future, it will be possible to use them as effective materials for the prevention and treatment of inflammatory diseases and in the areas of functional foods and cosmetics.
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