Abstract
BACKGROUND/AIM: Alkaline extracts of several plants which contain lignin degradation products have several unique biological activities. In order to search for new biological activities of alkaline extracts of pine seed shell (APs), their anti-ultraviolet C (UVC) and macrophage stimulation activity were investigated. MATERIALS AND METHODS: Anti-UVC activity was determined by the ratio of the 50% cytotoxic concentration against human melanoma cell line COLO679 to the 50% UVC-protective concentration. Extracellularly secreted nitrite (NO(2) (-)) by unstimulated and lipopolysaccharide (LPS)-stimulated mouse macrophage-like cells RAW264.7 was determined by Griess method. RESULTS: APs showed significantly higher anti-UVC activity than previously reported hot-water extracts of medical herbs. Anti-UVC activity of AP and vanillic acid was maintained for much longer than that of sodium ascorbate and vanillin. APs enhanced the production of NO(2) (-) to the level induced by LPS. Simultaneous addition of AP and LPS did not further increase NO(2) (-) production, suggesting their mechanisms of action overlap. CONCLUSION: The present study suggests the possible application of APs as UVC protectors and immunopotentiators via macrophage activation.