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BackgroundPolyphenols in tea are considered beneficial to human health. However, many such claims of their bioactivity still require in vitro and in vivo evidence.ResultsUsing Drosophila melanogaster as a model multicellular organism, we assess the fat accumulation-suppressing effects of theaflavin (TF), a tea polyphenol; epitheaflagallin (ETG), which has an unknown function; and epigallocatechin gallate (EGCg), a prominent component of green tea. Dietary TF reduced the malondialdehyde accumulation related to a high-fat diet in adult flies. Other physiological and genetic responses induced by the high-fat diet, such as lipid accumulation in the fat body and expression of lipid metabolism-related genes, were ameliorated by the addition of TF, ETG, and EGCg, in some cases approaching respective levels without high-fat diet exposure. Continuous ingestion of the three polyphenols resulted in a shortened lifespan.ConclusionWe provide evidence in Drosophila that tea polyphenols have a fat accumulation-suppressing effect that has received recent attention. We also suggest that tea polyphenols can provide different desirable biological activities depending on their composition and the presence or absence of other chemical components.

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Background. Hot water extract of Sasa albomarginata (Kumazasa) leaves is commercially available and used as a dietary supplement or skincare cream. The extract possesses anti-inflammatory activity on the mouse atopic dermatitis model. To elucidate the mechanism of in vivo activity, we have studied the cellular anti-inflammatory and antioxidant activities of the extract and its constituents. Methods. Secretion of mouse and human IL-6 was measured by ELISA. ROS production was measured by a fluorescent reagent. Ultrahigh performance liquid chromatography (UHPLC)/MS was used for the ingredient analysis. Results. The Sasa albomarginata extract inhibited inflammatory mediators such as LPS-induced NO, IL-6, and ROS production in mouse monocyte leukemia RAW264.7 cells. It also inhibited iNOS, IL-6, and IL-1β expressions. Moreover, it inhibited LPS-induced IL-6 expression and production in human monocyte leukemia THP-1 cells differentiated into macrophages. The HPLC analysis of the extract revealed the existence of coumaric acid, ferulic acid, and coumaric acid methyl ester. Coumaric acid methyl ester but not coumaric acid or ferulic acid inhibited LPS-induced NO, IL-6, and ROS production in RAW264.7 cells and IL-6 production in differentiated THP-1 cells. Conclusion. The hot water extract of Sasa albomarginata leaves and one of its constituents possess cellular anti-inflammatory and antioxidant activities.