| Summary: | 碩士 === 元培醫事科技大學 === 生物技術研究所 === 103 === Juniperonic acid (JPA; Δ5,11,14,17-20:4), a non-methylene-interrupted fatty acids (NMIFA), is a rare ω-3 polyunsaturated fatty acids (ω-3 PUFA) originally found in gymnosperms. Previous studies demonstrated that most ω-3 PUFA or NMIFA exert anti-inflammatory activities, therefore, the objective of this study was to investigate whether JPA inhibits the production of inflammatory mediators, since JPA is also a member of NMIFA and n-3 PUFA. Using combined techniques of lipid biochemistry and column chromatography, we extracted and purified JPA from seeds of Biota orientalis. Next, we incubated murine RAW264.7 macrophages to determine how JPA could be metabolized and modulate lipopolysaccharide (LPS)-stimulated production of numerous biomarkers. Results showed that JPA was enriched and separated by urea inclusion and argentated column chromatography, respectively, and its purity is greater than 98% as analyzing by gas chromatography (GC) and GC-mass spectrometry (GC-MS). There was no negative effect on cell proliferation when cells were incubated with JPA (200 μM or less), and incorporated JPA in cellular phospholipids could be metabolized to Δ7-docosatetraenoic acid (Δ7-DTA). The proportion of cellular JPA changed differentially with time, however, that of Δ7-DTA increased in a time-dependent manner. When incubated cells with different concentrations of JPA, amounts of cellular phospholipid JPA and Δ7-DTA increased dose-dependently. Increasing incorporation of JPA into cellular phospholipids also decreased the proportion of total monounsaturated fatty acid (MUFA). This incorporation did not affect the percentage of total saturated fatty acid (SFA), but increased that of total PUFA. Furthermore, JPA incorporation results in the decrease in the proportion of arachidonic acid (AA). JPA suppressed the production of nitric oxide (NO), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), however no such effect on that of prostaglandin E2 (PGE2) was observed. The reduction of NO might be resulted from the suppression of inducible nitric oxide synthase (iNOS) expression. However, the suppression of COX-2 over-expression by JPA might not account for the increasing levels of PGE2. Results of this study would provide a better understanding of the function mechanisms and modulatory effect of JPA on inflammation, and useful information for the future application.
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