ABSTRACT
Five asterosaponins (1-5), including one new compound named protonodososide (1), were isolated from the methanol extract of the starfish Protoreaster nodosus, after subjecting to various chromatographic separations. The structural elucidation was confirmed by careful analysis of the 1D, 2D NMR, and HR ESI QTOF mass spectra. The cytotoxicity of isolated compounds was evaluated on five human cancer cell lines including HepG2, KB, MCF7, LNCaP, and SK-Mel2.
Subject(s)
Antineoplastic Agents , Starfish , Animals , Humans , Starfish/chemistry , Magnetic Resonance Spectroscopy , Cell Line, Tumor , Spectrometry, Mass, Electrospray Ionization , Antineoplastic Agents/chemistry , Molecular StructureABSTRACT
The Coral Triangle is widely considered the most important centre of marine biodiversity in Asia while areas on its periphery such as the South China Sea, have received much less interest. Here, we demonstrate that a small population of the knobbly sea star Protoreaster nodosus in Singapore has similarly high levels of genetic diversity as comparable Indonesian populations from the Coral Triangle. The high genetic diversity of this population is remarkable because it is maintained despite decades of continued anthropogenic disturbance. We postulate that it is probably due to broadcast spawning which is likely to maintain high levels of population connectivity. To test this, we analysed 6140 genome-wide single nucleotide polymorphism (SNP) loci for Singapore's populations and demonstrate a pattern of near panmixia. We here document a second case of high genetic diversity and low genetic structure for a broadcast spawner in Singapore, which suggests that such species have high resilience against anthropogenic disturbances. The study demonstrates the feasibility and power of using genome-wide SNPs for connectivity studies of marine invertebrates without a sequenced genome.
ABSTRACT
BACKGROUND: In the present study, we examined the inhibitory effects of a methanolic extract, dichloromethane fraction, water layer, and polyhydroxylated sterols (1-4) isolated from the Vietnamese starfish Protoreaster nodosus on pro-inflammatory cytokine (IL-12 p40, IL-6, and TNF-α) production in LPS-stimulated bone marrow-derived dendritic cells (BMDCs) using enzyme-linked immunosorbent assays (ELISA). RESULTS: The methanolic extract and dichloromethane fraction exerted potent inhibitory effects on the production of all three pro-inflammatory cytokines, with IC50 values ranging from 0.60 ± 0.01 to 26.19 ± 0.64 µg/mL. Four highly pure steroid derivatives (1-4) were isolated from the dichloromethane fraction and water layer of P. nodosus. Potent inhibitory activities were also observed for (25S)5α-cholestane-3ß,4ß,6α,7α,8ß,15α,16ß,26-octol (3) on the production of IL-12 p40 and IL-6 (IC50s = 3.11 ± 0.08 and 1.35 ± 0.03 µM), and for (25S) 5α-cholestane-3ß,6α,8ß,15α,16ß,26-hexol (1) and (25S)5α-cholestane-3ß,6α,7α,8ß,15α,16ß,26-heptol (2) on the production of IL-12 p40 (IC50s = 0.01 ± 0.00 and and 1.02 ± 0.01 µM). Moreover, nodososide (4) exhibited moderate inhibitory effects on IL-12 p40 and IL-6 production. CONCLUSION: This is the first report of the anti-inflammatory activity from the starfish P. nodosus. The main finding of this study is the identification oxygenated steroid derivatives from P. nodosus with potent anti-inflammatory activities that may be developed as therapeutic agents for inflammatory diseases.
