Novel anti-inflammatory omega-3 PUFAs from the New Zealand green-lipped mussel, Perna canaliculus

The present study has identified in the marine mollusc, Perna canaliculus, an homologous series of novel omega 3 polyunsaturated fatty acids (ω-3 PUFA) with significant anti-inflammatory (AI) activity. The free fatty acid (FFA) class was isolated from a supercritical-CO₂ lipid extract of the tartaric acid-stabilised freeze-dried mussel powder by normal phase chromatography, followed by reversed-phase high performance liquid chromatography (RP–HPLC). The RP–HPLC involved separation based on carbon numbers, followed by argentation–HPLC (Ag–HPLC) of the methyl esters based on degree of unsaturation. Identification of the FFA components was performed using gas chromatography (GC) with flame ionisation detection, and individual structures were assigned by GC-mass spectroscopy (GC-MS). Inhibition of leukotriene production by stimulated human neutrophils was used as an in vitro screening method to test the AI activity of the purified PUFAs. A structurally related family of ω-3 PUFAs was identified in the most bioactive fractions, which included C18:4, C19:4, C20:4, and C21:5 PUFA. The C20:4 was the predominant PUFA in the extract, and was a structural isomer of arachidonic acid (AA). The novel compounds may be biologically significant as AI agents, as a result of their in vitro inhibition of lipoxygenase products of the AA pathway.