Marine sponge Hymeniacidon sp. amphilectane metabolites potently inhibit rat brain microglia thromboxane B2 generation

The effects of five Hymeniacidon sp. amphilectane metabolites (1-5) and two semi-synthetic analogs (6 and 7) on thromboxane B(2) (TXB(2)) and superoxide anion (O(2)(-)) generation from Escherichia coli LPS-activated rat brain microglia were investigated. All Hymeniacidon sp. metabolites and analogs potently inhibited TXB(2) (IC(50)=0.20-4.69μM) with low Lactate Dehydrogenase release and minimal mitochondrial dehydrogenase inhibition. While a lack of O(2)(-) inhibition would suggest that Hymeniacidon sp. metabolites and derivatives inhibit TXB(2) synthesis by a cyclooxygenase-dependent mechanism, their pharmacologic potency and limited in vitro cytotoxicity warrants further investigation to develop them as lead compounds to modulate enhanced TBX(2) release by activated microglia in neuroinflammatory disorders.