Potential Secondary Metabolites from Marine Sponge Aaptos aaptos for Atherosclerosis and Vibriosis Treatments

Abstract

Natural products play a crucial role in drug discovery. In the last decade, the advent of marine natural product research has produced a remarkable number of compounds, particularly those isolated from marine sponges, with a broad range of activities for the treatment of human and animal diseases. In this study, five known alkaloids namely aaptamine (1), 9-demethylaaptamine (2), 4- N-methylaaptamine (3), 9-methoxyaaptamine (4), 9-demethyloxyaaptamine (5), an uncommon amide in sponge, 4-hydroxybenzamide (6) and 3 β,5α-cholesterol (7) were isolated from the butanol extract of Aaptos aaptos (Schmidt, 1864) by bioactivity-guided isolation. Their structures were determined based on a detailed analysis of their 1D and 2D spectroscopic NMR and EIMS spectral data as well as comparison with literature data. Cytotoxic activity and anti-atherosclerotic property of the compounds were determined based on their ability to increase the transcriptional activity of SRB1 promoter and PPRE in human liver HepG2 cell line. The results showed that compounds 4 and 7 exhibited cytotoxic effects and compounds 1–4 and 7 increased the transcriptional activity of SRB1 promoter and PPRE. This suggests that compounds isolated from A. aaptos may have potential as anti-cancer agents and to reduce the progression of atherosclerosis. In addition, the compounds 1–4 displayed antibacterial activity against shrimp pathogenic bacteria, Vibrio harveyi and Vibrio sp. This suggests that the compounds have potential as vibriosis treatment.