Polysaccharide extracts of the brown alga Sargassumasperifolium possess in vitro cancer chemopreventive properties

Abstract

The cancer chemopreventive activity of the polysaccharide extracts (E1–E4) of Sargassum asperifolium, a brown alga in Red Sea shores in Egypt, was investigated. Tumour anti-initiation activity (the modulation of carcinogen metabolism) indicated that E3 and E4 were potent anti-initiators by inhibiting the carcinogen activator cytochrome P450-1A, and enhancing carcinogen detoxification enzymes glutathione-S-transferase. Only E4 significantly enhanced quinone reductase activity. All polysaccharide extracts possessed anti-promotion property by their anti-inflammatory activity. E3 and E4 dramatically induced the growth of spleen macrophages. E2, E3 and E4 significantly inhibited nitric oxide generation from lipopolysaccharide (LPS)-stimulated spleen macrophages, while E1, E3 and E4 led to significant inhibition of LPS-induced tumour necrosis factor-α. The extracts E1, E2 and E4 showed cytotoxicity against HepG2 cells, where E2 and E4 induced cell death due to apoptosis. In conclusion, E3 and E4 are promising cancer chemopreventive extracts, since they had tumour anti-initiating activity via their protective modulation of carcinogen metabolism.

Keywords::

• Sargassumasperifolium
• cytochrome P450 1A
• cancer chemoprevention
• anti-initiating
• anti-promoting
• apoptosis

Acknowledgement

This work was supported by the National Research Center, Cairo, Egypt.

Conflict of interest statement

The authors declare that there is no conflict of interest.