Volatile compounds from Padina pavonica and Dictyopteris polypodioides display in-vitro antitumoral activity possibly reflecting carbonic anhydrase inhibition

Padina pavonica and Dictyopteris polypodioides are two widely distributed brown seaweeds whose pharmacological applications remain underestimated. In the present study, ethanolic extracts of P. pavonica and D. polypodioides were tested for cytotoxic activity against MCF-7 (human breast adenocarcinoma), Caco-2 (human colon adenocarcinoma), and HepG2 (human hepatoma) cells. Both seaweeds displayed significant cytotoxic activity against tumoral cells, with D. polypodioides being more effective than P. pavonica. Composition of volatile metabolites in P. pavonica and D. polypodioides was characterized by headspace gas chromatography-mass spectrometry (GC-MS). A total of 35 different volatile metabolites were identified in the two seaweed species. Considering that numerous human pathologies including cancer involve the participation of carbonic anhydrase activity, these compounds were screened as potential inhibitors of human carbonic anhydrase using molecular docking simulation. The results showed that p-acetaminobenzaldehyde and methyl 9(Z)-octadecenoate from P. pavonica, and 6-hydroxynicotinic acid, methyl 7-nonynoate, and methyl (7E)-hexadecenoate from D. polypodioides have high fitness scores, and they, therefore, are promising candidates for prospective pharmacological research.