Anti-inflammatory, pro-proliferative and antimicrobial potential of the compounds isolated from Daemonorops draco (Willd.) Blume

Ethno-pharmacological relevance: Daemonorops draco (D. draco) commonly known as "Dragon's blood" is one of the most used plants by Momok, Anak Dalam and Talang Mamak tribes from Indonesia as a remedy for wound healing. Aim of the study: This study aimed to identify the extract, fractions and compounds responsible for the anti-inflammatory and pro-proliferative activities of the D. draco resin. Additionally, the antimicrobial activity against two bacteria and one yeast species was analysed. Materials and methods: Bio-guided isolation of compounds with anti-inflammatory, pro-proliferative and antimicrobial activities from the D. draco resin was carried out by measuring: the inhibition of NF-kappa B and activation of Nrf2 in THP-1, HaCaT, NIH-3T3 cells; cell proliferation in NIH-3T3 and HaCaT cells; and the antimicrobial effect on E. coli, S. aureus and C. albicans. Results: Guided isolation by bioassay gave rise to the isolation and characterisation by nuclear magnetic resonance and mass spectrometry of three compounds: 1 (Bexarotene), 2 (Taspine) and 3 (2-hydroxy-1-naphthaldehyde isonicotinoyl hydrazone). All compounds showed NF-kappa B inhibitory activity with IC50 values of 0.10-0.13, 0.22-0.24 and 3.75-4.78 mu M, respectively, while the positive control, Celastrol, had an IC50 of 7.96 mu M. Likewise, all compounds showed an activating effect of Nrf2 with EC50 values of 5.34-5.43, 163.20-169.20 and 300.82-315.56 nM, respectively, while the positive control, CDDO-Me, had an EC50 of 0.11 nM. In addition, concerning the pro-proliferative activity, compound 1 (IC50 = 8.62-8.71 nM) showed a capacity of 100%, compound 2 (IC50 = 166-171 nM) showed a capacity of 75%, and compound 3 (IC50 = 469-486 nM) showed a capacity of 65%, while FSB 10% (positive control) had a pro-proliferative activity of 100% in the NIH3T3 cell lines (fibroblasts) and HaCaT (keratinocytes). Finally, all the compounds showed antimicrobial activity with MIC values of 0.12-0.16, 0.31-0.39 and 3.96-3.99 mu M, respectively, in S. aureus, E. coli and C. albicans strains, while the positive control, Ofloxacin, had a MIC of 27.65 mu M. Conclusion: This study managed to isolate, for the first time, three compounds (Bexarotene, Taspine and 2-hydroxy-1-naphthaldehyde isonicotinoyl hydrazone) from the resin of D. draco, with anti-inflammatory, and pro proliferative as well as antimicrobial activities.