Antibacterial activities of natural lichen compounds against Streptococcus gordonii and Porphyromonas gingivalis

Alaa Sweidan (1, 2) , Marylene Chollet-Krugler (3) , Aurélie Sauvager (3) , Pierre van de Weghe (4) , Ali Chokr (1) , Martine Bonnaure-Mallet (5, 2) , Sophie Tomasi (3) , Latifa Bousarghin (2)

1 LU / ULB - الجامعة اللبنانية [بيروت] = Lebanese University [Beirut] = Université libanaise [Beyrouth]
2 NuMeCan - Nutrition, Métabolismes et Cancer
3 ISCR - Institut des Sciences Chimiques de Rennes
4 COSS - Chemistry, Oncogenesis, Stress and Signaling
5 Centre Hospitalier Universitaire de Rennes [CHU Rennes] = Rennes University Hospital [Ponchaillou]

The oral bacteria not only infect the mouth and reside there, but also travel through the blood and reach distant body organs. If left untreated, the dental biofilm that can cause destructive inflammation in the oral cavity may result in serious medical complications. In dental biofilm, Streptococcus gordonii, a primary oral colonizer, constitutes the platform on which late pathogenic colonizers like Porphyromonas gingivalis, the causative agent of periodontal diseases, will bind. The aim of this study was to determine the antibacterial activity of eleven natural lichen compounds belonging to different chemical families and spanning from linear into cyclic and aromatic structures to uncover new antibiotics which can fight against the oral bacteria. The compounds were screened by broth microdilution assay. Three compounds were shown to have promising antibacterial activities where the depsidone core with certain functional groups constituted the best compound, psoromic acid, with the lowest MICs=11.72 and 5.86μg/mL against S. gordonii and P. gingivalis, respectively. The compounds screened had promising antibacterial activity which might be attributed to some important functional groups as discussed in our study. The best compounds did not induce the death of gingival epithelial carcinoma cells (Ca9-22). These results introduce new compounds having potent antibacterial activities against oral pathogens causing serious medical complications.

Mots clés: (+)-Roccellic acid (R) (PubChem CID: 11449446); (+)-Erythrin (E) (PubChem CID: 12308905); (+)-acetylportentol (A) (PubChem CID: 101282317); Variolaric acid (Var) (PubChem CID: 12444681); Screening; Streptococcus gordonii; antibacterial activity; Conhypoprotocetraric acid (C) (PubChem CID: 101282317); Demethylbarbatic acid (D) (PubChem CID: 10450302); Hypoprotocetraric acid (H) (PubChem CID: 627044); Lepraric acid (L) (PubChem CID: 12304992); Lichen; Methyl-beta-orcinolcarboxylate (M) (PubChem CID: 78435); Porphyromonas gingivalis; Psoromic acid (P) (PubChem CID: 23725); Vulpinic acid (Vul) (PubChem CID: 54690323)

Domaines: Chimie

Alaa Sweidan, Marylene Chollet-Krugler, Aurélie Sauvager, Pierre van de Weghe, Ali Chokr, et al.. Antibacterial activities of natural lichen compounds against Streptococcus gordonii and Porphyromonas gingivalis. Fitoterapia, 2017, 121, pp.164-169. ⟨10.1016/j.fitote.2017.07.011⟩. ⟨hal-01579650⟩