CHEMICAL COMPOSITION, ANTIMICROBIAL AND ANTIPROLIFERATIVE ACTIVITIES OF THE ESSENTIAL OIL FROM CAMEROONIAN ERIGERON FLORIBUNDUS

Erigeron floribundus (Asteraceae) is a herbaceous plant, 1.5 m in height, with pubescent, lanceolate leaves and flowers in yellowish panicles. In Cameroon it is widely used in the folk medicine to treat angina, female infertility, AIDS, dental pain, headache and various diseases of microbial and non-microbial origin (1). Despite the interest in its bioactivity, the plant has received little phytochemical investigation. For this reason, we became interested in the evaluation of in vitro antimicrobial and antiproliferative activities of the essential oil obtained from the aerial parts of E. floribundus, using agar disc diffusion and microdilution, and MTT methods, respectively. Since essential oils represent an interesting alternative approach against the occurrence of drug resistance in many infectious bacterial pathogens, we completed the work by investigating the inhibitory effects of E. floribundus essential oil on nicotinate mononucleotide adenylyltransferase (NadD). NadD occupies a central position in bacterial NAD+ biosynthesis and is essential for cellular NAD+ synthesis, as demonstrated by gene deletion, targeted protein degradation, and knocking down experiments (2). Based on this finding, NadD has been recently recognized as a promising new target for developing novel antibiotics (3). Another attractive aspect of targeting NadD is that it is highly conserved in the overwhelming majority of bacterial genomes including most pathogens. Therefore, natural products based on NadD inhibition have the potential of possessing wide-spectrum antibacterial activity. The results of this study will be discussed. (1) Berto, C.; Maggi, F.; Nya, P.C.B.; Pettena, A.; Boschiero, I.; Dall'Acqua, S. Phenolic constituents of Erigeron floribundus (Asteraceae), a Cameroonian medicinal plant. Nat. Prod. Commun. 2014, 9, 1691-1694. (2) Sorci, L.; Kurnasov, O.; Rodionov, D.A.; Osterman, A.L. Genomics and Enzymology of NAD Biosynthesis. Comprehensive Natural Products II Chemistry and Biology, Elsevier: Oxford, 2010, 7, 213-257. (3) Petrelli, R.; Felczak, K.; Cappellacci, L. NMN/NaMN adenylyltransferase (NMNAT) and NAD kinase (NADK) inhibitors: chemistry an,d potential therapeutic applications. Curr. Med. Chem. 2011, 18, 1973-1992.