Ursolic, oleanolic and betulinic acids: antibacterial spectra and selectivity indexes.
BACKGROUND
Ursolic acid (UA), oleanolic acid (OA) and betulinic acid (BA), three hydroxyl pentacyclic triterpenoic acids (HPTAs) naturally found in a large variety of vegetarian foods, medicinal herbs and plants have been investigated for antibacterial activity.


OBJECTIVE
To determine the antibacterial activity of UA, OA and BA, as well as the toxic impact on eukaryotic cells.


METHODS
Minimum inhibitory concentrations were determined against five reference strains (Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923 & ATCC 29213, Enterococcus faecalis ATCC 29212 and Pseudomonas aeruginosa ATCC 27853), as well as five antibiotic-resistant clinical isolates. Toxicity was evaluated against MRC-5 and HaCaT cell lines.


RESULTS
No antibacterial activity was observed for BA; while OA and more particularly UA, did show a moderate to good antibacterial activity, but limited to Gram-positive bacteria. Nevertheless, OA and UA were devoid of antibacterial activities against clinical isolates. Moreover, viability and cytotoxic assays demonstrated that the three compounds induced a significant cytotoxicity.


CONCLUSIONS
Despite of a relative similar chemical structure; UA, OA and BA harboured different antibacterial activities, with more significant ones for UA. However, considering both viability and toxicity values, these compounds seem to have a significant impact on eukaryotic cell viability.
Fontanay
Stéphane
S
SRSMC, Nancy-University, CNRS, France.
Grare
Marion
M
Mayer
Joséphine
J
Finance
Chantal
C
Duval
Raphaël Emmanuel
RE
D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000633:toxicity; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D024881:Drug Resistance, Bacterial; D005057:Eukaryotic Cells / Q000187:drug effects / Q000378:metabolism; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D006801:Humans; D008826:Microbial Sensitivity Tests; D009828:Oleanolic Acid / Q000494:pharmacology* / Q000633:toxicity; D053978:Pentacyclic Triterpenes; D018675:Toxicity Tests; D014315:Triterpenes / Q000494:pharmacology* / Q000633:toxicity; D000094062:Betulinic Acid; D000097245:Ursolic Acid
D000900:Anti-Bacterial Agents; D009828:Oleanolic Acid; D053978:Pentacyclic Triterpenes; D014315:Triterpenes; D000094062:Betulinic Acid; D000097245:Ursolic Acid