Anti-borreliae efficacy of selected organic oils and fatty acids.

Borrelia sp. is a causative pathogen of Lyme disease which has become a worldwide health concern. Non-toxic approaches especially directed toward latent persistent forms of this pathogen are desired. Lipids in the form of volatile and non-volatile oils, and fatty acids with proven anti-borreliae efficacy could become an additional support or an alternative for consideration in treatment approaches.In this study we investigated 47 lipids (30 volatile and non-volatile oils, and 17 fatty acids) of plant and animal origin against typical motile, knob/round-shaped persisters, and biofilm-like aggregates of Borrelia burgdorferi s.s. and Borrelia garinii, which are identified as pathogenic factors of Lyme disease in the USA and Europe, using direct microscopic counting and spectrofluorometric measurements.Out of all examined lipids, 5 oils (Bay leaf oil, Birch oil, Cassia oil, Chamomile oil German, and Thyme oil) at or below 0.25%, and 3 fatty acids (13Z,16Z Docosadienoic acid, erucic acid, and petroselinic acid) at or below 0.75 mg/ml, showed bactericidal activity against typical motile spirochetes and knob/round-shaped persisters. Only Bay leaf oil and Cassia oil, including their major constituents, eugenol and cinnamaldehyde, showed to target biofilm-like aggregates of both tested Borrelia spp. at the same concentration, although with 20-30% eradication mark.Based on obtained results, volatile oils were more potent than non-volatile oils, and unsaturated fatty acids were more effective than saturated fatty acids. Among all tested oils, Bay leaf oil and Cassia oil, with their major components eugenol and cinnamaldehyde, seem to have the highest anti-borreliae efficacy.