Extraction and Fractionation of Bioactives from Dipsacus fullonum L. Leaves and Evaluation of Their Anti- Borrelia Activity

Lyme disease (LD) is a tick-borne bacterial disease that is caused by . Although acute LD is treated with antibiotics, it can develop into relapsing chronic form caused by latent forms of . This leads to the search for phytochemicals against resistant LD. Therefore, this study aimed to evaluate the activity of L. leaves extract (DE) and its fractions against stationary phase in vitro. DE showed high activity against stationary phase (residual viability 19.8 ± 4.7%); however, it exhibited a noticeable cytotoxicity on NIH cells (viability 20.2 ± 5.2%). The iridoid-glycoside fraction showed a remarkable anti- effect and reduced cytotoxicity. The iridoid-glycoside fraction was, therefore, further purified and showed to contain two main bioactives-sylvestrosides III and IV, that showed a considerable anti- activity being the least toxic to murine fibroblast NIH/3T3 cells. Moreover, the concentration of sylvestrosides was about 15% of DE, endorsing the feasibility of purification of the compounds from L. leaves.