Effectiveness of Stevia rebaudiana whole leaf extract against the various morphological forms of Borrelia burgdorferi in vitro

Abstract

Lyme disease is a tick-borne multisystemic disease caused by Borrelia burgdorferi. Administering antibiotics is the primary treatment for this disease; however, relapse often occurs when antibiotic treatment is discontinued. The reason for relapse remains unknown, but recent studies suggested the possibilities of the presence of antibiotic resistant Borrelia persister cells and biofilms.In this study, we evaluated the effectiveness of whole leaf Stevia extract against B. burgdorferi spirochetes, persisters, and biofilm forms in vitro. The susceptibility of the different forms was evaluated by various quantitative techniques in addition to different microscopy methods. The effectiveness of Stevia was compared to doxycycline, cefoperazone, daptomycin, and their combinations. Our results demonstrated that Stevia had significant effect in eliminating B. burgdorferi spirochetes and persisters. Subculture experiments with Stevia and antibiotics treated cells were established for 7 and 14 days yielding, no and 10% viable cells, respectively compared to the above-mentioned antibiotics and antibiotic combination. When Stevia and the three antibiotics were tested against attached biofilms, Stevia significantly reduced B. burgdorferi forms. Results from this study suggest that a natural product such as Stevia leaf extract could be considered as an effective agent against B. burgdorferi.

Effect of RpoN, RpoS and LuxS pathways on the biofilm formation and antibiotIc sensitivity of Borrelia burgdorferi

“…We also suggested that Borrelia biofilm formation could result in increased resistance to various antibiotics [3, 35]. Numerous studies showed that one of the most effective hiding places for a bacterial species is biofilm [36, 37].…”

Reciprocal cooperation of phytochemicals and micronutrients against typical and atypical forms ofBorreliasp.

“…; Theophilus et al . ). Briefly, 1·8 ml sterile screw‐cap test tubes containing 1‐ml BSK‐H complete medium, supplemented with the tested combination of agents, were inoculated with 2 × 10 6 spirochaetes per millilitre of the homogenous bacterial suspension (3‐day culture in logarithmic phase) or 1 × 10 7 spirochaetes per millilitre of the homogenous bacterial suspension (8‐day culture in stationary phase).…”

“…; Theophilus et al . ). Briefly, 1 × 10 6 (in logarithmic phase) and 1 × 10 7 spirochaetes per millilitre of the homogenous bacterial suspension (in stationary phase), respectively, were inoculated into each 1·8 ml sterile screw‐cap test tube containing 1 ml BSK‐H complete medium supplemented with the tested combination of agents.…”

“…; Theophilus et al . ). However, these studies together with others that examined synthetic biocides and antibiotics showed that it is still a challenge for them to be effective, when applied individually, to either become therapeutics or be effective against all pleomorphic forms of Borrelia sp.…”

Cooperation of Doxycycline with Phytochemicals and Micronutrients Against Active and Persistent Forms of Borrelia sp

“…Despite a rather small pool of available data on this subject, Bronson and Bronson study exhibited grapefruit seed extract as a powerful in vitro agent against spirochetes and their cystic forms of Borrelia afzelii 44. Dipsacus sylvestris extract against Borrelia burgdorferi sensu stricto revealed growth inhibiting activity as well 45, whereas Sapi, et al, reported significant efficacy of leaf extracts from Stevia rebaudiana on all forms of Borrelia burgdorferi sensu stricto 46. Our recent study documented that other naturally occurring compounds like baicalein and luteolin, belonging to the flavones, are also potent against Borrelia sp.…”