Antagonism between Resveratrol and antimicrobian agents

MAIRA GASPAR TOSATO; PATRICIA L. SCHILARDI; MÓNICA FERNÁNDEZ LORENZO DE MELE; ANDRÉS H. THOMAS; ALEJANDRO MIÑAN; CAROLINA LORENTE

Villa Carlos Paz , Córdoba, Argentina.

Congreso; XIII Encuentro Latinoamericano de Fotoquímica y Fotobiología (XIII ELAFOT); 2017

ELAFOT

Several antimicrobial agents, such as antibiotics and sensitizers used inphotodynamic therapy, are efficient to generate reactive oxygen species (ROS)in order to eliminate undesired pathogenic microorganisms that are harmful tohealth.Among natural antioxidants reverastrol (RSV) is efficient to preventdamage from ROS. However, the consequences of the administration of RSV duringan antimicrobial treatment are unknown. To investigate possible antagonistic orsynergistic effects of RSV during antibiotic therapy (levofloxacin, LVX) or aphotodynamic inactivation (PDI) therapy (visible radiation and methylene blue,MB), the elimination of Staphyloccocusaureus of a planktonic culture was evaluated in the presence of RSV. Results shows that the antimicrobial capacity of these therapies issignificantly diminished when LVX or MB are co-administered with RSV. In thecase of LVX, the presence of RSV increases 20-fold the bacterial survival comparedwith LVX (0.125 mg/ml) alone. Moreover co-administration of both MB andRSV decrease MB efficacy, which improve bacteria survival from 10 to 1000-foldin the whole range of MB concentration tested (6.25 to 50 mg/ml).  The results presented in this work indicate that the consumption of RSVduring an antimicrobial treatment is strongly discouraged. Finally, consideringthat the microbiocidal activity of host defenses (neutrophils, macrophages) is alsomediated by ROS, the topical addition of RSV, may also affect the normal controlof pathogens of the human body. Therefore this work highlight the importance ofthe evaluation of possible antagonistic effect when an antimicrobial agent withROS-mediated action is co-administrated with RSV. AcknowledgementsThe present work was partially supported byConsejo Nacional de Investigaciones Científicas y Técnicas (CONICET-Grant PIP112-200901-00425), Agencia de Promoción Científica y Tecnológica (ANPCyT-GrantPICT-2012?0508), Universidad Nacional de La Plata (UNLP-Grant X712). M. G. T. thanks CONICET for post-doctoral researchfellowships. [1] D. Dwyer, M. Kohanski, J. Collins, CurrOpin Microbiol, vol. 12, pp. 482?9, 2009.[2] A.Miñán, C. Lorente, A. Ipiña, A. H. Thomas, M. Fernández Lorenzo de Mele, and P.L. Schilardi, Biofouling, vol. 31, no. 5, pp. 459?68, 2015.[3] Vecchio, A. Gupta, L. Huang, G. Landi, P. Avci, A. Rodas,and M. R. Hamblina, Antimicrob. Agents Chemother., vol. 59, no. 9, pp. 5203?5212, 2015.