Ellagitannin HeT obtained from strawberry leaves is oxidized by bacterial membranes and inhibits the respiratory chain

MARTOS, GUSTAVO G.; MAMANI, ALICIA; FILIPPONE, MARÍA PAULA; ABATE, PEDRO O.; KATZ, NESTOR E.; CASTAGNARO, ATILIO P.; DIAZ RICCI, JUAN C

FEBS Open Bio

WILEY-V C H VERLAG GMBH

Lugar: New Jersey, USA; Año: 2017 vol. 8 p. 211 - 218

Plant secondary metabolism produces a variety of tannins that have a wide range of biological activities, including activation of plant defences and antimicrobial, anti-inflammatory and antitumoral effects. The ellagitannin HeT (1-0-galloyl-2,3;4,6-bis-hexahydroxydiphenoyl B-D glucopyranose) from strawberry leaves elicits a strong plant defence response, and exhibits antimicrobial activity associated to the inhibition of the oxygen consumption, but its mechanism of action is unknown. In this paper we investigate the influence of HeT on bacterial cell membrane integrity and its effect on respiration. A B -galactosidase unmasking experiment showed that HeT does not disrupt membrane integrity. Raman spectroscopy analysis revealed that HeT strongly interacts with the cell membrane. Spectrochemical analysis indicated that HeT is oxidized in contact with bacterial cell membranes, and functional studies showed that HeT inhibits oxygen consumption, NADH and MTT reduction. These results provide evidence that HeT inhibits the respiratory chain.