Detection of synergistic combinations of Baccharis extracts with Terbinafine against Trichophyton rubrum with high throughput screening synergy assay (HTSS) followed by 3D graphs. Behavior of some of their components.

RODRIGUEZ, MARÍA VICTORIA; SORTINO, MAXIMILIANO; IVANCOVICH, JUAN JOSE; PELLEGRINO, JOSE; FAVIER, LAURA; RAIMONDI, MARCELA; GATTUSO, MARTHA; ZACCHINO SUSANA

PHYTOMEDICINE

ELSEVIER GMBH

Año: 2013 vol. 20 p. 1230 - 1239

0944-7113

Forty four extracts from nine Baccharis spp. from the Caulopterae section were tested in combinationwith terbinafine against Trichophyton rubrum with the HTSS assay at six different ratios with the aim ofdetecting those mixtures that produced a ≥50% statistically significant enhancement of growth inhibition.Since an enhanced effect of a combination respective of its components, does not necessarily indicatesynergism, three-dimensional (3D) dose-response surfaces were constructed for each selected pair ofextract/antifungal drug with the aid of CombiTool software. Ten extracts showed synergistic or additivecombinations which constitutes a 22% hit rate of the extracts submitted to evaluation. Four flavonoidsand three ent-clerodanes were detected in the active Baccharis extracts with HPLC/UV/ESI-MS method-ology, all of which were tested in combination with terbinafine. Results showed that ent-clerodanesbut not flavonoids showed synergistic or additive effects. Among them, bacchotricuneatin A followed bybacrispine showed synergistic effects while hawtriwaic acid showed additive effects.