Leaves and fruits of Schinus areira growing in jujuy, a potential source of antibacterial compounds

LILIANA SOLEDAD CELAYA; MARIA SOLIS SANCHEZ; ANA CRISTINA MOLINA; CARMEN INES VITURRO; SILVIA MORENO

Mar del Plata

Congreso; X Congreso Argentino de Microbiologia General SAMIGE 2014; 2014

Sociedad Argentina de Microbiología General

There is an urgent need to replenish our arsenal of anti-infective agents given the dramatic increase of antibiotic resistance around the world. Natural products, as the secondary metabolites ubiquitously distributed in higher plants, are a major source of chemical diversity and have provided important therapeutic agents for many bacterial diseases. These compounds have important roles as defense against plant pathogens and animal herbivore aggression and as response to various abiotic stress conditions. They are gaining increasing interest and can be rationally selected for antibacterial testing based on ethnomedicinal use. We investigate the antibacterial activity of the native three Schinus areira L. (synonymous: Schinus molle L. var. areira DC. (aguaribay). The leaves and fruits of this plant widely distributed in the northwestern of Argentina4 have been used as medicines by indigenous peoples historically as antibacterial, antifungal and antirheumatic. However, the antimicrobial activity of leaves and fruits of S. areira has not been deeply investigated, so limiting the use of their derivatives in the modern medicine. The antibacterial performance of essential oils and ethanol extracts isolated from leaves and fruits of several S. areira specimens was performed by the microplate bioassay as described. The chemical principal component of essential oils from S. areira fruits determined by GC/FID and GC/MS were limonene, α-phelandrene, β-phelandrene, sabinene and myrcene. The strongest antibacterial activity against Staphylococcus aureus was exhibited by the fruits oils rich in limonene and sabinene (MIC values <10 μL/mL). When the antibacterial effect of ethanolic leaves and fruits extracts obtained by ultrasound-assisted extraction was determined, a moderate activity against sensitive and meticillin resistant S. aureus was observed (MIC50 100-150 μg/mL). The leaves extract was more potent than the fruits extract. To understand the interactions between the compounds of the leaves extracts we use the checkerboard method for detecting interactions between bioactives (non-volatile phenolic compounds), as described previously. Results showed that the three ethanolic extracts assayed showed smaller antibacterial activity than that of the sum of the individual substances against S. aureus. This antagonistic effect suggested that the bioactive/s in the ethanolic extracts target the same sites in the bacterial cell, at least again the bacteria studied. In conclusion: the present results highlight the presence of some constituents with interesting antibacterial activity in both essential oils and ethanol extracts of leaves and fruits of S. areira.