Antibacterial activity of extracts obtained from plants of central Argentina

FUNES CHABÁN M.; JORAY M.B.; SOLÁ C.; BOCCO J.L.; PALACIOS S. M.; CARPINELLA M. C.

Encuentro; 3° Reunión Internacional de Ciencias Farmacéuticas RICIFA.; 2014

Bacterial infections are dramatically increasing every day for diverse reasons, mainly due to the development of resistance to conventional antibiotics. In this situation, and given the lack of new highly effective drugs, numerous extracts obtained from plants are being studied for chemical and anti-microbial characterization. Although many plant families are being investigated as sources of new antibiotics, the plant world is far from being totally explored and this also applies to the native flora from Argentina. Hence, extracts obtained from 69 native, introduced, adventive and naturalized plants from central Argentina were evaluated for their in vitro inhibitory activity on pathogenic bacteria with the aim of selecting the most active ones as new sources of effective antibiotics. The susceptibility of reference and clinical strains of Enterococcus faecalis, Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, methicillin-susceptible Staphylococcus aureus (MSSA) and gentamicin- and methicillin-resistant S. aureus (MRSA) was determined. Among these last, endemic strains of Hospital and Community Acquired S. aureus (HA-MRSA, CA-MRSA, respectively) obtained from patients from Córdoba hospitals, were included. Extracts from Aloysia citriodora and Lepechinia meyenii were the most active against all Gram positive and negative bacteria tested, being the last one the most potent (MICs and MBCs 0.062-1 and 0.250-2 mg/ml, respectively). Among the assayed extracts, those from Gaillardia megapotamica, Baccharis salicifolia, Wedelia glauca, Viguiera tucumanensis, Flourensia campestris, Elaphoglosum lorentzii and Angelphytum aspilioides showed high inhibition against HA-MRSA and CA-MRSA. The antibacterial activity shown by the plant extracts suggests that they could become as source of novel antibacterial drugs.