Antimicrobial and Antioxidant Activities of Plants from Northeast of Mexico

Abstract

Traditional medicine has a key role in health care worldwide. Obtaining scientific information about the efficacy and safety of the plants from our region is one of the goals of our research group. In this report, 17 plants were selected and collected in different localities from northeast Mexico. The dried plants were separated into leaves, flowers, fruit, stems, roots and bark. Each part was extracted with methanol, and 39 crude extracts were prepared. The extracts were tested for their antimicrobial activity using three Gram-negative bacterial strains (Pseudomonas aeruginosa,Klebsiella pneumoniaeandAcinetobacter baumannii), three Gram-positive bacterial strains (Enterococcus faecalisand twoStaphylococcus aureusstrains), and seven clinically isolated yeasts (Candida albicans,C. krusei,C. tropicalis,C. parapsilosisandC. glabrata); their antioxidant activity was tested using a DPPH free radical assay. No activity against Gram-negative bacteria was observed with any extract up to the maximum concentration tested, 1000 μg ml−1. We report here for the first time activity ofCeanothus coeruleusagainstS. aureus(flowers, minimal inhibitory concentration (MIC) 125 μg ml−1),C. glabrata(MICs 31.25 μg ml−1) andC. parapsilosis(MICs between 31.25 and 125 μg ml−1);Chrysanctinia mexicanaagainstC. glabrata(MICs 31.25μg ml−1);Colubrina greggiiagainstE. faecalis(MICs 250 μg ml−1) andCordia boissieriagainstC. glabrata(MIC 125μg ml−1). Furthermore, this is the first report about antioxidant activity of extracts fromCeanothus coeruleus,Chrysanctinia mexicana,Colubrina greggiiandCyperus alternifolius. Some correlation could exist between antioxidant activity and antiyeast activity against yeasts in the speciesCeanothus coeruleus,Schinus molle,Colubrina greggiiandCordia boissieri.