Assessment of Phenolic Content, Antioxidant Properties and Antimicrobial Activity of Flower and Leaf Extracts from Some Hypericum Species Affected by Wild Habitat Altitude

Abstract

In this study, determination of habitat altitude effect on the total phenolic contents, antioxidantand antimicrobial activities of flower and leaf extracts from Hypericum montbretii, H. orientale andH. perforatum species was aimed. The plants were collected randomly from forages (altitudes wereranged from 430 to 1105 m a.s.l.) located in Western Black Sea Region, Turkey. Antioxidantproperties of ethanolic extracts were determined with DPPH and ABTS assay and antimicrobialactivities of the extracts on Bacillus pumilis NRRL BD-142, B. subtilis NRRL B-209, B. licheniformisNRRL-B-1001, B. cereus NRRL B-3711, Staphylococcus aureus ATCC 33862, Pseudomonas aeruginosaATCC 27853, Listeria inocua ATCC 33090, L. monocytogenes ATCC 7644 and Escherichia coli ATCC25922 were examined. Total phenolic contents and antioxidant activities of Hypericum specieschanged depending on the habitat altitude. The antimicrobial activity of the ethanolic extracts wasevaluated by minimal inhibitory concentrations (MIC) method. Flower and leaf extracts exhibited abroad antibacterial spectrum, but they were not effective against Escherichia coli (ATCC 25922).Phenolic contents of all Hypericum species and antimicrobial activity of only H. perforatum extractswere significantly increased by altitude rising, but no positive correlation was detected in antioxidantactivity of extracts due to habitat altitude.