Anti-oxidative and antimicrobial activities of Hieracium pilosella L. extracts

摘要

The anti-oxidative and antimicrobial activities of different extracts from Hieracium pilosella L. (Asteraceae) whole plant were investigated. The total dry extracts were determined for all the investigated solvents: methanol, dichloromethane, ethyl acetate and dichloromethane:methanol (9:1). It was found that the highest yield was obtained by extraction with methanol (12.9 g/100 g of dry plant material). Qualitative and quantitative analysis were performed by the HPLC method, using external standards. Chlorogenic acid, apigenin-7-O--glucoside and umbelliferone were detected in the highest quantity in the extracts. The qualitative and quantitative composition of the extracts depends on the solvent used. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging effect of the extracts was determined spectrophotometrically. The highest radical scavenging effect was observed in the methanolic extract, both with and without incubation, EC_(50) = 0.012 and EC_(50) = 0.015 mg ml~(-1), respectively. The antimicrobial activities of the extracts towards the bacteria (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus sublilis, Salmonella enteritidis and Klebsiella pneumoniae) and the fungi (Aspergillus niger and Candida albicans) were determined by the disc diffusion method. The minimal inhibitory concentrations were determined for all the investigated extracts against all the mentioned microorganisms.%Испитивана jе антиоксидативна и антимикробна активност различитих екстраката до-бщених из целе билке Hieracium pilosella L.(Asteraceae). Укупни суви екстракти одреhени су за све екстракте, метанолни, дихлорметански, етилацетатни и дихлорметан:метанолни (9:1) и показано jе да jе наjвеhи принос постигнут са метанолом (12.9 g/100 g сувог бнльног материала). Квалитативни и квантитативни садржаj jс анализиран помоhу HPLC методе кориш-hенем екстерних стандарада. Идентификоване су три наjзастушьениjе компоненте у екс-трактима: хлорогенска киселина, апигенин-7-O-глукозид и умбелиферон. Установлено jе да квалитативни и квантитативни састав екстраката зависи од врете растварача. Способност неутралисана 1,1 -дифенил-2-пикрил-хидразил (БРРН) радикала екстрактима одреhена jе спек-трофотометриjски. Наjвеhа способност неутралисагьа радикала остваруjе се метанолним екс-трактом са инкубащjoм и без не (EC_(50) = 0.012, односно 0.015 mg ml~(-1)). Антимикробна активност на бактериjе (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacil-lus subtilis, Salmonella enteritidis и Klebsiella pneumoniae) и пьиве (Aspergillus niger и Candida albicans) одреhена jе применом диск дифузионе методе. Одреhене су минималне инхиби-торне концентращнjе (MIC) за све испитиване екстракте за наведене микроорганизме.