Chemical properties and antioxidant and antimicrobial activities of Slovenian propolis.
The chemical composition as well as the antioxidant and antimicrobial activities of two EtOH extracts of propolis (PEEs) from Slovenia were determined. EtOH was used as extracting solvent at 70 and 96%, providing the extracts PEE70 and PEE96, respectively. The extraction with 70% EtOH was more efficient than that with 96% EtOH, as the PEE70 was richer in total phenolic compounds than the PEE96. The Slovenian propolis was characterized by different phenolic acids and flavonoids. The PEE96 was slightly richer in three specific compounds, i.e., caffeic acid, ferulic acid, and luteolin, while all other substances detected showed higher contents in the PEE70. The PEE70 showed a stronger reducing power and ability to scavenge free radicals and metal ions than the PEE96. Both PEEs were in the main more effective against Gram-positive bacteria than against fungi and Gram-negative bacteria like Salmonella and Escherichia coli, with the exception of Campylobacter. The PEE96 decreased the intracellular oxidation in Saccharomyces cerevisiae in a dose-dependent manner. The antimicrobial activities and antioxidant properties were related to the total phenolic contents. The two PEEs have the potential for use as natural antimicrobial and antioxidant additives in foods.
Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia. ana.kramar@bf.uni-lj.si
Ana
A
Mavri
Helena
H
Abramovič
Tomaž
T
Polak
Jasna
J
Bertoncelj
Polona
P
Jamnik
Sonja
S
Smole Možina
Barbara
B
Jeršek
D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry* / Q000494:pharmacology*; D000975:Antioxidants / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D001424:Bacterial Infections / Q000188:drug therapy; D001516:Bees / Q000737:chemistry; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D005658:Fungi / Q000187:drug effects; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D006801:Humans; D008826:Microbial Sensitivity Tests; D009181:Mycoses / Q000188:drug therapy; D010636:Phenols / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D011429:Propolis / Q000737:chemistry*; D017524:Slovenia
D000890:Anti-Infective Agents; D000975:Antioxidants; D005419:Flavonoids; D010636:Phenols; D011429:Propolis