Planta Med 2008; 74 - PK6
DOI: 10.1055/s-0028-1084975

In vitro antibacterial activity of Antennaria dioica L. and evaluation of synergism between plant extract and preservatives

S Dragana 1, L Čomić 1, O Stefanović 1, S Solujić- Sukdolak 2
  • 1Faculty of Science, Department of Microbiology, Radoja Domanovica 12, 34 000 Kragujevac, Serbia
  • 2Faculty of Science, Department of Biochemistry, Radoja Domanovica 12, 34 000 Kragujevac, Serbia

The antibacterial activity of the aqueous extract of Antennaria dioica (L.) (Asteraceae) was tested in vitro against selected food-spoiling bacteria. The following species of bacteria were tested: Agrobacterium radiobacter var. tumefaciens, Bacillus subtilis, Bacillus mycoides, Escherichia coli, Enterobacter cloacae, Erwinia carotovora, Pseudomonas aeruginosa, Proteus sp. and Staphylococcus aureus. Water extract manifested antibacterial activity against all of the tested species. The strongest antibacterial activity was against Bacillus mycoides, Erwinia carotovora and Proteus sp. (MIC was 12, 5mg/ml). The most resistant species wasStaphyloccocus aureus. In vitro synergism between water extract of Antennaria dioica L. and selected preservatives (sodium benzoate, sodium nitrite, potassium sorbate) was studied by the checkerboard assay method [1]. In vitro synergism between water extract with sodium benzoate was determined in relation to Bacillus subtilis, Bacillus mycoides, Erwinia carotovora; with sodium nitrite in relation to Bacillus subtilis, Bacillus mycoides, Agrobacterium radiobacter var. tumefaciens, Erwina carotovora; and with potassium sorbate was determined in relation to Erwinia carotowora, Proteus sp. The synergism between water extract and preservatives was determined by calculating the fractional inhibitory index. Types of effects were classified as follows: FIC ≤0.5, synergism; FIC 0.5–1, additive effect; FIC 1–4, indifferent effect; and FIC >4, antagonism [2]. Synergism was established at plant extract and preservative concentrations corresponding to 1/4 MIC and lower. In present work FIC fluctuated from 0.28–0.50. The results of this work indicate the possibility of using synergism between Antennaria dioica L. and tested preservatives to more effective conservation of foods.

References: 1. Bayani, M.M., Azanza, P.V (2005) Food Sci.Technol. Res 11: 214–221.

2. Nostro, A. et al. (2006) Phytotherapy Res. 20: 187–190.