Marisia - Maros Megyei Múzeum Évkönyve 36/1. (2016)
Botany
In vitro assay of antibacterial activity of three medicinal plants [Bennett & Wallsgrove, 1994]. Phenolic acids (for example ferulic acid, gallic acid) have been repeatedly implicated as natural antioxidants in herbs [Zheng & Wang, 2001]. Flavonoids Fig. 7: MIC of ethanol extracts of A. absinthium against MDR Gram negativ bacteria measured via single-wavelength spectrophotometry at 620 nm are known to be synthesized by plants in response to microbial attack by the hydroxylation of phenolic compounds fact which justifies efficacy against a wide range of microorganisms. The antibacterial activity is probably due to their ability to react with extracellular and soluble proteins bacterial cell wall leading hence leading to their disintegration [Idris, 2009]. Multiple hydroxyl groups of flavonoids they have higher antioxidant activities against peroxyl radicals than do phenolic acids. However, the flavonoid glycosides (including rutin) usually have low anioxidant activity [Zheng & Wang, 2001]. The results show that the degree of inhibition is variable depending on the type of extract against various microorganisms. Thus, the extract of E. caryopbyllata which has the largest antioxidant activity, being maintenance and the highest content of phenolics, had antibacterial activity against all MDR strains. In addition, from the analysis of the profile of resistance of the MDR strain to antibiotics used, we can suggest that the activity of certain potential antimicrobial compounds in herbs extracted, to be achieved by different mechanisms from those of the antibiotics used. Though the extracts of A. absinthium and J. nigra have not had antibacterial activity against all strains analyzed, they are nevertheless medical interest. J. nigra has been reported for the first time in this paper as having antibacterial role against MDR Gram-negative strains. Conclusions The antibacterial activity of the herbs extracts is linked with the chemical composition of the synthesis of the compounds resulting from the secondary metabolism of plants and the concentration of these compounds. Thus, the antibacterial activity of the extract of E. caryophyllata can be attributed to the high content of phenols and extract from J. nigra to the flavonoid content which is predominant. The hydroethanolic extracts of E. caryopbyllata, J. nigra and A. absinthium could pose a important support in the industrial production of the new drugs in the therapy of kidney infections caused by MDR Gram negative bacteria. 49 500 250 125 62.5 31.25 15.625 7.831 3.9 1.953 0.976 P.mirabilis 11 » A.baumannii 115 "• P.aeruginosa 111 K.pneumoniae 115 » P.aeruginosa 120 ■» K.pneumoniae 114 * A.baumannii 15 .......P.aeruginosa 125 • A.baumannii 125 E p.aeruginosa 11112 '• P.aeruginosa 11115 « M-
