Marisia - Maros Megyei Múzeum Évkönyve 36/1. (2016)

Botany

Luminifa ROMAN et alii

of North America. The only studies that would show the antibacterial activity of species from family Juglandaceae make reference to J regia. The antibacterial activity of extracts from leaves of J. regia was remarkable against Gram positive versus Gram negative bacteria which showed inactivity [Pereia et al, 2007].

Materials and methods

The strains MDR Gram negative were isolated from renal infections of patients hospitalized at “Theodor Burghele” Hospital, Bucharest. The identification of bacterial strains and antibiotic resistance profile were performed using a compact automated VITEK 2 system (BioMérieux Inc, Durham, NC) according to the manufacturer’s instructions, in the hospital laboratory.

Obtaining hydroethanolic extract of herbs and antibacterial testing

The leaves of A. absinthium and of J. nigra were collected during the month of August 2014 from the Botanical Garden Bucharest. Buds of E. caryophyllata were purchased from an Arab spice grocery. The leaves were shade-dried for 10 days. 300 g of herbs were transformed into dust using a grinder. We poured over the powder, 700 mL solution (200 mL of distilled water and 500 mL ethanol). The solution thus obtained was kept in an amber glass container at a temperature of 4°C while stirring every day. After ten days the solution was placed in a rotary evaporator for 10—15 minutes after which the supernatant was removed using a Whatman no. 1 filter. Finally, we obtained stock solution of which serial dilutions were prepared. For the calculation of MIC (Minimum Inhibitory Concentration) we used sterile sets of disposable 96-well flat bottom plastic plates, containing 12 rows, with a capacity of approximately 300 pL/well. For columns 2-12, 100 pL of nutrient broth was distributed, and for the first column 180 pL per well were distributed. Of the stock solution obtained from extract of cloves, we distributed 20 pL per well in the first column, mixed it with 180 pL of medium, then we took in pipette 100 pL of mixes and we pipetted into next column, repeating the same operation up to the tenth column, then threw the 100 pL mixes. Those were the decimal dilutions. In the last two columns extract of clove was not pipetted. After this stage, 20 pT per well of bacterial suspension adjusted to 0.5 McFarland units were distributed in columns 1-11, the last column (12) being negative control. The plates were placed in an incubator at 37°C for 24 hours. MCI was established macroscopically, as the last concentration at which no growth of the microbial environment was observed, and the appearance of turbidity was read spectrophotometrically as the absorbance at 620 nm.

Quantitative analysis of the antibacterial compounds of hydroethanolic

extract of herbs

For the measurement of antioxidant activity we used ABTS (2,2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) assay, a method based on electron transfer reactions. The capacity to scavenge free radicals of hydroethanolic extract of cloves was evaluated by measuring the absorbance of the sample treated with radical cation ABTS"+. Calculation of the total content of phenolic compounds, was performed according to protocol Folin-Ciocalteu. The total flavonoids content of extracts was determined by treating 0.5 mL of extract appropriately diluted with distilled water with 0.4 mL of 25 g/L A1C13 solution, 0.5 mL of 100 g/L CH3COONa solution and 4 mL distilled water. The absorbance measurements were performed using a

44