Phenolic Content, and Antioxidant and Antimicrobial Activities of Crataegus Oxyacantha L (Rosaceae) Fruit Extract from Southeast Serbia

Purpose: The aim of this work was to determine the content of total phenols, total flavonoids, anthocyanins, as well as antioxidant and antimicrobial activities of hawthorn ( Crataegus oxyacantha L.) alcohol, hydroalcohol and aqueous extracts. Methods: The content of total phenols, flavonoids and anthocyanins of the alcohol, hydroalcohol and aqueous extracts of hawthorn were determined using spectrophotometric methods. Antioxidant assay was based on the measurement of DPPH absorbance at 517 nm caused by the reaction of DPPH with the test sample. Antimicrobial activity was evaluated by measuring the zone of inhibition against selected test microorganisms: Bacillus subtilis , Staphylococcus aureus , Escherichia coli , Pseudomonas aeruginosa , and Salmonella abony while antifungal activity was tested against two organisms: Aspergillus niger and Candida albicans . Results: The results of spectrophotometric investigations indicate that the content of total phenol compounds in the investigated extracts varied from 2.12 to 30.63 mg GAE g-1 of fresh hawthorn sample. The content of anthocyanins ranged from 0.3207 to 3.168 mg of cyanidin-3-O-glucoside g-1 of fresh hawthorn fruit. The fruit extracts showed high antioxidant activity with DPPH radical transformation value as high as 89.9 % in the methanol-water (50/50, v/v%)) extract. The ethanol extract exhibited antimicrobial activity against all test microorganisms except two, Bacillus subtilis and Staphylococcus aureus, and one species of fungi, Aspergillus niger.Flavonoid structure influenced the extract’s selectivity towards Gram-positive and Gram negative bacteria. Conclusion: Extracts of the fruit of Crataegus oxyacantha L. can be used as natural antioxidant and antimicrobial preparations

Phenolic Content, and Antioxidant and Antimicrobial Activities of Crataegus Oxyacantha L (Rosaceae) Fruit Extract from Southeast Serbia

Total phenolic and flavonoid contents of different extracts of Papaver rhoeas L. were examined. High contents of total phenolic compounds (9.73 -19.91 mg GAE/g of fresh petals) and total flavonoids (7.904 -11.45 mg QE/g of fresh petals) were determined. Red pigment present in the flowers of P. rhoeas L. originates from anthocyanins, which may act as natural antioxidants. Anthocyanins content in the investigated extracts is very unified and ranged from 4.72 to 5.193 mg of cyanidin-3-O-glukoside/g of fresh petals. The antioxidant activity of different extracts was tested using the spectrophotometric method by means of the ability of extracts to scavenge stable 1,1-Diphenyl-2-picrylhydrazyl (DPPH). All tested extracts exhibited strong scavenging activity against DPPH radicals, that is higher then 80%. Total phenolic and flavonoid contents may be related to the percentages of the scavenging activity of DPPH assay (estimated correlation coefficient are R 2 = 0.965 and 0.752, respectively). The ethanol extract of P. rhoeas L. showed antimicrobial activity against the yeast Candida albicans, and all tested bacteria except Bacillus subtilis. This paper suggests that the investigated extracts of plant P. rhoes L. could be potentially applied as an antioxidant and antimicrobial agents. Key words: Papaver rhoeas L., phenolic content, anthocyanins content, flavonoid content, antioxidant activity, antibacterial activity. INTRODUCTION Papaver rhoeas L. (Papaveraceae) is an annual herb indigenous to numerous regions in the world. In traditional medicine until synthetic drugs are developed, extracts of this plant have been used for the treatment of a wide range of diseases including inflammation, diarrhea, sleep disorders and, moreover, for cough, analgesia and also the reduction of withdrawal signs of the opioid addiction. It is also claimed that plant P. rhoeas exhibits sedative, narcotic, and emollient effects ( In the present paper, the evaluation of P. rhoeas L. from Southeast Serbia with respect to phenolic content and the antioxidant data of different extracts obtained from plant petals are reported. As it is stated earlier, numerous polyphenols are known to possess excellent antioxidant effects, especially in vitro, and the amount of total polyphenols present in a plant has been suggested to correlate with the antioxidant activity. Therefore, this work represents the first report on phenolic content and related antioxidant activity of the extracts of P. rhoeas L. from Southeast Serbia. Antimicrobial activity of ethanol extract of P. rhoeas was investigated, too. EXPERIMENTAL Plant material The plant was collected at bloom stage in few villages from the South-eastern Cape Province of Serbia in July, 2009. The plant was firstly identified by its vernacular name and later validated by voucher number of the deposited herbarium specimens at the Department of Botany (University of Novi Sad, Serbia). Preparation of plant extracts The fresh petals of P. rhoeas L. were milled by an appropriate blender. Three samples (each weighed 2.0 g) were separated from the previously homogenized plant material, and extracted with the desired volumes (30, 20 and 20 ml, respectively) of the chosen solvents (methanol, ethanol, methanol-water mixture, ethanol-water mixture and water) three times in the further course. Samples were mixed in an ultrasound bath during the extraction procedure. Such obtained extracts were filtered using the Buchner funnel and Whatman No. 1 filter paper. Solid residues were rinsed for several times in order to gain transparent extracts. Finally, the obtained plant extracts were collected in graduated flask of the same volume of 100 ml. Chemicals and reagents 1,1-Diphenyl-2-picrylhydrazyl (DPPH), quercetin and AlCl3 were purchased from Sigma Chemical Co. (St. Louis, MO, USA). FolinCiocalteu's phenol reagent and sodium carbonate were purchased from Merck Chemical Suppliers (Darmstadt, Germany). Sodium chlorate buffer (pH 1.0) and acetate buffer (pH 4.5) were purchased from the same producer. The other used chemicals including solvents were of analytical grade. Determination of the total phenolics Total phenolic contents in the extracts were determined by the modified Folin-Ciocalteu method Determination of the total monomeric anthocyanins The total monomeric anthocyanin content in the plant extracts was determined using the pH-differential method previously described by (1) Content of the monomeric antocyanin pigment (MAP) was calculated by Equation 2