Chemical Composition, Antioxidant and Antibacterial Activities of Extracts Obtained from the Roots Bark of Arbutus Andrachne L. a Lebanese Tree
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View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by International Journal of Phytomedicine International Journal of Phytomedicine 8 (2016) 104-112 http://www.arjournals.org/index.php/ijpm/index Original Research Article ISSN: 0975-0185 Chemical composition, antioxidant and antibacterial activities of extracts obtained from the roots bark of Arbutus andrachne L. a Lebanese tree. Emna Abidi1, Jean Habib2, Touhami Mahjoub3, Feten Belhadj4, Meriem Garrab5 and Assem Elkak1* *Corresponding author: A b s t r a c t Emna Abidi Context and purpose of the study: The leaves, fruits, barks and roots of Arbutus andrachne L (A. andrachne), have been adopted to have high therapeutic value resulting from the presence of antioxidant compounds such as flavonoids, phenolic and tannins. In the present work, three 1Laboratoire de Valorisation des Ressources extracts obtained from A. andrachne roots bark were evaluated for their antioxidant and Naturelles et Produits de Santé (VRNPS), antibacterial activities .The total phenolic content, flavonoid, condensed tannins and EDST, Faculty of Pharmacy, Lebanese anthocyanins were determined in order to correlate them with the antioxidant activity of University, Hadath, Lebanon. extracts. 2Laboratoire de Recherche et Main findings: The highest amounts of phenolic and tannins were found in the ethyl-acetate, Développement des Médicaments et des while the anthocyanins ones were highly observed in the methanol-water extract. The lowest Produits Naturels, (RDMPN). EDST, Faculty IC50 values for DPPH (0.6 µg/mL), and metal chelating assay (13.45µg/mL) were recorded in of Pharmacy, Lebanese University , Hadath, the ethyl-acetate extract and the methanolic one respetively. Gram positive bacteria (S. aureus Lebanon. and E. faecalis) were more susceptible to the antimicrobial potential of the methanol extract, 3Human Genetics and Multifactorial while E.coli and P. aeruginosa as Gram negative bacteria turned out to be more resistant to Diseases, Faculty of Pharmacy Monastir the same extract. The ethyl-acetate extract was more effective on E. faecalis than on S. 5080 Ibn Sina Street , Tunisia. aureus; while E. coli and P. aeruginosa were the most resistant to this extract. 4,5Laboratory of Protein Engineering and Brief summary and potential implications: An appropriate dose of antioxidants derived from A. Bioactive Molecules (LIP-MB LR11ES24) andrachne bark of the roots extracts in the human diet can help to avoid the risk of contracting INSAT, BP 676 –Tunis Cedex 1080,Tunisia. diseases where ROS are involved in the pathogenesis. In fact, phenolic compounds in these University of Carthage. extracts are among the natural antioxidants being studied by the scientific community due to their biological properties, e.g., antioxidant and antimicrobial activities. Keywords: Arbutus andrachne L., Ericaceae, roots bark extracts, antioxidant activity, antibacterial activity vitamins, phenols, flavonoids, and endogenous metabolites which Introduction have been identified as free radicals or active oxygen scavengers [5]. Phenolic compounds are among the natural antioxidants being Nowadays, growing literature has emerged regarding reactive intensively studied by the scientific community due to their oxygen species (ROS) and free radicals [1]. Several studies have antioxidant and antimicrobial activities [6]. discussed the deleterious consequences of ROS and their Flavonoids frequent components of the human diet, and exhibit implications in diseases [2]. Fortunately, living systems can protect pharmacological effects that are linked to their known biological themselves against the harmful effects of ROS and free radicals via functions in cancer and cardiovascular diseases as well as their natural defense mechanisms such as enzymes and antioxidants role as antioxidants and anti-inflammatory components [7]. In the [3]. The antioxidant beneficial effect can be explored in food Mediterranean region, the Ericaceae family has two evergreen nutrition by using plants as a source of antioxidants [4]. Plants Arbutus L., species with edible fruits: A. andrachne, and Arbutus contain many natural antioxidant compounds such as carotenoids, unedo L (A. unedo). A. andrachne also called the strawberry tree, This work is licensed under a Creative Commons Attribution 3.0 License. Abidi et al. International Journal of Phytomedicine 8 (1) 104-112 [2016] is well known for its biological properties and has traditionally been The TOF extract was prepared by maceration of 100 g of ground used as an alternative medicine, [8, 9]. The fruit of this tree has root bark in 500 ml of an acetone-water mixture (2/3) (v/v). The antiseptic, diuretic and laxative effects, where the leaves have product of the maceration was then filtered and cleared of acetone astringent, urinary tract antiseptic, anti-diarrheal and depurative by evaporation under reduced pressure until an aqueous solution properties [10].This effect is likely mediated by its antioxidant was obtained and saturated by NaCl (400g/l) upon being agitated activity. Previously, the antioxidant activity and the total phenolic for overnight. The obtained precipitate was eliminated by filtration content was determined only for the fruit part of A. andrachne[11]. on sintered glass which allows passage of a crystal clear liquid Given the traditional use of A. andrachne and the poorly containing TOF. The following experimental step consists of the characterized phytochemical contents of this tree, it is of great extraction of TOF by using ethyl acetate in which the TOF are importance to investigate the biological activities of different soluble and can be easily extracted. The various ethyl acetate extracts obtained from other parts of the plant. Interestingly, the extracts were combined, dehydrated by agitation with the elevated levels of phenolic compounds in the A. andrachne fruits anhydrous sodium sulfate, and then filtered, concentrated under suggests that an antimicrobial effects could also be displayed. In reduced pressure to a final volume of approximately 20 ml. For the this study we at: i) determining the phenolics, flavonoids, total TOF precipitation, 5 volumes of chloroform were added to the tannins and total anthocyanins in extracts obtained from the bark concentrated extract under agitation. A fluffy precipitate was of the roots of A. andrachne; ii) evaluatiing the antioxidant and formed followed by filteration on a sintered glass and kept to dry antibacterial activities of the previously mentioned constituents and under the hood. iii) comparing the obtained results with those previously described for A. unedo. Hydromethanolic extract (E3) Material and methods The extract (E3) was obtained from a liquid-liquid extraction of (E1) Extract: For this purpose, 82 g of root bark were extracted similarly to (E1). After evaporation, the methanolic extract was subjected to Chemicals a liquid-liquid extraction by adding an equal volume of distillated water. Immediate separation of a precipitate was observed, and All chemicals used were of analytical grade and were purchased then the (E3) extract was filtered, concentrated and dried in from Sigma-Aldrich (St. Louis, MO, USA). vacuum. Plant materials Determination of total phenols, flavonoids, condensed tannins and anthocyanins Fresh bark(s) from the roots of the Lebanese A. andrachne were collected in September 2013 in the region of Deir Al Kamar (at Total phenols, flavonoids, condensed tannins and anthocyanins about 850m in the Mount Lebanon region). Voucher specimens quantifications in the different extracts were determined according were deposited in the herbarium of the Faculty of Pharmacy to Singleton and Rossi [12], colorimetric assay of Kim et al [13], the o (voucher n . EADR13Aar). method of Sun et al [14] and a modified pH differential method previously described [15] respectively. All experiments were carried Preparation of the extracts out in triplicate and gallic acid, quercetin, catechin and anthocyanidins respective equivalent values were reported as X ± The barks from the roots were shade dried and powdered using an SD of triplicates. electric blender. The obtained mass as well as the extraction yield for the different extracts are shown in Table 1. Antioxidant activity Methanolic extract (E1) Ferric Reducing/Antioxidant Power (FRAP) assay 82 g of powdered barks of roots were placed into the extractor of a The reducing power was determined according to the experimental Soxhlet. The extraction was carried out by using methanol. At the procedure described by Berker et al [16]. The absorbance was end of the extraction the methanol extract was concentrated by calculated at 700 nm and compared with ascorbic acid as positive evaporation, frozen and then lyophilized. control (higher absorbance readings indicate higher reducing power). The data are reported as the average of three Total Oligomeric flavanols (TOF) extract (E2) measurements given as ± SEM. PAGE | 105 | Abidi et al. International Journal of Phytomedicine 8 (1) 104-112 [2016] Diphenyl-1-picrylhydrazyl (DPPH) radical- The bark roots extracts of A. andrachne were individually evaluated scavenging activity for their antibacterial activity against four types of microorganisms: Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATTC27950) Staphylococcus aureus (ATCC 25923) and The DPPH is a stable free radical characterized by its maximum Enterococcus faecalis (ATCC 2921). Microbial strains were absorption at 517 nm. A control was prepared for each