Determination of Phenolic Contents, Antioxidant and Antibacterial Activities of Strawberry Tree (Arbutus unedo L.) Leaf Extracts

Abstract

Aims: This study was designed to evaluate the antibacterial and antioxidant activities of methanolic, ethanolic, ethyl acetate and n-hexanic extract from the leaves of Strawberry tree (Arbutus unedo L.) growing in Morocco. Study Design: Determination of total phenol and flavonoids content, in vitro antioxidant activity and antibacterial study of extracts.

Phenolic extracts of Centaurium erythraea with novel antiradical, antibacterial and antileishmanial activities

“…The extract was diluted to the concentration of 1 mg /mL, and aliquots of 100 μL or a standard solution of gallic acid (20, 40, 60, 80 and 100 mg/L) were mixed with 500 μL of Folin-Ciocalteu reagent (previously diluted 10-fold with distilled water) and 400 μL of Na 2 CO 3 (7%). After 40 min of incubation at room temperature, the absorbance was measured at 760 nm and compared to a blank sample [11]. The TPCs content expressed as gallic acid equivalent (GAE) was calculated based on the calibration curve using the following linear equation [33] …”

“…The TFC of plant extracts was measured by the aluminum chloride (AlCl 3 ) colorimetric assay [11]. 1 mL of the extract (1 mg/ mL in methanol) or a standard solution of quercetin (20,40,60, 80 and 100 mg/mL) was mixed with 1 mL of 2% AlCl 3 in methanol.…”

“…Briefly, aliquots (0.2 mL) of various concentrations (62.5-1 000 μg/ mL) of the plant extracts samples were added to 1.8 mL of a 0.004% methanolic solution of DPPH. After 30 min of incubation at room temperature, the absorbance was measure against a blank at 517 nm [11]. The percentage (%) to scavenge DPPH radical was calculated by the following formula [34]: DPPH scavenging activity (AA in %) = [(Ac -At)/Ac] × 100 where Ac is the absorbance of the control (without extract), and At is the absorbance of the test (with extract).…”

“…The concentration of extract that provided 50% of DPPH inhibition (IC 50 ) was calculated from the graph plotted of inhibition capacity (AA in %) against extracts and standards concentrations using linear regression equations [11].…”

“…The most important sources of antioxidant, antibacterial and antiparasitic molecules are the natural bioactive products of plants such as flavonoids and phenolic compounds that have known for their several biological activies such as an antibacterial effect [10][11][12], suppress the production of free radicals [11,[13][14][15][16][17], delay oxidative stress reactions and have an important role against one of the world major human diseases like cancer [18]. In the search for such natural products and modern drugs, medicinal plants play an important role [19][20][21][22][23][24].…”