Cell Viability Effects and Antioxidant and Antimicrobial Activities of Tunisian Date Syrup (Rub El Tamer) Polyphenolic Extracts

Abstract

The aqueous-acetone polyphenolic extract of the traditionally derived date syrup, known as "Rub El Tamer", was analyzed using RP-HPLC-DAD and ESI-MS. The phenolic content of the extract was 394.53 ± 1.13 mg per 100 g of syrup with caffeoylsinapylquinic acid as the most abundant compound (72.23%). The extract exhibited strong antioxidant activities as evaluated using the ABTS (2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)), DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric reducing antioxidant power) methods. The extract antimicrobial potential against a range of microorganism strains showed that Staphylococcus aureus, Staphylococcus epidermidis, and Bacillus cereus were the most sensitive bacteria with MBC in the range of 0.5-0.05 mg/mL. Furthermore, in the presence of the syrup extract (8.18-131 μg/mL), the Human SH-SY5Y neuroblastoma and the 3T3 fibroblast cell lines showed dissimilar reduction of viability suggesting a higher cytotoxic effect against tumorigenic cells. Our results provide new insights into date syrup characterization which should stimulate further studies of this hot desert resource.

Scavenging Activity, Anti-Inflammatory and Diabetes Related Enzyme Inhibition Properties of Leaves Extract from some Varieties of <i>Phoenyx dactylifera l.</i>

“…Recently some studies that supported these results were reported [28,33,34]. Thus, our study was undertaken considering the leaves of three varieties.…”

Classification and assessment of antioxidant activity and phenolic content of different varieties of date palm (Phoenix dactylifera) fruits from Iran

“…The spectrophotometer has been calibrated using methanol as a reference. The Trolox equivalent antioxidant capacity (TEAC) was calculated from the equation determined from linear regression, after plotting known solutions of Trolox [13].…”

“…Thus, it is important to have a clear idea of the major phenolic families of which fruit and vegetables are comprised and the levels contained therein [10]. Several studies have been made for the determination of the antioxidant activity (AA) and total phenolic content (TPC) of date from different geographical places and varieties [11][12][13][14]. The date palm fruit possesses antioxidant and antimutagenic properties in vitro [15], therefore the AA and TPC of wide variety from Iranian date have been analyzed.…”

Pomegranate and mint syrup addition to green tea beverage stabilized its polyphenolic content and biofunctional potentials during refrigerated storage

“…This finding was in agreement with a previous report of Dhaouadi et al (2013). In previous reports, the use of aqueous-acetone (3/7, v/v) solvent was shown to provide a good extraction of the main polyphenols from different foods, including fruits, leaves, juices and syrups (Fattouch et al 2007;Dhaouadi et al 2011). This simple procedure lead to high yields of phenolics (Menelaos et al 2004) and removed interfering compounds, particularly cold acetone (−20°C) precipitates proteins and peptides, which absorb at 280 nm and interfere with polyphenols in HPLC analysis.…”

“…Methanol/water gradient was used according to the following solvent program: starting from 95 % A (0.5 % formic acid in Milli-Q water)and 5 % B(methanol), reaching 75 % A at 10 min, 65 % A at 30 min, 55 % A at 35 min, 55 % A at 40 min, 50 % A at 45 min, 45 % A at 50 min, 30 % A at 53 min, 25 % A at 56 min, and 20 % A at 60 min, followed by a post-time isocratic plateau for 10 min at 95 % A before the next injection. Extracts were analyzed using a modified version of the method described by Dhaouadi et al (2011). Mass spectrometry operating conditions were optimized in order to achieve maximum sensitivity values.…”