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

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

Polyphenolic Extract of Barbary-Fig (Opuntia ficus-indica) Syrup: RP–HPLC–ESI–MS Analysis and Determination of Antioxidant, Antimicrobial and Cancer-Cells Cytotoxic Potentials

The traditionally derived syrup of Opuntia ficus-indica fruit is commonly used in homemade confectionery. Herein, the aqueous-acetone extract prepared from the Tunisian O. ficus-indica syrup was investigated. The qualitatively and quantitatively polyphenolic content was analysed using reversed-phase high-performance liquid chromatography–diode array detection (RP-HPLC–DAD) coupled to electrospray ionisation–mass spectrometry (ESI–MS). The extract contained 19.95 ± 2.01 mg phenolics per gram of fresh starting material with isorhamnetin 3-O-robinobioside as the major compound (22.76%). The syrup extract showed strong antioxidant potentials as assessed by both ABTS and DPPH functional methods. It exhibited effective antimicrobial activity, particularly against Staphylococcus aureus and Staphylococcus epidermidis with a minimal bactericide concentration (MBC) of 1.3 mg phenolics/ml. Furthermore, at final concentrations in the range of 41.38–186.25 μg polyphenols/ml, the extract decreased human SH-SY5Y neuroblastoma and 3T3 fibroblast in vitro cell viability in a dose- and time-dependent manner compared to non-treated control cells. The observed effects were significantly (P < 0.05) high against cancer lines. Extract concentrations higher than 106.43 μg/ml reduced cancer cells viability to 50–60% 1–3 h post-treatment. Further in vivo insight studies should emphasise and validate the herein obtained results

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

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

Tea decoctions prevent body weight gain in rats fed high-fat diet; black tea being more efficient than green tea

Background/Aims: In contrast to the usual tea infusion, the anti-obesity effect of tea decoction (TD) is poorly documented. Here, we compared and contrasted the chronic effect of short-time decoction (15-min) of green versus black tea (GTD, BTD) prepared at a dose of 5% on lipid digestion and weight gain in rats fed high-fat diet (HFD) for 10 weeks. Methods: The rats were assigned into three groups (n = 10–12 each) and given ad libitum the HFD + water (CTRL) or GTD (GTGr) or BTD (BTGr). The food and fluid intake were measured daily and weight gains once/week. The fecal matters were collected twice/week for TPC, caffeine, total lipids and triglycerides (TG) analysis. In addition, the liver, perirenal and epididymal adipose tissues (AT) were removed and blood was collected for the same analysis and leptine level. Results: 10-weeks TD consumption increased fecal TG excretion (+170 in GTGr and +230% in BTGr; P < 0.001 vs CTRL). It reduced liver TG by 25 and 35% (P < 0.001 vs CTRL) and plasma TG by 36.6 and 48% (P < 0.01 vs CTRL) in GTGr and BTGr, respectively. The AT gains were reduced by 26.5 and 56.4% in GTGr and 60% in BTGr (P < 0.001 vs CTRL). The reduced AT was consistent with a reduction of 27 and 59% of leptin levels (P < 0.001 vs CTRL) and 21 and 55% of weight gains in GTGr and BTGr (P < 0.01 vs CTRL), respectively. Conclusion: Chronic GTD and BTD prevent fat storage in the liver, lowering blood lipids and glucose, increasing fecal excretion of TG, decreasing AT and weight gains in rats fed HFD, with a strong effect of BTD compared to GTD. Therefore, these beverages containing high amounts of TPC and caffeine could constitute a natural alternative in the prevention of obesity

Protective effects of azarole polyphenolic extracts against oxidative damage using in vitro biomolecular and cellular models

The antioxidant activity of the different polyphenolic extracts prepared from Tunisian azarole, Crataegus azarolus and Crataegus monogyna (Rosaceae family) leaves, fruit peel, pulp and syrup was evaluated using cholesterol, liposome and rat liver-homogenate oxidation assays and cytotoxic activity in differentiated Caco-2, undifferentiated Caco-2, and B16F10 melanoma cells. Protective effects were observed against thermal-cholesterol degradation at 140 °C for 1 h, which depended on the concentration and the type of the extract. Moreover, the pre-treatment with the phenolic extracts preserved liposomes and rat liver-homogenate from oxidative induced damage by Cu2+ and Fe2+ at 37 °C for 24 h and 2 h, respectively. Azarole phenolics inhibited the oxidation of polyunsaturated fatty acids (PUFA) and limited the production of oxidized compounds. Furthermore, within tested concentrations (0.24-4.8 mg/mL), all extracts did not show any toxic effect on differentiated Caco-2 cells; while, they were found cytotoxic to cancer Caco-2 cells, except, extracts of pulp and syrup of C. monogyna. Using B16F10 melanoma cell model, only azarole pulp and syrup extracts were found toxic and induced the production of melanin in a dose-dependent manne