Anti- and Pro-Oxidant Activity of Polyphenols Extracts of Syrah and Chardonnay Grapevine Pomaces on Melanoma Cancer Cells.

The phenolic composition of Syrah and Chardonnay grape pomaces was studied to assess their antioxidant and prooxidant properties. Polyphenols were extracted by a "green" hydroalcoholic solvent (ethanol/water 1:1 v/v), and a detailed chemical and electrochemical characterization of the phenolic compounds was performed. The antioxidant and prooxidant capacity of the pomace was first studied by cyclic voltammetry (CV) and other reference analytical assays, then with biological tests on B16F10 metastatic melanoma cancer cells. Electrochemical data showed that, when a +0.5 V potential was applied, a low to moderate antioxidant capacity was observed. MTT test showed an increasing viability of melanoma cells, after treatments at low concentration (up to 100 µg/mL) and for a short time (6 h), but when cells were treated with higher doses of extract (≥250 µg/mL for 12/24 h), their viability decreased from 25 to 50% vs. control, depending on treatment time, dose, and extract origin. A stronger prooxidant activity resulted when 250 µg/mL of extract was combined with non-toxic doses of H2O2; this activity was correlated with the presence of copper in the extracts. This study shows the potential of winemaking by-products and suggests the opportunity to exploit them for the production of cosmeceuticals, or for combined therapies with approved anticancer drugs.

The Molecular Characterization and Biological Assessment of the Leaves Extracts of Loofah Reveal their Nutraceutical Potential.

BACKGROUND: Luffa cylindrica is a plant that is widely distributed in Africa and Asia and can be grown in regions with tropical or subtropical climates. Few patents dealt with Loofah biological properties, including some functional foods formulated from its leaves. OBJECTIVE: This study aimed to structurally and functionally characterize the bioactive compounds of L. cylindrica leaves grown in two different environments. METHODS: The extracts of L. cylindrica leaves collected from two Tunisian locations: Essouasi (LE), a semi-arid region and Medenine (LM), an arid region, were investigated for their phenolic compounds and fatty acids using HPLC/TOF-MS and GC-MS techniques, respectively. Furthermore, the antioxidant capacity was evaluated with DPPH, Chelating effect, Hydroxyl radical and Superoxide anion scavenging activities while the anticancer activity against HeLa cell lines was assessed using xCELLigence real time cell analyzer and lactate dehydrogenase cytotoxicity assay. RESULTS: The antiproliferative capacity of both extracts was time and dose-dependent, with LE presenting the lowest HeLa cell index (CI = 0.035 ± 0.018, 250 µg/ml). LE also showed the best cytotoxic capacity (56.49 ± 0.8%) and antioxidant potential (IC50 = 54.41 ± 1.12 µg/ml for DPPH and 12.12 ± 0.07 µg/ml for chelating effect). 14 phenolic compounds were detected in LE, with ferulic acid being the major compound (5128.5 ± 4.09 µg Phenols/g), while LM had only 6 phenolics. GCMS analysis showed the presence of omega-3 fatty acids in LE. CONCLUSIONS: Our findings suggest that L. cylindrica leaves, especially when collected from semiarid regions, are promising for formulating nutraceuticals of interest.

Phytochemical profile and insecticidal activity of Agave americana leaf extract towards Sitophilus oryzae (L.) (Coleoptera: Curculionidae).

The main objective of the present study is to introduce a new and ecologically safe method for managing the rice weevil, Sitophilus oryzae. Therefore, the Agave americana leaf extract's phytochemical profile, and its insecticidal activity against the adults of S. oryzae were evaluated. The A. americana leaf extract was screened for the following phytochemicals: total phenolics (14.70 ± 0.31 mg GAE/g FW), total flavonoids (5.15 ± 0.18 mg RE/g FW) and saponins (10.32 ± 0.20 mg OAE/g FW). The HPLC-ESI/TOF-MS analysis results revealed that flavonoid glycosides (kaempferol, quercetin, and isorhamnetin derivates) were the major phenolic compounds of the A. americana leaf extract. In addition, the GC-MS analysis identified n-alkanes (77.77%) as significant compounds of the lipophilic fraction from the leaf extract. Moreover, the insecticidal potential was assessed through contact and repellent bioassays towards the rice weevil adults. The LD50, LC50, and RC50 values were 10.55 µg/insect, 8.99 µg/cm2, and 0.055 µg/cm2 for topical application method, treated filter-paper method, and repellent bioassay, respectively. Furthermore, the A. americana leaf extract inhibited digestive enzyme activities, and median inhibition concentrations IC50 were evaluated to be 146.06 ± 1.74 and 86.18 ± 1.08 µg/mL for α-amylase and protease, respectively. Overall, our results highlighted the promising potential of the leaf extract against S. oryzae adults, allowing us to recommend the extract under investigation as an ecofriendly alternative to synthetic insecticides.

Variations in the Bioactive Compounds Composition and Biological Activities of Loofah (Luffa cylindrica) Fruits in Relation to Maturation Stages.

The present work aimed to determine the antioxidant and antiproliferative potential of Luffa cylindrica fruits collected at two different maturation stages and to identify and compare their functional components composition. The MeOH extracts of L. cylindrica fruits harvested at 60 - 65 days after seeding (S1) and 85 - 90 days after seeding (S2) were investigated for their antioxidant activity using various assays. Furthermore, the antiproliferative activity of the extracts against HeLa human cervical cancer cells was explored with xCELLigence real time cell analyzer, while the effect of the samples on the membrane integrity of the same cell line was assessed using LDH cytotoxicity leakage assay. Ultimately, the phytochemicals were analyzed using GC/MS and HPLC/TOF-MS. The S1 sample had higher contents and more diversity in the phenolic compounds composition than S2. Furthermore, the S1 extract showed the highest antioxidant and antiproliferative activity, while the S2 extract had higher cytotoxicity towards HeLa cells. The findings revealed that the time of harvest has a big impact on the phytochemicals content and activity and that harvesting L. cylindrica at an early stage before the beginning of the development of the cellulose fibrous system is recommended for a rich phytochemical composition and efficient antioxidant and antiproliferative activities.

Bioactive compounds contents, antioxidant and antimicrobial activities during ripening of Prunus persica L. varieties from the North West of Tunisia.

Bioactive molecules from fruits of four varieties of Prunus persica at different stages of ripening (green, small orange, red) were studied. For example, contents on polyphenols (20.36mg GAE/g FW) and flavonoids (0.764mg RE/g FW) were high and varied according variety. The antioxidant activity, using four different tests (DPPH radical scavenging activity, reducing power, ß carotene bleaching system and TBARS assay) showed that the variety Chatos exhibited the highest antioxidant activity comparing with others varieties. The antibacterial activity of Prunus persica varieties studied seems to be more sensitive against Staphylococcus aureus and Listeria monocytogenes. The capacity of peach DMSO extracts to inhibit Candida albicans growth was more pronounced, especially, in the presence of Chatos DMSO extract. Enzymes inhibition gives results which correlate with polyphenols, flavonoids and condensed tannins contents, and so, confirm the fascinating bioactivity of this fruit.

Protective effect of the octadecaneuropeptide on hydrogen peroxide-induced oxidative stress and cell death in cultured rat astrocytes.

Oxidative stress, resulting from accumulation of reactive oxygen species (ROS), plays a critical role on astrocyte death associated with neurodegenerative diseases. Astroglial cells produce endozepines, a family of biologically active peptides that have been implicated in cell protection. Thus, the purpose of the present study was to investigate the potential protective effect of one of the endozepines, the octadecaneuropeptide ODN, on hydrogen peroxide (H(2) O(2) )-induced oxidative stress and cell death in rat astrocytes. Incubation of cultured astrocytes with graded concentrations of H(2) O(2) for 1 h provoked a dose-dependent reduction of the number of living cells as evaluated by lactate dehydrogenase assay. The cytotoxic effect of H(2) O(2) was associated with morphological modifications that were characteristic of apoptotic cell death. H(2) O(2) -treated cells exhibited high level of ROS associated with a reduction of both superoxide dismutases (SOD) and catalase activities. Pre-treatment of astrocytes with low concentrations of ODN dose-dependently prevented cell death induced by H(2) O(2) . This effect was accompanied by a marked attenuation of ROS accumulation, reduction of mitochondrial membrane potential and activation of caspase 3 activity. ODN stimulated SOD and catalase activities in a concentration-dependent manner, and blocked H(2) O(2) -evoked inhibition of SOD and catalase activities. Blockers of SOD and catalase suppressed the effect of ODN on cell survival. Taken together, these data demonstrate for the first time that ODN is a potent protective agent that prevents oxidative stress-induced apoptotic cell death.