Percorrer por autor "Mnif, Wissem"
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- Aqueous extracts from tunisian diplotaxis: phenol content, antioxidant and anti-acetylcholinesterase activities, and impact of exposure to simulated gastrointestinal fluidsPublication . Bahloul, Nada; Bellili, Sana; AAZZA, Smail; Cherif, Ameur; Faleiro, Leonor; Antunes, Maria Dulce; Miguel, Maria Graça; Mnif, WissemAntioxidants have been considered essential for preventing cell damage by scavenging deleterious free radicals. The consumption of antioxidant-rich plants is associated with a reduced risk of some chronic diseases. This study evaluates the antioxidant and acetylcholinesterase inhibition activities of aqueous extracts obtained from different parts of Diplotaxis simplex and Diplotaxis harra from Tunisia. The study also aimed to investigate the action of simulated gastrointestinal juice on antioxidant activities of both extracts. The total phenolic, flavone and flavonol, and flavanone and dihydroflavonol contents were determined by Folin-Ciocalteau, aluminum chloride and 2,4-dinitrophenylhydrazine colorimetric methods, respectively. The metal ion chelating activity, acetylcholinesterase inhibition capacity, and free radical scavenging potential of the extracts towards ABTS (2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid), DPPH (2,2-diphenyl-1-picrylhydrazyl), hydroxyl, superoxide and nitric oxide were also evaluated. The action of simulated gastro-intestinal fluids on the flavone and flavonol content and total antioxidant activity of the flower extracts was surveyed. Extracts from the seeds and flowers of D. simplex and D. harra displayed the highest amounts of phenols (2691.7 and 2694.5 mg Caffeic Acid Equivalent (CAE)/100 mg; 3433.4 and 2647.2 mg CAE/100 mg, respectively) and flavonols/flavones (2144.4 and 2061.1 mg Rutin Equivalent (RE)/100 g; 1922.6 and 1461.1 mg RE/100 g, respectively). The flower and seed extracts exhibited the highest rates of antioxidant and acetylcholinesterase inhibition activities. A decrease in the flavonoid content and antioxidant activity was observed after extract exposure to simulated saliva. Antioxidant and acetylcholinesterase inhibition activities were noted to depend on plant species and plant parts. In vitro gastrointestinal digestion is useful in assessing the bio-accessibility of compounds with biological activities from food. The simulated gastrointestinal fluids influenced the flavonoid concentration and antioxidant activity.
- A brief review on new naturally occurring cembranoid diterpene derivatives from the soft corals of the genera Sarcophyton, Sinularia, and Lobophytum since 2016Publication . Rodrigues, Inna; Miguel, Maria; Mnif, WissemThis work reviews the new isolated cembranoid derivatives from species of the genera Sarcophyton, Sinularia, and Lobophytum as well as their biological properties, during 2016⁻2018. The compilation permitted to conclude that much more new cembranoid diterpenes were found in the soft corals of the genus Sarcophyton than in those belonging to the genera Lobophytum or Sinularia. Beyond the chemical composition, the biological properties were also reviewed, namely anti-microbial against several Gram-positive and Gram-negative bacteria and fungi, anti-inflammatory and anti-tumoral against several types of cancer cells. In spite of the biological activities detected in almost all samples, there is a remarkable diversity in the results which may be attributed to the chemical variability that needs to be deepened in order to develop new molecules with potential application in medicine.
- In-vitro antioxidant and anti-inflamatory activities of Pituranthos chloranthus and Artemisia vulgaris from TunisiaPublication . Ben Nasr, Soumeya; AAZZA, Smail; Mnif, Wissem; Miguel, MariaPituranthos chloranthus and Artemisia vulgaris L. are two of the most important aromatic and medicinal species from the Apiaceae and Asteraceae families, respectively. They are traditionally used in certain pathologies in which inflammatory processes are involved. The present study investigates the potential of aqueous extracts of Tunisian P. chloranthus and A. vulgaris as a natural alternative source of antioxidant and anti-inflammatory activities using in-vitro techniques. The antioxidant activities of aqueous extracts were evaluated through several assays: capacity for scavenging free radicals (ABTS, DPPH, hydroxyl, superoxide, nitric oxide); and total antioxidant capacity by ferric reducing power activity and inhibition of lipid peroxidation by thiobarbituric acid reactive species (TBARS) method. The anti-inflammatory activity was evaluated through the lipoxygenase (LOX) inhibitory activity. P. chloranthos aqueous extract presented higher concentration of total phenols than A. vulgaris extract, nevertheless higher capacity for scavenging ABTS, superoxide, hydroxyl. and NO free radicals. In the presence of liver homogenate, both extracts had poorer antioxidant activity than in the remaining lipid substrates. P. chloranthos extract had a higher ability for inhibiting lipoxygenase twice higher than A. vulgaris, while it had lower capacity for reducing Fe3+ than P. chloranthos extract. Our results suggest that there are differences of antioxidant activity between both samples, but also the strength for inhibiting the oxidation is highly dependent on the method used.