Browsing by Author "Nogueira, Jose M. F."
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- Euphorbia denticulata Lam.: a promising source of phyto-pharmaceuticals for the development of novel functional formulationsPublication . Zengin, Gokhan; Uysal, Ahmet; Aktumsek, Abdurrahman; Mocan, Andrei; Mollica, Adriano; Locatelli, Marcello; Custódio, Luísa; Neng, Nuno R.; Nogueira, Jose M. F.; Aumeeruddy-Elalfi, Zaahira; Mahomoodally, M. FawziIn this study, Methanolic extracts of Euphorbia denticulata parts (flowers, leaf, stem, and mix of aerial parts) were assessed for a panoply of bioactivities. Inhibitory potential against key enzymes involved in diabetes (alpha-glucosidase and alpha-amylase), obesity (pancreatic lipase), neurodegenerative diseases (cholinesterases), and hyperpigmentation (tyrosinase) was evaluated. The antioxidant and antibacterial properties were also assessed. The total phenolic, flavonoid, and phytochemical profile were established using HPLC/DAD and molecular modelling studies on specific target compounds were performed in silico. The flower extract was found to be rich in phenolics and flavonoids, (60.11 +/- 1.40 mgGAE/g and 42.04 +/- 0.16 mgRE/g respectively), which tend to correlate with the high radical scavenging activity of this extract (120.34 +/- 3.33 mgTE/g and 165.42 +/- 2.16 mgTE/g for DPPH and ABTS respectively). Catechin, epicatechin, gallic acid, p-OH-Benzoic acid, rosmarinic acid, and epigallocatechin gallate, found in significant abundance in the extracts were assessed using molecular modelling with the aim to study their docking properties on a set of six enzymes used in this study. The extracts were moderately effective with MIC values ranging between 1.56 to 6.25 mg/ml, but potent growth inhibitors of MRSA strains. Results amassed herein can be used as a stimulus for further studies geared towards the development of novel phyto-pharmaceuticals. (C) 2016 Elsevier Masson SAS. All rights reserved.
- Exploring Caralluma europaea (Guss.) NEBr. as a potential source of bioactive molecules: In vitro antioxidant and antidiabetic properties, and phenolic profile of crude extracts and fractionsPublication . Dra, Loubna Ait; Rodrigues, Maria Joao; Neng, Nuno da Rosa; Nogueira, Jose M. F.; Elamine, Youssef; Aghraz, Abdellah; Markouk, Mohamed; Larhsini, Mustapha; Custódio, LuísaCaralluma europaea (Guss.) N.E.Br is a succulent medicinal species used in the Moroccan traditional medicine for its anticancer and antidiabetic properties. In this work, this species was explored for the in vitro antidiabetic and antioxidant properties of crude methanol and dichloromethane extracts, and obtained fractions, from its aerial organs. In vitro antidiabetic properties were evaluated towards baker's yeast and rat's intestinal alpha-glucosidase, and alpha-amylase. Four in vitro methods were used to appraise the antioxidant potential, namely radical scavenging activity (RSA) on 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), and iron and copper chelating assays. Finally, the profile of the main phenolic compounds present in the samples was assessed by high-performance liquid chromatography equipped with diodearray detection (HPLC-DAD). The highest inhibition of baker's yeast alpha-glucosidase was obtained with the methanol extract (87%), and its fractions, with a maximum inhibition of 83% at the concentration of 10 mg/ml. The most significant inhibition of mammalian alpha-glucosidase was obtained with the dichloromethane crude extract (85%), and corresponding fractions at 10 mg/ml. Moderate activity was achieved with the two extracts against a-amylase (52-53%) at 10 mg/ml, but no relevant activity was detected for most fractions. Crude extracts had a significant RSA against DPPH and ABTS, with range values of 83-98% (methanol extracts) and 53-80% (dichloromethane extracts). Fractions from the methanol extract were more active against tested radicals. Crude extracts had chelating activity on both metals, and the highest copper chelation was achieved with the methanol extract, while the dichloromethane extract and the majority of fractions from both extracts presented the highest iron chelation at 10 mg/ml. A total of 21 phenolic compounds were identified and quantified by HPLC-DAD in the samples, and the main compounds detected were catechine hydrate and salicylic and caffeic acids. Our results suggest that C. europaea extracts contain compounds with in vitro antioxidant and antidiabetic properties with potential applications in the pharmaceutical and food industries.
- Unlocking the in vitroanti- inflammatory and antidiabetic potential of Polygonum maritimumPublication . Rodrigues, Maria Joao; Custodio, Luisa; Lopes, Andreia; Oliveira, Marta; Neng, Nuno R.; Nogueira, Jose M. F.; Martins, Alice; Rauter, Amelia P.; Varela, Joao; Barreira, L.Context: Several Polygonum species (Polygonaceae) are used in traditional medicine in Asia, Europe and Africa to treat inflammation and diabetes. Objective: Evaluate the in vitro antioxidant, anti-inflammatory and antidiabetic potential of methanol and dichloromethane extracts of leaves and roots of the halophyte Polygonum maritimum L. Material and methods: Antioxidant activity was determined (up to 1mg/mL) as radical-scavenging activity (RSA) of 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), copper (CCA) and iron (ICA) chelating activities and iron reducing power (FRAP). NO production was measured in lipopolysaccharide (LPS)-stimulated macrophages for 24 h at concentrations up to 100 mu g/mL and antidiabetic potential was assessed by alpha-amylase and alpha-glucosidase inhibition (up to 10 g/mL) assays. The phytochemical composition of the extracts was determined by gas chromatography-mass spectrometry (GC-MS). Results: The methanol leaf extract had the highest activity against DPPH center dot (IC50 = 26 mu g/mL) and ABTS1(+)center dot (IC50 = 140 mu g FRAP (IC50 = 48 mu g/mL) and CCA (IC50 = 770 mu g/mL). Only the dichloromethane leaf extract (LDCM) showed anti-inflammatory activity (IC50 = 48 mu g/mL). The methanol root (IC50 = 19 mu g/mL) and leaf (IC50 = 29 mu g/mL) extracts strongly inhibited baker's yeast alpha-glucosidase, but LDCM had higher rat's alpha-glucosidase inhibition (IC50 = 2527 mu g/mL) than acarbose (IC50 = 4638 mu g/mL). GC-MS analysis identified beta-sitosterol, stigmasterol, 1-octacosanol and linolenic acid as possible molecules responsible for the observed bioactivities. Conclusions: Our findings suggest P. maritimum as a source of high-value health promoting commodities for alleviating symptoms associated with oxidative and inflammatory diseases, including diabetes.