Algarve Centre for Marine Sciences

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Antioxidant activity and enzyme inhibitory potential of Euphorbia resinifera and E. officinarum honeys from Morocco and plant aqueous extracts

Publication . Boutoub, Oumaima; El-Guendouz, Soukaïna; Estevinho, Leticia M.; Paula, Vanessa B.; Aazza, Smail; El Ghadraoui, Lahsen; Rodrigues, Brígida; Raposo, Sara; Carlier, Jorge D.; Costa, Maria Clara; Miguel, Maria da Graça

Natural products may be applied in a wide range of domains, from agriculture to food and pharmaceutical industries. In this study, the antioxidant properties and the capacity to inhibit some enzymatic activities of Euphorbia resinifera and Euphorbia officinarum aqueous extracts and honeys were assessed. The physicochemical characteristics were also evaluated. Higher amounts of iron, copper and aluminium were detected in E. officinarum honey, which may indicate environmental pollution around the beehives or inadequate storage of honey samples. This honey sample showed higher amounts of total phenols and better capacity for scavenging superoxide anion free radicals and DPPH free radicals as compared with E. resinifera honey, but poorer capacity for inhibiting lipoxygenase, acetylcholinesterase, tyrosinase and xanthine oxidase. The ratio plant mass:solvent volume (1:100) and extraction time (1 - 2 h) were associated with higher total phenols and better antioxidant activities and lipoxygenase, acetylcholinesterase and tyrosinase inhibitory activities, regardless of the plant species. The aqueous extracts had systematically higher in vitro activities than the respective honey samples.

2021Journal article

Open access

Chemical Characterization and Biological Properties Assessment of Euphorbia resinifera and Euphorbia officinarum Moroccan Propolis

Publication . Boutoub, Oumaima; El-Guendouz, Soukaïna; Matos, Isabel; El Ghadraoui, Lahsen; Costa, Maria Clara; Carlier, Jorge D.; Faleiro, Maria Leonor; Figueiredo, Ana Cristina; Estevinho, Leticia M.; Miguel, Maria Graça

Although the plants of the genus Euphorbia are largely exploited by therapists in Morocco, the composition and antibacterial activities of propolis from these plants are still unknown. To address this gap, this study aimed to characterize the pollen type, the volatile compounds, and the phenolic and mineral profiles of three Euphorbia propolis samples collected in Morocco and evaluate their antimicrobial activities. The minimum inhibitory concentration of the propolis samples was determined by the microdilution method, and the anti-adherence activity was evaluated by the crystal violet assay. The examination of anti-quorum-sensing proprieties was performed using the biosensor Chromobacterium violaceum CV026. Pollen analysis revealed that Euphorbia resinifera pollen dominated in the P1 sample (58%), while E. officinarum pollen dominated in the P2 and P3 samples (44%). The volatile compounds were primarily composed of monoterpene hydrocarbons, constituting 35% in P1 and 31% in P2, with alpha-pinene being the major component in both cases, at 16% in P1 and 15% in P2. Calcium (Ca) was the predominant mineral element in both E. resinifera (P1) and E. officinarum (P2 and P3) propolis samples. Higher levels of phenols, flavonoids and dihydroflavonoids were detected in the E. officinarum P2 sample. The minimum inhibitory concentration (MIC) value ranged from 50 to 450 mu L/mL against Gram-positive and Gram-negative bacteria. Euphorbia propolis displayed the ability to inhibit quorum sensing in the biosensor C. violaceum CV026 and disrupted bacterial biofilm formation, including that of resistant bacterial pathogens. In summary, the current study evidences the potential use of E. officinarum propolis (P2 and P3) to combat important features of resistant pathogenic bacteria, such as quorum sensing and biofilm formation.

2024Journal article

Open access

Persistence of antioxidant properties of Carpobrotus edulis L. extract after in vitro digestion

Publication . Oliveira, Daniela; Dias, Maria Inês; Barros, Lillian; Custódio, Luísa; Oliveira, Rui

The human being is unknowingly cxposcd to many toxic chcrnicals through diet, which can trigger an excessive pra ductian a f reactive oxygen and ni trogen species that can cause a redax imbalance and generate oxidativc stress in thc gastrointcstin al tract, potcntially contri buting to the development of degenerative discases. In fact, oxidative stress has becn indi cated to contribute to ali three phases a f carcinogenesis. Thus, the attenuation of oxidative strcss could contribute to the prevention of cancer in itiation. Halophytes are associated wi th strong ant ioxidant capacity, which makes them excellent candidates to anen uale lhe oxidative stress in the gaslrointestinal tracl. For instance, Carpobrotus edulis L is an edible halophyte 1hal has been reported for its antioxidant properties and high content in phenolic compounds. However, most of these stud ies did not consider the impact of digeslion, which can alter the chemical structure of the phytochemicals and possibly their biaacti vilics. To our knowledge, there are no studies considering the efTect of digestion on lhe antiox idant properti es of C. edulis. The objecti ve of th is work was to evaluate the impact of digestion on the chemical compos ition and ant ioxidant capacity of C. edulis aerial part ethanol extract (CEE). The extract was subjected to in vilro simulation of human digestion (IVO) and aI the end we obtained the digesled extracl lhat becomes avai lable in lhe colon (DCEE). Both forms of lhe extract were subjected to chemical characterization by lhe Folin-Ciocalteu melhod and by LC-DADESI/ MS· to delect alterations caused by IVO. The anti oxidant capacity ofCEE and DCEE was evaluated in vi/ro by determ in ati an of scavenging of ni lric oxide (NO) and 2,2-diphenyl- l picrylhydrazyl (DPPH) rad icaIs and in viab il ity assays again st hydrogen peroxide (H,O,) in the yeast Saccharomyces cerevisiae. The resu lts showed Ihat lhe phenolic composition ofCEE was severely affected by IVO. as wel! as the capacity to scavenge the OPPH radical In oppositian, the capac ity to scavenge the NO rad ical increased. Moreover, CEE protected yeast cel ls against 1-1,0" corroborating the antioxidant propert ies reported in the li leralure. These properties seem to pers isl after IVO, bUl at a lower extent. Thus, although the IVD s ignificantly altered the chemi cal compos it ion of CEE and decreased the antioxidant capacity, lhe beneficiai effect is still relevant since it provided pratect ion against oxidative stress in the viabi lity assay in S. cerevisiae. Thercforc. C. edlllis scems to have potent ia l to be included in the human diet to decrease the oxidative stress generated in the gastrointestinal tract due to lhe recurrent consumption of contaminated foods and lhus could play a role in the prevention of carcinogenesis.

2022Conference object

Open access

Harnessing the bioactive potential of Limonium spathulatum (Desf.) kuntze: insights into enzyme inhibition and phytochemical profile

Publication . Youssef, Seria; Custódio, Luísa; Rodrigues, Maria João; Pereira, Catarina G.; Calhelha, Ricardo C.; Jekő, József; Cziáky, Zoltán; Ben Hamed, Karim

This study assessed the halophyte species Limonium spathulatum (Desf.) as a possible source of natural ingredients with the capacity to inhibit enzymes related to relevant human health disorders and food browning. Extracts using food-grade solvents such as water and ethanol were prepared by maceration from dried L. spathulatum leaves. They were evaluated for in vitro inhibition activity of enzymes such as acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), -glucosidase, tyrosinase and lipase, related to Alzheimer’s disease, type-2-diabetes mellitus, skin hyperpigmentation, and obesity, respectively. These extracts were also appraised for in vitro acute toxicity on tumoral and non-tumoral cell lines and their chemical composition by high-performance liquid chromatography coupled with electrospray ionization mass spectrometry (HPLC-ESI-MS/MS). The extracts were more effective towards BChE than AChE. The best results were obtained with the hydroethanolic and water extracts, with IC50 values of 0.03 mg/mL and 0.06 mg/mL, respectively. The hydroethanolic extract had the highest capacity to inhibit -glucosidase (IC50: 0.04 mg/mL), higher than the positive control used (acarbose, IC50 = 3.14 mg/mL). The ethanol extract displayed the best inhibitory activity against tyrosinase (IC50 = 0.34 mg/mL). The tested samples did not inhibit lipase and exhibited low to moderate cytotoxic activity against the tested cell lines. The hydroethanolic extract had a higher diversity of compounds, followed by the ethanol and water samples. Similar molecules were identified in all the extracts and were mainly hydroxybenzoic acids, hydroxycinnamic acids, and flavonoids. Taken together, these results suggest that L. spathulatum should be further explored as a source of bioactive ingredients for the food, cosmetic, and pharmaceutical industries.

2023Journal article

Open access

Comparative study of the antioxidant and enzyme inhibitory activities of two types of moroccan euphorbia entire honey and their phenolic extracts

Publication . Boutoub, Oumaima; El-Guendouz, Soukaïna; Manhita, Ana; Dias, Cristina Barrocas; Estevinho, Leticia M.; Paula, Vanessa B.; Carlier, Jorge D.; Costa, Maria Clara; Rodrigues, Brígida; Raposo, Sara; Aazza, Smail; El Ghadraoui, Lahsen; Miguel, Maria da Graça

Honey is a natural food product very famous for its health benefits for being an important source of antioxidant and phenolic compounds. Euphorbia honeys obtained from different regions of Morocco were evaluated for their ability to inhibit acetylcholinesterase, lipoxygenase, tyrosinase and xanthine oxidase activities. Their antioxidant properties were evaluated using the: 2,2-diphenyl- 1-picrylhydrazyl (DPPH) radical-scavenging capacity, nitric oxide scavenging activity (NO) and scavenging ability of superoxide anion radical. Then, the phenolic extracts of the same entire honey samples were evaluated by liquid chromatography coupled to diode array detection and mass spectrometry (LC-DAD-MS) and tested for the biological activities previously evaluated on the entire honeys, in order to conduct a comparative study between both (honey and phenolic extracts). The chromatographic profiles for the studied Euphorbia honey extracts were different. Phenolic compounds gallic acid, 4-hydroxybenzoic acid and p-coumaric acid were detected in all samples, whereas kampferol was only present in two samples. Physicochemical parameters and total phenolic content were also determined. Entire honey that recorded the highest rate of phenols was sample M6 (E. resinifera) = 69.25 mg GAE/100 g. On the other hand, the phenolic extracts had better antioxidant and enzyme inhibitory activities than the entire honeys, regardless the monofloral honey type. In conclusion, the studied Euphorbia honeys may have a great potential as antioxidant, anti-inflammatory and anti-tyrosinase sources for pharmaceutical and cosmetic applications.

2021Journal article

Open access