Browsing by Author "Garcia, Pablo A."
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- Chemical characterization and bioactive properties of two aromatic plants: Calendula officinalis L. (flowers) and Mentha cervina L. (leaves)Publication . Miguel, Maria da Graça; Barros, Lillian; Pereira, Carla; Calhelha, Ricardo C.; Garcia, Pablo A.; Castro, María Ángeles; Santos-Buelga, Celestino; Ferreira, Isabel C.F.R.The chemical composition and bioactive properties of two plants (Calendula officinalis L. and Mentha cervina L.) were studied. Their nutritional value revealed a high content of carbohydrates and low fat levels, and very similar energy values. However, they presented different profiles in phenolic compounds and fatty acids; C. officinalis presented mainly glycosylated flavonols and saturated fatty acids, while M. cervina presented mainly caffeoyl derivatives and polyunsaturated fatty acids. M. cervina showed the highest concentration of phenolic compounds while C. officinalis presented higher amounts of sugars, organic acids and tocopherols. The highest antioxidant and cytotoxic activities were obtained for the hydromethanolic extract of M. cervina, which presented the lowest values of EC50 and exhibited cytotoxicity against the four tumor cell lines tested. Infusions showed no cytotoxicity for the tumor cell lines, and none of the extracts showed toxicity against non-tumor cells. This study contributes to expand the knowledge on both natural sources and therefore their use.
- Cytinus hypocistis L. plant as source of phenolic compounds with anti-lipid peroxidation activityPublication . Silva, Ana Rita; Dias, Maria Inês; Garcia, Pablo A.; Barros, Lillian; Ferreira, Isabel C.F.R.After a period in which synthetic compounds were preferred, there is an increasing interest m studyüig the bioactive properties of plants and the active principies behind their therapeutic properties [l]. Polyphenols are the largest and the most widespread group of secondary metabolites in plants. With a great variety of structures, ranging from simple compounds with few aromatic rings, such as phenolic acids, to highly polymeric substances, such as tannins; they are commonly found in both edible and inedible plants, and have been reported to have multiple biological effects, including antioxidant activity [2]. Cytinus hypocistis L. is an endophytic parasitic plant occurring in the Mediterranean region and it was used in a wide variety of traditional healthcare practices, induding dysentery, tumour of the throat and eye inflammation treatment [3]. Despite these wealthy traditional uses, its chemical composiüon is largely unknown. Therefore, the aim of this study was to characterize this plant in terms of polyphenolic composition and capacity to inhibit lipid peroxidation. Plant specimens were coUected in June 2018 in Castro Daire, Portugal. After lyophilisation, the phenolic compounds were analysed in four diíFerent hydroethanolic extracts ofC. hypocistis (whole plant, nectar chamber of thef lower,p etals, ands talks) usinga nH PLC-DAD/ESI-MSs ystem. Seventeenp henolic compounds were identified, sbcteen hydrolyzable tannins (with trigalloyl-diHHDPglucoside as the major compound) and one flavan-3-ol ((+)-catechin), being the petals the sample that presented the highest concentration ofthe identified compounds. TBARS method was used to evaluate the inhibition of lipid peroxidation, a widely recognized primary toxicological event caused by the generation offree radicais [4]. In this study, the hydroethanolic extracts ofthe four samples were capable ofpreventing the formation ofmalondialdehyde (MDA), a secondary product oflipid peroxidation, in a dose dependent manner. The highest anti-lipid peroxidation activitywas revealed by the petals extract (342 ng/mL), also exhibiting the highest concentration ofphenolic compounds. This activity is much better than the one displayed by the standard Trolox. This study revealed that the extracts might preveni reactive radical species from damaging biomolecules such as lipids in the cells. These features are behind the health benefits for humans and the wide use of tannin-containing plant extracts in herbal medicine [5]. A correlation study will also be performed to understand the influence ofphenolic compounds in the bioactive properties ofthis plant.
- Extraction of Bioactive Compounds from Rubus Idaeus Bioresidues: A Full Screening on Phenolic Composition and Bioactive PotentialPublication . Plasencia, Paula; Finimundy, Tiane C.; Carocho, Márcio; Calhelha, Ricardo C.; Añibarro-Ortega, Mikel; Pires, Tânia C.S.P.; Barreiro, Filomena; Garcia, Pablo A.; Barros, Lillian; Heleno, Sandrina A.Purpose Rubus idaeus cultivation has boosted productivity due to its high nutritional value. In consequence, waste produc- tion increased. The discarded biomass, including leaves and aerial components, can be transformed into valuable functional ingredients for industrial applications, such as cosmetics. Studying their bioactivity potential is highly relevant. Methods According to the present idea, the research involved producing extracts from raspberry plant branches and leaves by employing four different techniques: aqueous decoction, aqueous infusion, hydroethanolic maceration, and ultrasound- assisted extraction (UAE). Subsequently, these compounds were screened for their bioactive potential, including antioxidant, antibacterial, anti-inflammatory, and cytotoxic properties. Results The ultrasound-assisted extraction produced extracts rich in phenolic compounds, whereas the infusion and macera- tion methods resulted in higher flavonol contents. Among the identified phenolic compounds, hydrolyzable tannins, particu- larly galloyl-bis-HHDP-glucose, were the most dominant ones. Regarding antioxidant potential, the decoction extract was the strongest, while the infusion showed the greatest potential for inhibiting lipid peroxidation. The UAE extract was found to be highly effective as an antibacterial agent. Both infusion and UAE extracts demonstrated the highest anti-inflammatory potential. Conclusion The combination of these results highlights the sample’s bioactive potential and the importance of exploiting bioresidues as unique, sustainable candidates for industrial applications.
- Optimizing ultrasound-assisted extraction for enhanced yield of bioactive compounds from Vaccinum myrtillus and Rubus idaeus bioresiduesPublication . Plasencia, Paula; Carocho, Márcio; Finimundy, Tiane C.; Calhelha, Ricardo C.; Molina, Adriana K.; Pires, Tânia C.S.P.; Barreiro, Filomena; Garcia, Pablo A.; Barros, LillianDue to the high nutritional value of berries, their extensive production has led to the accumulation of bioresidues. To leverage these residues, the distinct chemical composition, and functional properties of the leaves and other aerial parts can be used to produce high-value ingredients for cosmetics. Ultrasound-assisted extraction (UAE) is considered simple, fast, efficient, and more affordable than other techniques for obtaining bioactive extracts. This study aimed to determine the optimal conditions for maximizing ultrasound-assisted extraction yields from raspberry (RB) and blueberry (BB) pruning using response surface methodology (RSM). Three factors were analyzed: the ethanol-to-water solvent ratio (ranging from 0 % to 100 % ethanol), extraction time (ranging from 5 to 30 min), and extraction power (ranging from 20 % to 100 %, with a maximum ultrasound power of 500 W). The Box-Behnken design included 17 individual randomized runs to optimize the extract's dry weight range from 22.2 to 202.8 mg/g for RB and 123.5-394.0 mg/g for BB. The optimal extraction point for RB was at 40 % ethanol-to-water ratio, 16 min, and 98 % extraction power, while for BB, it was at 59 % ethanol in water, 30 min, and 73 % extraction power. Higher levels of hydrolyzable tannins characterized the optimal point of RB, while BB showed greater contents of flavonoids. Both revealed strong antioxidant and antibacterial activities, with RB showing higher antioxidant activity than Trolox. These results suggest that the extracts from pruning are obtained at interesting compositions and yields, offering advantages to use in the cosmetic industry due to their bioactivity.
- Recovery of high valuable bioactive molecules from Vaccinium myrtillus L. bioresiduesPublication . Plasencia, Paula; Heleno, Sandrina A.; Finimundy, Tiane C.; Carocho, Márcio; Calhelha, Ricardo C.; Añibarro-Ortega, Mikel; Alves, Maria José; Oludemi, Taofiq; Quidiongo, Nuno; Barreiro, Filomena; Garcia, Pablo A.; Ferreira, Isabel C.F.R.; Barros, LillianPurpose The interest in using bioresidues produced by the agri-food industry is increasingly intrinsic to the world economy. As such, researchers started to look for new ways to enhance its use, developing innovations to transform these residues into high-value raw materials with industrial application, promoting the circular economy concept. Methods Therefore, pruning residues from the production of Vaccinium myrtillus L. could be an interesting exploitation feld, given its position as a superfood due to its well-known antioxidant properties. The antioxidant, antibacterial, anti infammatory, anti-tyrosinase, and cytotoxicity potentials of aqueous and hydroethanolic extracts of V. myrtillus aerial parts were evaluated. Results From the obtained results, ultrasound-assisted and maceration extracts were found to be as efective as, if not more efective than, conventional antibiotics against methicillin-resistant Staphylococcus aureus. Aside from antibacterial activ ity, the extracts also showed antioxidant and anti-tyrosinase efects, which were found to be favourably related to the level of cafeoylquinic acid derivatives. Conclusion The obtained results highlight the bioactive potential and the importance of exploiting this bio residue as a novel candidate for industrial application, taking advantage of their biological properties. Graphical Abstract