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- Phenolic compounds from Actinidia deliciosa leaves: Caco-2 permeability, enzyme inhibitory activity and cell protein profile studiesPublication . Henriques, Joana; Fale, Pedro; Pacheco, Rita; Florêncio, Maria Helena; Serralheiro, Maria LuisaChemical compounds from leaves of fruit-producing trees, a waste from agricultural activity can be isolated and used as a source of natural bioactive chemicals. Boiling water was used as an extractant of bioactive compounds from Actinidia deliciosa leaves and co-extracted fibres were removed with ethanol precipitation. Rutin and quercitrin were the main flavonoids identified and quantified by RP-HPLC-DAD. No cytotoxicity was detected for any of the extracts towards Caco- 2 cell line. A permeation of approx. 14% of extract components through the cells monolayer was determined. The cell protein profile of Caco-2 cells was modified when in the presence of the fibre-free extract and transketolase was the protein over-expressed in the presence of polyphenols. Acetylcholinesterase inhibitory activity was also studied, IC50 of 0.56 mg/mL was obtained with the fibre-free extract. A. deliciosa leaves are a good source of phenolic compounds and, therefore, some advantage may be taken of this agricultural residue, due to their biological activity.
- Phenolic profile and biological activities of decoctions from Santolina impressa, a Portuguese endemic speciesPublication . Rodrigues, Ana M.; Fale, Pedro; Madeira, Paulo; Pacheco, Rita; Florêncio, Maria Helena; Ascensão, Lia; Serralheiro, Maria LuisaSantolina impressa Hoffmanns & Link is an aromatic Asteraceae species endemic to the southwest of Portugal. It is used in folk medicine as an herbal tea for gastrointestinal ailments and mouthwash antiseptic. The present study aimed to relate the chemical composition of decoctions from the aerial parts S. impressa with their antiacetylcholinesterase, antioxidant, antimicrobial and cytotoxic activities, in an attempt to explain the traditional use of this species. LC–MS/MS analysis identified chlorogenic acid and cynarin as the main components. Antimicrobial activity of the extracts was investigated against two cariogenic bacteria:- Streptococcus sobrinus and Streptococcus mutans, and these decoctions were not cytotoxic towards Caco-2 and HepG2 cell lines. Decoctions from capitula and stems/leaves showed high AChE inhibition, with IC50 values of 328 μg/mL and 579 μg/mL, respectively. The antioxidant activity measured using the DPPH radical scavenging assay showed an EC50 of 14.7 μg/mL and 12.9 μg/mL for capitula and stems/leaves extracts, respectively. The biological activities were kept constant after in vitro digestive process and the HPLC analysis did not indicate changes in the extract’s chemical composition. The results may explain the traditional use of S. impressa decoctions for digestive problems and as a mouthwash antiseptic.
- Antiacetylcholinesterase activity and docking studies with chlorogenic acid, cynarin and arzanol from Helichrysum stoechas (Lamiaceae)Publication . Silva, Leticia; Rodrigues, Ana M.; Ciriani, Marina; Fale, Pedro Luís Vieira; Teixeira, Vítor; Madeira, Paulo; Machuqueiro, Miguel; Pacheco, Rita; Florêncio, Maria Helena; Ascensão, Lia; Serralheiro, Maria LuisaThis work was aimed at the study of the chemical composition in phenolic compounds responsible for the high antiacetylcholinesterase activity of aqueous extracts (decoctions) from Helichrysum stoechas aerial parts. Chlorogenic acid, cynarin, and arzanol were the main components of decoctions, detected by high-performance liquid chromatography with diode-array detection and liquid chromatography-mass spectrometry/mass spectrometry. Flowers and stems/leaves extracts inhibited antiacetylcholinesterase with IC50 values of 260.7 and 654.8 mu g/mL, respectively. The biological activity of these extracts was maintained after in vitro gastrointestinal digestion, indicating that the active compounds present in the extracts were not enzymatically modified by the gastrointestinal system used to simulate the digestion. Molecular docking studies with the main components were carried out in order to obtain information, at the molecular level, as to how these compounds access the enzyme's active site. The docking study showed for the first time that chlorogenic acid, cynarin, and arzanol fit nicely in the antiacetylcholinesterase active site channel, blocking all access to the catalytic triad. This explained the high inhibitory activity determined during in vitro experiments.
- Antiacetylcholinesterase activity and docking studies with chlorogenic acid, cynarin and arzanol from Helichrysum stoechas (Asteraceae)Publication . Silva, Letícia; Rodrigues, Ana M.; Ciriani, Marina; Falé, Pedro Luís Vieira; Teixeira, Vitor; Madeira, Paulo; Machuqueiro, Miguel; Pacheco, Rita; Florêncio, Maria Helena; Ascensão, Lia; Serralheiro, Maria LuisaThis work was aimed at the study of the chemical composition in phenolic compounds responsible for the high antiacetylcholinesterase activity of aqueous extracts (decoctions) from Helichrysum stoechas aerial parts. Chlorogenic acid, cynarin, and arzanol were the main components of decoctions, detected by high-performance liquid chromatography with diode-array detection and liquid chromatography-mass spectrometry/mass spectrometry. Flowers and stems/leaves extracts inhibited antiacetylcholinesterase with IC50 values of 260.7 and 654.8 μg/mL, respectively. The biological activity of these extracts was maintained after in vitro gastrointestinal digestion, indicating that the active compounds present in the extracts were not enzymatically modified by the gastrointestinal system used to simulate the digestion. Molecular docking studies with the main components were carried out in order to obtain information, at the molecular level, as to how these compounds access the enzyme’s active site. The docking study showed for the first time that chlorogenic acid, cynarin, and arzanol fit nicely in the antiacetylcholinesterase active site channel, blocking all access to the catalytic triad. This explained the high inhibitory activity determined during in vitro experiments.
- Valorization of kiwifruit production: leaves of the pruning branches of Actinidia deliciosa as a promising source of polyphenolsPublication . Henriques, Joana; Ribeiro, Maria João; Fale, Pedro L; Pacheco, Rita; Ascenso, Lia; Florêncio, Maria Helena; Serralheiro, Maria LuisaThe present work concerns the novel application of a phenolic compound extraction methodology to leaves of Actinidea deliciosa. Recent studies have shown that crop residues could be raw material for recovery of natural bioactive compounds. Phenolic compounds from Actinidea deliciosa leaves were extracted with hot water, purified using reverse phase chromatography and mucilage precipitation with ethanol. The composition of the purified fraction was determined by HPLC-DAD and LC-MSn. Quercitrin, rutin, proantocyanidin B and C, quinic acid, myricitrin, and triterpene acid-O-hexoside were found. These compounds were present in all the fractions. The antioxidant activity was determined as general radical scavenging capacity, lipid peroxidation prevention, and NO radical scavenging activity. Values of EC50 of 9.4 mu g/mL, IC50 of 152.5 mu g/mL, and IC50 of 81 mu g/mL were determined, respectively. The best period of the year to obtain a high fraction of phenolic compounds (120 A mu g/mg of extract) from A. deliciosa leaves was December. The phenolic fraction obtained with hot water and ethanol precipitation is a promising good source of natural bioactive compounds and an easy method of taking advantage of the leaves from A. deliciosa. To the best of our knowledge, there are no previous works on the use of the residual leaves of this fruit tree. Several phenolic compounds with high antioxidant activity were extracted and identified in this plant for the first time.