In vitro Antioxidant and Anticholinesterase Activities of Ouratea fieldingiana (Gardner) Eng. Leaf Extract and Correlation with Its Phenolics Profile with an in silico Study in Relation to Alzheimer’s Disease

Ouratea fieldingiana is a native medicinal plant from Northeastern Brazil and many biological properties are due to the phenolic constituents. The objective of this work was performing the characterization of O. fieldingiana leaf constituents to correlate with antioxidant and anticholinesterase activities by in vitro and in silico studies and thus contribute to find new agents against Alzheimer’s disease. The high-performance liquid chromatography revealed the presence of the flavonoids rutin, isoquercitrin, kaempferol-3-O-rutinoside, quercetin, apigenin and amentoflavone. The antioxidant activities by the (2,2-diphenyl-1-picrylhydrazyl) (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) methodologies, showed good results with half maximal inhibitory concentration (IC50) values ranging from 5.63 to 11.47 μg mL-1 and 2.72 to 23.71 μg mL-1, respectively. Acetylcholinesterase inhibition assay pointed out the flavone apigenin with best activity. Computational studies evaluated the interaction of flavonoids with the enzyme acetylcholinesterase co-crystallized with the galantamine, used as standard. All flavonoids exhibited binding energy greater than that of galantamine, but only apigenin showed strong interaction with the active site of the enzyme and other bind probably to different allosteric centers. Then, O. fieldingiana extract and flavonoids with good anti-radical activity and presenting a broad-spectrum action against acetylcholinesterase (AChE) enzyme ought to be tested in clinical studies to discover new neuro-therapeutic candidates.

Arsenic content and phenolic compounds in parsley (Petroselinum crispum (Mill.) Fuss) and celery (Apium graveolens L.) cultivated in Vojvodina region, Serbia

Randomly collected samples of parsley and celery from different localities were analyzed to determine their quality based on arsenic concentrations, phenolic constituents and the antioxidant capacity of their edible parts. Arsenic concentrations were found in the range: parsley root (0.16 μg/g d.m.) < celery root (0.19 μg/g d.m.) < parsley leaf (0.35 μg/g d.m.) < celery leaf (0.45 μg/g d.m.). Total phenolic contents in roots were similar in both species and varied significantly depending on the cultivation site: 5.03-9.18 mg eqGA/g DE in parsley and 5.04-8.50 mg eqGA/g DE in celery. Lower total flavonoids content was recorded in celery. Among the phenolic acids, ferulic, chlorogenic and several cinnamic acids dominated. Apigenin and its glucosides dominated among flavonoids. Based on the principal component analysis (PCA) it can be concluded that the As content varied depending on the geographical origin of the samples. Also, phenolic compounds showed a significant contribution on PCA clustirng, indicating that cultivation site has a clear significant impact on the metabolites profile, while As content in plants did not significantly affect phenolic compound profile.

Molecular Docking Studies on Phenolic Constituents of Anethum graveolens L. Seed Extracts

Background: There are studies indicating that aqueous or hydroalcoholic dill extracts showed higher antioxidant activity compared to other fractions. Molecular docking studies would be relevant to get information on the mechanism of action of the phenolic constituents of Anethum graveolens seed extracts as bioactive compounds. Methodology: In order to perform the docking studies of antioxidant activity of phenolic constituents of Anethum graveolens seed extracts, BIOVIA Discovery Studio and AutoDock Vina software were used. Results: The orientation of flavonoids within Hck and CYP2C9 binding sites has been shown to be the main reason for their inhibitory potency. Conclusion: Molecular docking studies indicate that the compounds identified interact with the target enzymes Hck and CYP2C9 at molecular level through their condensed ring systems and hydroxyl substituents and therefore support the antioxidant capacity of the studied phenolic compounds.

Phenolic Constituents of Anethum graveolens Seed Extracts: Chemical Profile and Antioxidant Effect Studies

The Aim of the Research: Anethum graveolens (dill) is a common herb used in traditional Romanian cuisine, as well as in phytotherapy. Dill seeds have been reported to be rich in antioxidants. As interest in food additives of natural origin has increased in recent years, the purpose of this paper was to study the composition and antioxidant potential of Romanian dill seeds. Methodology: In this study, the total phenolics contents, the phenolic profile, and the antioxidant properties of the methanolic and hydromethanolic extracts of Romanian dill seeds were investigated. Folin-Ciocalteu assay, DPPH spectrophotometrically method and reverse-phase high-performance liquid chromatography RP-HPLC, respectively were applied. Results: The highest content of total phenolics was found in acidified methanol samples (46.5 - 46.8 mg GAE/g dry seeds). RP-HPLC analysis highlights important content of quercetin, kaempferol, caffeic acid, sinapic acid, gallic acid, vanillic acid, (±) - catechin and umbelliferone. Antioxidant activity, measured via DPPH free radical scavenging ability, showed very high values (93.5 - 95.6% for the crude extracts and 67.5 - 93.2% for extracts at a concentration of 0.25 mg/mL). Methanolic extract exhibited the best IC50 value (88.7 ± 0.01 μg/mL). Conclusion: All experiments proved the antioxidant activity of dill seed extracts.

Food Processing Technologies to Develop Functional Foods With Enriched Bioactive Phenolic Compounds in Cereals

Cereal grains and products provide calories globally. The health benefits of cereals attributed to their diverse phenolic constituents have not been systematically explored. Post-harvest processing, such as drying, storing, and milling cereals, can alter the phenolic concentration and influence the antioxidant activity. Furthermore, cooking has been shown to degrade thermo-labile compounds. This review covers several methods for retaining and enhancing the phenolic content of cereals to develop functional foods. These include using bioprocesses such as germination, enzymatic, and fermentation treatments designed to enhance the phenolics in cereals. In addition, physical processes like extrusion, nixtamalization, and parboiling are discussed to improve the bioavailability of phenolics. Recent technologies utilizing ultrasound, micro- or nano-capsule polymers, and infrared utilizing processes are also evaluated for their effectiveness in improving the phenolics content and bio-accessibility. We also present contemporary products made from pigmented cereals that contain phenolics.

Evaluation of phenolic constituents and antioxidant potential of green coffee beans from Planalto de Conquista (Bahia) by Multivariate Analysis

The chemical composition and bioactivity of green coffee is influenced by both intrinsic and extrinsic factors, and it is a rich source of bioactive compounds, including phenolic compounds, alkaloids, and many compounds with antioxidant and anti-inflammatory properties. These characteristics have sparked numerous studies on its chemical composition and, consequently, have been attributed numerous advantages and disadvantages for human health. This study aimed to quantify the total phenolic constituents and analyze the in vitro antioxidant activity of green coffee from the Conquista Plateau region, Bahia, Brazil, and separate them according to their antioxidant potential. The total phenolic content (TPC) was determined and the evaluation of the in vitro antioxidant potential was investigated by the DPPH radical scavenging methods and the β-carotene:linoleic acid (BCLA) system co-oxidation method. Principal component analysis (PCA) was applied to reveal which samples showed higher and lower antioxidant potential. The results showed that the samples presented moderate content of total phenolic constituents 27.02 mg. g-1 of sample, low primary antioxidant activity with the average value of 65.17 EC50 mg. g-1 sample and moderate secondary antioxidant activity with 44% protection from oxidation of the β-carotene molecules present, moderately inhibiting the conditions favorable to oxidation that were inserted during the analysis. The principal components analysis proved efficient in the separation and classification of the green coffee samples, allowing the observation of the dispersion and heterogeneity among the samples, demonstrating different composition and bioactivity profiles.