A Study on Chemical Characterization and Biological Abilities of Alstonia boonei Extracts Obtained by Different Techniques

Abstract

In the quest for novel therapeutic agents from plants, the choice of extraction solvent and technique plays a key role. In this study, the possible differences in the phytochemical profile and bioactivity (antioxidant and enzyme inhibitory activity) of the Alstonia boonei leaves and stem bark extracted using water, ethyl acetate and methanol, and different techniques, namely infusion, maceration and Soxhlet extraction, were investigated. Data collected showed that methanol extracts of both A. boonei leaves (48.34–53.08 mg gallic acid equivalent [GAE]/g dry extract) and stem bark (37.08–45.72 mg GAE/g dry extract) possessed higher phenolic content compared to the ethyl acetate extracts (leaves: 30.64–40.19 mg GAE/g; stem bark: 34.25–35.64 mg GAE/g). The methanol extracts of A. boonei leaves showed higher radical scavenging and reducing capacity, and these findings were in accordance with phenolic content results. In general, water extracts of A. boonei leaves and stem bark obtained by infusion were poor inhibitors of acetylcholinesterase, α-amylase, α-glucosidase, and tyrosinase, except for butyrylcholinesterase. The chemical profiles of the extracts were determined by UHPLC–MS and the presence of several compounds, such as phenolic acids (caffeic, chlorogenic and ferulic acids, etc.), flavonoids (rutin and isoquercetin) and flavonolignans (Cinchonain isomers). Cell viability was tested using the human peripheral blood monocytic cell line (THP-1), and the extracts were safe up to 25 μg/mL. In addition, anti-inflammatory effects were investigated with the releasing of IL-6 TNF-α and IL-1β. In particular, stem bark extracts exhibited significant anti-inflammatory effects. Data presented in this study highlight the key role of solvent choice in the extraction of bioactive secondary metabolites from plants. In addition, this study appraises the antioxidant and enzyme inhibitory action of A. boonei leaves and stem bark, which are extensively used in traditional medicine.

Anti-SARS-CoV-2 Activity of Ampelozizyphus amazonicus (Saracura-Mirá): Focus on the Modulation of the Spike-ACE2 Interaction by Chemically Characterized Bark Extracts by LC-DAD-APCI-MS/MS

“…Moreover, flavonoids are known for their potential ability to regulate inflammatory mediators and inhibit endothelial activation, among other factors, which might be beneficial in regulating the cytokine storm during SARS-CoV-2 infection, and may positively influence inflammatory changes associated with COVID-19 [ 57 ]. Additionally, phenol-rich extracts from plants have also demonstrated antiinflamatory activity [ 58 , 59 ].…”

Antioxidant, Tyrosinase, α-Glucosidase, and Elastase Enzyme Inhibition Activities of Optimized Unripe Ajwa Date Pulp (Phoenix dactylifera) Extracts by Response Surface Methodology

“…As stated by Mollica et al [ 51 ], the maceration process was carried out with continuous stirring. Briefly, the plant materials (10 g) were soaked in 200 mL of the solvents, and extractions were performed with stirring at 250 rpm for 24 h at room temperature.…”

Phytochemical Composition,In VitroAntimicrobial, Antioxidant, and Enzyme Inhibition Activities, andIn SilicoMolecular Docking and Dynamics Simulations ofCentaurea lycaonica: A Computational and Experimental Approach

“…ABTS solution was diluted with methanol to an absorbance of 0.700 ± 0.02 at 734 nm to begin the assay. Then the sample solution was added to the ABTS solution, and the color change was recorded …”

“…Then the sample solution was added to the ABTS solution, and the color change was recorded. 12 In the FRAP assay, the FRAP values of extract and fractions were determined at 2, 1, and 0,5 mg/mL concentrations. 11 In this assay, the change of color was recorded at 593 nm.…”