Phytochemical Profile, Antioxidant, Anti-Alzheimer, And α-Glucosidase Inhibitory Effect Of Algerian Peganum harmala Seeds Extract.

Peganum harmala seeds crude hydro-methanolic extract and their fractions (obtained with ethyl acetate and butan-1-ol) were analyzed and compared for their chemical profiles of alkaloids and polyphenols content. Moreover, their antioxidant, a-glucosidase, acetylcholinesterase, and butyrylcholinesterase inhibitory activities were evaluated. The butan-1-ol fraction revealed the highest total phenolic content and exhibited the highest antioxidant capacity. From the inhibitory enzyme evaluations, it should be highlighted the butan-1-ol fraction inhibitory potential of ɑ-glucosidase (the IC50= 141.18±4µg/mL), which was better than the acarbose inhibitory effect (IC50= 203.41±1.07 µg/mL). The extracts' chemical profile analysis revealed several compounds, in which quercetin dimethyl ether, harmine and harmaline emerged as the major compounds. The different solvents used impacted Peganum harmala seed contents and biological responses. Statistical analysis showed a significant correlation between bioactive compounds and biological activities. Thus, Peganum harmala seeds could be a promising natural source of bioactive compounds at the crossroads of many human diseases, and its cultivation may be encouraged.

Exploring the fate of phlorotannins from Laminaria digitata across the gastrointestinal tract: Insights into susceptibility and bioactivity prior and post gastrointestinal digestion.

Phlorotannins are phenolic compounds exclusive from brown macroalgae endowed with promising bioactive properties. However, considering that diet is their main route of entrance to our system, gastrointestinal digestion might affect such bioactive properties. Here, phlorotannin extracts obtained from Laminaria digitata were submitted to simulated gastrointestinal digestion to evaluate its impact on their antioxidant and anti-inflammatory properties. Overall, a reduction of the total phlorotannin content along the gastrointestinal tract was noticed, although the antioxidant activity measured in vitro via NO● and O2●- scavenging assays, maintained almost the same. The crude extract (70 % v/v acetone) exhibited superior inhibition of NO● release on lipopolysaccharide-stimulated cells after digestion. In contrast, the opposite occurred to the phlorotannin-purified extract, indicating that the digestive process favors the anti-inflammatory properties of the former but not the latter. Data collected from UHPLC-MS analysis revealed that the fuhalol and carmalol-type compounds were completely absent from the digested phlorotannin-purified extract, which could partly explain its lower anti-inflammatory activity compared with its non-digested counterpart. Overall, this study contributes to a better understanding of the impact of gastrointestinal digestion on the bioactivity profile of L. digitata phlorotannins, demonstrating that fuhalols and carmalols are particularly susceptible to the digestive process.