Polygonum cognatum Extract: Multitarget Anti-inflammatory, Antidiabetic, and Epigenetic Modulation Properties

Area of Science:

• Phytochemistry
• Pharmacology
• Medicinal Plants

Background:

• Polygonum cognatum (Madımak) is traditionally used in Turkey for medicinal purposes.
• Geographical origin and collection time significantly impact the phytochemical profile of medicinal plants.
• Previous studies on P. cognatum have not comprehensively characterized its phytochemicals and multitarget bioactivities from a specific region and growth phase.

Purpose of the Study:

• To conduct a comprehensive phytochemical characterization of P. cognatum from the Central Black Sea Region (Tokat) during its vegetative growth phase.
• To evaluate the multitarget biological activities, including antioxidant, anti-inflammatory, antidiabetic, antimicrobial, and histone deacetylase (HDAC) inhibitory effects, of P. cognatum extracts.
• To identify key compounds responsible for the observed bioactivities and explore potential therapeutic applications.

Main Methods:

• Extraction of P. cognatum using solvents of varying polarities (hexane, ethanol, water).
• Phytochemical profiling using advanced analytical techniques: liquid chromatography-tandem mass spectrometry (LC-MS/MS), high-performance liquid chromatography-diode array detector (HPLC-DAD), and gas chromatography-mass spectrometry (GC-MS).
• Assessment of biological activities: antioxidant (DPPH assay), anti-inflammatory (COX-1/COX-2 inhibition), antidiabetic (α-amylase and α-glucosidase inhibition), antimicrobial (MIC determination), and HDAC inhibition assays. Molecular docking studies were performed to correlate binding affinities with experimental data. Cytotoxicity was evaluated using CC50 assays.

Main Results:

• Identification of 28 phenolic compounds, with the ethanol extract exhibiting the highest diversity (24 compounds) and total phenolic content.
• Novel compounds isoquercetin-3-O-rhamnoside, apigenin-7-O-glucoside, and luteolin-4'-O-glucoside were identified for the first time in P. cognatum.
• The ethanol extract demonstrated potent antioxidant, selective anti-inflammatory (COX-2 preferential inhibition), significant antidiabetic, and antimicrobial activities. Notably, P. cognatum exhibited significant histone deacetylase (HDAC) inhibitory activity for the first time, indicating epigenetic modulation potential. Key compounds like quercetin, rutin, chlorogenic acid, and kaempferol were identified as major contributors to these activities. Cytotoxicity evaluation showed a favorable safety profile (CC50 > 500 μg/mL).

Conclusions:

• P. cognatum, particularly the ethanol extract from the Central Black Sea Region, is rich in phenolic compounds and possesses significant multitarget biological activities.
• The plant demonstrates novel histone deacetylase (HDAC) inhibitory properties, suggesting potential in epigenetic-related therapies.
• These findings support the development of P. cognatum as a promising therapeutic agent for inflammatory, metabolic, and epigenetic disorders.