Bioactive Potential of Rheum cordatum Losinsk. Leaf Extracts: Phytochemical Insights from Supercritical CO2, Subcritical Ethanol and Ultrasound-Assisted Extractions

Deep in Kazakhstan's flora hides a leaf that packs a powerful antioxidant and antimicrobial punch—and scientists just found the best way to unlock it.

Nature has a way of hiding its best secrets in plain sight. Rheum cordatum Losinsk., a plant native to Kazakhstan, has long been overlooked—until now. Researchers set out to explore its leaves using three cutting-edge, eco-friendly extraction methods: supercritical CO2, subcritical ethanol, and ultrasound-assisted extraction. The goal? To uncover the plant's hidden chemical treasures and test their biological powers.

The results were impressive. A total of 53 phytochemical compounds were identified, with gallic acid, rutin, and hesperidin standing out as the most abundant. But not all extractions were created equal. The supercritical CO2 extraction at 150 bar (ScCO2-150) proved to be the star performer, boasting the highest antioxidant activity and total phenolic content. It also showed strong antimicrobial effects, particularly against Bacillus subtilis, Pseudomonas aeruginosa, and Staphylococcus aureus.

These findings suggest that R. cordatum leaves are a rich, sustainable source of natural antioxidants and antimicrobials. And with supercritical CO2 as the winning extraction method, we're one step closer to turning this understudied plant into a valuable resource for health and medicine.

Key Points

• 53 phytochemicals found; gallic acid, rutin, hesperidin abundant
• ScCO2-150 shows top antioxidant activity and phenolic content
• Strong antimicrobial effects against three bacteria strains