Polyphenols from Litsea Genus: Phytochemistry, Analytical Methods, and Molecular Mechanisms Underlying Therapeutic Potential

Abstract

The genus Litsea (Lauraceae family) represents a rich source of polyphenolic compounds with significant therapeutic potential. This comprehensive review synthesizes current knowledge on polyphenol composition, extraction and analytical methods, and molecular mechanisms underlying the biological activities of Litsea species. A total of 126 polyphenol compounds have been isolated and characterized from various Litsea species, including 67 flavonoids, 46 lignans, 8 phenolic acids and related compounds, and 5 coumarins. Ultrasound-assisted extraction (UAE) demonstrated the highest efficiency with total phenolic content (TPC) of 276.38±11.88 mg GAE/g and total flavonoid content (TFC) of 72.53±6.43 mg QE/g in Litsea cubeba. Advanced analytical techniques including UPLC-Q-TOF-MS/MS, UHPLC-MS, and NMR have been successfully applied for structural identification. The extracts and isolated compounds exhibit potent antioxidant activity, α-glucosidase inhibition, in vivo hypoglycemic effects in STZ-diabetic mice, cytotoxic activity against cancer cell lines, and analgesic effects through inhibition of substance P signaling in the spinal cord. However, detailed molecular mechanistic data on NF-κB, MAPK, Nrf2, and caspase pathways remain limited. This review identifies promising compounds for drug development and proposes future research directions focusing on mechanistic studies, bioavailability enhancement, and clinical trials.