Review and perspective on Chemical Constituents and Bioactivities of Turnip (Brassica rapa L.)

Abstract

Turnip  (Brassica rapa L.), a medicinal and edible plant of the Brassicaceae family, has garnered significant attention due to its diverse chemical constituents and multi-target bioactivities. This review systematically summarizes the characteristics and functional mechanisms of its core bioactive components. It reveals that the contents of polysaccharides (9.10%–16.32%, reaching up to 21.78% in specific varieties), flavonoids (2.805%–3.2%), and glucosinolates (1.5–187 mmol/kg) in turnip are significantly higher than in most plants of the same family, with their accumulation being dually regulated by environmental factors and genetic background. Recent studies have unveiled significant biological effects of various active components in turnip: its pectic polysaccharides activate macrophage immune function via the TLR4/NF-κB signaling pathway, with experimental data showing they can increase the secretion of the pro-inflammatory cytokine TNF-α by approximately 150%. Particularly noteworthy, polysaccharides from turnip exert antitumor effects by regulating signaling pathways such as PI3K/AKT. Both in vitro and in vivo experiments have confirmed their inhibitory rates on specific lung cancer cells reach 55%-71%. However, compared to the well-characterized polysaccharides and flavonoids, research on seed peptides remains largely unexplored, necessitating breakthroughs in separation techniques (e.g., matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, MALDI-TOF), enzymatic hydrolysis processes, and synergistic effect evaluation systems. This review not only systematically elucidates the structure-activity relationships of turnip›s active constituents but also provides crucial theoretical support for the development of functional products.
Keywords: Turnip, Bioactive compounds, Polysaccharides, Flavonoids