Isolation of Compounds from Cyathea podophylla and their Cytoprotective Effects Against 6-Hydroxydopamine-Induced Toxicity In F11 Neuronal Cells

Cyathea podophylla is a fern species native to Vietnam whose chemical constituents and cytoprotective potential remain poorly investigated. This study aimed to isolate and identify compounds from C. podophylla and to evaluate their cytoprotective activity against 6-hydroxydopamine-induced cytotoxicity in a preliminary in vitro screening. Dried plant material was extracted and fractionated using chromatographic methods, and the isolated compounds were characterized by nuclear magnetic resonance spectroscopy and high-resolution electrospray ionization mass spectrometry. Cytoprotective activity was evaluated in F11 cells using the MTT assay against 6-hydroxydopamine-induced injury. Seven compounds were isolated, comprising five phenolic compounds — trans-cinnamic acid (DXH1), (E)-4-(3,4-dihydroxyphenyl)but-3-en-2-one (DXH3), p-coumaric acid (DXH4), 3,4-dihydroxybenzoic acid (DXH5) and 4-O-acetyl-caffeic acid (DXH8) — together with 5-hydroxymethylfurfural (DXH6) and butyl-β-D-fructofuranoside (DXH7); to our knowledge, six of these had not previously been reported in the genus Cyathea. Among the tested compounds, DXH7 exhibited the strongest cytoprotective effect, with 69.6% protection at 10 µM and significant activity at 2–10 µM (p < 0.001), while DXH3 showed significant but more modest protection at 5 and 10 µM. The remaining compounds were not significantly active. These findings expand the known phytochemical profile of C. podophylla and provide preliminary evidence that certain compounds exhibit cytoprotective activity against 6-hydroxydopamine-induced injury. These results are hypothesis-generating and require confirmation by orthogonal viability assays, mechanistic studies, and in vivo validation.