title: Autophagy induction by a natural ingredient of areca nut.
abstract: We recently identified an autophagy-inducing areca nut ingredient (AIAI) in the partially purified 30-100 kDa fraction of areca nut extract (ANE), designated as ANE 30-100K. Before disintegration, most ANE 30-100K-treated cells exhibit rounding morphology, cytoplasmic clearance, and nuclear shrinkage, distinct from arecoline- and cisplatin-induced cellular apoptosis. This unique death pattern is verified to be autophagy by LC3-I cleavage, acidic vesicles, and autophagic vacuoles. As analyzed by Molish's Test, Selinowaff's Test, and thin-layer chromatography, most of the ANE 30-100K constituents are carbohydrates, whereas the protein content of this fraction is less than 1% as assessed by protein assay reagent. The cytotoxicity of ANE 30-100K is further shown to be sensitive to cellulase and proteinase K digestion suggesting AIAI in ANE 30-100K to be a proteoglycan (or glycoprotein). Thus, although ANE contains apoptosis-inducing ingredients such as arecoline, it predominantly triggers autophagic cell death by this natural AIAI.
authors.affiliation: Department of Biotechnology, Chia Nan University of Pharmacy and Science, Tainan, Taiwan, ROC.
authors.forename: Mei-Huei
authors.initials: MH
authors.lastname: Lin
authors.forename: Shyun-Yeu
authors.initials: SY
authors.lastname: Liu
authors.forename: Young-Chau
authors.initials: YC
authors.lastname: Liu