title: Anti-neoplastic effects of gallic acid, a major component of Toona sinensis leaf extract, on oral squamous carcinoma cells.
abstract: Extract of Toona sinensis (TS) has been reported to have various effects on cultured cell lines, including anti-proliferative activity in cancer cells. We have studied the effects of TS on various human oral squamous carcinoma cell lines (HOSCC), including UM1, UM2, SCC-4, and SCC-9. These cell lines were treated with TS leaf extract and screened for viability, apoptosis, necrosis, and apoptotic gene expression. Normal human oral keratinocytes (NHOK) served as a control for cytotoxic assays. Viability of TS-treated HOSCC was reduced, whereas that of NHOK was not affected. FACScan analysis revealed that the leaf extract induced apoptosis or a combination of apoptosis and necrosis, depending on cell type. Microarray and semi-quantitative RT-PCR analysis for apoptotic-related gene expression revealed that 3,4,5-trihydroxybenzoic acid (gallic acid, one of the major bioactive compounds purified from TS extract) up-regulated pro-apoptotic genes such TNF-α, TP53BP2, and GADD45A, and down-regulated the anti-apoptotic genes Survivin and cIAP1, resulting in cell death. This study suggests that gallic acid, the major bioactive compound present, is responsible for the anti-neoplastic effect of Toona sinensis leaf extract.
authors.affiliation: Department of Food Science and Technology, Ta-Jen University, Ping Tung Hsien, Taiwan. ycchia@mail.tajen.edu.tw
authors.forename: Yi-Chen
authors.initials: YC
authors.lastname: Chia
authors.forename: Ranjan
authors.initials: R
authors.lastname: Rajbanshi
authors.forename: Colonya
authors.initials: C
authors.lastname: Calhoun
authors.forename: Robert H
authors.initials: RH
authors.lastname: Chiu
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D002294:Carcinoma, Squamous Cell; D018797:Cell Cycle Proteins / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D005707:Gallic Acid / Q000737:chemistry / Q000627:therapeutic use*; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D020128:Inhibitory Concentration 50; D015603:Keratinocytes / Q000187:drug effects; D029582:Meliaceae / Q000737:chemistry*; D009062:Mouth Neoplasms; D009687:Nuclear Proteins / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D000097642:GADD45 Proteins
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D051017:Apoptosis Regulatory Proteins; D018797:Cell Cycle Proteins; D005707:Gallic Acid; D009687:Nuclear Proteins; D010936:Plant Extracts; D014409:Tumor Necrosis Factor-alpha; C439070:GADD45A protein, human; D000097642:GADD45 Proteins; C090468:TP53BP2 protein, human