title: Proteomics indicates modulation of tubulin polymerization by L-menthol inhibiting human epithelial colorectal adenocarcinoma cell proliferation.
abstract: Menthol is a naturally occurring cyclic monoterpene used in oral hygiene products, confectionary, pharmaceuticals, cosmetics, pesticides, and as a flavoring agent. In the present study, we analyzed the differentially expressing proteome in L-menthol-treated Caco-2 cell line as it was found to inhibit cell proliferation. Interestingly, free tubulin proteins were observed to be limited after menthol treatment. Semiquantitative RT-PCR with α-tubulin primers showed no change in the level of RNA expression in menthol-treated cell line. However, tubulin polymerization assay with menthol indicated a trend similar to taxol in promoting microtubule assembly. Further, physical counting of apoptotic nuclei and active caspase-3 assays confirmed onset of apoptosis though the rate was slower as compared with that of taxol treatment. This study is the first report of a monoterpene L-menthol modulating tubulin polymerization and apoptosis to inhibit cancer cell proliferation.
authors.affiliation: Biotechnology Division, Central Institute of Medicinal and Aromatic Plants (CSIR), Lucknow, Uttar Pradesh, India.
authors.forename: Uzma
authors.initials: U
authors.lastname: Faridi
authors.forename: Brijesh S
authors.initials: BS
authors.lastname: Sisodia
authors.forename: Ashutosh K
authors.initials: AK
authors.lastname: Shukla
authors.forename: Rakesh K
authors.initials: RK
authors.lastname: Shukla
authors.forename: Mahendra P
authors.initials: MP
authors.lastname: Darokar
authors.forename: Upendra N
authors.initials: UN
authors.lastname: Dwivedi
authors.forename: Ajit K
authors.initials: AK
authors.lastname: Shasany
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D017209:Apoptosis / Q000187:drug effects; D018938:Caco-2 Cells; D048708:Cell Growth Processes / Q000187:drug effects; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D015180:Electrophoresis, Gel, Two-Dimensional; D005434:Flow Cytometry; D006801:Humans; D008610:Menthol / Q000494:pharmacology*; D008856:Microscopy, Fluorescence; D058105:Polymerization / Q000187:drug effects; D040901:Proteomics / Q000379:methods*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014404:Tubulin / Q000378:metabolism*
chemical_list: D014404:Tubulin; D008610:Menthol