title: Seasonal variation in content, chemical composition and antimicrobial and cytotoxic activities of essential oils from four Mentha species.
abstract: BACKGROUND
  The aim of the present study was to appraise variation in the chemical composition, and antimicrobial and cytotoxic activities of essential oils from the leaves of four Mentha species-M. arvensis, M. piperita, M. longifolia and M. spicata-as affected by harvesting season. Disc diffusion and broth microdilution susceptibility assays were used to evaluate the antimicrobial activity of Mentha essential oils against a panel of microorganisms. The cytotoxicity of essential oils was tested on breast cancer (MCF-7) and prostate cancer (LNCaP) cell lines using the MTT assay.
  
  
  RESULTS
  The essential oil contents of M. arvensis, M. piperita, M. longifolia and M. spicata were 17.0, 12.2, 10.8 and 12.0 g kg(-1) from the summer and 9.20, 10.5, 7.00 and 9.50 g kg(-1) from the winter crops, respectively. Gas chromatographic-mass spectrometric analysis revealed that mostly quantitative rather than qualitative variation was observed in the oil composition of each species. The principal chemical constituents determined in M. arvensis, M. piperita, M. longifolia and M. spicata essential oils from both seasons were menthol, menthone, piperitenone oxide and carvone, respectively. The tested essential oils and their major components exhibited notable antimicrobial activity against most of the plant and human pathogens tested. The tested essential oils also exhibited good cytotoxicity potential.
  
  
  CONCLUSIONS
  Of the Mentha essential oils tested, M. arvensis essential oil showed relatively better antimicrobial and cytotoxic activities. A significant variation in the content of most of the chemical components and biological activities of seasonally collected samples was documented.
authors.affiliation: Department of Chemistry, GC University, Faisalabad 38040, Pakistan.
authors.forename: Abdullah I
authors.initials: AI
authors.lastname: Hussain
authors.forename: Farooq
authors.initials: F
authors.lastname: Anwar
authors.forename: Poonam S
authors.initials: PS
authors.lastname: Nigam
authors.forename: Muhammad
authors.initials: M
authors.lastname: Ashraf
authors.forename: Anwarul H
authors.initials: AH
authors.lastname: Gilani
mesh_terms: D000890:Anti-Infective Agents / Q000032:analysis / Q000494:pharmacology*; D000972:Antineoplastic Agents, Phytogenic / Q000032:analysis / Q000494:pharmacology* / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy; D045744:Cell Line, Tumor; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008297:Male; D027541:Mentha / Q000737:chemistry* / Q000145:classification; D039821:Monoterpenes / Q000032:analysis / Q000494:pharmacology*; D009369:Neoplasms / Q000188:drug therapy*; D009822:Oils, Volatile / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use; D008517:Phytotherapy; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use; D011471:Prostatic Neoplasms / Q000188:drug therapy; D012621:Seasons; D013045:Species Specificity
chemical_list: D000890:Anti-Infective Agents; D000972:Antineoplastic Agents, Phytogenic; D039821:Monoterpenes; D009822:Oils, Volatile; D010936:Plant Extracts