title: Anti-Trichomonas vaginalis properties of the oil of Amomum tsao-ko and its major component, geraniol.
abstract: BACKGROUND
  Trichomonosis, caused by the flagellate protozoan Trichomonas vaginalis, is the most common non-viral sexually transmitted disease (STD) and 5-nitroimidazole drugs are used for the treatment. However, a growing number of T. vaginalis isolates are resistant to these drugs, which make it becomes an urgent issue.
  
  
  OBJECTIVE
  The current study was designed to evaluate the anti-T. vaginalis activity of the essential oil from A. tsao-ko used in traditional Chinese medicine and as a spice and its main component, geraniol.
  
  
  METHODS
  The anti-T. vaginalis activities of A. tsao-ko essential oil and geraniol were evaluated by the minimum lethal concentration (MLC) and 50% inhibitory concentration (IC50) in vitro. The morphological changes of T. vaginalis were observed by transmission electron microscopy (TEM). Additionally, sub-MLC concentration treatment with sub-MLC A. tsao-ko essential oil and geraniol was also performed.
  
  
  RESULTS
  This study shows that MLC/IC50 of A. tsao-ko essential oil was 44.97 µg/ml/22.49 µg/ml for T. vaginalis isolate Tv1, and 89.93 µg/ml/44.97 µg/ml for T. vaginalis isolate Tv2. Those of geraniol were 342.96 µg/ml/171.48 µg/ml, respectively. After A. tsao-ko essential oil or geraniol treatment, obvious similar morphological changes of T. vaginalis were observed by TEM: the nuclear membrane was damaged, nuclei were dissolved, and the chromatin was accumulated; in the cytoplasm, numerous vacuoles appeared, rough endoplasmic reticulum dilated, the number of ribosomes were reduced, organelles disintegrated, the cell membrane was partially damaged, with cytoplasmic leakage, and cell disintegration was observed. The action time did not increase the effect of A. tsao-ko essential oil or geraniol against T. vaginalis, as no significant difference was observed after sub-MLC concentration treatment for 1, 3, and 5 h with A. tsao-ko essential oil and geraniol.
  
  
  CONCLUSIONS
  The study describes the first report on the activity and morphological changes of A. tsao-ko essential oil and geraniol against T. vaginalis. The results obtained herein presented new opportunities for antitrichomonal drugs.
authors.affiliation: a School of Medical Laboratory Science, Chengdu Medical College , Chengdu , Sichuan , PR China .
authors.forename: Min
authors.initials: M
authors.lastname: Dai
authors.affiliation: b State Key Laboratory of Systematic Research and Exploitation of Traditional Chinese Medicine Resources, College of Pharmaceuticals, Chengdu University of Traditional Chinese Medicine , Chengdu , Sichuan , PR China .
authors.forename: Cheng
authors.initials: C
authors.lastname: Peng
authors.affiliation: c School of Chinese Medicine, Li Ka Shing Faculty of Medicine, the University of Hong Kong , Hong Kong , PR China , and.
authors.forename: Fu
authors.initials: F
authors.lastname: Peng
authors.affiliation: d Sichuan Provincial Maternal and Child Health Hospital , Chengdu , Sichuan , PR China.
authors.forename: Chengbin
authors.initials: C
authors.lastname: Xie
authors.affiliation: a School of Medical Laboratory Science, Chengdu Medical College , Chengdu , Sichuan , PR China .
authors.forename: Pinjia
authors.initials: P
authors.lastname: Wang
authors.affiliation: a School of Medical Laboratory Science, Chengdu Medical College , Chengdu , Sichuan , PR China .
authors.forename: Fenghui
authors.initials: F
authors.lastname: Sun
mesh_terms: D000080462:Acyclic Monoterpenes; D035801:Amomum; D000981:Antiprotozoal Agents / Q000302:isolation & purification / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D009822:Oils, Volatile / Q000302:isolation & purification / Q000494:pharmacology*; D010938:Plant Oils / Q000302:isolation & purification / Q000494:pharmacology*; D013729:Terpenes / Q000494:pharmacology*; D014246:Trichomonas vaginalis / Q000187:drug effects* / Q000302:isolation & purification / Q000648:ultrastructure
chemical_list: D000080462:Acyclic Monoterpenes; D000981:Antiprotozoal Agents; D009822:Oils, Volatile; D010938:Plant Oils; D013729:Terpenes; C007836:geraniol
keywords: In vitro activity; morphological changes; transmission electron microscopy