Chemical composition and antimicrobial activity of Vitex agnus-castus L. fruits and leaves essential oils Dejan Stojkovic´ a , Marina Sokovic´ a,⇑ , Jasmina Glamocˇlija a , Ana Dzˇamic´ b , Ana C ´ iric´ a , Mihailo Ristic´ c , Dragoljub Grubišic´ a a Institute for Biological Research ‘Siniša Stankovic ´’, University of Belgrade, Bulevar Despota Stefana 142, 11000 Belgrade, Serbia b Institute of Botany and Jevremovac Botanical Garden, Faculty of Biology, University of Belgrade, 11000 Belgrade, Serbia c Institute for Medicinal Plant Research ‘Josif Pancˇic ´’, Tadeuša Košc ´uška 2, 11000 Belgrade, Serbia article info Article history: Received 25 January 2011 Received in revised form 3 March 2011 Accepted 4 April 2011 Available online 8 April 2011 Keywords: Antimicrobial Vitex agnus-castus Essential oils 1,8-Cineole Aspergillus apple rot Disease incidence abstract The following study deals with the chemical composition, antimicrobial activity of essential oils of Vitex agnus-castus L. and their main constituents in vitro and in vivo. The main compounds in the oil of unripe fruits were sabinene (17.8%) and 1,8-cineole (17.5%), while in the oil of the ripe fruits dominant compounds were 1,8-cineole (16.3%) and sabinene (13.4%). The leaves oil contained an abundance of 1,8-cineole (22.0%), as well. All of the oils tested were rich sources of a-pinene (12.2%, 9.4% and 9.4%, respectively). Antimicrobial activity was tested using bacterial and fungal strains by the microdilution method. Using the same technique 1,8-cineole and a-pinene showed very high antimicrobial potency as well. As 1,8-cineole was the predominant constituent of the oils, we have chosen to test it further in an in vivo experiment. Randomly chosen apples were treated with 1,8-cineol solution and infected with Aspergillus niger in order to provoke Aspergillus rot in apples. Disease incidence was recorded. Ó 2011 Elsevier Ltd. All rights reserved. 1. Introduction The growing awareness of consumers concerning the relation between food and health is revolutionary for the food industry. Current demand worldwide is to reduce or eliminate chemically synthesised additives from foods. Natural or synthetic products are used as agents with antimicrobial activity (as inhibitors, growth reducers or even inactivators) that control microorganisms’ growth. The application of preservatives to foods is crucial if their safety is to be maintained. The industries of food products nowadays are using synthetic chemical preservatives to prevent the growth of pathogens, but these chemicals, by increasing the activity of microsomal enzymes, convert the ingested materials into toxins and carcinogens (Farag, Daw, Hewedi, & El-Baroty, 1989). Natural antimicrobials, whether of microbial, animal or plant origin, which show bacteriostatic/fun- gistatic or bactericidal/fungicidal lengthen the useful life of foods and avoid, among other things, health-related problems, off- odours, unpleasant tastes, textural problems or changes in colour, which are basically caused by the enzymatic or metabolic systems of the principal microorganisms (Feng & Zheng, 2007). Essential plant oils are of growing interest both in the industry and scientific research because of their antibacterial and antifungal properties which make them useful as natural additives in foods (Pattnaik, Subramanyam, Bapaji, & Kole, 1997). Many in vitro stud- ies report a high efficacy of oils and extracts against food-borne pathogens and spoilage bacteria (Dorman & Deans, 2000; Kukic et al., 2008). The main advantage of essential oils is that they can be used in any foods and are considered generally recognised as safe (Kabara, 1991), as long as their maximum effects is attained with the minimum change in the organoleptic properties of the food. Such antimicrobial activity is due to the presence of bioactive substances such as flavonoids, terpenes, coumarines and carotenes (Tepe, Daferera, Sokmen, Sokmen, & Polissiou, 2005). Vitex agnus-castus L. (VAC) [Verbenaceae] is a deciduous shrub that is native to Mediterranean Europe and Central Asia. The aro- matic leaves are used as a spice. The fruits were formerly used as a substitute for pepper from Italy to Eastern Georgia, a use which is still reflected in the local culture, e.g. in some Italian synonyms of the plant’s name (‘albero del pepe’, ‘pepe falso’) (Hanelt, 2001). Traditionally, VAC fruit extract has been used in the treatment of many female conditions, including menstrual disorders (amenorrhoea, dysmenorrhoea), premenstrual syndrome (PMS), corpus luteum insufficiency, infertility, acne, menopause and dis- rupted lactation (Daniele, Thompson Coon, Pittler, & Ernst, 2005; Prilepskaya, Ledina, Tagiyeva, & Revazova, 2006). Because of its dopaminergic effect, VAC could be considered as an efficient alter- native phytotherapeutic drug in the treatment of slight hyperpro- lactinaemia (Meier, Berger, Hoberg, Sticher, & Schaffner, 2000). 0308-8146/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodchem.2011.04.007 ⇑ Corresponding author. Tel.: +381 11 2078 419; fax: +381 11 2761 433. E-mail address: mris@ibiss.bg.ac.rs (M. Sokovic´). Food Chemistry 128 (2011) 1017–1022 Contents lists available at ScienceDirect Food Chemistry journal homepage: www.elsevier.com/locate/foodchem