Antibacterial activities of the crude ethanol extracts of medicinal plants against Listeria monocytogenes and some other pathogenic strains

Searches for substances with antimicrobial activity are frequent and medicinal plants have been considered interesting by some researchers since they are frequently used in popular medicine as remedies for many infectious diseases. The aim of this study was to verify the antibacterial effect of ethanol extracts of 13 plants (Artemisia Herba Alba, Lavandula officinalis L., Matricaria Chamomilla, Eugenia caryophylata , Cistus salvifolius, Mentha suaveolens subsp. Timija, Thymus serpyllum L.,Lippia citriodora, Cinnamomum Zeylanicum, Rosa centifolia, Thymus vulgaris L, Rosmarinus officinalis and Pelargonium graveolens) against Listeria monocytogenes and other pathogenic strains. These plants are used more for their therapeutic effects in the aromatization of the traditionally fermented dairy products. For this purpose, the agar well diffusion method was the antimicrobial susceptibility performed test. The major components of extracts tested were identified by gas chromatography coupled with mass spectrometry (GC/MS) analysis. The obtained results revealed in vitro anti-Listeria monocytogenes activities of all the extracts. Also, the extracts of clove, mint timija, cinnamon, cistus,rose, thyme, wild thyme, artemisia, rosemary, geranium and camomile presented in this order promises inhibitory capacity with MIC value between 0.25 mg/mL for clove extract and 6.75 mg/mL for camomile extract. On the other hand, the antimicrobial activity was mainly a function of their chemical composition, in particular in the nature of their major volatile compounds. This study thus confirmed the possibility of using these plants or some of their components in food systems to prevent the growthof foodborne bacteria and to extend the shelf-life of processed foods

Plants of genus Mentha: From farm to food factory

Genus Mentha, a member of Lamiaceae family, encompasses a series of species used on an industrial scale and with a well-described and developed culture process. Extracts of this genus are traditionally used as foods and are highly valued due to the presence of significant amounts of antioxidant phenolic compounds. Many essential oil chemotypes show distinct aromatic flavor conferred by different terpene proportions. Mint extracts and their derived essential oils exert notable effects against a broad spectrum of bacteria, fungi or yeasts, tested both in vitro or in various food matrices. Their chemical compositions are well-known, which suggest and even prompt their safe use. In this review, genus Mentha plant cultivation, phytochemical analysis and even antimicrobial activity are carefully described. Also, in consideration of its natural origin, antioxidant and antimicrobial properties, a special emphasis was given to mint-derived products as an interesting alternative to artificial preservatives towards establishing a wide range of applications for shelf-life extension of food ingredients and even foodstuffs. Mentha cultivation techniques markedly influence its phytochemical composition. Both extracts and essential oils display a broad spectrum of activity, closely related to its phytochemical composition. Therefore, industrial implementation of genus Mentha depends on its efficacy, safety and neutral taste.This work was supported by the Vice-chancellor for Research Affairs of Shahid Beheshti University of Medical Sciences, Tehran, Iran and Vicerrectoría de Investigación y Desarrollo from University of Concepción, Chile (216.073.031-1.0IN and 217.073.033-1.0). A. Sureda was supported by the Programme of Promotion of Biomedical Research and Health Sciences (CIBEROBN CB12/03/30038). Acknowledgments: N.M. thank to Portuguese Foundation for Science and Technology (FCT–Portugal) for the Strategic project ref. UID/BIM/04293/2013 and “NORTE2020-Programa Operacional Regional do Norte” (NORTE-01-0145-FEDER-000012)

In Vitro Antibacterial and Antifungal Activity of Lavandula x intermedia Emeric ex Loisel. ‘Budrovka’

This study aimed to evaluate the in vitro antibacterial and antifungal activities of Lavandula x intermedia Emeric ex Loisel. ‘Budrovka’, an indigenous Croatian cultivar of lavandin. For that purpose the activity of ethanolic extracts of flowers, inflorescence stalks and leaves against thirty one strains of bacteria, yeasts, dermatophytes and moulds were studied using both the agar well diffusion and broth dilution assays. Among the investigated extracts found to be effective against a broad spectrum of microorganisms, the flower extract was considered to be the most potent one. Linalool and rosmarinic acid, as the most abundant constituents found, are very likely major contributors to the observed antimicrobial effects. The results suggest that flowers of lavandin ‘Budrovka’ could serve as a rich source of natural terpene and polyphenol antimicrobial agents