Antifungal Activity of Essential Oils from Some Medicinal Plants of Iran against Alternaria alternate

Abstract

Problem statement: Increasing public concern over the level of pesticide residues in food especially fresh produce has built up adequate pressure for scientists to look for less hazardous and environmentally safer compounds for controlling post harvest diseases. Essential oils as registered food grade materials have the potential to be applied as alternative anti-fungal treatments for fresh fruits and vegetables. Approach: We present in this study, the identification of the essential oils with antifungal activity from some medicinal plants of Iran (nettle (Urtica dioica L.), thyme (Thymus vulgaris L.), eucalyptus (Eucalyptus spp.), Rue (Ruta graveolens L.) and common yarrow (Achillea millefolium L.)), and their potential application as "generally regarded as safe" antifungal compounds against Alternaria alternate on tomato as a model pathosystem. Results: Both the nettle and the thyme oils exhibited antifungal activity against A. alternata. The thyme oil exhibited a lower degree of inhibition 68.5 and 74.8% at 1500 and 2000 ppm, respectively. Spore germination and germ tube elongation of the pathogens in potato dextrose broth was strongly reduced in the presence of 1500 ppm of the nettle oil. The same concentration of this oil reduced the percentage of decayed tomatoes. The experiments on reducing the development of natural tomato rot gave similar results. Conclusions: Application of essential oils for postharvest disease control of fresh produce, as a novel emerging alternative to hazardous anti-fungal treatments will allow a safer and environmentally more acceptable management of postharvest diseases.

Phytochemical screening, antimicrobial and antioxidant efficacy of different extracts of Rumex dentatus L. – A locally used medicinal herb of Kashmir Himalaya

“…It was suggested that extract components cross the cell membrane, interacting with enzymes and proteins of the membrane, thus producing a flux of protons towards the cell exterior which induces changes in the cells and, ultimately their death [31] . It is evident from the results of the current study that susceptibility of pathogens to plant extracts depends upon solvent used for extraction, extract concentration and the organism tested as has been shown by many studies [32][33][34] . The aqueous extract of the plant inhibited none of the bacterial strains in comparison to the other extracts.…”

Inhibitory effect of essential oil from Nepeta rtanjensis on fungal spore germination

“…Sharma and Tripathi [8] examined the effects of Citrus sinensis (L.) Osbeck epicarp essential oil on Aspergillus niger conidia germination and reported that concentration of 1.5 μg ml -1 can cause 100% inhibition of conidia germination. Hadizadeh et al [9] reported inhibition effect of nettle (Urtica dioca L.) essential oil against Alternaria alternata (Fr.) Keissl.…”

Obtaining of the essential oil of Syzygium aromaticum, identification of eugenol and its effect on Streptococcus mutans.

“…The traditional use of clove is supported by its many properties which have been described in numerous scientific reports highlighting its antioxidant, hypotensive, dental analgesic 3 , antibacterial 4 , antiinflammatory 5 and antifungal 6 activity, apart from the synergistic antimicrobial activity of the essential oil with other plants 7 which allows it to be considered with great potential for dental application 8,9 . The oral cavity is considered as an ecosystem.…”