Essential Oils Studies on Respiratory & Fungal Pathogens

Sometime ago, I consulted with someone who was experiencing a serious mold problem in their home. After they had experts clean up the house they could still detect that mold/fungus was still present but was unable to locate the origin. They told me that they were experimenting with essential oils. At the time, I wasn't sure if this would help. Given the studies that I found below, this may be on track with what that person was working on. It appears that some EO's can breakdown those organisms.
 

http://sciencelinks.jp/j-east/article/200402/000020040203A0830301.php

Antibacterial Activity of Essential Oils against Pathogens Bacteria in Upper Airway Respiratory Tract

Accession number;03A0830301 Title;Antibacterial Activity of Essential Oils against Pathogens Bacteria in Upper Airway Respiratory Tract Author;TANAKA YASUO(Taiyokoryoken) KIKUZAKI HIROE(Sakashidai Daigakuin) NAKATANI NOBUJI(Sakashidai Daigakuin) Journal Title;Koryo, Terupen oyobi Seiyu Kagaku ni kansuru Toronkai Koen Yoshishu
Journal Code:L0852A
ISSN: VOL.47th;NO.;PAGE.303-305(2003) Figure&Table&Reference;FIG.1 Pub. Country;Japan Language;Japanese

Abstract;The antibacterial activity of 50 essential oils against upper airway respiratory tract bacteria such as Streptococcus pyogenes, Haemophilus influenzae, and Moraxella catarrhalis was examined. The essential oils of allspice, basil, black pepper, carrot, cinnamon leaf, cubeb, melissa, sage and savory inhibited the growth of the S. pyogenes. The antimicrobial test was also carried out on selected 47 volatile chemical compounds. Among the selected volatile constituents, (E,E)-farnesol showed the strongest antibacterial activity against S. pyogenes with an MIC of 12.5.MU.g/ml. Carvacrol, methyl chavicol, bornyl acetate, menthyl acetate, (E)-nerolidol, .ALPHA.-pinene, .ALPHA.-terpinyl acetate and viridiflorol showed the antimicrobial effect. (author abst.)

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http://www.springerlink.com/content/fu4m1q33v6050942/

Fungitoxicity of the essential oil of Citrus sinensis on post-harvest pathogens

Neeta Sharma¹ and Abhishek Tripathi¹

Mycology and Plant Pathology Division, Department of Botany, University of Lucknow, Lucknow, 226 007, India

Received: 7 April 2005 Accepted: 3 October 2005 Published online: 24 January 2006

Summary The essential oil extracted from the epicarp of Citrus sinensis exhibited absolute fungitoxicity against the 10 post-harvest pathogens. GC–MS studies of the oil revealed the presence of 10 chemical constituents, of which limonene was found to be the major component (84.2%). The activity of the oil was tested by the poisoned food technique (PF) and the volatile activity (VA) assay and the oils showed greater toxicity in the VA assay than in the poisoned food assay. The nature of the toxicity was studied in the VA assay and it was observed that the oil was fungicidal for the 10 pathogens in the 700 ppm (mg/l) to 1000 ppm range. The oil was extremely toxic for spore germination and it was found that at 700 ppm, spore germination was inhibited in the 10 test fungi out of the 12 tested. Treatment at 300 ppm concentration exhibited 70–100% inhibition of spore germination in most of the fungi tested. Scanning electron microscopy (SEM) was done to study the mode of action of the oil in Aspergillus niger and it was observed that treatment with the oil leads to distortion and thinning of the hyphal wall and the reduction in hyphal diameter and absence of conidiophores.

Keywords C itrus sinensis - fungitoxicity - GC–MS - post-harvest pathogens - SEM Neeta Sharma
Email: dr_neeta_sharma2003@yahoo.com

http://www.ncbi.nlm.nih.gov/pubmed/16784447?dopt=abstract

2006 Jul;49(4):316-23.

Related Articles, Links

In vitro efficacy of 75 essential oils against Aspergillus niger.

Pawar VC, Thaker VS.

Department of Biosciences, Saurashtra University, Rajkot, Gujarat, India.

Aspergillus niger is an opportunistic human pathogen and a strong air pollutant. A study was conducted with 75 different essential oils for the inhibition of hyphal growth and spore formation in Aspergillus niger. Cinnamomum zeylanicum (bark), Cinnamomum zeylanicum (leaf), Cinnamomum cassia, Syzygium aromaticum and Cymbopogon citratus were the top five essential oils which demonstrated marked inhibitory effect against hyphal growth and spore formation of A. niger. The chemical composition of these five most active essential oils was investigated by gas chromatography-mass spectra (GC-MS). Most of the other essential oils were found challenging to combat A. niger, suggesting their use as strong aroma therapeutic agents.

Publication Types:

· Research Support, Non-U.S. Gov't

PMID: 16784447 [PubMed - indexed for MEDLINE]

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http://www.ncbi.nlm.nih.gov/pubmed/16961209?ordinalpos=9&itool=EntrezSyst...

1998 Feb-Nov;40(1-4):59-61.

Effect of some essential oils on microorganisms.

Pandey R, Mehrotra N, Gaur R, Darmwal NS.

Department of Microbiology, Dr. R. M. L. Avadh University, Faizabad 224 001, India.

The essential oils tested viz., Cardiaca Oil, Mentha Oil, Artemisia Oil and Geranium Oil against pathogenic bacterial and fungal strains. Significant activity of all oils was found against all microorganisms. All the four oils showed a higher inhibition against all the microorganisms, except S. epidermidis at different level of concentrations used (1000 ppm and 500 ppm). It is clearly indicated that inhibition activity increased approximately 1 to 2 folds at 1000 ppm concentration as compared to 500 ppm. S. epidermidis has shown resistant towards all the oils at both the concentration while M. smegmatis and S. mutans have shown higher inhibition as compared to S. epidermidis.

PMID: 16961209 [PubMed - indexed for MEDLINE]

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http://www.ncbi.nlm.nih.gov/pubmed/10838841?ordinalpos=20&itool=EntrezSys...

2000;43(1-2):17-23

Inhibitory effect of essential oils on apical growth of Aspergillus fumigatus by vapour contact.

Inouye S, Tsuruoka T, Watanabe M, Takeo K, Akao M, Nishiyama Y, Yamaguchi H.

Research Center for Pathogenic Fungi and Microbial Toxicoses, Chiba University, Japan.

The inhibitory effect of seven essential oils on the apical growth of hyphae of Aspergillus fumigatus was studied using a bio cell tracer by vapour contact in a sealed vessel. Based on the inhibitory pattern, these essential oils were classified into three groups. The first group, composed of citron, lavender and tea tree oils, stopped the apical growth in a loading dose of 63 micrograms ml-1 air, but allowed the regrowth of the hyphae after removal of the vapour, indicating fungistatic action. The second group, consisting of perilla and lemon-grass oils, stopped the apical growth in a loading dose of 6.3 micrograms ml-1 air, and did not allow the regrowth after gaseous contact at 63 micrograms ml-1 air, indicative of fungicidal action. The third group, consisting of cinnamon bark and thyme oils, retarded the growth in a dose of 6.3 micrograms ml-1 air, stopped it in a dose of 63 micrograms ml-1 air, and incompletely suppressed regrowth of the hyphae. Gas chromatographic analysis revealed that vapours of essential oils were absorbed on fungal mycelia and agar medium most abundantly by the first group, followed by the second and third groups, reflecting the volatility of the respective groups. Suppression of the apical growth by vapour contact was ascribed to the direct deposition of essential oils on fungal mycelia, together with an indirect effect via the agar medium absorbed.

PMID: 10838841 [PubMed - indexed for MEDLINE]