Inhibitory effects of Satureja hortensis L. essential oil on growth and aflatoxin production by Aspergillus parasiticus.
In an effort to screen the essential oils of some Iranian medicinal plants for novel aflatoxin (AF) inhibitors, Satureja hortensis L. was found as a potent inhibitor of aflatoxins B1 (AFB1) and G1(AFG1) production by Aspergillus parasiticus NRRL 2999. Fungal growth was also inhibited in a dose-dependent manner. Separation of the plant inhibitory substance(s) was achieved using initial fractionation of its effective part (leaf essential oil; LEO) by silica gel column chromatography and further separation by reverse phase-high performance liquid chromatography (RP-HPLC). These substances were finally identified as carvacrol and thymol, based on the interpretation of 1H and 13C NMR spectra. Microbioassay (MBA) on cell culture microplates contained potato-dextrose broth (PDB) medium (4 days at 28 degrees C) and subsequent analysis of cultures with HPLC technique revealed that both carvacrol and thymol were able to effectively inhibit fungal growth, AFB1 and AFG1 production in a dose-dependent manner at all two-fold concentrations from 0.041 to 1.32 mM. The IC50 values for growth inhibition were calculated as 0.79 and 0.86 mM for carvacrol and thymol, while for AFB1 and AFG1, it was reported as 0.50 and 0.06 mM for carvacrol and 0.69 and 0.55 mM for thymol. The results obtained in this study clearly show a new biological activity for S. hortensis L. as strong inhibition of aflatoxin production by A. parasiticus. Carvacrol and thymol, the effective constituents of S. hortensis L., may be useful to control aflatoxin contamination of susceptible crops in the field.
Razzaghi-Abyaneh
Mehdi
M
Department of Mycology, Pasteur Institute of Iran, Tehran 13164, Iran. mrab442@pasteur.ac.ir
Shams-Ghahfarokhi
Masoomeh
M
Yoshinari
Tomoya
T
Rezaee
Mohammad-Bagher
MB
Jaimand
Kamkar
K
Nagasawa
Hiromichi
H
Sakuda
Shohei
S
D016604:Aflatoxin B1 / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D000348:Aflatoxins / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D000935:Antifungal Agents / Q000494:pharmacology*; D001230:Aspergillus / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003257:Consumer Product Safety; D000081007:Cymenes; D004305:Dose-Response Relationship, Drug; D005506:Food Contamination / Q000517:prevention & control*; D005519:Food Preservation / Q000379:methods; D006801:Humans; D020128:Inhibitory Concentration 50; D039821:Monoterpenes / Q000032:analysis / Q000494:pharmacology; D009822:Oils, Volatile / Q000494:pharmacology*; D010938:Plant Oils / Q000494:pharmacology; D031362:Satureja / Q000737:chemistry*; D013943:Thymol / Q000032:analysis / Q000494:pharmacology
D000348:Aflatoxins; D000935:Antifungal Agents; D000081007:Cymenes; D039821:Monoterpenes; D009822:Oils, Volatile; D010938:Plant Oils; C027955:aflatoxin G1; D013943:Thymol; C073316:carvacrol; D016604:Aflatoxin B1