Essential oils of Heliotropium bacciferum, Ocimum dhofarense and Zataria multiflora exhibit aflatoxin B1 detoxification potential

The contamination of foods with aflatoxins, a group of carcinogenic compounds produced by some filamentous fungi belonging to Aspergillus section Flavi, is the major food safety concern worldwide. Various pre- and post-harvest techniques have been employed to minimize the level of aflatoxins in food commodities. The present study aimed to explore the potential of essential oils (EOs) derived from the medicinal herbs viz., Heliotropium bacciferum, Ocimum dhofarense and Zataria multiflora to detoxify aflatoxin B1 (AFB1). The EOs extracted from H. bacciferum, O. dhofarense and Z. multiflora exhibited 82.6, 92.0 and 67.9% degradation of AFB1, respectively as determined by ELISA. In the laboratory tests, EO of Z. multiflora was very effective in inhibiting the growth of Aspegillus flavus, whereas EOs of H. bacciferum and O. dhofarense did not show inhibitory activity towards A. flavus. Gas chromatography-mass spectrometry analysis of the EOs showed the presence of α-pinene (32.9%) and β-myrcene (9.4%) in H. bacciferum, germacrene D (41%), bicyclogermacrene (16.4%) and germacrene B (13.7%) in O. dhofarense and linalool (27.5%) and bornyl acetate (15.4%) in Z. multiflora as the major components. To our knowledge, this is the first study demonstrating detoxification of AFB1 by EOs of medicinal plants.