Detoxification of aflatoxins by seed extracts of the medicinal plant, Trachyspermum ammi (L.) Sprague ex Turrill – Structural analysis and biological toxicity of degradation product of aflatoxin G1

Abstract

Aqueous extracts obtained from leaves/seeds of various medicinal plants were evaluated for their ability to detoxify aflatoxin G1 (AFG1) by thin-layer chromatography and enzyme-linked immunosorbent assay (ELISA). Of the various plant extracts, the seed extract of Ajowan ( Trachyspermum ammi (L.) Sprague ex Turrill) showed the maximum degradation of AFG1 up to 65%. The dialyzed T. ammi extract was more effective than the crude extract, capable of degrading >90% of the toxin. The aflatoxin detoxifying activity of the T. ammi extract was drastically reduced upon boiling at 100 °C for 10 min. Significant levels of degradation of other aflatoxins viz., AFB1 (61%), AFB2 (54%) and AFG2 (46%) by the dialyzed T. ammi extract was also observed. Time course study of AFG1 detoxification by dialyzed T. ammi extract showed that more than 78% degradation occurred within 6 h and 91% degradation occurred 24 h after incubation. Mass spectral analysis of the degradation products of AFG1 revealed that the most abundant molecular ion peak in positive-ion mode was at m/z 288.29. MS/MS analysis of precursor ion at m/z 288.29 showed fragment transition to m/z 270.16 corresponding to the loss of 18 D. Mass spectral analysis of the degradation products of AFG1 suggests the modification of lactone ring structure. AFG1 caused more than 2% chromosomal aberration in corn at 40 mg/l concentration. However, AFG1 after treatment with T. ammi extract failed to induce chromosomal aberration demonstrating the degradation of AFG1 by T. ammi extract. The T. ammi extract may provide a biologically safe method to protect poultry or livestock feeds and other agricultural commodities from aflatoxins.