Detoxification of aflatoxin B1 by an aqueous extract from leaves of Adhatoda vasica Nees. (Special Issue: Medicinal extracts in microbiology.)

摘要

The effectiveness of aqueous extracts of various medicinal plants in detoxification of aflatoxin B1 (AFB1) was tested in vitro by thin-layer chromatography and enzyme-linked immunosorbent assay (ELISA). Among the different plant extracts, the leaf extract of Vasaka (Adhatoda vasica Nees) showed the maximum degradation of AFB1 (>=98%) after incubation for 24 h at 37 degrees C. The aflatoxin detoxifying activity of the A. vasica leaf extract was significantly reduced by heating to 100 degrees C for 10 min or autoclaving at 121 degrees C for 20 min. Dialysis had no effect on aflatoxin detoxifying ability of A. vasica extract and the dialyzed extract showed similar level of detoxification of AFB1 as that of the untreated extract. A time course study of aflatoxin detoxification by A. vasica extract showed that 69% of the toxin was degraded within 6 h and >=95% degradation was observed after 24 h of incubation. Detoxification of AFB1 by A. vasica extract was further confirmed by liquid chromatography-mass spectrometry (LC-MS) analysis. Phytochemical analysis revealed the presence of alkaloids in methanolic extract of A. vasica leaves. A partially purified alkaloid from A. vasica leaves by preparative TLC exhibited strong AFB1 detoxification activity.