ASSESSMENT OF A MICROPLATE-BASED BIOASSAY FOR THE DETECTION OF ECDYSTEROID-LIKE OR ANTIECDYSTEROID ACTIVITIES

We previously devised a simple and rapid bioassay for the detection of ecdysteroid agonistic and antagonistic activities based on the ecdysteroid-specific responses of the B(II) (l[2]mbn) tumorous blood cell line of Drosophila melanogaster. We have now assessed the bioassay's reproducibility, specificity and robustness. A characteristic response is obtained with a variety of ecdysteroids, but no response occurs in the presence of any of eight vertebrate steroids. The bioassay is robust enough to cope with methanol extracts of freeze-dried plant samples after hexane partition to remove plant pigments. Thus, the bioassay has all the required properties for receptor-based phytochemical screening of large numbers of plant samples for the purpose of identifying new potent phytoecdysteroids, non-steroidal ecdysteroid analogues and anti-ecdysteroids.