Fig. 4.

Antibiotics prevent the appearance of activity (NF-kappa B activation of THP-1 cells) during the aseptic germination of surface sterilized alfalfa seeds. Alfalfa seeds were surface sterilized (successively washed with 70% ethanol and 10% clorox/0.01% Tween -20) and germinated in aseptic conditions in the presence or absence of 30 μg/ml ampicillin (amp) for seven days. Sterile solutions of chitin (50 mg/ml) were present in some of the flasks for 12 hours on day four. Sprouts were weighed, freeze dried, and the crude melanin fraction (0.1 μg/ml) assessed for activity in THP-1 human monocytes transfected with an NF-kappa B luciferase reporter plasmid. THP-1 cells were left untreated or treated for 4 hours with crude E. coli LPS (10 μg/ml) or with the melanin fraction from alfalfa seeds or sprouts germinated under the conditions specified. The value for each condition is the average ± standard deviation of three flasks (~50 sprouts each) with extracts from each flask run in duplicate in the THP-1 assay.