Abstract:

The aim of this study was to compare the difference of soluble protein components isolated from black garlic and
fresh garlic. Soluble proteins were isolated from garlic by serial extraction methods including grinding, ammonium sulfate
precipitation and gel filtration. Then, the antitumor activities of the extracts were determined in vitro using alamar blue
method; the antibacterial activities were detected by oxford cup assay; and the differences of soluble protein components
were further compared using SDS-PAGE. The results showed that the soluble protein components from both fresh garlic and
black garlic were able to inhibit the growth of HepG2 cells. The soluble protein components from fresh garlic had stronger
antitumor activity than those from fresh garlic and had heat resistance property. The soluble protein components from fresh
garlic could inhibit Escherichia coli and Staphylococcus aureus. SDS-PAGE results showed that the molecular weight of
soluble proteins in fresh garlic was in the range from 10 to 55 kD, and was about 10 kD for black garlic. This study indicated
that there were significant differences in soluble protein species and functions between black garlic and fresh garlic.

Key words: garlic, soluble protein, antitumor, antibacterial activity