Eight isoflavones extracted from kudzu, Pueraria lobata (WILLD.) OHWI, were tested for their effect on glyoxalase I [E.C. 4. 4. 1. 5] (G-I) activity. One of the isoflavones, 8-C-glucosyl-7, 3′, 4′-trihydroxyisoflavone, (PG-1) strongly inhibited the action of the enzyme at 100μM. However, its inhibitory activity was reduced at lower concentrations in comparison with that of baicalein or quercetin. Some of the remaining isoflavones had a moderate inhibitory effect on G-I, whereas others had a weak effect. All eight isoflavones were also tested for their effect on the growth of HF, a hybridoma cell line. However, none of them inhibited the growth of the hybridoma.
Proteolytic enzyme (s) was partially purified from a crude extract of acetone-dried powder of ginger rhizome. The purified preparation gave a single main protein band of approximately 30, 000 Da. on SDS-polyacrylamide gel electrophoresis and hydrolyzed casein (proteinase activity) and type 1 collagen from bovine achilles tendon (collagenase activity). The collagenase activity of ginger was not affected by addition of EDTA, which it is known to be a potent inhibitor of collagenases from other sources, but was inhibited by HgCl2. The proteinase and collagenase activities of the ginger preparation decreased at a similar rate during heat-treatment. These results are interpreted to indicate that ginger rhizome contains a single enzyme which has both proteinase and collagenase activities.