Promoting effect of ginsenosides on hydrolysis activity of bovine testicular hyaluronidase

Testicular hyaluronidase is an endo-β-N-acetyl-d-hexosaminidase that hydrolyzes hyaluronan and is involved in fertilization. Recombinant hyaluronidase is used not only in fertility treatments but is also administered in combination with antibody drugs to promote their absorption during subcutaneous injection, and is applied as a treatment for malignant tumors. Compounds that regulate the activity of hyaluronidase are valuable for regulating biological processes involving hyaluronan and have possible future pharmaceutical applications. We screened a library consisting of single compounds derived from herbal medicine to find regulators of hydrolysis activity of bovine testicular hyaluronidase by assay using HPLC that is not affected by the absorption wavelength of the test compounds. While many compounds inhibit hyaluronidase activity, we have found that ginsenosides, the primary active ingredients in the roots of Panax ginseng, included in numerous traditional Chinese medicine formulas, promote hyaluronidase activity. Experiments using ginsenosides with various side chain structures suggested that the promoting effect of ginsenosides on BTH-catalyzed HA hydrolysis depends on structural differences in the side chains linked to the C-3 position of the steroid backbone of ginsenosides. The ginsenosides exhibiting strong stimulatory activity, ginsenoside-Rb1, -Rd, -Rg3, and -F2, all had an O-Glc(2-1)Glc or O-Glc structure at the C-3 position.