Inhibition of Hyaluronidase Activity byVitis rotundifolia. (Muscadine) Berry Seeds and Skins

Hyaluronidase hydrolyzes glycosaminoglycans including hyaluronan (HA) in the extracellular matrix during tissue remodeling. Upregulation of hyaluronidase activity occurs in chronic inflammatory conditions (e.g., inflammatory joint disease). Prior work demonstrated that Vitis rotundifolia. Michx (muscadine) skin extracts possess significant in vitro. and in vivo. anti-inflammatory activities. In this study, we tested the ability of muscadine skin and seed extracts to inhibit in vitro. hyaluronidase activity. Ethanol extracts (1:9 w/v 50% ethanol) were prepared from dried skins and seeds of Early Fry (bronze) and Ison (purple) muscadine varieties. Each extract inhibited hyaluronidase activity. Seed extracts were two to three times more potent per unit weight than skin extracts. The IC50 values of the Ison seed, Early Fry seed, Ison skin, and Early Fry skin were 0.3, 0.6, 1.0, and 1.0 mg/mL, respectively. Hyaluronidase inhibition correlated positively with total phenolic and ferric-reducing antioxidant power (FRAP) values, but not with anthocyanin content. In addition to anti-inflammatory and antioxidant properties, the results of this study show that polyphenolics in muscadine grapes inhibit hyaluronidase. These three bioactivities are important for maintaining healthy connective tissue metabolism.