title: Discovery of hyaluronidase inhibitors from natural products and their mechanistic characterization under DMSO-perturbed assay conditions.
abstract: The present study discovered four novel hyaluronan-degrading enzyme (hyaluronidase) inhibitors including chikusetsusaponins and catechins through the activity-guided separation of Panax japonicus and Prunus salicina, respectively. Although the discovery resulted in identification of usual frequent hitters, subsequent mechanistic characterizations under our DMSO-perturbed assay conditions and related protocols revealed that chikusetusaponin IV would serve as an aggregating and non-specific binding inhibitor, while (-)-epicatechin would interact specifically with enzyme at the catalytic site or more likely at a kind of catechin-binding site with a relatively week inhibitory activity. The latter description might provide a possible explanation for the well-known fact that a series of catechin have been described as frequent hitters in biological assays with a moderate activity. Thus, the present study demonstrated a practical and robust methodology to characterize initial screening hits mechanistically molecule-by-molecule in the early stage of natural product-based drug discovery.
authors.affiliation: Department of Hospital Pharmacy, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan. Electronic address: tomohara@med.u-toyama.ac.jp.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Tomohara
authors.affiliation: Department of Hospital Pharmacy, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Ito
authors.affiliation: Department of Hospital Pharmacy, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Saika
authors.initials: S
authors.lastname: Onikata
authors.affiliation: Department of Hospital Pharmacy, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kato
authors.affiliation: Department of Hospital Pharmacy, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan. Electronic address: adachi@med.u-toyama.ac.jp.
authors.forename: Isao
authors.initials: I
authors.lastname: Adachi
mesh_terms: D000818:Animals; D001665:Binding Sites; D002392:Catechin / Q000737:chemistry; D002417:Cattle; D004121:Dimethyl Sulfoxide / Q000737:chemistry*; D055808:Drug Discovery; D057075:Enzyme Assays; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000302:isolation & purification; D019695:Glycyrrhizic Acid / Q000737:chemistry; D006821:Hyaluronoglucosaminidase / Q000037:antagonists & inhibitors* / Q000737:chemistry; D008297:Male; D017830:Octoxynol / Q000737:chemistry; D005894:Panax / Q000737:chemistry*; D010936:Plant Extracts / Q000494:pharmacology; D000068242:Prunus domestica / Q000737:chemistry*; D012503:Saponins / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D004791:Enzyme Inhibitors; D010936:Plant Extracts; D012503:Saponins; C000606734:chikusetsusaponin IV; C588229:chikusetsusaponin V; D019695:Glycyrrhizic Acid; D002392:Catechin; D017830:Octoxynol; D006821:Hyaluronoglucosaminidase; D004121:Dimethyl Sulfoxide
keywords: Catechin; Concentration-response curve; DMSO; Hyaluronidase inhibitor; Non-specific binding