Anti-diabetic Activity of Oscarellin Isolated from Oscarella stillans in Zebrafish, a Model of Type 2 Diabetes

A new anthranilic acid derivative (1) was isolated from a Philippine sponge, Oscarella stillans (family Plakinidae. phylum Porifera, class Demospongiae, order Homosclerophorida) [1]. The structure of compound 1, named oscarellin, was determined as 2-amino-3-(3′-aminopropoxy)benzoic acid from spectral data, and confirmed by synthesis. We examined the anti-diabetic activity of compound 1 in zebrafish model for type 2 diabetes. The zebrafish model for type 2 diabetes was induced by exposure to excess insulin. Following exposure of excess insulin, the pancreatic islet size and fluorescence intensity were measured [2]. When compared to the insulin-treated group, the pancreatic islet size in oscarellin (1)-treated group was significantly increased at concentrations of 1 and 5µM. Glucose uptake was evaluated in zebrafish treated with compound 1 by detecting the uptake of 2-NBDG fluorescence within the pancreatic islets. Oscarellin (1)-treated group revealed significantly increased glucose uptake at concentration of 5µM. Compound 1 led to the recovery of pancreatic islet size and glucose uptake. In conclusion, oscarellin (1) possessed anti-diabetic activity for type 2.

This work was supported by a grant from Marine Biotechnology Program (PJT200620, Genome Analysis of Marine Organisms and Development of Functional Applications) funded by Ministry of Oceans and Fisheries.

[1] Kwon I-S, Kwak JH, Pyo S, Lee H-W, Kim A, Schmitz FJ. Oscarellin, J Nat Prod 2017; 80: 149 – 155

[2] Yang X, Mei S, Gu H, Guo H, Zha L, Cai J, Li X, Liu Z, Cao W. J Endocrinol 2014; 221: 469 – 480