Saponin-enriched extracts from body wall and cuvierian tubule of Holothuria leucospilota reduce fat accumulation and suppress lipogenesis in Caenorhabditis elegans.

BACKGROUND: Saponins have been showed to possess many pharmacological properties including altered fat metabolism. The black sea cucumber, Holothuria leucospilota, is a marine animal that contains a specialized organ called cuvierian tubules that produce and secrete the bioactive saponins into the tubules and body wall. Therefore, the aims of this study are to investigate the anti-obesity effect of saponins extracted from body wall and cuvierian tubules of H. leucospilota.

RESULTS: The butanol extracts of H. leucospilota body wall and cuvierian tubules (BW-BU and CT-BU) containing high amount of saponins significantly reduced fat deposition and triglyceride levels in Caenorhabditis elegans induced with 50 mM glucose. Moreover, the saponin-enriched extracts of H. leucospilota significantly restored lifespan of 2% glucose-induced worms (18.71%). GFP-labeled sbp-1 gene expression and nuclear translocation of daf-16 were also significantly decreased in H. leucospilota treatment. The saponin-enriched extracts down-regulated the mRNA expressions of genes involved in fat storage and metabolism, including sbp-1, cebp, and daf-16 while up-regulated the expression of nhr-49 gene.

CONCLUSION: Our results suggest that H. leucospilota-derived saponins may mediate the reduction of glucose-induced fat accumulation through sbp-1, cebp, daf-16 and nhr-9 pathways. Therefore, the H. leucospilota extracts could be used as nutraceuticals for anti-obesity prevention. This article is protected by copyright. All rights reserved.