Collagen-Stimulating Activity of Australian Sea Cucumber (Holothuria atra) Extracts on Human Skin Fibroblast Cells

Author: Gintung Patantis

Patantis, Gintung, 2017 Collagen-Stimulating Activity of Australian Sea Cucumber (Holothuria atra) Extracts on Human Skin Fibroblast Cells , Flinders University, School of Medicine

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Abstract

Sea cucumbers (traded as beche-de-mer) have a long history as a functional food and tonic in Asia. Sea cucumbers contain a wide range of bioactive compounds, which have huge potential applications in the nutraceutical and pharmaceutical industries. The compounds detected so far include collagen, gelatin, saponins, fucoidan, and glucosaminoglycones. Saponins, major secondary metabolites in sea cucumbers, are reported to have antibacterial, antifungal, antiprotozoal, antiviral, antioxidant, mutagenic, hemolytic, immunomodulation, and neurotoxic activity. However, very few studies on the cosmetic application of sea cucumber saponins are currently available. The aim of this study was to determine the potential application of saponins-rich extracts of sea cucumbers for cosmeceutical products. We hypothesize that saponins-rich extracts from sea cucumber have anti-aging properties similar to saponins from ginseng that have been widely studied. As a first step, the extraction methods were optimized by using two solvents (water and 70% ethanol (70%EtOH)), and the conditions of shaking at 22ºC (room temperature) and 60ºC, and sonication at 22ºC. The safe dosages for the extracts were then determined by cytotoxicity assays against human skin fibroblast cells CRL 2076 using crystal violet staining. Anti-aging properties of the extracts were assessed by measuring collagen production in human skin fibroblast cells and by quantifying antioxidant capacity through estimation of Ferric Reducing Antioxidant Power (FRAP). The extracts, were characterized (total saponins, sugar, total phenolics and soluble protein contents) and fingerprinted using thin-layer chromatography (TLC). The yields of water extracts were significantly higher than 70%EtOH extracts. In addition, the 70%EtOH extracts from shaking at 60C had significantly higher yields than other conditions; however the water extract was not significantly different. The safe dosages for sea cucumber extracts varied depending on extraction solvent and conditions and ranged from 2.5 - 10 mg/L extracts. At 2.5 mg/L concentration, the sea cucumber extracts increased the collagen production of human skin fibroblast cells up to 3.7-fold. Water extracts contained more antioxidant capacity compared to 70%EtOH extracts, however, the antioxidant capacities of the extracts were 100 times lower than common antioxidant sources such as green tea and grape. The chemical characterization of sea cucumber extracts contained 0.15 - 0.22 mg/ mg extract of saponins, 0.06 – 0.09 mg/ mg extract of sugar, 2.14 - 4.99 /mg extract of phenolics and 0.03- 0.12 mg/ mg extract of soluble protein. TLC showed different distribution of compounds between water and 70%EtOH extracts with 70%EtOH extracts exhibiting a greater number of compounds. Results indicate strong anti-aging properties of sea cucumber extracts on human skin cells and confirm their potential application for anti-aging skin care products.

Keywords: Collagen activity, Sea cucumber, Holothuria atra, Skin fibroblast cells

Subject: Biological Sciences thesis

Thesis type: Masters
Completed: 2017
School: School of Medicine
Supervisor: Prof. Wei Zhang