Diabetes mellitus represents a global health problem. It characterized by hyperglycemia that induces oxidative stress leading to a generation of free radicals. A wide variety of natural products in plants and other marine animals represent antioxidant activity and other health benefits like those of sea cucumber. Therefore, this study aimed to investigate the antidiabetic activity of glycosidic compound – saponin – derived from the Egyptian sea cucumber, Holothuria thomasi.

Saponin has been extracted from the Egyptian sea cucumber and confirmed by hemolysis, Salkowski tests, FT/IR, UV and GC–MS analysis.

Eighty white female albino rats were divided into four equal groups. The first two groups of rats; control normal and control normal saponin-treated groups. The last two groups which were made diabetic by intraperitoneal injection of streptozotocin had one diabetic control and the other diabetic group that got 300mg/kg B.wt. of saponin extract after Thirty-five days after diabetes induction and lasted for six weeks.

The functional group of saponin extract which established with FT/IR spectroscopy demonstrated the presence of saponin in the extracted materials as shown in the peak of the functional group in relevance to the standard one. The UV spectra revealed that λ_max of saponin extract was 282nm which in accordance to the standard saponin. Also, GC–MS analysis indicated that the aglycone part of saponin was methyl esters of octadecanoic acid. Saponin extract significantly decreased serum glucose, α-amylase activity, adiponectin, IL-6, TNF-α concentrations and liver L-MDA. However, serum insulin and liver glycogen levels were significantly increased as compared with the diabetic non-treated groups. The histopathological results supported that saponin extract markedly reduced the degenerative change in β-cells.

This study, therefore, depicts that the Egyptian Holothuria thomasi, sea cucumber saponin as a hypoglycemic agent with the potential to normalize aberrant biochemical parameters and preserved the normal histological architecture of the islets cells of pancreatic tissues.