Tetrahydrocurcumin Enhances Islet Cell Function and Attenuates Apoptosis in Mouse Islets

• Published in: Transplantation proceedings Vol. 50; no. 9; pp. 2847 - 2853
• Main Authors: Kim, S.S., Jang, H.J., Oh, M.Y., Lee, J.H., Kang, K.S.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-11-2018
• Subjects: Animals; Antioxidants - pharmacology; Apoptosis - drug effects; Curcumin - analogs & derivatives; Curcumin - pharmacology; Cytokines - biosynthesis; Cytokines - drug effects; Ischemia - prevention & control; Islets of Langerhans - drug effects; Islets of Langerhans Transplantation - methods; Mice; Mice, Inbred BALB C
• ISSN: 0041-1345; 1873-2623
• DOI: 10.1016/j.transproceed.2018.03.033

The transplantation of isolated pancreatic islets is a promising treatment for diabetes. Curcumin has been used for its pharmacologic effects, such as antidiabetic and anti-inflammatory activities. Tetrahydrocurcumin (THC), one of the major metabolites of curcumin, has been reported to have antioxidant and anti-inflammatory activities. This study examines the hypothesis that preoperative THC treatment can attenuate ischemic damage and apoptosis before islet transplantation.
Islets isolated from Balb/c mice were randomly divided into 2 groups and cultured in medium supplemented with or without THC. In vitro islet viability and function were assessed. After treatment with a cytokine cocktail consisting of tumor necrosis factor-α, interferon-β, and interleukin-1β, islet cell viability, function, and apoptotic status were determined. Proteins related to apoptosis were analyzed using INS-1 cell after streptozocin treatment.
There was no difference in cell viability between the 2 groups. Islets cultured in the medium supplemented with THC showed 1.3-fold higher glucose-induced insulin secretion than the islets cultured in the medium without THC. After treatment with a cytokine cocktail, glucose-induced insulin release, and NO of the islets were significantly improved in THC-treated islets compared with islets not treated with THC. Apoptosis was significantly decreased, and B-cell lymphoma-2 was elevated in the THC-treated group. The streptozocin-treated INS-1 cell produced significantly higher levels of and B-cell lymphoma-2-associated X protein, caspase-3, and caspase-9 than INS-1 treated with THC.
These results suggest that preoperative THC administration enhances islet function before transplantation and attenuates the cytokine-induced damage associated with apoptosis.
•Tetrahydrocurcumin (THC) is one of the major metabolites of curcumin.•THC has been reported to have antioxidant, anti-inflammatory, and antiapoptotic activities.•THC enhances insulin secretion.•Treatment with THC enhanced glucose-induced insulin secretion.•Glutathione levels were significantly elevated in the THC-treated group.•THC-treated islets attenuated expression of NO, B-cell lymphoma-2-associated X protein, caspase-3, and apoptosis.•THC treatment enhanced islet function before transplant and attenuated cytokine-induced damage associated with NO production and apoptosis.