Dietary antioxidant curcumin derived from turmeric has been suggested to decrease the risk of many chronic diseases. Much of the existing data for curcumin stem from experiments performed at supra-physiological concentrations (μM-mM) that are impossible to attain through oral ingestion. It was therefore hypothesized that curcumin at low plasma achievable concentration, though itself not acting as a direct antioxidant might up-regulate the intracellular antioxidants and thus helping combat oxidative stress and protect β-islet cells. The results indicated that Curcumin, DMC and BDMC were able to scavenge hydroxyl radicals, but showed little scavenging ability against superoxide and nitric oxide radicals. Nanomolar concentrations of curcuminoids easily prevented the deleterious effects of H<sub>2</sub>O<sub>2</sub> in pancreatic <i>β</i>-islet RINm5F cells. Non of the curcuminoids showed a detrimental effect on insulin secretion, but the model did not allow assessment of any potential positive effect on insulin secretion. The findings confirmed that nanomolar concentrations of curcumin offered protection in pancreatic <i>β</i>-islet cells against H<sub>2</sub>O<sub>2</sub>-indicated damage by modulating the proportion of oxidised GSH (GSSG): reduced GSH in the favour of GSH and the increasing the activity of SOD. This increase in GSH and SOD levels was, at least in part, on account of an increase in GR, SOD-1 and SOD-2 gene expression. The intracellular mechanism driving this modulation of antioxidant gene was, by virtue of blocking the H<sub>2</sub>O<sub>2 </sub> induced NF-κB activation.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:540318 |
| Date | January 2011 |
| Creators | Kanase, Nilesh |
| Contributors | Megson, Ian ; MacRury, Sandra |
| Publisher | University of the Highlands and Islands |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://pure.uhi.ac.uk/portal/en/studentthesis/the-impact-of-oxidative-stress-and-potential-antioxidant-therapy-on-function-and-survival-of-cultured-pancreatic-islet-cells(ec0cd703-3902-4410-8c58-e7c7e49f33e7).html |
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