Deacetylated nimbin analog N2 fortifies alloxan-induced pancreatic β-cell damage in insulin-resistant zebrafish larvae by upregulating phosphoenolpyruvate carboxykinase (PEPCK) and insulin levels

Abstract

This study aims to evaluate the protective behaviour of N2, a semi-natural analog of nimbin, for its anti-diabetic efficacy against alloxan-induced oxidative damage and β-cell dysfunction in in-vivo zebrafish larvae. A 500 μM of alloxan was exposed to zebrafish larvae for 24 h to induce oxidative stress in the pancreatic β-cells and co-exposed with N2 to study the protection of N2 by inhibiting ROS by DCFH-DA, DHE and NDA staining along with Cellular damage, apoptosis and lipid peroxidation. The zebrafish was further exposed to 500 μM alloxan for 72 h to induce β-cell destruction along with depleted glucose uptake and co-exposed to N2 to study the protective mechanism. Glucose levels were estimated, and PCR was used to verify the mRNA expression of phosphoenolpyruvate carboxykinase (PEPCK) and insulin. Alloxan induced (24 h) oxidative stress in the pancreatic β-cells in which N2's co-exposure inhibited ROS by eliminating O−₂ radicals and restoring the glutathione levels, thus preventing cellular damage and lipid peroxidation. The zebrafish exposed to 500 μM alloxan for 72 h was observed with β-cell destruction along with depleted glucose uptake when stained with 2NBDG, wherein N2 was able to protect the pancreatic β-cells from oxidative damage, promoted high glucose uptake and reduced glucose levels. N2 stimulated insulin production and downregulated PEPCK by inhibiting gluconeogenesis, attenuating post-prandial hyperglycemia. N2 may contribute to anti-oxidant protection against alloxan-induced β-cell damage and anti-hyperglycemic activity, restoring insulin function and suppressing PEPCK expression.