Lyoniresinol 3α-O-β-D-Glucopyranoside-Mediated Hypoglycaemia and Its Influence on Apoptosis-Regulatory Protein Expression in the Injured Kidneys of Streptozotocin-Induced Mice

Averrhoa carambola L. (Oxalidaceae) root (ACLR) has a long history of use in traditional Chinese medicine for treating diabetes and diabetic nephropathy (DN). (±)-Lyoniresinol 3α-O-β-D-glucopyranoside (LGP1, LGP2) were two chiral lignan glucosides that were isolated from the ACLR. The purpose of this study was to investigate the effect of LGP1 and LGP2-mediated hypoglycaemia on renal injury in streptozotocin (STZ)-induced diabetic mice. STZ-induced diabetic mice were administrated LGP1 and LGP2 orally (20, 40, 80 mg/kg body weight/d) for 14 days. Hyperglycaemia and the expression of related proteins such as nuclear factor-κB (NF-κB), caspase-3, -8, -9, and Bcl-associated X protein (Bax) were markedly decreased by LGP1 treatment. However, LGP2 treatment had no hypoglycaemic activity. Diabetes-dependent alterations in the kidney such as glomerular hypertrophy, excessive extracellular matrix amassing, and glomerular and tubular basement membrane thickening were improved after 14 days of LGP1 treatment. B cell lymphoma Leukaemia-2 (Bcl-2) expression was reduced in the STZ-induced diabetic mouse kidneys but was enhanced by LGP1 treatment. These findings suggest that LGP1 treatment may inhibit diabetic nephropathy progression and may regulate several pharmacological targets for treating or preventing diabetic nephropathy.