Ficus deltoidea standardized methanolic extract improves kidney structure and function against streptozotocin-induced diabetic nephropathy in rats

Abstract

Background

Oxidative stress and peripheral insulin resistance are the key pathogenesis of diabetic nephropathy. We have previously demonstrated that Ficus deltoidea increases insulin secretion and improves tissue regeneration by reducing oxidative stress in diabetic rats. However, it remains uncertain whether F. deltoidea could delay the progression of nephropathy.

Hypothesis/Purpose

This study aimed to examine the nephroprotective effects of F. deltoidea on streptozotocin-induced diabetic nephropathy in rats.

Methods

High-Performance Liquid Chromatography (HPLC) was used to identify the flavonoid compounds in the leaf extract of F. deltoidea. The methanolic extract of F. deltoidea was administered orally at 1000 mg/kg body weight for eight weeks to diabetic rats. Serum creatinine, urea, uric acid, total bilirubin, and urinary creatinine were measured to estimate kidney function. Enzyme-linked immunosorbent assays (ELISA) assessed the levels of oxidative stress, antioxidants, and apoptosis-related proteins in the kidney tissue. The spectral markers related to nephroprotective activity were predicted using Fourier-transform infrared (FTIR) spectroscopy combined with chemometric analysis. Histomorphometric evaluations were performed on the kidney sections stained with hematoxylin and eosin (H&E).

Results

HPLC identified the presence of vitexin, isovitexin, quercetin, and kaempferol in F. deltoidea methanolic leaves extract. The biochemical and histological examinations consistently showed that F. deltoidea extract improved kidney structure and function by reducing oxidative stress and apoptosis. We noticed that biochemical and pathological changes corresponded to the infrared (IR) peaks at 1545 cm^-1 and 1511 cm^-1 (amide II), 1246 cm^-1 (DNA/RNA phosphate backbones), and 1181 cm^-1 (C–O vibrations). Multivariate analysis of IR spectra demonstrated that the diabetic rats treated with F. deltoidea extract had a similar clustering pattern to that of the normal animals.

Conclusion

These findings indicate that the methanolic extract of F. deltoidea exhibits nephroprotective activity. FTIR spectroscopy may be useful for monitoring structural and biochemical alterations in the kidney during diabetes treatment.