Histomorphometric Analysis of Hyaline Droplet Formation in Renal Tissue of Nephrolithiasis-Induced Rats Treated with Avocado Leaf and Gooseberry Extracts

Nephrolithiasis, commonly known as kidney stone disease, can be experimentally induced in animal models using ethylene glycol (EG) in combination with ammonium chloride, which closely mimics calcium oxalate stone formation in humans. This condition is associated with significant renal tissue injury, including glomerular atrophy, tubular necrosis, and hyaline droplet accumulation, ultimately impairing kidney function. The present study aimed to investigate the histopathological changes in the kidneys of EG-induced rats and evaluate the nephroprotective potential of combined avocado (Persea americana) and gooseberry (Physalis angulata) leaf extracts. A total of 30 male Sprague Dawley rats were randomly divided into five groups: a standard control (no induction), a negative control (EG-induced without treatment), a positive control (EG-induced and treated with a commercial nephroprotective agent), and two treatment groups receiving the combined extracts at different doses. Nephrolithiasis induction was performed over 28 days, followed by oral administration of the respective treatments. At the end of the experiment, kidney tissues were collected and processed for histological examination using hematoxylin-eosin staining to assess the extent of tissue damage. The negative control group exhibited the most severe histopathological alterations, with hyaline droplet formation reaching 15.0 ± 5.25%. In contrast, extract-treated groups demonstrated a marked reduction in tissue damage, with the most significant improvement observed in the group receiving 300 mg/kg avocado extract and 100 mg/kg gooseberry extract, which recorded hyaline droplet formation of only 5.27 ± 2.74%, a result comparable to that of the standard control group. These findings suggest that the combination of P. americana and P. angulata leaf extracts confers protective effects against EG-induced renal injury. Therefore, this herbal combination may represent a promising natural nephroprotective agent that warrants further investigation in preclinical and clinical settings.