We induced experimental nephrolithiasis in female rats using ethylene glycol (EG) and ammonium chloride (AC). We investigated the effects of carvacrol, an essential oil with antioxidant and anti-inflammatory properties, on nephrolithiasis using histopathology, immunohistochemistry and biochemistry. We used 40 female rats divided into four equal groups: control group, administered olive oil; carvacrol group, administered carvacrol in olive oil; nephrolithiasis group, administered EG and AC to induce experimental nephrolithiasis; treatment group with induced nephrolithiasis and administered carvacrol in olive oil. We observed no significant difference in crystal accumulation in the treatment group compared to the nephrolithiasis group. We found a significant reduction in hydropic degeneration of tubules and degree of inflammatory cell infiltration of intertubule areas. We also found a significant reduction in immunohistochemical staining of macrophage- and monocyte-specific antigens. Carvacrol treatment reversed the induced nephrolithiasis, increased malondialdehyde and urea, and decreased levels of glutathione peroxidase and catalase. Although carvacrol did not decrease crystal accumulation, it reduced pathological and biochemical damage, and improved kidney function by lowering the serum urea level.
Keywords: Carvacrol; ED1; hydropic degeneration; infiltration; inflammatory cell; nephrolithiasis; oxidative stress; rats.