Induction of protein droplet (alpha 2 mu-globulin) nephropathy in male rats after short-term dosage with 1,8-cineole and l-limonene.

As part of a series of short-term studies on peppermint oil constituents for their possible induction of the encephalopathy found with peppermint oil, 1,8-cineole and l-limonene were studied. Groups of 10 male Wistar rats were given 0, 500, or 1000 mg 1,8-cineole/kg body wt./day or 0, 800, or 1600 mg l-limonene/kg body wt./day for 28 days. 1,8-Cineole and l-limonene both induced accumulation of protein droplets containing alpha 2 mu-globulin in proximal tubular epithelial cells in male rats. These results suggest that both 1,8-cineole and l-limonene possibly belong to the group of chemicals characterized by their induction of excessive alpha 2 mu-globulin accumulation. Neither of the 2 substances induced encephalopathy.