Limonene-induced regression of mammary carcinomas
This study found that dietary administration of limonene (a compound in the peel of lemons or other citrus fruits) caused complete reduction of mammary cancers in rats. In addition, with removal of limonene from the diet there was a significant number of tumor recurrences. These findings suggest that limonene has the potential to cause tumor regression with minimal toxicity. Further details can be found in the study.
Haag JD, Lindstrom MJ, Gould MN. Limonene-induced regression of mammary carcinomas. Cancer Res. 1992 Jul 15;52(14):4021-6.