The effects of naturally occurring monoterpenes on lung metastasis induced by B16F-10 melanoma cells were studied in C57BL/6 mice. Administration of monoterpenes such as limonene (100 micromoles/kg body wt. 10 doses i.p.) and perillic acid (50 micromoles/kg body wt 10 doses i.p.) remarkably reduced the metastatic tumour nodule formation by 65% and 67%, respectively. These results correlated with the biochemical parameters such as serum sialic acid, lung collagen hydroxyproline and uronic acid contents. Serum sialic acid level in control group was 126.8 microg/ml serum which was significantly lowered in limonene (49.3 microg/ml serum) and perillic acid treated animals (53.6 microg/ml serum). Uronic acid level was also inhibited to 56% and 39.7% in limonene and perillic acid treated animals, respectively. Histopathological studies also correlated with these above results. Administration of Carvone even at 100 micromoles/kg body wt. did not have any significant effect on the metastatic tumour growth. These results indicate that limonene and perillic acid could inhibit the metastatic progression of B16F-10 melanoma cells in mice
Raphael TJ, Kuttan G. Effect of naturally occurring monoterpenes carvone, limonene and perillic acid in the inhibition of experimental lung metastasis induced by B16F-10 melanoma cells. J Exp Clin Cancer Res. 2003 September Amala Cancer Research Centre, Amala Nagar, Kerala, India.