The inhibitory effects of curcumin and catechin on lung metastasis induced
by B16F-10 melanoma cells were studied in female C57BL/6 mice. Curcumin and
catechin significantly (P < 0.001) inhibited lung tumour formation (89.3%
and 82.2%, respectively) and significantly increased the life span (143.9%
and 80.8%, respectively). Moreover, lung collagen hydroxyproline and serum
sialic acid levels were found to be significantly (P < 0.001) lower in trea
ted animals compared to the untreated controls. Curcumin and catechin treat
ment (10 mu g/ml) significantly inhibited the invasion of B16F-10 melanoma
cells across the collagen matrix of the Boyden chamber. Gelatin zymographic
analysis of the trypsin-activated B16F-10 melanoma cells sonicate revealed
that curcumin- and catechin-treated zymograms did not show any metalloprot
einase activity. Curcumin and catechin treatment did not inhibit the motili
ty of B16F-10 melanoma cells across a polycarbonate filter in vitro. These
findings suggest that curcumin and catechin inhibit the invasion of B16F-10
melanoma cells by inhibition of metalloproteinases, thereby inhibiting lun
g metastasis. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.