Inhibition of B16F-10 Melanoma–Induced Lung Metastasis in C57BL/6 Mice by Aerva lanata via Induction of Apoptosis

Abstract

In this study, the antimetastatic potential of the ethanolic extract of Aerva lanata was evaluated using the B16F-10 melanoma-induced lung metastasis model. Metastasis was induced in C57BL/6 mice by injecting highly metastatic B16F-10 melanoma cells through the lateral tail vein. Simultaneous treatment with A lanata inhibited tumor nodule formation in the lungs (70.53%), and there was a 65.3% increase in the survival rate of metastatic tumor-bearing animals. These results correlated with biochemical parameters such as lung collagen hydroxyproline, hexosamine, and uronic acid contents; serum sialic acid and γ-glutamyl transpeptidase levels; and histopathological analysis. In vitro studies using B16F-10 cells showed that A lanata inhibited migration of tumor cells, cell invasion through type-I collagen-coated polycarbonate filter and activation of matrix metalloproteinases. Treatment with A lanata induced apoptotic response, characterized by apoptotic morphology, a typical ladder of DNA fragmentation, and detection of 3' hydroxyl ends in DNA by TUNEL assay. There was an increase in the percentage of cells in the sub-G0/G1 phase indicating cell cycle arrest. A lanata treatment resulted in downregulation of bcl-2 and cyclin-D1 expression and upregulation of p53, bax, caspase-9, caspase-3, p21, and p27 gene expression in B16F-10 cells. Proinflammatory cytokine production and gene expression were also found to be downregulated in A lanata-treated cells.