ABSTRACT
The objective of this study was to check the anticancer activity of purified protease inhibitors of Lavatera cashmeriana viz LC-pi I, II, III, and IV (Lavatera cashmeriana protease inhibitors) on A549 (lung) cell. It was found that LC-pi I and II significantly inhibited the proliferation of A549 cells with IC50 value of 54 µg/ml and 38 µg/ml, respectively, whereas inhibition by LC-pi III and IV was negligible. LC-pi I and II were further found to inhibit formation of colonies in a dose-dependent manner. Also, both inhibitors were found to induce apoptosis causing chromatin condensation and DNA fragmentation, without loss of mitochondrial membrane potential. Cell cycle revealed a significant increase of subG0/G1 phase cells that are apoptotic cells. We also demonstrated a dose-dependent decrease in migration of A549 cells on cell migration assay by both inhibitors. Taken together, we demonstrate that LC-pi I and II inhibited proliferation through arresting cells before apoptosis, inducing apoptosis and inhibiting cell migration in human lung cancer cells, but the study warrants further investigation. Our results support the notion that plant protease inhibitors may have the potential to advance as chemopreventive agents.
Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , Carcinoma/drug therapy , Drug Discovery , Lung Neoplasms/drug therapy , Malvaceae/chemistry , Seeds/chemistry , Serine Proteinase Inhibitors/pharmacology , Apoptosis/drug effects , Carcinoma/pathology , Cell Line, Tumor , Cell Movement/drug effects , Cell Proliferation/drug effects , Chromatin Assembly and Disassembly/drug effects , DNA Fragmentation/drug effects , Ethnopharmacology , Humans , India , Lung Neoplasms/pathology , Medicine, Traditional , Membrane Potential, Mitochondrial/drug effects , Osmolar Concentration , Tumor Stem Cell AssayABSTRACT
BACKGROUND: Proteases play a regulatory role in a variety of pathologies including cancer, pancreatitis, thromboembolic disorders, viral infections and many others. One of the possible strategies to combat these pathologies seems to be the use of protease inhibitors. LC-pi I, II, III and IV (Lavatera cashmerian-protease inhibitors) have been found in vitro to strongly inhibit trypsin, chymotrypsin and elastase, proteases contributing to tumour invasion and metastasis, indicated possible anticancer effects. The purpose of this study was to check in vitro anticancer activity of these four inhibitors on human lung cancer cell lines. MATERIAL AND METHODS: In order to assess whether these inhibitors induced in vitro cytoxicity, SRB assay was conducted with THP-1 (leukemia), NCIH322 (lung) and Colo205, HCT-116 (colon) lines. RESULTS: LC-pi I significantly inhibited the cell proliferation of all cells tested and also LC-pi II was active in all except HCT-116. Inhibition of cell growth by LC-pi III and IV was negligible. IC50 values of LC-pi I and II for NCIH322, were less compared to other cell lines suggesting that lung cancer cells are more inhibited. CONCLUSION: These investigations might point to future preventive as well as curative solutions using plant protease inhibitors for various cancers, especially in the lung, hence warranting their further investigation.
