Lunasina
Mol. Nutr. Food Res. 2010; doi: 10.1002/mnfr.200900073. Lunasin, with an arginine–glycine–aspartic acid motif, causes apoptosis to L1210 leukemia cells by activation of caspase-3.
Gonzalez de Mejia E, Wang W, Dia VP
ABSTRACT
Lunasin is a novel chemopreventive peptide featuring a cell adhesion motif composed of arginine-glycine-aspartate (RGD) which has been associated to cytotoxicity to established cell lines.
The objectives of this study were to determine the effect of lunasin on the viability of L1210 leukemia cells and to understand the underlying mechanisms involved. Pure lunasin and lunasin enriched soy flour (LES) caused cytotoxicity to L1210 leukemia cells with IC(50) of 14 and 16 muM (lunasin equivalent), respectively.
Simulated gastrointestinal digestion showed that 25% of the original amount of lunasin survived 3 h of pepsin digestion and 3% of lunasin remained after sequential pepsin-pancreatin digestion for a total of 6 h. Cell cycle analysis showed that lunasin caused a dose-dependent G2 cell cycle arrest and apoptosis. Treatment of L1210 leukemia cells with 1 mg/mL of LES for 18 h led to an increase in the amount of apoptotic cells from 2 to 40%. Compared to untreated cells, treatment with 1 mg/mL LES showed a 6-fold increase on the expressions of caspases-8 and -9, and and a 12-fold increase on the expression of caspase-3. These results showed for the first time that lunasin, a naturally occurring peptide containing an RGD motif, caused apoptosis to L1210 leukemia cells through caspase-3 activation.
Commento
Sottoprodotti della soia, spesso scartati come rifiuti in seguito a processi di trasformazione, possono proteggere dalle malattie croniche come il diabete e le malattie cardiache. L’effetto protettivo sembra strettamente correlato ad una proteina contenuta nella soia, la lunasina, la quale è in grado di ridurre significativamente i livelli di molecole pro-infiammatorie, come l’interleuchina-6. L’infiammazione cronica è alla base di una vasta gamma di condizioni patologiche, associate a malattie di vario tipo (cardiovascolari, osteoporosi, Alzheimer, diabete di tipo II, artrite, neoplasie maligne). Il consumo per 5 giorni di 50 g di proteine di soia (frullato di latte di soia, chili di soia) può aumentare significativamente i livelli del peptide nel sangue e contribuire a ridurre l’infiammazione cronica. I suoi effetti anti-infiammatori sono probabilmente legati alla sequenza di amminoacidi che la caratterizza (arginino, glicina, acido aspartico), conosciuta come RGD.