Lunasin

Lunasin is a 43-amino acid polypeptide discovered by a team of Japanese scientists in 1987. It was originally isolated, purified, and sequenced from soybean seed. Although no name has been given, it was described as an amino acid sequence of a soybean (Glycine max) seed polypeptide having a poly (L-aspartic acid) structure at the carboxyl terminus by its discoverers. Subsequent research by Dr. Alfredo F. Galvez at the University of California- Berkeley, identified the peptide as a subunit of the cotyledon-specific 2S albumin. Its amino acid sequence is SKWQHQQDSCRKQKQGVNLTPCEKHIMEKIQGRGDDDDDDDDD. Due to the health benefits of soy in which it was extracted, Dr. Galvez and associates named it as Lunasin from the Filipino word “lunas” which means ”cure”. Aside from soy as its main source, it is also found in barley, wheat, amaranth, black nightshade, pinto bean, corn and rye.

Discovery of biological activity

Lunasin’s biological and cancer-preventive activity was discovered by a Filipino doctor during his post-doctoral

Galvez was the first to identify the peptide’s ability to prevent the transformation of normal cells into cancerous tumors in cell culture. Animal studies validated the findings when lunasin significantly reduced the tumor incidence in mice skin exposed to chemical carcinogens. In the original 2001 study that discovered and named lunasin, the authors wrote that their results "suggest a mechanism whereby lunasin selectively induces apoptosis, mostly in cells undergoing transformation, by preventing histone acetylation"—the protein could cause cell death in developing cancer cells, while not affecting regular cells, in mice. This led to the speculation that lunasin might explain the numerous epidemiological associations between consumption of soy products and the low cancer incidence observed in Asian populations. In 2003 a study conducted by Bio-Rad Laboratories showed that the protein also did not affect immortalized and established cancer