Inhibitory activity of salivary glycoproteins on phytohemagglutins (PHA): Possible molecules to enhance nutritional quality of red kidney beans

Abstract

Food allergy caused by red kidney bean (Phaseolus vulgaris L.) is of serious health concern and is mainly due to its phytohemagglutinins (PHA) content. PHA can enter the circulation after oral uptake and cause IgE mediated allergy. However, studies describing enhancement of nutritional quality of red kidney beans by targeting PHA are not reported. This study was carried out to identify, PHA-inhibitory molecules present in saliva secretions. Results describe that PHA can be effectively inhibited by salivary glycoproteins. Fractionation of salivary proteins by ammonium sulphate precipitation revealed that, PHA-inhibitory proteins can be specifically precipitated at 30-60% of ammonium sulphate saturation. Gel filtration chromatography and lectin-blot analysis of 30-60% ammonium sulphate fraction suggest that only high molecular weight glycoproteins can act as potent inhibitors of PHA. In conclusion, human saliva secretions contain inhibitory glycoproteins which can be used to inhibit PHA effectively. If these glycoproteins are purified to homogeneity, can be used as potent food supplements in order to neutralize allergic potential of PHA, thus increasing the nutritional value of red kidney beans.