Allium sativum Lectin (ASA)
The immunomodulatory proteins present in garlic have recently been shown to be identical to the garlic lectins ASA I and ASA II [Clement F, Pramod SN, Venkatesh YP. In t. Immunopharmacol. 2010; 10: 316-324]. In this study, the stability of garlic lectins has been examined as a function of pH, temperature, and denaturants in relation to biological activity (hemagglutination and endocytosis).
The stability of garlic lectins in simulated gastric fluid (SGF) was evaluated by their hemagglutination activity, immunoreactivity, and integrity by SDS-PAGE. Garlic lectins were moderately stable in SGF for up to 30 min; although they retained the hemagglutination activities, the immunoreactivity with the respective rabbit antiserum immediately decreased (0.5 min) to 10-30%. ASA I retained ~ 80% hemagglutination activity in the pH range 2–12; however, ASA II retained only 40% in the 2-4 and 10-12 pH ranges. Garlic lectins exposed to 60 ° C (30 min) and pepsin (1 and 2 min) retained hemagglutination and phagocytic activity.
Urea (4 M) and Gdn.HCl (2 M) did not affect hemagglutination. The immunogenicity of garlic lectins was examined after oral feeding in BALB / c mice. A lectin-specific serum IgG response was observed in mice comparable to the oral immunogen, phytohaemagglutinin. The lectin recovered in the feces of mice administered garlic lectins showed an antigenicity identical to that of the administered proteins. The stability of garlic lectins, their ability to resist gastrointestinal passage, and their recognition by the immune system after oral feeding reinforce the reported presence of natural antibodies against garlic proteins in normal human serum.
Garlic Immunogenicity Lectins Oral administration Protease stability Thermal stability