Immunomodulatory Effects of Hemagglutinating Lectins from Potato (solanum Tuberosum) and Garlic (allium Sativum) on Human and Murine Lymphocytes

Objective: Potato (Solanum tuberosum) and garlic (Allium sativum) are an important ubiquitously consumed dietary components and known to contain lectins, with potent and diverse biological functions. Present study aims to evaluate the mitogenicity and immunomodulatory potential of these lectins on human and murine lymphocytes. Methods: The lectin activity of raw and heat processed extracts along with purified proteins were confirmed by heamagglutination and glycoprotein binding assays. MTT assay employed to evaluate the mitogenic and cytotoxic potential. Nitric oxide and NBT assays were performed for NO and ROS induction from lymphocytes and macrophages respectively. Results: Raw and heat processed extracts of potato and garlic induced heamagglutination and demonstrated binding affinity to glycoproteins. Potato lectin was identified as pan agglutinin whereas garlic lectins, were blood group specific with differential glycan recognition. Garlic extracts and lectins (ASAs) exhibited a strong mitogenicity towards human and murine lymphocytes. The proliferation index for ASA I (70-75%) and ASA II (35-40%) are comparable to those of the reference mitogens. However, Potato extracts and lectin (STA) was non-mitogenic and found cytotoxic for both human and murine lymphocytes. Raw garlic extract showed a significant increase in ROS generation. Both potato and garlic lectins failed to induce ROS from macrophages and nitric oxide (NO) from human PBLs. Conclusions: Both potato and garlic lectins were capable of interacting with cell surface glycoproteins and it is evident that the garlic lectins have stimulatory effect whereas the potato lectin has an inhibitory effect on lymphocyte proliferation. There by, study indicates that garlic lectins are mitogenic and co-mitogenic, whereas potato lectin is non-mitogenic or anti-mitogenic in nature.