Review on macrophage polarization during visceral leishmaniasis and impact of glycoprotein.

Visceral Leishmaniasis is one of the neglected vector-borne tropical disease escalating resistance against available drugs which have toxicity beyond therapeutic level leading to the requirement of alternative therapy. Macrophages, the primary cells of the immune system, being the host cells for the Leishmanial parasite undergo functional phenotypic changes based on its infected or uninfected states leading to release of specific cytokines. The M2 functional phenotype is suitable for parasite survival, while, M1 phenotype boosts the immune system leading to release of superoxide responsible for parasite clearance. Natural isolates i.e. peptides and glycoproteins isolated from various origin have been found to possess antileishmanial activities enhancing the chances to be used as a curative agent. Among them, plant glycoproteins have been found to possess immunostimulatory, antibacterial, antifungal, antiviral, anticancerous, as well as, antileishmanial activity attracting focus of researchers towards it as an alternating treating compound. This review highlights the drawbacks of existing drugs, route of development of the disease, mechanism of macrophage polarization as well as the overview of different isolated peptides and glycoproteins acting as an antileishmanial agent, having immunomodulating activity and an indication that glycoproteins can be presumed as an alternative therapy against the fatal noxious disease, if left untreated.