Research Projects

Rationale of the Research: Visceral Leishmaniasis (VL), caused by the protozoan Leishmania donovani, is a significant global health concern, with 30000 new cases per year and 1 billion people are at risk living in the endemic regions of VL. Current treatment options are limited, expensive, and associated with toxic side effects and the emergence of drug resistance. Thus, there is an urgent need to explore alternative therapeutic agents. The seeds of Carica papaya are rich in bioactive compounds and have been traditionally used for treating various parasitic infections. As per literature fatty acid derivatives possess antiprotozoal properties, particularly against Leishmania infantum and Leishmania major. The seeds of carica papaya are rich in fatty acids such as oleic acid, palmitic and stearic acid which are reported to have anti-leishmanial activity. Hence, This study seeks to investigate the efficacy of bioactive compounds isolated from C. papaya seed extract against L. donovani, providing a novel avenue for the development of safer and more effective treatments. Scientific Objectives: This study aims to isolate and characterize bioactive compounds from Carica papaya seeds and evaluate their in vitro anti-leishmanial activity against the promastigote and amastigote forms of Leishmania donovani. The research will further elucidate the mode of action of the most potent compounds using biochemical and molecular assays and assess their in vivo anti-leishmanial efficacy in a BALB/c mice model. Hypothesis/Model to be Tested: We hypothesize that C. papaya seeds contain fatty acids like palmitic, stearic, and oleic acids, along with other bioactives, exhibiting potent immunostimulatory and anti-leishmanial activities with minimal cytotoxicity. These compounds may directly target L. donovani metabolism or enhance anti-leishmanial immune responses.. Main Experiments to be Carried Out: Bioactive compounds will be extracted and characterized using NMR, FTIR, and LC-MS analysis. In vitro anti-leishmanial activity against L. donovani promastigotes and amastigotes will be studied by alamar Blue assay and Giemsa staining, respectively. Cytotoxicity in macrophages will be evaluated to determine the therapeutic index. Mechanistic studies will assess NO generation, arginase activity, and mRNA expression of inflammatory markers and iNOS-2 in L. donovani-infected macrophages. Cytokine release by ELISA and MAPK protein expression by Western blotting will also be analyzed. In vivo anti-leishmanial activity of bioactive compounds will be evaluated in BALB/c mice by assessing parasite loads in the spleen and liver. Immunomodulatory effects will be studied via Th1/Th2 cytokine responses in splenocytes using ELISA and RT-PCR. Significance to the Field: This study explores C. papaya seed bioactives for anti-leishmanial activity, aiming to develop affordable, natural, and less toxic therapeutic alternatives to current treatments.