Assessment of Immunostimulating effect of Carica papa- ya-based Immunostimulatory Complexes Against Streptococcus pneumoniae Infections

Objectives: Streptococcus pneumoniae infection is a bacterial infection responsible for one-fifth of child mortality in Africa. The aim of this study was to formulate and evaluate Carica papaya-based Immunostimulatory complexes against Streptococcus pneumoniae infections. Methods: Leaves of the plant were harvested, air-dried, pulverized and the saponin content extracted using distilled water and but anole in a Soxhlet’s apparatus. The formulation of Immunostimulatory complexes was prepared using the ethanol injection method. Acute toxicity test and Immunological assays, namely: neutrophil adhesion, carbon clearance, hem agglutinating antibody titer were conducted using healthy laboratory mice. The results were compared to standard drug (levamisole). Results: The aqueous extract and butanol fraction yielded 7.45% and 0.38% saponin. At 5000mg/ kg body weight of administered immunostimulatory complexes, no death or behavioral changes were recorded. Neutrophil adhesion showed no significant increase (20.82±4.34) as against the levamisole (20.74±3.31). The increased phagocytic index (0.089± 0.017) showed better stimulation of reticuloendothelial system when compared to both controls (distilled water = 0.032 ± 0.001; levamisole = 0.071 ± 0.001).The lower Hemagglutination antibody titre value indicates the potency of the formulated ISCOM to elicit an immune response. The ISCOM dose (250 mg/kg body weight) significantly elevated hemagglutination antibody titre (7.81±1.60). Conclusion: It can be inferred from this study that Carica papaya leaves has immunomodulatory capacity and has significant saponin yield which could potentially serve as a component of Immunostimulatory complexes formulation. Carica papaya-based Immunostimulatory complexes exhibit improved immunogenicity against Streptococcus pneumoniae infections.