The Efficacy of Bio-synthesized Silver Nanoparticles with Carica papaya Extract against Plasmodium berghei Infected Mice

Background: The evolution of antimalarial drug resistance increases malaria's burden and is a recurring concern in the global fight against malaria. Medicinal herbs have played an important role in the treatment of malaria and have been advised in reducing Plasmodium parasite resistance to standard antimalarial medications. Papaya contains antimalarial bioactive chemicals. Medicinal plants have been found to have some limitations such as poor dosage regimens, determination of active phytochemical components and specific delivery issues at the right time without causing serious damage to the concerned tissue and organs in the body system. Using nanotechnology and nanomedicine for malaria treatment can overcome these limitations. 
Objective: This study was aimed to assess the potential of Carica papaya leaf extract with silver nanoparticles against Plasmodium berghei-infected mice. 
Materials and Methods: Fresh Carica papaya leaves were collected in Oke-Arade, Ogbomoso, active contents of leaves were extracted and biosynthesized silver nanoparticles were passed into the infected experimental mice. For the investigation, 40 mice were utilized, and their parasitemia level, haematological and histological parameters determined to assess safety effect of the nanoparticle as well as efficacy of the extract.  Kidney and liver samples were analyzed for haematological, parasitological, and histological parameters. 
Results: On days 3 and 5, Ag-NPs at 25mg/Kg and 50mg/Kg cleared malaria parasitemia better than plant extracts at 100mg/Kg and 200mg/Kg (p<0.05). The mice's weight loss improved on day 5 (p>0.05), as did PCV (p<0.05). 
Conclusion: The Ag-NPs synthesized with C. papaya showed antimalarial activity against Plasmodium berghei as more of the infected red blood cells were cleared indicating a decrease in parasitemia coupled with the reduction of the malaria parasite density across the experimental periods. This process of synthesizing Ag-NPs with the extract is simple and cost effective, thereby it's a promising antimalarial alternative.