Inhibitory Activities of Methanolic Extracts of Carica papaya, Mentha piperita and Citrullus colocynthis Against Dengue Viruses-2 viability

Abstract

This study targets the methanolic extracts from the leaves of Carica papaya (Papaya) and Mentha piperita (Mint), as well as the leaves and fruit extracts of Citrullus colocynthis (Tumma plant) for their antiviral activity against dengue virus type 2 (DENV-2) in vitro, utilizing the HepG2 cell line. The antiviral activity of the plant extracts mentioned above was assessed through a plaque formation assay on the HepG2 cell line. The methanolic extracts from the leaves of C. papaya and M. piperita demonstrated lower toxicity than the fruit extract of C. colocynthis. Notably, the fruit extract of C. colocynthis maintained the normal morphology of DENV-2- infected HepG2 cells with minimal cell mortality. The cell survival rates were found to be 80-100% for 0.30mg/ml and 0.20mg/ml of C. papaya and M. piperita leaves extracts and 0.08mg/ml of C. colocynthis fruit extract. The most effective inhibition of DENV-2 was attributed to the fruit extract of C. colocynthis, exhibiting 46.55% inhibition at 0.08mg/ml. In comparison, M. Piperita and C. papaya leaf extracts demonstrated 24.14% and 23.33% inhibition against 0.20mg/ml and 0.30mg/ml, respectively. The plaque forming unit (PFU/ml) at the highest concentration ensuring 100% cell survival was calculated as 1.5×106, 1.4×106, and 1.0×106 PFU/ml for C. papaya and M. piperita leaves extracts and C. colocynthis fruit extract, respectively. The study infers that the methanolic fruit extract of C. colocynthis exhibits a high potential for inhibiting DENV-2 compared to the other two extracts.