Efficacy of Catharanthus roseus Extract against Dengue Virus Type 2 Infection in Vitro

Catharanthus roseus, known as Madagascar periwinkle is an herbal and traditional plant used for treatment of various diseases.A study was carried out to test the cytotoxicity and antiviral effects of methanol extract from the leaves of C. roseus. The leaves of C. roseus were extracted using methanol to produce crude methanol extract. In vitro cytotoxicity test was performed to determine the concentration value of the extract causing 50% cell death (CC₅₀) using MTT assay. The antiviral activity has been confirmed by conducting foci forming unit reduction assay (FFURA) which involved post-treatment, pre-treatment and virucidal tests. Cytotoxicity test was performed on Vero cells indicates the CC₅₀ value for C. roseus extract towards Vero cells was 0.13 mg/mL. The 50% Effective Concentration, EC₅₀ of C. roseus extract was 0.025 mg/mL. Selectivity index of C. roseus extract against DENV-2 was 5.2. Three treatments were used in the antiviral test; 1) post-treatment, 2) pre-treatment, and 3) virucidal. The results revealed that the post-treatment was more effective in inhibiting viral replication compared to pre-treatment and virucidal. The results of this research showed that C. roseus extract has good potential for prospective nature-based antiviral drug.