Phytochemistry, cytotoxicity and antiviral activity of Catharanthus roseus

Catharanthus roseus is generally used to treat many diseases in folklore remedies. The present study is aimed at determining phytochemical constituents, cytotoxicity and antiviral activities for crude extract of the plant.

The whole plant of C. roseus was extracted using methanol extraction method. Phytochemical qualitative screening was carried out for C. roseus extract according to standard procedures used to test for the presence of alkaloid, saponin, terpenoid and steroid. Cytotoxicity was assessed using 3-(4,5-dimethylthiazol-2,5-diphenyltetrazolium bromide (MTT) assay. Plaque reduction assays were carried out to evaluate the antiviral activity of C. roseus extract against herpes simplex virus type 1 (HSV-1). These include post-treatment, pre-treatment and virucidal assays.

C. roseus extract contain secondary metabolites such as alkaloid, saponin and terpenoid but does not contain steroid. Cytotoxicity screening against Vero cells using MTT assay showed that the CC₅₀ values for crude extract of C. roseus was 0.5 mg/mL. The extract prepared from C. roseus possesses phytochemical compound that was non-cytotoxic to the cell with potential antiviral activity. Plaque reduction assays against herpes simplex virus type 1 (HSV-1) showed that the selective indices (SI = CC₅₀ / EC₅₀) of C. roseus extract in post-treatment, pre-treatment and virucidal assays were 36, 20 and 4.7 respectively. The results revealed that the extract prepared from C. roseus possesses phytochemical compound that was non-cytotoxic to the cell with potential antiviral activity.

This study showed that C. roseus extract has promising potential to be explored as anti-HSV-1 agent regardless of the mode of treatment.