Evaluation of cytotoxicity and antiviral activity of Kyllinga nemoralis leaves and stems methanolic extract

Abstract

This present study aimed to investigate the potential stems and leaves methanolic extract of Kyllinga nemoralis as an antiviral agent against Herpes Simplex Virus Type 1 (HSV-1). The leaves and stems of K. nemoralis methanolic extract were assessed in the cytotoxicity test using the MTT assays. The plaque reduction assay was evaluated in the post-treatment assay, pre-treatment assay, virucidal assay, time-addition test, and time-removal test. Cytotoxicity screening of stems and leaves of K. nemoralis against Vero cells shows that the cytotoxicity concentration of 50% of cell viability (CC50) values was 0.75 mg/mL, which indicates that K. nemoralis is non-cytotoxic and safe. The antiviral assay provides a Selective Index (SI) value (CC50/EC50) to determine the good SI for antiviral activity. In post-treatment, the SI value for this extract against HSV-1 was 8.33. In pre-treatment, the SI value for this extract was 21.43. In the virucidal test, the SI value for this extract was 24.19 mg/mL. In the time addition assay, the plaque inhibition reached 43% when the extract was added at 2 h.p.i, and it dropped to 15% at 10 h.p.i. In the time removal assay, the plaque inhibition reached 50% after the extract was removed at 2 h.p.i., and it increased to 87% at 24 h.p.i. This study showed that K. nemoralis has potential as a drug used to fight herpes infections.