Antiviral Effect of Pterocarpus indicus Willd Leaves Extract Against Replication of Dengue Virus (DENV) In Vitro

Abstract

Dengue hemorrhagic fever (DHF) is major public health problem in tropical and subtropical areas of the world with lack of approved vaccines and effective antiviral therapies. With no current treatment for illness attributed to dengue virus (DENV) infection other than supportive care, therapeutic strategies that use natural extract was developed.Indonesia have many plants that potential for antiviral drµgs such as Pterocarpus indicus Willd (P. indicus). The objective of this study was to determine the effect of P. indicus to inhibit DENV replication. We used a welldifferentiated hepatocytes-derived cellular carcinoma cell line (Huh-7 it-1 cells) to determine and select antiviral activity. The toxicity effects were determined by MTT assay. Then, the suppression of DENV replication was determined by Focus assay. Dengue infected cells with DMSO were used as control. We found that crude extract (Pi), hexane (Pi.1) and ethyl acetate (Pi.2) extract showed strong inhibition with high selectivity index (SI) of 1,392; 285.36 and 168.56 respectively. Sub fraction of Pi.1 and Pi.2 still showed strong inhibition with high SI. Further sub-sub fraction of Pi.2 such as Pi.2.12 and Pi.2.12.1 still showed inhibition of DENV replication but there was reduction of SI value. The mechanism experiment of Pi.2.12, we found that Pi 2.12 more profound to inhibit in the post infection stage that entry or pre-infection. We conclude that the sub-fraction of Pi.2.12 has potential antiviral activity against DV infection in vitro. Further studies are still needed to investigate the pure compound of Pi.2.12 that inhibit and have advantages in the future as alternative for treatment of DENV infection.

The Antiviral Effect of Indonesian Medicinal Plant Extracts Against Dengue Virus In Vitro and In Silico

“…The previous study showed that methanolic leaf extracts of Hippophae rhamnoides , sea-buckthorn from a family of Elaegnaceae is a potential candidate for dengue infection management [15]. Other herbal medicines such as S. baicalensis extract showed inhibition of DENV serotypes replication in vitro by reducing DENV infectivity and replication in Vero cells [16].…”

“…Propagation of DENV and antiviral assay in this study was done the same way as in the previous study with slight modification [16]. We used 96 well-plat flat bottom well plate for cytotoxicity and antiviral assays.…”

“…In vitro cytotoxicity effect was determined by viability of Huh7it-1 cell lines in 96 well-plate after treated with natural extract [16]. After 24 hours, the cells were treated with a single dose of 20 ug/mL and was further incubated at 37 °C, 5% CO 2 .…”

“…Plates were further incubated at 37 °C for three days. Then we harvested to determine antiviral activity by counting the virus titer with focus assay with a slight modification [16]. Briefly, the mixtures of 10-fold serial dilution of viral supernatant were inoculated onto Huh7it-1 cell monolayer in triplicate wells.…”