Goniothalamin Is Effective In Vitro Against Acyclovir-Resistant Herpes Simplex Virus Type-1

A major problem faced in treatment of virus infection is the presence of (Human Herpes virus type 1, HHV-1) antiviral drug resistant viruses i.e. acyclovir. Thus, search for drugs with the capability to encounter acyclovir-resistant HHV-1 is urgently needed. This study is aimed to configure the goniothalamin (GTN) isolated from Goniothalamus umbrosus followed by identifying the in vitro ability to inhibit acyclovir-resistant HHV-1 mutants. Crystals developed following extraction from the root and bark of G. umbrosus was confirmed by GC-MS, FTIR and NMR as goniothalamin. The J coupling peak calculation confirms that the active compound was in a cis-configuration. Prior to the antiviral activity determination, the cytotoxic concentration of GTN that killed 50% of the vero cell population (CC50) was determined with a CC50 value of 8.747 mu g/mL. GTN concentration lower than the CC50 value was used in the determination of antiviral activity. Eleven HHV-1 mutant isolates were tested in the post-treatment assay to determine the antiviral activity. The effective concentration that reduces 50% of viral plaque formation (EC50) ranged from 0.47 mu g/mL (2.35 mu M) to 1.42 mu g/mL (6.42 mu M). The selective index (SI) ratio that determines the effectiveness of antiviral activity to cytotoxicity is between 6 to 17 which indicates that GTN has good potential to act as an antiviral agent. In conclusion, GTN in cis configuration has the ability to inhibit acyclovir-resistant mutant isolates. This potential is important to encounter the current problem in transmission of ACV-resistant mutants especially with thymidin kinase or DNA polymerase mutations.