Cell Culture and Molecular Docking Analysis to Determine the Antiviral Activity of Folklore Medicinal Plants Against Chikungunya Virus.

Introduction: Chikungunya Virus (CHIKV), a mosquito-transmitted pathogen, poses a significant global health threat owing to its widespread prevalence and high morbidity. There are no approved vaccines or antivirals for prevention or treatment. Screening of folklore medicinal plants has emerged as a promising approach to finding novel therapeutics to combat pathogens. Hence, this study aimed to evaluate the anti-chikungunya potential of folklore medicinal plants and their phytochemicals.

Methods: Maximum non-toxic concentrations (MNTD) of the extracts to Vero cells were determined by the cytotoxicity assay. A Focus-Forming Unit (FFU) assay was used to assess the antiviral activity of the extracts (at MNTD) against CHIKV in Vero cells under pre-, co-, and post-treatment conditions. GC-MS was used to detect the phytochemicals of the extracts, and Schrodinger (Maestro) software was employed for their molecular docking against the target protein of CHIKV.

Results: Azadirachta indica exhibited anti-CHIKV activity during pre- and post-treatment, decreasing the virus titer from 8.145 to 7.998 and 8.361 to 8.040 mean log10 FFU/ml, respectively. Calendula officinalis and Piper retrofractum exhibited anti-CHIKV activity only during post-treatment (8.361 to 8.135, 8.361 to 8.075). Moreover, molecular docking studies of phytochemicals detected in GCMS analysis of all the extracts revealed that many phytochemicals (especially F3, F5, F6, and A1) could bind to the non-structural protein (nSP2) target of CHIKV and suppress the viral replication.

Conclusion: The screened plants showed the ability to inhibit CHIKV infection and replication and hold potential for further investigation in developing treatments for Chikungunya.