Chikungunya virus (CHIKV) has had a major impact on human health since its resurgence in 2005 (Staples et al., 2009). It is an enveloped alphavirus of Togaviridae family with a genome size of 11.8 kb that comprises of a single-stranded, positive sense RNA (Oliviera et al., 2017). Transmission of CHIKV to humans occurs primarily via the bites of Aedes aegypti and A. albopictus mosquitoes (Powers, 2018). The disease caused by CHIKV is marked by fever, headache, rash, myalgia, fatigue and severe arthralgia (Bhakat and Soliman, 2015).

There have been extensive efforts to tackle Chikungunya disease by developing antiviral agents. However, in spite of the discovery of numerous compounds with anti-CHIKV activity, there are no drugs yet available commercially to treat the infection. Several natural products and synthetic organic molecules were reported to show promising anti-CHIKV activity. For example, harringtonine exhibits potential inhibition of CHIKV by acting at an early stage of virus replication (Kaur et al., 2012). Piperazine is able to inhibit CHIKV effectively by binding to the hydrophobic pocket of the capsid protein (Aggarwal et al., 2017). Similarly, picolinic acid also inhibits CHIKV by binding to the viral capsid protein (Sharma et al., 2016). Suramin, a sulfonated naphthylurea compound, inhibits CHIKV replication and/or viral entry into the cells (Albulescu et al., 2015). An isoquinoline derivative, berberine, with anti-CHIKV activity lowered the virus-induced activation of Mitogen-Activated Protein Kinase Signalling (Varghese et al., 2016a). Another potential molecule, andrographolide, showed CHIKV inhibition by affecting its replication (Wintachai et al., 2015). Epigallocatechin-3-gallate (EGCG), a primary component of green tea, inhibited CHIKV by acting as an entry inhibitor (Weber et al., 2015). Arbidol, an indole derivative, inhibits the virus by blocking its entry into the target cells (Delogu et al., 2011). Compounds like chryisn, apigenin, naringenin and silybin are involved in the inhibition of CHIKV replication (Pohjala et al., 2011). More recently, naphthoquinone derivatives with a sulfonamide or sulfonate group were observed to exhibit potent activity against this virus (Pacheco et al., 2022). Furthermore, tomatidine, a steroidal alkaline derivative of tomatoes, exhibited antiviral activity against CHIKV (Troost et al., 2020).

There are published reports on the use of plants for the treatment of viral diseases in traditional systems of medicine (Rajbhandari et al., 2009; Hossain, 2011; Chang et al., 2013; Cock and Van Vuuren, 2020; Kunjumon et al., 2022). Extracts from Croton mauritianus, Trigonostemon cherrieri, and Hyptis suaveolens display activity against CHIKV (Bhakat and Soliman, 2015). Recent studies have shown that extracts of Clinacanthus nutans, Hydrocotyle sibthorpioides, and Ocimum americanum hampered the release of viral progeny from CHIKV-infected cells; and the extracts of Ficus deltoidea, Gynura bicolor, H. sibthorpioides, and O. americanum prevented virus entry into the cells (Chan et al., 2021). Cassine and spectaline alkaloids from Senna spectabilis flowers displayed potential as promising anti-CHIKV drugs (Freitas et al., 2022). Sauropus androgynus (L.) Merr., is a leafy vegetable, parts of which are used in ethnomedical practices to treat fever in several Asian countries and in Ayurveda (Kanchanapooma et al., 2003; Bunawan et al., 2015; Zhang et al., 2020). Its leaves are reported to contain principles that have anti-dengue virus activity (Joshi et al., 2022). In the present study, we carried out isolation and identification of an anti-Chikungunya principle from S. androgynus and elucidated its possible mechanism action.