Venomous snakebite continues to be an important public health problem in many regions of the world, particularly in rural areas lacking medical facilities; it is estimated that there are 5.4 million snakebites every year (Gutiérrez et al., 2017). In the northeastern region of Argentina, the rate of such cases associated with ophidic accidents is above the country's average rate. The genus Bothrops is responsible for 97% of the cases, with B. diporus being the most frequently reported species (Dolab et al., 2014). Snake venom is a complex mixture comprising 50–200 components which can be presented in multiple proteins and peptides iso-forms (Tasoulis and Isbister, 2017). In the Bothrops genus, the dominant family is characterized by phospholipases A2 (PLA2), metalloproteinases (SVMPs), serine proteases, and three-finger peptides (3FTXs) (Ferraz et al., 2019). These enzymes have been implicated as responsible for the local and systemic effects of the venom. Local symptoms including swelling, haemorrhage, blistering, bruising, and necrosis are mainly caused by PLA2s and 3FTXs, along with SVMPs (Lodovicho et al., 2017). Moreover, numerous experimental studies have shown that Bothrops PLA2s are involved in venom-induced inflammatory responses and other toxic or pharmacologic effects including anticoagulant and haemolytic effects (Ferraz et al., 2019; Ricciardi Verrastro et al., 2018; Tasoulis and Isbister, 2017).

The administration of heterologous antivenom serum is the standardized treatment for venom intoxication; however, secondary effects could be significant (Gutiérrez et al., 2017). In addition to this, the anti-venom serum has low effectiveness on the local effects produced by the venom immediately after the bite; it also requires special storage conditions and qualified personnel for its application (Puzari et al., 2022).

There are several studies concerning plants with alexiteric properties, focusing on the ability to alleviate symptoms such as pain, bleeding, inflammation, infection, or even poisoning (Amui et al., 2011; Esmeraldino et al., 2005; Guimaraes et al., 2014; Ricciardi Verrastro et al., 2018; Vale et al., 2008). Reports on the indigenous medicine of Central and South America contain references to the use of various plant species of the Lauraceae family, including the genus Nectandra and Ocotea, in the therapy for infections of the genitourinary, gastrointestinal, and broncho-pulmonary systems (Giovannini and Howes, 2017). In addition, they have been used in the treatment of snakebite, toothache, rheumatism, and other inflammatory disorders (González Torres, 1981; Grecco et al., 2016; Horák, 2014; Houghton and Osibogun, 1993; Macías-Villamizar et al., 2015). Particularly, Nectandra angustifolia (Schrad.) Nees & Mart., popularly called “yellow laurel”, “river laurel” or “aju'y hû”, is a native species in South America, predominantly in northeastern Argentina, Brazil, and Paraguay. The ethnomedicinal use of this plant is well known in folk medicine and the first written reports can be traced to the Jesuit missions in the 16th century, describing its use by aboriginal tribes (guaraníes northeastern Argentina) as a digestive, anti-ulcerous, pain treatment and to treat snakebites (Barboza et al., 2009; González Torres, 1981; Horák, 2014). Plant extracts constitute a complex mixture of compounds with a variety of pharmacological activities. A wide group of compounds have been reported as effective neutralizing agents against different Bothrops species e.i, saponins and terpenoids against B. jararaca and B. jararacussu (Liaqat et al., 2022); alkaloids against B. pauloenssis (Torres et al., 2011, Torres et al., 2011). Among these chemical species, polyphenolic compounds have been extensively studied because of their biological benefits (Amui et al., 2011; Grecco et al., 2016; Puzari et al., 2022). Flavonoids involve a group of natural compounds with variable phenolic structures and many biochemical properties, among which their antioxidant activity is the best described. There are some reports concerning the alexiteric properties of flavonoids against Bothrops species (Macías-Villamizar et al., 2015; Preciado et al., 2018; Puzari et al., 2022), and specifically against B. diporus (Ricciardi Verrastro et al., 2018). Their anti-inflammatory effects are also of particular interest since they might be responsible for the local effect of plant extracts in snakebites treatment (Truiti et al., 2006). Among flavonoids, quercetin and its derivates have been indicated as compounds with several biological activities, including anti-inflammatory (Ferrini et al., 2021; Grecco et al., 2016) and alexiteric effects, among many others (Khan et al., 2020; Kumar et al., 2017; Preciado et al., 2018; Rashid et al., 2019; Ricciardi Verrastro et al., 2018).

As both snake venom and plant extracts are complex mixtures of different compounds, in vitro and in vivo results could be difficult to interpret to elucidate the mechanism of action of the bioactive compounds. Molecular modelling techniques, including docking and molecular dynamics (MD) simulations, represent an interesting strategy to study the possible mechanisms involved in the biological effects, including alexiteric properties of natural compounds against different components of venom (Cotrim et al., 2011; Jahan et al., 2022; Kumar et al., 2017; Preciado et al., 2018).

In this study, the inhibitory effect of N. angustifolia extracts on Bothrops diporus venoms by in vitro tests was investigated. The chemical identity of an enriched fraction obtained by bio-guided fractionation was established by UPLC-MS/MS analysis. Docking combined with MD simulations and charge density analysis were carried out to predict how the flavonoids in the extract's most active fraction interact with residues from the PLA2 binding crevice. These findings, in turn, revealed some clues about the possible inhibition mechanisms of the principles present in N. angustifolia extracts.