Investigation of biological interactions in Euphorbia rigida extract using molecular docking

In this study, the antioxidant activity, phenolic content, and antimicrobial properties of Euphorbia rigida aerial parts methanol extract were investigated. The extract demonstrated significant antioxidant activity with a DPPH radical scavenging activity IC50 value of 919.46 µg/mL. The iron chelating activity was characterised by an IC50 value of 4.24 mg/mL, with total phenolic content measured at 11.96 mg GAE/g extract DW and total flavonoid content at 26.83 mg QE/g extract DW. The antimicrobial evaluation compared the E. rigida aerial parts methanol extract to standard drugs such as Ampicillin, Chloramphenicol, and Ketoconazole. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values ranged from 12.5 mg/mL to >50 mg/mL. The extract exhibited strong antibacterial effects with MIC and MBC values of 25 mg/mL for E. coli and 12.5 mg/mL for B. cereus. Additionally, while some antifungal activity was observed against C. albicans, it was less effective than Ketoconazole. GG-MS analysis identified Guanosine as the most abundant compound in the extract, accounting for 35.78% of the total area. Molecular docking studies with phosphatidylinositol-specific phospholipase C showed that Guanosine had the strongest binding affinity with a binding energy of -5.0 kcal/mol, forming multiple interactions. Neophytadiene and Dihydroxyacetone exhibited weaker binding affinities and fewer interactions. Toxicity assessments indicated low toxicity for the extract's components, with LD50 values of 2200 mg/kg for Dihydroxyacetone, 13 mg/kg for Guanosine, and 500 mg/kg for Neophytadiene. In summary, the study sought to elucidate the antimicrobial potential and biological interactions of E. rigida aerial parts methanol extract.