Inhibition of Naja nigricollis venom phospholipase A2 by ethylacetate extract of Solanum dasyphyllum schum and thonn leaf: an in-vitro and in-silico approach

Abstract

Introduction: Snakebite envenomation is an acute medical emergency, particularly in the tropics, and clinical treatment is through the administration of antivenom. However, given the limitations of conventional antivenoms, the plant kingdom is being explored for possible antivenom compounds. The aim of this study was to evaluate the phospholipase A inhibitory potential of ethylacetate extract of 2 Solanum dasyphyllum and to isolate the compound responsible for the antivenom activity.

Materials and Method: The leaves of S. dasyphyllum were extracted, phytochemical constituents were screened and phospholipase A₂ enzyme inhibition study was carried using standard methods. The ethylacetate extract was subjected to various chromatographic techniques to isolate the antivenom compound, and the structure was determined using HNMR and CNMR spectra. The proposed structure of the isolated compound was used for molecular docking study with cobra venom phospholipase A₂ . 

Results: The result of phospholipase A enzyme inhibition shows that different concentrations of  ethylacetate extract of S. Dasyphyllum significantly inhibited the activity of phospholipase A₂ in N. nigricollis venom. Chromatographic investigations of the extract lead to the isolation of methyl linolenate, and a strong interaction with the enzyme active site and a binding energy of -6.60 kca/mol was recorded when docked with cobra phospholipase A₂ enzyme, thereby making it a potential inhibitor of the enzyme. 

Conclusion: Conclusively, ethylacetate extract of S. dasyphyllum demonstrated a significant inhibition of phospholipids A₂ enzyme and this finding suggests that methyl linolenate may be a potential inhibitor of phospholipase A₂ and could possibly lead to the development of a drug to treat snakebites.