n-Hexane Extract of Leptastrea purpurea: Antioxidant Activity in Vitro and in Silico

Leptastrea purpurea is a species of hard coral with potential bioactive properties. This study aimed to evaluate the antioxidant properties of the n-hexane extract of L. purpurea in vitro and in silico. The in vitro antioxidants activity was assessed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, and ferric reducing antioxidant power (FRAP) assays. The extract was subjected to LC-MS/MS analysis, and three of the compounds identified; arachidonic acid, linolenic acid, and bis(2-ethylhexyl) phthalate were used for the in-silico study through ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) analysis, and molecular docking with antioxidant enzymes; superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT). Results showed that n-hexane extract of L. purpurea exhibited weak DPPH radical scavenging activity with IC50 of 189 ppm, and a relatively high ferric reducing antioxidant power with FRAP value of 62.51 ± 3.38 mgAAE/g extract. ADMET analysis showed that the three compounds exhibited good ADMET profile, with arachidonic acid fulfilling the criteria for drug-likeness. Molecular docking studies showed that the three compounds demonstrated strong binding affinity for the proteins superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT), with bis(2-ethylhexyl) phthalate exhibiting the highest binding energy of 5.0 and 5.5 kcal/mol for SOD and GPx, respectively, while arachidonic acid exhibited the highest binding energy of 5.7 kcal/mol for CAT. These findings suggest that Leptastrea purpurea possesses bioactive compounds with potential antioxidant activity.