Antioxidant and Anti-Inflammatory Activities from Optimum Formula of Spatholobus littoralis Hassk. and Sauropus androgynus L.: In Vitro and In Silico Studies

This study aimed to optimize a formulation of Spatholobus littoralis Hassk. stems and Sauropus androgynus L. leaves using Simple Lattice Design (SLD). In this context, the response variable was DPPH (2,2-Diphenyl-1-picrylhydrazyl) antioxidant activity, while the optimum extract concentration of the two plants served as the experimental factor. Subsequently, the optimum formula was investigated for its in vitro anti-inflammatory activity against COX-2 (cyclooxygenase-2) and through in silico study. Molecular docking on the COX-2 receptor (PDB ID: 5IKQ) from the secondary metabolite profile was validated for the optimum formula. The formulation recommended by SLD comprised a 1:1 mixture of 70% ethanol extract of S. littoralis Hassk. stems and S. androgynus L. leaves. This optimum formula had an IC50 value of 108.70 µg/mL for the DPPH antioxidant with a synergistic effect due to the production of higher COX-2 inhibitory activity (73.05 ± 2.36%) than the single extract at 100 µg/mL. Daidzein (−8.514 kcal/mol), (10E,12Z)-9-Hydroperoxy-10,12-octadecadienoic acid (−7.604 kcal/mol), arteannuic acid (−7.114 kcal/mol), L-Proline,4-hydroxy-5-oxo-4-(tetrahydro-2,3,4-trihydroxy-2-furanyl)- (−6.480 kcal/mol), and Androst-2-en-17-amine,4,4-dimethyl-N-(2-phenylethyl)-, (5.alpha.)- (−5.440 kcal/mol) were the five compounds from the 70% ethanol extract of S. littoralis Hassk. stems and S. androgynus L. leaves that strongly bound 5IKQ. These compounds were obtained from five groups of compounds, namely flavonoids, fatty acids, terpenoids, amino acid derivatives, and amine derivatives. The formulation of S. littoralis Hassk. and S. androgynus L. extract has potential as an antioxidant and anti-inflammatory agent.