Inhibitory effect of <i>Siphonochilus aethiopicus</i> (Schweinf.) B.L. Burtt on prostaglandin/leukotrienes synthesis, and <i>in silico</i> analysis of HPLC-identified compounds

Purpose: To investigate the lipoxygenase (LOX) and cyclooxygenase (COX) inhibitory effects of Siphonochilus aethiopicus (Schweinf) B.L. Burtt (Zingiberaceae) rhizome, and to undertake in silico studies of identified compounds. Methods: The ground rhizome powder of S. aethiopicus was extracted sequentially using n-hexane, ethyl acetate and methanol. Inhibitory effects on cyclooxygenase 2 (Cox-2) and lipoxygenase (LOX) were determined using a Cox-2 test kit and spectrophotometric analysis, respectively, with Ibuprofen and quercetin as standards. High-performance liquid chromatography with diode array detection (HPLCDAD) was utilized for qualitative analysis and identification of bioactive compounds. Molecular docking was carried out using Maestro software. Ligands were docked with PDB ID: 4PH9 and 1JNQ for Cox-2 (Mus musculus) and LOX-3 (Glycine max), respectively. Results: Ethyl acetate extract showed the highest Cox-2 inhibitory activity (66.62 ± 6.50 %, IC50 = 0.241 ± 0.02 mg/mL) and LOX inhibitory activity (65.87 ± 7.75 %, IC50 = 0.190 ± 0.00 mg/mL) at 1 mg/mL. Polyphenolic compounds identified via HPLC-DAD were tannic acid, gallic acid, naringenin/caffeic acid, and quercetin. Molecular docking revealed hydrogen bonding and π-π interactions between the ligandsand active sites of enzymes. Conclusion: S. aethiopicus inhibits Cox-2 and LOX enzymes. The presence of quercetin and caffeic acid in S. aethiopicus rhizome highlights its potential as a therapeutic agent in inflammatory diseases and warrants further investigation for drug development.