Phytochemical Profiling, Bioactivity Evaluation and In Silico Insights Onto <i>Goniothalamus simonsii</i> Hook. f. Thoms.: An Endangered Medicinal Plant

Goniothalamus simonsii Hook. f. Thoms., an endangered medicinal plant is endemic to the state of Meghalaya, India. Its wide use in traditional medicine in Meghalaya for treating gastrointestinal complications, throat irritation and typhoid fever, is not matched by scientific reports on its pharmacological attributes. The present investigation evaluated the phytochemical constituents by GC-MS analysis; while bioactivities including antioxidant, antimicrobial and cytotoxicity were assessed by DPPH, agar-well diffusion and MTT methods, respectively. The leaf extract showed elevated content of phenolics (154.76 ± 7.98 mg GAE/g) and flavonoids (55.91 ± 3.05 mg QE/g). GC-MS analysis identified compounds included cis-vaccenic acid, kavain, 3-methoxy-2-(quinoxalin-6-yliminomethyl), spathulenol, aziridine, stigmasterol, n-hexadecanoic acid, cholest-4-en-3-one, coniferyl alcohol and so forth. Leaf extract displayed IC₅₀ value of 437.38 ± 13.11 µg/mL in the DPPH assay. The extracts displayed antimicrobial activity (13.21-22.63 mm) against a broad spectrum of bacteria, with minimum inhibitory concentration (MIC) values ranging > 1000-58.59 µg/mL. The antiproliferative effect was observed against colon cancer cell line (HT-29) with IC₅₀ value of 9.8 ± 7.84 µg/mL. Docking results demonstrated that stigmasterol exhibited the highest binding affinity for target protein CDK2, with docking score of -8.9 kcal/mol. These findings serve as a catalyst for additional research on G. simonsii as a prospective bioresource for bioactive compounds in future phytotherapeutics.