Antioxidant and Antidiabetic Activity of the Bulb Extract of Crinum amoenum Roxb. ex Ker Gawl: An Integrated In
Prabhat Kumar Jha1,2, Kalsoom Khan3, Asad Abbas4
1Department of Pharmacy, Madan Bhandari Academy of Health Sciences, Hetauda 44100, Nepal.
Abstract:
Crinum amoenum Roxb. ex Ker Gawl. (C. amoenum) is traditionally used in Nepal, but its antidiabetic potential remains insufficiently validated. This study characterized the 80% (v/v) ethanol bulb extract of C. amoenum and evaluated its antioxidant, α-amylase inhibitory, hypoglycemic, molecular docking, molecular dynamics (MD) simulation, and ADMET profiles. The ethanolic bulb extract was evaluated through phytochemical screening, thin-layer chromatography, total phenolic content (TPC), total flavonoid content (TFC) estimation, LC-MS analysis, antioxidant assays, α-amylase inhibition assays, acute toxicity testing, and hypoglycemic/oral glucose tolerance test (OGTT) studies in Wistar rats. Lycorine, pratorinine, and palmatine were docked against α-amylase (PDB ID: 5U3A) and GLP-1R (PDB ID: 6GB1), followed by 200 ns MD simulations and ADMET prediction. Qualitative analysis of the extract was positive for flavonoids, phenolic compounds, tannins, saponins, alkaloids, and carbohydrates, and a positive Salkowski reaction indicated the presence of constituents occurring in glycosidic form. The TPC was 173.38 ± 1.22 mg GAE/g, and the TFC was 314.58 ± 0.09 mg QE/g. LC-MS tentatively annotated lycorine, pratorinine, and palmatine based on retention time, m/z values in positive-mode electrospray ionization, and comparison with previously reported spectral information. The extract showed DPPH scavenging activity (IC50: 90.98 μg/mL) and strong α-amylase inhibition (IC50: 49.31 μg/mL) compared with acarbose (IC50: 51.51 μg/mL). No deaths were observed following oral administration at 5000 mg/kg to rats. The 500 mg/kg dose produced the greatest hypoglycemic response, reducing blood glucose by 35.78% at 120 min in non-diabetic Wistar rats and by 19.21% at 60 min in glucose-loaded rats. Among all the compounds tested, pratorinine demonstrated the highest docking affinity with α-amylase (-8.2 kcal/mol; ASP300) and GLP-1R (-7.0 kcal/mol; GLY132). MD simulation supported greater stability of the α-amylase complex, and ADMET prediction identified pratorinine as a comparatively favorable predicted lead candidate (LD50: 1000 mg/kg; Class 4 toxicity category). Pratorinine was identified as the most promising in silico antidiabetic candidate from the C. amoenum extract, primarily due to stable α-amylase interactions and favorable ADMET properties.
