Comprehensive Metabolite Profiling and Enzyme Inhibitory Potential of Psidium guajava L. Hydro Alcoholic Extract: An In vitro and In Silico Approach

Psidium guajava L. is traditionally used for gastrointestinal issues, along with its use in lowering blood glucose. The present study evaluates the phytochemical composition, in vitro antioxidant potential, and antidiabetic properties of P. guajava L. hydro alcoholic extract (PGHE). TPC and TFC were quantified from PGHE. LC-ESI-QTOF-MS/MS and HPTLC were used for metabolite profiling. In vitro antioxidant, enzyme inhibition assays, and in silico molecular interactions were investigated for PGHE. The yield of extract was 6.16%. It exhibited high phenolic (147.2 ± 0.98 mg GAE/g) and flavonoid content (70 ± 1.67 mg QUE/g). HRLC-ESI-QTOF-MS/MS profiling tentatively identified 555 metabolites, with some bioactive compounds, that is, myricetin, quercetin, ellagic acid, and gallic acid. In vitro antioxidant assays showed potent radical scavenging activity, although lower than the standard antioxidant ascorbic acid. Enzyme inhibition assays revealed PGHE's α-glucosidase and α-amylase inhibition with IC₅₀ of 53.32 ± 0.25 and 79.28 ± 1.1 µg/mL, respectively. HPTLC confirmed the presence of gallic acid (0.028%), quercetin (0.093%), and ellagic acid (0.047%) with R_f values 0.592, 0.745, and 0.503. Molecular docking studies against α-amylase showed that ellagic acid had the highest binding affinity (-7.6 kcal/mol), better than the standard drug acarbose. The study links chemical diversity with functional efficacy and molecular interaction, offering a detailed in vitro and in silico validation of guava's glucose-lowering potential.