Antimetabolic Syndrome Effects of a Flavonoid-Rich Extract from the Leaves of Newbouldia laevis: in Vitro and in Silico Investigations

Abstract

     This study evaluates the antimetabolic syndrome potential of a flavonoid-rich extract from the leaves of Newbouldia laevis (FRENL) using in vitro antioxidant and enzyme inhibition assays, complemented by GC-MS profiling and in silico molecular docking. The antioxidant activity of FRENL was evaluated using the ferric reducing antioxidant power (FRAP) and 2,2-di-phenyl-1-picrylhydrazyl (DPPH) assays, while enzyme inhibition assays targeted alpha-amylase, alpha-glucosidase, pancreatic lipase, and angiotensin-converting enzyme (ACE). FRENL demonstrated strong antioxidant activity with IC50 values of 191.60 µg/ml for FRAP and 199.30 µg/ml for DPPH. Enzyme inhibition assays revealed concentration-dependent inhibition of the key metabolic enzymes: alpha-amylase (IC₅₀ = 90.46 µg/ml), alpha-glucosidase (IC₅₀ = 65.47 µg/ml), pancreatic lipase (IC₅₀ = 109.20 µg/ml), and ACE (IC₅₀ = 110.00 µg/ml), suggesting potential anti-diabetic, anti-obesity, and anti-hypertensive effects. GC-MS analysis identified major phytochemicals, including kaempferol, apigenin, phytol, and quercetin, which are known for their bioactivity. Molecular docking studies showed strong binding affinities of these compounds to the active sites of the target enzymes. Notably, kaempferol showed the best binding energies against alpha-amylase (-8.4 kcal/mol), alpha-glucosidase (-7.8 kcal/mol), pancreatic lipase (-8.7 kcal/mol), and quercetin against ACE (-7.5 kcal/mol), forming stable hydrogen bonds and hydrophobic interactions with key catalytic residues. These findings support the traditional use of Newbouldia laevis in managing metabolic disorders and suggest that its flavonoid-rich extract contains bioactive compounds with multi-target potential. Further in vivo and clinical studies are recommended to validate these effects and explore therapeutic applications in metabolic syndrome management.