Phenolic Composition and Enzyme Inhibitory Activity of Sabah Stingless Bee Honey

Stingless bee honey (SBH) is recognised for its unique nutritional and bioactive profile, which varies with its botanical origin.This study evaluated the enzyme inhibitory activities targeted on cardioprotective potential of SBH from eight distinct floral sources in Sabah (Malaysia), using in vitro assays.The phenolic profile of the honey samples was also determined.Inhibition assays were conducted for angiotensin-converting enzyme (ACE), α-amylase, and pancreatic lipase to evaluate antihypertensive, antihyperglycaemic, and antihyperlipidemic effects, respectively.Anti-hypercholesterolemic potential was assessed by determining inhibitory activity against 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase and cholesterol esterase.SBH from Singapore rhododendron exhibited the highest total phenolic content (105.21mg GAE/g) and significant ACE inhibitory activity (74.62% at honey concentration of 10 mg/mL) and cholesterol esterase inhibitory activity (IC 50 of 11.80 mg/mL).In contrast, multifloral SBH had the highest total flavonoid content (35.53 mg QUE/g honey), while coconut SBH exhibited the strongest HMG-CoA reductase inhibitory activity (65.05%).Principal component analysis revealed that SBH was differentiable between botanical origins at 62.26% total variance, and phenolic compounds were the primary factor contributing to the discrimination.Caffeic acid and kaempferol were associated to the ACE inhibitory activity.These findings suggest that the enzyme inhibitory activities of SBHs related to cardioprotective potential are significantly influenced by the floral source, offering new possibilities for the targeted development of functional foods based on SBH.