Identification of Bioactive Compounds and Analysis of Inhibitory Potential of the Digestive Enzymes from Syzygium sp. Extracts

Diabetes and obesity represent major public health problems worldwide. High cost of medicines and drug treatments propose the research for less expensive alternatives, such as enzymatic inhibitors present in medicinal plants from natural sources. An example of such medicinal plant is the jambolan Syzygium sp., which is referred to be hypoglycemic and efficient in weight loss. With this in mind, we identified the bioactive compounds from Syzygium sp. commercial teas and evaluated the inhibitory potential and the antioxidant activity of digestive enzymes from a simulated gastric fluid. Syzygium sp. samples showed low percentages of enzymatic inhibition at 1 : 200 dilution. Antioxidant activity was significant, although it was not expressive of the contents of total phenolic compounds, tannins, flavonoids, flavones, and alkaloids. Maldi-Tof spectroscopy suggested the presence of luteolin in Syzygium sp. samples. Molecular docking predicted that luteolin binds at the α-amylase catalytic site in a similar manner as acarbose, the carbohydrate inhibitor from the enzyme crystallographic structure. The phytochemical content and biological activity were distinct among samples from commercial teas. Thus, additional studies should be conducted to elucidate efficacy and safety of Syzygium sp. extracts, especially in vivo experiments. Syzygium sp. might be in the near future recommended as a medicinal plant in low cost diabetes and obesity treatments.