Investigating of the Phytoconstituents, Anti-α-Glucosidase, Antilipase, Anti-α-Amylase, and DPPH Radical Scavenging Activities of Extracts From Eriobotrya japonica.

Recent research reported inhibitory effects of Eriobotrya japonica leaf extracts on DPPH free radicals and α-amylase, α-glucosidase, and lipase enzymes. These enzymes were linked to the etiology of diabetes mellitus, obesity, and oxidative stress. The current study is aimed at determining the phytocontents of E. japonica aqueous extract leaves and exploring their potential antioxidant, anti-α-amylase, anti-α-glucosidase, and antilipase activity using reference phytochemical and biochemical assays. The phytochemical tests on the E. japonica aqueous extract confirmed the presence of alkaloids, glycosides, tannins, saponins, phytosteroids, carbohydrates, and phenols. The total phenol and tannin contents of the E. japonica aqueous extract were 21.64 ± 0.89 mg of GAE/g and 1.72 ± 1 mg of CAE/g, respectively. E. japonica aqueous extract had inhibitory effects on DPPH free radicals (IC₅₀ of 7.7 ± 3.11 μg/mL) and α-amylase (IC₅₀ = 141 ± 0.35 μg/mL) compared with Trolox and acarbose (6.3 ± 0.12 and 28.18 ± 1.22 μg/mL, respectively). Moreover, E. japonica aqueous extract inhibited α-glucosidase (IC₅₀ = 39.81 ± 0.74 vs. 37.15 ± 0.33 μg/mL inhibition by acarbose) and lipase (IC₅₀ = 316.2 ± 0.87 vs. 12.3 ± 0.33 μg/mL inhibition by orlistat). In conclusion, the current results suggest that E. japonica aqueous extract possesses strong antioxidant, anti-α-glucosidase, anti-α-amylase, and antilipase activities with potential applications in the treatment and prevention of obesity, diabetes mellitus, and oxidative stress.