Phenolic Profile, Antioxidant, Antidiabetic, and Antigout Potential of Stem Extracts of Four Sweet Cherry Cultivars

In order to highlight the activities of bioactive compounds present in the stem of sweet cherries, four different cultivars (Van, Burlat, Napoleon, and Cœur pigeon) were collected in Sefrou city in Morocco and were studied. Several assays were performed for this purpose, such as the quantification of phenolic compounds (TPC, TFC, and CTC) and the evaluation of the antioxidant activity using DPPH, ABTS, and FRAP assays. The phenolic profile of each extract was characterized by UHPLC-DAD/MS analysis. The antidiabetic (α-amylase inhibition) and antigout (xanthine oxidase inhibition) activities were also investigated. The results showed high levels of phenolic compounds, with the values of 340 ± 12.06, 244 ± 10.20, 232 ± 5.07, and 19 ± 3.10 mg gallic acid equivalent/g extract for the cultivars Napoleon, Coeur de pigeon, Van, and Burlat, respectively. According to the same order, the flavonoids showed amounts of 34.31 ± 2.08, 23.75 ± 1.02, 24.37 ± 1.20, and 23.31 ± 0.90 mg (rutin equivalent) RE/g extract. These values were correlated with the results of the antioxidant assays, where the Napoleon cultivar proved to be the most potent using the DPPH (IC(50) = 2.51 µg/mL) and ABTS (IC(50) = 55.38 µg/mL) assays. The phenolic profile of each extract resulted in the identification of twenty-two compounds belonging to five distinct groups. The major phenolic compounds identified were sakuranetin and dihydrowgonin with their glucosides. Antidiabetic activity assays showed that only stem extracts from Burlat and Napoleon cultivars were able to inhibit the α-amylase enzyme with values of 85.57 ± 1.09% and 68.01 ± 3.52%, respectively. All stem extracts proved their ability to inhibit the xanthine oxidase enzyme which is directly linked to the gout disease, with a high value for Van cultivar (40.63 ± 2.37%). These new findings could provide new opportunities for the valorization of cherry stems for the pharmaceutical application of their active phytochemicals.