Controlled Differential Sieving (CDS), phytochemical profiling, and antioxidant activity of Senna italica (Fabaceae) Leaves

Aims and scope: Senna italica is recognized for its nutritional value and therapeutic potential. Various parts of the plant exhibit pharmacological properties, including antioxidant, hypolipidemic, and antibacterial activities. The main objective of this work was to evaluate the effects of the Controlled Differential Sieving (CDS) process on the phytochemical composition and antioxidant properties of S. italica leaves powder fractions.Methods: The harvested leaves are washed, dried, crushed, pulverized and sieved on a column of sieves with decreasing mesh sizes of 355, 250, 200 and 125 μm. The choice of sieve was based on the results of the particle size and their availability. The fractions retained on each sieve were cleaned, weighed and subjected to evaluation of the antioxidant property. In vitro tests were used to determine their metabolite content and their antioxidant activities.Results: The results showed a significant increase (p˂0.05) in total polyphenol content as particle size decreased, rising from 55.47 ± 2.30 mg GAE/g DM in the ≥355 μm fraction to 75.81 ± 1.51 mg GAE/g DM in the ≤125 μm fraction. The coarse fraction has the highest IC50 (1.15±0.16 µg/mL), while the finest has the lowest IC50 (0.95±0.05 µg/mL) synonymous with greater free radical trapping capacity. Regarding FRAP, The coarse powder have the lowest values (42.90±0.92 mg/g DM) synonymous with low reducing power while the finest fraction has the highest value of iron reducing power which is 59.91±1.90 mg/g DM.Conclusion: S. italica leaf powders have been demonstrated to possess antioxydant properties, with these characteristics being amplified in fine powder fraction.