Screening Effects of Methanol Extracts of Diplotaxis tenuifolia and Reseda lutea on Enzymatic Antioxidant Defense Systems and Aldose Reductase Activity

Objectives: The aim of the study was to investigate the effects of methanol extracts from the flowers and leaves of Diplotaxis tenuifolia and Reseda lutea on the activity of AR, CAT, GST, and GPx.

Materials and methods: Total phenolic and flavonoid contents of the plant samples were evaluated using Folin-Ciocalteu reagent and aluminum chloride colorimetric methods. Also, the effects of extracts on CAT, GST, GPx, and AR enzyme activities were investigated using kinetic assays.

Results: The highest phenolic and flavonoid contents were detected in the methanol extract of D. tenuifolia leaves with 144.49±0.29 mg gallic acid equivalent/L and 250.485±0.002 quercetin equivalent/L, respectively. The best activity profile for GST and GPx were observed in the extract of leaves belonging to D. tenuifolia with IC₅₀ values of 121±0.05 and 140±0.001 ng/mL, respectively. According to the results, methanol extracts from leaves of R. lutea and D. tenuifolia showed no significant activity potential on AR. Moreover, none of the studied extracts demonstrated any reasonable CAT activation potential.

Conclusion: The results indicated that leaves of D. tenuifolia had good effect on the antioxidant enzymatic defense system, which it makes it a good constituent of the daily diet.

Keywords: Diplotaxis tenuifolia; Reseda lutea; aldose reductase; antioxidant enzymes.