Unveiling the antidiabetic, anti-inflammatory and anti-hemolytic activities of Raphanus sativus leaves through...

Raphanus sativus L. (Brassicaceae) is a widely consumed plant known for its nutritional and medicinal properties. This study comprehensively investigated the phytochemical composition and multifaceted biological activities of R. sativus leaves collected from the Bulancak (Giresun-Türkiye) region. Unlike previous studies in the literature, which generally focus on the root portion, this study demonstrates the therapeutic potential of the leaves with a multidisciplinary approach. In this study, the extraction, phytochemical analysis, and the activities of locally sourced R. sativus leaves were investigated. High total phenolic (45.6 mg GAE/g) and flavonoid (35.6 mg QE/g) contents were detected in the R. sativus extract. At the same time, rosmarinic acid, p-coumaric acid, and caffeic acid were identified as the major components by liquid chromatography with tandem mass spectrometry. The extracts exhibited antidiabetic activity via enzyme inhibition, with IC₅₀ values ​​ranging from 31.56 to 51.15 µg/mL for α-amylase and 28.4 to 49.65 µg/mL for α-glucosidase. Molecular docking analysis was performed to support the in-vitro antidiabetic activity. Rosmarinic, caffeic, and p-coumaric acids were found to bind to α-amylase and α-glucosidase enzymes via hydrogen bonding and hydrophobic interactions. For anti-inflammatory activity, inhibition of albumin protein denaturation was investigated, and the highest activity was found in the chloroform fraction (72.6%). To confirm protein denaturation inhibitory activity, the spectroscopic interactions of the main compounds, rosmarinic acid and caffeic acid, were investigated. It was observed that as the proportion of rosmarinic acid increased (from 1:1 to 1:4), the absorbance decreased across all wavelengths. In the anti-hemolytic activity test, the chloroform fraction showed the highest effectiveness against 2,2'-Azodiisobutyramidine dihydrochloride-induced erythrocyte hemolysis with 69.35% protection at 100 µg/mL. Overall, the results indicate that R. sativus leaves possess potent antidiabetic, anti-inflammatory, and antihemolytic properties, making them an important natural resource with potential for the development of functional foods or pharmaceutical products.