Comprehensive phytochemical characterization of Raphanus raphanistrum L.: In vitro antioxidant and antihyperglycemic evaluation

Abstract

Raphanus raphanistrum L. is an edible flowering plant that belongs to the Brassicaceae family and is also known as wild radish. Recently, it was reported as a sustainable source of bioactive compounds and nutrients. For comprehensive metabolites profiling of R. raphanistrum whole plant, three types of extracts; aqueous ethanol (AEE), dichloromethane (DCME), and defatted aqueous ethanol (DAEE), were prepared. DCME was investigated by GC/MS analysis and led to the characterization of twenty-nine compounds from the unsaponifiable fraction and fourteen compounds from the saponifiable one. Likewise, the HPLC-MS/MS analysis of AEE aided with the molecular networking via the GNPS platform, resulting in the annotation of 99 metabolites belonging to different chemical classes. Besides, seven compounds were isolated from the DAEE, five of them are reported for the first time from R. raphanistrum. In parallel, the antioxidant evaluation revealed that DCME has the most potent activity using DPPH· and NO· scavenging assays with IC50 (117.68 & 162.31 µg/mL), compared to ascorbic acid (244.85 & 117.12 µg/mL) and BHT (90.82 & 76.69 µg/mL), respectively. DCME also gave the highest α-amylase and α-glucosidase inhibitory activities with an IC50 (µg/mL) of 150.72 and 123.16, respectively. Among the tested compounds, isorhamnetin 3-O-rutinoside showed the highest activity with an IC50 (µg/mL) 274.68 and 195.87, respectively on the same investigated enzymes. As far as we can tell, the current work is considered the full chemical characterization and first antihyperglycemic evaluation of the wild radish.

Keywords

• Antioxidant
• α-amylase
• α-glucosidase
• GC/MS
• HPLC-MS/MS
• Molecular networking