This study evaluated the roles of zeatin (2 mg/L) on direct organogenesis, phytochemical compounds, antioxidant activity, and cytotoxic activity in regenerated shoots of red cabbage. The results revealed that the extract of explant treated by 2 mg/L zeatin gives the highest content of total phenolics (5.18 mg gallic acid equivalent/g dry weight) and flavonoids (1.52 mg rutin equivalent/g dry weight). Moreover, HPLC and GC-MS analyses indicated that various bioactive compounds in red cabbage are significantly enhanced with increasing zeatin concentration. Besides that, antioxidant activity test showed that in vitro shooting culture using 2 mg/L zeatin displayed higher antioxidant activity in all assays (DPPH, FRAP and ABTS) compared to control with respective values of 68.12%, 73.28%, and 54.1%, respectively. Finally, the cytotoxic properties illustrated that the extracts of red cabbage explant treated by 2 mg/L zeatin exhibited the strongest cytotoxic effect towards cancer cells compared to control.
Keywords: Antioxidant activity; Cytokinins; Efficient plant regeneration; Red cabbage.