The spinach (Spinacia oleracea) plants treated with certain seed priming (bio-fertilizer and Humic acid) and foliar treatments
(Humic acid, Moringa leaf extract, 6-Benzyl amino purine etc.) were tested for total phenolic content and the antioxidant
activity. Methanolic extracts of all spinach samples were assessed performing three different protocols including FolinCiocalteu, reducing power and DPPH radical scavenging assays. TPC value ranged 4.678-13.236 mg GAE/g of dry matter.
Reducing power assay showed values (absorbance at λmax=700nm) in the range of 0.351-1.874 at 10 mg/mL extract
concentration. The range of IC50 values in DPPH radical scavenging assay was 0.499-1.063 µg/mL extract concentration. The
one way ANOVA under CRD showed significant differences among treatments. Among various plant growth regulators,
fresh Moringa leaf extract proved as the potent enhancer of antioxidant activity of spinach leaves.
