Effect of Agricultural Model of using Fertilizer, Harvesting Time and Extraction Method on Phytochemical Contents and Antioxidant Activities from Mulberry Leaves Grown in Maha Sarakham Province, Thailand

Aims: Phytochemical contents and free radical scavenging of Mulberry leaf extracts by using different fertilizer, time of harvesting and solvent extraction were evaluated. Materials and Methods: Dried Mulberry leaves were extracted by using different solvent including aqueous, 50% ethanol and 95% ethanol. The phytochemical screening were determined by Total Phenolic Compounds (TPC) and Total Flavonoid Contents (TFC). The anti-oxidation were tested by using 2,2-diphenyl-1-picrylhydrazy (DPPH) radical scavenging and 2,2 -azinobis-(3- ethylbenzothiazoline-6-sulphonate) (ABTS⁺) assay. Results: This experimental study found that the mulberry leaf extract were given extraction with 95% ethanol, all of fertilizer and at Week 4 showed highest total phenolic contents espectcially BET2 was high amount of TPC (124.444±0.609 mgGE/gExt). The harvest time, all of groups at the Week 4 were significantly higher than all of groups at the Week 2. On the other hand, total flavonoid contents, the DET1 (Fertilizer formula 15-15-15, extraction with 95% ethanol at the Week 2; 110.913±3.208 mgQE/gExt) showed highest amount. The Antioxidant activities, DPPH free radical scavenging activity, The groups were given extraction with 95% ethanol, all of fertilizer at the Week 4 including CHT2 (IC₅₀ =0.00459±0.00001 mg/mL), BHT2 (IC₅₀ =0.00487 ±0.00005 mg/mL), AHT2 (IC₅₀ =0.00499±0.00007 mg/mL), DHT2 (IC₅₀ =0.00499±0.00005 mg/mL) and EHT2 (IC₅₀ =0.00667 ±0.00039 mg/mL) were more potent on free radical scavenging higher than all of groups. The ABTS+ assay, at the Week 2 of all fertilizer groups were given with all solvent extraction including BHT1 (IC₅₀ =0.03191±0.00257 mg/mL), CHT1 (IC₅₀ =0.03247±0.00044 mg/mL), AHT1 (IC₅₀ =0.03320±0.00120 mg/mL), EHT1 (IC₅₀ =0.03342±0.00116 mg/mL) and AAT1 (IC₅₀ =0.03792±0.00076 mg/mL) showed free radical scavenging activity not different from standard substances, ascorbic acid (IC₅₀ =0.00699 ±0.00004 mg/mL) and Trolox^ (IC₅₀ =0.01594±0.00116 mg/mL). Conclusion: The study was undertaken to investigate it’s fertilizer use, harvest time and extraction method for biologically activities also chemical composition contents and their antioxidant potentials. Therefore, our data might be help to good cultivation and harvesting practice selection in order to produce better of mulberry leaf production.