Phenolic Compounds, Antioxidant and Cytotoxic Activity in Berry and Leaf Extracts of Black Currant (Ribes nigrum L.) as affected by Soil Management Systems

Abstract

This experiment evaluated the effect of soil management systems (bare fallow, sawdust mulch and black plastic mulch) on the contents of phenolic compounds (total phenolics, flavonoids, gallotannins and condensed tannins), antioxidant activity (DPPH free radical scavenging activity, hydroxyl radical scavenging activity, lipid peroxidation) and cytotoxic activity in berry and leaf extracts of seven black currant cultivars. Soil management systems and cultivars showed highly significant differences in the content of phenolic compounds, antioxidant and cytotoxic activity. Sawdust mulch and bare fallow treatments had a significant positive effect on the synthesis of phenolic compounds and antioxidant activity in both berries and leaves. On the other hand, black currants grown on black plastic mulch had the highest cytotoxic activity. The tested extracts showed strong antioxidant and cytotoxic potential. Antioxidant activity expressed as the 50% inhibition concentration (IC50 value) ranged from 31.62 to 59.13 µg/mL and from 64.06 to 81.90 µg/mL, while cytotoxic activity varied from 15.91 to 37.89 µg/mL and from 26.28 to 38.18 µg/mL for berries and leaves extracts, respectively. Generally, the results suggested that black currants grow well under varied soil management systems, and indicated that soil management systems had a significant effect on the synthesis and accumulation of the tested parameters.