Influence of Application Forms of Alginite on Phytomass Formation, Bioactive Contents and Antioxidant Activity of Extracts from Plants Rosmarinus officinalis L.

Abstract

In this study, we compared the effect of soil-climatic factors and application forms of alginite on the weight of vegetable drug, total content of polyphenols, flavonoids, phenolic acids, and antioxidant activity of extracts from Rosmarinus officinalis L. The experiment was based on a site in Tornal (SR), in 2020. The plot was divided into three equal (1m²) parts (variants), on which 9 plants were planted and alginite was applied in two forms. On variant (V₁) alginite was incorporated in powder form, (V₂) alginite in the form of a top dressing (1:10) and control (V_K) without application. When the effect of alginite application on plant weight was evaluated, the highest increase (508.8 g) was observed in variant (V₁), followed by (V₂) (469.6 g) and the lowest value (251.2 g) in (V_K). The highest total amount of flavonoids expressed as quercetin equivalent (QE) was determined in acetone extracts of Rosmarinus officinalis samples in variant (V₁) 0.3225 mg QE.100g^-1 DW. In the extract of the drug from variant (V₂) we determined the total amount of flavonoids to be 0.2922 mg QE.100g^-1 DW and in the control (V_K) 0.2235 mg QE.100g^-1 DW. In the aqueous extracts of Rosmarinus officinalis samples, we determined the highest total polyphenol content converted to caffeic acid equivalent (CAE) per 100 g dry drug in variant (V₁) (27.69 mg CAE.100g^-1 DW), followed by variant (V₂) (26.13 mg CAE.100g^-1 DW) and in the control (V_K) it was 16.42 mg CAE.100g^-1 DW. In the ethanolic extracts of Rosmarinus officinalis samples, we determined the total phenolic acid content converted to caffeic acid equivalent (CAE) per 100 g of dried drug in variant (V₁) (34.61 mg CAE.100g^-1 DW) > (V₂) (33.41 mg CAE.100g^-1 DW) > (V_K) (29.32 mg CAE.100g^-1 DW). The antioxidant activity of methanol extracts of samples from variants V₁, V₂, V_K was expressed as % inhibition of DPPH radical. The highest percentage of inhibition (37.76%) was observed in the drug methanol extract (V₁), followed by variant (V₂) (30.77%) and control (V_K) (15.38%). The results showed that alginite as compared to control significantly affects the growth, weight of Rosmarinus officinalis and increases the content of total polyphenols, flavonoids, phenolic acids, and antioxidant activity, which is crucial in terms of production of medicinal plants, as well as their pharmaceutical uses.