Comparison of phenolic composition, antiradical and antioxidant activities of diploid and autotetraploid genotypes of Salvia officinalis L.

Abstract

Salvia officinalis L. (Common sage) has been used as a drug in traditional medical treatments and as a spice in the kitchen since ancient times. Cultivated varieties of Salvia officinalis have a diploid (2n = 2x = 14) genome. In this study, six genotypes with autotetraploid genome (2n = 4x = 28) via colchicine-induced polyploid were compared with six diploid genotypes for their nuclear DNA amounts, phenolic compounds and antioxidant activities. It was determined that the average nuclear DNA amount (2.96 pg/2C) of autotetraploid genotypes determined by Flow Cytometry (FC) analysis technique was more than twice the average nuclear DNA amount (1.29 pg/2C) of diploid genotypes. It was found that diploid genotypes contained higher total phenolic content and rosmarinic acid, the most abundat phenolic in Salvia officinalis, than autotatraploid genotypes. Antioxidant and antiradical activities of the extracts were determined using ABTS, β-carotene-linoleic acid, CUPRAC, DPPH, FRAP, and TAC assays. In general, that genotypes with high total phenolic content and phenolic compounds, especially rosmarinic acid, also had high antiradical/antioxidant activities. Compared to autotetraploids, diploid genotypes showed higher antiradical/antioxidant activity in all antioxidant assays except β-carotene-linoleic acid assay. The findings obtained from this study are expected to be an important literature source in terms of evaluating the antioxidant performance of Salvia officinalis with autotetraploid genome.