Polyphenol Compounds and Antioxidant Activity of Salvia officinalis L. and Salvia sclarea L.

Abstract

The plants from Salvia L. (sage) genus are well-known as culinary, ornamental, aromatic, and medicine plants widely distributed in the world. The plant raw of these plants contains numerous biologically active compounds that determine the different biological activities. This study aimed to evaluate the antioxidant activity and polyphenol content of ethanol extracts of Salvia officinalis L. and S. sclarea L. during vegetation. Plant raw material was collected from an experimental collection of aromatic and medicinal plants of the Institute of Climate Smart Agriculture of the National Academy of Agrarian Sciences of Ukraine (Kherson region, v. Plodove) in 2020–2021. It investigated polyphenol, phenolic acid, flavonoid content, molybdenum-reducing power of extracts, and radical scavenging activity by the DPPH method. The total polyphenol compound content was 24.52–95.62 mg GAE.g^-1 (mg gallic acid equivalent per gram) for S. officinalis and 29.39–91.02 mg GAE.g^-1 for S. sclarea. The total phenolic acid content of S. officinalis and S. sclarea extracts was 10.18–40.23 and 10.13–36.01 mg CAE.g^-1 (mg caffeic acid equivalent per gram), respectively. The total flavonoid content was from 13.73 to 55.38 mg QE.g^-1 (quercetin equivalen per gram) for S. officinalis and from 25.91 to 53.82 mg QE.g^-1 for S. sclarea. The free radical scavenging activity of ethanol extracts of S. officinalis and S. sclarea was 6.05–8.59 mg TE.g^-1 (mg Trolox equivalent per gram) and 6.56–8.03 mg TE.g^-1, respectively. The extracts of S. officinalis showed molybdenum-reducing power from 56.25 to 218.67 mg TE.g^-1 and S. sclarea extracts from 35.42 to 162.65 mg TE.g^-1. A strong correlation was found between free radical scavenging activity and polyphenol compound groups (r = 0.723–0.868), and between molybdenum-reducing power and polyphenol compound groups (r = 0.759–0.927) for S. officinalis. Strong relations were found in extracts of S. sclarea between molybdenum-reducing power and investigated polyphenol compounds (r = 0.802–0.909), whereas, free radical scavenging activity weak correlated with investigated compounds. Thus, this study showed that S. officinalis and S. sclarea extracts are a source of antioxidant compounds that can be used in the pharmaceutical and food industries. Most content of antioxidant compounds is found in the leaf and inflorescence extracts.