Comparative Antioxidant, Anti-Acetylcholinesterase and Anti-α-Glucosidase Activities of Mediterranean Salvia Species

Abstract

Salvia species have a cosmopolitan distribution and comprise several well-known plants valuable for pharmaceutical and food industries due to their recognized medicinal, food flavouring, and preservative properties. The present study aimed to evaluate and compare the biological activities of seven wild-growing Salvia species from the Mediterranean area (S. fruticosa, S. glutinosa, S. nemorosa, S. officinalis, S. pratensis, S. sclarea, S. verticillata). All studied ethanolic leaf extracts exhibited significant DPPH and NO radical scavenging ability, lipid peroxidation inhibition, and reducing power, as well as moderate iron-chelating properties. Together with S. officinalis and S. fruticosa, S. verticillata showed anti-acetylcholinesterase activity, while S. glutinosa was also found to possess the ability to inhibit α-glucosidase. Total flavonoid (0.37-0.90%), phenolic acid (3.55-12.44%), tannin (1.22-2.60%), and anthocyanin contents (0.03-0.08%) were determined in Salvia leaves. Rosmarinic acid was the predominant hydroxycinnamic acid in all studied sage plants, ranging from 9400 to 38,800 μg/g. The correlation study showed a strong relationship between biological activities and contents of total phenolic acids, total tannins, and rosmarinic acid, indicating their significant contribution to the efficiency of tested Salvia species. Our results highlighted Mediterranean sage plants as rich sources of potent antioxidant, neuroprotective, and hypoglycemic agents which are worthy of further research.

Keywords: Salvia species; acetylcholinesterase inhibition; antioxidant activity; polyphenols; rosmarinic acid; α-glucosidase inhibition.

Figure 1

Comparative overview of antioxidant effects (IC₅₀ values) of the ethanolic extracts of S. fruticosa (Sf), S. glutinosa (Sg), S. nemorosa (Sn), S. officinalis (So), S. pratensis (Sp), S. sclarea (Ss), and S. verticillata (Sv), as well as rosmarinic acid (R), trolox (T), and EDTA obtained for (a) DPPH scavenging activity, (b) NO scavenging activity, (c) reducing power, (d) iron chelating activity, (e) lipid peroxidation inhibition. The data are expressed as mean values of three independent experiments ± standard deviation and different small letters indicate a statistically significant difference (Tukey’s multiple comparisons test at 95% confidence level).

Figure 1

Comparative overview of antioxidant effects (IC₅₀ values) of the ethanolic extracts of S. fruticosa (Sf), S. glutinosa (Sg), S. nemorosa (Sn), S. officinalis (So), S. pratensis (Sp), S. sclarea (Ss), and S. verticillata (Sv), as well as rosmarinic acid (R), trolox (T), and EDTA obtained for (a) DPPH scavenging activity, (b) NO scavenging activity, (c) reducing power, (d) iron chelating activity, (e) lipid peroxidation inhibition. The data are expressed as mean values of three independent experiments ± standard deviation and different small letters indicate a statistically significant difference (Tukey’s multiple comparisons test at 95% confidence level).