Chemical composition of different species of Salvia from Romania (Salvia transsylvanica, Salvia glutinosa, Salvia officinalis) and their biological activities

Background: Sage species are used in Romanian traditional medicine for coughs, rheumatism and inflammatory diseases, as well as antidiabetic remedies. In this study, Salvia glutinosa and the endemic Salvia transsylvanica were compared with the well-known Salvia officinalis in terms of chemical composition and biological activities. Material and Methods: In the current study, an HPLC method was applied for determination of 22 phenolic compounds in dry extracts of S. glutinosa, S. transsylvanica, and S. officinalis. The antioxidant capacity and enzyme inhibitory potential of the extracts were evaluated using microtiter assays, and the antimicrobial potential was tested using the microdiluation assay for eight bacterial and fungal strains. These extracts were further tested on three different cancer cell lines (A549, HepG2 and MCF-7) at increasing concentrations (1.56-200 μg/mL) for 24h/48h to assess a possible cytotoxic activity. Cell viability was evaluated by measuring the capacity of the cells to reduce the non-fluorescent resazurin to resorufin, a fluorescent product. Results: The chromatographic fingerprint revealed that among investigated compounds, the dominant compounds of Salvia species are rutin (1357.9 - 4070.2 μg g-1) and catechin (1112.6 - 1911.1 μg g-1). The biological profile of the three sage extracts was evaluated towards several antioxidant assays, and by testing their inhibitory capacities against key enzymes involved in neurodegenerative diseases, as well as diabetes mellitus. Concerning the antioxidant assays, generally S. officinalis exhibited high antioxidant capacity in all assays, the highest values being obtained for the CUPRAC assay: 400.01 mgTE/g extract for S. officinalis, 175.91 mgTE/g extract for S. glutinosa, and 118.11 mgTE/g extract for S. transsylvanica. Concerning the enzyme inhibitory assays, S. officinalis extract presented the highest inhibitory potential on butyrylcholinesterase (2.40 mgGALAE/g extract) followed by S. transsylvanica (1.43 mgGALAE/g extract). Additionally, both S. officinalis and S. transsylvanica extracts exhibited an important inhibitory potential against alpha-glucosidase (27.01 mmolACAE/g extract, and 25.62 mmolACAE/g extract, respectively). Nevertheless, the most sensitive bacteria to the tested extracts were Enterobacter cloacae (MIC = 0.01 mg/mL, MBC = 0.02 mg/mL for S. officinalis) and Bacillus cereus (MIC = 0.09 mg/mL, MBC = 0.18 mg/mL), while Penicillium funiculosum was the most sensitive fungal strain to S. officinalis extract (MIC = 0.06 mg/mL, MFC = 0.12 mg/mL). From the three extracts tested, the S. officinalis extract exhibited the most potent cytotoxic effect. No major differences in cytotoxicity were observed between the three cell lines, suggesting a common mechanism of toxicity. Interestingly, when testing on the estrogenic responsive cell line MCF-7, an increase in the viability was observed for intermediary doses which we hypothesize to be related to the estrogen-like compounds present in Salvia species. Conclusions: Further studies are needed to elucidate the different mechanisms of action involved, as well as the specific compounds responsible for the tested biological activities. Acknowledgments „This work was supported by a grant of Ministery of Research and Innovation, CNCS - UEFISCDI, project number PN-III-P1-1.1-PD-2016-1900, within PNCDI III”.