582 GC-MS Analysis and Biological Activities of Algerian Salvia microphylla Essential Oils

Salvia microphylla is a known species due to its broad uses in traditional medicine against memory loss and rheumatism. The knowledge regarding the chemical composition and biological activities of the species collected in Algeria, no studies have been reported in the literature. Therefore, the present work focuses on the characterization of the chemical composition of the essential oils (EOs) and the determination of the antioxidant, anticholinesterase, α-glucosidase, and antimicrobial activities of Salvia microphylla. The EOs were obtained by hydrodistillation from the aerial parts, leaves and stems and submitted to chemical analysis by GC and GC/MS. The β-Caryophyllene was identified as the main constituent in the aerial parts and leaves essential oils with 16.75 ± 0.02 % and 17.86 ± 0.07 %, respectively. Likewise, the α-Eudesmol was the predominant component in the stems oil with (21.47 ± 0.20 %). The antioxidant activity of EOs was estimated through using four comparative methods: DPPH, ABTS•+, Reducing power and CUPRAC assays. The Stems oil was the most active one in CUPRAC assay, with an IC50 value with 7.72 ± 0.43 μg/mL. The enzyme inhibitory activity of the essential oils was realized against key enzymes involved in type 2 diabetes (α-glucosidase) using 4-Nitrophenyl-α-d-glucopyranoside as substrate and in neurodegenerative (AChE and BChE) diseases. The highest anticholinesterase activity against acetylcholinesterase was observed in the EO of aerial parts essential (IC50: 23.65 ± 0.73 μg/mL). The EO isolated from stems (IC50: 37.07 ± 1.44 μg/mL) exhibited a butyrylcholinesterase activity very close to that of analytical standard galantamine (IC50: 34.75 ± 1.99 μg/mL). Furthermore, all EOs displayed high inhibitory activity against α-glucosidase, better to that of the standard acarbose. The EOs of Salvia microphylla display potential properties against type 2 diabetes. A broth microdilution method was used to evaluate the antimicrobial activity of Salvia microphylla EOs, against eleven microbial strains and two yeast. The EOs showed better antibacterial activity against Gram-positive and Gram-negative bacteria except for Pseudomonas aeruginosa, with the stems essential oil being more efficient. Moreover, significant antifungal activity was observed against Candida albicans.