ABSTRACT
The Stachys L. genus has been widely used in traditional medicine in many countries throughout the world. The study aimed to investigate the chemical composition and bioactivity of the hydroethanolic extract (50% v/v) obtained by ultrasonication from the aerial flowering parts of Stachys sylvatica L. (SSE) collected in Almaty region (Southern Kazakhstan). According to RP-HPLC/PDA analysis the leading metabolites of the SSE belonged to polyphenols: chlorogenic acid and its isomers (2.34 mg/g dry extract) and luteolin derivatives (1.49 mg/g dry extract), while HPLC-ESI-QTOF-MS/MS-based qualitative fingerprinting revealed the presence of 17 metabolites, mainly chlorogenic acid and its isomers, flavonoid glycosides, and verbascoside with its derivatives. GC-MS analysis of the volatile metabolites showed mainly the presence of diterpenoids and fatty acid esters. A reduction in the viability of nematodes Rhabditis sp. was obtained for the SSE concentration of 3.3 mg/mL, while 11.1 mg/mL showed activity comparable to albendazole. The SSE exhibited higher activity against Gram-positive (MIC = 0.5-2 mg/mL) than Gram-negative bacteria and yeast (MIC = 8 mg/mL), exerting bactericidal and fungicidal effects but with no sporicidal activity. The SSE showed some antiviral activity against HCoV-229E replicating in MRC-5 and good protection against the cytopathic effect induced by HHV-1 in VERO. The SSE was moderately cytotoxic towards human cervical adenocarcinoma (H1HeLa) cells (CC50 of 0.127 mg/mL after 72 h). This study provides novel information on the SSE extract composition and its biological activity, especially in the context of the SSE as a promising candidate for further antiparasitic studies.
ABSTRACT
BACKGROUND: Extracts from medicinal plants with phytochemicals with known antimicrobial properties can be an effective adjunct in the complex treatment of infectious diseases. This study aimed to evaluate the antimicrobial activity of wormwood extracts collected in Kazakhstan (Artemisia gmelinii Weber ex Stechm.), along with their phytochemical analysis. METHODS: The ethanolic and chloroform extracts were subjected to HPLC combined with quadrupole time-of-flight mass spectrometry method. For quantitative assessment of antimicrobial activity, minimal inhibitory concentration (MIC) of the tested extracts was determined by micro-dilution broth method for the panel of the reference microorganisms. Minimal bactericidal concentration (MBC) or minimal fungicidal concentration (MFC) were also determined. RESULTS: LC/MS analysis showed the presence of 13 compounds in the tested extracts, including flavonoids: apigenin, luteolin, rutin, two O-methylated flavonols (isorhamnetin, rhamnazine), coumarin compounds (umbelliferone, scopoletin and scopolin (scopoletin 7-glucoside), 3-hydroxycoumarin and 4-hydroxycoumarin), chlorogenic acid and two dicaffeoylquinic acid isomers. Quantitative HPLC analysis showed that umbelliferone was dominant in the chloroform extract while chlorogenic acid was identified as a main compound in the ethanolic extract. The antibacterial and antifungal activity of chloroform and ethanolic extracts was comparable. The most sensitive were the Gram-positive bacteria represented by staphylococci, Micrococcus luteus and Bacillus spp. (MIC = 1.25-5 mg/ml) and yeasts represented by Candida spp. (MIC = 2.5-5 mg/ml), irrespective of the assayed extract. CONCLUSIONS: Extracts of wormwood Artemisia gmelinii have shown a wide spectrum of antibacterial and antifungal activity. Luteolin, rutin, isorhamnetin and scopolin were identified in A. gmelinii species for the first time. The determining of the most potential compounds of Artemisia gmelinii can be used to develop effective antibacterial and antifungal agents.
