Stachys Species: Comparative Evaluation of Phenolic Profile and Antimicrobial and Antioxidant Potential

Stachys italica Mill.: synecology, functional compounds and potential use of an Italian endemic taxon

MAIN CONCLUSION

The metabolomic of the Italian endemic species Stachys italica was investigated and potential positive metabolites for human's health were detected, quantified and discussed in relation to its synecology. Stachys italica is a species endemic to central-southern Italy, traditionally used for human consumption. The present research reports the results of a phytosociological study of this species in two southern regions of Italy (Apulia and Calabria). The collected plant material was used to make two types of extracts: hot water infusion to evaluate the use of this plant as tea and hydroalcoholic extraction to evaluate the use of it in herbal liqueur preparation. The extracts obtained by the hot water infusion had a values of total polyphenols and antioxidant capacity similar to values found in black tea. The analysis of non-volatiles compounds revealed the presence of biologically active substances like lavandulifolioside, verbascoside, and methoxyflavones. The analysis of volatiles fraction of metabolites demonstrated fifty-three volatiles compounds in the plant aerial part, 19 of which belonging to monoterpenoids, and 17 to the class of sesquiterpenoids. Among them, α-pinene, β-pinene, cis-ocimene, limonene and t-caryophyllene, were the most abundant compounds. The results were compared with already published results and referred to other similar species (such as Sideritis syriaca) which represent herbal mixtures usually collected and used as "mountain tea" in the Balkans and Eastern European countries.

Antioxidant and Antimicrobial Properties of Stachys maritima via Quantum Dots and Molecular Docking

Stachys maritima is a species of plant belonging to the Lamiaceae, commonly known as common sea lavender. The extraction of S. maritima involves drying the aerial parts, grinding them into powder, followed by extraction with methanol. ST-CQDs (S. maritima carbon quantum dots) were synthesized from S. maritima extract via pyrolysis. An optimal synthesis condition of 7 hours of pyrolysis was determined to yield ST-CQDs with high absorption in the visible-UV range. Characterization techniques such as UV-visible spectroscopy and TEM (Transmission Electron Microscopy) confirmed the spherical and homogeneous nature of the carbon quantum dots. S. maritima methanol extract exhibited strong antioxidant activity with a DPPH (2,2-Diphenyl-1-picrylhydrazyl) IC50 value of 0.114±0.001 mg/mL. Similarly, ST-CQDs showed strong antioxidant properties with a DPPH IC50 value of 0.69±0.03 mg/mL. Moreover, the methanol extract of S. maritima demonstrated antimicrobial activity against E. coli ATCC 25922 and S. aureus ATCC 25923, with effective MIC values of 25 mg/mL and 6.25 mg/mL, respectively. However, ST-CQDs did not show antimicrobial effects against the tested microorganisms (E. coli ATCC 25922, S. aureus ATCC 25923, K. pneumoniae ATCC 13883, and C. albicans ATCC 10231). Molecular docking simulations suggested that compounds derived from S. maritima (such as 9,12,15-octadecatrienoic acid and palmitic acid) could interact effectively with TNF-α (Tumor Necrosis Factor Alpha), indicating potential anti-inflammatory properties. This study highlights that the methanol extract of S. maritima possesses potent antioxidant and antimicrobial activities, and ST-CQDs exhibit similar antioxidant properties. However, ST-CQDs did not demonstrate antimicrobial activity against the tested pathogens. Molecular docking simulations also suggest potential anti-inflammatory properties of compounds derived from the plant.

Anthelminthic and antimicrobial effects of hedge woundwort (Stachys sylvatica L.) growing in Southern Kazakhstan

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.

The Antioxidant, Antibacterial and Cell-Protective Properties of Bioactive Compounds Extracted from Rowanberry (Sorbus aucuparia L.) Fruits In Vitro

Considering that Sorbus aucuparia fruits have been underutilized despite their tremendous potential, this study aimed to correlate the in vitro antioxidant, antibacterial and cell-protective abilities of fruit extracts derived from Sorbus aucuparia Romanian cultivars with their phytochemical composition. Therefore, following the preparation of ethanolic and carotenoid extracts, phytochemical screening was performed using UV-Vis and HPLC-DAD-ESI-MS methods. The antioxidant activity was analyzed using DPPH and FRAP tests. As the results revealed high contents of bioactive compounds (polyphenols 1.11 mg GAE/g DM, flavonoids 430.06 µg QE/g DM and carotenoids 95.68 µg/g DM) and an important antiradical action (DPPH 24.51 mg/mL and FRAP 0.016 µM TE/mL), we chose to further examine the fruits' biological properties. The antibacterial capacity was assessed employing agar well diffusion and broth microdilution techniques, with fruits displaying an intense activity against MSSA, MRSA and Enterococcus faecalis, but also E. coli and Pseudomonas aeruginosa. The cell-protective activity was analyzed on gentamicin-stressed renal cells, through MTT and Annexin V-FITC assays. Importantly, a significant increase in viability was registered on stressed cells following extract administration in low doses; nevertheless, viability was noticed to decline when exposed to elevated concentrations, potentially due to the cumulative actions of the extract and gentamicin. These findings offer novel light on the antibacterial activity of Sorbus aucuparia Romanian cultivars, as well as their cell-protective ability in renal cell injury.