Component Composition and Biological Activity of Various Extracts of Onosma gmelinii (Boraginaceae).

Onosma roots are widely used in traditional medicine to treat various diseases throughout the world. In this study, for the first time, we investigated the component composition and biological activity of various extracts from the roots of Onosma gmelinii collected in the highlands of the Kakpakty Mountains of the Almaty region (Republic of Kazakhstan). Extracts were obtained by three different methods: percolation extraction, ultrasound-assisted extraction, and supercritical carbon dioxide extraction. The component composition of the extracts was determined by gas chromatography/mass spectrometry (GC/MS), naphthoquinones by thin-layer chromatography (TLC), and spectrophotometric method. In this study, the presence of shikonin and its derivatives in the extracts was confirmed. The concentration of naphthoquinones during CO2 extraction was about 40%, during ultrasonic extraction about 3%, and during percolation extraction about 1.3%. The GC-MS method identified 69 chemical compounds in the ultrasonic extract, 46 compounds in the CO2 extract, and 51 compounds in the percolation extract. The extracts were tested on a panel of bacteria and viruses: two Gram-negative bacteria (Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 9027); nine Gram-positive bacteria (Staphylococcus aureus ATCC 6538-P, Staphylococcus aureus ATCC BAA-39, Staphylococcus epidermidis ATCC 51625, Staphylococcus epidermidis ATCC 12228, Streptococcus pyogenes ATCC 19615, Streptococcus pneumoniae ATCC BAA-660, Enterococcus hirae ATCC 10541, Enterococcus faecalis ATCC 51575, Enterococcus faecium ATCC 700221); and two fungal species (Candida albicans ATCC 10231, Candida albicans ATCC 2091); five subtypes of influenza virus A (A/FPV/Weybridge/78 (H7N7), A/Swine/Iowa/15/30 (H1N1), A/black-headed gull/Atyrau/743/04 (H13N6), A/FPV/Rostock/1934 (H7N1), A/Almaty/8/98 (H3N2)). The root extracts of Onosma gmelinii showed antibacterial activity in different degrees against all tested Gram-positive bacterial strains, while no inhibitory effect on Gram-negative bacteria was observed. The results indicated that the ultrasonic extract effectively inhibits the growth of the majority of tested Gram-positive bacteria (MBC from 18.3 to 293.0 µg/mL). CO2 extract had the greatest bactericidal activity (MBC from 0.1 to 24.4 µg/mL). Percolation extract insignificantly inhibited bacterial growth (MBC from 2343.8 to 4687.5 µg/mL). CO2 extract and ultrasonic extract significantly reduced the activity of C. albicans. The results of the antiviral action showed that the ultrasonic extract has the greatest effectiveness against different subtypes of the influenza virus A, while other extracts did not show significant activity.

Transcriptomics and methylomics study on the effect of iodine-containing drug FS-1 on Escherichia coli ATCC BAA-196.

Aim: Promising results on application of iodine-containing nano-micelles, FS-1, against antibiotic-resistant Escherichia coli was demonstrated. Materials & methods: RNA sequencing for transcriptomics and the complete genome sequencing by SMRT PacBio were followed by genome assembly and methylomics. Results & conclusion: FS-1-treated E. coli showed an increased susceptibility to antibiotics ampicillin and gentamicin. Cultivation with FS-1 caused gene expression alterations toward anaerobic respiration, increased anabolism and inhibition of many nutrient uptake systems. Main targets of iodine-containing particles were cell membrane structures causing oxidative, osmotic and acidic stresses. Identification of methylated nucleotides showed an altered pattern in the FS-1-treated culture. Possible role of transcriptional and epigenetic modifications in the observed increase in susceptibility to gentamicin and ampicillin were discussed.

Lay abstract New approaches of combatting drug-resistant infections are in demand as the development of new antibiotics is in a deep crisis. This study was set out to investigate molecular mechanisms of action of new iodine-containing nano-micelle drug FS-1, which potentially may improve the antibiotic therapy of drug-resistant infections. Iodine is one of the oldest antimicrobials and until now there were no reports on development of resistance to iodine. Recent studies showed promising results on application of iodine-containing nano-micelles against antibiotic-resistant pathogens as a supplement to antibiotic therapy. The mechanisms of action, however, remain unclear. The collection strain Escherichia coli ATCC BAA-196 showing an extended spectrum of resistance to ßß-lactam and aminoglycoside antibiotics was used in this study as a model organism. Antibiotic resistance patterns, whole genomes and total RNA sequences of the FS-1-treated (FS) and negative control (NC) variants of E. coli BAA-196 were obtained and analyzed. FS culture showed an increased susceptibility to antibiotics associated with profound gene expression alterations switching the bacterial metabolism to anaerobic respiration, increased anabolism, osmotic stress response and inhibition of many nutrient uptake systems. Nucleotide methylation pattern were identified in FS and NC cultures. While the numbers of methylated sites in both genomes remained similar, some peculiar alterations were observed in their distribution along chromosomal and plasmid sequences.

Determination of the Chemical Composition and Antimicrobial Activity of Lavatera thuringiaca L. Medicinal Herb Material Extracted under Subcritical Conditions by the Liquid Carbon Dioxide Method.

This article presents the composition of the components of Lavatera thuringiaca L. (Malvaceae Juss. family), which has a certain antibacterial effect. The plant collection was carried out in the Shamalgan gorge of Mountain Range of the Trans-Ili Alatau in the territory of the Karasay district of the Almaty region, in the flowering phase. A CO2 extract of the aboveground part of the medicinal plant Lavatera thuringiaca L. was obtained under subcritical conditions and, for the first time, studied for its component composition and antimicrobial activity. Determination of the chemical composition of the extract was carried out by gas chromatography/mass spectrometry (GC/MS). To identify the obtained mass spectra, we used the Wiley 7th edition and the NIST'02 data library. To determine the antimicrobial and antifungal activity, standard test strains of microorganisms were used: Staphylococcus aureus ATCC 6538-P, Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 9027, Candida albicans ATCC 10231, Streptococcus pneumonia ATCC 660, Klebsiella pneumoniae ATCC 700603, Staphylococcus haemolyticus, and Staphylococcus saprophyticus. In the composition of thick CO2 Lavatera thuringiaca L. extract, the content of 31 components was proven: spathulenol 6.97%, pulegone 5 08%, cis-ß-farnesene 7.63%, verbenone 1.93%, α-bisabolol oxide B 9.65%, bisabolol oxide A 8.26%, α-bisabolol 1.36%, linolenic acid, ethyl ether 3.15%, phytol 2.49%, herniarin 5.61%, linolenic acid 9.38%, linoleic acid 6.95%, myristic acid 2.33%, and elaidic acid 2.57%. Antimicrobial activity studies have shown that the CO2 extract of Lavatera thuringiaca L. has a pronounced effect against clinically significant microorganisms: Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Streptococcus pneumonia, Klebsiella pneumoniae, Staphylococcus haemolyticus, and Staphylococcus saprophyticus. During testing, the method of serial dilutions proved that the extract of Lavatera thuringiaca L. has a bactericidal effect on Staphylococcus aureus at a concentration of 0.83 µg/µl, on Escherichia coli at a concentration of 3.33 µg/µl, on Pseudomonas aeruginosa at a concentration of 0.83 µg/µl, on Streptococcus pneumoniae at a concentration of 1.67 µg/µl, on a clinical isolate of Staphylococcus haemolyticus at a concentration of 26.65 µg/µl, on Staphylococcus saprophyticus at a concentration of 6.67 µg/µl, and against Klebsiella pneumoniae at a concentration of 13.36 µg/µl. The test result showed that the extract also has fungicidal activity against the test culture of Candida albicans at a concentration of 0.21 µg/µl. At tests, the disc diffusion method proved that the extract has antimicrobial activity with high values of the growth suppression zone exceeding 15 mm. The zones of growth retardation of the test strains were 19.33 ± 1.15 for Staphylococcus aureus; 17.33 ± 3.21 for Escherichia coli; 15.67 ± 0.57 for Pseudomonas aeruginosa; 20.0 ± 1.0 for Streptococcus pneumoniae; 16.0 ± 2.64 for Klebsiella pneumoniae; 15.0 ± 1.0 for Staphylococcus saprophyticus, and 22.0 ± 1.73 for Candida albicans. In relation to the clinical isolate of Staphylococcus haemolyticus, the extract has a bacteriostatic effect.

Chitosan/Poly(2-ethyl-2-oxazoline) Films with Ciprofloxacin for Application in Vaginal Drug Delivery.

Chitosan (CHI) and chitosan/poly(2-ethyl-2-oxazoline) (CHI/POZ)-based films were prepared by casting from aqueous solutions of polymer blends with different compositions. Ciprofloxacin was used as a model drug in these formulations. The weight, thickness, folding endurance and transparency of blend films were measured and characterised. All films had a uniform thickness (0.06 ± 0.01 mm) and exhibited sufficient flexibility. The surface pHs of films ranged from 3.76 ± 0.49 to 4.14 ± 0.32, which is within the pH range suitable for vaginal applications. The cumulative release of the drug from the films in experiments in vitro was found to be 42 ± 2% and 56 ± 1% for pure CHI and CHI/POZ (40:60) films, respectively. Drug-free chitosan/poly(2-ethyl-2-oxazoline) films showed weak antimicrobial activity against Escherichia coli. Drug-loaded CHI and CHI/POZ films showed good antimicrobial properties against both Gram-positive Staphylococcus aureus and Gram-negative bacteria Escherichia coli. Mucoadhesive properties of these films with respect to freshly excised sheep vaginal mucosa were evaluated using a tensile method. It was established that all films were mucoadhesive, but an increase in POZ content in the blend resulted in a gradual reduction of their ability to stick to vaginal mucosa. These films could potentially find applications in vaginal drug delivery.