Antibacterial activity of plant-derived compounds and cream formulations against canine skin bacteria.

An urgent need to find alternative antimicrobial compounds effective in the prevention and treatment of skin infections led us to study the inhibitory activity of eight plant-derived bioactive compounds (betulin, curcumin, glycyrrhizic acid, guaiazulene, piperine, quercetin, quinine, tannic acid) against 14 canine skin isolates (11 Gram-positive and three Gram-negative bacteria) selected based on antibiotic resistance and virulence features. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined using the broth microdilution method. In detail, the results for the eight different plant compounds showed their inhibitory activity in the concentration range from 0.04 to more than 16 mg/ml (MIC) and from 0.25 to more than 16 mg/ml (MBC). The most potent compounds appear to be tannic acid, followed by quinine and curcumin (MIC 0.04-16.0 mg/ml). The most susceptible strain to the tested agents in general was Bacillus cereus AE13, while Enterococcus faecium AA14 was the most resistant strain (the highest MICs) among the tested bacteria. The two most potent plant-derived compounds (tannic acid and quinine) were tested in mixture in different ratios (1:1, 1:2, 2:1). The lowest MIC and MBC values were observed for the 1:2 ratio, which was used for preparation of creams with different cream bases. One of the cream formulations (cream F) was effective up to 63.0 mg/ml (MIC) with a microbial inactivation time of 1-6 h according to the tested strain. This study provides evidence that some plant-derived compounds could have an antimicrobial effect against canine skin bacteria, the strength of which is bacterial strain dependent.

Formulation optimization and evaluation of oromucosal in situ gel loaded with silver nanoparticles prepared by green biosynthesis.

Treating oral diseases remains challenging as API is quickly washed out of the application site by saliva turnover and mouth movements. In situ gels are a class of application forms that present sol-gel transition's ability as a response to stimuli. Their tunable properties are provided using smart polymers responsible for stimuli sensitivity, often providing mucoadhesivity. In this study, antimicrobial in situ gels of thermosensitive and pH-sensitive polymers loaded with silver nanoparticles were prepared and evaluated. The nanoparticles were prepared by green synthesis using Agrimonia eupatoria L. extract. According to the data analysis, the in situ gel with the most promising profile contained 15 % of Pluronic® F-127, 0.25 % of methylcellulose, and 0.1 % of Noveon® AA-1. Pluronic® F-127 and methylcellulose significantly increased the viscosity of in situ gels at 37 °C and shear rates similar to speaking and swallowing. At 20 °C, a behavior close to a Newtonian fluid was observed while being easily injectable (injection force 13.455 ±â€¯1.973 N). The viscosity of the formulation increased with temperature and reached 2962.77 ±â€¯63.37 mPa·s (37 °C). A temperature increase led to increased adhesiveness and rigidity of the formulation. The critical sol-gel transition temperature at physiological pH was 32.65 ±â€¯0.35 °C. 96.77 ±â€¯3.26 % of Ag NPs were released by erosion and dissolution of the gel after 40 min. The determination of MIC showed effect against E. coli and S. aureus (0.0625 mM and 0.5000 mM, respectively). The relative inhibition zone diameter of the in situ gel was 73.32 ±â€¯11.06 % compared to gentamicin sulfate. This work discusses the optimization of the formulation of novel antibacterial in situ gel for oromucosal delivery, analyses the impact of the concentration of excipients on the dependent variables, and suggests appropriate evaluation of the formulation in terms of its indication. This study offers a promising dosage form for local treatment of oral diseases.

In Situ Gel with Silver Nanoparticles Prepared Using Agrimonia eupatoria L. Shows Antibacterial Activity.

Silver nanoparticles (Ag NPs) with antibacterial activity can be prepared in different ways. In our case, we used ecological green synthesis with Agrimonia eupatoria L. The plant extract was used with Ag NPs for the first time to prepare termosensitive in situ gels (ISGs). Such gels are used to heal human or animal skin and mucous membranes, as they can change from a liquid to solid state after application. Ag NPs were characterized with various techniques (FTIR, TEM, size distribution, zeta potential) and their antibacterial activity was tested against Staphylococcus aureus and Escherichia coli. In accordance with the TEM data, we prepared monodispersed spherical Ag NPs with an average size of about 20 nm. Organic active compounds from Agrimonia eupatoria L. were found on their surfaces using FTIR spectroscopy. Surprisingly, only the in situ gel with Ag NPs showed antibacterial activity against Escherichia coli, while Ag NPs alone did not. Ag NPs prepared via green synthesis using plants with medicinal properties and incorporated into ISGs have great potential for wound healing due to the antibacterial activity of Ag NPs and the dermatological activity of organic substances from plants.

Microneedles as a perspective for transdermal therapeutic systems.

Transdermal Therapeutic Systems (TTS) improve patient compliance especially due to its simple application and long-term action with the need to exchange the system every 12 hours to several days. The advantages also include elimination of first-pass effect, avoidance of gastrointestinal adverse effects, stable drug levels in the blood and simple discontinuation of therapy by patch removing. However, most drugs do not have the appropriate physicochemical properties to achieve therapeutic levels by transdermal application, therefore only a limited amount of drugs administered by this route is available on the market. Microneedles (MI) by their painless application appear to increase drug permeation when applied transdermally. In this review work, various types of MI (solid, coated, hollow, matrix, hydrogel forming) their size, shape, grouping, but also materials and technologies used in MI production are described. Finally, the work is focused on current clinical trials in which MI have been tested. MI with their unique properties have potential to increase the range of transdermally administered drugs currently applied by another route of administration. MI can simply pave the way for transdermal delivery to poorly penetrating small molecules as well as large molecules such as vaccines, monoclonal antibodies, or siRNA.

Polymorphisms of the XRCC1 and XPD genes and breast cancer risk: a case-control study.

The purpose of this case control study was to evaluate the role of X-ray repair cross-complementing group 1 (XRCC1) and xeroderma pigmentosum group D (XPD) genotypes as genetic indicators of susceptibility to breast cancer (BC). We analysed DNA samples from 114 breast cancer patients and 113 control subjects using polymerase chain reaction-restriction fragment length polymorphism. For the single nucleotide polymorphisms in XRCC1 exon 10 (Arg399Gln, G/A) and XPD exon 23 (Lys751Gln, A/C), no remarkable differences for genotype distribution and allele frequencies were observed between BC group and control group in the study. The genotype frequency for homozygote A/A in XPD exon 6 (Arg156Arg, C/A) were significantly different between BC and control groups (P < 0.0001, odds ratio = 2.14; 95% confidence interval 1.44-3.17). The data indicate a possible role for XPD (Arg156Arg, C/A) polymorphisms in BC susceptibility.