Hyaluronic acid (HA), a major glycosaminoglycan of the extracellular matrix, has cell signaling functions that are dependent on its molecular weight. Anti-inflammatory effects for high-molecular-weight (HMW) HA and pro-inflammatory effects for low-molecular-weight (LMW) HA effects were found for various myeloid cells, including microglia. Astrocytes are cells of ectodermal origin that play a pivotal role in brain inflammation, but the link between HA with different molecular weights and an inflammatory response in these cells is not clear. We tested the effects of LMW and HMW HA in rat primary astrocytes, stimulated with Poly:IC (PIC, TLR3 agonist) and lipopolysaccharide (LPS, TLR4 agonist). Oxylipin profiles were measured by the UPLC-MS/MS analysis and metabolites HDoHEs (from docosahexaenoic acid), -HETEs, prostaglandins (from arachidonic acid), DiHOMEs and HODEs (from linoleic acid) were detected. Both, HMW and LMW HA downregulated the cyclooxygenase-mediated polyunsaturated fatty acids metabolism, LMW also reduced lipoxygenase-mediated fatty acid metabolism. Taken together, the data show that both LMW and HMW (i) influence themselves on cytokines (TNFα, IL-6, IL-10), enzymes iNOS, COX-2, and oxylipin levels in extracellular medium of cultured astrocytes, (ii) induced cellular adaptations in long-term applications, (iii) modulate TLR4- and TLR3-signaling pathways. The effects of HMW and LMW HA are predominantly revealed in TLR4– and TLR3- mediated responses, respectively.

Although many neurological and psychiatric disorders reveal clear sex-dependent variations, the molecular mechanism of this process is not clear enough. Astrocytes are involved in the response of neural tissue to injury and inflammation, produce steroid hormones, and sense steroid presence. To explore the hypothesis that astrocytes may participate in sex-mediated differences of inflammatory responses, we have examined whether male and female primary rat astrocytes show different responses to lipopolysaccharide (LPS) as a toll-like receptor 4 (TLR4) agonist. Levels of mRNA and proteins of tumor necrosis factor alpha (TNFα), interleukin-10 (IL-10), and cyclooxygenase (COX)-2 were assessed using qPCR, immunoblotting, and ELISA. UPLC-MS/MS was used to detect prostaglandins (PGs). LPS stimulation resulted in different levels of cytokine production; more TNFα and less IL-10 were produced in female cells compared with male astrocytes. Although the levels of the COX-2 expression were not altered, LPS significantly induced the synthesis of PGs with notable sex-related differences. PGE2 and PGD2 were less and 6-keto-PGF1α was more upregulated in female astrocytes, and TXB2 had similar levels in cells obtained from males and females. Trilostane, an inhibitor of 3β-Hydroxysteroid dehydrogenase (3β-HSD), inhibited the LPS-induced TNFα production and the release of PGE2, PGD2, and 6-keto-PGF1α in female astrocytes. Thus, male and female astrocytes differentially respond to inflammatory challenges on the level of production of cytokines and steroid hormones. Sex-mediated differences in pro- and anti-inflammatory responses should be taken into consideration for the effective treatment of disorders with neuroinflammation.

Expandable metallic stent placement is often the only way to treat airway obstructions. Such treatment with an uncoated stent causes granulation proliferation and subsequent restenosis, resulting in the procedure’s adverse complications. Systemic administration of steroids drugs in high dosages slows down granulation tissue overgrowth but leads to long-term side effects. Drug-eluting coatings have been used widely in cardiology for many years to suppress local granulation and reduce the organism’s systemic load. Still, so far, there are no available analogs for the trachea. Here, we demonstrate that PLA-, PCL- and PLGA-based films with arrays of microchambers to accommodate therapeutic substances can be used as a drug-eluting coating through securely fixing on the surface of an expandable nitinol stent. PCL and PLA were most resistant to mechanical damage associated with packing in delivery devices and making it possible to keep high-molecular-weight cargo. Low-molecular-weight methylprednisolone sodium succinate is poorly retained in PCL- and PLGA-based microchambers after immersion in deionized water (only 9.5% and 15.7% are left, respectively). In comparison, PLA-based microchambers retain 96.3% after the same procedure. In vivo studies on rabbits have shown that effective granulation tissue suppression is achieved when PLA and PLGA are used for coatings. PLGA-based microchamber coating almost completely degrades in 10 days in the trachea, while PLA-based microchamber films partially preserve their structure. The PCL-based film coating is most stable over time, which probably causes blocking the outflow of fluid from the tracheal mucosa and the aggravation of the inflammatory process against the background of low drug concentration. Combination and variability of polymers in the fabrication of films with microchambers to retain therapeutic compounds are suggested as a novel type of drug-eluting coating.

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In this study, using the Box–Behnken model, we optimized the ethanolic extraction of phytochemicals from Enantia chloranta bark for the first time, assessed the composition with HPLC-MS/MS, performed the green synthesis of silver nanoparticles (AgNPs) and characterized them with UV-Vis spectrophotometry, photon cross-correlation spectroscopy, energy-dispersive X-ray fluorescence spectrometry, and Fourier transform infrared spectroscopy. The antibacterial and antibiotic-resistance reversal properties of optimized extract (O-ECB) and AgNPs were assessed on various microorganisms (15 Gram−, 7 Gram+, and 2 fungi) using the well diffusion method and microbroth dilution assay. The mechanism of action was investigated on growth kinetic and proton pumps of Escherichia coli. The in vivo antimicrobial activity and toxicity were assessed on Galleria mellonella larvae. The optimal mass yield (14.3%) related to the highest antibacterial activity (31 mm vs. S. aureus ATCC 6538) was obtained with the following operating conditions: % EtOH—100%; ratio m/v—20 g/mL; and extraction time—6 h. All the compounds identified in O-ECB were alkaloids and the major constituents were palmatine (51.63%), columbamine +7,8-dihydro-8-hydroxypalmatine (19.21%), jatrorrhizine (11.02%), and pseudocolumbamine (6.33%). Among the minerals found in O-ECB (S, Si, Cl, K, Ca, Mn, Fe, Zn, and Br), Br, Fe, and Cl were the most abundant with mean fluorescence intensities of 4.6529, 3.485,4, and 2.5942 cps/uA, respectively. The synthesized AgNPs revealed a strong absorption plasmon band between 430 and 450 nm and an average hydrodynamic diameter ×50 of 59.74 nm, and the presence of Ag was confirmed by a characteristic peak in the spectrum at the silver Kα line of 22.105 keV. Both O-ECB and AgNPs displayed noteworthy and broad-spectrum antimicrobial activities against 20/24 and 24/24 studied microorganisms, respectively, with recorded minimal inhibitory concentrations (MICs) ranging from 8 to ≥ 1024 µg/mL and 2 to 64 µg/mL. O-ECB and AgNPs showed antibiofilm properties and significantly enhanced the efficacy of conventional antibiotics against selected multidrug-resistant bacteria, and the mechanistic investigations revealed their interference with bacterial growth kinetic and the inhibition of H+-ATPase proton pumps. LD50s were 40 mg/mL and 0.6 mg/mL for O-ECB and AgNPs, respectively. In conclusion, the current study provides a strong experimental baseline to consider Enantia chlorantha bark and their green synthetized AgNPs as potent antimicrobial compounds in this era of antimicrobial resistance.