Synergistic Effect of Nilavembu Choornam-Gold Nanoparticles on Antibiotic-Resistant Bacterial Susceptibility and Contact Lens Contamination-Associated Infectious Pathogenicity.

Antibiotic-resistant bacterial colonies mitigate rapid biofilm formation and have complex cell wall fabrications, making it challenging to penetrate drugs across their biofilm barriers. The objective of this study was to investigate the antibacterial susceptibility of antibiotic-resistant bacteria and contact lens barrenness. Nilavembu Choornam-Gold Nanoparticles (NC-GNPs) were synthesized using NC polyherbal extract and characterized by UV-visible spectrophotometer, SEM-EDX, XRD, Zeta sizer, FTIR, and TEM analysis. Contact lenses with overnight cultures of antibiotic-resistant bacteria K. pneumoniae and S. aureus showed significant differences in growth, biofilm formation, and infection pathogenicity. The NC-GNPs were observed in terms of size (average size is 57.6 nm) and surface chemistry. A zone of inhibition was calculated for K. pneumoniae 18.8 ± 1.06, S. aureus 23.6 ± 1.15, P. aeruginosa 24.16 ± 0.87, and E. faecalis 24.5 ± 1.54 mm at 24 h of NC-GNPs alone treatment. In electron microscopy studies, NC-GNP-treated groups showed nuclear shrinkage, nuclear disintegration, degeneration of cell walls, and inhibited chromosomal division. In contrast, normal bacterial colonies had a higher number of cell divisions and routinely migrated toward cell multiplications. NC-GNPs exhibited antibacterial efficacy against antibiotic-resistant bacteria when compared to NC extract alone. We suggest that NC-GNPs are highly valuable to the population of hospitalized patients and other people to reduce the primary complications of contact lens contamination-oriented microbial infection and the therapeutic efficiency of antibiotic-resistant bacterial pathogenicity.

Genetic Disruption of Guanylyl Cyclase/Natriuretic Peptide Receptor-A Triggers Differential Cardiac Fibrosis and Disorders in Male and Female Mutant Mice: Role of TGF-ß1/SMAD Signaling Pathway.

The global targeted disruption of the natriuretic peptide receptor-A (NPRA) gene (Npr1) in mice provokes hypertension and cardiovascular dysfunction. The objective of this study was to determine the mechanisms regulating the development of cardiac fibrosis and dysfunction in Npr1 mutant mice. Npr1 knockout (Npr1-/-, 0-copy), heterozygous (Npr1+/-, 1-copy), and wild-type (Npr1+/+, 2-copy) mice were treated with the transforming growth factor (TGF)-ß1 receptor (TGF-ß1R) antagonist GW788388 (2 µg/g body weight/day; ip) for 28 days. Hearts were isolated and used for real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR), Western blot, and immunohistochemical analyses. The Npr1-/- (0-copy) mice showed a 6-fold induction of cardiac fibrosis and dysfunction with markedly induced expressions of collagen-1α (3.8-fold), monocyte chemoattractant protein (3.7-fold), connective tissue growth factor (CTGF, 5.3-fold), α-smooth muscle actin (α-SMA, 6.1-fold), TGF-ßRI (4.3-fold), TGF-ßRII (4.7-fold), and phosphorylated small mothers against decapentaplegic (pSMAD) proteins, including pSMAD-2 (3.2-fold) and pSMAD-3 (3.7-fold), compared with wild-type mice. The expressions of phosphorylated extracellular-regulated kinase ERK1/2 (pERK1/2), matrix metalloproteinases-2, -9, (MMP-2, -9), and proliferating cell nuclear antigen (PCNA) were also significantly upregulated in Npr1 0-copy mice. The treatment of mutant mice with GW788388 significantly blocked the expression of fibrotic markers, SMAD proteins, MMPs, and PCNA compared with the vehicle-treated control mice. The treatment with GW788388 significantly prevented cardiac dysfunctions in a sex-dependent manner in Npr1 0-copy and 1-copy mutant mice. The results suggest that the development of cardiac fibrosis and dysfunction in mutant mice is predominantly regulated through the TGF-ß1-mediated SMAD-dependent pathway.

Umbelliferone modulates gamma-radiation induced reactive oxygen species generation and subsequent oxidative damage in human blood lymphocytes.

The purpose of this study was to investigate the antioxidant potential of umbelliferone, 7-hydroxy coumarin, and its role in the protection against radiation-induced oxidative damage in cultured human blood lymphocytes. It was found that the antioxidant effect of umbelliferone was dose dependent in hydroxyl (OH(•)), superoxide anion (O(2)(•-)), 2,2-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid radical cation (ABTS(•+)) and 1,1-diphenyl-2-picrylhydrazyl (DPPH(•)) radical scavenging assays. To explore the radioprotective effect of umbelliferone, freshly isolated human blood lymphocytes were treated with 124 µM umbelliferone (optimum dose-fixed by MTT assay) 30 min before 3Gy irradiation. It was found that umbelliferone pretreatment inhibited radiation-induced reactive oxygen species generation in 3Gy exposed lymphocytes. Microscopic observations showed that there was a significant apoptotic cells (ethidium bromide/acridine orange staining) and decreased mitochondrial membrane potential (Rhodamine 123 staining) in irradiated lymphocytes. On the other hand, 124 µM umbelliferone treatment significantly decreased % of apoptotic cells and prevented radiation induced mitochondrial depolarization in lymphocytes. Further, it was noticed that there was an increased DNA damage (comet assay), lipid peroxidation with decreased antioxidant enzymatic i.e., superoxide dismutase, catalase and, glutathione peroxidase activities in 3Gy irradiated lymphocytes. Conversely, umbelliferone (124 µM) treatment before irradiation decreased comet attributes and lipid peroxidative markers with improved antioxidant enzyme activities in irradiated lymphocytes. Taken together, the results of this study clearly suggest the radioprotective effect of umbelliferone in human lymphocytes by inhibiting reactive oxygen species generation and its subsequent toxicity.

Caffeic acid modulates ultraviolet radiation-B induced oxidative damage in human blood lymphocytes.

Ultraviolet (UV) radiation causes inflammation, gene mutation and immunosuppressin in the human skin cells. These biological changes are responsible for photocarcinogenesis and photoaging. Normal lymphocytes are highly sensitive to the damaging effect of UV-radiation and undergo cell death. In the present study, the photoprotective effect of caffeic acid (3,4-dihydroxy cinnamic acid), a dietary phenolic compound, has been examined in the UVB (280-320) irradiated human blood lymphocytes. Lymphocytes pretreated with increasing concentration of caffeic acid (l, 5 and 10 microg/mL) for 30min were irradiated and lipid peroxidation, antioxidant defence status, cell viability (by MTT assay) and DNA damage (by comet assay) were examined. UVB-irradiation causes increased levels of lipid peroxidation, DNA damage and decreased antioxidant status, cell viability in human lymphocytes. Caffeic acid pretreatment significantly reduced the levels of lipid peroxidation markers i.e. thiobarbituric acid reactive substance (TBARS), lipid hydroperoxide (LPH), conjugated diene (CD) and decreased DNA damage (tail length and % tail DNA) in UVB-irradiated lymphocytes. Further, caffeic acid pretreatment significantly maintains antioxidant status and decreased UVB-induced cytotoxicity. The maximum dose of caffeic acid (l0 microg/mL) normalized the UVB induced cellular changes indicating the photoprotective effect of caffeic acid in irradiated lymphocytes.