Examination of the exposome in an animal model: The impact of high fat diet and rat strain on local and systemic immune markers following occupational welding fume exposure

The goal of this study was to investigate the impact of multiple exposomal factors (genetics, lifestyle factors, environmental/occupational exposures) on pulmonary inflammation and corresponding alterations in local/systemic immune parameters. Accordingly, male Sprague-Dawley (SD) and Brown Norway (BN) rats were maintained on either regular (Reg) or high fat (HF) diets for 24wk. Welding fume (WF) exposure (inhalation) occurred between 7 and 12wk. Rats were euthanized at 7, 12, and 24wk to evaluate local and systemic immune markers corresponding to the baseline, exposure, and recovery phases of the study, respectively. At 7wk, HF-fed animals exhibited several immune alterations (blood leukocyte/neutrophil number, lymph node B-cell proportionality)-effects which were more pronounced in SD rats. Indices of lung injury/inflammation were elevated in all WF-exposed animals at 12wk; however, diet appeared to preferentially impact SD rats at this time point, as several inflammatory markers (lymph node cellularity, lung neutrophils) were further elevated in HF over Reg animals. Overall, SD rats exhibited the greatest capacity for recovery by 24wk. In BN rats, resolution of immune alterations was further compromised by HF diet, as many exposure-induced alterations in local/systemic immune markers were still evident in HF/WF animals at 24wk. Collectively, HF diet appeared to have a greater impact on global immune status and exposure-induced lung injury in SD rats, but a more pronounced effect on inflammation resolution in BN rats. These results illustrate the combined impact of genetic, lifestyle, and environmental factors in modulating immunological responsivity and emphasize the importance of the exposome in shaping biological responses.

Antidiabetic Activity of Momordica charantia L. and Mechanism of Insulin Secretion of 1-Butanol Soluble Part on Type 2 Diabetic Model Rats

The in vivo effects of fruit pulp juice (MC-PJ) of Momordica charantia and its 1-butanol soluble part (MC-BP) and aqueous soluble part (MC-AP) on blood glucose of type 2 diabetic rats were studied. In vitro insulin secretion in response to MC-BP and MC-AP from whole perfused pancreas was measured. For elucidating the mechanism of insulinotropic action, the insulin secretory activity of MC-BP in the presence of 11 mM glucose, 50 μM verapamil (Ca++ channel blocker), 8 mM diazoxide (K+ ATP channel opener) and 10 mM theophylline (cAMP phosphodiesterase inhibitor) were studied. Serum glucose was measured by glucose oxidase-peroxidase method and rat insulin was assayed by specific ELISA. In the in vivo study, MC-BP significantly opposed the rise of serum glucose compared to control at 105 min (p<0.05). Although the MC-AP and MC-PJ lowered the serum glucose both at 60 and 105 min, these were not statistically significant. In the in vitro study, only MC-BP produced 22-fold increase in insulin secretion from the perfused pancreas at nonstimulatory glucose level, which was significant (basal vs. MC-BP, 0.071±0.009 vs. 1.563±0.150 ng/ml, p<0.001). The MC-BP also enhanced the insulin secretion from the glucose-stimulated pancreas (p<0.001). The MC-BP induced insulin secretion was not affected in presence of diazoxide and verapamil. The obtained results also showed that MC-BP enhanced the insulin secretory effect of theophylline (p<0.001). The findings indicate that MC-BP has stimulatory effects on physiological pathways of insulin secretion which may underlie its reported antidiabetic action. Dhaka Univ. J. Pharm. Sci. 19(2): 111-117, 2020 (December)

Scaffold of Selenium Nanovectors and Honey Phytochemicals for Inhibition of Pseudomonas aeruginosa Quorum Sensing and Biofilm Formation

Honey is an excellent source of polyphenolic compounds that are effective in attenuating quorum sensing (QS), a chemical process of cell-to-cell communication system used by the opportunistic pathogen Pseudomonas aeruginosa to regulate virulence and biofilm formation. However, lower water solubility and inadequate bioavailability remains major concerns of these therapeutic polyphenols. Its therapeutic index can be improved by using nano-carrier systems to target QS signaling potently. In the present study, we fabricated a unique drug delivery system comprising selenium nanoparticles (SeNPs; non-viral vectors) and polyphenols of honey (HP) for enhancement of anti-QS activity of HP against P. aeruginosa PAO1. The developed selenium nano-scaffold showed superior anti-QS activity, anti-biofilm efficacy, and anti-virulence potential in both in-vitro and in-vivo over its individual components, SeNPs and HP. LasR is inhibited by selenium nano-scaffold in-vitro. Using computational molecular docking studies, we have also demonstrated that the anti-virulence activity of selenium nano-scaffold is reliant on molecular binding that occurs between HP and the QS receptor LasR through hydrogen bonding and hydrophobic interactions. Our preliminary investigations with selenium-based nano-carriers hold significant promise to improve anti-virulence effectiveness of phytochemicals by enhancing effective intracellular delivery.

Metal chelator combined with permeability enhancer ameliorates oxidative stress-associated neurodegeneration in rat eyes with elevated intraocular pressure

Because as many as half of glaucoma patients on intraocular pressure (IOP)-lowering therapy continue to experience optic nerve toxicity, it is imperative to find other effective therapies. Iron and calcium ions play key roles in oxidative stress, a hallmark of glaucoma. Therefore, we tested metal chelation by means of ethylenediaminetetraacetic acid (EDTA) combined with the permeability enhancer methylsulfonylmethane (MSM) applied topically on the eye to determine if this noninvasive treatment is neuroprotective in rat optic nerve and retinal ganglion cells exposed to oxidative stress induced by elevated IOP. Hyaluronic acid (HA) was injected into the anterior chamber of the rat eye to elevate the IOP. EDTA-MSM was applied topically to the eye for 3 months. Eyeballs and optic nerves were processed for histological assessment of cytoarchitecture. Protein-lipid aldehyde adducts and cyclooxygenase-2 (COX-2) were detected immunohistochemically. HA administration increased IOP and associated oxidative stress and inflammation. Elevated IOP was not affected by EDTA-MSM treatment. However, oxidative damage and inflammation were ameliorated as reflected by a decrease in formation of protein-lipid aldehyde adducts and COX-2 expression, respectively. Furthermore, EDTA-MSM treatment increased retinal ganglion cell survival and decreased demyelination of optic nerve compared with untreated eyes. Chelation treatment with EDTA-MSM ameliorates sequelae of IOP-induced toxicity without affecting IOP. Because most current therapies aim at reducing IOP and damage occurs even in the absence of elevated IOP, EDTA-MSM has the potential to work in conjunction with pressure-reducing therapies to alleviate damage to the optic nerve and retinal ganglion cells.

Overexpression of aldehyde dehydrogenase 1A1 reduces oxidation-induced toxicity in SH-SY5Y neuroblastoma cells

Oxidative stress leading to lipid peroxidation is a problem in neurodegenerative diseases, because the brain is rich in polyunsaturated fatty acids and low in endogenous antioxidants. One of the most toxic byproducts of lipid peroxidation, 4-hydroxynonenal (HNE), is implicated in oxidative stress-induced damage in neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS). In this study, the human neuroblastoma cell line SH-SY5Y was used to test the protective effects of increasing the detoxification of HNE by overexpressing the HNE-detoxifying enzyme aldehyde dehydrogenase 1A1 (ALDH1). Overexpression of ALDH1 in the SH-SY5Y cells acts to reduce production of protein-HNE adducts and activation of caspase-3. Our data suggest that detoxification of HNE could be therapeutic in preventing some of the toxic disruptions of the brain's redox systems found in many neurodegenerative diseases.

Acute sensorineural hearing loss immediately following a local anaesthetic dental procedure

Acute sensorineural hearing loss is an uncommon phenomenon. We describe the first case of a 42-year-old lady who presented with acute sensorineural hearing loss occurring immediately after a dental procedure. Possible mechanisms are discussed. She was treated with high dose oral steroids, low molecular weight dextran and vasodilators with benefit.

Identification of lymphocyte subsets in pregnancy gingivitis

The percentage of gingival tissue and peripheral T, T Subsets and B lymphocytes were assessed in ten pregnant women during the first, second and third trimesters. Clinically the gingival index (GI) was found to be higher during pregnancy than in the control group. The percentage of the T3, T4 and B cells appeared to decrease in peripheral blood and gingival tissues during pregnancy as compared to control group.

Prepubertal periodontitis: a genetic analysis

Genetic factors were recognized as possible predisposing factors in the etiopathogenesis of prepubertal periodontitis (PP). Consequently, the present work was carried out to determine the possible mode of inheritance and if there were any associated chromosomal aberrations in cases with PP. The study included 3 families with probands manifesting PP (the families included 18 individuals). Pedigree analysis was carried out as well as chromosomal analysis. The results pointed out to the possibility of new mutations arising due to various environmental factors (including the use of pesticides and their handling), in addition to a possible autosomal recessive inheritance. Chromosomal analysis showed no association between a certain chromosomal aberration and PP. An interesting finding was that a girl proband proved to be Xo female, i.e. a case of Turner's syndrome. This could be considered the first report of Turner's syndrome with PP.