HEPATOCYTE APOPTOSIS INDUCTION BY ACETAMINOPHEN THROUGH MODULATION OF CASPASE/BAX PATHWAY IN MICE

Objective: Acetaminophen (APAP) overdose contributes to liver damage through modulation of pro-apoptotic processing. This study evaluated the involvement of caspase/Bax factors in APAP hepatotoxicity in vivo and in vitro. Methods: The involvement of caspase/Bax factors in APAP hepatotoxicity was evaluated in BALB/c mice and on isolated primary mouse hepatocytes. In vitro MTT assay was carried out on primary cultured mouse hepatocytes treated with APAP (2.5, 5, 10 mmol) and Annexin V/PI staining was employed to cell suspension for imaging under fluorescence microscopy. In addition, caspase-3 concentrations were determined in cell lysates. In vivo, mice were treated with a toxic dose of APAP (700 mg/kg) and immunodetection of Bax was made by Western Blot. Vitamin C (Vit C) was used as a hepato-protectant due to its known antioxidant activities. Results: In vitro dose-dependent increase in mitochondrial electron transport capacity was evident in isolated mouse primary hepatocytes incubated with the high dose of APAP (10 mmol) compared to both nontreated cells and cells pre-treated with Vitamin C (Vit C) (0.5 mmol) (p<0.05). Apoptosis was confirmed in hepatocytes through Annexin V staining after APAP treatment and the signal was reduced when hepatocytes were pre-treated with Vit C. In addition, caspase-3 concentration was decreased in cells pretreated with Vit C prior to APAP exposure. In vivo, Bax immunodetection utilizing western blotting was increased in mice treated with the toxic dose of APAP (700 mg/kg) and attenuated through pre-treatment with Vit C. Conclusion: Modulation of apoptotic caspase/Bax pathway is present in hepatocytes undergoing APAP-induced toxicity

Influence of Molecular Weight and Degree of Deacetylation of Low Molecular Weight Chitosan on the Bioactivity of Oral Insulin Preparations

The objective of the present study was to prepare and characterize low molecular weight chitosan (LMWC) with different molecular weight and degrees of deacetylation (DDA) and to optimize their use in oral insulin nano delivery systems. Water in oil nanosized systems containing LMWC-insulin polyelectrolyte complexes were constructed and their ability to reduce blood glucose was assessed in vivo on diabetic rats. Upon acid depolymerization and testing by viscosity method, three molecular weights of LMWC namely, 1.3, 13 and 18 kDa were obtained. As for the DDA, three LMWCs of 55%, 80% and 100% DDA were prepared and characterized by spectroscopic methods for each molecular weight. The obtained LMWCs showed different morphological and in silico patterns. Following complexation of LMWCs with insulin, different aggregation sizes were obtained. Moreover, the in vivo tested formulations showed different activities of blood glucose reduction. The highest glucose reduction was achieved with 1.3 kDa LMWC of 55% DDA. The current study emphasizes the importance of optimizing the molecular weight along with the DDA of the incorporated LMWC in oral insulin delivery preparations in order to ensure the highest performance of such delivery systems

Bioadhesive Controlled Metronidazole Release Matrix Based on Chitosan and Xanthan Gum

Metronidazole, a common antibacterial drug, was incorporated into a hydrophilic polymer matrix composed of chitosan xanthan gum mixture. Hydrogel formation of this binary chitosan-xanthan gum combination was tested for its ability to control the release of metronidazole as a drug model. This preparation (MZ-CR) was characterized by in vitro, ex vivo bioadhesion and in vivo bioavailability study. For comparison purposes a commercial extended release formulation of metronidazole (CMZ) was used as a reference. The in vitro drug-release profiles of metronidazole preparation and CMZ were similar in 0.1 M HCl and phosphate buffer pH 6.8. Moreover, metronidazole preparation and CMZ showed a similar detachment force to sheep stomach mucosa, while the bioadhesion of the metronidazole preparation was higher three times than CMZ to sheep duodenum. The results of in vivo study indicated that the absorption of metronidazole from the preparation was faster than that of CMZ. Also, MZ-CR leads to higher metronidazole Cmax and AUC relative to that of the CMZ. This increase in bioavailability might be explained by the bioadhesion of the preparation at the upper part of the small intestine that could result in an increase in the overall intestinal transit time. As a conclusion, formulating chitosan-xanthan gum mixture as a hydrophilic polymer matrix resulted in a superior pharmacokinetic parameters translated by better rate and extent of absorption of metronidazole

Plasma concentrations of 25-hydroxyvitamin D among Jordanians: Effect of biological and habitual factors on vitamin D status

<p>Abstract</p> <p>Background</p> <p>Vitamin D is cutaneously synthesized following sun exposure (vitamin D₃) as well as it is derived from dietary intake (vitamin D₃and D₂). Vitamin D₂and D₃are metabolized in the liver to 25-hydroxyvitamin D (25(OH)D). This metabolite is considered the functional indicator of vitamin D stores in humans. Since Jordan latitude is 31°N, cutaneous synthesis of vitamin D₃should be sufficient all year round. However, many indications reveal that it is not the case. Thus, this study was conducted to determine the 25(OH)D status among Jordanians.</p> <p>Methods</p> <p>Three hundred healthy volunteers were enrolled in a cross sectional study; 201 females and 99 males. 25(OH)D and calcium concentrations were measured by enzyme linked immunosorbent assay and spectroscopy techniques, respectively. All participants filled a study questionnaire that covered age, sex, height, weight, diet, and dress style for females. Females were divided according to their dress style: Western style, Hijab (all body parts are covered except the face and hands), and Niqab (all body parts are covered including face and hands).</p> <p>Results</p> <p>The average plasma 25(OH)D levels in males and females were 44.5 ± 10.0 nmol/l and 31.1 ± 12.0 nmol/l, respectively. However, when female 25(OH)D levels were categorized according to dress styles, the averages became 40.3, 31.3 and 28.5 nmol/l for the Western style, Hijab and Niqab groups, respectively. These 25(OH)D levels were significantly less than those of males (p < 0.05, 0.001, 0.001, respectively). In addition, the plasma 25(OH)D levels of the Western style group was significantly higher than those of Hijab and Niqab groups (p < 0.001). Furthermore, dairy consumption in males was a positive significant factor in vitamin D status. Even though calcium concentrations were within the reference range, the Hijab and Niqab-dressed females have significantly less plasma calcium levels than males (p < 0.01).</p> <p>Conclusions</p> <p>Very low plasma 25(OH)D levels in females wearing Hijab or Niqab are highly attributed to low sunlight or UVB exposure. In addition, most of males (76%) and Western style dressed females (90%) have 25(OH)D concentrations below the international recommended values (50 nmol/l), suggesting that although sun exposure should be enough, other factors do play a role in these low concentrations. These findings emphasize the importance of vitamin D supplementation especially among conservatively dressed females, and determining if single nucleotide polymorphisms of the genes involved in vitamin D metabolism do exist among Jordanians.</p

Preclinical and pharmacological investigations of ordonafil, a novel phosphodiesterase-5 inhibitor for the treatment of erectile dysfunction

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Tailored on demand anti-coagulant dosing: An in vitro and in vivo evaluation of 3D printed purpose-designed oral dosage forms

Coumarin therapy has been associated with high levels of inter- and intra-individual variation in the required dose to reach a therapeutic anticoagulation outcome. Therefore, a dynamic system that is able to achieve accurate delivery of a warfarin dose is of significant importance. Here we assess the ability of 3D printing to fabricate and deliver tailored individualised precision dosing using in-vitro and in-vivo models. Sodium warfarin loaded filaments were compounded using hot melt extrusion (HME) and further fabricated via fused deposition modelling (FDM) 3D printing to produce capsular-ovoid-shaped dosage forms loaded at 200 or 400 µg dose. The solid dosage forms and comparator warfarin aqueous solutions were administered by oral gavage to Sprague–Dawley rats. A novel UV imaging approach indicated that the erosion of the methacrylate matrix was at a rate of 16.4 and 15.2 µm/min for horizontal and vertical planes respectively. In vivo, 3D printed forms were as proportionately effective as their comparative solution form in doubling plasma exposure following a doubling of warfarin dose (184% versus 192% respectively). The 3D printed ovoids showed a lower Cmax of warfarin (1.51 and 3.33 mg/mL versus 2.5 and 6.44 mg/mL) and a longer Tmax (6 and 3.7 versus 4 and 1.5 h) in comparison to liquid formulation. This work demonstrates for the first time in vivo, the potential of FDM 3D printing to produce a tailored specific dosage form and to accurately titrate coumarin dose response to an individual patient

<it>Eriobotrya japonica </it>hydrophilic extract modulates cytokines in normal tissues, in the tumor of Meth-A-fibrosarcoma bearing mice, and enhances their survival time

Abstract Background Cytokines play a key role in the immune response to developing tumors, and therefore modulating their levels and actions provides innovative strategies for enhancing the activity of antigen presenting cells and polarizing towards T helper 1 type response within tumor microenvironment. One of these approaches could be the employment of plant extracts that have cytokine immunomodulation capabilities. Previously, we have shown that the Eriobotrya japonica hydrophilic extract (EJHE) induces proinflammatory cytokines in vitro and in vivo. Methods The present study explored the in vivo immunomodulatory effect on interferon-gamma (IFN-γ), interleukin-17 (IL-17), and transforming growth factor-beta 1 (TGF-β1) evoked by two water-extracts prepared from EJ leaves in the tissues of normal and Meth-A-fibrosarcoma bearing mice. Results Intraperitoneal (i.p.) administration of 10 μg of EJHE and EJHE-water residue (WR), prepared from butanol extraction, increased significantly IFN-γ production in the spleen (p Conclusions The therapeutic value of EJHE-WR as an anticancer agent merits further investigation of understanding the effect of immunomodulators' constituents on the cellular components of the tissue microenvironment. This can lead to the development of improved strategies for cancer treatment and thus opening up a new frontier for future studies.</p