Effect of ketorolac and diclofenac on the impairment of endothelium-dependent relaxation induced by reactive oxygen species in rabbit abdominal aorta

Thermo-Responsive PLGA-PEG-PLGA Hydrogels as Novel Injectable Platforms for Neuroprotective Combined Therapies in the Treatment of Retinal Degenerative Diseases

The present study aims to develop a thermo-responsive-injectable hydrogel (HyG) based on PLGA-PEG-PLGA (PLGA = poly-(DL-lactic acid co-glycolic acid); PEG = polyethylene glycol) to deliver neuroprotective agents to the retina over time. Two PLGA-PEG PLGA copolymers with different PEG:LA:GA ratios (1:1.54:23.1 and 1:2.25:22.5) for HyG-1 and HyG-2 development respectively were synthetized and characterized by different techniques (gel permeation chromatography (GPC), nuclear magnetic resonance (NMR), dynamic light scattering (DLS), critical micelle concentration (CMC), gelation and rheological behaviour). According to the physicochemical characterization, HyG-1 was selected for further studies and loaded with anti-inflammatory drugs: dexamethasone (0.2%), and ketorolac (0.5%), alone or in combination with the antioxidants idebenone (1 µM) and D-α-Tocopherol polyethylene glycol 1000 succinate (TPGS) (0.002%). In vitro drug release and cytotoxicity studies were performed for the active substances and hydrogels (loaded and drug-free). A cellular model based on oxidative stress was optimized for anti-inflammatory and antioxidant screening of the formulations by using retinal-pigmented epithelial cell line hTERT (RPE-1). The copolymer 1, used to prepare thermo-responsive HyG-1, showed low polydispersity (PDI = 1.22) and a strong gel behaviour at 25% (w/v) in an isotonic buffer solution close to the vitreous temperature (31-34 °C). Sustained release of dexamethasone and ketorolac was achieved between 47 and 62 days, depending on the composition. HyG-1 was well tolerated (84.5 ± 3.2%) in retinal cells, with values near 100% when the anti-inflammatory and antioxidant agents were included. The combination of idebenone and dexamethasone promoted high oxidative protection in the cells exposed to H2O2, with viability values of 86.2 ± 14.7%. Ketorolac and dexamethasone-based formulations ameliorated the production of TNF-α, showing significant results (p ≤ 0.0001). The hydrogels developed in the present study entail a novel biodegradable tool to treat neurodegenerative processes of the retina overtime.

Diclofenac but not celecoxib improves endothelial function in rheumatoid arthritis: A study in adjuvant-induced arthritis

BACKGROUND AND AIMS

We aimed at investigating the effect of celecoxib (COX-2 selective inhibitor) and diclofenac (non-selective COX inhibitor) on endothelial function, and at identifying the underlying mechanisms in adjuvant-induced arthritis (AIA).

METHODS

At the first signs of AIA, diclofenac (5 mg/kg twice a day, i.p), celecoxib (3 mg/kg/day, i.p) or saline (Vehicle) was administered for 3 weeks. Endothelial function was studied in aortic rings relaxed with acetylcholine (Ach) with or without inhibitors of NOS, arginase, EDHF and superoxide anions (O₂^-°) production. Aortic expression of eNOS, Ser1177-phospho-eNOS, COX-2, arginase-2, p22^phox and p47^phox was evaluated by Western blotting analysis. Arthritis scores, blood pressure, glycaemia and serum ADMA levels were measured.

RESULTS

Diclofenac and celecoxib significantly reduced arthritis score to the same extent (p<0.05). As compared to vehicle-treated AIA, celecoxib did not change whereas diclofenac improved endothelial function (p<0.05) through increased EDHF production, decreased arginase activity and expression, decreased superoxide anions production and expression of p22^phox and p47^phox. Diclofenac but not celecoxib significantly enhanced blood pressure and serum ADMA levels. Glycaemia was unchanged by both treatments.

CONCLUSIONS

Our study reveals that the effect of NSAIDs on endothelial function cannot be extrapolated from their impact on arthritis severity and suggest that changes in blood pressure and plasma ADMA levels may not be useful to predict CV risk of NSAIDs in RA.

High Performance Liquid Chromatography-mass Spectrometry Analysis of High Antioxidant Australian Fruits with Antiproliferative Activity Against Cancer Cells

BACKGROUND

High antioxidant capacities have been linked to the treatment and prevention of several cancers. Recent reports have identified several native Australian fruits with high antioxidant capacities. Despite this, several of these species are yet to be tested for anticancer activity.

MATERIALS AND METHODS

Solvent extracts prepared from high antioxidant native Australian fruits were analyzed for antioxidant capacity by the di (phenyl)-(2,4,6-trinitrophenyl) iminoazanium free radical scavenging assay. Antiproliferative activities against CaCo2 and HeLa cancer cells were determined by a multicellular tumor spheroid-based cell proliferation assay. Toxicity was determined by Artemia franciscana bioassay.

RESULTS

Methanolic extracts of all plant species displayed high antioxidant contents (equivalent to approximately 7-16 mg of vitamin C per gram of fruit extracted). Most aqueous extracts also contained relatively high antioxidant capacities. In contrast, the ethyl acetate, chloroform, and hexane extracts of most species (except lemon aspen and bush tomato) had lower antioxidant contents (below 1.5 mg of vitamin C equivalents per gram of plant material extracted). The antioxidant contents correlated with the ability of the extracts to inhibit proliferation of CaCo2 and HeLa cancer cell lines. The high antioxidant methanolic extracts of all species were potent inhibitors of cell proliferation. The methanolic lemon aspen extract was particularly effective, with IC50 values of 480 and 769 μg/mL against HeLa and CaCo2 cells, respectively. In contrast, the lower antioxidant ethyl acetate and hexane extracts (except the lemon aspen ethyl acetate extract) generally did not inhibit cancer cell proliferation or inhibited to only a minor degree. Indeed, most of the ethyl acetate and hexane extracts induced potent cell proliferation. The native tamarind ethyl acetate extract displayed low-moderate toxicity in the A. franciscana bioassay (LC50 values below 1000 μg/mL). All other extracts were nontoxic. A total of 145 unique mass signals were detected in the lemon aspen methanolic and aqueous extracts by nonbiased high-performance liquid chromatography-mass spectrometry analysis. Of these, 20 compounds were identified as being of particular interest due to their reported antioxidant and/or anticancer activities.

CONCLUSIONS

The lack of toxicity and antiproliferative activity of the high antioxidant plant extracts against HeLa and CaCo2 cancer cell lines indicates their potential in the treatment and prevention of some cancers.

SUMMARY

Australian fruit extracts with high antioxidant contents were potent inhibitors of CaCo2 and HeLa carcinoma cell proliferationMethanolic lemon aspen extract was particularly potent, with IC50 values of 480 μg/mL (HeLa) and 769 μg/mL (CaCo2)High-performance liquid chromatography-mass spectrometry-quadrupole time-of-flight analysis highlighted and putatively identified 20 compounds in the antiproliferative lemon aspen extractsIn contrast, lower antioxidant content extracts stimulated carcinoma cell proliferationAll extracts with antiproliferative activity were nontoxic in the Artemia nauplii assay. Abbreviations used: DPPH: di (phenyl)- (2,4,6-trinitrophenyl) iminoazanium, HPLC: High-performance liquid chromatography, IC50: The concentration required to inhibit by 50%, LC50: The concentration required to achieve 50% mortality, MS: Mass spectrometry.

The effect of ketorolac tromethamine, methylprednisolone, and platelet-rich plasma on human chondrocyte and tenocyte viability

PURPOSE

The purpose of this study was to evaluate the effect on cell viability of the isolated and combined use of allogeneic platelet-rich plasma (PRP) and ketorolac tromethamine on human chondrocytes and tenocytes in a highly controlled in vitro environment.

METHODS

PRP was produced from 8 subjects. Human chondrocytes (Lonza, Hopkinton, MA) and tenocytes isolated from samples of the long head of the biceps tendons were treated in culture with PRP, ketorolac tromethamine, and methylprednisolone, both alone and in combination. Control samples were treated in media containing 2% or 10% fetal bovine serum (FBS). Cells were exposed for 1 hour. Luminescence assays were obtained to examine cell viability after 24 hours and long-term effects on cell viability after 120 hours. Radioactive thymidine assay was used to measure proliferation after 120 hours.

RESULTS

For chondrocytes, cell viability (120 hours) increased significantly with the treatment of PRP alone (43,949 ± 28,104 cells; P < .001) and with the combination of ketorolac tromethamine and PRP (43,276 ± 31,208; P < .001), compared with the 2% FBS group (7,397 ± 470). Cell viability decreased significantly after exposure to methylprednisolone (1,323 ± 776; P < .001) and its combination with PRP (4,381 ± 5,116; p < .001). For tenocytes, cell viability (120 hours) was significantly higher with the treatment of PRP (61,287 ± 23,273; P < .001) and the combined treatment of ketorolac tromethamine and PRP (52,025 ± 17,307; P < .001), compared with the 2% FBS group (23,042 ± 2,973). Cell viability decreased significantly after exposure to methylprednisolone (3,934 ± 1,791; P = .001) and its combination with PRP (5,201 ± 2,834; P = .003), compared with 2% FBS.

CONCLUSIONS

Tendon and cartilage cells showed increased cell viability after an exposure to allogeneic PRP and ketorolac tromethamine. Exposure to methylprednisolone alone decreased cell viability, and addition of PRP could partially reverse this negative effect.

CLINICAL RELEVANCE

Intra-articular injections of pain-modifying or anti-inflammatory drugs are routinely given in orthopaedic practice. Among the many agents available for intra-articular injection, corticosteroids and local anesthetics are the most common in clinical practice. Potential detrimental side effects of intra-articular injections of corticosteroids and local anesthetics have prompted investigation into alternative treatment options such as combinations of PRP and ketorolac tromethamine. In vitro evaluation of their effect on cell viability might build a basis for further translational research and clinical application.

Prevalence and risk factors of asymptomatic peripheral arterial disease in patients with COPD in Taiwan

AIM

Chronic obstructive pulmonary disease (COPD) is an independent risk factor for cardiovascular morbidity and mortality. The aim of this study was to determine the prevalence of asymptomatic peripheral arterial disease (PAD) and the associated risk factors for patients with COPD.

METHODS

This prospective cross-sectional study enrolled 427 COPD patients (mean age: 70.0 years) without PAD symptoms consecutively. Demographic data, lung function and cardiovascular risk factors were recorded. The ankle-brachial index (ABI) was used to detect PAD (ABI<0.90).

RESULTS

The overall prevalence of asymptomatic PAD in the COPD patients was 8% (2.5% in the younger participants (<65 years of age, n = 118) and 10% in the elderly participants (≥65 years of age, n = 309). The COPD patients with asymptomatic PAD had a significantly higher rate of hyperlipidemia (47.1% vs. 10.4%) and hypertension (79.4% vs. 45.8%) than those without asymptomatic PAD (p<0.05). There was no significant difference in lung function (forced vital capacity and forced expiratory volume in one second) between the two groups. In multivariate logistic regression, hyperlipidemia was the strongest independent factor for PAD (odds ratio (OR): 6.89, p<0.005), followed by old age (OR: 4.80), hypertension (OR: 3.39) and smoking burden (pack-years, OR: 1.02).

CONCLUSIONS

The prevalence of asymptomatic PAD among COPD patients in Taiwan is lower than in Western countries. Hyperlipidemia, old age, hypertension, and smoking burden were the associated cardiovascular risk factors. However, there was no association between lung function and PAD in the COPD patients.

Reactive oxygen species-reducing strategies improve pulmonary arterial responses to nitric oxide in piglets with chronic hypoxia-induced pulmonary hypertension

AIMS

There are no effective treatments for chronic pulmonary hypertension in infants with cardiopulmonary disorders associated with hypoxia, such as those with chronic lung disease. These patients often have poor or inconsistent pulmonary dilator responses to inhaled nitric oxide (iNO) therapy for unknown reasons. One possible explanation for poor responsiveness to iNO is reduced NO bioavailability caused by interactions between reactive oxygen species (ROS) and NO. Our major aim was to determine if strategies to reduce ROS improve dilator responses to the NO donor, S-nitroso-N-acetyl-penicillamine (SNAP), in resistance pulmonary arteries (PRAs) from a newborn piglet model of chronic pulmonary hypertension.

RESULTS

The dilation to SNAP was significantly impaired in PRAs from piglets with chronic hypoxia-induced pulmonary hypertension. ROS scavengers, including cell-permeable and impermeable agents to degrade hydrogen peroxide (H(2)O(2)), improved dilation to SNAP in PRAs from chronically hypoxic piglets. Treatment with agents to inhibit nitric oxide synthase and NADPH oxidase, potential enzymatic sources of ROS, also improved dilation to SNAP in PRAs from hypoxic piglets.

INNOVATION

Our studies are the first to utilize a newborn model of chronic pulmonary hypertension to evaluate the impact of a number of potential therapeutic strategies for ROS removal on responses to exogenous NO in the vessels most relevant to the regulation of pulmonary vascular resistance (PRA).

CONCLUSIONS

Strategies aimed at reducing ROS merit further evaluation and consideration as therapeutic approaches to improve responses to iNO in infants with chronic pulmonary hypertension.

Antioxidant effects of methylprednisolone and hydrocortisone on the impairment of endothelium dependent relaxation induced by reactive oxygen species in rabbit abdominal aorta

Background

The reperfusion following ischemia produces reactive oxygen species (ROS). We studied the influences of methylprednisolone (MPD) and hydrocortisone (CRT) on ROS effects using the endothelium of rabbit abdominal aorta.

Methods

Isolated rabbit aortic rings were suspended in an organ bath filled with Krebs-Henseleit (K-H) solution. After precontraction with norepinephrine, changes in arterial tension were recorded following the cumulative administration of acetylcholine (ACh). The percentages of ACh-induced relaxation of aortic rings before and after exposure to ROS, generated by electrolysis of K-H solution, were used as the control and experimental values, respectively. The aortic rings were pretreated with MPD or CRT at the same concentrations, and the effects of these agents were compared with the effects of ROS scavenger inhibitors: superoxide dismutase inhibitor, diethylthiocarbamate (DETCA), and the catalase inhibitor, 3-amino-1,2,4-triazole (3AT).

Results

Both MPD and CRT maintained endothelium-dependent relaxation induced by ACh in a dose-related manner in spite of ROS attack. The restored ACh-induced relaxation of MPD and CRT group was not attenuated by pretreatment of 3AT and DETCA.

Conclusions

MPD and CRT preserve the endothelium-dependent vasorelaxation against the attack of ROS, in a dose-related manner. Endothelial protection mechanisms of MPD and CRT may be not associated with hydrogen peroxide and superoxide scavenging.

Antiatherogenic and Anti-Ischemic Properties of Traditional Chinese Medicine Xinkeshu via Endothelial Protecting Function

Including herbal medicine, complementary and alternative medicine (CAM) is popular worldwide. The traditional Chinese medicine xinkeshu has been widely used to treat coronary heart disease in China. This study was designed to investigate the protective effect and probable mechanism of xinkeshu tablet to atherosclerotic myocardial ischemia rabbit. Rabbits were divided into four groups (n = 12 each) and fed with different diet for 12 weeks: Control (standard diet), Model (high-cholesterol diet), XKS (high-cholesterol diet with 184.8 mg/kg/d xinkeshu), and Atorvastatin (high-cholesterol diet with 5.0 mg/kg/d atorvastatin). Plasma lipoprotein, ECG, endothelium-dependent vessel relaxation, histomorphological study, and expressions of eNOS and VCAM-1 on coronary arteries were assessed. The findings showed that, similar to atorvastatin, xinkeshu presented significant effects on rescuing endothelium-dependent vessel relaxation, inhibiting atherosclerotic progress, preventing myocardial ischemia, and changing eNOS and VCAM-1 expression. However, xinkeshu showed no lipoprotein lowering effect in hypercholesterolemia rabbits. The results of the present study indicated that xinkeshu exerted potent antiatherogenic and anti-ischemic properties on atherosclerotic myocardial ischemia rabbit. An endothelial protecting effect may be involved in the mechanism other than antihyperlipidemic effect.