Mesalazine Induces Oxidative Stress and Cytochrome c Release in Isolated Rat Heart Mitochondria: An Analysis of Cardiotoxic Effects.

Mesalazine is widely used in the management of inflammatory bowel disease. Previous studies reported that mesalazine-induced cardiotoxicity is a rare, potentially fatal complication. Mitochondria play an important role in myocardial tissue homeostasis. Deterioration in mitochondrial function will eventually lead to cardiomyocyte death and consequently cardiovascular dysfunction. The aim of the current study was to investigate the effects of mesalazine on rat heart mitochondria. Rat heart mitochondria were isolated by mechanical lysis and differential centrifugation. Parameters of mitochondrial toxicity including succinate dehydrogenase (SDH) activity, reactive oxygen species (ROS) formation, mitochondrial membrane potential (MMP) collapse, mitochondrial swelling, and cytochrome c release were evaluated. Results revealed that mesalazine induced a concentration- and time-dependent rise in mitochondrial ROS formation, inhibition of SDH, MMP collapse, mitochondrial swelling, and cytochrome c release in rat heart mitochondria. These results indicate that the cardiotoxic effects of mesalazine are most likely associated with mitochondrial dysfunction and ROS formation, which finally ends in cytochrome c release signaling and induction of apoptosis.

Toxicity of 50-nm polystyrene particles co-administered to mice with acetaminophen, 5-aminosalicylic acid or tetracycline.

We investigated whether nano-sized polystyrene particles affect drug-induced toxicity. The particles, which are widely used industrially, had diameters of 50 (NPP50), 200 (NPP200) or 1000 (NPP1000) nm. The toxic chemicals tested were acetaminophen (APAP), 5-aminosalicylic acid (5-ASA), tetracycline (TC), and sodium valproate (VPA). All treatments in the absence of the nanoparticles were non-lethal and did not result in severe toxicity. However, when mice were injected with APAP, 5-ASA or TC together with polystyrene particles, synergistic, enhanced toxicity was observed in mice injected with NPP50. These synergic effects were not observed in mice co-injected with NPP200 or NPP1000. On the other hand, co-administration of VPA and NPP50, NPP200 or NPP1000 did not elevate toxicity. The results show that NPP50 differs in hepatotoxicity depending on the drug co-administered. These findings suggest that further evaluation of the interactions between polystyrene nanoparticles and drugs is a critical prerequisite to the pharmaceutical application of nanotechnology.

Effect of 70-nm silica particles on the toxicity of acetaminophen, tetracycline, trazodone, and 5-aminosalicylic acid in mice.

Exposure to nano-sized particles is increasing because they are used in a wide variety of industrial products, cosmetics, and pharmaceuticals. Some animal studies indicate that such nanomaterials may have some toxicity, but their synergistic actions on the adverse effects of drugs are not well understood. In this study, we investigated whether 70-nm silica particles (nSP70), which are widely used in cosmetics and drug delivery, affect the toxicity of a drug for inflammatory bowel disease (5-aminosalicylic acid), an antibiotic drug (tetracycline), an antidepressant drug (trazodone), and an antipyretic drug (acetaminophen) in mice. Co-administration of nSP70 with trazodone did not increase a biochemical marker of liver injury. In contrast, co-administration increased the hepatotoxicity of the other drugs. Co-administration of nSP70 and tetracycline was lethal. These findings indicate that evaluation of synergistic adverse effects is important for the application of nano-sized materials.

Systemic mesalazine treatment prevents spontaneous skin fibrosis in PLK2-deficient mice.

Skin fibrosis is a complex biological remodeling process occurring in disease like systemic sclerosis, morphea, or eosinophilic fasciitis. Since the knowledge about the underlying pathomechanisms is still incomplete, there is currently no therapy, which prevents or reverses skin fibrosis sufficiently. The present study investigates the role of polo-like kinase 2 (PLK2) and the pro-fibrotic cytokine osteopontin (OPN) in the pathogenesis of cutaneous fibrosis and demonstrates the antifibrotic effects of systemic mesalazine treatment in vivo. Isolated primary dermal fibroblasts of PLK2 wild-type (WT) and knockout (KO) mice were characterized in vitro. Skin thickness and histoarchitecture were studied in paraffin-embedded skin sections. The effects of mesalazine treatment were examined in isolated fibroblasts and PLK2 KO mice, which were fed 100 µg/g mesalazine for 6 months via the drinking water. Compared to WT, PLK2 KO fibroblasts displayed higher spontaneous myofibroblast differentiation, reduced proliferation rates, and overexpression of the fibrotic cytokine OPN. In vitro, 72 h of treatment with 10 mmol/L mesalazine induced phenotype conversion in PLK2 KO fibroblasts and attenuated OPN expression by inhibiting ERK1/2. In vivo, dermal myofibroblast differentiation, collagen accumulation, and skin thickening were prevented by mesalazine in PLK2 KO. Plasma creatinine levels indicated good tolerability of systemic long-term mesalazine treatment. The current study reveals a spontaneous fibrotic skin phenotype and ERK1/2-dependent OPN overexpression in PLK2 KO mice. We provide experimental evidence for the antifibrotic effectiveness of systemic mesalazine treatment to prevent fibrosis of the skin, suggesting further investigation in experimental and clinical settings.

Anti-inflammatory activity of some potassium salts of N,N-disubstituted 4-aminoazobenzenesulfonic acids in rat adjuvant arthritis.

Anti-inflammatory effects of three potassium salts of N,N-disubstituted 4-aminoazobenzenesulfonic acids were investigated and compared to that of acetylsalicylic acid (ASA) in rats with adjuvant arthritis (AA). Prophylactic oral administration of all compounds in a dose of 150 mg/kg ameliorated AA symptoms in animals. The most pronounced anti-inflammatory activity at the end of the experiment showed compound 1 containing imino group: it significantly suppressed joint swelling by 48.2% in female and by 44.2% in male rats with AA. The development of polyarthritis after the treatment with this compound was the lowest in female (20%) and male (40%) rats (in control--100% of animals with polyarthritis). All derivatives, and especially compound 1, also improved the systemic parameters of disease such as blood indices and internal organs' weight, and showed no toxicity on the main organs such as liver and spleen.

Pre-clinical toxicity of a combination of berberine and 5-aminosalicylic acid in mice.

Our previous study demonstrated that a combination of alternative medicine berberine and conventional 5-aminosalicylic acid (5-ASA) showed promise to be a novel therapeutic strategy for ulcerative colitis (UC). This present study aims to sketch the pre-clinical toxicity profile of this combination (1:10 dose ratio) on mice. In acute toxicity test, the determined median lethal dose (LD50) was 278.7 mg/kg berberine plus 2787 mg/kg 5-ASA. The results from subacute toxicity test demonstrated that no toxic signs of clinical symptoms, no significant changes in hematological or biochemical parameters were detected in mice treated with 14 + 140, 28 + 280 or 56 + 560 mg/kg of berberine plus 5-ASA treatment. Histological examinations revealed that accompanied with an increase in spleen weight, frequently recorded enlargement and white pulp hyperplasia of spleen were detected in mice when exposed to three doses of combination treatments. Further in vitro assessment suggested that the spleen toxicity was originated from berberine by its inhibition in cell viability and cell proliferation of lymphocytes. The results of this study indicate that the combination of berberine and 5-ASA shows a slight toxic effect on spleen, suggesting that this combination should be used with caution for patients.

Synthesis and anti-inflammatory testing of some new compounds incorporating 5-aminosalicylic acid (5-ASA) as potential prodrugs.

This work includes the synthesis of 15 final compounds (6a-h and 7b-h) as prodrugs of 5-ASA in the form of the acid itself, esters and amides linked by an amide linkage through a spacer to the endocyclic ring N of nicotinamide. Also, 15 new intermediate compounds were prepared. The target compounds (6b, 6f, 7b, and 7e-h) revealed potent analgesic and anti-inflammatory activities in comparison to sulfasalazine and 5-ASA. In addition, ulcerogenicity, LD50, in vivo and in vitro metabolism of compound 7f were determined.

Chemoprevention of colon cancer carcinogenesis by balsalazide: inhibition of azoxymethane-induced aberrant crypt formation in the rat colon and intestinal tumor formation in the B6-Min/+ mouse.

Non-steroidal anti-inflammatory drugs (NSAIDs) including aspirin have been shown to suppress colon carcinogenesis and in some cases reduce the size of colorectal polyps. Balsalazide disodium (BSZ) is a colon-specific prodrug of the salicylate, 5-aminosalicylic acid. The aim of the present study was to test the chemopreventive activity of BSZ in two established animal models of colon tumorigenesis, azoxymethane-induced aberrant crypt formation in the rat and intestinal tumor formation in the B6-Min/+ mouse. Aberrant crypt foci (ACF) were induced in Fischer 344 rats via 2 subcutaneous injections of azoxymethane (20 mg/kg). BSZ was supplied in the drinking water for 8 weeks and ACF quantitated. B6-Min/+ mice were treated from 55 days of age for 90 days and intestinal tumors scored for number, size and location. BSZ treatment of AOM-injected rats reduced ACF formation in a dose-dependent manner by 60% with the greatest effect observed on ACF with 4 or more crypts. In B6-Min/+ mice a dose-dependent reduction of intestinal tumor number was observed which reached 80% in the distal small intestine and colon. A preliminary mechanistic study in cultured human colon cancer cells showed that both BSZ and 5-ASA inhibited colon cancer cell proliferation in vitro. However, 5-ASA but not BSZ produced changes consistent with the induction of apoptosis. BSZ produces a dose-dependent chemopreventive effect on colon carcinogenesis. A possible mechanism is consistent with the inhibition of cellular proliferation and the induction of apoptosis.

[Effects of mesalazine on liver carcinogenesis in medium-term bioassay using rats].

A two stage carcinogenesis promotion test using phenobarbital (PB) as a positive control was performed on mesalazine in rats (F344,male). Pathological and immunohistological examinations were performed to examine the cell damage and proliferation in the liver and kidneys. As the initiation treatment, groups 1,2,3 and 5 were administered 300 mg/kg diethylnitrosamine (DEN)dissolved in 0.9% physiological saline, and group 4 was administered 5 ml/kg 0.9% physiological saline once intraperitoneally. Then group 1 was orally administered a water solution (5 ml/kg) containing 0.5% CMC-Na, and groups 2,3 and 4 similar water solution but containing 150, 300 and 300 mg/kg mesalazine, respectively. Group 5 was administered 0.05% PB mixed in feed from weeks 2 to 8. Partial (2/3) hepatectomy was performed in all 5 groups at week 3 after DEN administration. NO clear differences between the groups were observed in general conditions, body weight or amount of food consumption. The number or area-size of hepatic GST-P positive altered cell foci revealed no significant differences between groups 1,2 and 3, but a significant increase in number and area-size was observed in group 5. No GST-P positive cell foci were detected in group 4. The number of altered cell foci (H.E. staining) in the DENgroups administered mesalazine was the same as that in group 1. Thus, mesalazine did not promote hepatocarcinogenesis in the present experimental system. Statistically insignificant appearances of basophilic and acidophilic changes were observed in the renal tubular epithelium and mineral deposits in the renal papillary region and cortical margin region. The PCNA labeling rate was significantly lower in group 4, corresponding with the histological finding showing no proliferation of the renal tubular epithelium. Judging from the above test results, mesalazine was likely to show neither a promotion effect on the initiation induced by DEN nor cell proliferative activity on the kidneys by administration for this experimental period.

A rare cause of diarrhea in patients with focal segmental glomerulosclerosis / Una causa poco frecuente de diarrea en pacientes con glomeruloesclerosis focal y segmentaria

No disponible

An unusual case of mesalazine intoxication: oral and rectal overloading of the rectal suppository form.

Drugs containing 5-acetylsalicylic acid (5-ASA) have been commonly used for inflammatory bowel diseases for more than half a century, but no case about overdose of suppository form of mesalazine which was taken both orally and rectally has been reported in the related literature up to now. In the present case, a 20-year-old male patient who took 14.5 g of mesalazine rectally and orally for suicide purpose is discussed. He was an ulcerative colitis patient and depressed about his illness and routine life traffic. Although it was hard for him to take the suppository form orally because of its bad taste and structure, he took it with the help of water. In the patient's colonoscopy, diffuse hyperemia and edema extending from the anal channel to the proximal rectal mucosa and a 1.5 cm diameter ulcer expanding from anal channel through the rectum were identified. No pathology was found in the upper gastrointestinal endoscopy. Routine laboratory examination was performed and no abnormality was identified in the patient's total blood account, biochemical parameters and full-urine examination. In the control rectoscopy applied to the patient 15 days later, recovery of the ulcer was observed and he was discharged to be followed in the psychiatry clinic.

Induction of oxidative DNA damage by mesalamine in the presence of copper: a potential mechanism for mesalamine anticancer activity.

Mesalamine is the first line pharmacologic intervention for patients with ulcerative colitis, and recent epidemiologic studies have demonstrated a protective association between therapeutic use of the drug and colorectal carcinoma. However, the mechanism by which this protection is afforded has yet to be elucidated. Because copper is found at higher than normal concentrations in neoplastic cell nuclei and is known to interact with phenolic compounds to generate reactive oxygen species, we investigated whether the reaction of mesalamine/copper was able to induce oxidative DNA strand breaks in φX-174 RF I plasmid DNA, and the various components of the mechanism by which the reaction occurred. Plasmid DNA strand breaks were induced by pharmacologically relevant concentrations of mesalamine in the presence of a micromolar concentration of Cu(II), and damage was inhibited by bathocuproinedisulfonic acid (BCS) and catalase. Further, we showed that the reaction of copper with mesalamine consumed molecular oxygen, which was inhibited by BCS. Electron paramagnetic resonance spectral analysis of the reaction of copper/mesalamine indicated the presence of the hydroxyl radical, which was inhibited by both BCS and catalase. This study demonstrates for the first time that through a copper-redox cycling mechanism, the copper-mediated oxidation of mesalamine is a pro-oxidant interaction that generates hydroxyl radicals which may participate in oxidative DNA damage. These results demonstrate a potential mechanism of the anticancer effects of mesalamine in patients with ulcerative colitis.

Comparative cytotoxicity of 5-aminosalicylic acid (mesalazine) and related compounds in different cell lines.

Nonsteroidal anti-inflammatory drugs can cause serious side-effects such as tubulo-interstitial nephritis. Mesalazine (5-ASA, 5-aminosalicylic acid) is used for the treatment of colitis ulcerosa, Crohn disease, and other diseases; it has been found to induce necrosis of both proximal convoluted tubules and renal papillaries. The comparative cytotoxicity of 3-, 4-, and 5-aminosalicylic acid, acetylsalicylic acid (AcSA), and the parent compound salicylic acid (SA) was investigated for the free acids and for their sodium salts. The interaction with endogenous glutathione (GSH) was also investigated. Four established cell lines were used: MDCK, LLC-PK1, NRK as renal cells, and HepG2 as hepatic cells. The free acid compounds were less toxic than their corresponding salts. Acidic 5-ASA was the most toxic of the three isomers in MDCK and LLC-PK1 cells, while NRK and HepG2 were more susceptible to acidic 3-ASA. Addition of NaOH modified the relative toxicity of 3-ASA and 5-ASA. The LLC-PK1 and HepG2 cells were more sensitive to the test chemicals as their salts than were the NRK and MDCK cells. SA and 5-ASA decreased the GSH content in renal cells and increased it in HepG2. GSH depletion with L-buthionine-(S,R)-sulfoximine enhanced the toxicity only for SA in NRK and for 5-ASA and AcSA in HepG2. No correlation between endogenous GSH and the susceptibility of MDCK and LLC-PK1 to the test compounds was observed. The results suggest that no typical nephrotoxic effect occurred. No explanation could be found for the tubulo-interstitial nephritis caused by 5-ASA therapy.