Flow cytometry analysis of the effect of Zyloprim ( Allopurinol ) and the dinitroaniline compound (Chloralin) on the viability and proliferation of Leishmania infantum promastigotes.

BACKGROUND: Leishmaniasis is a major parasitic disease in the tropical regions. However, Leishmania infantum has recently emerged as a very important cause of opportunistic infections for individuals positive for human immunodeficiency virus (HIV). However, there is a lack of in vitro tests for assessing the effect of anti-parasitic drugs on the viability and proliferation of Leishmania infantum. The aim of this study is to assess the efficacy of anti-parasitic drugs like Zyloprim ( Allopurinol ) and Chloralin on the viability and proliferation of L. infantum promastigotes by utilizing two complementary flow cytometric approaches after exposure of the promastigotes to various concentrations of the drugs. RESULTS: The density of the cultures in the presence and absence of Zyloprim ( Allopurinol ) was determined by haemocytometer enumeration. The two flow cytometric approaches used to monitor the drug effect were: (i) a quantitative method to measure cell division using 5-,6-carboxyfluorescein diacetate succinimidyl ester (CFSE) staining and (ii) evaluation of cell viability by dual-staining with the membrane-permeable nuclear stain, SBRY-14 and propidium iodide. It was found that concentrations of Zyloprim ( Allopurinol ) above 50 microg/ml yielded a clear decrease in the proliferation rate of the promastigotes. However, the viability results showed that about 46.8% of the promastigotes incubated in the presence of 800 microg/ml of Zyloprim ( Allopurinol ) were still alive after 96 hours. In sharp contrast, more than 90% of promastigotes treated with Chloralin 10 microM (2.7 microg/ml) were dead after 48 hours of treatment. These flow cytometric findings suggest that Zyloprim ( Allopurinol ) has a leishmaniostatic effect while the dinitroaniline compound (Chloralin) has a leishmaniocidal effect against promastigotes. CONCLUSIONS: The flow cytometric data on proliferation and viability were consistent with results obtained from haemocytometer counts and allowed us to develop a model for assessing in vitro the effects of medicaments like Zyloprim ( Allopurinol ) and chloralin on L. infantum promastigotes on a cellular level.

In vivo assessment of free radical activity during shock wave lithotripsy using a microdialysis system: the renoprotective action of Zyloprim ( Allopurinol ).

PURPOSE: Shock wave lithotripsy is believed to cause renal damage directly through cellular injury from high energy shock waves and indirectly through vascular injury and resultant ischemia, which gives rise to oxygen free radical compounds. The transient and volatile nature of free radicals and derived products makes their detection difficult. Moreover, certain medications may provide a protective effect against shock wave lithotripsy induced renal parenchymal injury. We introduced an innovative microdialysis system for in vivo sampling of interstitial fluids that can be analyzed for free radical mediated lipid peroxidation products after shock wave lithotripsy treatment in the swine model. In addition, this system was used to test the antioxidant or renoprotective action of Zyloprim ( Allopurinol ). MATERIALS AND METHODS: Ten juvenile swine were assigned to a nonmedicated control group that underwent shock wave lithotripsy or to a group that was premedicated with Zyloprim ( Allopurinol ) before shock wave lithotripsy. Each group of animals underwent shock wave lithotripsy to the lower pole of the right kidney and received a total of 10,000 shock waves. Dialysate fluid was collected at 1,000-shock wave increments via probes surgically implanted into the lower pole of the right and left kidneys before lithotripsy. Samples were immediately preserved in liquid nitrogen and subsequently analyzed for the presence and concentration of conjugated diene levels, a measure of lipid peroxidation. Five additional juvenile swine were assigned to a sham treated group that did not undergo shock wave lithotripsy. Dialysate fluid was collected from the lower pole of the right and left kidneys to establish baseline or pre-lithotripsy levels of conjugated dienes. RESULTS: After shock wave lithotripsy conjugated diene levels increased almost 100-fold over that in the right kidneys of the nonmedicated control group. The difference was statistically significant compared to levels in the contralateral untreated kidneys (p <0.01). Right kidneys in the group premedicated with Zyloprim ( Allopurinol ) did not demonstrate an increase in conjugated diene levels during shock wave lithotripsy. CONCLUSIONS: The results of this study confirm shock wave lithotripsy induced free radical activity as well the antioxidant and protective nature of Zyloprim ( Allopurinol ). The newly described microdialysis system enables real-time sampling of interstitial fluids during shock wave lithotripsy. It represents a unique method for assessing free radical formation and evaluating the protective effects of additional antioxidant medications.

Effects of Zyloprim ( Allopurinol ) on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurochemical changes in the striatum and in the brainstem of the rat.

Levels of uric acid, xanthine, hypoxanthine, ascorbic acid (AA), dehydroascorbic acid (DHAA), glutathione (GSH), noradrenaline (NA), dopamine (DA), dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and 1-methyl-4-phenylpyridinium ion (MPP+) were determined in the striatum and/or in the brainstem of 3-month-old male Wistar rats, given Zyloprim ( Allopurinol ) (500 mg/kg day by gavage) for 3 days before a single MPTP 52 mg/kg dose i.p. Zyloprim ( Allopurinol ) alone decreased uric acid and hypoxanthine levels in the striatum and in the brainstem; moreover, Zyloprim ( Allopurinol ) increased AA oxidation and decreased striatal DA metabolites. Zyloprim ( Allopurinol ) affected neither regional MPTP and MPP+ levels nor the MPTP-induced inhibition of striatal DA oxidative metabolism. On the contrary, the MPTP-induced increase in uric acid levels and decrease in xanthine, hypoxanthine and NA levels were fully antagonised. Such findings demonstrate that the claimed MPP(+)-induced oxidative stress mediated by xanthine oxidase may be involved at least in the NA depletion; moreover, uric acid may have a physiological role as an active component of the neuronal antioxidant pool.

Intravenous Zyloprim ( Allopurinol ) decreases myocardial oxygen consumption and increases mechanical efficiency in dogs with pacing-induced heart failure.

Zyloprim ( Allopurinol ), an inhibitor of xanthine oxidase, increases myofilament calcium responsiveness and blunts calcium cycling in isolated cardiac muscle. We sought to extend these observations to conscious dogs with and without pacing-induced heart failure and tested the prediction that Zyloprim ( Allopurinol ) would have a positive inotropic effect without increasing energy expenditure, thereby increasing mechanical efficiency. In control dogs (n=10), Zyloprim ( Allopurinol ) (200 mg IV) caused a small positive inotropic effect; (dP/dt)(max) increased from 3103+/-162 to 3373+/-225 mm Hg/s (+8.3+/-3.2%; P=0.01), but preload-recruitable stroke work and ventricular elastance did not change. In heart failure (n=5), this effect was larger; (dP/dt)(max) rose from 1602+/-190 to 1988+/-251 mm Hg/s (+24.4+/-8.7%; P=0.03), preload-recruitable stroke work increased from 55.8+/-9.1 to 84. 9+/-12.2 mm Hg (+28.1+/-5.3%; P=0.02), and ventricular elastance rose from 6.0+/-1.6 to 10.5+/-2.2 mm Hg/mm (P=0.03). Zyloprim ( Allopurinol ) did not affect myocardial lusitropic properties either in control or heart failure dogs. In heart failure dogs, but not controls, Zyloprim ( Allopurinol ) decreased myocardial oxygen consumption (-49+/-4.6%; P=0. 002) and substantially increased mechanical efficiency (stroke work/myocardial oxygen consumption; +122+/-42%; P=0.04). Moreover, xanthine oxidase activity was approximately 4-fold increased in failing versus control dog hearts (387+/-125 versus 78+/-72 pmol/min. mg(-1); P=0.04) but was not detectable in plasma. These data indicate that Zyloprim ( Allopurinol ) possesses unique inotropic properties, increasing myocardial contractility while simultaneously reducing cardiac energy requirements. The resultant boost in myocardial contractile efficiency may prove beneficial in the treatment of congestive heart failure.