Effects Of Diminazene Aceturate Research Articles

Effect of Diminazene Aceturate, an ACE2 activator, on platelet CD40L signaling induced glial activation in rat model of hypertension

Hypertension causes platelet activation and adhesion in the brain resulting in glial activation and neuroinflammation. Further, activation of Angiotensin-Converting Enzyme 2/Angiotensin (1–7)/Mas Receptor (ACE2/Ang (1–7)/MasR) axis of central Renin-Angiotensin System (RAS), is known to reduce glial activation and neuroinflammation, thereby exhibiting anti-hypertensive and anti-neuroinflammatory properties. Therefore, in the present study, the role of ACE2/Ang (1–7)/MasR axis was studied on platelet-induced glial activation and neuroinflammation using Diminazene Aceturate (DIZE), an ACE2 activator, in astrocytes and microglial cells as well as in rat model of hypertension. We found that the ACE2 activator DIZE, independently of its BP-lowering properties, efficiently prevented hypertension-induced glial activation, neuroinflammation, and platelet CD40-CD40L signaling via upregulation of ACE2/Ang (1–7)/MasR axis. Further, DIZE decreased platelet deposition in the brain by reducing the expression of adhesion molecules on the brain endothelium. Activation of ACE2 also reduced hypertension-induced endothelial dysfunction by increasing eNOS bioavailability. Interestingly, platelets isolated from hypertensive rats or activated with ADP had significantly increased sCD40L levels and induced significantly more glial activation than platelets from DIZE treated group. Therefore, injection of DIZE pre-treated ADP-activated platelets into normotensive rats strongly reduced glial activation compared to ADP-treated platelets. Moreover, CD40L-induced glial activation, CD40 expression, and NFкB-NLRP3 inflammatory signaling are reversed by DIZE. Furthermore, the beneficial effects of ACE2 activation, DIZE was found to be significantly blocked by MLN4760 (ACE2 inhibitor) as well as A779 (MasR antagonist) treatments. Hence, our study demonstrated that ACE2 activation reduced the platelet CD40-CD40L induced glial activation and neuroinflammation, hence imparted neuroprotection.

Effects of diminazene aceturate on flip-flop plasma pharmacokinetics of piroxicam in dogs

ObjectivesPain, fever and inflammation associated with protozoan infections caused by Trypanosomes, Babesia, Entamoeba, Leishmania and Pneumocystis have necessitated the search for polypharmacy,that could be used for treatment of protozoan infections in dogs. MethodsRandomized cross-over controlled trial was adopted for kinetic study of piroxicam (3.5 mg/kg) and piroxicam (3.5 mg/kg) administered with diminazene aceturate (3.5 mg/kg) in Nigerian indigenous dogs. Ten dogs comprised 5 males and females, each of about 8 ± 2 months and weighed 10 ± 0.5 kg were administered piroxicam, after one month the dogs were administered piroxicam and diminazene aceturate at different thigh muscles. Single dose was administered to avoid toxicity. Blood samples were collected at 0, 0.08, 0.25, 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, 6.0, 8.0, 10, 12, 24, 48, 72 and 96 h for plasma analysis of piroxicam. ResultsFindings have shown that piroxicam was significantly (p < 0.05) slowly absorbed (5.823 ± 1.46 h−1) and eliminated (0.935 ± 0.75 h−1) as compared to piroxicam/diminazene aceturate group (7.405 ± 1.75 h−1) and (0.137 ± 0.10 h−1), respectively. Concentration maximum (Cmax = 12.659 ± 0.85 µg/ml), peak time (Tmax = 13.675 ± 9.21 h), absorption half-life (T1/2α = 0.016 ± 0.04 h), elimination rate constant (β = 0.137 ± 0.10 h−1), area under curve zero to infinity (AUC0-∞ = 778.885 ± 66.99 mg/L/h), area under moment curve (AUMC = 9820.140 ± 5.33 mg/h2/L), fraction absorbed zero to 96 h (Fab0-96h = 7.505 ± 0.00%) were significantly lower in piroxicam/diminazene aceturate (p < 0.05) as compared to Cmax(18.560 ± 2.97 µg/ml), Tmax (45.000 ± 11.49 h), T1/2α(0.250 ± 0.08 h), β (0.935 ± 0.75 h−1), AUC0-∞ (814.472 ± 86.43 mg/L/h), AUMC (36274.840 ± 9010.44 mg/h2/L), and Fab0-96h (7.848 ± 0.00%) in the piroxicam treated group, respectively. The elimination half-life was significantly lower (p < 0.05) in piroxicam (33.634 ± 9.34 h) as compared with piroxicam/diminazene aceturate (34.850 ± 11.94 h) treated group. ConclusionHence piroxicam displays flip-flop phenomenon of absorption, and could be coadministered with diminazene aceturate at single or twice dose for treatment of trypanosomosis, amoebiasis, leishmaniasis, pneumocytis and babesiosis in dogs.

Diminazene aceturate mitigates cardiomyopathy by interfering with renin-angiotensin system in a septic rat model

BackgroundThere were limited studies investigating treatments of septic cardiomyopathy (SCM), which is a common complication during sepsis. A septic rat model created by cecal ligation and puncture (CLP) was used to investigate the effects of diminazene aceturate (DIZE) in SCM.MethodsA total of 151 Wistar rats were randomly assigned into the sham, CLP, or CLP + DIZE group. Data evaluated postoperatively at 6, 12, 24, and 48 hours included: cardiac function; plasma concentrations of tumor necrosis factor-alpha (TNF-α), interleukin-6, angiotensin-(1–7) [Ang-(1–7)], angiotensin II (AngII), troponin I, and brain natriuretic peptide; expression levels of myocardial Ang-(1–7), angiotensin-converting enzyme (ACE), ACE2, and angiotensin type 1 and Mas receptors; and histological changes.ResultsWe found that the CLP + DIZE group had a lower mortality compared to the CLP group (38.5% versus 61.5%) within 48 h postoperatively, although without statistical significance. In contrast to the sham group, the CLP group had decreased cardiac functions, increased myocardial injuries, and higher TNF-α levels, which were ameliorated in the CLP + DIZE group. Furthermore, administration of DIZE could reverse the decreases of myocardial Ang-(1–7) and ACE2 expressions in the CLP group, which finally minimized the myocardial microstructure disruptions.ConclusionsIt was concluded that DIZE could mitigate the development of SCM and preserve cardiac function during sepsis possibly by interfering with the renin-angiotensin system through promoting myocardial ACE2 expression and restoring local Ang-(1–7) levels.

Abstract 028: ACE2 Activator, Diminazene, Rebalances Gut Microbial Dysbiosis and Attenuates Pulmonary Hypertension

Introduction: Our previous studies have established that increasing the levels of pulmonary Angiotensin converting enzyme2 (ACE2) either by genetic overexpression or by a small molecule activator, Diminazene aceturate (DIZE) provides protection against lung injury. In view of the mounting evidence of the involvement of the gut microbiota in inflammatory, metabolic and neurological diseases, we proposed the following hypothesis: gut dysfunction and microbial dysbiosis is associated with pulmonary hypertension (PH) and that the cardiopulmonary beneficial effect of DIZE is mediated, in part, by its influence on the gut microbial composition. Methods: PH was induced in male Sprague Dawley rats by a single injection of monocrotaline (MCT; 50mg/Kg s.c). A subset of MCT rats was treated daily with DIZE (15mg/Kg/day s.c) for 4-weeks, after which hemodynamic parameters were measured and fecal samples collected for bacterial 16S ribosomal DNA analysis. In addition, colon samples were isolated to determine tissue stiffness by ex vivo atomic force microscopy. Results: MCT administration resulted in the development of PH as evidenced by increase in right ventricular systolic pressure (RVSP - Control: 30+2; MCT: 93+10 mmHg; p&lt;0.05), which was associated with significant decreases in gut microbial richness (37%), diversity (22%), and evenness (16%). Furthermore, we observed a significant reduction in acetate- and butyrate-producing, and increases in lactate-producing bacterial population in PH animals. Elastic modulus and viscosity of the colon were increased by 61% and 86% respectively in MCT animals as compared with controls, indicating greater tissue stiffness (Elastic modulus - Control: 7.33+1.66; MCT: 11.84+3.41 kPa; Viscosity - Control: 145+19; MCT: 270+36 kPa*s; p&lt;0.05). However, chronic treatment with DIZE attenuated all these parameters (RVSP - MCT+DIZE: 52+9 mmHg; Elastic modulus - MCT+DIZE: 8.97+3.84 kPa; Viscosity - MCT+DIZE: 180+77 kPa*s; p&lt;0.05) Conclusions: These observations demonstrate for the first time that a) gut microbial dysbiosis is associated with MCT-induced PH; b) DIZE attenuates PH pathophysiology and significantly rebalances dysbiosis. They suggest that the gut microbiota could be a potential target for PH therapy.

Comparative effects of intramuscular and intravenous administration of diminazene aceturate on blood pressure and lead‐II electrocardiogram of dogs.

Diminazene aceturate (DIAC), has been used extensively in Veterinary practice as a potent antiprotozoal drug. The drug has also been reported to be a small molecule which is capable of activating angiotensin‐converting enzyme‐2 and thereby, having some cardio‐protective effect. We investigated the possible effects of DIAC when administered through the intramuscular (i/m) or intravenous (i/v) routes of dogs on cardiovascular function using blood pressure measurements and electrocardiography as clinical indices. Ten apparently normal dogs were divided into 2 groups of 5 dogs each. DIAC was administered intramuscularly at 3.5mg/kg weight to one group while the other group was treated intravenously using the same dosage. Blood pressure parameters (SBP, DBP and MAP) and lead II ECG were used to assess physiological function. Parameters were measured prior to administration and also at 10 min, 30min, 1hr, 2hrs, 3hrs. 4hrs, 6hrs, 12hrs and 24 hrs afterwards. DIAC caused a statistically significant (p&lt;0.05) reduction in SBP and MAP at 10 and 30 min post administration in both treatment groups. The i/v DIAC also caused a significant (p&lt;0.05) reduction in SDP at 10min, 6hrs and 12hrs post administration. Administration of the drugs through either routes had no significant effect on QTc (Bazett) however, there was a slight increase in QTc (fridericia) values after 30 min of i/v administration when compared with pre‐administration values. This study shows that administration of DIAC through either the i/m or i/v routes caused transient hypotension which was however restored by 1 hour post administration. Electrocardiographic assessment also did not show much remarkable aftermath.

Abstract W P196: Post-Stroke Activation of Angiotensin Converting Enzyme 2 is Neuroprotective

Background: Recent discoveries point to the angiotensin converting enzyme 2/angiotensin-(1-7)/mas (ACE2-Ang-(1-7)-Mas) axis as a potential target for neuroprotective stroke therapies. Central pre-stroke activation of this axis by infusion of diminazene aceturate (DIZE), an activator of ACE2, improves stroke outcomes in rats. This led us to hypothesize that intraperitoneal (IP) post-stroke injections of DIZE may exert similar Mas-mediated neuroprotection and thus offer additional clinically-relevant evidence to support this approach. We also assessed the direct effects of DIZE on ACE2 activity in brain tissue. Methods: Male SD rats underwent ischemic stroke by endothelin-1-induced middle cerebral artery occlusion and were randomly divided into groups (n=~12/group) that received IP injections of dH2O or DIZE (0.75, 2.5, or 7.5 mg/kg) at 4, 24, and 48 h after stroke, as well as blinded neurological assessments at 4, 24, and 72 h after stroke. Additional groups received pre- and post-stroke intracerebroventricular (ICV) infusion of sterile 0.9% saline or Mas receptor antagonist A-779 in addition to post-stroke control or drug therapy. Immediately after the 72 h tests, animals were euthanized, cerebral infarct size assessed by TTC staining, and tissue harvested for ACE2 activity assay. Data are expressed as mean ± SEM with significance inferred at p&lt;0.05. Results: Mean infarct sizes (%) were significantly decreased by post-stroke IP injections of all doses of DIZE (0.75 mg/kg: 29.9±5.0; 2.5 mg/kg: 27.9±4.2; 7.5 mg/kg: 31.36±4.1) vs. dH2O (41.9±3.8). At 24 h post-stroke, neurologic deficits (Garcia and Bederson scales) were significantly improved in DIZE-treated rats (7.5 mg/kg: 16.7±0.2 and 0.5±0.1) vs. controls (15.5±0.4 and 1.1±0.2). ICV infusion of A-779 in DIZE-treated rats abolished the improvement in infarct size observed in saline infused DIZE-treated rats (A-779: 43.8%±7.5; saline: 25.8±6.7). Addition of DIZE (4 nmol/μg protein) to brain homogenate increased ACE2 activity by more than 3-fold. Conclusions: This suggests that targeting the ACE2/Ang-(1-7)/Mas axis by post-stroke DIZE injections exerts neuroprotection in a Mas-dependent fashion.

Diminazene Aceturate Improves Autonomic Modulation in Pulmonary Hypertension

Our studies have demonstrated that diminazene aceturate (DIZE) protects rats from monocrotaline (MCT)-induced pulmonary hypertension (PH). The present study was conducted to determine if these effects of DIZE are associated with improvements in autonomic nervous system (ANS) modulation. A single dose of MCT (50mg/kg) was subcutaneously injected to induce PH. A subset of MCT rats were treated with DIZE (15mg/kg/day) for 21 days. ANS control was evaluated by spectral and symbolic analysis of heart rate variability (HRV). MCT induced a significant (p<0.001) increase in right ventricular systolic pressure (62±14mmHg) when compared to all other groups (Control: 26±6; DIZE alone: 29±5; MCT+DIZE: 31±7). MCT treatment was associated with a significant decrease in HRV versus control (s2; Control: 93±32; DIZE: 64±58; MCT+DIZE: 41±15 and MCT: 14±11) and with an increase in the cardiac sympathetic modulation, observed by 0V pattern of symbolic analysis (Control: 4±1; DIZE: 8.8±6.1; MCT+DIZE: 2.9±2.4 and MCT: 11±6.3). This observation was confirmed by the LF/HF index of spectral analysis (Control: 0.4±0.09; DIZE: 0.06±0.007; MCT+DIZE: 0.14±0.1and MCT: 1.0±0.7) which showed that DIZE was able to recover the ANS balance. Thus, our results demonstrate that MCT-induced PH is associated with a significant increase in sympathetic modulation and a decrease in HRV. Furthermore, DIZE was able to reestablish the ANS balance.

The effects of diminazene aceturate and ceftriaxone on ram sperm

Effects of diminazene aceturate and ceftriaxone disodium were evaluated on sperm quality of rams. Daily intramuscular injections of diminazene (6 mg/kg) or ceftriaxone (28.5 mg/kg) were given to each of seven Akkaraman rams assigned per drug for two days. Semen samples were collected from the rams at post-treatment 1, 4, 24, 48, 72, 144, 288 and 336 h and examined for sperm characteristics and hyaluronidase activity. Results showed that use of ceftriaxone and diminazene caused significant ( P<0.01) decreases in sperm concentration, volume and motility compared to control group within 288 h post-treatment. In addition, hyaluronidase activity increased significantly ( P<0.01) in semen of rams treated with ceftriaxone while remained unchanged in those received diminazene. In conclusion, diminazene aceturate and ceftriaxone disodium did not have any deleterious effect on hyaluronidase enzyme. However, both drugs caused impairment of sperm in rams during the 288 h.

The effects of diminazene aceturate on systemic blood pressure in clinically healthy adult dogs.

Diminazene aceturate is a commonly used antibabesial agent. It has been postulated that diminazine may induce a decrease in blood pressure and exacerbate the hypotension presented in dogs with babesiosis. This study was undertaken to assess the effect of diminazine aceturate on the blood pressure of healthy dogs. Six healthy German shepherd dogs between 18 and 24 months of age with a mean weight of 30.4 +/- 2.75 kg were used. Blood pressure was directly measured at the following time intervals: -5, 0, 5, 10, 15, 20, 25, 30, 35, 40, 50, 60, 90 and 120 minutes after treatment with diminazine aceturate (4.2 mg/kg) intramuscularly. No statistical difference (P > 0.05) was found in blood pressure between any of the time intervals. An increase in heart rate was seen 5 minutes after the administration of diminazine aceturate but no change in blood pressure was evident. This study concluded that diminazene aceturate in its current formulation with antipyrine does not alter blood pressure in healthy adult dogs.

The effect of diminazene aceturate and isometamidium chloride on cultured procyclic forms of susceptible and drug-resistant Trypanosoma congolense

Cultures of insect forms of Trypanosoma congolense stocks and clones with different susceptibilities to trypanocidal drugs in vivo were initiated from bloodstream trypomastigotes harvested from mammalian hosts and maintained axenically in vitro at 27°C. Growth inhibition of procyclic forms of susceptible and drug-resistant T. congolense occurred after incubation for 48 h with 0.1 ng isometamidium chloride/ml or 500 ng diminazene aceturate/ml. Procyclic forms were propagated in vitro in the presence of 10 or 100 ng diminazene aceturate/ml for 20 days without or with only minor loss of growth. In the presence of 0.1 or 1 ng isometamidium chloride/ml the trypanocidal effect was detectable after 6–8 days and the cultures died after 10–12 days. Concentrations of 1 or 10 ng isometamidium chloride/ml had an irreversible effect when the trypanosomes were exposed to the drug for 24 h. Both drugs used in this study thus showed antitrypanosomal activity on T. congolense procyclic forms but it was not possible to distinguish between drug-resistant and susceptible stocks or clones employing the criteria of growth inhibition or death of trypanosomes in culture.

The Effect of Diminazene Aceturate on Spienectomized Dogs with Babesia gibsoni Infection.

The effect of diminazene aceturate on splenectomized and nonspienectomized dogs with Babesia gibsoni (B. gibsoni) infection was investigated. In splenectomized dogs, the fissional and multiplicational stages of B. gibsoni were observed in peripheral blood films, and hemoglobinuria was frequently observed. These findings were different from previous reports and were not changed by administration of diminazene aceturate. It is clear that the intramuscular administration of diminazene aceturate at the dose of 3 mg/kg body weight for 3 days is not effective against B. gibsoni infection in splenectomized dogs.