Effects of alamandine on monocrotaline-induced pulmonary hypertension in rats.

Objectives: Pulmonary arterial hypertension (PAH) is a severe and often fatal disease that is associated with oxidative stress and inflammation. Alamandine, a component of the renin-angiotensin system, known for its antioxidative, anti-inflammatory, and antifibrotic effects, has been investigated in this study to determine if it has protective effects against PAH induced by monocrotaline (MCT) and if these effects are associated with oxidative stress, inflammatory factors, and inducible nitric oxide synthase (iNOS). Materials and Methods: Rats were administered MCT (40 mg/kg) on day 0 and then received alamandine (50 mg/kg/day) via mini-osmotic pumps for 21 days starting one day later. Hemodynamic parameters, electrocardiograms, superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), inflammatory cytokines (TNF-α, IL-1ß, and NF-κB), iNOS, and MrgD receptor expression in lung tissue were evaluated at the end of the 21-day period. The MrgD receptor was quantified through immunofluorescent staining, and the histopathology of lung tissues was evaluated using hematoxylin and eosin staining. Results: The results showed that alamandine treatment significantly improved hemodynamic parameters, oxidative stress markers, inflammatory factors, and electrocardiographic data. Furthermore, treatment with alamandine decreased the levels of iNOS. Additionally, alamandine treatment decreased the expression levels of MrgD receptors in the lung tissue of MCT-induced PAH. Conclusion: In summary, this study indicates that alamandine has protective effects against monocrotaline-induced PAH, and these effects may be attributed to the inhibition of oxidative stress, inflammatory parameters, and iNOS.

Dexamethasone release from hyaluronic acid microparticle and proanthocyanidin-gelatin hydrogel in sciatic tissue regeneration.

Biodegradable microparticles are useful vehicles for the controlled release of bioactive molecules in drug delivery, tissue engineering and biopharmaceutical applications. We developed dexamethasone (Dex) encapsulation into tyramine-substituted hyaluronic acid microparticles (Dex-HA-Tyr Mp) mediated by horseradish peroxidase (HRP) crosslinking using a microfluidic device and infollowing crosslinked gelatin (Gela) with proanthocyanidin (PA) as a semi-confined bed hydrogel for the repair of sciatic tissue injury. It was found that the simultaneous use of Dex-HA-Tyr Mp and cross-linked Gela-PA hydrogel improved the physical properties of the hydrogel, including mechanical strength and degradability. The designed composite also provided a sustained release system for Dex delivery to the surrounding sites, demonstrating the applicability of the fabricated hydrogel composite for sciatic nerve tissue engineering and regeneration. The encapsulated cells were viable and showed adequate growth ability and morphogenesis during prolonged incubation in Gela-PA/HA-Tyr Mp hydrogel compared to control conditions. Interestingly, histological analysis revealed a significant increase in the number of axons in the injured sciatic nerve following treatment with Dex-HA-Tyr Mp and injectable Gela-PA hydrogel compared to other control groups. In conclusion, the results demonstrated that fabricated Dex-loaded MPs and injectable hydrogel from biomimetic components are suitable systems for sustained delivery of Dex with adequate biocompatibility and the approach may have potential therapeutic applications in peripheral nerve regeneration.

Enhancement of bactericidal effects of bacteriophage and gentamicin combination regimen against Staphylococcus aureus and Pseudomonas aeruginosa strains in a mice diabetic wound model.

Diabetic patients are more susceptible to developing wound infections resulting in poor and delayed wound healing. Bacteriophages, the viruses that target-specific bacteria, can be used as an alternative to antibiotics to eliminate drug-resistant bacterial infections. Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) are among the most frequently identified pathogens in diabetic foot ulcers (DFUs). The aim of this study was assessment of bacteriophage and gentamicin combination effects on bacterial isolates from DFU infections. Specific bacteriophages were collected from sewage and animal feces samples and the phages were enriched using S. aureus and P. aeruginosa cultures. The lytic potential of phage isolates was assessed by the clarity of plaques. We isolated and characterized four lytic phages: Stp2, Psp1, Stp1, and Psp2. The phage cocktail was optimized and investigated in vitro. We also assessed the effects of topical bacteriophage cocktail gel on animal models of DFU. Results revealed that the phage cocktail significantly reduced the mortality rate in diabetic infected mice. We determined that treatment with bacteriophage cocktail effectively decreased bacterial colony counts and improved wound healing in S. aureus and P. aeruginosa infections, especially when administrated concomitantly with gentamicin. The application of complementary therapy using a phage cocktail and gentamicin, could offer an attractive approach for the treatment of wound diabetic bacterial infections.

Subacute toxicity of chlorpyrifos on histopathological damages, antioxidant activity, and pro-inflammatory cytokines in the rat model.

Chlorpyrifos (CPF) is an extensively used organophosphorus pesticide for agricultural, industrial, and domestic purposes. Previous studies have reported the adverse effects of CPF, such as intoxication incidents, endocrine disruption, cardiovascular diseases, as well as histopathological and oxidative damage. The aims of the present study were to elucidate short time subacute toxicity of CPF in male rats. Sprague-Dawley male rats (n = 32) were divided into four groups (n = 8) and received CPF as 3.25 mg/kg body weight (b.w) (Group A), 6.75 mg/kg b.w (Group B), 13.5 mg/kg b.w (Group C), and corn oil (control or Group D) daily via gavage for 15 days. The rats were sacrificed and oxidative damages, pro-inflammatory cytokines (TNF-α, IL-1ß), and histopathological changes were determined in the lung, liver, kidney, heart, and testis tissues as well as plasma. According to our result, administration of CPF caused a significant increase in malondialdehid level and catalase activity while a significant decrease in superoxide dismutase activity in all tissues. In addition, a significant decrease in TNF-α observed in all tissues and plasma duo to the CPF. Histopathological evaluation of CPF-treated samples revealed a dose-dependent tissue toxicity in the liver, heart, lung, and kidney with less sensitivity of testicular and kidney tissues. These results suggest the potential of CPF in inducing oxidative stress at low doses and short duration time with similar trends in different tissues. As well as, due to the effects of CPF on some pro-inflammatory mediators, more comprehensive studies are recommended.

Alamandine: Potential Protective Effects in SARS-CoV-2 Patients.

Coronavirus disease 2019 (COVID-19) can occur due to contracting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). COVID-19 has no confined treatment and, consequently, has high hospitalization and mortality rates. Moreover, people who contract COVID-19 present systemic inflammatory spillover. It is now known that COVID-19 pathogenesis is linked to the renin-angiotensin system (RAS). COVID-19 invades host cells via the angiotensin-converting enzyme 2 (ACE2) receptor-as such, an individual's susceptibility to COVID-19 increases alongside the upregulation of this receptor. COVID-19 has also been associated with interstitial pulmonary fibrosis, which leads to acute respiratory distress, cardiomyopathy, and shock. These outcomes are thought to result from imbalances in angiotensin (Ang) II and Ang-(1-7)/alamandine activity. ACE2, Ang-(1-7), and alamandine have potent anti-inflammatory properties, and some SARS-CoV-2 patients exhibit high levels of ACE2 and Ang-(1-7). This phenomenon could indicate a failing physiological response to prevent or reduce the severity of inflammation-mediated pulmonary injuries. Alamandine, which is another protective component of the RAS, has several health benefits owing to its antithrombogenic, anti-inflammatory, and antifibrotic characteristics. Alamandine alleviates pulmonary fibrosis via the Mas-related G protein-coupled receptor D (MrgD). Thus, a better understanding of this pathway could uncover novel pharmacological strategies for altering proinflammatory environments within the body. Following such strategies could inhibit fibrosis after SARS-CoV-2 infection and, consequently, prevent COVID-19.

Possible Risk of Thrombotic Events following Oxford-AstraZeneca COVID-19 Vaccination in Women Receiving Estrogen.

People who receive the ChAdOx1 nCoV-19 vaccine, particularly perimenopausal women who are on birth control or postmenopausal women who take estrogen supplements, may experience thrombosis and thrombocytopenia. Estrogen and the ChAdOx1 nCoV-19 vaccine both have the potential to cause thrombus in different ways. Some postmenopausal women who are also taking estrogens may develop thrombosis and thrombocytopenia after receiving the ChAdOx1 nCoV-19 vaccine. Therefore, women are encouraged to stop taking drugs containing estrogen before receiving this vaccine. Furthermore, consuming fish oil can help reduce the risk of developing blood clots among women who are in the luteal phase and, thus, have high estrogen levels. In addition, ChAdOx1 nCoV-19's side effects in young women could be mitigated by administering it during the follicular phase.

Protective effect of alamandine on doxorubicin­induced nephrotoxicity in rats.

BACKGROUND: This study aimed to evaluate the protective effects of alamandine, a new member of the angiotensin family, against doxorubicin (DOX)-induced nephrotoxicity in rats. METHODS: Rats were intraperitoneally injected with DOX (3.750 mg/kg/week) to reach a total cumulative dose of 15 mg/kg by day 35. Alamandine (50 µg/kg/day) was administered to the rats via mini-osmotic pumps for 42 days. At the end of the experiment, rats were placed in the metabolic cages for 24 h so that their water intake and urine output could be measured. After scarification, the rats' serum and kidney tissues were collected, and biochemical, histopathological, and immunohistochemical studies were carried out. RESULTS: DOX administration yielded increases in pro-inflammatory cytokines, including interleukin (IL)-1ß and IL-6, pro-fibrotic proteins transforming growth factor-ß (TGF-ß), pro-inflammatory transcription factor nuclear kappa B (NF-κB), kidney malondialdehyde (MDA), creatinine clearance, blood urea nitrogen (BUN), and water intake. On the other hand, the DOX-treated group exhibited decreased renal superoxide dismutase (SOD), renal glutathione peroxidase (GPx) activity, and urinary output. Alamandine co-therapy decreased these effects, as confirmed by histopathology and immunohistochemical analysis. CONCLUSIONS: The results suggest that alamandine can prevent nephrotoxicity induced by DOX in rats.

Angiotensin (1-7) and Apelin co-therapy: New strategy for heart failure treatment of rats.

OBJECTIVE: Isoproterenol (ISO)-induced heart failure is a standardized model for the study of beneficial effects of various drugs. Both apelin and angiotensin 1-7 have a cardiac protective effect. We assumed that co-therapy with apelin and angiotensin 1-7 (Ang (1-7)) may have synergistic cardioprotective effects against isoproterenol-induced heart failure. Methods The animals were randomly assigned to one of eight groups of seven animals in each group as follows: (1) control I (saline; IP injection) (1) control II (saline; via mini-osmotic pump) (3) ISO (5 mg/ kg; IP), (4) Apelin (20µg/ kg; IP), (5) Ang (1-7) (30 µg/kg/day; via mini-osmotic pump), (6) Apelin+ISO, (7) Ang (1-7)+ISO, (8) Apelin+Ang (1-7)+ISO. Rat myocardial injury was induced by intraperitoneal injection of 5mg/kg of ISO for ten days. Apelin and Ang (1-7) were administered 30 minutes before ISO injection. RESULTS: A decrease in systolic blood pressure (SBP; p<0.001), diastolic blood pressure (DBP; p<0.05), left ventricular systolic pressure (LVSP; p<0.001), left ventricular contractility (dP / dt max; p<0.001), relaxation (dP / dt min; p<0.001) and an increase in left ventricular end-diastolic pressure (LVEDP; p<0.001) were observed in ISO-treated rats. Plasma LDH and myocardial and plasma MDA were higher in the ISO heart than in controls (P<0.001). Histopathological examination of cardiac tissue showed myocardial fibrosis and leukocyte infiltration in ISO-treated rats as compared to control. Co- therapy with apelin and Ang (1-7) was more effective than either agent used alone in restoring these parameters to that of control rats. CONCLUSION: The results of this study showed that the combination of apelin and ang (1-7) had a more cardioprotective effect than either used alone against ISO-induced heart failure, and co-therapy may be a useful treatment option for myocardial injuries and heart failure.

Differences in Cardiovascular Responses to Alamandine in Two-Kidney, One Clip Hypertensive and Normotensive Rats.

BACKGROUND: Alamandine is a newly discovered component of the renin-angiotensin system, which regulates blood pressure. In this study, the effect of alamandine on cardiovascular parameters in two-kidney, one clip (2K1C) hypertensive rats and normotensive rats, and the possible roles of the angiotensin II type 1 receptor (AT1R) and the PD123319-sensitive receptors in mediating this effect was investigated.Methods and Results:The cardiovascular parameters were monitored for 10 min before the infusion of the drugs or saline, and for 30 min afterward. In the 2K1C hypertensive rats, alamandine caused brief increases in mean arterial pressure (MAP), left-ventricular systolic pressure (LVSP) and maximum rate of pressure change in the left ventricle (dP/dt(max)). This was followed by decreases in these parameters, which extended throughout the remainder of the infusion period. Losartan, an AT1R blocker, abolished alamandine's initial pressor effect and PD123319, which can block AT2R and Mas-related G protein-coupled receptor D (MrgD) receptors, partially decreased the late depressor effect. Left ventricular end-diastolic pressure (LVEDP) decreased during alamandine infusion; this effect was reduced by PD123319. In the normotensive rats, alamandine increased MAP, LVSP, dP/dt (max), and it decreased LVEDP during the infusion period. These effects of alamandine were reduced by losartan. CONCLUSIONS: The results of this investigation suggest that, under normal conditions, alamandine acts via AT1R, but in pathological conditions such as hypertension, its effect on PD123319-sensitive receptors masks its effect on AT1R.

Investigation of changes in apelin receptor mRNA and protein expression in the myocardium and aorta of rats with two-kidney, one-clip (2K1C) Goldblatt hypertension

Experimental and clinical evidences suggest that apelin and its receptor APJ are involved in the pathogenesis of cardiovascular complications. However, the role of apelin/APJ in hypertension is not sufficiently understood. Because chronic kidney diseases lead to hypertension and cardiac failure, we investigated the changes in apelin receptor gene expression in the myocardium and aorta of rat models of kidney disease hypertension. Two-kidney, one-clip (2K1C) hypertension was produced by placing a clip around the renal artery. Four and 16 weeks later, blood pressure, left ventricular end-diastolic pressure (LVEDP), serum apelin, and angiotensin II were measured. The messenger RNA (mRNA) and protein of APJ were determined by reverse transcription polymerase chain reaction (RT-PCR) and Western blotting. Chronic hypertensive rats had approximately 10 times higher LVEDP (P < 0.001). 2K1C decreased serum apelin from 220 ± 11 to 170 ± 10 pg/mL in 16 weeks (P < 0.05). The mRNA expression of APJ significantly decreased in the heart and aorta at 4 weeks. At 16 weeks, the reduction was not significant in the heart but was significant in the aorta. At 4 weeks, the expression of the APJ protein significantly decreased in the heart but not in the aorta. At 16 weeks, APJ protein was significantly decreased only in the aorta. Reduction of serum apelin and downregulation of apelin receptors in both the heart and aorta may play a role in the pathophysiology of hypertension and cardiac failure in 2K1C hypertensive rats

Investigation of changes in apelin receptor mRNA and protein expression in the myocardium and aorta of rats with two-kidney, one-clip (2K1C) Goldblatt hypertension.

Experimental and clinical evidences suggest that apelin and its receptor APJ are involved in the pathogenesis of cardiovascular complications. However, the role of apelin/APJ in hypertension is not sufficiently understood. Because chronic kidney diseases lead to hypertension and cardiac failure, we investigated the changes in apelin receptor gene expression in the myocardium and aorta of rat models of kidney disease hypertension. Two-kidney, one-clip (2K1C) hypertension was produced by placing a clip around the renal artery. Four and 16 weeks later, blood pressure, left ventricular end-diastolic pressure (LVEDP), serum apelin, and angiotensin II were measured. The messenger RNA (mRNA) and protein of APJ were determined by reverse transcription polymerase chain reaction (RT-PCR) and Western blotting. Chronic hypertensive rats had approximately 10 times higher LVEDP (P < 0.001). 2K1C decreased serum apelin from 220 ± 11 to 170 ± 10 pg/mL in 16 weeks (P < 0.05). The mRNA expression of APJ significantly decreased in the heart and aorta at 4 weeks. At 16 weeks, the reduction was not significant in the heart but was significant in the aorta. At 4 weeks, the expression of the APJ protein significantly decreased in the heart but not in the aorta. At 16 weeks, APJ protein was significantly decreased only in the aorta. Reduction of serum apelin and downregulation of apelin receptors in both the heart and aorta may play a role in the pathophysiology of hypertension and cardiac failure in 2K1C hypertensive rats.

Apelin receptor expression in ischemic and non- ischemic kidneys and cardiovascular responses to apelin in chronic two-kidney-one-clip hypertension in rats.

BACKGROUND: Chronic kidney diseases lead to severe cardiovascular consequences such as hypertension and cardiac failure. Apelin, along with its receptor APJ have been shown to involve in cardiovascular functions including blood pressure (BP) lowering effect and also a positive inotropic effect on failing hearts. Therefore we investigated the effect of apelin on BP and cardiac contractility in chronic two-kidney-one-clip (2K1C) hypertension, a kidney disease hypertension model. The changes in the level of apelin and some other hemodynamically effective hormones in serum and apelin receptor gene expression in nonischemic and ischemic kidneys were also assessed. METHODS: 2K1C was produced by placing a Plexiglas clip around the left renal artery. 16 weeks later, BP and cardiac indices of contractility were measured by power lab system. The mRNA and protein level of APJ were determined by RT-PCR and Western blot methods respectively. RESULTS: 2K1C increased BP from 115/75 mmHg in sham to 180/120 mmHg in test group. Hypertensive rats had about ten times higher basal left ventricular end-diastolic pressure (LVEDP) (P<0.001) and higher basal LV systolic pressure (LVSP) (P<0.01). Apelin-13 (20 µg/kg, iv) significantly decreased LVEDP and LVSP (P<0.001). Furthermore, apelin in 20 µg/kg dose significantly decreased systolic (SBP) and diastolic (DBP) blood pressures in hypertensive rats. This reduction was persistent and prominent in 40 µg/kg dose. 20 µg/kg apelin increased +LVdp/dt max and -LV dp/dt max. However in the dose of 40 µg/kg SBP, DBP, +LVdp/dt max and -LV dp/dt max greatly decreased. All of these effects were completely blocked by apelin antagonist F13A. 2K1C decreased serum apelin (P<0.05), did not change ang II and arginine-vasopressin levels, and slightly increased serum aldosterone. Apelin receptor mRNA and protein expression significantly decreased in both ischemic and non-ischemic kidneys. CONCLUSION: Overall, chronic 2K1C rats showed hypertension and signs of cardiac failure. Apelin in medium doses induced antihypertensive and positive myocardial inotropic effects. Reduction of serum apelin and down regulation of apelin receptors in kidneys of hypertensive rats may play a role in pathophysiology of cardiovascular complications.

The effects of cyclooxygenase inhibitors on the brain inflammatory response following traumatic brain injury in rats.

OBJECTIVES: Cytokines such as IL-1ß are involved in inflammatory responses. This study evaluated the role of two different kinds of drugs (ibuprofen and celecoxib) on brain IL-10 and IL-1ß after traumatic brain injury (TBI) in male rats. MATERIALS AND METHODS: Rats were assigned into 6 groups: intact, sham, TBI, and treated rats with vehicle, celecoxib or iboprophen. Cytokine concentrations were quantified by ELISA kits. RESULTS: Groups showed no significant difference in brain IL-10 either after TBI induction or after treatment with ibuprofen or celecoxib. Serum IL-10 in vehicle or ibuprofen treated animals was lower than in sham groups (P< 0.01). Brain IL-1ß decreased after treatment by ibuprofen or celecoxib (P< 0.001). There was no statistical difference in serum IL-1ß in TBI and intact. Serum IL-1ß significantly decreased in rats that received celecoxib compared to TBI group (P< 0.01). CONCLUSION: Based on our study IL-1ß can decrease through both cyclooxygenase 1 (COX-1) and COX-2 pathway but serum IL-1ß can decrease only by COX-2 pathway.

Cardiovascular responses to apelin in two-kidney-one-clip hypertensive rats and its receptor expression in ischemic and non-ischemic kidneys.

BACKGROUND: Apelin and its receptor APJ have been shown to have beneficial effects on cardiovascular function. Apelin was shown to elicit hypotensive effects and also a positive inotropic effect on failing hearts. In this study, we investigated the effect of apelin on blood pressure and cardiac contractility in a two-kidney-one-clip (2K1C) hypertension model. We also assessed the changes in the level of apelin and some other hemodynamically effective hormones in serum and apelin receptor gene expression in nonischemic and ischemic kidneys. METHODS: 2K1C was produced by placing a Plexiglas clip around the left renal artery. Four weeks later, blood pressure (BP) and cardiac indices of contractility were measured by power lab system. The sample venous blood was drawn from the jugular vein for biochemical variable measurements. The mRNA and protein level of APJ were determined in the kidneys by RT-PCR and Western blot methods respectively. RESULTS: The findings showed that, 2K1C increased BP from 116/75 in sham group to 200/140 mmHg in test group. Furthermore, intravenous administration of apelin-13 to hypertensive rats significantly decreased systolic (SBP) and diastolic (DBP) blood pressures in dose of 20 µg/kg with maximal responses within 2 min of injection. This reduction was long lasting and prominent in dose of 40 µg/kg. Apelin at dose of 20 µg/kg increased +LVdp/dt max and -LVdp/dt max. However at dose of 40 µg/kg SBP, DBP, +LVdp/dt max and -LVdp/dt max strongly decreased. All of the observed effects were completely blocked by apelin antagonist F13A. 2K1C did not change serum apelin, aldosterone and arginine-vasopressin levels but significantly increased angiotensin II level. 2K1C hypertension decreased apelin receptor mRNA and protein expression in contra lateral (nonischemic) kidney, but these were not affected in clipped kidney. CONCLUSION: Apelin induces hypotensive and positive inotropic effects in medium doses. However, in higher doses it elicits hypotensive and negative inotropic effects in 2K1C rats. Down regulation of apelin receptor in nonischemic kidney of hypertensive rats may play a role in pathophysiology of renovascular hypertension. Apelin together with renin-angiotensin antagonism may play a useful role in treatment of this type of hypertension.

Role of glutamatergic receptors located in the nucleus raphe magnus on antinociceptive effect of morphine microinjected into the nucleus cuneiformis of rat.

Neurons in the nucleus cuneiformis (CnF), located just ventrolateral to the periaqueductal gray, project to medullary nucleus raphe magnus (NRM), which is a key medullary relay for descending pain modulation and is critically involved in opioid-induced analgesia. Previous studies have shown that antinociceptive response of CnF-microinjected morphine can be modulated by the specific subtypes of glutamatergic receptors within the CnF. In this study, we evaluated the role of NMDA and kainate/AMPA receptors that are widely distributed within the NRM on morphine-induced antinociception elicited from the CnF. Hundred and five male Wistar rats weighing 250-300 g were used. Morphine (10, 20 and 40 microg) and NMDA receptor antagonist, MK-801 (10 microg) or kainate/AMPA receptor antagonist, DNQX (0.5 microg) in 0.5 microl saline were stereotaxically microinjected into the CnF and NRM, respectively. The latency of tail-flick response was measured at set intervals (2, 7, 12, 17, 22, 27 min after microinjection) by using an automated tail-flick analgesiometer. The results showed that morphine microinjection into the CnF dose-dependently causes increase in tail-flick latency (TFL). MK-801 microinjected into the NRM, just 1 min before morphine injection into the CnF, significantly attenuated antinociceptive effects of morphine. On the other hand, DNQX microinjected into the NRM, significantly increased TFL after local application of morphine into the CnF. We suggest that morphine related antinociceptive effect elicited from the CnF is mediated, in part, by NMDA receptor at the level of the NRM whereas kainite/AMPA receptor has a net inhibitory influence at the same pathway.