The effects of amlodipine on the biochemical and histopathological changes in the rabbit ileum subjected to ischemia-reperfusion

Virulence Factors and Azole-Resistant Mechanism of Candida Tropicalis Isolated from Candidemia

BACKGROUND

Limited knowledge exists on the virulence factors of Candida tropicalis and the mechanisms of azole resistance that lead to an intensified pathogenicity and treatment failure. We aimed to evaluate the virulence factors and molecular mechanisms of azole resistance among C. tropicalis isolated from patients with candidemia.

MATERIALS AND METHODS

Several virulence factors, including extracellular enzymatic activities, cell surface hydrophobicity (CSH), and biofilm formation, were evaluated. Antifungal susceptibility pattern and expression level of ERG11, UPC2, MDR1, and CDR1 genes of eight (4 fluconazole resistance and 4 fluconazole susceptible) clinical C. tropicalis isolates were assessed. The correlation between the virulence factors and antifungal susceptibility patterns was analyzed.

RESULTS

During a 4 year study, forty-five C. tropicalis isolates were recovered from candidemia patients. The isolates expressed different frequencies of virulence determinants as follows: coagulase 4 (8.9%), phospholipase 5 (11.1%), proteinase 31 (68.9%), esterase 43 (95.6%), hemolysin 44 (97.8%), biofilm formation 45 (100%) and CSH 45(100%). All the isolates were susceptible to amphotericin B and showed the highest resistance to voriconazole. There was a significant positive correlation between micafungin minimum inhibitory concentrations (MICs) and hemolysin production (r_s = 0.316). However, we found a negative correlation between fluconazole MICs and esterase production (r_s = -0.383). We observed the high expression of ERG11 and UPC2 genes in fluconazole-resistant C. tropicalis isolates.

CONCLUSION

C. tropicalis isolated from candidemia patients extensively displayed capacities for biofilm formation, hemolysis, esterase activity, and hydrophobicity. In addition, the overexpression of ERG11 and UPC2 genes was considered one of the possible mechanisms of azole resistance.

Neuroprotective effect of roflumilast under cerebral ischaemia/reperfusion injury in juvenile rats through NLRP-mediated inflammatory response inhibition

This study aims to investigate the protective effect of roflumilast, a phosphodiesterase (PDE)-4 enzyme inhibitor, and demonstrate its possible role in the development prevention of cerebral ischemia/reperfusion injury (CI/RI) after stroke induced by carotid artery ligation in juvenile rats. The rats were randomly divided into five groups: healthy group without any treatment, healthy group administered with 1 mg/kg roflumilast, CI group not administered with roflumilast, CI group administered with 0.5 mg/kg roflumilast, and CI group administered with 1 mg/kg roflumilast. In the CI groups, reperfusion was achieved 2h after ischemia induction; in the roflumilast groups, this drug was intraperitoneally administered immediately after reperfusion and at the 12^th hour. At the end of 24h, the rats were sacrificed and their brain tissues removed for examination. The mRNA expressions obtained with real-time PCR of IL-1β, TNF-α, and NLRP3 significantly increased in the CI/RI-induced groups compared with the control group, and this increase was significantly lower in the groups administered with roflumilast compared with the CI/RI-induced groups. Moreover, ELISA revealed that both IL-1 β and IL-6 brain levels were significantly higher in the CI/RI-induced groups than in the controls. This increase was significantly lower in the groups administered with roflumilast compared with the CI/RI-induced groups. Histopathological studies revealed that the values closest to those of the healthy group were obtained from the roflumilast groups. Nissl staining revealed that the Nissl bodies manifested normal density in the healthy and roflumilast-administered healthy groups, but were rare in the CI/RI-induced groups. Roflumilast treatment increased these decreased Nissl bodies with increasing doses. Observations indicated that the Nissl body density was close to the value in the healthy group in the CI/RI-induced group administered with 1 mg/kg roflumilast. Overall, roflumilast reduced cellular damage caused by CI/RI in juvenile rats, and this effect may be mediated by NLRP3.

Protective effect of an L-type calcium channel blocker, amlodipine, on paracetamol-induced hepatotoxicity in rats

Paracetamol (P), one of the most popular and commonly used analgesic and antipyretic agents, causes hepatotoxicity in overdoses. Amlodipine (AML), an L-type calcium channel blocker, has been shown to have anti-inflammatory activity by reversing the effect of calcium in the inflammation pathogenesis. In this study, the hepatoprotective activity of AML on P-induced hepatotoxicity was evaluated. Thirty male albino Wistar rats were divided into five groups: (1) control, (2) 2 g/kg of P, (3) 2 g/kg of P + 5 mg/kg of AML, (4) 2 g/kg of P + 10 mg/kg of AML, and (5) 10 mg/kg of AML. Some liver enzymes, oxidative parameters, cytokine mRNA expressions, histopathology, and immunohistochemical studies were performed in liver and blood samples. The serum levels of alanine aminotransferase and aspartate aminotransferase and the mRNA expression of tumor necrosis factor-alpha (TNF-α) and transforming growth factor-beta in the liver tissues were significantly increased in the group treated with P. The superoxide dismutase and glutathione parameters decreased and malondialdehyde levels increased in the livers of the rats treated with P. All these parameters were increased with both doses of the AML similar to the control group. A histopathological examination of the liver showed that AML administration ameliorated the P-induced inflammatory liver damage. In immunohistochemical staining, the expression of TNF-α in the cytoplasm of the hepatocytes was increased in the P group but not in other treatment groups when compared to the control. In conclusion, AML treatment showed significant protective effects against P-induced hepatotoxicity by increasing the activity of antioxidants and reducing inflammatory cytokines.

The potential role of amlodipine on experimentally induced bacterial rhinosinusitis

Introduction

Antibiotics are frequently used for the treatment of rhinosinusitis. Concerns have been raised regarding the adverse effects of antibiotics and growing resistance. The lack of development of new antibiotic compounds has increased the necessity for exploration of non-antibiotic compounds that have antibacterial activity. Amlodipine is a non-antibiotic compound with anti-inflammatory activity.

Objective

In this study we aimed to investigate the potential role of amlodipine in the treatment of rhinosinusitis by evaluating its effects on tissue oxidative status, mucosal histology and inflammation.

Methods

Fifteen adult albino guinea pigs were inoculated with Staphylococcus aureus and treated with saline, cefazolin sodium, or amlodipine for 7 days. The control group was composed by five healthy guinea pigs. Animals were sacrificed after the treatment. Histopathological changes were identified using Hematoxylin-Eosin staining. Inflammation was assessed by Polymorphonuclear Leukocyte infiltration density. Tissue levels of antioxidants (superoxide dismutase, glutathione) and an oxidative product (malondialdehyde) were determined.

Results

In rhinosinusitis induced animals, amlodipine reduced loss of cilia, lamina propria edema and collagen deposition compared to placebo (saline) and although not superior to cefazolin, amlodipine decreased polymorphonuclear leukocyte infiltration. The superoxide dismutase activity and glutathione levels were reduced, whereas the malondialdehyde levels were increased significantly in all three-treatment groups compared to the control group. Amlodipine treated group showed significantly increased superoxide dismutase and glutathione levels and decreased malondialdehyde levels compared to all treatment groups.

Conclusion

The non-antibiotic compound amlodipine may have a role in acute rhinosinusitis treatment through tissue protective, antioxidant and anti-inflammatory mechanisms.

Effects of amlodipine on ischaemia/reperfusion injury in the rat testis

The aim of this study was to examine the effects of amlodipine (AML) in rat testicular torsion/detorsion damage. In this study, rats were divided into eight groups: (i) sham; (ii) testicular ischaemia, 2 h of ischaemia; (iii) testicular ischaemia/reperfusion (I/R), 2 h of ischaemia followed by 2 h of reperfusion; (iv) ischaemia + AML (5 mg kg(-1)) administered 30 min before ischaemia; (v) ischaemia + AML (10 mg kg(-1)) administered 30 min before ischaemia; (vi) and (vii) I/R + AML (5 mg kg(-1)) and I/R + AML (10 mg kg(-1)) administered 1.5 h after the induction of ischaemia, respectively, and at the end of a 2-h ischaemia period and a 2-h reperfusion period applied; and (viii) sham + AML (10 mg kg(-1)). Significant decreases in levels of superoxide dismutase and glutathione were observed in ischaemia and reperfusion groups when compared with healthy controls. These antioxidant levels increased in AML groups while malondialdehyde levels significantly decreased. While increases in tumour necrosis factor-alpha and transforming growth factor-beta levels were found in the torsion and detorsion groups, significant decreases in the levels of these inflammatory cytokines were observed in the treatment groups. These results demonstrate that AML significantly produced protective effects on testis tissue damage that occurs in the torsion/detorsion model via biochemical, histopathological and molecular pathways.

Propolis alleviates 2,3,7,8-Tetrachlorodibenzo-p-dioxin-induced histological changes, oxidative stress and DNA damage in rat liver

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) induces hepatic damage. Propolis exhibits antioxidant properties and several studies suggest that supplementations with antioxidants can influence hepatotoxicity. Therefore, the aim of the current study was to explore the effectiveness of propolis in alleviating the toxicity of TCDD in the liver of rats. Animals were divided into six groups, namely, TCDD (0.75 and 8 µg/kg body weight (bw)), propolis (50 mg/kg bw), TCDD (0.75 and 8 µg) plus propolis (50 mg/kg bw), and control, respectively. Rats were intraperitoneally administered with their respective doses daily for 21 days. In rats that received a high dose of TCDD, the antioxidant enzymes were significantly decreased and the serious pathological findings were established. Also, the rate of hepatocyte micronucleus (HMN) was increased after treating with TCDD. The reactions of enzymes in control and low-dose group were weak. The frequencies of HMN and liver histology were similar to both the groups. The presence of propolis with TCDD alleviated its pathological effects in hepatic tissue. Propolis also prevented the suppression of antioxidant enzymes in the livers of animals exposed to TCDD and displayed a strong protective effect against HMN. It can be concluded that propolis has beneficial influences and was able to antagonize TCDD toxicity in the liver.

Beneficial effect of astaxanthin on 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced liver injury in rats

Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) represents a potential health risk and hepatotoxicity. Astaxanthin (ASTA) exhibits antioxidant properties and can influence hepatotoxicity. Therefore, the present study was carried out for using ASTA against hepatotoxicity induced by TCDD in the liver of rats. Animals were treated intraperitoneally daily with TCDD (8 µg/kg body weight (b.w.)), ASTA (12.5 mg/kg b.w. and 25 mg/kg b.w.) and TCDD plus ASTA (12.5 and 25 mg/kg b.w.) for 21 days. TCDD significantly decreased the activities of antioxidant enzymes and resulted in serious pathological findings. Moreover, the rate of micronucleus (MN) in hepatocytes increased after treating with TCDD. The activities of enzymes, frequencies of MNs and liver histology in lower dosage group of ASTA remained unchanged compared with the control group. In rats treated with ASTA, at higher dosage alone, the MNs remained unchanged and the activities of antioxidant enzymes significantly increased. The presence of ASTA (except for lower dose) with TCDD alleviated its pathological effects in hepatic tissue. ASTA also prevented the suppression of antioxidant enzymes in the livers of animals exposed to TCDD and displayed a strong protective effect against MNs. Thus, the present findings might provide new insight into the development of therapeutic and preventive approaches of TCDD toxicity.