The effect of the thioether-bridged, stabilized angiotensin-(1-7) analogue cyclic Ang-(1-7) on cardiac remodeling and endothelial function in rats with myocardial infarction

Modulation of renin-angiotensin system (RAS) by angiotensin-(17) (Ang-(17)) is an attractive approach to combat the detrimental consequences of myocardial infarction (MI). However Ang-(17) has limited clinical potential due to its unfavorable pharmacokinetic profile. We investigated effects of a stabilized, thioether-bridged analogue of Ang-(17) called cyclic Ang-(17) in rat model of myocardial infarction. Rats underwent coronary ligation or sham surgery. Two weeks thereafter infusion with 0.24 or 2.4 μg/kg/h cAng-(17) or saline was started for 8 weeks. Thereafter, cardiac morphometric and hemodynamic variables as wells as aortic endothelial function were measured. The average infarct size was 13.8 and was not changed by cAng-(17) treatment. MI increased heart weight and myocyte size, which was restored by cAng-(17) to sham levels. In addition, cAng-(17) lowered left ventricular end-diastolic pressure and improved endothelial function. The results suggest that cAng-(17) is a promising new agent in treatment of myocardial infarction and warrant further research.</p

The effect of the thioether-bridged, stabilized angiotensin-(1-7) analogue cyclic Ang-(1-7) on cardiac remodeling and endothelial function in rats with myocardial infarction

Modulation of renin-angiotensin system (RAS) by angiotensin-(17) (Ang-(17)) is an attractive approach to combat the detrimental consequences of myocardial infarction (MI). However Ang-(17) has limited clinical potential due to its unfavorable pharmacokinetic profile. We investigated effects of a stabilized, thioether-bridged analogue of Ang-(17) called cyclic Ang-(17) in rat model of myocardial infarction. Rats underwent coronary ligation or sham surgery. Two weeks thereafter infusion with 0.24 or 2.4 μg/kg/h cAng-(17) or saline was started for 8 weeks. Thereafter, cardiac morphometric and hemodynamic variables as wells as aortic endothelial function were measured. The average infarct size was 13.8 and was not changed by cAng-(17) treatment. MI increased heart weight and myocyte size, which was restored by cAng-(17) to sham levels. In addition, cAng-(17) lowered left ventricular end-diastolic pressure and improved endothelial function. The results suggest that cAng-(17) is a promising new agent in treatment of myocardial infarction and warrant further research.</p

The Effect of the Thioether-Bridged, Stabilized Angiotensin-(1–7) Analogue Cyclic Ang-(1–7) on Cardiac Remodeling and Endothelial Function in Rats with Myocardial Infarction

Modulation of renin-angiotensin system (RAS) by angiotensin-(1–7) (Ang-(1–7)) is an attractive approach to combat the detrimental consequences of myocardial infarction (MI). However Ang-(1–7) has limited clinical potential due to its unfavorable pharmacokinetic profile. We investigated effects of a stabilized, thioether-bridged analogue of Ang-(1–7) called cyclic Ang-(1–7) in rat model of myocardial infarction. Rats underwent coronary ligation or sham surgery. Two weeks thereafter infusion with 0.24 or 2.4 μg/kg/h cAng-(1–7) or saline was started for 8 weeks. Thereafter, cardiac morphometric and hemodynamic variables as wells as aortic endothelial function were measured. The average infarct size was 13.8% and was not changed by cAng-(1–7) treatment. MI increased heart weight and myocyte size, which was restored by cAng-(1–7) to sham levels. In addition, cAng-(1–7) lowered left ventricular end-diastolic pressure and improved endothelial function. The results suggest that cAng-(1–7) is a promising new agent in treatment of myocardial infarction and warrant further research

Evaluation of acrylamide exposure in pregnant Wistar rats as a risk of developing renal disease in their litters

This study was designed at evaluating the acrylamide (ACR) exposure in pregnant Wistar rats as a risk of developing renal disease in their litters. Four groups of pregnant female rats were used. Group 1 control animals were given 2 ml/kg/day of distilled water. Groups 2, 3, and 4 animals were given oral gavage doses of 2, 5, and 10 mg/kg/day of ACR respectively immediately pregnancy was confirmed. Mother rats were sacrificed 10 weeks after delivery and litters were sacrificed at 13 weeks. Proteinuria was observed in ACR-treated mother rats and their litters. Serum electrolytes, urea, and creatinine values observed in the treated group were deranged for both the mothers and litters respectively. Disruption of nephrogenesis was observed in the litters of ACR-treated mother compared to the control. The results of the effect of ACR on lipid profile indicated a significant elevation in the LDL, cholesterol, and triglyceride compared to the control. There was significant reduction in the SOD, catalase, GSH, and significant elevation in the C-reactive protein and malondialdehyde. Conclusively, exposure to acrylamide during pregnancy is a risk factor for the development of renal disease in the mother rats and their litters

Use of hydrophobins in formulation of water insoluble drugs for oral administration

The poor water solubility of many drugs requires a specific formulation to achieve a sufficient bioavailability after oral administration. Suspensions of small drug particles can be used to improve the bioavailability. We here show that the fungal hydrophobin SC3 can be used to make suspensions of water insoluble drugs. Bioavailability of two of these drugs, nifedipine and cyclosporine A (CyA), was tested when administered as a SC3-based suspension. SC3 (in a 1:2 (w/w) drug:SC3 ratio) or 100% PEG400 increased the bioavailability of nifedipine to a similar degree (6±2- and 4±3-fold, respectively) compared to nifedipine powder without additives. Moreover, SC3 (in a 7:1 (w/w) drug:hydrophobin ratio) was as effective as a 20-fold diluted Neoral® formulation by increasing bioavailability of CyA 2.3±0.3-fold compared to CyA in water. Interestingly, using SC3 in the CyA formulation resulted in a slower uptake (p < 0.001 in Tmax) of the drug, with a lower peak concentration (Cmax 1.8 mg ml−1) at a later time point (Tmax 9±2 h) compared to Neoral® (Cmax 2.2 mg ml−1; Tmax 3.2±0.2). Consequently, SC3 will result in a more constant, longer lasting drug level in the body. Taken together, hydrophobins are attractive candidates to formulate hydrophobic drugs.

The antitumor activity of hydrophobin SC3, a fungal protein

The use of mushroom extracts has been common practice in traditional medicine for centuries, including the treatment of cancer. Proteins called hydrophobins are very abundant in mushrooms. Here, it was examined whether they have antitumor activity. Hydrophobin SC3 of Schizophyllum commune was injected daily intraperitoneally starting 1 day after tumor induction in two tumor mouse models (sarcoma and melanoma). SC3 reduced the size and weight of the melanoma significantly, but the sarcoma seemed not affected. However, microscopic analysis of the tumors 12 days after induction revealed a strong antitumor effect of SC3 on both tumors. The mitotic activity of the tumor decreased 1.6- (melanoma) to 2.3-fold (sarcoma), while the vital mass decreased 2.3- (melanoma) to 4.3-fold (sarcoma) compared to the control. Treatment did not cause any signs of toxicity. Behavior, animal growth, and weight of organs were similar to animals injected with vehicle, and no histological abnormalities were found in the organs. In vitro cell culture studies revealed no direct cytotoxic effect of SC3 towards sarcoma cells, while cytotoxic activity was observed towards melanoma cells at a high SC3 concentration. Daily treatment with SC3 did not result in detectable levels of anti-SC3 antibodies in the plasma. Instead, a cellular immune response was observed. Incubation of spleen cells with SC3 resulted in a 1.5- to 2.5-fold increase in interleukin-10 and TNF-α mRNA levels. In conclusion, the nontoxic fungal hydrophobin SC3 showed tumor-suppressive activity possibly via immunomodulation and may be of benefit as adjuvant in combination with chemotherapy and radiation