Mechanism Underlying Triple VEGFR Inhibitor Tivozanib-Induced Hypertension in Mice Model.

Tivozanib is a triple vascular endothelial growth factor receptor inhibitor, recently approved for the treatment of refractory advanced renal cell carcinoma. Clinical studies showed that around 46% of patients who received tivozanib suffer from hypertension in all grades. Thus, the present study was conducted to identify the role of angiotensin-II (AngII) in the mechanism underlying tivozanib-induced vascular toxicity and hypertension. C57BL/6 male mice received tivozanib (1 mg/kg) with or without losartan (10 or 30 mg/kg) for 3 weeks. Blood pressure was recorded every 3 days, and proteinuria was measured every week. On day 21, all mice were euthanized, and samples were harvested for further analysis. Tivozanib elevated blood pressure until systolic blood pressure reached 163 ± 6.6 mmHg on day 21 of treatment with low urination and high proteinuria. AngII and its receptors, endothelin-1, and oxidative stress markers were significantly increased. While nitric oxide (NO) levels were reduced in plasma and aortic tissues. AngII type 1 receptor blockade by losartan prevented these consequences caused by tivozanib and kept blood pressure within normal range. The results showed that AngII and ET-1 might be potential targets in the clinical studies and management of hypertension induced by tivozanib.

Dapagliflozin Mitigates Hypotension in Lipopolysaccharide-Induced Acute Inflammation Independent of Glycemia Level.

Sodium-glucose cotransporter-2 (SGLT2) inhibitors have been suggested to have anti-inflammatory properties in diabetes. The goal of this study was to evaluate the role of the SGLT2 inhibitor dapagliflozin (DAPA) in the attenuation of lipopolysaccharide (LPS)-induced hypotension. Male Wistar albino rats were divided into normal and diabetic groups and received DAPA (1 mg/kg/day) for two weeks followed by a single dose of 10 mg/kg LPS. Blood pressure was recorded throughout the study and the circulatory levels of cytokines were assessed using a multiplex array, while the aortas were harvested for analysis. DAPA attenuated the vasodilation and hypotension caused by LPS. Mean arterial pressure (MAP) was preserved in the normal and diabetic DAPA-treated septic groups (MAP = 83.17 ± 5.27, 98.43 ± 5.57 mmHg) compared to the vehicle-treated septic groups (MAP = 65.60 ± 3.31, 68.21 ± 5.88 mmHg). Most of the cytokines induced by LPS were decreased in the DAPA-treated septic groups. In the aorta, the inducible nitric oxide synthase-derived nitric oxide had lower expression in the DAPA-treated rats. In contrast, the expression of α-smooth muscle actin, a marker of the vessel's contractile state, was higher in the DAPA-treated rats in comparison with non-treated septic rats. These findings revealed that the protective role of DAPA against LPS-induced hypotension is likely to be glucose-lowering independent, as was observed in the non-diabetic septic group. Taken together, the results show that DAPA has a potential effect in the prevention of the hemodynamic disturbances of sepsis regardless of glycemia levels.

Butterbur (Petasites hybridus) Extract Ameliorates Hepatic Damage Induced by Ovalbumin in Mice.

The liver is the most vital organ that could be influenced by inducers of hypersensitivity such as ovalbumin. The current study was carried out to explore the effects of butterbur (Petasites hybridus) extract on the ovalbumin-induced liver hypersensitivity in Swiss albino male mice. Animals were divided into 4 groups, 1st group served as a control group, 2nd group treated with daily oral administration of 75 mg/kg of butterbur extract, 3rd group received single oral dose 100 mg/kg of ovalbumin to induce hypersensitivity, and 4th group treated with oral administration of butterbur extract one-day post to the hypersensitivity induction. Ovalbumin induces a significant increase in the activity of liver enzymes and MDA and decreased the activity of CAT after the ovalbumin treatment. Histopathological investigations revealed marked pathological alterations in liver tissues in the form of hyaline degeneration and fibrosis. Additionally, heavy immune response indicated by immunostaining of MDA and TNF-α could be observed. In contrast, posttreatment with butterbur extract after hypersensitivity induction resulted in a significant decrease of liver enzymes and oxidative stress and reduced the inflammation and fibrosis of liver tissues. These results suggest that butterbur extract is considered as anti-inflammatory and antioxidant therapeutic herb for hypersensitivity treatment of liver.

Size and time-dependent induction of proinflammatory cytokines expression in brains of mice treated with gold nanoparticles.

Gold nanoparticles (GNPs) are among the ideal nano-sized materials for medical applications such as imaging and drug delivery. Considering the significance of recent reports on acute phase induction of inflammatory mediators by GNPs, we studied the effect of GNPs on proinflammatory cytokines gene expression in mouse brain. Group 1 served as control whereas groups 2-4 were given only one intraperitoneal dose of 5, 20 and 50 nm GNPs, respectively and sacrificed after 24 h. The animals in groups 5-7 also received the same treatment but sacrificed after 7 days. Groups 8-10 received two injections of GNPs (5, 20 and 50 nm, respectively), first at the beginning of study and second on day 6, and sacrificed on day 7. Total RNA was extracted from the cerebral tissue and analyzed for the gene expressions of IL-1ß, IL-6 and TNF-α. A single injection of 5 nm diameter GNPs significantly increased the mRNA expression of IL-1ß and IL-6 in mouse brain on day 7, which was not augmented by the second dose of the same GNPs. Larger size GNPs (20 nm and 50 nm) did not cause any significant change in the expression of proinflammatory cytokines in mouse brain. In conclusion, systemic administration of small sized GNPs (5 nm) induced a proinflammatory cascade in mouse brain indicating a crucial role of GNPs size on immune response. It is important to use the right sized GNPs in order to avoid an acute phase inflammatory response that could be cytotoxic or interfere with the bioavailability of nanomaterials.

Antioxidant effects of captopril against lead acetate-induced hepatic and splenic tissue toxicity in Swiss albino mice.

Considering that lead caused a lot of health problems in the world, the present study was carried out to investigate the protective effect of captopril as antioxidants to reduce liver and spleen toxicity induced by lead. Animals were divided into 3 groups, the 1st group served as control group, the 2nd group received 20 mg/kg of lead acetate and the 3rd group received 50 mg/kg of captopril one hour prior to lead administration for 5 days. Results showed that lead intake caused severe alterations in the liver and spleen manifested by hepatocytes degeneration, leukocytic infiltration, fibrosis in liver and moderate to severe liver pathological score. Spleen showed ill-defined architecture, presence of large macrophages and lymphoid necrosis. Administration of captopril reduced hepatotoxicity, liver fibrosis and decrease in pathological scoring system. Moreover, reduced toxicity in spleen is represented by reduction in necrotic areas, more or less healthy lymphoid follicles and decreasing in pathological scoring system.

Biotin amelioration of nephrotoxicity in streptozotocin-induced diabetic mice.

The current study was carried out to investigate the protective role of biotin in kidney injury and oxidative stress in diabetic mice type 1. Male Swiss albino mice were randomly divided into 3 groups. Control group received saline. Diabetes type 1 was induced in second and third groups by intraperitoneal injection of streptozotocin as a single dose (150 mg/kg). Second group remained as the untreated diabetic group and the third group received 15 mg/kg daily oral dose of biotin for 12 successive days. Biochemical results showed significant elevation in blood glucose and urea levels in both diabetic groups. Also, there is an increase in glomerular areas and decrease in glomerular cellularity in both diabetic groups. Histopathological results showed severe alterations in the untreated diabetic group represented by distorted glomeruli, inflammatory cells, and giant macrophages. In addition, there was an intense immune-reaction response toward acrolein indicator of oxidative damage. Upon biotin administration of diabetic mice, the above mentioned histopathological changes were reduced and also acroline reaction of oxidative damage was diminished. Our findings prove that biotin has a protective role against streptozotocin-induced oxidative damage in kidneys of laboratory mice.