The ameliorative effect of kaempferol against CdCl2- mediated renal damage entails activation of Nrf2 and inhibition of NF-kB.

This study evaluated the nephroprotective effect of kaempferol against cadmium chloride (CdCl2) -induced nephropathy in rats. It also investigated if activation of Nrf2 is a common mechanism of action. Adult male rats ((150 ± 15 g) were divided into 4 groups (n = 8/each) as a control (1% DMSO, orally), control + kaempferol (200 mg/kg, orally), CdCl2 (50 mg/l in drinking water), and CdCl2 + kaempferol (200 mg/kg)-treated rats. All treatments were conducted for 8 weeks. Kaempferol significantly attenuated CdCl2-induced weight loss, reduction in kidney weights, and the injury in the glomeruli, proximal tubules, and distal tubules in the treated rats. It also significantly lowered serum levels of urea and creatinine, increased urine output and urinary creatinine levels and clearance but reduced urinary levels of albumin urinary albumin exertion (UAER), and urinary albumin/creatinine ratio (UACR) in these rats. In parallel, kaempferol downregulated renal levels of cleaved caspase-3 and Bax and unregulated those of Bcl2. In the kidney tissues of the control animals and CdCl2 rats, kaempferol significantly attenuated oxidative stress, inflammation and significantly boosted levels of manganese superoxide dismutase and glutathione. Also, and in both groups, kaempferol suppressed the nuclear levels of NF-κB p65, downregulated Keap1, and stimulated the nuclear activation and protein levels of Nrf2. In conclusion, kaempferol is a potential therapeutic drug to prevent CdCl2-induced nephropathy due to its anti-inflammatory and anti-oxidant effects mediated by suppressing NF- NF-κB p65 and transactivating Nrf2.

Exercise augments the modulatory effects of vitamin E on pre-diabetes-induced aortopathy: a potential role of adiponectin.

Background: We tested the hypothesis that vitamin E may protect against pre-diabetes-induced aortic injury (aortopathy), and exercise can augment the action of vitamin E.Material and methods: Rats were either fed with a high fat and fructose diet (HFD) (model group) or a standard laboratory chow (control group) for 15 weeks before being sacrificed. The three protective groups were treated with vitamin E (HFD + Vit E), swimming exercises (HFD + Ex), and vitamin E plus swimming exercises (HFD + VitE + Ex), respectively.Results: Aortopathy was developed in the model group as demonstrated by substantial tissue ultrastructural alterations, which were partially protected by vitamin E and effectively protected with vitamin E plus swim exercise. Also, swimming exercises significantly (p < .05) increased the modulatory effects of vitamin E on dyslipidemia, insulin resistance, blood pressure, oxidative stress, inflammation, leptin, and adiponectin, except coagulation and thrombosis.Conclusions: Swim exercise augments the protective effects of vitamin E in a pre-diabetic animal model.

Acylated ghrelin induces but deacylated ghrelin prevents hepatic steatosis and insulin resistance in lean rats: Effects on DAG/ PKC/JNK pathway.

This study investigated the molecular effects of acylated (AG) and unacylated ghrelin (UAG) or their combination on hepatic lipogenesis pathways and DAG/PKC/JNK signaling in the livers of lean rats fed standard diet. Male rats (n = 10) were classified as control + vehicle (saline, 200 µl), AG, UAG, and AG + UAG-treated groups. All treatments were given at final doses of 200 ng/kg of for 14 days (twice/day, S.C). Administration of AG significantly enhanced circulatory levels of AG and UAG turning the normal ratio of AG/UAG from 1:2.5 to 1:1.2. However, while UAG didn't affect circulatory levels of AG, administration of UAG alone or in combination with AG resulted in AG/UAG ratios of 1:7 and 1:3, respectively. Independent of food intake nor the development of peripheral IR, AG increased hepatic DAG, TGs and CHOL contents and induced hepatic IR. Mechanism of action include 1) upregulation of mRNA and protein levels of DGAT-2 and mtGPAT-1, SREBP-1 and SCD-1, and 2) inhibition of fatty acids (FAs) oxidation mediated by inhibition of AMPK/ PPAR-α/CPT-1 axis. Consequently, AG induced membranous translocation of PKCδ and PKCε leading to activation of JNK and significant inhibition of insulin signaling under basal and insulin stimulation as evident by decreases in the phosphorylation levels of IRS (Tyr612) and Akt (Thr318) and increased phosphorylation of IRS (Ser307). However, while UAG only activated FAs oxidation in control rats, it reversed all alterations in all measured biochemical endpoints seen in the AG-treated group, when administered in combination with AG, leading to significant decreases in hepatic fat accumulation and prevention of hepatic IR. In conclusion, while exogenous administration of AG is at high risk of developing steatohepatitis and hepatic IR, co-administration of a balanced dose of UAG reduces this risk and inhibits hepatic lipid accumulation and enhance hepatic insulin signaling.

Suppression of high fat diet-induced liver cell injury by swim exercise / Supresión de lesión en células de hígado inducida por dieta alta en grasas con ejercicio de natación

SUMMARY: The rapid rise in obesity, particularly among children is a major public health concern that adversely affects vital organs including the liver. We sought to investigate the effect of exercise on the healing of liver cells from damage induced by high fat diet (HFD) in a rat model of hepatic steatosis. Rats were randomly divided into four groups (n=6 in each group); control group fed on a low fat diet (LFD), LFD plus exercise group (LFD+EX), model group fed on HFD, and swim exercise treated group (HFD+EX). Training swim exercise started from the 11th week up until the end of week 15. Liver index and body mass index (BMI) were determined, and harvested liver tissues were examined using basic histological staining and visualised under light microscopy. In addition, collected blood samples were assayed for biomarkers of liver injury. Histological images from the model group showed accumulation of lipid droplets in the hepatocytes (steatosis) and damaged liver cells that were inhibited by swimming exercise. Compared to control groups, HFD caused an increase in BMI and liver weight but not in liver index. In addition, HFD significantly (p<0.05) increased liver injury biomarkers; high-sensitivity C-reactive protein (hsCRP) and alkaline phosphatase (ALP) that were effectively (p<0.05) decreased by swimming exercise. Furthermore, a negative correlation between these biomarkers and the antioxidant and anti-inflammatory protein adiponectin was observed. Thus, HFD-induced hepatic steatosis is treated by swim exercise.

RESUMEN: El aumento de la obesidad, especialmente entre los niños, es un problema importante en la salud pública que afecta negativamente los órganos vitales, incluyendo el hígado. En este estudio se investigó el efecto del ejercicio en la curación de las células del hígado y el daño inducido por la dieta alta en grasas (HFD) en un modelo de rata de esteatosis hepática. Las ratas se dividieron aleatoriamente en cuatro grupos (n = 6 en cada grupo); grupo control, alimentado con una dieta baja en grasas (LFD); grupo de ejercicio LFD más (LFD + EX); grupo modelo alimentado con HFD; y grupo tratado con ejercicio de natación (HFD + EX). El entrenamiento con ejercicio de natación comenzó a partir de la semana 11 hasta el final de la semana 15. Se determinaron el índice hepático y el índice de masa corporal (IMC). Los tejidos hepáticos recolectados se examinaron mediante tinción histológica básica y se visualizaron con microscopía óptica. Además, se analizaron las muestras de sangre recogidas para identificar biomarcadores de lesión hepática. Las imágenes histológicas del grupo modelo mostraron acumulación de gotitas de lípidos en los hepatocitos (esteatosis) y células hepáticas dañadas que fueron inhibidas por el ejercicio de natación. En comparación con los grupos control, HFD causó un aumento en el IMC y el peso del hígado, pero no en el índice de hígado. Además, HFD aumentó significativamente (p <0.05) los biomarcadores de lesiones hepáticas; la proteína C reactiva de alta sensibilidad (hsCRP) y la fosfatasa alcalina (ALP) disminuyeron efectivamente (p <0.05) con el ejercicio de natación. Además, se observó una correlación negativa entre estos biomarcadores y la proteína antioxidante y antiinflamatoria adiponectina. Por lo tanto, la esteatosis hepática inducida por HFD puede ser tratada mediante el ejercicio de natación.

Cardioprotective effect of ghrelin against myocardial infarction-induced left ventricular injury via inhibition of SOCS3 and activation of JAK2/STAT3 signaling.

The molecular mechanisms through which ghrelin exerts its cardioprotective effects during cardiac remodeling post-myocardial infarction (MI) are poorly understood. The aim of this study was to investigate whether the cardioprotection mechanisms are mediated by modulation of JAK/STAT signaling and what triggers this modulation. Rats were divided into six groups (n = 12/group): control, sham, sham + ghrelin (100 µg/kg, s.c., daily, starting 1 day post-MI), MI, MI+ ghrelin, and MI+ ghrelin+ AG490, a potent JAK2 inhibitor (5 mg/kg, i.p., daily). All treatments were administered for 3 weeks. Administration of ghrelin to MI rats improved left ventricle (LV) architecture and restored cardiac contraction. In remote non-infarcted areas of MI rats, ghrelin reduced cardiac inflammation and lipid peroxidation and enhanced antioxidant enzymatic activity. In addition, independent of the growth factor/insulin growth factor-1 (GF/IGF-1) axis, ghrelin significantly increased the phosphorylation of JAK2 and Tyr702 and Ser727 residues of STAT3 and inhibited the phosphorylation of JAK1 and Tyr701 and Ser727 residues of STAT1, simultaneously increasing the expression of BCL-2 and decreasing in the expression of BAX, cleaved CASP3, and FAS. This effect coincided with decreased expression of SOCS3. All these beneficial effects of ghrelin, except its inhibitory action on IL-6 expression, were partially and significantly abolished by the co-administration of AG490. In conclusion, the cardioprotective effect of ghrelin against MI-induced LV injury is exerted via activation of JAK2/STAT3 signaling and inhibition of STAT1 signaling. These effects were independent of the GF/IGF-1 axis and could be partially mediated via inhibition of cardiac IL-6.

Acute exposure to Catha edulis depresses contractility and induces myocardial infarction in spontaneously contracting, isolated rabbit's heart.

Khat chewing is a recreational habit known to pose major socio-economic and medical problems in countries of Southern Arabia and the Horn of Africa. Among other adverse health effects, khat chewing has been associated with an increased risk of myocardial infarction (MI) in heavy consumers. This study was carried out to examine the direct effects of Catha edulis extract on contractility of spontaneously contracting, isolated rabbit heart and to investigate its mechanism of action. Isolated six rabbit's hearts attached to a Langendorff apparatus were perfused with extract at a constant flow rate and continuously bubbled with a 95% O2/5% CO2 gas mixture. Each heart served as its own control, as responses were recorded before and after administration of C. edulis extract. Varying concentrations of extract (50, 100 and 250 mg/ml) were loaded in the perfusate, their effects recorded and effluent fluid collected for assay of cardiac enzymes. Histological examination of the cardiac tissue was performed at the end of perfusion with 250 mg/ml extract. This study revealed that acute exposure to C. edulis extract exerted negative inotropic and chronotropic effects on isolated hearts. The extract also had a vasoconstrictor effect on coronary vessels, independent of α1 adrenergic receptor stimulation. Histological examination of hearts perfused with 250 mg/ml C. edulis extract revealed the presence of histological changes unique to myocardial infarction, a finding consistent with observed increased levels of cardiac enzymes in perfusates. Thus, we have demonstrated experimentally a direct cardiac depressant- and MI inducing effects of C. edulis extract. These results are consistent with the earlier reported deleterious effects of khat on cardiovascular function among khat chewers.

In vivo acute effects of orally administered hydro-ethanol extract of Catha edulis on blood glucose levels in normal, glucose-fed hyperglycemic, and alloxan-induced diabetic rats.

OBJECTIVE: To investigate the blood glucose lowering effect of khat (Catha edulis) extract in normal, glucose-loaded, and alloxan diabetic rats. METHODS: Three experimental protocols were used in this study. In each of the first 2 protocols, 3 groups of rats (6 rats per group) were used as control group (NS), Catha edulis (CE) treated, and glibenclamide treated groups. This study was carried out at the Physiological Laboratory of the Medical School of King Khalid University, Abha, Saudi Arabia between October and November, 2009. Normal rats were used in the first protocol while alloxan diabetic rats were used in the second protocol. Blood glucose levels were measured in all 3 groups after single dose injections of saline, CE or glibenclamide. In the third protocol, another 6 groups of rats (6 rats per group) were prepared as in the first 2 protocols and oral glucose tolerance test (OGTT) was performed on each rat after oral administration of glucose (1.5 g/kg). RESULTS: Oral administration of a hydro-ethanol extract of CE caused no statistically significant change in blood glucose levels in normal rats with or without glucose loading. There were slight, non significant increases in blood glucose levels of extract-treated diabetic rats, with and without glucose loading, as compared to the corresponding untreated rats. CONCLUSION: Oral administration of CE extract does not exert a hypoglycemic effect in normal, glucose-loaded, and diabetic rats.

The influence of pulmonary receptors on respiratory drive in a rabbit model of pulmonary emphysema.

We have observed that pulmonary rapidly adapting receptor activity is greater in emphysematous rats than in controls. Pulmonary receptor activity, if modified by lung disease, may produce an inappropriate drive to breathe which may be perceived as dyspnoea. To investigate the efferent (drive) component of this hypothesis respiratory drive (phrenic nerve activity) was recorded in a rabbit model of emphysema. Drive was measured as slope and peak height of phrenic nerve activity. Slope and peak height were greater in emphysematous rabbits than controls, by 28% and 34%, respectively. Block of slowly adapting pulmonary stretch receptors by inhaled sulphur dioxide (which left only rapidly adapting and C-fibre receptors active) decreased drive in control (slope: 38.89+/-2.29 to 24.09+/-1.26, P<0.01) but not emphysematous rabbits (slope: 49.92+/-4.11 to 54.51+/-5.28, NS). Subsequent vagotomy decreased drive in emphysematous rabbits (slope: 54.51+/-5.28 to 41.41+/-3.90, P<0.05) but not controls (24.09+/-1.26 to 23.07+/-1.84, NS). Increased rapidly adapting receptor activity may, in part, increase respiratory drive in emphysema. This vagal component is only part of the total increased drive which may be perceived as dyspnoea in man.