Reversal of deleterious effect of hypertension on the liver by inhibition of endoplasmic reticulum stress.

Hypertension is an important risk factor for cardiovascular diseases. Besides cardiovascular system, it could cause damage to liver. It has been shown that endoplasmic reticulum stress (ERS) plays a crucial role in the pathogenesis of hypertension. ERS inhibitor tauroursodeoxycholic-acid (TUDCA) has favorable effects on various pathologies including cardiovascular, metabolic and hepatic diseases. In this study, the hepatoprotective effect and mechanism of TUDCA were investigated in the deoxycorticosterone acetate (DOCA)-salt-induced hypertension. Male Wistar rats were used and divided into four groups: Control, DOCA, TUDCA and DOCA + TUDCA. Hypertension was induced by DOCA-salt administration for twelve weeks after the unilateral nephrectomy. TUDCA was given for the last 4 weeks. Systolic blood pressure was measured by using tail-cuff method. At the end of the treatment, liver was isolated and weighed. The expressions of various proteins and histopathological evaluation were examined in the liver. TUDCA markedly decreased systolic blood pressure in the hypertensive animals. Hypertension caused increase in the expressions of glucose-regulated protein-78 (GRP78), matrix metalloproteinase-2 (MMP-2) and phospho-inhibitor κB-α (p-IκB-α) and the decrease in the expression of sarcoplasmic/endoplasmic reticulum Ca2+-ATPase2 (SERCA2) and phospho-extracellular signal-regulated kinase (p-ERK) in the liver. Alterations in these protein expressions were not detected in the TUDCA-treated hypertensive group. Also, hepatic balloon degeneration, inflammation and fibrosis were observed in the hypertensive group. TUDCA improved inflammation and fibrosis in the hypertensive liver. Our findings indicate that the detrimental effect of DOCA-salt-induced hypertension on the liver was defended by the inhibition of ERS. Hepatic ERS and its treatment should be taken into consideration for therapeutic approaches to hypertension.

Resveratrol affects histone 3 lysine 27 methylation of vessels and blood biomarkers in DOCA salt-induced hypertension.

Hypertension is a risk factor for the cardiovascular diseases. Although, several drugs are used to treat hypertension, the success of the antihypertensive therapy is limited. Resveratrol decreases blood pressure in animal models of hypertension. This study researched the mechanisms behind the effects of resveratrol on hypertension. Hypertension was induced by using the deoxycorticosterone acetate (DOCA)-induced (15 mg/kg twice per week, subcutaneously) salt-sensitive hypertension model of Wistar rats. Hypertension caused a decrease in endothelium-dependent relaxations of the isolated thoracic aorta. Resveratrol treatment (50 mg/l in drinking water) prevented DOCA salt-induced hypertension, but did not improve endothelial dysfunction. Plasma nitric oxide (NO), asymmetric dimethylarginine (ADMA), total antioxidant capacity (TAC) and hydrogen sulfide (H2S) levels were not changed by DOCA salt application. However, treatment of resveratrol significantly decreased ADMA and increased TAC and H2S levels. NO level in circulation was not significantly changed by resveratrol. DOCA salt application and resveratrol treatment also caused an alteration in the epigenetic modification of vessels. Staining pattern of histone 3 lysine 27 methylation (H3K27me3) in the aorta and renal artery sections was changed. These results show that preventive effect of resveratrol on DOCA salt-induced hypertension might due to its action on the production of some blood biomarkers and the epigenetic modification of vessels that would focus upon new aspect of hypertension prevention and treatment.

Investigation of the relationship between inflammation and microbiota in the intestinal tissue of female and male rats fed with fructose: Modulatory role of metformin.

BACKGROUND: It has been reported that High-Fructose (HF) consumption, considered one of the etiological factors of Metabolic Syndrome (MetS), causes changes in the gut microbiota and metabolic disorders. There is limited knowledge on the effects of metformin in HF-induced intestinal irregularities in male and female rats with MetS. OBJECTIVES: In this study, we investigated the sex-dependent effects of metformin treatment on the gut microbiota, intestinal Tight Junction (TJ) proteins, and inflammation parameters in HF-induced MetS. METHODS: Fructose was given to the male and female rats as a 20% solution in drinking water for 15 weeks. Metformin (200 mg/kg) was administered by gastric tube once a day during the final seven weeks. Biochemical, histopathological, immunohistochemical, and bioinformatics analyses were performed. Differences were considered statistically significant at p < 0.05. RESULTS: The metformin treatment in fructose-fed rats promoted glucose, insulin, Homeostasis Model Assessment of Insulin Resistance Index (HOMA-IR), and Triglyceride (TG) values in both sexes. The inflammation score was significantly decreased with metformin treatment in fructose-fed male and female rats (p < 0.05). Moreover, metformin treatment significantly decreased Interleukin-1 Beta (IL-1ß) and Tumor Necrosis Factor-Alpha (TNF-α) in ileum tissue from fructose-fed males (p < 0.05). Intestinal immunoreactivity of Occludin and Claudin-1 was increased with metformin treatment in fructose-fed female rats. HF and metformin treatment changed the gut microbial composition. Firmicutes/Bacteroidetes (F/B) ratio increased with HF in females. In the disease group, Bifidobacterium pseudolongum; in the treatment group, Lactobacillus helveticus and Lactobacillus reuteri are the prominent species in both sexes. When the male and female groups were compared, Akkermansia muciniphila was prominent in the male treatment group. CONCLUSION: In conclusion, metformin treatment promoted biochemical parameters in both sexes of fructose-fed rats. Metformin showed a sex-dependent effect on inflammation parameters, permeability factors, and gut microbiota. Metformin has partly modulatory effects on fructose-induced intestinal changes.

The anti-inflammatory effect of diclofenac is considerably augmented by topical capsaicinoids-containing patch in carrageenan-induced paw oedema of rat.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most used drugs in musculoskeletal disorders, but their systemic adverse effects limit their therapeutic benefit in local inflammation. On the other hand, topical preparations of capsaicinoids are widely used for musculoskeletal disorders as a complementary therapy. In this study, the effects of both topical capsaicinoids-containing patch and local subcutaneous capsaicin application on the anti-inflammatory action of NSAID were examined. Carrageenan-induced paw oedema of rats was used as the inflammation model. The volume and weight of the paw oedema and plasma extravasation in the paw were determined after carrageenan injection. The systemic application of diclofenac (3 mg/kg), which is an NSAID, significantly decreased the volume and weight of the paw oedema. Topical capsaicinoids-containing patch application or local capsaicin injection (2, 10, 20 µg/paw) alone did not cause any effect on oedema volume and weight. However, the combination of diclofenac with topical capsaicinoids-containing patch significantly increased the effectiveness of diclofenac on inflammation. Evans blue content of the paws that represents plasma extravasation was decreased by capsaicinoids-containing patch with and without diclofenac and diclofenac combination with the lowest dose of capsaicin injection. The results of this study indicate that topical application of capsaicinoids-containing patch enhances the anti-inflammatory effect of diclofenac and its beneficial effect may not purely relate to its capsaicin content. In the treatment of local inflammatory disorders, the combination of NSAID with topical capsaicinoids-containing patch could increase the anti-inflammatory efficiency of drug without systemic side effects.

Resveratrol and regular exercise may attenuate hypertension-induced cardiac dysfunction through modulation of cellular stress responses.

AIMS: Hypertension is one of the major causes of cardiac damage. In this study, the effects of resveratrol supplementation and regular exercise on hypertension-induced cellular stress responses of myocardium were compared. MAIN METHODS: Hypertension was induced in male Wistar rats by deoxycorticosterone-acetate + salt administration for 12 weeks. Resveratrol and regular exercise were applied for the last six weeks. In addition to biochemical and molecular examinations, isoprenaline, phenylephrine and, acetylcholine-mediated contractions and sinus rate were recorded in the isolated cardiac tissues. KEY FINDINGS: Resveratrol and regular exercise reduced systolic blood pressure in hypertensive rats. The altered adrenergic and cholinergic responses of the right atrium and left papillary muscles in hypertension were separately improved by resveratrol and regular exercise. Resveratrol and regular exercise decreased plasma and cardiac total antioxidant capacity and, augmented the expression of antioxidant genes in hypertensive rats. While regular exercise restored the increase in p-PERK expression associated with endoplasmic reticulum stress and decrease in mitophagic marker PINK1 expression, resveratrol only ameliorated PINK1 expression in hypertensive rats. Resveratrol and exercise training suppressed hypertension-induced NLRP3 inflammasome activation by reversing the increase in NLRP3, p-NF-κB expression and the mature-IL-1ß/pro-IL-1ß and cleaved-caspase-1/pro-caspase-1 ratio. Resveratrol and exercise enhanced mRNA expression of caspase-3, bax, and bcl-2 involved in the apoptotic pathway, but attenuated phosphorylation of stress-related mitogenic proteins p38 and JNK induced by hypertension. SIGNIFICANCE: Our study demonstrated the protective effect of resveratrol and exercise on hypertension-induced cardiac dysfunction by modulating cellular stress responses including oxidative stress, ER stress, mitophagy, NLRP3 inflammasome-mediated inflammation, and mitogenic activation.

Effects of Resveratrol on Receptor Expression and Serum Levels of Estrogen and Progesterone in the Rat Endometritis Model.

Endometritis is characterized by inflammation of the endometrial lining that leads to reduced reproductive potential. Restoring the impaired hormonal balance is an important component of endometritis treatment. The purpose of the current study was to evaluate the effects of resveratrol on estrogen and progesterone hormone status in endometritis. Mature female Sprague Dawley rats were used, and endometritis was induced by intrauterine infusion of Escherichia coli. Animals were treated with resveratrol alone or combined with marbofloxacin. Compared to the non-treated endometritis group, resveratrol treatment reduced serum oestradiol levels, increased serum progesterone levels, enhanced estrogen receptor (ER) expression in the uterine stroma, decreased ESR1 gene expression, and raised ESR2 gene expression. Resveratrol administration combined with marbofloxacin also increased ER expression in the uterine gland and progesterone receptor expression in the uterine epithelium. The findings of this study suggest that the actions of resveratrol on progesterone levels and estrogen receptor expression might be responsible for its beneficial effect in rats with endometritis.

Therapeutic effects of resveratrol in Escherichia coli-induced rat endometritis model.

Endometritis is an inflammatory disorder of the endometrial lining of the uterine tissue in postpartum stage. Endometritis mostly progresses subclinically and causes infertility through the disruption of the hormonal balance. It has been shown in many studies that resveratrol has anti-inflammatory and antioxidant properties. However, the possible beneficial effects of resveratrol in endometritis have not been determined yet. The aim of the present study is to evaluate the treatment potential of resveratrol in an experimentally induced endometritis model in rats. Endometritis was induced in 12-week-old female, nonpregnant, Sprague Dawley rats. The animals were divided into six groups: control (NaCl 0.9%) and endometritis (NaCl 0.9%), marbofloxacin + PGF2α, marbofloxacin, marbofloxacin + resveratrol, and resveratrol groups. To induce endometritis, 5 mg/kg/s.c. progesterone was given for 5 days, and then Escherichia coli (50 µl, 1 × 105 cfu/rat) was injected in the right cornu uteri following laparotomy. Sixteen hours after bacterial inoculation, the treatment protocol was applied for 14 days. At the end of the experiment, the total oxidant status (TOS) and total antioxidant status (TAS) were examined spectrophotometrically in uterus tissues. The severity of inflammation in uterus samples and follicular activity in ovarian tissues were histopathologically evaluated. In addition, serum cytokine levels were determined. While TAS in uterine tissue significantly increased in the resveratrol group when compared to that of the other groups (p < 0.05), there was no difference between the groups in TOS (p > 0.05). The inflammation of the endometrium and the numbers of corpus luteum in the endometritis group were highly significant when compared to those of the other groups (p < 0.05). The recovery of inflammation and follicular activity were similar to those of the other groups in resveratrol group. However, it was realized that resveratrol administration reduced serum cytokine levels. According to the results of the current study, resveratrol was found to be effective in the treatment of endometritis with its antioxidant and anti-inflammatory functions.

Inhibition of endoplasmic reticulum stress protected DOCA-salt hypertension-induced vascular dysfunction.

Hypertension has complex vascular pathogenesis and therefore the molecular etiology remains poorly elucidated. Endoplasmic reticulum stress (ERS), which is a condition of the unfolded/misfolded protein accumulation in the endoplasmic reticulum, has been defined as a potential target for cardiovascular disease. In the present study, the effects of ERS inhibition on hypertension-induced alterations in the vessels were investigated. In male Wistar albino rats, hypertension was induced through unilateral nephrectomy, deoxycorticosterone-acetate (DOCA) injection (20 mg/kg, twice a week) and 1% NaCl with 0.2% KCI added to drinking water for 12 weeks. An ERS inhibitor, tauroursodeoxycolic acid (TUDCA) (150 mg/kg/day, i.p.), was administered for the final four weeks. ERS inhibition in DOCA-salt induced hypertension was observed to have reduced systolic blood pressure, improved endothelial dysfunction, enhanced plasma nitric oxide (NO) level, reduced protein expressions of phosphorylated-double-stranded RNA-activated protein kinase-like endoplasmic reticulum kinase (pPERK), 78 kDa glucose-regulated protein (GRP78), Inositol trisphosphate receptor1 (IP3R1) and Epidermal growth factor receptor (EGFR), increased expressions of endoplasmic reticulum Ca2+-ATPase2 (SERCA2) and B cell lymphoma2 (Bcl2) in vessels. These findings suggest that the beneficial effects of ERS inhibition on hypertension may be related to protection of vessel functions through restoration of endoplasmic reticulum calcium homeostasis, and apoptotic and mitotic pathways.

The effects of LXR agonist GW3965 on vascular reactivity and inflammation in hypertensive rat aorta.

AIMS: Liver X receptors (LXRs) play an important role in the regulation of cholesterol, fatty acid and glucose metabolisms together with inflammatory processes. In the present study, the effects of LXR agonist GW3965 on vascular reactivity and expression of functional proteins in DOCA-Salt induced hypertension were examined. MAIN METHODS: Hypertension was induced through unilateral nephrectomy and deoxycorticosterone-acetate (DOCA) injection (20 mg/kg, twice a week) for 6 weeks in male Wistar albino rats (8 weeks old). An LXR agonist GW3965 (10 mg/kg/day, i.p.) was administered to animals for last seven days. KEY FINDINGS: GW3965 treatment reduced systolic blood pressures in hypertensive rats. Acetylcholine-induced endothelium-dependent and sodium nitroprusside-induced endothelium-independent vasorelaxations were decreased in hypertensive rats but not affected by GW3965. GW3965 treatment enhanced plasma nitrite levels in normotensive rats. KCl and phenylephrine (Phe)-induced vasocontractions were reduced in hypertensive groups and increased with GW3965 treatment. Decreased sarco/endoplasmic reticulum Ca2+-ATPase2 (SERCA2) expression in the hypertensive aorta was not changed by GW3965 treatment. Expression of inositoltrisphosphate receptor1 (IP3R1) was increased by GW3965 in normotensive animals. The nuclear factor kappaB (NF-κB) and tumor necrosis factor alpha (TNF-α) expressions were increased in hypertensive rats and reduced by GW3965 treatment. SIGNIFICANCE: The results of study indicate that the LXR agonist, GW3965, exhibited a beneficial effect on increased blood pressure and improved hypertension-induced impairment in contractile activity of vessel and inflammatory markers in vascular tissue. Therefore, these effects of LXR agonists on vessel should be taken into account in experimental or therapeutic approaches to hypertension.

Age- and sex-dependent alteration of functions and epigenetic modifications of vessel and endothelium related biomarkers.

Aging is a main risk factor for development of cardiovascular diseases associated with the impairment of endothelial function in both sexes. In the present study, age-related changes in vascular responsiveness, epigenetic modifications of vessel wall, and blood biomarkers related to endothelial functions were examined in an age- and sex-dependent manner. Acetylcholine (ACh)-induced relaxations of the aorta were decreased in 3-, 6-, and 12-month-old rats compared to those in 1-month-old female rats. In males, maximum relaxations related to ACh were higher in 1- and 6-month-old rats than in 3- and 12-month-old rats. Plasma levels of nitric oxide (NO) and asymmetric dimethylarginine (ADMA) decreased with age in female rats, and total antioxidant capacity (TAC) and hydrogen sulfide (H 2S) levels displayed biphasic alterations. In male rats, plasma levels of NO, TAC, and ADMA decreased with age, and H2S levels increased. Aging also caused a sex-dependent alteration in epigenetic modification of vessels. Expressions of H3K27me2, H3K27me3, H3K36me2, and H3K36me3 were much higher in vessels of 12-month-old female rats compared to those in younger age groups. These results indicate that vascular functions, epigenetic modifications of vessels, and plasma levels of endothelium-related biomarkers are affected by age and sex. These findings could be important for the assessment of vascular status over the course of the life span.

Development of controlled release dexketoprofen tablets and prediction of drug release using Artificial Neural Network (ANN) modelling

Dexketoprofen trometamol (DT) is an active S (+) enantiomer of ketoprofen, and a non-steroidal anti-inflammatory agent. DT has a short biological half-life and the dosing interval is quite short when there is a need to maintain the desirable effect for longer time periods. Consequently, a controlled release DT tablet was designed for oral administration aiming to minimize the number of doses and the possible side effects. Calculations of the parameters for controlled release DT tablets were shown clearly. Controlled release matrix-type tablet formulations were prepared using hydroxypropyl methylcellulose (HPMC) (low and high viscosity), Eudragit RS and Carbopol, and the effects of different polymers on DT release from the tablet formulations were investigated. The dissolution rate profiles were compared and analyzed kinetically. An Artificial Neural Network (ANN) model was developed to predict drug release and a successful model was obtained. Subsequently, an optimum formulation was selected and evaluated in terms of its analgesic and anti-inflammatory activity. Although the developed controlled release tablets did not have an initial dose, they were found to be as effective as commercially available tablets on the market. Dissolution and in vivo studies have shown that the prepared tablets were able to release DT for longer time periods, making the tablets more effective, convenient and more tolerable.