Rejina Afrin

Modulation of HMGB1 translocation and RAGE/NFκB cascade by quercetin treatment mitigates atopic dermatitis in NC/Nga transgenic mice.

Quercetin, glycosylated form of flavonoid compound, has potent antioxidant and anti‐inflammatory properties. In this study, we have investigated the effects of quercetin on skin lesion, high‐mobility group box (HMGB)1 cascade signalling and inflammation in atopic dermatitis (AD) mouse model. AD‐like lesion was induced by the application of house dust mite extract to the dorsal skin of NC/Nga transgenic mouse. After AD induction, quercetin (50 mg/kg, p.o) was administered daily for 2 weeks. We evaluated dermatitis severity, histopathological changes and changes in protein expression by Western blotting for HMGB1, receptor for advanced glycation end products (RAGE), toll‐like receptor (TLR)4, nuclear factor (NF)κB, nuclear factor erythroid‐2‐related factor (Nrf)2, kelch‐like ECH‐associated protein (Keap)1, extracellular signal‐regulated kinase (ERK)1/2, cyclooxygenase (COX)2, tumor necrosis factor (TNF)α, interleukin (IL)‐1β, IL‐2Rα and other inflammatory markers in the skin of AD mice. In addition, serum levels of T helper (Th) cytokines (interferon (IFN)γ, IL‐4) were measured by enzyme‐linked immunosorbent assay. Quercetin treatment attenuated the development of AD‐like skin lesions. Histological analysis showed that quercetin inhibited hyperkeratosis, parakeratosis, acanthosis, mast cells and infiltration of inflammatory cells. Furthermore, quercetin treatment downregulated cytoplasmic HMGB1, RAGE, nuclear p‐NFκB, p‐ERK1/2, COX2, TNFα, IL‐1β, IL‐2Rα, IFNγ and IL‐4 and upregulated nuclear Nrf2. Our data demonstrated that the HMGB1/RAGE/NFκB signalling might play an important role in skin inflammation, and quercetin treatment could be a promising agent for AD by modulating the HMGB1/RAGE/NFκB signalling and induction of Nrf2 protein.

Curcumin ameliorates streptozotocin-induced liver damage through modulation of endoplasmic reticulum stress-mediated apoptosis in diabetic rats

Abstract We investigated the effect of curcumin on liver injury in diabetic rats induced by streptozotocin (STZ) through modulation of endoplasmic reticulum stress (ERS) and unfolded protein response (UPR). Experimental diabetes was induced by a single intraperitoneal injection of STZ (55 mg/kg), and curcumin was given at 100 mg/kg by gavage for 56 days. We observed that curcumin improved the morphological and histopathological changes, significantly decreased hepatic ERS marker protein: glucose-regulated protein 78, and improved liver function in diabetic rats. Moreover, treatment with curcumin markedly decreased the sub-arm of the UPR signaling protein such as phospho–double-stranded RNA-dependent protein kinase-like ER kinase, CCAAT/enhancer-binding protein homologous protein, tumor necrosis factor receptor-associated factor 2, and inositol-requiring enzyme1α; and inhibited tumor necrosis factor α, interleukin 1β, phospho-p38 mitogen-activated protein kinase, and apoptosis signal-regulating kinase 1 in liver tissues of diabetic rats. Apoptotic and anti-apoptotic signaling proteins, such as cleaved caspase-3 and B-cell lymphoma 2, were significantly increased and decreased, respectively in diabetic rats; curcumin treatment prevented all of these alterations. In summary, our results indicate that curcumin has the potential to protect the diabetic liver by modulating hepatic ERS-mediated apoptosis, and provides a novel therapeutic strategy for the diabetic liver damage.

Naringenin ameliorates daunorubicin induced nephrotoxicity by mitigating AT1R, ERK1/2-NFκB p65 mediated inflammation.

Inflammation and oxidative stress play important roles in the progression of renal damage. The natural polyphenol naringenin is known to exert potent antioxidant and anti-inflammatory effects. In this study, we have investigated the effect of naringenin on kidney dysfunction, fibrosis, endoplasmic reticulum (ER) stress, angiotensin II type I receptor (AT1R) expression and inflammation in daunorubicin (DNR) induced nephrotoxicity model. Nephrotoxicity was induced in rats by intravenous injection of DNR at a cumulative dose of 9 mg/kg. After 1 week, naringenin (20mg/kg/day. p.o) was administered daily for 6 weeks. Biochemical studies were performed to evaluate renal function. Western blotting was performed to measure the protein levels of AT1R, endothelin (ET)1, ET receptor type A (ETAR), extracellular signal-regulated kinase (ERK)1/2, nuclear factor (NF)κB p65, peroxisome proliferator activated receptor (PPAR)γ, oxidative/ER stress, apoptosis, and inflammatory markers in the kidney of DNR treated rats. Histopathological analysis was done using hemotoxylin eosin and Masson trichrome stained renal sections to investigate the structural abnormalities and fibrosis. DNR treated rats suffered from nephrotoxicity as evidenced by worsened renal function, increased blood urea nitrogen, serum creatinine levels in renal tissues and histopathogical abnormalities. Treatment with naringenin mitigated these changes. Furthermore, naringenin up regulated PPARγ and down regulated AT1R, ET1, ETAR, p-ERK1/2, p-NFκB p65, ER stress, apoptosis, and inflammatory markers. Our results suggest that naringenin has an ability to improve renal function and attenuates AT1R, ERK1/2-NFκB p65 signaling pathway in DNR induced nephrotoxicity in rats.

Tannic acid modulates NFκB signaling pathway and skin inflammation in NC/Nga mice through PPARγ expression

Polyphenolic compound tannic acid, which is mainly found in grapes and green tea, is a potent antioxidant with anticarcinogenic activities. In this present study, we hypothesized that tannic acid could inhibit nuclear factor (NF)κB signaling and inflammation in atopic dermatitis (AD) NC/Nga mice. We have analyzed the effects of tannic acid on dermatitis severity, histopathology and expression of inflammatory signaling proteins in house dust mite extract induced AD mouse skin. In addition, serum levels of T helper (Th) cytokines (interferon (IFN)γ, interleukin (IL)-4) were measured by enzyme-linked immunosorbent assay. Treatment with tannic acid ameliorated the development of AD-like clinical symptoms and effectively inhibited hyperkeratosis, parakeratosis, acanthosis, mast cells and infiltration of inflammatory cells in the AD mouse skin. Serum levels of IFNγ and IL-4 were significantly down-regulated by tannic acid. Furthermore, tannic acid treatment inhibited DfE induced tumor necrosis factor (TNF)α, high mobility group protein (HMG)B1, receptor for advanced glycation end products (RAGE), extracellular signal-regulated kinase (ERK)1/2, NFκB, cyclooxygenase (COX)2, IL-1β and increased the protein expression of peroxisome proliferator-activated receptor (PPAR)γ. Taken together, our results demonstrate that, DfE induced skin inflammation might be mediated through NFκB signaling and tannic acid may be a potential therapeutic agent for AD, which may possibly act via induction of PPARγ protein.

Curcumin ameliorates liver damage and progression of NASH in NASH-HCC mouse model possibly by modulating HMGB1-NF-κB translocation

&NA; Curcumin, a phenolic compound, has a wide spectrum of therapeutic effects such as antitumor, anti‐inflammatory, anti‐cancer and so on. The study aimed to investigate the underlying mechanisms of curcumin to protect liver damage and progression of non‐alcoholic steatohepatitis (NASH) in a novel NASH‐hepatocellular carcinoma (HCC) mouse model. To induce this model neonatal C57BL/6J male mice were exposed to low‐dose streptozotocin and were fed a high‐fat diet (HFD) from the age of 4 weeks to 14 weeks. Curcumin was given at 100 mg/kg dose daily by oral gavage started at the age of 10 weeks and continued until 14 weeks along with HFD feeding. We found that curcumin improved the histopathological changes of the NASH liver via reducing the level of steatosis, fibrosis associated with decreasing serum aminotransferases. In addition, curcumin treatment markedly reduced the hepatic protein expression of oxidative stress, pro‐inflammatory cytokines, and chemokines including interferon (IFN) &ggr;, interleukin‐1&bgr; and IFN&ggr;‐inducible protein 10, in NASH mice. Furthermore, curcumin treatment significantly reduced the cytoplasmic translocation of high mobility group box 1 (HMGB1) and the protein expression of toll like receptor 4. Nuclear translocation of nuclear factor kappa B (NF‐&kgr;B) was also dramatically attenuated by the curcumin in NASH liver. Curcumin treatment effectively reduced the progression of NASH to HCC by suppressing the protein expression of glypican‐3, vascular endothelial growth factor, and prothrombin in the NASH liver. Our data suggest that curcumin reduces the progression of NASH and liver damage, which may act via inhibiting HMGB1‐NF‐&kgr;B translocation. HighlightsNASH‐HCC mouse model involves the increased HMGB1 and NF‐&kgr;B translocation.In this model, oxidative stress and inflammation were significantly increased.It involves the activation of lipogenesis and fibrosis in NASH liver.Curcumin treatment reduced these oxidative stress, inflammation and lipogenesis.Curcumin markedly attenuated fibrosis, HMGB1‐NF‐&kgr;B translocation and its signaling.

Curcumin alleviates renal dysfunction and suppresses inflammation by shifting from M1 to M2 macrophage polarization in daunorubicin induced nephrotoxicity in rats.

The molecular mechanism of curcumin in macrophage polarization remains unknown in renal failure. We examined, whether curcumin treatment is associated with the modulation of renal function and macrophage phenotype switch in daunorubicin (DNR) induced nephrotoxicity model. Sprague-Dawley rats were treated with a cumulative dose of 9mg/kg DNR (i.v). Followed by curcumin (100mg/kg) administration orally every day for 6weeks. DNR treated rats showed nephrotoxicity as evidenced by worsening renal function, which was assessed by measuring creatinine and blood urea nitrogen in serum. These changes were reversed by treatment with curcumin, which resulted in significant improvement in renal function. Furthermore, curcumin increased cluster of differentiation (CD)163 expression, and down-regulated renal expression of antigen II type I receptor (AT1R), endothelin (ET)1, ET receptor type A and B (ETAR and ETBR), CD68 and CD80. Renal protein expression of extracellular signal-regulated kinase (ERK)1/2 and nuclear factor (NF)κB p65 were increased in DNR treated rats, and treatment with curcumin attenuated these increased expression. Curcumin mediated a further increase in the levels of interleukin (IL)-10. In addition, the expression of M1 phenotype was increased in DNR treated rats, which were attenuated by curcumin. Taken together, our results demonstrated that polyphenol curcumin has an ability to improve renal function and might induce the phenotypic switching from M1 to M2 macrophage polarization in DNR induced nephrotoxicity in rats.

Myocardial 14-3-3η protein protects against mitochondria mediated apoptosis.

There is a definite cardioprotective role for 14-3-3η protein against pressure overload induced cardiac hypertrophy and streptozotocin induced cardiac dysfunction in type 1 diabetes mellitus (DM). But it is not conclusive whether it has any influence on mitochondrial mediated cardiomyocyte apoptosis in type 2 DM. In order to test this hypothesis, we have used C57BL6/J (WT) mice with cardiac specific dominant negative mutation of 14-3-3η protein (DN 14-3-3η). Both WT and DN 14-3-3η mice were fed with high fat diet (HFD) for 12weeks. Their body weight and blood glucose levels were measured weekly and compared with standard diet (SD) fed mice. By the end of 12weeks, echocardiography was performed. Frozen myocardial sections were prepared to stain the apoptotic cardiomyocytes using TUNEL staining. DN 14-3-3η mice fed with HFD showed cardiac dysfunction as identified by the decreased fractional shortening and ejection fraction and increased cardiomyocyte apoptosis in TUNEL staining. Western blotting analysis using mitochondrial fraction of the ventricular tissue homogenates showed a significant reduction in the level of cytochrome c suggesting its translocation into cytoplasm, which may be crucial in inducing cardiomyocyte apoptosis. In addition, DN 14-3-3η mice depicted significantly increased levels of NADPH oxidase subunits suggesting oxidative stress, a significant reduction in phospho apoptosis signal-regulating kinase-1 (p-Ask-1) and increase in Ask-1 and phospho c-Jun N-terminal kinase (p-JNK) levels suggesting activation of Ask-1/JNK signaling. These results suggest that 14-3-3η has a protective role against mitochondria mediated cardiomyocyte apoptosis with the involvement of Ask-1/JNK signaling during HFD induced type 2 DM.

Naringenin ameliorates skin inflammation and accelerates phenotypic reprogramming from M1 to M2 macrophage polarization in atopic dermatitis NC/Nga mouse model

mentation successfully reversed the aberrations associated with impairment of acidic homoeostasis (Fig. 2f), supporting the possible therapeutic role of ACVR1C stimulation in sensitive skin. Conclusions Taken together, our findings not only show reduced expression of ACVR1C in sensitive skin but also demonstrate that ACVR1C plays crucial roles in the pathogenesis of sensitive skin, and the activation of these signalling pathways in vitro successfully reversed pain pathways in RD cells, thereby raising the possibility of a novel therapeutic approach for sensitive skin. Further studies are warranted to find novel chemicals or natural compounds to improve sensitive skin by activating ACVR1C pathway effectively and safely. Acknowledgements This study was supported by a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (grant number: HI14C1277). Author contributions EJK, YKK and YML performed the experiments. EJK, DHL, HCE and JHC designed the study, analysed the data and wrote the manuscript. Conflicts of interest The authors declare no conflicting interest. Supporting Information

Pruni cortex ameliorates skin inflammation possibly through HMGB1-NFκB pathway in house dust mite induced atopic dermatitis NC/Nga transgenic mice

Pruni cortex, the bark of Prunus jamasakura Siebold ex Koidzumi, has been used in the Japanese systems of medicine for many years for its anti-inflammatory, antioxidant and antitussive properties. In this study, we investigated the effect of pruni cortex on atopic dermatitis NC/Nga mouse model. Atopic dermatitis-like lesion was induced by the application of house dust mite extract to the dorsal skin. After induction of atopic dermatitis, pruni cortex aqueous extract (1 g/kg, p.o.) was administered daily for 2 weeks. We evaluated dermatitis severity, histopathological changes and cellular protein expression by Western blotting for nuclear and cytoplasmic high mobility group box 1, receptor for advanced glycation end products, nuclear factor κB, apoptosis and inflammatory markers in the skin of atopic dermatitis mice. The clinical observation confirmed that the dermatitis score was significantly lower when treated with pruni cortex than in the atopic dermatitis group. Similarly pruni cortex inhibited hypertrophy and infiltration of inflammatory cells as identified by histopathology. In addition, pruni cortex significantly inhibited the protein expression of cytoplasmic high mobility group box 1, receptor for advanced glycation end products, nuclear p-nuclear factor kappa B, apoptosis and inflammatory markers. These results indicate that pruni cortex may have therapeutic potential in the treatment of atopic dermatitis by attenuating high mobility group box 1 and inflammation possibly through the nuclear factor κB pathway.

Comparative evaluation of torasemide and furosemide on rats with streptozotocin-induced diabetic nephropathy

Nephropathy is one of the complications of diabetes mellitus in human and experimental animals. There are various pathological renal remodeling processes leading to diabetic nephropathy because of the chronic hyperglycemia during diabetes mellitus. Various reports suggest the involvement of oxidative stress, inflammation and fibrosis during this progression. As antihypertensive drugs are reported to provide renoprotection in various animal models and clinical studies, we have carried out this study to identify the effect of torasemide, a loop diuretic, against streptozotocin-induced diabetic nephropathy and compare with furosemide. Here we have performed the measurement of blood and urine parameters and renal protein expression levels for measuring the disease severity in streptozotocin-induced diabetic rats treated torasemide or furosemide and compared with the vehicle treated rats. Furosemide treatment significantly increased the urinary protein excretion when compared with the normal rats. Torasemide treatment has reduced the expression of mineralocorticoid receptor and oxidative stress marker p67phox levels with improved mRNA levels of heme oxygenase-1 in the kidneys. In addition, torasemide treated diabetic rats showed significantly reduced expression of renal fibrosis related proteins when compared with the vehicle treated diabetic rats. Although furosemide treatment has produced improvement, its effects are comparably less than that of torasemide. Thus with the present results, we can suggest that torasemide treatment can improve the diabetic kidney disease in this rat model and which is superior to furosemide against renal fibrotic remodeling.