Tumor necrosis factor-alpha: a possible priming agent for the polymorphonuclear leukocyte-reduced nicotinamide-adenine dinucleotide phosphate oxidase in hypertension

Effects of intrarenal pelvic infusion of tumour necrosis factor-α and interleukin 1-β on reno-renal reflexes in anaesthetised rats

OBJECTIVE

Reno-renal reflexes are disturbed in cardiovascular and hypertensive conditions when elevated levels of pro-inflammatory mediators/cytokines are present within the kidney. We hypothesised that exogenously administered inflammatory cytokines tumour necrosis factor alpha (TNF-α) and interleukin (IL)-1β modulate the renal sympatho-excitatory response to chemical stimulation of renal pelvic sensory nerves.

METHODS

In anaesthetised rats, intrarenal pelvic infusions of vehicle [0.9% sodium chloride (NaCl)], TNF-α (500 and 1000 ng/kg) and IL-1β (1000 ng/kg) were maintained for 30 min before chemical activation of renal pelvic sensory receptors was performed using randomized intrarenal pelvic infusions of hypertonic NaCl, potassium chloride (KCl), bradykinin, adenosine and capsaicin.

RESULTS

The increase in renal sympathetic nerve activity (RSNA) in response to intrarenal pelvic hypertonic NaCl was enhanced during intrapelvic TNF-α (1000 ng/kg) and IL-1β infusions by almost 800% above vehicle with minimal changes in mean arterial pressure (MAP) and heart rate (HR). Similarly, the RSNA response to intrarenal pelvic adenosine in the presence of TNF-α (500 ng/kg), but not IL-1β, was almost 200% above vehicle but neither MAP nor HR were changed. There was a blunted sympatho-excitatory response to intrapelvic bradykinin in the presence of TNF-α (1000 ng/kg), but not IL-1β, by almost 80% below vehicle, again without effect on either MAP or HR.

CONCLUSION

The renal sympatho-excitatory response to renal pelvic chemoreceptor stimulation is modulated by exogenous TNF-α and IL-1β. This suggests that inflammatory mediators within the kidney can play a significant role in modulating the renal afferent nerve-mediated sympatho-excitatory response.

Modulation of TNF-α, interleukin-6, and interleukin-10 by nebivolol-valsartan and nebivolol-lisinopril polytherapy in SHR rats

Antihypertensive drug therapies have demonstrated their capacity to modulate the inflammatory processes associated with hypertension, leading to improvements in disease progression. Given the prevalent use of polytherapy in treating most hypertensive patients, comprehending the time-dependent effects of combination treatments on inflammation becomes imperative. In this study, spontaneously hypertensive rats (SHR) were divided into seven groups (n = 6): (i) SHR + vehicle, (ii) SHR + nebivolol, (iii) SHR + valsartan, (iv) SHR + lisinopril, (v) SHR + nebivolol-valsartan, (vi) SHR + nebivolol-lisinopril, and (vii) WKY + vehicle. Blood pressure was measured using the tail-cuff method. Temporal alterations in inflammatory cytokines TNF-α, IL-6, and IL-10 were assessed in serum through ELISA and mRNA expression in aortic tissue via qPCR after 1, 2, and 4 weeks of treatment with nebivolol, lisinopril, valsartan, and their respective combinations. Histological alterations in the aorta were assessed. The findings indicated that combined treatments reduced systolic and diastolic blood pressure in SHR. The nebivolol and lisinopril combination demonstrated a significant decrease in IL-6 serum and mRNA expression at both 1 week and 4 weeks into the treatment. Additionally, TNF-α mRNA expression also showed a reduction with this combination at the same time points. Particularly, nebivolol-valsartan significantly decreased TNF-α serum and mRNA expression after one and four weeks of treatment. Furthermore, an elevation in serum IL-10 levels was observed with both combination treatments starting from the second week onwards. This study provides compelling evidence that concurrent administration of nebivolol with lisinopril or valsartan exerts time-dependent effects, reducing proinflammatory cytokines TNF-α and IL-6 while modifying IL-10 levels in an experimental hypertensive model.

Association between Psoriasis and Renal Functions: An Integration Study of Observational Study and Mendelian Randomization

Psoriasis is an autoimmune-mediated disease with several comorbidities in addition to typical skin lesions. Increasing evidence shows the relationships between psoriasis and renal functions, but the relationship and causality remain unclear. We aimed to investigate the associations and causality between psoriasis and four renal functions, including the estimated glomerular filtration rate (eGFR), blood urea nitrogen (BUN), urine albumin to creatinine ratio (UACR), and chronic kidney disease (CKD). For the population-based study, we analyzed the National Health and Nutrition Examination Survey (NHANES) data from five cycles (2003-2006 and 2009-2014) on psoriasis and renal functions. Subgroup analyses were conducted among different categories of participants. Meanwhile, a bidirectional two-sample Mendelian randomization (TSMR) study in European populations was also performed using summary-level genetic datasets. Causal effects were derived by conducting an inverse-variance weighted (MR-IVW) method. A series of pleiotropy-robust MR methods was employed to validate the robustness. Multivariable MR (MVMR) was conducted to complement the result when five competing risk factors were considered. A total of 20,244 participants were enrolled in the cross-sectional study, where 2.6% of them had psoriasis. In the fully adjusted model, participants with psoriasis had significantly lower eGFR (p = 0.025) compared with the healthy group. Individuals who are nonoverweight are more likely to be affected by psoriasis, leading to an elevation of BUN (Pint = 0.018). In the same line, TSMR showed a negative association between psoriasis and eGFR (p = 0.016), and sensitive analysis also consolidated the finding. No causality was identified between psoriasis and other renal functions, as well as the inverse causality (p > 0.05). The MVMR method further provided quite consistent results when adjusting five confounders (p = 0.042). We detected a significant negative effect of psoriasis on eGFR, with marginal association between BUN, UACR, and CKD. The adverse of psoriasis on the renal should merit further attention in clinical cares.

Interaction between Butyrate and Tumor Necrosis Factor α in Primary Rat Colonocytes

Butyrate, a short-chain fatty acid, is utilized by the gut epithelium as energy and it improves the gut epithelial barrier. More recently, it has been associated with beneficial effects on immune and cardiovascular homeostasis. Conversely, tumor necrosis factor alpha (TNFα) is a pro-inflammatory and pro-hypertensive cytokine. While butyrate and TNFα are both linked with hypertension, studies have not yet addressed their interaction in the colon. Here, we investigated the capacity of butyrate to modulate a host of effects of TNFα in primary rodent colonic cells in vitro. We measured ATP levels, cell viability, mitochondrial membrane potential (MMP), reactive oxygen species (ROS), mitochondrial oxidative phosphorylation, and glycolytic activity in colonocytes following exposure to either butyrate or TNFα, or both. To address the potential mechanisms, transcripts related to oxidative stress, cell fate, and cell metabolism (Pdk1, Pdk2, Pdk4, Spr, Slc16a1, Slc16a3, Ppargc1a, Cs, Lgr5, Casp3, Tnfr2, Bax, Bcl2, Sod1, Sod2, and Cat) were measured, and untargeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) was employed to profile the metabolic responses of colonocytes following exposure to butyrate and TNFα. We found that both butyrate and TNFα lowered cellular ATP levels towards a quiescent cell energy phenotype, characterized by decreased oxygen consumption and extracellular acidification. Co-treatment with butyrate ameliorated TNFα-induced cytotoxicity and the reduction in cell viability. Butyrate also opposed the TNFα-mediated decrease in MMP and mitochondrial-to-intracellular calcium ratios, suggesting that butyrate may protect colonocytes against TNFα-induced cytotoxicity by decreasing mitochondrial calcium flux. The relative expression levels of pyruvate dehydrogenase kinase 4 (Pdk4) were increased via co-treatment of butyrate and TNFα, suggesting the synergistic inhibition of glycolysis. TNFα alone reduced the expression of monocarboxylate transporters slc16a1 and slc16a3, suggesting effects of TNFα on butyrate uptake into colonocytes. Of the 185 metabolites that were detected with LC-MS, the TNFα-induced increase in biopterin produced the only significant change, suggesting an alteration in mitochondrial biogenesis in colonocytes. Considering the reports of elevated colonic TNFα and reduced butyrate metabolism in many conditions, including in hypertension, the present work sheds light on cellular interactions between TNFα and butyrate in colonocytes that may be important in understanding conditions of the colon.

Tumor Necrosis Factor Alpha and the Gastrointestinal Epithelium: Implications for the Gut-Brain Axis and Hypertension

The colonic epithelium is the site of production and transport of many vasoactive metabolites and neurotransmitters that can modulate the immune system, affect cellular metabolism, and subsequently regulate blood pressure. As an important interface between the microbiome and its host, the colon can contribute to the development of hypertension. In this critical review, we highlight the role of colonic inflammation and microbial metabolites on the gut brain axis in the pathology of hypertension, with special emphasis on the interaction between tumor necrosis factor α (TNFα) and short chain fatty acid (SCFA) metabolites. Here, we review the current literature and identify novel pathways in the colonic epithelium related to hypertension. A network analysis on transcriptome data previously generated in spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats reveals differences in several pathways associated with inflammation involving TNFα (NF-κB and STAT Expression Targets) as well as oxidative stress. We also identify down-regulation of networks associated with gastrointestinal function, cardiovascular function, enteric nervous system function, and cholinergic and adrenergic transmission. The analysis also uncovered transcriptome responses related to glycolysis, butyrate oxidation, and mitochondrial function, in addition to gut neuropeptides that serve as modulators of blood pressure and metabolic function. We present a model for the role of TNFα in regulating bacterial metabolite transport and neuropeptide signaling in the gastrointestinal system, highlighting the complexity of host-microbiota interactions in hypertension.

Agave tequilana Counteracts Chronic Hypertension and Associated Vascular Damage

Systemic arterial hypertension (SAH) is a health problem of great importance worldwide, and endothelial dysfunction underlies SAH development. This condition's main characteristics include vasoconstriction, inflammation, oxidative stress, and procoagulant and proliferative states. This study's objective was to evaluate the antihypertensive, anti-inflammatory, and antioxidant effects of the whole extract and fractions of Agave tequilana in a murine model of SAH. SAH was induced in male ICR or CD-1 (Strain obtained from animals from Charles River Laboratories, Massachusetts) mice by intraperitoneal administration of angiotensin II (AGII) (0.1 μg/kg) for 4 weeks, and then A. tequilana treatments were co-administered with AGII. At the end of the experiment, systolic and diastolic blood pressure were measured and the kidneys were dissected to quantify interleukin (IL)-1β, IL-6, tumor necrosis factor-alpha, IL-10, and malondialdehyde (MDA). The whole extract and the fractions of A. tequilana were chemically characterized using gas chromatography-mass spectrometry. The results indicate that the whole extract (At-W) and At-AcOEt fraction treatment are the most efficient in lowering blood pressure, although all the treatments had an immunomodulatory effect on the cytokines evaluated and an antioxidant effect on lipid peroxidation. Finally, the chromatographic profile shows that the integral extract and fractions of A. tequilana contained phytol (M)3,7,11,15-Tetramethyl-2-hexadecen-1-ol; 9,12-octadecadienoic acid; hentriacontane; 9,19-cyclolanost-24-en-3-ol,(3b); t-sitosterol; and stigmasta-3,5-dien-7-one.

Inhibitory effects of telmisartan on culture and proliferation of and Kv1.3 potassium channel expression in peripheral blood CD4+ T lymphocytes from Xinjiang Kazakh patients with hypertension

INTRODUCTION

Activation of T lymphocytes, for which potassium channels are essential, is involved in the development of hypertension. In this study, we explored the inhibitory effects of telmisartan on the culture and proliferation of and Kv1.3 potassium channel expression in peripheral blood CD4+ T lymphocytes derived from Xinjiang Kazakh patients with hypertension.

METHODS

CD4+ T-cell samples from hypertensive Kazakh patients and healthy Kazakh people were divided into healthy control, case control, telmisartan, and 4-aminopytidine groups. Changes in the expression levels of interleukin (IL)-6 and IL-17 in the blood of the healthy control and case control subjects were detected by enzyme-linked immunosorbent assay. Peripheral blood CD4+ T lymphocytes were first activated and proliferated in vitro and then incubated for 0, 24, and 48 h under various treatment conditions. Thereafter, changes in CD4+ T-lymphocytic proliferation were determined using Cell Counting Kit-8 and microscope photography. Changes in messenger RNA (mRNA) and protein expression of the Kv1.3 potassium channel in CD4+ T lymphocytes were detected using real-time quantitative polymerase chain reaction and Western blots, respectively.

RESULTS

The IL-6 and IL-17 expression levels were significantly higher in the blood of the hypertensive Kazakh patients than in the healthy Kazakh people. Telmisartan inhibited T-lymphocytic proliferation, as well as the mRNA and protein expression of the Kv1.3 potassium channel in CD4+ T lymphocytes, and the inhibitory effects were time-dependent, with the strongest inhibition observed after 48 h and significantly weaker inhibition observed after 24 h of treatment.

CONCLUSIONS

Telmisartan may potentially regulate hypertensive inflammatory responses by inhibiting T-lymphocytic proliferation and Kv1.3 potassium channel expression in CD4+ T lymphocytes.

Effects of Yishen Pinggan Recipe on Renal Protection and NF-κB Signaling Pathway in Spontaneously Hypertensive Rats

Inflammation is an important etiological factor of hypertensive renal damage. The effects of Yishen Pinggan Recipe (YPR) on urine microalbumin, histology, and NF-κB/P65, IκB-α, IL-1β, IL-6, and TNF-α in renal tissues were evaluated in SHR to explore the mechanism of its renal protection in hypertensive renal damage. The SBP of 12-week-old SHR was 192.41 ± 3.93 mmHg and DBP was 142.38 ± 5.79 mmHg. Without treatment, the 24-week-old SHRs' SBP was 196.96 ± 3.77 mmHg and DBP was 146.08 ± 4.82 mmHg. After the 12-week-old SHR were administered YPR for 12 weeks, the rats' SBP was 161.45 ± 7.57 mmHg and DBP was 117.21 ± 5.17 mmHg; YPR could lower blood pressure in SHR. And renal function damage was observed in 24-week-old SHR without treatment, manifested as urine protein and morphological changes which could be inhibited by YPR. In addition, YPR could reduce the expression of inflammatory cytokines (IL-1β, IL-6, and TNF-α) in kidneys. It could also inhibit the nuclear translocation of NF-κB p65 and degradation of IκB-α in renal cells, indicating that the NF-κB signaling pathway was inhibited by YPR. Finally, the study suggests that YPR could significantly improve the renal function in SHR. The mechanism could be attributed to its inhibition of renal NF-κB signaling pathway and inflammation.

The role of oxidative stress, antioxidants and vascular inflammation in cardiovascular disease (a review)

The concept of mild chronic vascular inflammation as part of the pathophysiology of cardiovascular disease, most importantly hypertension and atherosclerosis, has been well accepted. Indeed there are links between vascular inflammation, endothelial dysfunction and oxidative stress. However, there are still gaps in our understanding regarding this matter that might be the cause behind disappointing results of antioxidant therapy for cardiovascular risk factors in large-scale long-term randomised controlled trials. Apart from the limitations of our knowledge, limitations in methodology and assessment of the body's endogenous and exogenous oxidant-antioxidant status are a serious handicap. The pleiotropic effects of antioxidant and anti-inflammation that are shown by some well-established antihypertensive agents and statins partly support the idea of using antioxidants in vascular diseases as still relevant. This review aims to provide an overview of the links between oxidative stress, vascular inflammation, endothelial dysfunction and cardiovascular risk factors, importantly focusing on blood pressure regulation and atherosclerosis. In view of the potential benefits of antioxidants, this review will also examine the proposed role of vitamin C, vitamin E and polyphenols in cardiovascular diseases as well as the success or failure of antioxidant therapy for cardiovascular diseases in clinical trials.

Perivascular adipose tissue, vascular reactivity and hypertension

Most blood vessels are surrounded by a variable amount of adventitial adipose tissue, perivascular adipose tissue (PVAT), which was originally thought to provide mechanical support for the vessel. It is now known that PVAT secretes a number of bioactive substances including vascular endothelial growth factor, tumor necrosis factor-alpha (TNF-α), leptin, adiponectin, insulin-like growth factor, interleukin-6, plasminogen activator substance, resistin and angiotensinogen. Several studies have shown that PVAT significantly modulated vascular smooth muscle contractions induced by a variety of agonists and electrical stimulation by releasing adipocyte-derived relaxing (ADRF) and contracting factors. The identity of ADRF is not yet known. However, several vasodilators have been suggested including adiponectin, angiotensin 1-7, hydrogen sulfide and methyl palmitate. The anticontractile effect of PVAT is mediated through the activation of potassium channels since it is abrogated by inhibiting potassium channels. Hypertension is characterized by a reduction in the size and amount of PVAT and this is associated with the attenuated anticontractile effect of PVAT in hypertension. However, since a reduction in size and amount of PVAT and the attenuated anticontractile effect of PVAT were already evident in prehypertensive rats with no evidence of impaired release of ADRF, there is the possibility that the anticontractile effect of PVAT was not directly related to an altered function of the adipocytes per se. Hypertension is characterized by low-grade inflammation and infiltration of macrophages. One of the adipokines secreted by macrophages is TNF-α. It has been shown that exogenously administered TNF-α enhanced agonist-induced contraction of a variety of vascular smooth muscle preparations and reduced endothelium-dependent relaxation. Other procontractile factors released by the PVAT include angiotensin II and superoxide. It is therefore possible that the loss could be due to an increased amount of these proinflammatory and procontractile factors. More studies are definitely required to confirm this.

Discovery and evaluation of novel anti-inflammatory derivatives of natural bioactive curcumin

Curcumin is a natural active product that has various pharmacological activities such as anti-inflammatory effects. Here, we report the synthesis and evaluation of 34 monocarbonyl curcumin analogs as novel anti-inflammatory agents. Among the analogs, the symmetrical heterocyclic type displayed the strongest inhibition of lipopolysaccharide (LPS)-stimulated expression of pro-inflammatory cytokines in macrophages. Analogs S1–S5 and AS29 reduced tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) production in a dose-dependent manner and also displayed excellent stability and low cytotoxicity in vitro. In addition, analog S1 dose-dependently inhibited LPS-induced extracellular signal-regulated kinase (ERK) phosphorylation. Furthermore, analogs S1 and S4 displayed a significant protective effect on LPS-induced septic death in mouse models, with 40% and 50% survival rates, respectively. These data demonstrate that the heterocyclic monocarbonyl curcumin analogs have potential therapeutic effects in acute inflammatory diseases.

Immune cell dysfunction and inflammation in end-stage renal disease

Uraemia causes inflammation and reduces immune system function as evidenced by an increased risk of viral-associated cancers, increased susceptibility to infections and decreased vaccination responses in patients with end-stage renal disease (ESRD). The substantially increased risk of atherosclerosis in these patients is also probably related to uraemia-associated inflammation. Uraemia is associated with a reduction in the number and function of lymphoid cells, whereas numbers of myeloid cells in uraemic patients are normal or increased with increased production of inflammatory cytokines and reactive oxygen species. Similar to healthy elderly individuals, patients with ESRD have increased numbers of specific proinflammatory subsets of T cells and monocytes, suggesting the presence of premature immunological ageing in these patients. These cells might contribute to inflammation and destabilization of atherosclerotic plaques, and have, therefore, been identified as novel nonclassical cardiovascular risk factors. The cellular composition of the immune system does not normalize after successful kidney transplantation despite a rapid reduction in inflammation and oxidative stress. This finding suggests that premature ageing of the immune system in patients with ESRD might be related to a permanent skewing of the haematopoetic stem cell population towards myeloid-generating subsets, similar to that seen in healthy elderly individuals.

A novel synthetic mono-carbonyl analogue of curcumin, A13, exhibits anti-inflammatory effects in vivo by inhibition of inflammatory mediators

Curcumin is a pleiotropic molecule against inflammatory related diseases. However, poor bioavailability greatly limits its application in clinic. Our previous study synthesized and evaluated a hydrosoluble mono-carbonyl analogue of curcumin, (2E,5E)-2,5-bis(4-(3-(dimethylamino)-propoxy)benzylidene)cyclopentanone (A13). In the present study, we further evaluated the anti-inflammatory effect of A13 in vivo. In lipopolysaccharide-challenged mice, pretreatment of A13 (15 mg/kg, i.v.) attenuated the increase of plasma level of NO, TNF-α, and IL-6, significantly inhibited the increase of hepatic inflammatory gene transcription, and improved pulmonary damages. In addition, A13 (10 or 30 mg/kg, i.p.) reduced vascular permeability in Institute of Cancer Research mice and inhibited pain reaction in chemically induced inflammatory models. Together, A13 exhibits anti-inflammatory activities both in vitro and in vivo by the inhibition of various inflammatory mediators.

The importance of myeloperoxidase in apocynin-mediated NADPH oxidase inhibition

Apocynin is widely used as an inhibitor of the NADPH oxidase. Since myeloperoxidase (MPO) has been considered as essential for the mechanism of action of apocynin, here we used cells with different levels of MPO and compared their sensitivity to apocynin. HL-60 cells were differentiated with DMSO or IFNγ/TNFα and compared with peripheral mononuclear (PBMC) and polymorphonuclear cells (PMN). The relative MPO activity was PBMC = HL60 DMSO < HL60 IFNγ < PMN. Apocynin inhibited the intracellular reactive oxygen species production by PMN (80%) and IFNγ/TNFα-differentiated HL-60 cells (45%) but showed a minor effect in PBMC and DMSO differentiated HL-60 cells (20%). The addition of azide decreased the efficiency of apocynin in PMN and the addition of peroxidase increased the inhibition in PBMC. We also determined the gene expression of the components gp91phox, p47phox, p22phox and p67phox in the resting cells. Apocynin did not change gp91phox, p47phox or p22phox gene expression in nonstimulated PBMC, HL60 DMSO, HL60 IFNγ/TNFα, and PMN and has a subtle increase in p67phox in HL60 IFNγ/TNFα. The results from this work suggest that a rational search for better inhibitors of NADPH oxidase in leukocytes should include a correlation with their affinity as substrates for MPO.

Tumor necrosis factor-alpha g308α gene polymorphism and essential hypertension: a meta-analysis involving 2244 participants

Background

The tumor necrosis factor-alpha (TNFα) G308A gene polymorphism has been implicated in susceptibility to essential hypertension (EH), but study results are still controversial.

Objective and Methods

The present meta-analysis is performed to investigate the relationship between the TNFα G308A gene polymorphism and EH. Electronic databases were searched and seven separate studies on the association of the TNF α G308A gene polymorphism with EH were analyzed. The meta-analysis involved 1092 EH patients and 1152 controls. The pooled odds ratios (ORs) and their corresponding 95% confidence interval (CI) were calculated by a fixed or random effect model.

Results

A significant relationship between the TNFα G308A gene polymorphism and EH was found in an allelic genetic model (OR: 1.45, 95% CI: 1.17 to 1.80, P = 0.0008), a recessive genetic model (OR: 3.181, 95% CI: 1.204 to 8.408, P = 0.02), and a homozygote model (OR: 3.454, 95% CI: 1.286 to 9.278, P = 0.014). No significant association between them was detected in both a dominant genetic model (OR: 1.55, 95% CI: 0.99 to 2.42, P = 0.06) or a heterozygote genetic model (OR: 1.45, 95% CI: 0.90 to 2.33, P = 0.13).

Conclusion

The TNFα G308A gene polymorphism is associated with EH susceptibility.

Evaluation and discovery of novel synthetic chalcone derivatives as anti-inflammatory agents

Major anti-inflammatory agents, steroids and cyclooxygenase, were proved to have serious side effects. Here, a series of chalcone derivatives were synthesized and screened for anti-inflammatory activities. QSAR study revealed that the presence of electron-withdrawing groups in B-ring and electron-donating groups in A-ring of chalcones was important for inhibition of LPS-induced IL-6 expression. Further, compounds 22, 23, 26, 40, and 47 inhibited TNF-α and IL-6 release in a dose-dependent manner and decreased LPS-induced TNF-α, IL-1β, IL-6, IL-12, and COX-2 mRNA production. Mechanistically, compounds 23 and 26 interfered with JNK/NF-κB signaling and dose-dependently prevented ERK and p38 activation. In addition, 23 and 26 exhibited a significant protection against LPS-induced death and were able to block high glucose-activated cytokine profiles in macrophages. Together, these data show a series of anti-inflammatory chalcones with potential therapeutic effects in inflammatory diseases.

Mechanisms and consequences of salt sensitivity and dietary salt intake

PURPOSE OF REVIEW

Investigation into the underlying mechanisms of salt sensitivity has made important advances in recent years. This review examines in particular the effects of sodium and potassium on vascular function.

RECENT FINDINGS

Sodium chloride (salt) intake promotes cutaneous lymphangiogenesis mediated through tissue macrophages and directly alters endothelial cell function, promoting increased production of transforming growth factor-β (TGF-β) and nitric oxide. In the setting of endothelial dysfunction, such as occurs with aging, diminished nitric oxide production exacerbates the vascular effects of TGF-β, promoting decreased arterial compliance and hypertension. Dietary potassium intake may serve as an important countervailing influence on the effects of salt in the vasculature.

SUMMARY

There is growing appreciation that, independently of alterations in blood pressure, dietary intake of sodium and potassium promotes functional changes in the vasculature and lymphatic system. These changes may protect against development of salt-sensitive hypertension. While salt sensitivity cannot be ascribed exclusively to these factors, perturbation of these processes promotes hypertension during high-salt intake. These studies add to the list of genetic and environmental factors that are associated with salt sensitivity, but in particular provide insight into adaptive mechanisms during high salt intake.

Synthesis and anti-inflammatory evaluation of novel mono-carbonyl analogues of curcumin in LPS-stimulated RAW 264.7 macrophages

Curcumin is a multifunctional natural product with regulatory effects on inflammation. However, a major limitation for the application of curcumin is its poor bioavailability. We previously demonstrated that the mono-carbonyl analogues of curcumin possessed improved pharmacokinetic profiles. In this study, 33 novel mono-carbonyl analogues of curcumin were synthesized and their inhibition against TNF-α and IL-6 release was evaluated in LPS-stimulated RAW 264.7 macrophages. Based on the screening data, quantitative structure-activity relationship was conducted, indicating that electron-withdrawing groups in benzene ring are favourable to anti-inflammatory activities of B-class compounds. Furthermore, compounds AN1 and B82 demonstrated anti-inflammatory abilities in a dose-dependent manner. These raise the possibility that these compounds might serve as potential agents for the treatment of inflammatory diseases.