Paraventricular Nucleus Infusion of Oligomeric Proantho Cyanidins Improves Renovascular Hypertension

Natural polyphenols as novel interventions for aging and age-related diseases: Exploring efficacy, mechanisms of action and implications for future research

Natural polyphenols are a group of components widely found in traditional Chinese medicines and have been demonstrated to delay or prevent the development of aging and age-related diseases in recent years. As far as we know, the studies of natural polyphenols in aging and aging-related diseases have never been extensively reviewed. In the present paper, we reviewed recent advances of natural polyphenols in aging and common age-related diseases and the current technological methods to improve the bioavailability of natural polyphenols. The results showed that natural polyphenols have the potential to prevent or treat aging and common age-related diseases through multiple mechanisms. Nanotechnology, structural modifications, and matrix processing could provide strong technical support for the development of natural polyphenols to prevent or treat aging and age-related diseases. In conclusion, natural polyphenols have important potential in the prevention and treatment of aging and age-related diseases.

Blockade of PVN neuromedin B receptor alleviates inflammation via the RAS/ROS/NF-κB pathway in spontaneously hypertensive rats

Neuromedin B (NMB) has potentially great impacts on the development of cardiovascular diseases by promoting hypertensive and sympatho-excitation effects. However, studies regarding the NMB function in paraventricular nucleus (PVN) are lacking. With selective neuromedin B receptor (NMBR) antagonist, BIM-23127, we aim to determine whether the blockade of NMB function in PVN could alleviate central inflammation and attenuate hypertensive responses. Spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY) were chronically infused with BIM-23127 in the PVN for 6 weeks. Mean arterial pressure (MAP) was assessed with tail cuff and electrophysiological acquisition systems. PVN tissues were collected to analyze expressions of Fra-LI, inflammatory cytokines (IL-1β, TNF-α, IL-6, IL-10, and IL-4), renin-angiotensin system (angiotensin-converting enzyme (ACE), ACE2, and AT1-reporter (AT1-R)) and oxidative stress (reactive oxygen species (ROS), superoxide dismutase (SOD)1, NADPH oxidase (NOX)2, and NOX4). ELISA was used to detect inflammation indices, norepinephrine (NE), and nuclear factor κB (NF-κB) p65 in plasma and PVN tissue homogenate. Compared to WKY, SHR exhibited higher mean arterial pressure (MAP), plasma NE, and pro-inflammatory cytokines (PICs). Higher PVN levels of Fra-LI, PICs, ACE, AT1-R, ROS, NOX2, NOX4, and NF-κB p65, while lower central levels of anti-inflammatory cytokines (AICs), ACE2, and SOD1 were observed in SHR. Administration of BIM-23127 in PVN reversed all these changes in SHR. In SHR, blockade of NMBR in the PVN inhibited sympatho-excitation and attenuated hypertensive response. The attenuation mechanism may involve reducing inflammation and the RAS/ROS/ NF-κB pathways in PVN.

A bio-functional cryogel with antioxidant activity for potential application in bone tissue repairing

Antioxidant and free radical resistance has been a key concern of tissue engineering. In this study, Hydroxyapatite (HAp) with osteogenic activity and Oligomeric Proantho Cyanidins (OPC) with antioxidant activity were chemically grafted to prepare gelatin-based biofunctional aerogel (GHPOS). SEM results confirmed that these aerogels exhibited obvious macroporous structure and could provide a suitable microenvironment for bone cell growth. The addition of HAP-PEI-OPC made it have good antioxidant activity, and the cell results proved that the aerogel prepared in this study had good cytocompatibility and did not produce cytotoxicity. The addition of nanoparticles played an important role in the activity of 3T3-E1. The results showed that these bioactive aerogel scaffolds have potential applications in bone tissue engineering.

Nanotechnological advances in cancer: therapy a comprehensive review of carbon nanotube applications

Nanotechnology is revolutionising different areas from manufacturing to therapeutics in the health field. Carbon nanotubes (CNTs), a promising drug candidate in nanomedicine, have attracted attention due to their excellent and unique mechanical, electronic, and physicochemical properties. This emerging nanomaterial has attracted a wide range of scientific interest in the last decade. Carbon nanotubes have many potential applications in cancer therapy, such as imaging, drug delivery, and combination therapy. Carbon nanotubes can be used as carriers for drug delivery systems by carrying anticancer drugs and enabling targeted release to improve therapeutic efficacy and reduce adverse effects on healthy tissues. In addition, carbon nanotubes can be combined with other therapeutic approaches, such as photothermal and photodynamic therapies, to work synergistically to destroy cancer cells. Carbon nanotubes have great potential as promising nanomaterials in the field of nanomedicine, offering new opportunities and properties for future cancer treatments. In this paper, the main focus is on the application of carbon nanotubes in cancer diagnostics, targeted therapies, and toxicity evaluation of carbon nanotubes at the biological level to ensure the safety and real-life and clinical applications of carbon nanotubes.

Preparation of Sweet Potato Porous Starch by Marine Dextranase and Its Adsorption Characteristics

Dextranase (EC 3.2.1.11) is primarily applied in food, sugar, and pharmaceutical industries. This study focuses on using a cold shock Escherichia coli expression system to express marine dextranase SP5-Badex; enzyme activity increased about 2.2-fold compared to previous expression. This enzyme was employed to produce sweet potato porous starch, with special emphasis on the pore size of the starch. The water and oil adsorption rates of the porous starch increased by 1.43 and 1.51 times, respectively. Extensive Fourier transform infrared spectroscopy and X-ray diffraction revealed that the crystal structure of the sweet potato starch was unaltered by enzymatic hydrolysis. The adsorption capacities of the porous starch for curcumin and proanthocyanidins were 9.59 and 12.29 mg/g, respectively. Notably, the stability of proanthocyanidins was significantly enhanced through their encapsulation in porous starch. After 2.5 h of ultraviolet irradiation, the free radical scavenging rate of the encapsulated proanthocyanidins remained at 95.10%. Additionally, after 30 days of sunlight exposure, the free radical scavenging rate of the encapsulated proanthocyanidins (84.42%) was significantly higher than that (24.34%) observed in the control group. These research findings provide substantial experimental evidence for preparing sweet potato porous starch using marine dextranase.

ROS/pH dual responsive PRP-loaded multifunctional chitosan hydrogels with controlled release of growth factors for skin wound healing

Platelet-rich plasma (PRP) contains a variety of growth factors (GFs) and has been used in the treatment of a variety of diseases, including skin lesions. In particular, PRP with low immunogenicity will be more widely used. However, the explosive release of GFs limits its further application. In order to achieve controlled release of GFs, a multifunctional and reactive oxygen species (ROS)/pH dual responsive hydrogel was developed to load PRP derived from human cord blood for the treatment of skin wound healing. Based on the hydrogen bond and Schiff base interaction, carboxymethyl chitosan (CMCS), oxidized dextran (Odex) and oligomeric procyanidins (OPC) were crosslinked to form CMCS/Odex/OPC/PRP hydrogel with good injectability, self-healing, adhesion, ROS scavenging, antibacterial activity, controlled and sustained release of GFs. In vitro cell experiments suggested that this hydrogel possessed excellent biocompatibility and could promote the proliferation and migration of L929. In vivo healing of full-layer skin wounds further indicated that the prepared hydrogel could regulate inflammation and promote epithelialization, collagen deposition, and angiogenesis. In summary, this present study demonstrates that CMCS/Odex/OPC/PRP hydrogel may serve as a promising multifunctional dressing for skin wound healing.

Capsaicin improves hypertension and cardiac hypertrophy via SIRT1/NF-κB/MAPKs pathway in the hypothalamic paraventricular nucleus

BACKGROUND

Hypertension has seriously affected a large part of the adult and elderly population. The complications caused by hypertension are important risk factors for cardiovascular disease accidents. Capsaicin, a pungent component of chili pepper has been revealed to improve hypertension. However, its potential mechanism in improving hypertension remains to be explored.

PURPOSE

In the present study, we aimed to investigate whether capsaicin could attenuate the SIRT1/NF-κB/MAPKs pathway in the paraventricular nucleus of hypothalamus (PVN).

METHODS

We used spontaneous hypertensive rats (SHRs) as animal model rats. Micro osmotic pump was used to give capsaicin through PVN for 28 days, starting from age12-week-old.

RESULTS

The results showed that capsaicin significantly reduced blood pressure from the 16th day of infusion onward. At the end of the experimental period, we measured cardiac hypertrophy index and the heart rate (HR), and the results showed that the cardiac hypertrophy and heart rate of rats was significantly improved upon capsaicin chronic infusion. Norepinephrine (NE) and epinephrine (EPI) in plasma of SHRs treated with capsaicin were also decreased. Additionally, capsaicin increased the protein expression and number of positive cells of SIRT1 and the 67-kDa isoform of glutamate decarboxylase (GAD67), decreased the production of reactive oxygen species (ROS), number of positive cells of NOX2, those of Angiotensin Converting Enzyme (ACE) and p-IKKβ, tyrosine hydroxylase (TH), the gene expression levels of NOX4 and pro-inflammatory cytokines. Capsaicin also decreased the relative protein expressions of protein in MAPKs pathway.

CONCLUSION

Current data indicated that capsaicin within the PVN improves hypertension and cardiac hypertrophy via SIRT1/NF-κB/MAPKs pathway in the PVN of SHRs, supporting its potential as candidate drug for preventing and improving hypertension.

Proanthocyanidins may be potential therapeutic agents for the treatment of carotid atherosclerosis: A review

Atherosclerotic cerebrovascular disease is one of the major causes of death in China, with associated serious risk of disability and burden on society and families. Therefore, the development of active and effective therapeutic drugs for this disease is of great significance. Proanthocyanidins are a class of naturally occurring active substances, rich in hydroxyl groups and from a wide range of sources. Studies have suggested that they have a strong potential for anti-atherosclerosis activity. In this paper, we review published evidence regarding anti-atherosclerotic effects of proanthocyanidins in different atherosclerotic research models.

Minocycline and Pyrrolidine Dithiocarbamate Attenuate Hypertension via Suppressing Activation of Microglia in the Hypothalamic Paraventricular Nucleus

Proinflammatory cytokines, reactive oxygen species and imbalance of neurotransmitters are involved in the pathophysiology of angiotensin II-induced hypertension. The hypothalamic paraventricular nucleus (PVN) plays a vital role in hypertension. Evidences show that microglia are activated and release proinflammatory cytokines in angiocardiopathy. We hypothesized that angiotensin II induces PVN microglial activation, and the activated PVN microglia release proinflammatory cytokines and cause oxidative stress through nuclear factor-kappa B (NF-κB) pathway, which contributes to sympathetic overactivity and hypertension. Male Sprague-Dawley rats (weight 275-300 g) were infused with angiotensin II to induce hypertension. Then, rats were treated with bilateral PVN infusion of microglial activation inhibitor minocycline, NF-κB activation inhibitor pyrrolidine dithiocarbamate or vehicle for 4 weeks. When compared to control groups, angiotensin II-induced hypertensive rats had higher mean arterial pressure, PVN proinflammatory cytokines, and imbalance of neurotransmitters, accompanied with PVN activated microglia. These rats also had more PVN gp91phox (source of reactive oxygen species production), and NF-κB p65. Bilateral PVN infusion of minocycline or pyrrolidine dithiocarbamate partly or completely ameliorated these changes. This study indicates that angiotensin II-induced hypertensive rats have more activated microglia in PVN, and activated PVN microglia release proinflammatory cytokines and result in oxidative stress, which contributes to sympathoexcitation and hypertensive response. Suppression of activated PVN microglia by minocycline or pyrrolidine dithiocarbamate attenuates inflammation and oxidative stress, and improves angiotensin II-induced hypertension, which indicates that activated microglia promote hypertension through activated NF-κB. The findings may offer hypertension new strategies.

Luteolin Attenuates Hypertension via Inhibiting NF-κB-Mediated Inflammation and PI3K/Akt Signaling Pathway in the Hypothalamic Paraventricular Nucleus

BACKGROUND

Luteolin is widely distributed among a number of vegetal species worldwide. The pharmacological effects of luteolin are diverse and amongst antioxidant, free radical scavenging, and anti-inflammatory activities. Preliminary study showed that luteolin can ameliorate hypertension. However, the precise mechanism needs further investigation. There is no evidence that luteolin affects the paraventricular nucleus of the hypothalamus (PVN), a brain nucleus associated with a critical neural regulator of blood pressure. Our main aim was to explore the effect of luteolin on the PI3K/Akt/NF-κB signaling pathway within the PVN of hypertensive rats.

METHODS

spontaneously hypertensive rats (SHRs) and corresponding normotensive control rats, the Wistar Kyoto (WKY) rats were divided into four groups and subsequently treated for 4 weeks with bilateral PVN injections of either luteolin (20 µg/0.11 µL, volume: 0.11 µL/h) or vehicle (artificial cerebrospinal fluid).

RESULTS

luteolin infusion to the PVN significantly decreased some hemodynamic parameters including the mean arterial pressure (MAP), heart rate (HR), circulating plasma norepinephrine (NE) and epinephrine (EPI). Additionally, there was a decrease in the expressions of the phosphatidylinositol 3-kinase (p-PI3K) and phosphorylated protein kinase-B (p-AKT), levels of reactive oxygen species (ROS), NAD(P)H oxidase subunit (NOX2, NOX4) in the PVN of SHRs. Meanwhile, the expression of inflammatory cytokines and the activity of nuclear factor κB (NF-κB) p65 in the PVN of SHRs were lowered. Furthermore, immunofluorescence results showed that injection of luteolin in the PVN reduced the expression of tyrosine hydroxylase (TH), and increased that of superoxide dismutase (SOD1) and the 67-kDa isoform of glutamate decarboxylase (GAD67) in the PVN of SHRs.

CONCLUSION

Our novel findings revealed that luteolin lowered hypertension via inhibiting NF-κB-mediated inflammation and PI3K/Akt signaling pathway in the PVN.

Role of blood-borne factors in sympathoexcitation-mediated hypertension: Potential neurally mediated hypertension in preeclampsia

Hypertension remains a threat for society due to its unknown causes, preventing proper management, for the growing number of patients, for its state as a high-risk factor for stroke, cardiac and renal complication and as cause of disability. Data from clinical and animal researches have suggested the important role of many soluble factors in the pathophysiology of hypertension through their neuro-stimulating effects. Central targets of these factors are of molecular, cellular and structural nature. Preeclampsia (PE) is characterized by high level of soluble factors with strong pro-hypertensive activity and includes immune factors such as proinflammatory cytokines (PICs). The potential neural effect of those factors in PE is still poorly understood. Shedding light into the potential central effect of the soluble factors in PE may advance our current comprehension of the pathophysiology of hypertension in PE, which will contribute to better management of the disease. In this paper, we summarized existing data in respect of hypothesis of this review, that is, the existence of the neural component in the pathophysiology of the hypertension in PE. Future studies would address this hypothesis to broaden our understanding of the pathophysiology of hypertension in PE.

Genistein Alleviates Oxidative Stress and Inflammation in the Hypothalamic Paraventricular Nucleus by Activating the Sirt1/Nrf2 Pathway in High Salt-Induced Hypertension

Hypertension caused by a high-salt (HS) diet is one of the major causes of cardiovascular diseases. Underlining pathology includes oxidative stress and inflammation in the hypothalamic paraventricular nucleus (PVN). This study investigates genistein's (Gen) role in HS-induced hypertension and the underlying molecular mechanism. We placed male Wistar rats on HS (8% NaCl) or normal salt diet (0.3% NaCl). Then, we injected bilateral PVN in rats with Gen, vehicle, or nicotinamide (NAM) for 4 weeks. Tail cuff was used weekly to assess the systolic pressure, diastolic pressure, and mean arterial pressure (MAP). Cardiac hypertrophy was analyzed by heart weight/body weight ratio and wheat germ agglutinin staining. ELISA kits, Western blot, or dihydroethidium staining determined the levels of inflammatory cytokines and oxidative stress markers. Western blot measured protein levels of Sirt1, Ac-FOXO1, Nrf2, NQO-1, HO-1, and gp91^phox. Our result showed that PVN infusion of Gen significantly reduced the increase of systolic pressure, diastolic pressure, and MAP induced by an HS diet. Additionally, there was a decrease in cardiac hypertrophy and the levels of inflammatory cytokines in PVN and plasma. Meanwhile, PVN infusion of Gen notably inhibited the levels of oxidized glutathione and superoxide dismutase and improved the glutathione level and total antioxidant capacities and superoxide dismutase activities. It also decreased the level of reactive oxygen species and gp91^phox expression in PVN. Furthermore, Gen infusion markedly increases the Sirt1, Nrf2, HO-1, and NQO-1 levels and decreases the Ac-FOXO1 level. However, PVN infusion of NAM could significantly block these changes induced by Gen in HS diet rats. Our results demonstrated that PVN infusion of Gen could inhibit the progression of hypertension induced by an HS diet by activating the Sirt1/Nrf2 pathway.

Exercise Training Attenuates Hypertension via Suppressing ROS/MAPK/NF-κB/AT-1R Pathway in the Hypothalamic Paraventricular Nucleus

Background: Aerobic exercise training (ExT) is beneficial for hypertension, however, its central mechanisms in improving hypertension remain unclear. Since the importance of the up-regulation of angiotensin II type 1 receptor (AT-1R) in the paraventricular nucleus (PVN) of the hypothalamic in sympathoexcitation and hypertension has been shown, we testified the hypothesis that aerobic ExT decreases blood pressure in hypertensive rats by down-regulating the AT-1R through reactive oxygen species (ROS)/mitogen-activated protein kinase (MAPK)/nuclear factors κB (NF-κB) pathway within the PVN. Methods: Forty-eight male Sprague-Dawley (SD) rats were assigned to the following groups: sham operation (SHAM) + kept sedentary (Sed), SHAM + exercise training (ExT), two kidney-one clamp (2K1C) + Sed, and 2K1C + ExT groups. Results: The 2K1C + Sed hypertensive rats showed higher systolic blood pressure (SBP), upregulated ROS, phosphorylated (p-) p44/42 MAPK, p-p38 MAPK, NF-κB p65 activity, and AT-1R expression in the PVN, and increased circulating norepinephrine (NE) than those of SHAM rats. After eight weeks of aerobic ExT, the 2K1C + ExT hypertensive rats showed attenuated NE and SBP levels, suppressed NF-κB p65 activity, and reduced expression of ROS, p-p44/42 MAPK, p-p38 MAPK, and AT-1R in the PVN, relatively to the 2K1C + Sed group. Conclusions: These data are suggestive of beneficial effects of aerobic ExT in decreasing SBP in hypertensive rats, via down-regulating the ROS/MAPK/NF-κB pathway that targets AT-1R in the PVN, and eventually ameliorating 2K1C-induced hypertension.

Blockade of Microglial Activation in Hypothalamic Paraventricular Nucleus Improves High Salt-Induced Hypertension

BACKGROUND

It has been shown that activated microglia in brain releasing proinflammatory cytokines (PICs) contribute to the progression of cardiovascular diseases. In this study, we tested the hypothesis that microglial activation in hypothalamic paraventricular nucleus (PVN), induced by high-salt diet, increases the oxidative stress via releasing PICs and promotes sympathoexcitation and development of hypertension.

METHODS

High-salt diet was given to male Dahl salt-sensitive rats to induce hypertension. Those rats were bilaterally implanted with cannula for PVN infusion of minocycline, a selective microglial activation blocker, or artificial cerebrospinal fluid for 4 weeks.

RESULTS

High-salt diet elevated mean arterial pressure of Dahl salt-sensitive rats. Meanwhile, elevations of renal sympathetic nerve activity and central prostaglandin E2, as well as increase of plasma norepinephrine, were observed in those hypertensive rats. Tumor necrosis factor-α, interleukin-1β (IL-1β), and IL-6 increased in the PVN of those rats, associated with a significant activation of microglia and prominent disruption of redox balance, which was demonstrated by higher superoxide and NAD(P)H oxidase 2 (NOX-2) and NAD(P)H oxidase 4 (NOX-4), and lower Cu/Zn superoxide dismutase in PVN. PVN infusion of minocycline attenuated all hypertension-related alterations described above.

CONCLUSION

This study indicates that high salt leads to microglial activation within PVN of hypertensive rats, and those activated PVN microglia release PICs and trigger the production of reactive oxygen species, which contributes to sympathoexcitation and development of hypertension. Blockade of PVN microglial activation inhibits inflammation and oxidative stress, therefore attenuating the development of hypertension induced by high-salt diet.

Effects of Nrf1 in Hypothalamic Paraventricular Nucleus on Regulating the Blood Pressure During Hypertension

The incidence rate and mortality of hypertension increase every year. Hypothalamic paraventricular nucleus (PVN) plays a critical role on the pathophysiology of hypertension. It has been demonstrated that the imbalance of neurotransmitters including norepinephrine (NE), glutamate (Glu) and γ-aminobutyric acid (GABA) are closely related to sympathetic overactivity and pathogenesis of hypertension. N-methyl-D-aspartate receptor (NMDAR), consisting of GluN1 and GluN2 subunits, is considered to be a glutamate-gated ion channel, which binds to Glu, and activates neuronal activity. Studies have found that the synthesis of respiratory chain enzyme complex was affected and mitochondrial function was impaired in spontaneously hypertensive rats (SHR), further indicating that mitochondria is associated with hypertension. Nuclear respiratory factor 1 (Nrf1) is a transcription factor that modulates mitochondrial respiratory chain and is related to GluN1, GluN2A, and GluN2B promoters. However, the brain mechanisms underlying PVN Nrf1 modulating sympathoexcitation and blood pressure during the development of hypertension remains unclear. In this study, an adeno-associated virus (AAV) vector carrying the shRNA targeting rat Nrf1 gene (shNrf1) was injected into bilateral PVN of male rats underwent two kidneys and one clip to explore the role of Nrf1 in mediating the development of hypertension and sympathoexcitation. Administration of shNrf1 knocked down the expression of Nrf1 and reduced the expression of excitatory neurotransmitters, increased the expression of inhibitory neurotransmitters, and reduced the production of reactive oxygen species (ROS), and attenuated sympathoexcitation and hypertension. The results indicate that knocking down Nrf1 suppresses sympathoexcitation in hypertension by reducing PVN transcription of NMDAR subunits (GluN1, GluN2A, and GluN2B), rebalancing PVN excitatory and inhibitory neurotransmitters, inhibiting PVN neuronal activity and oxidative stress, and attenuating sympathetic activity.