Evidence-Based Anti-Diabetic Properties of Plant from the Occitan Valleys of the Piedmont Alps.

Data on urban and rural diabetes prevalence ratios show a significantly lower presence of diabetes in rural areas. Several bioactive compounds of plant origin are known to exert anti-diabetic properties. Interestingly, most of them naturally occur in different plants present in mountainous areas and are linked to traditions of herbal use. This review will aim to evaluate the last 10 years of evidence-based data on the potential anti-diabetic properties of 9 plants used in the Piedmont Alps (North-Western Italy) and identified through an ethnobotanical approach, based on the Occitan language minority of the Cuneo province (Sambucus nigra L., Achillea millefolium L., Cornus mas L., Vaccinium myrtillus L., Fragaria vesca L., Rosa canina L., Rubus idaeus L., Rubus fruticosus/ulmifolius L., Urtica dioica L.), where there is a long history of herbal remedies. The mechanism underlying the anti-hyperglycemic effects and the clinical evidence available are discussed. Overall, this review points to the possible use of these plants as preventive or add-on therapy in treating diabetes. However, studies of a single variety grown in the geographical area, with strict standardization and titration of all the active ingredients, are warranted before applying the WHO strategy 2014-2023.

CNS-Sparing Histamine H3 Receptor Antagonist as a Candidate to Prevent the Diabetes-Associated Gastrointestinal Symptoms.

Among the histamine receptors, growing evidence points to the histamine H3 receptor as a pharmacological candidate to counteract the autonomic neuropathy associated with diabetes. The study aimed to evaluate the effect of PF00868087 (also known as ZPL-868), a CNS-sparing histamine H3 receptor antagonist, on the autonomic neuropathy of the intestinal tract associated with diabetes. Diabetes was induced in male BALB/c mice by a single high dose of streptozotocin (150 mg/kg). Colorectal specimens from control and diabetic mice, randomized to vehicle or PF0086087 (10, 30, 100 mg/kg/day by oral gavage for 14 days), were processed for morphological and immunohistochemical analysis. A significant overproduction of mucus in the intestinal mucosa of diabetic mice compared to the controls was observed. PF0086087 at the highest dose prevented mucin overproduction. The immunohistochemistry analysis demonstrated that diabetes causes a decrease in the inhibitory component of enteric motility, measured as the percentage of neuronal nitric oxide synthase-positive neurons (p < 0.05) and a parallel increase in the excitatory component evaluated as substance P-positive fibres (p < 0.01). PF0086087 dose-dependently prevented these pathophysiological events. In conclusion, PF0086087 may be an essential tool in preventing nitrergic dysfunction in the myenteric plexus of the distal colon and diabetes-induced gastrointestinal complications.

The Interplay between Histamine H4 Receptor and the Kidney Function: The Lesson from H4 Receptor Knockout Mice.

Previous studies implicated the histamine H4 receptor in renal pathophysiology. The aim here is to elucidate the role of this receptor on renal function using H4 receptor knockout mice (H4R-/-). Healthy and diabetic H4R-/- mice compared to their C57BL/6J wild-type counterpart for renal function and the expression of crucial tubular proteins. H4R-/- and wild-type mice, matched for ages, showed comparable weight gain curves reaching similar median weight at the end of the study. However, H4R-/- mice displayed a higher basal glycemia. H4R-/- mice showed a lower urine 24 h outflow, and albumin-to-creatinine ratio (ACR) compared to wild-type mice. Consistently, H4R-/- mice presented a higher expression of megalin and a lower basal expression of the sodium-hydrogen exchanger (NHE)3 and aquaporin (AQP)2. According to these basal differences, diabetic H4R-/- mice developed more severe hyperglycemia and a higher 24 h urine volume, but a lower increase in ACR and decrease in urine pH were observed. These events were paralleled by a reduced NHE3 over-expression and megalin loss in diabetic H4R-/- mice. The AQP1 and AQP7 patterns were also different between H4R-/- and wild-type diabetic mice. The collected results highlight the role of the histamine H4 receptor in the control of renal reabsorption processes, particularly albumin uptake.

Superoxide Dismutase Administration: A Review of Proposed Human Uses.

Superoxide dismutases (SODs) are metalloenzymes that play a major role in antioxidant defense against oxidative stress in the body. SOD supplementation may therefore trigger the endogenous antioxidant machinery for the neutralization of free-radical excess and be used in a variety of pathological settings. This paper aimed to provide an extensive review of the possible uses of SODs in a range of pathological settings, as well as describe the current pitfalls and the delivery strategies that are in development to solve bioavailability issues. We carried out a PubMed query, using the keywords "SOD", "SOD mimetics", "SOD supplementation", which included papers published in the English language, between 2012 and 2020, on the potential therapeutic applications of SODs, including detoxification strategies. As highlighted in this paper, it can be argued that the generic antioxidant effects of SODs are beneficial under all tested conditions, from ocular and cardiovascular diseases to neurodegenerative disorders and metabolic diseases, including diabetes and its complications and obesity. However, it must be underlined that clinical evidence for its efficacy is limited and consequently, this efficacy is currently far from being demonstrated.

Strategies to expand the therapeutic potential of superoxide dismutase by exploiting delivery approaches.

The overproduction of free radicals can cause oxidative-stress damage to a range of biomolecules, and thus potentially contribute to several pathologies, from neurodegenerative disorders to cardiovascular diseases and metabolic disorders. Endogenous antioxidant enzymes, such as superoxide dismutase (SOD), play an important role in diminishing oxidative stress. SOD supplementation could therefore be an effective preventive strategy to reduce the risk of free-radical overproduction. However, the efficacy of SOD administration is hampered by its rapid clearance. Several different approaches to improve the bioavailability of SOD have been explored in recent decades. This review intends to describe the rationale that underlie the various approaches and chemical strategies that have led to the most recent advances in SOD delivery. This critical description includes SOD conjugates, SOD loaded into particulate carriers (micelles, liposomes, nanoparticles, microparticles) and the most promising and suitable formulations for oral delivery, with a particular emphasis on reports of preclinical/clinical results. Likely future directions are also considered and reported.

Effect of Beta 3 Adrenoreceptor Modulation on Patency of the Ductus Arteriosus.

ß3-adrenoreceptor (ß3-AR), a G-protein coupled receptor, has peculiar regulatory properties in response to oxygen and widespread localization. ß3-AR is expressed in the most frequent neoplasms, also occurring in pregnant women, and its blockade reduces tumor growth, indicating ß3-AR-blockers as a promising alternative to antineoplastic drugs during pregnancy. However, ß3-AR involvement in prenatal morphogenesis and the consequences of its blockade for the fetus remain unknown. In this study, after the demonstrated expression of ß3-AR in endothelial and smooth muscle cells of ductus arteriosus (DA), C57BL/6 pregnant mice were acutely treated at 18.5 of gestational day (GD) with indomethacin or with the selective ß3-AR antagonist SR59230A, or chronically exposed to SR59230A from 15.5 to 18.5 GD. Six hours after the last treatment, fetuses were collected. Furthermore, newborn mice were treated straight after birth with BRL37344, a ß3-AR agonist, and sacrificed after 7 h. SR59230A, at the doses demonstrated effective in reducing cancer progression (10 and 20 mg/kg) in acute and chronic mode, did not induce fetal DA constriction and did not impair the DA ability to close after birth, whereas at the highest dose (40 mg/kg), it was shown to cause DA constriction and preterm-delivery. BRL37344 administered immediately after birth did not alter the physiological DA closure.

Nanosponges as protein delivery systems: Insulin, a case study.

Cyclodextrin-based nanosponges have been found to bepromising drug delivery systems. This paper investigates an application that still needs to be studied in depth, that is, the oral delivery of peptides and proteins, choosing insulin as a case study. The nanospongewas synthesized by crosslinkingß-cyclodextrins withpyromellitic dianhydride, adopting a top-down approach for its subsequent formulation. Aphysicochemical characterization, in-vitro andin-vivo tests were carried out on the formulation developed. It was nanometric (around 250 nm) with high negative zeta potential, mucoadhesion and swelling properties, good loading capability (about 14%) and encapsulation efficiency (above 90%). The in-vitro release of insulin was negligible at a gastric pH (below 2%) while sustained at an intestinal pH, thus showing a pH-sensitive behaviour of the nanosponge. The Caco-2 cell permeability assay proved that the intestinal permeation of insulin was enhanced when loaded inside the nanosponge. The in-vivo studies confirmed the presence of insulin in rat plasma and a marked hypoglycemic effect in diabetic mice after duodenal and oral administrations, respectively. These preliminary results are encouraging with a view to continuing to study this ß-cyclodextrin nanosponge technology for the oral administration of insulin and extending this approach to other proteins of pharmaceutical interest.

Histamine in the kidneys: what is its role in renal pathophysiology?

Starting with a role for histamine role in renal haemodynamics, evidence has accumulated, over time, suggesting a wider range of actions on renal function and this has renewed interest in the pathophysiological role of histamine in the kidney. Here we provide an up-to-date review of this topic. As the kidney expresses enzymes that synthesize and metabolise histamine, along with its receptors, all the components for histaminergic transmission are present in this tissue. The distribution of histamine receptors matches a wide range of effects. We address the questions of the redundancy of H1 and H2 receptors in renal haemodynamics, the complementary role of H1 and H4 receptors in renal filtration and reabsorption, and the dichotomy between local and neuronal H1 and H3 receptors. Experimental models of renal disease raise the possibility of new therapeutic approaches based on histamine. The effects of histamine on renal function are not yet fully understood and their elucidation is still ongoing. LINKED ARTICLES: This article is part of a themed section on New Uses for 21st Century. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.3/issuetoc.

Post-translational inhibition of YAP oncogene expression by 4-hydroxynonenal in bladder cancer cells.

The transcriptional regulator YAP plays an important role in cancer progression and is negatively controlled by the Hippo pathway. YAP is frequently overexpressed in human cancers, including bladder cancer. Interestingly, YAP expression and activity can be inhibited by pro-oxidant conditions; moreover, YAP itself can also affect the cellular redox status through multiple mechanisms. 4-Hydroxynonenal (HNE), the most intensively studied end product of lipid peroxidation, is a pro-oxidant agent able to deplete GSH and has an anti-tumoral effect by affecting multiple signal pathways, including the down-regulation of oncogene expressions. These observations prompted us to investigate the effect of HNE on YAP expression and activity. We demonstrated that HNE inhibited YAP expression and its target genes in bladder cancer cells through a redox-dependent mechanism. Moreover, the YAP down-regulation was accompanied by an inhibition of proliferation, migration, invasion, and angiogenesis, as well as by an accumulation of cells in the G2/M phase of cell cycle and by an induction of apoptosis. We also established the YAP role in inhibiting cell viability and inducing apoptosis in HNE-treated cells by using an expression vector for YAP. Furthermore, we identified a post-translational mechanism for the HNE-induced YAP expression inhibition, involving an increase of YAP phosphorylation and ubiquitination, leading to proteasomal degradation. Our data established that HNE can post-translationally down-regulate YAP through a redox-dependent mechanism and that this modulation can contribute to determining the specific anti-cancer effects of HNE.

Effect of Bilastine on Diabetic Nephropathy in DBA2/J Mice.

Diabetic nephropathy is an unmet therapeutic need, and the search for new therapeutic strategies is warranted. Previous data point to histamine H1 receptor as a possible target for glomerular dysfunction associated with long term hyperglycaemia. Therefore, this study investigated the effects of the H1 receptor antagonist bilastine on renal morphology and function in a murine model of streptozotocin-induced diabetes. Diabetes was induced in DBA2/J male mice and, from diabetes onset (glycaemia ≥200 mg/dL), mice received bilastine (1-30 mg/kg/day) by oral gavage for 14 consecutive weeks. At the end of the experimental protocol, diabetic mice showed polyuria (+195.5%), increase in Albumin-to-Creatine Ratio (ACR, +284.7%), and a significant drop in creatinine clearance (p < 0.05). Bilastine prevented ACR increase and restored creatinine clearance in a dose-dependent manner, suggesting a positive effect on glomerular filtration. The ultrastructural analysis showed a preserved junctional integrity. Preservation of the basal nephrin, P-cadherin, and synaptopodin expression could explain this effect. In conclusion, the H1 receptor could contribute to the glomerular damage occurring in diabetic nephropathy. Bilastine preserved the glomerular junctional integrity, leading to the hypothesis of anti-H1 antihistamines as a possible add-on therapy for diabetic nephropathy.

Histamine and diabetic nephropathy: an up-to-date overview.

The classification of diabetic nephropathy (DN) as a vascular complication of diabetes makes the possible involvement of histamine, an endogenous amine that is well known for its vasoactive properties, an interesting topic for study. The aim of the present review is to provide an extensive overview of the possible involvement of histamine in the onset and progression of DN. The evidence collected on the role of histamine in kidney function together with its well-known pleiotropic action suggest that this amine may act simultaneously on glomerular hyperfiltration, tubular inflammation, fibrosis development and tubular hypertrophy.

Analyzing Cysteine Site Neighbors in Proteins to Reveal Dimethyl Fumarate Targets.

This work proposes a novel approach by which to consistently classify cysteine sites in proteins in terms of their reactivity toward dimethyl fumarate (DMF) and fumarate. Dimethyl fumarate-based drug products have been approved for use as oral treatments for psoriasis and relapsing-remitting multiple sclerosis. The adduction of DMF and its (re)active metabolites to certain cysteine residues in proteins is thought to underlie their effects. However, only a few receptors for these compounds have been discovered to date. Our approach takes advantage of the growing number of known DMF- and fumarate-sensitive proteins and sites to perform analyses by combining the concepts of network theory, for protein structure analyses, and machine-learning procedures. Wide-ranging and previously unforeseen variety is found in the analysis of the neighborhood composition (the first neighbors) of cysteine sites found in DMF- and fumarate-sensitive proteins. Furthermore, neighborhood composition has shown itself to be a network-type attribute that is endowed with remarkable predictive power when distinct classification algorithms are employed. In conclusion, when adopted in combination with other target identification/validation approaches, methods that are based on the analysis of cysteine site neighbors in proteins should provide useful information by which to decipher the mode of action of DMF-based drugs.

Histamine H4 receptor antagonism prevents the progression of diabetic nephropathy in male DBA2/J mice.

Due to the incidence of diabetes and the related morbidity of diabetic nephropathy, identification of new therapeutic strategies represents a priority. In the last few decades new and growing evidence on the possible role of histamine in diabetes has been provided. In particular, the histamine receptor H4R is emerging as a new promising pharmacological target for diabetic nephropathy. The aim of this study was to evaluate the efficacy of selective H4R antagonism by JNJ39758979 on the prevention of diabetic nephropathy progression in a murine model of diabetes induced by streptozotocin injection. JNJ39758979 (25, 50, 100 mg/kg/day p.o.) was administered for 15 weeks starting from the onset of diabetes. Functional parameters were monitored throughout the experimental period. JNJ39758979 did not significantly affect glycaemic status or body weight. The urine analysis indicated a dose-dependent inhibitory effect of JNJ39758979 on Albumin-Creatinine-Ratio, the Creatinine Clearance, the 24 h urine volume, and pH urine acidification (P < 0.05). The beneficial effects of JNJ39758979 on renal function paralleled comparable effects on renal morphological integrity. These effects were sustained by a significant immune infiltration and fibrosis reduction. Notably, megalin and sodium-hydrogen-exchanger 3 expression levels were preserved. Our data suggest that the H4R participates in diabetic nephropathy progression through both a direct effect on tubular reabsorption and an indirect action on renal tissue architecture via inflammatory cell recruitment. Therefore, H4R antagonism emerges as a possible new multi-mechanism therapeutic approach to counteract development of diabetic nephropathy development.

Solid lipid nanoparticles delivering anti-inflammatory drugs to treat inflammatory bowel disease: Effects in an in vivo model.

AIM: To improve anti-inflammatory activity while reducing drug doses, we developed a nanoformulation carrying dexamethasone and butyrate. METHODS: Dexamethasone cholesteryl butyrate-solid lipid nanoparticles (DxCb-SLN) were obtained with the warm microemulsion method. The anti-inflammatory activity of this novel nanoformulation has been investigated in vitro (cell adhesion to human vascular endothelial cells and pro-inflammatory cytokine release by lipopolysaccharide-induced polymorphonuclear cells) and in vivo (disease activity index and cytokine plasma concentrations in a dextran sulfate sodium-induced mouse colitis) models. Each drug was also administered separately to compare its effects with those induced by their co-administration in SLN at the same concentrations. RESULTS: DxCb-SLN at the lowest concentration tested (Dx 2.5 nmol/L and Cb 0.1 µmol/L) were able to exert a more than additive effect compared to the sum of the individual effects of each drug, inducing a significant in vitro inhibition of cell adhesion and a significant decrease of pro-inflammatory cytokine (IL-1ß and TNF-α) in both in vitro and in vivo models. Notably, only the DxCb nanoformulation administration was able to achieve a significant cytokine decrease compared to the cytokine plasma concentration of the untreated mice with dextran sulfate sodium-induced colitis. Specifically, DxCb-SLN induced a IL-1ß plasma concentration of 61.77% ± 3.19%, whereas Dx or Cb used separately induced a concentration of 90.0% ± 2.8% and 91.40% ± 7.5%, respectively; DxCb-SLN induced a TNF-α plasma concentration of 30.8% ± 8.9%, whereas Dx or Cb used separately induced ones of 99.5% ± 4.9% and 71.1% ± 10.9%, respectively. CONCLUSION: Our results indicate that the co-administration of dexamethasone and butyrate by nanoparticles may be beneficial for inflammatory bowel disease treatment.

Histamine type 1-receptor activation by low dose of histamine undermines human glomerular slit diaphragm integrity.

Histamine has been reported to decrease the ultrafiltration coefficient, which inversely correlates with glomerular permselectivity, however the mechanism(s) underling this effect have never been investigated. This study aimed to assess whether histamine could exert a direct detrimental effect on podocyte permeability and the possible involvement of two key proteins for the glomerular slit diaphragm (SD) integrity, zonula occludens-1 (ZO-1) and P-cadherin. The effect of histamine (100 pM-1000nM) on coloured podocytes junctional integrity was evaluated functionally by a transwell assay of monolayer permeability and morphologically by electron microscopy. Histamine receptor (H1-4R) presence was evaluated at both mRNA (RT-PCR) and protein (immunofluorescence) levels. The Kd and Bmax values for [3H]mepyramine were determined by saturation binding analysis; IP1 and cAMP production evoked by histamine were measured by TR-FRET. ZO-1, P-cadherin and vimentin expression was assessed by qRT-PCR and quantitative immunoblotting. Histamine elicited a time- and sigmoidal dose-dependent (maximum effect at 8h, 10nM) increase in podocyte paracellular permeability widening the paracellular spaces. Only H1R was predominantly localised to the podocyte membrane. Consistently, histamine elicited a sigmoidal dose-dependent increase in IP1, but not in cAMP. Histamine exposure evoked a concentration-dependent reduction in both ZO-1 and P-cadherin and a parallel induction of vimentin mRNA expression with a maximum effect after 6h, and protein expression with a maximum effect after 8h. These effects were prevented by the selective H1R antagonist chlorpheniramine. In conclusion, our data demonstrate that histamine, via the H1R, modifies SD morphological and functional integrity, in part, by decreasing the expression of ZO-1 and P-cadherin.

Role of histamine H4 receptor ligands in bleomycin-induced pulmonary fibrosis.

Fibrosis of lung tissue is a disease where a chronic inflammatory process determines a pathological remodelling of lung parenchyma. The animal model obtained by intra-tracheal administration of bleomycin in C57BL/6 mice is one of the most validated murine model. Bleomycin stimulates oxidative stress and the production of pro-inflammatory mediators. Histamine H4R have recently been implicated in inflammation and immune diseases. This study was focused to investigate the effects of H4R ligands in the modulation of inflammation and in the reduction of lung fibrosis in C57BL/6 mice treated with bleomycin. C57BL/6 mice were treated with vehicle, JNJ7777120 (JNJ, selective H4R antagonist) or ST-1006 (partial H4R agonist), ST-994 (H4R neutral antagonist) and ST-1012 (inverse H4R agonist) at equimolar doses, released by micro-osmotic pumps for 21days. Airway resistance to inflation was assayed and lung samples were processed to measure malondialdehyde (TBARS); 8-hydroxy-2'-deoxyguanosine (8OHdG); myeloperoxidase (MPO); COX-2 expression and activity as markers of oxidative stress and inflammation. Fibrosis and airway remodelling were evaluated throughout transforming growth factor-ß (TGF-ß), percentage of positive Goblet cells, smooth muscle layer thickness determination. Our results indicated that JNJ, ST-994 and ST-1012 decreased inflammation and oxidative stress markers, i.e. the number of infiltrating leukocytes evaluated as lung tissue MPO, COX-2 expression and activity, TBARS and 8OHdG production. They also reduced the level of TGF-ß, a pro-fibrotic cytokine, collagen deposition, thickness of smooth muscle layer, Goblet cells hyperplasia; resulting in a decrease of airway functional impairment. The results here reported clearly demonstrated that H4R ligands have a beneficial effect in a model of lung fibrosis in the mouse, thus indicating that H4R antagonists or inverse agonists could be a novel therapeutic strategy for lung inflammatory diseases.

Histamine in diabetes: Is it time to reconsider?

The first studies of histamine and diabetes date back to the 1950s. Since that time the involvement of histamine in diabetes was related to its well known vasoactive properties and permeability leakage effects. In particular, the first evidence for a correlation between histamine and diabetes arose in 1989 when an increase in plasma and leucocyte histamine content was observed. Limited independent evidence followed in the subsequent two decades, focusing on both histamine glyceamic control and macro- and microvascular complications of diabetes. However, recent observations have sparked the question whether it is time to reconsider the functional contribution of histamine in diabetes. We reveal an interesting upsurge in the field which provides scope for new insights into the role of histamine in diabetes.

Histamine receptor expression in human renal tubules: a comparative pharmacological evaluation.

OBJECTIVE AND DESIGN: The aim of this study is to evaluate the expression of the histamine receptors, particularly focusing on the H4R in human renal tubules. MATERIAL: The ex vivo evaluation was carried on specimens from human renal cortex. Primary and immortalized tubular epithelial cells (TECs) and the HK-2 cell line were used as in vitro models. TREATMENT: Cells were pretreated for 10 min with chlorpheniramine maleate 10 µM (H1R antagonist), ranitidine 10 µM (H2R antagonist), GSK189254 1 µM (H3R antagonist) or JNJ7777120 10 µM (H4R antagonist), and then exposed to histamine (3 pM-10 nM) for 30 min. METHODS: The ex vivo evaluation on specimens from human renal cortex was performed by immunohistochemistry. The expression of histamine receptors on primary and immortalized TECs and the HK-2 cell line was evaluated at both gene (RT-PCR) and protein (immunocytofluorescence) levels. The pharmacological analysis was performed by TR-FRET measurements of second messenger (IP3 and cAMP) production induced by histamine with or without the selective antagonists. RESULTS: Our data revealed the presence of all histamine receptors in human tubules; however, only TECs expressed all the receptors. Indeed, histamine elicited a sigmoid dose-response curve for IP3 production, shifted to the right by chlorpheniramine maleate, and elicited a double bell-shaped curve for cAMP production, partially suppressed by the selective H2R, H3R and H4R antagonists when each added alone, and completely ablated when combined together. CONCLUSIONS: Herein, we report the identification of all four histamine receptors in human renal tubules.

H3 receptor renal expression in normal and diabetic rats.

INTRODUCTION: To extend our previous observation of H4R upregulation in the kidney of diabetic rats, we evaluated in the same specimens the presence of the H3R. MATERIALS AND METHODS: Kidney specimens from 24 8-week-old male Wistar rats (12 non-diabetic and 12 diabetic animals) were processed for both immunohistochemical and immunofluorescence analyses. RESULTS AND CONCLUSION: H3R is expressed in the apical membrane by collecting duct cells in the kidney of rats and it is significantly increased in diabetic animals. These data support the hypothesis that H3R could also mediate non-neuronal histamine effects, suggesting its involvement in fluid homeostasis.