The bioflavonoid quercetin improves pathophysiology in a rat model of preeclampsia

Chitosan-TPP encapsulated quercetin nanoparticles: amplified protection mechanisms unveiled against Ethion-induced developmental toxicity through comprehensive in-vivo and in-silico elucidation

Aim

The study investigated Ethion-induced developmental toxicity in Wistar albino rats and the potential ameliorative effects of quercetin and nano-quercetin co-administration. Further, In-silico docking of Ethion and quercetin with MCL-1 was conducted.

Methodology

Quercetin nanoparticles were synthesized by ionic-gelation method. The encapsulated quercetin nanoparticles were characterized for Zeta size, UV-Vis spectroscopy, encapsulation efficiency, and TEM studies. Male rats were administered Ethion (high/low dose), quercetin, and nano-quercetin alone or in combination for 60 days. Female rats were introduced for mating on the 61st day, and pregnant females were observed for 20 gestational days. On GD 20, rats were sacrificed and evaluated for body/organ weight, reproductive indices, fetal morphology, skeletal, and visceral deformities.In silico binding energies of ethion and quercetin with MCL-1 were determined.

Results

Nanoparticle size was 363.2 ± 1.23 nm on day 0 and 385.63 ± 1.53 nm on day 60, with PDI of 0.247 and charge of 22.9 mV. Absorbance maxima were at 374 nm, with encapsulation efficacy of 85.16 ± 0.33%. EHD male crossed females showed decreased body/organ weights, reduced fertility, hematoma, cleft palate, tail curling, and absence of extremity. Nano-quercetin co-administration normalized parameters comparable to controls. Both Ethion and quercetin interacted with MCL-1, with quercetin exhibiting stronger binding energy.

Conclusion

Nano-quercetin demonstrated stronger antioxidant properties than quercetin, counteracting ethion-induced maternal/fetal abnormalities.

Protective Effects of Aspirin Supplemented With Quercetin in L-NAME-Induced Preeclampsia-Like Rats

Aspirin supplemented with quercetin was reported to enhance the therapeutic effects of aspirin in a rat model of preeclampsia. In this study, the underlying mechanisms were further explored. Preeclampsia was induced by L-NAME (50 mg/kg/day) via oral gavage from gestation day (GD)14 to GD19. Aspirin (1.5 mg/kg/day) administration was performed using aspirin mixed with rodent dough from GD0 to GD19. The administration of quercetin (2 mg/kg/day) was performed by intraperitoneal infusion from GD0 to GD19. Protein levels were evaluated using ELISA or Western blot, and microRNA (miRNA) level was evaluated by RT-PCR. Aspirin supplemented with quercetin ameliorated the increase of systolic blood pressure (SBP), proteinuria, tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) levels, and improved the pregnancy outcomes in preeclampsia rats. Aspirin supplemented with quercetin inhibited miR-155 expression in preeclampsia rats. The decreased miR-155 level in placenta further increased the protein level of SOCS1 and inhibited the phosphorylation of p65. In this study, we demonstrated that aspirin supplemented with quercetin enhanced the effects of aspirin for the treatment of preeclampsia.

Exploring the Role of Mediterranean and Westernized Diets and Their Main Nutrients in the Modulation of Oxidative Stress in the Placenta: A Narrative Review

Oxidative stress is a major cellular event that occurs in the placenta, fulfilling critical physiological roles in non-pathological pregnancies. However, exacerbated oxidative stress is a pivotal feature of different obstetric complications, like pre-eclampsia, fetal growth restriction, and other diseases. Compelling evidence supports the relevant role of diet during pregnancy, with pleiotropic consequences for maternal well-being. The present review aims to examine the complex background between oxidative stress and placental development and function in physiological conditions, also intending to understand the relationship between different dietary patterns and the human placenta, particularly how this could influence oxidative stress processes. The effects of Westernized diets (WDs) and high-fat diets (HFDs) rich in ultra-processed foods and different additives are compared with healthy patterns such as a Mediterranean diet (MedDiet) abundant in omega 3 polyunsaturated fatty acids, monounsaturated fatty acids, polyphenols, dietary fiber, and vitamins. Although multiple studies have focused on the role of specific nutrients, mostly in animal models and in vitro, further observational and intervention studies focusing on the placental structure and function in women with different dietary patterns should be conducted to understand the precise influence of diet on this organ.

Bioflavonoid luteolin prevents sFlt-1 release via HIF-1α inhibition in cultured human placenta

Preeclampsia (PE) is a serious hypertensive complication of pregnancy and is a leading cause of maternal death and major contributor to maternal and perinatal morbidity, including establishment of long-term complications. The continued prevalence of PE stresses the need for identification of novel treatments which can target prohypertensive factors implicated in the disease pathophysiology, such as soluble fms-like tyrosine kinase 1 (sFlt-1). We set out to identify novel compounds to reduce placental sFlt-1 and determine whether this occurs via hypoxia-inducible factor (HIF)-1α inhibition. We utilized a commercially available library of natural compounds to assess their ability to reduce sFlt-1 release from primary human placental cytotrophoblast cells (CTBs). Human placental explants from normotensive (NT) and preeclamptic (PE) pregnancies were treated with varying concentrations of luteolin. Protein and mRNA expression of sFlt-1 and upstream mediators were evaluated using ELISA, western blot, and real-time PCR. Of the natural compounds examined, luteolin showed the most potent inhibition of sFlt-1 release, with >95% reduction compared to vehicle-treated. Luteolin significantly inhibited sFlt-1 in cultured placental explants compared to vehicle-treated in a dose- and time-dependent manner. Additionally, significant decreases in HIF-1α expression were observed in luteolin-treated explants, suggesting a mechanism for sFlt-1 downregulation. The ability of luteolin to inhibit HIF-1α may be mediated through the Akt pathway, as inhibitors to Akt and its upstream regulator phosphatidylinositol-3 kinase (PI3K) resulted in significant HIF-1α reduction. Luteolin reduces anti-angiogenic sFlt-1 through inhibition of HIF-1α, making it a novel candidate for the treatment of PE.

New Ideas for the Prevention and Treatment of Preeclampsia and Their Molecular Inspirations

Preeclampsia (PE) is a pregnancy-specific disorder affecting 4-10% of all expectant women. It greatly increases the risk of maternal and foetal death. Although the main symptoms generally appear after week 20 of gestation, scientific studies indicate that the mechanism underpinning PE is initiated at the beginning of gestation. It is known that the pathomechanism of preeclampsia is strongly related to inflammation and oxidative stress, which influence placentation and provoke endothelial dysfunction in the mother. However, as of yet, no "key players" regulating all these processes have been discovered. This might be why current therapeutic strategies intended for prevention or treatment are not fully effective, and the only effective method to stop the disease is the premature induction of delivery, mostly by caesarean section. Therefore, there is a need for further research into new pharmacological strategies for the treatment and prevention of preeclampsia. This review presents new preventive methods and therapies for PE not yet recommended by obstetrical and gynaecological societies. As many of these therapies are in preclinical studies or under evaluation in clinical trials, this paper reports the molecular targets of the tested agents or methods.

Common pregnancy complications and polyphenols intake: an overview

During pregnancy, the body undergoes a great amount of changes in order to support a healthy developing fetus. In this context, maternal dietary supplementation is widely encouraged to provide adequate nutrition for the newborn. In the past few years, studies have emerged highlighting the benefits of polyphenols intake during pregnancy. Indeed, despite differences among reports, such as experimental model, polyphenol employed, dosage and regimen of administration, there is no doubt that the ingestion of these molecules has a protective effect in relation to three pregnancy-associated diseases or conditions: preeclampsia, gestational diabetes and fetal growth restriction. In this review, we describe the effects of different polyphenols and polyphenol-rich extracts or juices on the main outcomes of these common pregnancy-associated complications, obtained in human, animal and in vitro studies. Therefore, this work provides a critical analysis of the literature, and a summary of evidences, from which future research using polyphenols can be designed and evaluated.

The Role of Dietary Polyphenols in Pregnancy and Pregnancy-Related Disorders

Polyphenols are a group of phytochemicals with extensive biological functions and health-promoting potential. These compounds are present in most foods of plant origin and their increased widespread availability through the intake of nutritional supplements, fortified foods, and beverages, has also led to increased exposure throughout gestation. In this narrative review, we focus on the role of polyphenols in both healthy and pathological pregnancy. General information related to their classification and function is followed by an overview of their known effects in early-pregnancy events, including the current insights into molecular mechanisms involved. Further, we provide an overview of their involvement in some of the most common pregnancy-associated pathological conditions, such as preeclampsia and gestational diabetes mellitus. Additionally, we also discuss the estimated possible risk of polyphenol consumption on pregnancy outcomes. The consumption of dietary polyphenols during pregnancy needs particular attention considering the possible effects of polyphenols on the mechanisms involved in maternal adaptation and fetal development. Further studies are strongly needed to unravel the in vivo effects of polyphenol metabolites during pregnancy, as well as their role on advanced maternal age, prenatal nutrition, and metabolic risk of the offspring.

Quercetin Supplement to Aspirin Attenuates Lipopolysaccharide-Induced Pre-eclampsia-Like Impairments in Rats Through the NLRP3 Inflammasome

BACKGROUND AND OBJECTIVES

Aspirin is a common drug for the treatment of pre-eclampsia. We aimed to explore whether quercetin as a supplement to aspirin could enhance the therapeutic outcome in pre-eclampsia rat models. We further aimed to evaluate the nucleotide-binding oligomerization domain-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome as a potential pre-eclampsia-related molecular mechanism, which can be affected by quercetin treatment.

METHODS

Rat pre-eclampsia models were established using an intravenous lipopolysaccharide injection after gestation. Rats were treated with aspirin and quercetin at 6-18 days after pregnancy. On day 20, blood, fetus, and placenta were harvested. Blood pressure and the level of proteinuria were measured every 4 days. Fetal outcomes were analyzed by pup body weight. Serum soluble Fms-like tyrosine kinase-1, PIGF, interleukin-6, and interleukin-10 levels were measured using the enzyme-linked immunosorbent assay. Caspase-1, NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain, and p-caspase-1 levels in the placenta were assessed using western blot or quantitative real-time polymerase chain reaction analyses.

RESULTS

Pre-eclampsia rat models showed a pronounced increase in systolic blood pressure and proteinuria after 4 days of pregnancy, while aspirin, quercetin, and aspirin/quercetin combinatory treatment significantly attenuated the blood pressure and proteinuria abnormalities. Notably, the aspirin/quercetin combinatory treatment showed the highest efficacy in attenuating pre-eclampsia-like symptoms. Placental caspase-1 and NLRP3 levels also showed the greatest attenuation in pre-eclampsia rats after aspirin/quercetin treatment.

CONCLUSIONS

Our data suggested that quercetin supplementation to aspirin is more effective in attenuating symptoms of pre-eclampsia and improving pregnancy outcomes compared with quercetin or aspirin alone. Quercetin can ameliorate placental NLRP3 inflammasome activation, which might serve as an underlying mechanism for its therapeutic efficacies in pre-eclampsia.

Evidence for Quercetin as a Dietary Supplement for the Treatment of Cardio-Metabolic Diseases in Pregnancy: A Review in Rodent Models

Quercetin supplementation during pregnancy and lactation has been linked to a lower risk of maternal cardio-metabolic disorders such as gestational diabetes mellitus (GDM), dyslipidemia, preeclampsia, attenuation of malnutrition-related conditions, and gestational obesity in animal studies. Pre-clinical studies have shown that maternal supplementation with quercetin reduces cardio-metabolic diseases in dams and rodents’ offspring, emphasizing its role in modifying phenotypic plasticity. In this sense, it could be inferred that quercetin administration during pregnancy and lactation is a viable strategy for changing cardio-metabolic parameters throughout life. Epigenetic mechanisms affecting the AMP-activated protein kinase (AMPK), nuclear factor-kappa B (NF-κB), and phosphoinositide 3-kinase (PI3 K) pathways could be associated with these changes. To highlight these discoveries, this review outlines the understanding from animal studies investigations about quercetin supplementation and its capacity to prevent or decrease maternal and offspring cardio-metabolic illnesses and associated comorbidities.

Pravastatin, proton-pump inhibitors, metformin, micronutrients, and biologics: new horizons for the prevention or treatment of preeclampsia

There has been increasing research momentum to identify new therapeutic agents for the prevention or treatment of preeclampsia, drugs that can affect the underlying disease pathophysiology. Molecular targets of candidate treatments include oxidative stress, antiangiogenic factors, and the angiotensin, nitric oxide, and proinflammatory pathways. The proposed treatments undergoing preclinical and clinical trial evaluation are thought to act on placental or endothelial disease or both. Most have adopted the pragmatic strategy of repurposing drugs. Of all the therapeutic agents proposed, pravastatin has received the most interest. There are preclinical studies showing that it has pleiotropic actions that favorably impact on multiple molecular targets and can resolve a preeclampsia phenotype in many animal models. An early phase clinical trial suggests that it may have therapeutic activity. Several large prevention trials are planned or ongoing and, when completed, could definitively address whether pravastatin can prevent preeclampsia. Proton-pump inhibitors, metformin, and sulfasalazine are other drugs with preclinical evidence of multiple molecular actions that could resolve the pathophysiology of preeclampsia. These agents are also currently being evaluated in clinical trials. There have been many recent preclinical studies identifying the potential of numerous natural compounds to treat preeclampsia, such as plant extracts and micronutrients that have potent anti-inflammatory or antioxidant activity. Recent preclinical studies have also proposed novel molecular-targeted strategies, such as monoclonal antibodies targeting tumor necrosis factor alpha, placental growth factor, and short interfering RNA technology, to silence the gene expression of soluble fms-like tyrosine kinase-1 or angiotensinogen. Other treatment approaches that have transitioned to human trials (ranging from single-arm to phase III trials that have been completed or are ongoing) include folic acid, nitric oxide donors (such as L-arginine), recombinant antithrombin III, digoxin immune antigen-binding fragment, and melatonin. There have been case series showing the removal of circulating soluble fms-like tyrosine kinase-1 may help stabilize the disease and prolong pregnancy. Interestingly, there are case reports suggesting that monoclonal antibody eculizumab (complement inhibitor) may have therapeutic potential. If new agents are discovered that are proven to be effective in preventing or treating preeclampsia, the potential to improve global maternal and perinatal health will be significant.

Chitosan/Hyaluronic acid/Alginate and an assorted polymers loaded with honey, plant, and marine compounds for progressive wound healing-Know-how

Biomaterials are being extensively used in regenerative medicine including tissue engineering applications, as these enhance tissue development, repair, and help in the process of angiogenesis. Wound healing is a crucial biological process of regeneration of ruptured tissue after getting injury to the skin and other soft tissue in humans and animals. Besides, the accumulation of microbial biofilms around the wound surface can increase the risk and physically obstruct the wound healing activity, and may even lead to amputation. Hence, in both acute and chronic wounds, prominent biomaterials are required for wound healing along with antimicrobial agents. This review comprehensively addresses the antimicrobial and wound healing effects of chitosan, chitin, cellulose acetate, hyaluronic acid, pullulan, bacterial cellulose, fibrin, alginate, etc. based wound dressing biomaterials fabricated with natural resources such as honey, plant bioactive compounds, and marine-based polymers. Due to their excellent biocompatibility and biodegradability, bioactive compounds derived from honey, plants, and marine resources are commonly used in biomedical and tissue engineering applications. Different types of polymer-based biomaterials including hydrogel, film, scaffold, nanofiber, and sponge dressings fabricated with bioactive agents including honey, curcumin, tannin, quercetin, andrographolide, gelatin, carrageenan, etc., can exhibit significant wound healing process in, diabetic wounds, diabetic ulcers, and burns, and help in cartilage repair along with good biocompatibility and antimicrobial effects. Among the reviewed biomaterials, carbohydrate polymers such as chitosan-based biomaterials are prominent and widely used for wound healing applications followed by hyaluronic acid and alginate-based biomaterials loaded with honey, plant, and marine compounds. This review first provides an overview of the vast natural resources used to formulate different biomaterials for the treatment of antimicrobial, acute, and chronic wound healing processes.

Protective role of SIRT1-mediated Sonic Hedgehog signaling pathway in the preeclampsia rat models

OBJECTIVE

To explore the role of silent information regulator 1 (SIRT1)-mediated Sonic Hedgehog (SHH) pathway in reduced uterine perfusion pressure (RUPP) model of preeclampsia (PE) in rats.

METHODS

The pregnant rats were divided into sham, RUPP, RUPP + rSIRT1 (recombinant SIRT1 protein), RUPP + rSHH (recombinant SHH protein), and RUPP + rSIRT1+ Cy (cyclopamine, an SHH pathway inhibitor) groups, followed by the determination of mean arterial pressure (MAP) and pregnancy outcome. The gene or protein expression was determined by enzyme-linked immunosorbent assay (ELISA), quantitative reverse transcription-polymerase chain reaction (qRT-PCR), or Western blotting.

RESULTS

RUPP rats showed increases MAP with the lower levels of vascular endothelial growth factor (VEGF) and nitrite and nitrate (NOx), as well as the higher levels of soluble FMS-like tyrosine kinase-1 (sFlt-1), tumor necrosis factor (TNF)-α, and interleukin (IL)-6 in maternal plasma, which was attenuated after rSIRT1 or rSHH treatment. Besides, the improvement in the pregnancy outcome was seen in the rats from the RUPP + rSIRT1/rSHH groups as compared with the RUPP group. However, the therapeutic effect of rSIRT1 was reversed by cyclopamine. Placenta tissues of RUPP rats manifested the down-regulations of SIRT1, Patched-1 (PTCH1), and GLI family zinc finger 2 (GLI2), which were up-regulated in the RUPP + rSIRT1 group.

CONCLUSION

SIRT1 was down-regulated while SHH pathway was inhibited in the placental tissue of PE rats. SIRT1 improved the blood pressure, angiogenic imbalance, inflammation, and pregnancy outcome in PE rats via SHH pathway, supporting its potential use for the treatment of PE.

Plant Phenolics and Extracts in Animal Models of Preeclampsia and Clinical Trials-Review of Perspectives for Novel Therapies

The current health requirements set the direction in pharmacological research, especially as regards diseases that require improvement of existing therapeutic regimens. Such diseases include preeclampsia, which is a hypertensive disorder of pregnancy during which there occurs progressive increasing activation of the immune system through elevation of pro-inflammatory cytokines and antiangiogenic factors, which is dangerous for the mother and fetus. A promising field of research for new drugs to treat this disease is the study of natural phenolic compounds of plant origin and herbal extracts, which are complex matrices of chemical compounds with broad biological activities. Many plant substances with anti‑inflammatory and anti‑hypertensive properties are known, but studies in animal models of preeclampsia and clinical trials concerning this disease constitute a new and developing research trend of significant medical importance. The aim of our research review was to identify and analyze the results of already available studies on baicalin, curcumin, epigallocatechin gallate, punicalagin, quercetin, resveratrol, salvianolic acid A (danshensu), silibinin, and vitexin, as well as plant extracts from Brassica oleracea L., Euterpe oleracea Mart., Moringa oleifera Lam., Punica granatum L., Silybum marianum (L.) Gaertner, Thymus schimperi Ronniger, Uncaria rhynchophylla (Miq.) Miq. ex Havil., and Vitis vinifera L., which are potential and promising candidates for further research and for potential new therapies.

Correlation between Apelin and Some Angiogenic Factors in the Pathogenesis of Preeclampsia: Apelin-13 as Novel Drug for Treating Preeclampsia and Its Physiological Effects on Placenta

Preeclampsia (PE) is one of the commonest causes for maternal and fetal morbidity and mortality. Imbalances of angiogenic factors, oxidative stress, and inflammatory response have a role in the pathogenesis of PE. Data regarding the circulating apelin level and its role in PE remains controversial. This study was formulated to assess the serum apelin level in PE, investigate its correlation with some inflammatory, oxidative stress, and angiogenic proteins in a nitric oxide synthase inhibitor; the N (gamma)-nitro-L-arginine methyl ester (L-NAME)-induced rat model of PE and determine whether apelin administration could protect against development of PE. 40 healthy adult female albino rats and 10 adult male albino rats were used in this study. The pregnant female rats were randomly divided into three groups: group 1 (normal pregnant group), group 2 (PE-induced group), injected subcutaneously with 75 mg L-NAME/kg bodyweight/day starting from day 9 to 20 of gestation, and group 3 (PE-induced group supplemented with apelin (PE + apelin)); PE induced as before and simultaneously subcutaneously injected with apelin-13 (6 × 10^-8 mol/kg bodyweight/twice daily) beginning from day 6 to 20 of gestation. In all groups, blood pressure and urine protein were determined at gestation days (GD) 0, 10, and 18. Moreover, serum apelin, placental growth factor (PLGF), vascular endothelial growth factor (VEGF), soluble fms-like tyrosine kinase-1 (sFlt-1), soluble endoglin (sEng), interferon-gamma (IFN-γ), and interleukin-10 (IL-10) levels and serum superoxide dismutase enzyme (SOD) and catalase (CAT) activities of all groups were estimated at the end of experiment. Placental histopathological examination was also performed. PE-induced rats showed significantly decreased serum apelin levels. Moreover, they showed significantly increased blood pressures, urine proteins, sFlt-1, sEng, and IFN-γ (mean arterial blood pressure, urine proteins, sFlt-1, sEng, and IFN-γ showed significant negative correlations with serum apelin level), but it showed significantly decreased VEGF, PLGF, IL-10, SOD, and CAT (VEGF, PLGF, IL-10, and SOD showed significant positive correlations with serum apelin level). In contrast, exogenous apelin administration significantly ameliorated these parameters together with improvement in the placental histoarchitecture in the apelin-supplemented PE group. This study demonstrated the protective effects of apelin administration on the pathogenesis of PE.