Dietary apigenin regulates high glucose and hypoxic reoxygenation-induced reductions in apelin expression in human endothelial cells

COVID-19-Associated Sepsis: Potential Role of Phytochemicals as Functional Foods and Nutraceuticals

The acute manifestations of coronavirus disease 2019 (COVID-19) exhibit the hallmarks of sepsis-associated complications that reflect multiple organ failure. The inflammatory cytokine storm accompanied by an imbalance in the pro-inflammatory and anti-inflammatory host response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection leads to severe and critical septic shock. The sepsis signature in severely afflicted COVID-19 patients includes cellular reprogramming and organ dysfunction that leads to high mortality rates, emphasizing the importance of improved clinical care and advanced therapeutic interventions for sepsis associated with COVID-19. Phytochemicals of functional foods and nutraceutical importance have an incredible impact on the healthcare system, which includes the prevention and/or treatment of chronic diseases. Hence, in the present review, we aim to explore the pathogenesis of sepsis associated with COVID-19 that disrupts the physiological homeostasis of the body, resulting in severe organ damage. Furthermore, we have summarized the diverse pharmacological properties of some potent phytochemicals, which can be used as functional foods as well as nutraceuticals against sepsis-associated complications of SARS-CoV-2 infection. The phytochemicals explored in this article include quercetin, curcumin, luteolin, apigenin, resveratrol, and naringenin, which are the major phytoconstituents of our daily food intake. We have compiled the findings from various studies, including clinical trials in humans, to explore more into the therapeutic potential of each phytochemical against sepsis and COVID-19, which highlights their possible importance in sepsis-associated COVID-19 pathogenesis. We conclude that our review will open a new research avenue for exploring phytochemical-derived therapeutic agents for preventing or treating the life-threatening complications of sepsis associated with COVID-19.

Research progress on antisepsis effect of apigenin and its mechanism of action

Sepsis is an abnormal immune response to infections and can trigger MODS. Despite the availability of advanced clinical techniques and monitoring methods, the mortality rate of the disease is still high, posing a heavy burden to patients and the whole society. Hence, the research on novel drugs and targets is particularly important. As a natural phyto-flavonoid, apigenin boasts anti-inflammatory, antioxidant, anti-cancer, anti-viral, and anti-bacterial effects. Besides, in-vitro experiments and animal models have also revealed the crucial role of apigenin in the treatment of infectious diseases and sepsis. In this context, this paper reviews the pharmacological activity and underlying mechanisms of action of apigenin in sepsis treatment and organ protection, as well as the potential apigenin-based therapeutic strategies against sepsis. Therefore, this review will shed new light on the scientific research and clinical treatment of sepsis.

The role of apelinergic system in metabolism and reproductive system in normal and pathological conditions: an overview

Lifestyle changes have made metabolic disorders as one of the major threats to life. Growing evidence demonstrates that obesity and diabetes disrupt the reproductive system by affecting the gonads and the hypothalamus-pituitary-gonadal (HPG) axis. Apelin, an adipocytokine, and its receptor (APJ) are broadly expressed in the hypothalamus nuclei, such as paraventricular and supraoptic, where gonadotropin-releasing hormone (GnRH) is released, and all three lobes of the pituitary, indicating that apelin is involved in the control of reproductive function. Moreover, apelin affects food intake, insulin sensitivity, fluid homeostasis, and glucose and lipid metabolisms. This review outlined the physiological effects of the apelinergic system, the relationship between apelin and metabolic disorders such as diabetes and obesity, as well as the effect of apelin on the reproductive system in both gender. The apelin-APJ system can be considered a potential therapeutic target in the management of obesity-associated metabolic dysfunction and reproductive disorders.

Protective Roles of Apigenin Against Cardiometabolic Diseases: A Systematic Review

Apigenin is a flavonoid with antioxidant, anti-inflammatory, and anti-apoptotic activity. In this study, the potential effects of apigenin on cardiometabolic diseases were investigated in vivo and in vitro. Potential signaling networks in different cell types induced by apigenin were identified, suggesting that the molecular mechanisms of apigenin in cardiometabolic diseases vary with cell types. Additionally, the mechanisms of apigenin-induced biological response in different cardiometabolic diseases were analyzed, including obesity, diabetes, hypertension and cardiovascular diseases. This review provides novel insights into the potential role of apigenin in cardiometabolic diseases.

Andrographolide, a novel inducer of apelin gene expression

ETHNOPHARMACOLOGICAL RELEVANCE

Andrographis paniculata (A. paniculata) has been used as a traditional medicine in Asia and Scandinavia for centuries to remedy several illnesses. It has since been shown to possess antibacterial, antifungal, antiviral, anti-neoplasm, hepatoprotective, hypoglycemic, hypocholesterolemic, and energetic effects.

AIMS OF THE STUDY

This study sought to investigate the effect of Andrographolide on apelin gene expression and serum levels of glucose.

MATERIALS AND METHODS

In this study, 18 male rats were used. They were divided into three groups of six, including i) negative control group, ii) 3.5 mg/kg Andrographolide group, and iii) 7 mg/kg Andrographolide group. Apelin gene expression was investigated by real-time PCR method. Serum levels of glucose were measured by the photometric method.

RESULTS

The results of this study revealed that 3.5 and 7 mg doses per kg of body weight of andrographolide, for six days, significantly increased hepatic expression of apelin gene in male Wistar rats, as compared with the control group (p < 0.05). Serum levels of glucose at doses of 3.5 and 7 mg/kg of andrographolide, and in the control group, were 71.5 ± 8.96, 51.5 ± 2.64, and 93.87 ± 14.27 mg/dl, respectively. Andrographolide induced a decrease in serum levels of HDL-c and an increase in LDL-c/HDL-c ratio.

CONCLUSIONS

Our results suggest that Andrographolide can elicit an increase of hepatic apelin gene expression and a decrease in serum levels of blood glucose.

Region-specific changes in the mRNA and protein expression of LCPUFA biosynthesis enzymes and transporters in the placentae of women with preeclampsia

The biosynthesis and transport of long chain polyunsaturated fatty acids (LCPUFA) require the activity of fatty acid desaturase (FADS) enzymes, fatty acid transport proteins (FATP) and fatty acid binding proteins (FABP). In a previous study we have demonstrated region-specific changes in the LCPUFA levels in preeclampsia (PE) as compared to the normotensive control (NC) placentae.

AIM

To understand the region-specific changes in the mRNA levels and protein expression of biosynthesis enzymes and transporters of LCPUFA in PE and NC placentae.

METHODS

In this cross-sectional study, 20 NC women and 44 women with PE (23 term (TPE) and 21 preterm PE (PTPE)) were recruited. The samples were collected from four regions of the placentae considering cord insertion as the center (CM, central maternal/basal; CF, central fetal/chorionic; PM, peripheral maternal/basal and PF, peripheral fetal/chorionic). The mRNA levels were estimated using qRT-PCR. Statistical analysis was done using both post hoc least significant difference (LSD) test and Benjamini Hochberg correction in the analysis of covariance. Preliminarily, localization and expression of proteins were studied by immunohistochemistry (n = 3/group).

RESULTS

The mRNA levels of FADS1, FADS2 and FATP1 were lower in the central regions (CM and CF) of the PE placentae (both TPE and PTPE) as compared to NC. These differences in the mRNA levels were observed by the LSD test and were not significant after the Benjamini Hochberg correction. Preliminary findings of IHC indicate that the protein expression of FADS1 and FATP4 was higher in the basal regions (CM and PM) of the PE placentae as compared to NC. FADS1, FADS2 and FATP4 proteins were localized in the syncytiotrophoblasts, cytotrophoblasts, mesenchymal cells, endothelial cells of the fetal capillaries and extravillous trophoblasts of the placenta.

CONCLUSION

FADS enzymes are detected in the placentae of Indian women. In PE placentae, there are region-specific alterations in the mRNA and protein levels of LCPUFA biosynthesis enzymes (FADS1 and FADS2) and transporters (FATP1, FATP4 and FABP3) as compared to term NC. These changes were more pronounced toward the basal side and region around the cord insertion.

Novel apigenin-loaded sodium hyaluronate nano-assemblies for targeting tumor cells

We aimed to construct a novel nano-assembly carrying apigenin (APG), a hydrophobic drug, and to evaluate its in vitro targeting ability for A549 cells overexpressing CD44 receptors. The apigenin-loaded sodium hyaluronate nano-assemblies (APG/SH-NAs) were assembled by multiple non-covalent interactions between sodium hyaluronate (SH) and APG. The prepared APG/SH-NAs exhibited a small average size and narrow particle size distribution. In addition, satisfactory encapsulation efficiency and drug loading were obtained. The drug release curves indicated that APG/SH-NAs achieved a sustainable drug-release effect due to the presence of hydrophilic materials. The in vitro cytotoxicity of APG/SH-NAs against A549 cells and HepG2 cells was evaluated, and the results indicated that the prepared APG/SH-NA showed higher cytotoxicity compared to apigenin suspensions. When CD44 receptors on the surface of A549 cells were blocked by the addition of excess SH, the cytotoxicity of APG/SH-NA was significantly reduced. However, similar phenomena were not observed in HepG2 cells with relatively low CD44 receptor expression. The resulting APG/SH-NAs could efficiently facilitate the internalization of APG into A549 cells, which might be due to their high affinity for CD44 receptors. Moreover, the apoptotic rate of APG/SH-NAs through receptor-mediated endocytosis mechanism was higher than that of the other groups in A549 cells. Thus, such nano-assemblies were considered to be an effective transport system with excellent affinity for CD44 receptors to allow the SH-mediated targeted delivery of APG.

Microwave-assisted simultaneous extraction of luteolin and apigenin from tree peony pod and evaluation of its antioxidant activity

An efficient microwave-assisted extraction (MAE) technique was employed in simultaneous extraction of luteolin and apigenin from tree peony pod. The MAE procedure was optimized using response surface methodology (RSM) and compared with other conventional extraction techniques of macerate extraction (ME) and heat reflux extraction (HRE). The optimal conditions of MAE were as follows: employing 70% ethanol volume fraction as solvent, soaking time of 4 h, liquid-solid ratio of 10 (mL/g), microwave irradiation power of 265 W, microwave irradiation time of 9.6 min, and 3 extraction cycles. Under the optimal conditions, 151 μg/g luteolin and 104 μg/g apigenin were extracted from the tree peony pod. Compared with ME and HRE, MAE gave the highest extraction efficiency. The antioxidant activities of the extracts obtained by MAE, ME, and HRE were evaluated using a 2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl (DPPH) free radical-scavenging assay, a ferric reducing antioxidant power assay (FRAP), and a reducing power assay. Meanwhile, the structural changes of the unprocessed and processed tree peony pod samples were analyzed by scanning electron microscopy.

Dietary polyphenols regulate endothelial function and prevent cardiovascular disease

Vascular endothelial cell (EC) dysfunction strongly induces development of cardiovascular and cerebrovascular diseases. Epidemiologic studies demonstrated a preventative effect of dietary polyphenols toward cardiovascular disease. In studies using cultured vascular ECs, polyphenols were recognized to regulate nitric oxide and endothelin-1 (ET-1) production. Furthermore, epigallocatechin-3-gallate inhibited the expression of adhesion molecules by a signaling pathway that is similar to that of high-density lipoprotein and involves induction of Ca(2+)/calmodulin-dependent kinase II, liver kinase B, and phosphatidylinositol 3-kinase expression. The effects of polyphenols on ECs include antioxidant activity and enhancement of the expression of several protective proteins, including endothelial nitric oxide synthase and paraoxonase 1. However, the observed effects of dietary polyphenols in vitro do not always translate to an in vivo setting. As such, there are many questions concerning their physiological mode of action. In this review, we discuss research on the effect of dietary polyphenols on cardiovascular disease and their protective effect on EC dysfunction.

The intestinal glucose-apelin cycle controls carbohydrate absorption in mice

BACKGROUND & AIMS

Glucose is absorbed into intestine cells via the sodium glucose transporter 1 (SGLT-1) and glucose transporter 2 (GLUT2); various peptides and hormones control this process. Apelin is a peptide that regulates glucose homeostasis and is produced by proximal digestive cells; we studied whether glucose modulates apelin secretion by enterocytes and the effects of apelin on intestinal glucose absorption.

METHODS

We characterized glucose-related luminal apelin secretion in vivo and ex vivo by mass spectroscopy and immunologic techniques. The effects of apelin on (14)C-labeled glucose transport were determined in jejunal loops and in mice following apelin gavage. We determined levels of GLUT2 and SGLT-1 proteins and phosphorylation of AMPKα2 by immunoblotting. The net effect of apelin on intestinal glucose transepithelial transport was determined in mice.

RESULTS

Glucose stimulated luminal secretion of the pyroglutaminated apelin-13 isoform ([Pyr-1]-apelin-13) in the small intestine of mice. Apelin increased specific glucose flux through the gastric epithelial barrier in jejunal loops and in vivo following oral glucose administration. Conversely, pharmacologic apelin blockade in the intestine reduced the increased glycemia that occurs following oral glucose administration. Apelin activity was associated with phosphorylation of AMPKα2 and a rapid increase of the GLUT2/SGLT-1 protein ratio in the brush border membrane.

CONCLUSIONS

Glucose amplifies its own transport from the intestinal lumen to the bloodstream by increasing luminal apelin secretion. In the lumen, active apelin regulates carbohydrate flux through enterocytes by promoting AMPKα2 phosphorylation and modifying the ratio of SGLT-1:GLUT2. The glucose-apelin cycle might be pharmacologically handled to regulate glucose absorption and assess better control of glucose homeostasis.