Hesperidin Preferentially Stimulates Transient Receptor Potential Vanilloid 1, Leading to NO Production and Mas Receptor Expression in Human Umbilical Vein Endothelial Cells

The extract from Quzhou Aurantii Fructus attenuates cough variant asthma through inhibiting the TRPV1/Ca2+/NFAT/TSLP pathway and ferroptosis via TRPV1 mediation in ovalbumin-induced mice

ETHNOPHARMACOLOGICAL RELEVANCE

Cough variant asthma (CVA), a prevalent chronic inflammatory disease, is the most common cause of chronic cough. Over the years, the aqueous extract of Quzhou Aurantii Fructus (QAFA) has been widely used to treat respiratory diseases, particularly cough.

AIM OF THE STUDY

This study aimed to elucidate the therapeutic effect of QAFA on allergen-induced CVA, providing deep insights into the underlying mechanisms.

MATERIALS AND METHODS

Ultra-high performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) was employed to characterize the compositions, while UPLC was used to quantify the contents of its major components in QAFA. CVA model was established via sensitization and atomization with ovalbumin (OVA), and received 600 and 1200 mg/kg of QAFA via intragastric gavage. Cough response was assessed by stimulation with capsaicin (CAP). Then, airway hyperresponsiveness (AHR), ELISA, western blotting, RT-qPCR, and histological analyses, were applied to assess pulmonary function, pathological changes, and investigate mechanisms in CVA mice following QAFA treatment through the TRPV1/Ca2+-dependent NFAT-induced expression of TSLP and ferroptosis. Additionally, the effects and mechanisms of QAFA were validated using IL-4, CAP for stimulation, capsazepine (CPZ) for inhibition, and TRPV1 siRNA transfection in cells.

RESULTS

Chemical analysis revealed that QAFA primarily contained sixteen compounds, with four main components including narirutin, naringin, hesperidin, and neohesperidin. In vivo, QAFA treatment alleviated cough and AHR, while concurrently reducing airway inflammation and mucus secretion in CVA mice. These effects were achieved by suppressing the TRPV1/NFAT/TSLP pathway and modulating the expression of ferroptosis-related proteins. In vitro, siTRPV1-transfected BEAS-2B cells demonstrated the involvement of the TRPV1 channel in IL-4-mediated Ca2+ influxes, ferroptosis, and regulation of TSLP production. QAFA and CPZ suppressed IL-4-induced TSLP production via the TRPV1/NFAT pathway and regulated the levels of ferroptosis-related proteins, while CAP counteracted the effect of QAFA on TSLP production in BEAS-2B cells. Furthermore, QAFA reduced IL-4 or CAP induced Ca2+ influx and IL-4 induced ferroptosis through TRPV1 mediation.

CONCLUSIONS

This study demonstrated that QAFA improved pulmonary function and alleviated asthmatic inflammatory response in treating CVA probably through suppressing the TRPV1/Ca2+/NFAT/TSLP pathway and ferroptosis via TRPV1 mediation.

Sulfated and Glucuronidated Conjugates of 3-(4-Hydroxy-3-methoxyphenyl) Propionic Acid Can Promote NO Production by Elevated Ca2+ Release from the Endoplasmic Reticulum in HUVECs

We aimed to clarify whether metabolic conjugates of sulfated and glucuronidated forms have the physiological potential to produce the vasorelaxant nitric oxide (NO) in human umbilical vein endothelial cells (HUVECs), using 3-(4-hydroxy-3-methoxyphenyl) propionic acid (HMPA), a metabolite of dietary flavonoids in the gut. Treatment of HUVECs with sulfated and glucuronidated HMPAs significantly increased NO production and eNOS phosphorylation. A transporter-inhibitor-aided cellular uptake experiment of HMPAs revealed that both conjugates were incorporated into cells via MCT, OATP1A2, and GLUT transporters, whereas intact HMPA was transported via the MCT and OATP1A2 routes. A Fluo-4-probe Ca2+ assay demonstrated that the incorporated HMPAs significantly increased intracellular Ca2+ concentration by stimulating the IP3R of the endoplasmic reticulum in the CaMKII/eNOS signaling cascade. In conclusion, to our knowledge, this study provides the first evidence that sulfated and glucuronidated forms of HMPAs may stimulate NO production in HUVECs.

Bioactive Flavonoids in Protecting Against Endothelial Dysfunction and Atherosclerosis

Atherosclerosis is a common cardiovascular disease closely associated with factors such as hyperlipidaemia and chronic inflammation. Among them, endothelial dysfunction serves as a major predisposing factor. Vascular endothelial dysfunction is manifested by impaired endothelium-dependent vasodilation, enhanced oxidative stress, chronic inflammation, leukocyte adhesion and hyperpermeability, endothelial senescence, and endothelial-mesenchymal transition (EndoMT). Flavonoids are known for their antioxidant activity, eliminating oxidative stress induced by reactive oxygen species (ROS), thereby preventing the oxidation of low-density lipoprotein (LDL) cholesterol, reducing platelet aggregation, alleviating ischemic damage, and improving vascular function. Flavonoids have also been shown to possess anti-inflammatory activity and to protect the cardiovascular system. This review focuses on the protective effects of these naturally-occuring bioactive flavonoids against the initiation and progression of atherosclerosis through their effects on endothelial cells including, but not limited to, their antioxidant, anti-inflammatory, anti-thrombotic, and lipid-lowering properties. However, more clinical evidences are still needed to determine the exact role and optimal dosage of these compounds in the treatment of atherosclerosis.

Therapeutic potential of hesperidin in diabetes mellitus-induced erectile dysfunction through Nrf2-mediated ferroptosis and oxidative stress

BACKGROUND

Among erectile dysfunction (ED) caused by metabolic abnormalities, diabetes mellitus-induced ED (DMED) progresses rapidly, manifests with severe symptoms, and shows reduced responsiveness to conventional medications. Hyperglycemia in the corpus cavernosum has been linked to the induction of both ferroptosis and oxidative stress, which are mediated by nuclear factor E2 related factor 2 (Nrf2). Hesperidin (Hes), a flavonoid compound, has been revealed to activate Nrf2 in certain diabetic complications, yet the efficacy of Hes on DMED and the specific mechanism remain unclear.

OBJECTIVES

To elucidate the potential mechanism and efficacy of Hes in regulating Nrf2-mediated ferroptosis and oxidative stress in DMED.

MATERIALS AND METHODS

DMED rats were constructed through the intraperitoneal injection of streptozotocin (STZ), partially supplemented with Hes. In parallel, in vitro research utilized human umbilical vein endothelial cells (HUVECs), with glucose addition to simulating a high glucose (HG) environment, and induced with Hes or ML385 (an Nrf2 inhibitor). Penile tissues and HUVECs were harvested for subsequent analyses.

RESULTS

The results of this study indicate that Hes partially reversed the impaired erectile function. The expression of Nrf2, glutathione peroxidase 4 (GPX4), and heme oxygenase-1 (HO-1) in the corpus cavernosum elevated after supplementing with Hes, resulted in an inhibition in ferroptosis and oxidative stress. Moreover, the quantity and function of erectile effector cells were restored, and cavernous fibrosis was ameliorated. In HG-induced HUVECs, Hes ameliorated Nrf2-mediated ferroptosis and oxidative stress, effects which ML385 partially reversed.

CONCLUSIONS

Hes exerts a therapeutic effect on DMED rats and a regulatory mechanism on the Nrf2-HO-1/GPX4 axis, concurrently revitalizing endothelial and smooth muscle cells, and diminishing fibrosis. Our study provides robust preclinical evidence for employing Hes in treating DMED.

Recent understanding of the mechanisms of the biological activities of hesperidin and hesperetin and their therapeutic effects on diseases

Flavonoids are natural phytochemicals that have therapeutic effects and act in the prevention of several pathologies. These phytochemicals can be found in lemon, sweet orange, bitter orange, clementine. Hesperidin and hesperetin are citrus flavonoids from the flavanones subclass that have anti-inflammatory, antioxidant, antitumor and antibacterial potential. Preclinical studies and clinical trials demonstrated therapeutical effects of hesperidin and its aglycone hesperetin in various diseases, such as bone diseases, cardiovascular diseases, neurological diseases, respiratory diseases, digestive diseases, urinary tract diseases. This review provides a comprehensive overview of the biological activities of hesperidin and hesperetin, their therapeutic potential in various diseases and their associated molecular mechanisms. This article also discusses future considerations for the clinical applications of hesperidin and hesperetin.

Research Progress of Flavonoids Regulating Endothelial Function

The endothelium, as the guardian of vascular homeostasis, is closely related to the occurrence and development of cardiovascular diseases (CVDs). As an early marker of the development of a series of vascular diseases, endothelial dysfunction is often accompanied by oxidative stress and inflammatory response. Natural flavonoids in fruits, vegetables, and Chinese herbal medicines have been shown to induce and regulate endothelial cells and exert anti-inflammatory, anti-oxidative stress, and anti-aging effects in a large number of in vitro models and in vivo experiments so as to achieve the prevention and improvement of cardiovascular disease. Focusing on endothelial mediation, this paper introduces the signaling pathways involved in the improvement of endothelial dysfunction by common dietary and flavonoids in traditional Chinese medicine and describes them based on their metabolism in the human body and their relationship with the intestinal flora. The aim of this paper is to demonstrate the broad pharmacological activity and target development potential of flavonoids as food supplements and drug components in regulating endothelial function and thus in the prevention and treatment of cardiovascular diseases. This paper also introduces the application of some new nanoparticle carriers in order to improve their bioavailability in the human body and play a broader role in vascular protection.

Zanthoxylum bungeanum as a natural pickling spice alleviates health risks in animal-derived foods via up-regulating glutathione S-transferase, down-regulating cytochrome P450 1A

Endogenous aflatoxin B1 (AFB1) was quantified in five hundred and forty Hengshan goat meat samples (0.00 ± 23.09 μg kg^-1). Zanthoxylum bungeanum (Z. bungeanum), as a natural pickling spice, can ameliorate the flavor of animal-derived food (goat meat). Yet, considering the direct administration of Z. bungeanum in AFB1-contaminated goat meat, the degradation mechanisms of AFB1 remain elusive. Here, UHPLC-Q-Orbitrap HRMS-based integrative metabolomics (LOQ: 1.74-59.54 μg kg^-1) and proteomics analyses were executed to determine the effects of Z. bungeanum in the biotransformation of AFB1. Z. bungeanum (1.50 %, w/w) application mediated the metabolism of xenobiotics by cytochrome P450, significantly down-regulated cytochrome P450 1A and stimulated the up-regulation of glutathione S-transferase levels in AFB1-contaminated goat meat, leading to degradation of AFB1 (20.00-3.39 μg kg^-1). Metabolomics assays indicated that Z. bungeanum up-regulated l-histidine (1.43-2.21 mg kg^-1) and l-arginine, manifesting potential applications for the contribution of Z. bungeanum to the nutritional value of goat meat.

Flavonoids as G Protein-coupled Receptors Ligands: New Potential Therapeutic Natural Drugs

G protein coupled receptors (GPCRs) are among the largest family of cell surface receptors found in the human genome. They govern a wide range of physiological responses in both health and diseases, making them one of the potential targeted surface receptors for pharmaceuticals. Flavonoids can modulate GPCRs activity by acting as allosteric ligands. They can either enhance or reduce the GPCR's effect. Emerging research shows that individual flavonoids or mixtures of flavonoids from plant extracts can have relevant pharmacological effects against a number of diseases, particularly by influencing GPCRs. In the present review, we are considering to give a comprehensive overview of flavonoids and related compounds that exhibit GPCRs activity and to further explore which beneficial structural features. Molecular docking was used to strengthen experimental evidence and describe flavonoid-GPCRs interactions at molecular level.