Blood-Pressure-Lowering and Endothelium-Dependent Vasorelaxant Effects of Nutgall Tree in Rats.

Hypertension is the crucial modifiable risk factor for cardiovascular diseases, and efforts to identify functional foods that are effective for hypertension control are increasing. The nutgall tree (NT, Rhus chinensis Mill.) is used in traditional medicine and food because of its medicinal value. However, the role of NT in hypertension has not been investigated. Therefore, the hypotensive effect of NT leaf ethanol extract (NTE) was investigated in spontaneously hypertensive rats (SHRs). SHRs were allocated to three groups (control, 300, or 1000 mg/kg NTE), and blood pressure was measured before and after oral administration. Systolic and diastolic blood pressure significantly decreased in the NTE 1000 mg/kg group and was the lowest at 2 h after administration (-26.4 ± 10.3, -33.5 ± 9.8%, respectively). Daily NTE administration for five days also resulted in a similar effect. Further, the vasorelaxant effects and related mechanisms were investigated in the aortas of Sprague Dawley rats. NTE showed the dose-dependent blood-vessel-relaxing effect, and its mechanism involves the NO-sGC-cGMP pathway, activation of K+ channels, and reduction in the vasoconstrictive action of angiotensin II. Therefore, our study provides basic data indicating the potential use of NTE as a functional food for high blood pressure.

Gooderoside A from Anoectochilus elatus attenuates acute and chronic pains by inhibiting NO/cGMP and IRAK4/IRAK1/TAK1 signaling pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: Anoectochilus elatus Lindl. was traditionally used for pain treatment and Gooderoside A (GA) was regarded as its principal constituent. AIM OF THE STUDY: To investigate whether GA can be responsible for the antinociceptive activity of A. elatus and explore its underlying mechanism. MATERIALS AND METHODS: Acetic acid-induced abdominal writhing and tail flick tests were employed to evaluate the antinociceptive activity of ethanolic extract of A. elatus (EEA) and GA. Formalin test was used to ascertain the antinociceptive pattern of GA. Entobarbital sodium induced sleep test was adopted to exclude its hypnotic effect, while open-field test was performed to rule out its motor impairment effect. Chronic constriction injury (CCI)-induced neuropathic pain in rats was developed to evaluate its efficacy on neuropathic pain, and BV-2 cells were used to explore the underlying mechanism. RESULTS: EEA and GA, significantly inhibited chemical and thermal nociception. GA suppressed nociception in formalin test in both phase I and II, whereas methylene blue and L-NAME partially reversed its efficacy. GA located inner and slightly blocked sodium channel current, and did not show any hypnotic effect or motor impairment effect. Crucially, GA markedly attenuated chronic neuropathic pain in rats, inhibited the phosphorylation of IRAK4, IRAK1 and TAK1, and suppressed MAPKs pathway in BV-2 cells. CONCLUSION: GA relieved acute and chronic pains in vivo. The mechanism of action involves the blocking of NO/cGMP and IRAK4/IRAK1/TAK1 pathways. These results suggested GA may be a promising candidate for antinociceptive drug development.

Hypotensive and Vasorelaxant Effects of Sanguisorbae Radix Ethanol Extract in Spontaneously Hypertensive and Sprague Dawley Rats.

Hypertension requires proper management because of the increased risk of cardiovascular disease and death. For this purpose, functional foods containing tannins have been considered an effective treatment. Sanguisorbae radix (SR) also contains various tannins; however, there have been no studies on its vasorelaxant or antihypertensive effects. In this study, the vasorelaxant effect of the ethanol extract of SR (SRE) was investigated in the thoracic aorta of Sprague Dawley rats. SRE (1, 3, 10, 30, and 100 µg/mL) showed this effect in a dose-dependent manner, and its mechanisms were related to the NO/cGMP pathway and voltage-gated K+ channels. Concentrations of 300 and 1000 µg/mL blocked the influx of extracellular Ca2+ and inhibited vasoconstriction. Moreover, 100 µg/mL of SRE showed a relaxing effect on blood vessels constricted by angiotensin II. The hypotensive effect of SRE was investigated in spontaneously hypertensive rats (SHR) using the tail-cuff method. Blood pressure significantly decreased 4 and 8 h after 1000 mg/kg of SRE administration. Considering these hypotensive effects and the vasorelaxant mechanisms of SRE, our findings suggests that SRE can be used as a functional food to prevent and treat hypertension. Further studies are needed for identifying the active components and determining the optimal dosage.

Modulation of the nitric oxide/cGMP pathway in cardiac contraction and relaxation: Potential role in heart failure treatment.

Evidence exists that heart failure (HF) has an overall impact of 1-2 % in the global population being often associated with comorbidities that contribute to increased disease prevalence, hospitalization, and mortality. Recent advances in pharmacological approaches have significantly improved clinical outcomes for patients with vascular injury and HF. Nevertheless, there remains an unmet need to clarify the crucial role of nitric oxide/cyclic guanosine 3',5'-monophosphate (NO/cGMP) signalling in cardiac contraction and relaxation, to better identify the key mechanisms involved in the pathophysiology of myocardial dysfunction both with reduced (HFrEF) as well as preserved ejection fraction (HFpEF). Indeed, NO signalling plays a crucial role in cardiovascular homeostasis and its dysregulation induces a significant increase in oxidative and nitrosative stress, producing anatomical and physiological cardiac alterations that can lead to heart failure. The present review aims to examine the molecular mechanisms involved in the bioavailability of NO and its modulation of downstream pathways. In particular, we focus on the main therapeutic targets and emphasize the recent evidence of preclinical and clinical studies, describing the different emerging therapeutic strategies developed to counteract NO impaired signalling and cardiovascular disease (CVD) development.

Cucurbitacin C suppresses the progression of pancreatic ductal adenocarcinoma via inhibition of the cGMP-PKG-VASP axis.

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most devastating diseases; it has a considerably poor prognosis and may become the second most lethal malignancy in the next 10 years. Chemotherapeutic resistance is common in PDAC; thus, it is necessary to exploit effective alternative drugs. In recent years, traditional folk medicines and their extracts have shown great potential in cancer treatment. The seed of Lagenaria siceraria (Molina) Standl. is a traditional medicine in Asia. Because of its analgesic effects and ability to reduce swelling, it is often used as an adjuvant treatment for abdominal tumors. Cucurbitacin compounds are extracts abundant in Lagenaria siceraria (Molina) Standl. Here, we found that cucurbitacin C (CuC), a member of the cucurbitacin family, has apparent anti-PDAC therapeutic properties. CuC decreased the viability and suppressed the proliferation of PDAC cells in a time- and dose-dependent manner. Further studies revealed that CuC inhibited cell migration and invasion by inhibiting epithelial-mesenchymal transition (EMT). In addition, G2/M arrest was induced, and the apoptotic pathway was activated. Transcriptomic and bioinformatic analyses showed that CuC inhibited the cGMP-PKG-VASP axis, increasing the content of cGMP to restore tumor characteristics. The antitumor activity of CuC in vivo was verified through animal experiments, and no obvious side effects were observed. Overall, our study indicates a candidate therapeutic compound for PDAC that is worthy of further development.

p-Synephrine Indicates Internal Maturity of Citrus grandis (L.) Osbeck cv. Mato Peiyu-Reclaiming Functional Constituents from Nonedible Parts.

The processing of Citrus grandis Osbeck cv. Mato Peiyu (CGMP) fruits generates a considerable amount of waste, mainly the flavedo, albedo, and segment membrane; the generated waste yields severe environmental and economic challenges. In this study, we tried to reclaim some functional chemicals from the waste. Our data indicated that the essential oil content in the flavedo was 0.76-1.34%, with the major component being monoterpenes (93.75% in August, declining to 85.56% in November, including mainly limonene (87.08% to 81.12%) and others such as ß-myrcene). p-Synephrine (mg/100 g dry weight) declined accordingly (flavedo, 10.40 to 2.00; albedo, 1.80 to 0.25; segment membrane, 0.3 in August, 0.2 in September, and none since October). Polyphenols (in µg/g) included gallic acid (70.32-110.25, 99.27-252.89, and 105.78-187.36, respectively); protocatechuic acid (65.32-204.94, 26.35-72.35, and 214.98-302.65, respectively), p-coumaric acid (30.63-169.13, 4.32-17.00, and 6.68-34.32, respectively), ferulic acid (12.36-39.36, 1.21-10.25, and 17.07-39.63, respectively), and chlorogenic acid (59.19-199.36, 33.08-108.57, and 65.32-150.14, respectively). Flavonoids (in µg/g) included naringin (flavedo, 89.32-283.19), quercetin (181.05-248.51), nobiletin (259.75-563.7), hesperidin, and diosmin. The phytosterol content (mg/100 g) was 12.50-44.00 in the flavedo. The total dietary fiber in the segment membrane was 57 g/100 g. The antioxidant activity against the DPPH• and ABTS+• free radicals was moderately high. In conclusion, the waste of CGMP fruits is worth reclaiming for essential oil, p-synephrine, polyphenolics, and dietary fiber. Notably, p-synephrine content (flavedo: <8 mg/100 g dry weight, albedo: <2.0, or segment membrane: <0.4 mg) can serve as a marker of the internal maturation of CGMP fruits.

Functional Axis of PDE5/cGMP Mediates Timosaponin-AIII-Elicited Growth Suppression of Glioblastoma U87MG Cells.

Glioblastoma (GBM) is the most aggressive brain tumor, with high mortality. Timosaponin AIII (TIA), a steroidal saponin isolated from the medicinal plant Anemarrhena asphodeloides Bge., has been shown to possess anticancer properties in various cancer types. However, the effect of TIA on GBM is unknown. In this study, we reveal that TIA not only inhibited U87MG in vitro cell growth but also in vivo tumor development. Moreover, we found that the cause of TIA-induced cell growth suppression was apoptosis. When seeking to uncover antitumor mechanisms of TIA, we found that TIA diminished the expression of cGMP-specific phosphodiesterase 5(PDE5) while elevating the levels of guanylate cyclases (sGCß), cellular cGMP, and phosphorylation of VASPser239. Following the knockdown of PDE5, PDE5 inhibitor tadalafil and cGMP analog 8-Bro-cGMP both inhibited cell growth and inactivated ß-catenin; we reason that TIA elicited an antitumor effect by suppressing PDE5, leading to the activation of the cGMP signaling pathway, which, in turn, impeded ß-catenin expression. As ß-catenin is key for cell growth and survival in GBM, this study suggests that TIA elicits its anti-tumorigenic effect by interfering with ß-catenin function through the activation of a PDE5/cGMP functional axis.

Antioxidant-rich Terminalia catappa fruit exerts antihypertensive effect via modulation of angiotensin-1-converting enzyme activity and H2S/NO/cGMP signalling pathway in Wistar rats.

INTRODUCTION: The present study aimed at investigating the effect of Terminalia catappa fruits on blood pressure, NO/cGMP signalling pathway, angiotensin-1-converting enzyme and arginase activity, and oxidative stress biomarkers in L-NAME-induced hypertensive rats. MATERIALS AND METHODS: Forty-two Wistar rats were divided into seven groups. Hypertension was induced via oral administration of 40 mg/kg of L-NAME for 21 days. Thereafter, the hypertensive rats were treated with Terminalia catappa fruit-supplemented diet and sildenafil citrate for 21 days. The blood pressure was measured and cardiac homogenate was prepared for biochemical analyses. RESULTS: The results showed that L-NAME caused a significant (p < 0.05) increase in systolic and diastolic blood pressure, and heart rate as well as ACE, arginase and PDE-5 activity, with a simultaneous decrease in NO and H2S levels as well as increased oxidative stress biomarkers. However, treatment with Terminalia catappa fruits-supplemented diets and sildenafil citrate lowered blood pressure and modulated ACE, arginase, and PDE-5 activity, improved NO and H2S levels, as well as antioxidant status. CONCLUSION: Findings presented in this study provide useful information on the antihypertensive property of Terminalia catappa fruits, alongside some possible mechanisms. Hence, Terminalia catappa fruits could be considered a dietary regimen and functional food in alleviating hypertension.

Hawthorn leaves flavonoids attenuate cardiac remodeling induced by simulated microgravity.

CONTEXT: Hawthorn leaves are a kind of widely used medicinal plant in China. The major ingredient, hawthorn leaves flavonoids (HLF), have cardiotonic, cardioprotective, and vascular protective effects. OBJECTIVE: The study evaluated the protective role of HLF in cardiac remodelling and the underlying mechanisms under simulated microgravity by hindlimb unloading rats. MATERIALS AND METHODS: Adult male Sprague-Dawley rats were divided into control, HLF, HU (hindlimb unloading) and HU + HLF groups (n = 8). After HU and daily intragastric administration at the dose of 100 mg/kg/d for 8 weeks, cardiac function and structure were evaluated by biochemical indices and histopathology. We identified the main active compounds and mechanisms involved in the cardioprotective effects of HLF via bioinformatics and molecular docking analysis, and relative signalling pathway activity was verified by Western blot. RESULTS: HLF treatment could reverse the HU-induced decline in LV-EF (HU, 55.13% ± 0.98% vs. HU + HLF, 71.16% ± 5.08%), LV-FS (HU, 29.44% ± 0.67% vs. HU + HLF, 41.62% ± 4.34%) and LV mass (HU, 667.99 ± 65.69 mg vs. HU + HLF, 840.02 ± 73.00 mg). Furthermore, HLF treatment significantly increased NPRA expression by 135.39%, PKG by 51.27%, decreased PDE5A by 20.03%, NFATc1 by 41.68% and Rcan1.4 by 54.22%. CONCLUSIONS: HLF plays a protective effect on HU-induced cardiac remodelling by enhancing NPRA-cGMP-PKG pathway and suppressing the calcineurin-NFAT pathway, which provides a theoretical basis for use in clinical therapies.

Low-Protein Formulas with Alpha-Lactalbumin-Enriched or Glycomacropeptide-Reduced Whey: Effects on Growth, Nutrient Intake and Protein Metabolism during Early Infancy: A Randomized, Double-Blinded Controlled Trial.

Protein intake is higher in formula-fed than in breast-fed infants during infancy, which may lead to an increased risk of being overweight. Applying alpha-lactalbumin (α-lac)-enriched whey or casein glycomacropeptide (CGMP)-reduced whey to infant formula may enable further reduction of formula protein by improving the amino acid profile. Growth, nutrient intake, and protein metabolites were evaluated in a randomized, prospective, double-blinded intervention trial where term infants received standard formula (SF:2.2 g protein/100 kcal; n = 83) or low-protein formulas with α-lac-enriched whey (α-lac-EW;1.75 g protein/100 kcal; n = 82) or CGMP-reduced whey (CGMP-RW;1.76 g protein/100 kcal; n = 80) from 2 to 6 months. Breast-fed infants (BF; n = 83) served as reference. Except between 4 and 6 months, when weight gain did not differ between α-lac-EW and BF (p = 0.16), weight gain was higher in all formula groups compared to BF. Blood urea nitrogen did not differ between low-protein formula groups and BF during intervention, but was lower than in SF. Essential amino acids were similar or higher in α-lac-EW and CGMP-RW compared to BF. Conclusion: Low-protein formulas enriched with α-lac-enriched or CGMP-reduced whey supports adequate growth, with more similar weight gain in α-lac-enriched formula group and BF, and with metabolic profiles closer to that of BF infants.

Sambucus williamsii Hance maintains bone homeostasis in hyperglycemia-induced osteopenia by reversing oxidative stress via cGMP/PKG signal transduction.

BACKGROUND: Sambucus williamsii Hance (SWH) has effectively been adopted to treat joint and bone disorders. Diabetes-induced osteopenia (DOP) is caused primarily by impaired bone formation as a result of hyperglycemia. We had previously demonstrated that SWH extract accelerated fracture healing and promoted osteoblastic MC3T3-E1 cell proliferation and osteogenic differentiation. This study assessed the impacts of SWH extract on diabetes-induced bone loss and explored the mechanisms underlying its osteoprotective effects. METHODS: This work employed MC3T3-E1 cell line for evaluating how SWH extract affected osteogenesis, oxidative stress (OS), and the underlying mechanism in vitro. Streptozotocin-induced osteopenia mouse model was applied with the purpose of assessing SWH extract's osteoprotection on bone homeostasis in vivo. RESULTS: The increased OS of MC3T3-E1 cells exposed to high glucose (HG) was largely because of the upregulation of pro-oxidant genes and the downregulation of antioxidant genes, whereas SWH extract reduced the OS by modulating NADPH oxidase-4 and thioredoxin-related genes by activating cyclic guanosine monophosphate (cGMP) production and increasing the level of cGMP-mediated protein kinase G type-2 (PKG2). The oral administration of SWH extract maintained bone homeostasis in type 1 diabetes mellitus (T1DM) mice by enhancing osteogenesis while decreasing OS. In bones from hyperglycemia-induced osteopenia mice and HG-treated MC3T3-E1 cells, the SWH extract achieved the osteoprotective effects through activating the cGMP/PKG2 signaling pathway, upregulating the level of antioxidant genes, as well as downregulating the level of pro-oxidant genes. CONCLUSION: SWH extract exerts osteoprotective effects on hyperglycemia-induced osteopenia by reversing OS via cGMP/PKG signal transduction and is a potential therapy for DOP.

Zhenwu decoction ameliorates cardiac hypertrophy through activating sGC (soluble guanylate cyclase) - cGMP (cyclic guanosine monophosphate) - PKG (protein kinase G) pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Zhenwu Decoction (ZWD) is a traditional Chinese medicine (TCM) formula which has wide scope of indications related to Yang deficiency and dampness retention in TCM syndrome. Cardiac hypertrophy can induce similar symptoms and signs to the clinical features of Yang deficiency and dampness retention syndrome. ZWD can increase the left ventricular ejection fraction, reduce cardiac hypertrophy of patients with chronic heart failure. However, its underlying pharmacological mechanism remains unclear. AIM OF THE STUDY: The study aimed to confirm the protective effects of ZWD on cardiac hypertrophy and explore the underlying mechanisms. MATERIALS AND METHODS: The potential targets and pathways of ZWD in cardiac hypertrophy were highlighted by network pharmacology and validated by mechanistic and functional studies. RESULTS: Our network pharmacology analysis suggests that the protective effects of ZWD on cardiac hypertrophy are related to cyclic guanosine monophosphate (cGMP) - protein kinase G (PKG) pathway. Subsequent animal studies showed that ZWD significantly ameliorated cardiac function decline, cardiac hypertrophy, cardiac fibrosis and cardiomyocyte apoptosis. To explore the underlying mechanisms of action, we performed Western blotting, immunohistochemical analysis, and detection of inflammatory response and oxidative stress. Our results showed that ZWD activated the soluble guanylate cyclase (sGC) - cGMP - PKG signaling pathway. The sGC inhibitor ODQ that blocks the sGC-cGMP-PKG signaling pathway in zebrafish abolished the protective effects of ZWD, suggesting sGC-cGMP-PKG is the main signaling pathway mediates the protective effect of ZWD in cardiac hypertrophy. In addition, three major ingredients from ZWD, poricoic acid C, hederagenin and dehydrotumulosic acid, showed a high binding energy with prototype sGC. CONCLUSION: ZWD reduces oxidative stress and inflammation and exerts cardioprotective effects by activating the sGC-cGMP-PKG signaling pathway.

Pharmacological mechanism and therapeutic efficacy of Icariside II in the treatment of acute ischemic stroke: a systematic review and network pharmacological analysis.

BACKGROUND AND OBJECTIVE: Epimedii has long been used as a traditional medicine in Asia for the treatment of various common diseases, including Alzheimer's disease, cancer, erectile dysfunction, and stroke. Studies have reported the ameliorative effects of Icariside II (ICS II), a major metabolite of Epimedii, on acute ischemic stroke (AIS) in animal models. Based on network pharmacology, molecular docking, and molecular dynamics (MD) simulations, we conducted a systematic review to evaluate the effects and neuroprotective mechanisms of ICS II on AIS. METHODS: First, we have searched 6 databases using studies with ICS II treatment on AIS animal models to explore the efficacy of ICS II on AIS in preclinical studies. The literature retrieval time ended on March 8, 2022 (Systematic Review Registration ID: CRD42022306291). There were no restrictions on the language of the search strategy. Systematic review follows the Patient, Intervention, Comparison and Outcome (PICO) methodology and framework. SYCLE's RoB tool was used to evaluate the the risk of bias. In network pharmacology, AIS-related genes were identified and the target-pathway network was constructed. Then, these targets were used in the enrichments of Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways and gene ontology (GO). Molecular docking and MD simulation were finally employed between ICS II and the potential target genes. RESULTS: Twelve publications were included describing outcomes of 1993 animals. The literature details, animal strains, induction models, doses administered, duration of administration, and outcome measures were extracted from the 12 included studies. ICS II has a good protective effect against AIS. Most of the studies in this systematic review had the appropriate methodological quality, but some did not clearly state the controlling for bias of potential study. Network pharmacology identified 246 targets with SRC, CTNNB1, HSP90AA1, MAPK1, and RELA as the core target proteins. Besides, 215 potential pathways of ICS II were identified, such as PI3K-Akt, MAPK, and cGMP-PKG signaling pathway. GO enrichment analysis showed that ICS II was significantly enriched in subsequent regulation such as MAPK cascade. Molecular docking and MD simulations showed that ICS II can closely bind with important targets. CONCLUSIONS: ICS II is a promising drug in the treatment of AIS. However, this systematic review reveals key knowledge gaps (i.e., the protective role of ICS II in women) that ICS II must address before it can be used for the treatment of human AIS. Our study shows that ICS II plays a protective role in AIS through multi-target and multi-pathway characteristics, providing ideas for the development of drugs for the treatment of AIS.

67-kDa Laminin Receptor-Mediated Cellular Sensing System of Green Tea Polyphenol EGCG and Functional Food Pairing.

The body is equipped with a "food factor-sensing system" that senses food factors, such as polyphenols, sulfur-containing compounds, and vitamins, taken into the body, and plays an essential role in manifesting their physiological effects. For example, (-)-epigallocatechin-3-O-gallate (EGCG), the representative catechin in green tea (Camellia sinensi L.), exerts various effects, including anti-cancer, anti-inflammatory, and anti-allergic effects, when sensed by the cell surficial protein 67-kDa laminin receptor (67LR). Here, we focus on three representative effects of EGCG and provide their specific signaling mechanisms, the 67LR-mediated EGCG-sensing systems. Various components present in foods, such as eriodictyol, hesperetin, sulfide, vitamin A, and fatty acids, have been found to act on the food factor-sensing system and affect the functionality of other foods/food factors, such as green tea extract, EGCG, or its O-methylated derivative at different experimental levels, i.e., in vitro, animal models, and/or clinical trials. These phenomena are observed by increasing or decreasing the activity or expression of EGCG-sensing-related molecules. Such functional interaction between food factors is called "functional food pairing". In this review, we introduce examples of functional food pairings using EGCG.

Fustin, a Flavanonol, Synergically Potentiates the Anticancer Effect of Green Tea Catechin Epigallocatechin-3-O-Gallate with Activation of the eNOS/cGMP Axis.

Epigallocatechin-3-O-gallate (EGCG), a catechin present in green tea, selectively elicits apoptosis in multiple myeloma cells by activating the endothelial nitric oxide synthase (eNOS)/cyclic guanosine monophosphate (cGMP) axis. However, the effects of EGCG alone are limited. Herein, we revealed that fustin, a flavanonol, enhances the EGCG-elicited activation of the cGMP/eNOS axis in multiple myeloma cells. Isobologram analysis demonstrated that EGCG/fustin synergistically elicited cell death in multiple myeloma cells. Importantly, this chemical combination significantly promoted cell death without affecting the normal cells. To assess the effects of EGCG and fustin in vivo, female BALB/c mice were inoculated with multiple myeloma MPC11 cells and then treated with each compound. The combination of EGCG/fustin suppressed tumor growth in vivo without affecting alanine aminotransferase/aspartate aminotransferase levels, the dose-limiting toxicity of EGCG. Consistent with in vitro findings, this combination increased eNOS phosphorylation at Ser1177 in the tumor. Collectively, fustin amplified EGCG-induced activation of the eNOS/cGMP axis.

Subcellular Localization of Homomeric TASK3 Channels and Its Presumed Functional Significances in Trigeminal Motoneurons.

Somatic expressions of either heteromeric TASK1/3 or homomeric TASK1/1 channels have been reported in various neurons, while expression of homomeric TASK3/3 channels has been re-ported only in dendrites. However, it is not known why homomeric TASK3/3 channels are hardly seen in somata of CNS neurons. Given the absence of somatic TASK3/3 channels, it should be clarified why dendritic expression of TASK3/3 channels is inevitable and necessary and how differentially distributed TASK1/1 and TASK3/3 channels play roles in soma-to-dendritic integration. Here, we addressed these questions. We found that TASK3-transfected HEK293 cells showed decreases in cell volume after being transferred from the cultured medium to HEPES Ringer, suggesting that expressions of TASK3 channels in cell bodies cause an osmolarity problem. Using TASK1- and TASK3-transfected oocytes, we also found that cGMP application slightly suppressed TASK3 currents while it largely enhanced TASK1 currents, alleviating the difference between TASK1 and TASK3 currents at physiological pH. As larger motoneurons have extensive dendritic trees while smaller motoneurons have poor ones, cGMP could integrate Ia-EPSPs to recruit small and large motoneurons synchronously by differentially modulating TASKI and TASK3 channels which were complementary distributed in soma and dendrites of motoneurons in the dorsolateral part of the trigeminal motor nucleus.

Ziziphus Oxyphylla hydro-methanolic extract ameliorates hypertension in L-NAME induced hypertensive rats through NO/cGMP pathway and suppression of oxidative stress related inflammatory biomarkers.

ETHNOPHARMACOLOGICAL RELEVANCE: Ziziphus Oxyphylla belongs to family Ziziphus and has been used traditionally in hypertension. It is enriched with quercetin and kaempferol derivatives, catechin and cyclopeptide alkaloids. AIM: The current research evaluates the antihypertensive potential of aqueous methanolic extract of Z. oxyphylla (AMEZO) in NG-nitro-L-arginine methyl ester (LNAME) induced hypertension in rats. MATERIAL AND METHODOLOGY: Phytochemical analysis of AMEZO was carried out using high performance liquid chromatography (HPLC) and electrospray ionization mass spectrometry (ESI-MS/MS). Antihypertensive activities of AMEZO (200 and 400 mg/kg) and Kaempferol were assessed in L-NAME (185 µmol/kg, intraperitoneal) injected hypertensive rats. In normotensive rats, blood pressure was assessed using Power Lab data system. Serum and tissue samples were preserved for estimation of nitric oxide (NO), Cyclic guanosine monophosphate (cGMP), interleukin-6 (IL-6), tumor necrosis factor (TNF- α) and oxidative stress markers respectively. mRNA levels of eNOS, ACE, COX-2 and NF-kB genes were assessed through qPCR. RESULTS: The HPLC and ESI-MS/MS identified kaempferol, quercetin, catechin, ceanothic acid, zizybernalic acid and oxyphylline F. Chronic administration of AMEZO and kaempferol in L-NAME induced hypertensive rats significantly (p < 0.001) reduced systolic, diastolic and mean blood pressure. AMEZO and kaempferol caused meaningfully improved (p < 0.001) serum NO and cGMP levels. AMEZO administration also noticeably decrease the elevated IL-6 and TNF- α concentration in hypertensive animals. Administration of AMEZO and kaempferol also improved oxidative stress markers (MDA, CAT, SOD, GSH). The antihypertensive activity of AMEZO also resulted in upregulation of eNOS and downregulation of ACE. CONCLUSION: These data depict that AMEZO and kaempferol showed antihypertensive activity in LNAME induced hypertensive rats possibly mediated through improvement in NO and cGMP levels, modulation of mRNA expression of eNOS, ACE, COX-2 and NF-kB and suppression of oxidative stress related inflammatory markers, proposing a defensive role in cardiovascular diseases.

Luteolin attenuates lipopolysaccharide-induced acute lung injury/acute respiratory distress syndrome by activating alveolar epithelial sodium channels via cGMP/PI3K pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Luteolin (Lut) was recently identified as the major active ingredient of Mosla scabra, which was a typical representative traditional Chinese medicine and had been used to treat pulmonary diseases for thousands of years. AIM OF THE STUDY: This study was to explore the effects and relative mechanisms of Lut in LPS-induced acute lung injury/acute respiratory distress syndrome (ALI/ARDS). The main characteristic of ALI/ARDS is pulmonary edema, and epithelial sodium channel (ENaC) is a key factor in effective removal of excessive alveolar edematous fluid, which is essential for repairing gas exchange and minimizing damage to the peripheral tissues. However, whether the therapeutic effects of Lut on respiratory diseases are relative with ENaC is still unknown. MATERIALS AND METHODS: Alveolar fluid clearance was calculated in BALB/c mice and ENaC function was measured in H441 cells. Moreover, ENaC membrane protein and mRNA were detected by Western blot and real-time PCR, respectively. We also studied the involvement of cGMP/PI3K pathway during the regulation of Lut on ENaC during LPS-induced ALI/ARDS by ELISA method and applying cGMP/PI3K inhibitors/siRNA. RESULTS: The beneficial effects of Lut in ALI/ARDS were evidenced by the alleviation of pulmonary edema, and enhancement of both amiloride-sensitive alveolar fluid clearance and short-circuit currents. Lut could alleviate the LPS decreased expression levels of ENaC mRNA and membrane protein in H441 cells and mouse lung. In addition, cGMP concentration was increased after the administration of Lut in ALI/ARDS mice, while the inhibition of cGMP/PI3K pathway could abrogate the enhanced AFC and ENaC protein expression of Lut. CONCLUSION: These results implied that Lut could attenuate pulmonary edema via enhancing the abundance of membrane ENaC at least partially through the cGMP/PI3K pathway, which could provide a promising therapeutic strategy for treating ALI/ARDS.

Natural Molecules as Talented Inhibitors of Nucleotide Pyrophosphatases/ Phosphodiesterases (PDEs).

BACKGROUND: Phosphodiesterases (PDEs) are a wide group of enzymes with multiple therapeutic actions, including vasorelaxation, cardiotonic, antidepressant, anti-inflammatory, antithrombotic, anti-spasmolytic, memory-enhancing, and anti-asthmatic. PDEs with eleven subtypes from PDE-1 to PDE-11 typically catalyze the cleavage of the phosphodiester bond and, hence, degrades either cyclic adenosine monophosphate (cAMP) or cyclic guanosine monophosphate (cGMP). OBJECTIVE: Several selective or non-selective inhibitors of the PDE subtypes are used clinically, i.e. sildenafil, rolipram, cysteine, etc. Recently, interest in plant-based pharmacologically bioactive compounds having potent PDEs inhibitory potential has increased. Purposely, extensive research has been carried out on natural products to explore new inhibitors of various PDEs. Therefore, this review summarizes the published data on natural PDEs inhibitors and their potential therapeutic applications. METHODS: For this purpose, natural compounds with PDE inhibitory potential have been surveyed through several databases, including PubMed, Web of Sciences (WoS), Scopus, and Google Scholar. RESULTS: According to a detailed literature survey, the most promising class of herbal compounds with PDE-inhibiting property has been found to belong to phenolics, including flavonoids (luteolin, kaempferol, icariin, etc.). Many other encouraging inhibitors from plants have also been identified, such as coumarins (23, 24) (licoarylcoumarin and glycocoumarin,), saponins (agapanthussaponins), lignans (31, 33) [(±)-schizandrin and kobusin], terpenes (28, 29, 31) (perianradulcin A, quinovic acid, and ursolic acid), anthraquinones (18, 19) (emodin and chrysophanol), and alkaloids (Sanjoinine-D) (36). CONCLUSION: In this review, studies have revealed the PDE-inhibitory potential of natural plant extracts and their bioactive constituents in treating various diseases; however, further clinical studies comprising synergistic use of different therapies (synthetic & natural) to acquire multi-targeted results might also be a promising option.

UHPLC-MS/MS analysis of cAMP and cGMP in rat plasma as potential biomarkers of Yin-Yang disharmony in traditional Chinese medicine.

Cyclic 3',5'-adenosine monophosphate (cAMP) and cyclic 3',5'-guanosine monophosphate (cGMP) are considered as potential biomarkers for Yin-Yang disharmony in traditional Chinese medicine. However, phosphodiesterase-mediated ex vivo degradation of these molecules in biological samples may result in their underestimation. In the present study, a ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed for determination of cAMP and cGMP in rat plasma, with special consideration of their stability ex vivo. Following precipitation of proteins from plasma samples with 0.4 M perchloric acid, the analytes were chromatographed on a Shimadzu Shim-pack-XR-ODS II column with 2.5 mM ammonium acetate and methanol in gradient mode. The MS/MS detection was performed using multiple reaction monitoring in the positive electrospray ionization mode. The lower limit of quantification was 0.27 ng/mL for cAMP and 0.37 ng/mL for cGMP. The method was used to determine the plasma cAMP and cGMP levels in normal and Yin deficiency diabetic rats treated with or without Rehmannia glutinosa. The developed method may be useful for evaluating the regulatory effects of Chinese herbal medicine on the levels of cAMP and cGMP in the body.