Artemisia argyi extracts overcome lapatinib resistance via enhancing TMPRSS2 activation in HER2-positive breast cancer.

Breast cancer stands as the predominant malignancy and primary cause of cancer-related mortality among females globally. Approximately 25% of breast cancers exhibit HER2 overexpression, imparting a more aggressive tumor phenotype and correlating with poor prognoses. Patients with metastatic breast cancer receiving HER2 tyrosine kinase inhibitors (HER2 TKIs), such as Lapatinib, develop acquired resistance within a year, posing a critical challenge in managing this disease. Here, we explore the potential of Artemisia argyi, a Chinese herbal medicine known for its anti-cancer properties, in mitigating HER2 TKI resistance in breast cancer. Analysis of the Cancer Genome Atlas (TCGA) revealed diminished expression of transmembrane serine protease 2 (TMPRSS2), a subfamily of membrane proteolytic enzymes, in breast cancer patients, correlating with unfavorable outcomes. Intriguingly, lapatinib-responsive patients exhibited higher TMPRSS2 expression. Our study unveiled that the compounds from Artemisia argyi, eriodictyol, and umbelliferone could inhibit the growth of lapatinib-resistant HER2-positive breast cancer cells. Mechanistically, they suppressed HER2 kinase activation by enhancing TMPRSS2 activity. Our findings propose TMPRSS2 as a critical determinant in lapatinib sensitivity, and Artemisia argyi emerges as a potential agent to overcome lapatinib via activating TMPRSS2 in HER2-positive breast cancer. This study not only unravels the molecular mechanisms driving cell death in HER2-positive breast cancer cells induced by Artemisia argyi but also lays the groundwork for developing novel inhibitors to enhance therapy outcomes.

Eriodictyol attenuates doxorubicin-induced nephropathy by activating the AMPK/Nrf2 signalling pathway.

Doxorubicin (DOX), an anthracycline chemotherapy, plays a prominent role in the treatment of various cancers. Unfortunately, its nephrotoxic effects limit its dosing and expose cancer survivors to increased morbidity and mortality. This study examined the nephroprotective effects of eriodictyol, a natural polyphenolic flavanone, in DOX-treated rats and the molecular pathways involved. Forty adult rats were divided into five groups (8/group): Control; eriodictyol (20 mg/kg/day); DOX (2.5 mg/kg, twice/week); DOX + Eriodictyol; and DOX + Eriodictyol + Compound C (CC), an AMPK inhibitor (0.2 mg/kg/day). Experiments continued for 21 days. Eriodictyol administration in DOX-treated rats reduced their fasting glucose levels and increased food intake, final body weight, and kidney weight, improved kidney function, prevented glomerular and tubular damage, and reduced collagen deposition and renal TGF-ß1 mRNA levels. Furthermore, eriodictyol reduced their renal levels of Bax, caspase-3, and cytochrome-c; and enhanced the levels of Bcl2. Noticeably, in the kidneys of both controls and DOX-treated rats, eriodictyol increased levels of phosphorylated-AMPK(Thr172) but not AMPK mRNA nor protein levels. Also, in the same two groups, eriodictyol increased mRNA and nuclear Nrf2 levels, and levels of glutathione, superoxide dismutase, catalase, and hemeoxygenase-1, but reduced the levels of malonaldehyde, TNF-α, and mRNA, total, and nuclear levels of NF-κB. All the detected nephroprotective effects and improvements in the levels of markers of oxidation and inflammation were prevented by coadministration of CC. In conclusion, the coadministration of eriodictyol and DOX alleviates DOX-induced renal damage. In renal tissues, eriodictyol is an AMPK activator and its nephroprotective antioxidant and anti-inflammatory effects are AMPK-dependent.

Systems Metabolic Engineering of Saccharomyces cerevisiae for the High-Level Production of (2S)-Eriodictyol.

(2S)-eriodictyol (ERD) is a flavonoid widely found in citrus fruits, vegetables, and important medicinal plants with neuroprotective, cardioprotective, antidiabetic, and anti-obesity effects. However, the microbial synthesis of ERD is limited by complex metabolic pathways and often results in a low production performance. Here, we engineered Saccharomyces cerevisiae by fine-tuning the metabolism of the ERD synthesis pathway. The results showed that the ERD titer was effectively increased, and the intermediate metabolites levels were reduced. First, we successfully reconstructed the de novo synthesis pathway of p-coumaric acid in S. cerevisiae and fine-tuned the metabolic pathway using promoter engineering and terminator engineering for the high-level production of (2S)-naringenin. Subsequently, the synthesis of ERD was achieved by introducing the ThF3'H gene from Tricyrtis hirta. Finally, by multiplying the copy number of the ThF3'H gene, the production of ERD was further increased, reaching 132.08 mg L-1. Our work emphasizes the importance of regulating the metabolic balance to produce natural products in microbial cell factories.

A Comparison between High-Performance Countercurrent Chromatography and Fast-Centrifugal Partition Chromatography for a One-Step Isolation of Flavonoids from Peanut Hulls Supported by a Conductor like Screening Model for Real Solvents.

Peanut hulls (Arachis hypogaea, Leguminosae), which are a side stream of global peanut processing, are rich in bioactive flavonoids such as luteolin, eriodictyol, and 5,7-dihydroxychromone. This study aimed to isolate these flavonoid derivatives by liquid-liquid chromatography with as few steps as possible. To this end, luteolin, eriodictyol and 5,7-dihydroxychromone were isolated from peanut hulls using two different techniques, high-performance countercurrent chromatography (HPCCC) and fast-centrifugal partition chromatography (FCPC). The suitability of the biphasic solvent system composed of n-hexane/ethyl acetate/methanol/water (1.0/1.0/1.0/1.5; v/v/v/v) was determined by the Conductor like Screening Model for Real Solvents (COSMO-RS), which allowed the partition ratio KD-values of the three main flavonoids to be calculated. After a one-step HPCCC separation of ~1000 mg of an ethanolic peanut hull extract, 15 mg of luteolin and 8 mg of eriodictyol were isolated with purities over 96%. Furthermore, 3 mg of 5,7-dihydroxychromone could be isolated after purification by semi-preparative reversed-phase liquid chromatography (semi-prep. HPLC) in purity of over 99%. The compounds were identified by electrospray ionization mass spectrometry (ESI-MS) and nuclear magnetic resonance spectroscopy (NMR).

GC-MS/MS Quantification of EGFR Inhibitors, ß-Sitosterol, Betulinic Acid, (+) Eriodictyol, (+) Epipinoresinol, and Secoisolariciresinol, in Crude Extract and Ethyl Acetate Fraction of Thonningia sanguinea.

Medicinal plants are widely used in folk medicine to treat various diseases. Thonningia sanguinea Vahl is widespread in African traditional medicine, and exhibits antioxidant, antibacterial, antiviral, and anticancer activities. T. sanguinea is a source of phytomedicinal agents that have previously been isolated and structurally elucidated. Herein, gas chromatography combined with tandem mass spectrometry (GC-MS/MS) was used to quantify epipinoresinol, ß-sitosterol, eriodictyol, betulinic acid, and secoisolariciresinol contents in the methanolic crude extract and its ethyl acetate fraction for the first time. The ethyl acetate fraction was rich in epipinoresinol, eriodictyol, and secoisolariciresinol at concentrations of 2.3, 3.9, and 2.4 mg/g of dry extract, respectively. The binding interactions of these compounds with the epidermal growth factor receptor (EGFR) were computed using a molecular docking study. The results revealed that the highest binding affinities for the EGFR signaling pathway were attributed to eriodictyol and secoisolariciresinol, with good binding energies of -19.93 and -16.63 Kcal/mol, respectively. These compounds formed good interactions with the key amino acid Met 769 as the co-crystallized ligand. So, the ethyl acetate fraction of T. sanguinea is a promising adjuvant therapy in cancer treatments.

Eriodictyol inhibits breast carcinogenesis by targeting circ_0007503 and repressing PI3K/Akt pathway.

BACKGROUND: Eriodictyol in citrus fruits, Eriodictyon californicum and several Chinese herbal medicines shows great promise for chronic disease prevention, including cancers. However, its role in chemopreventive activities against breast carcinogenesis is unknown. PURPOSE: In the present study, we investigated the chemopreventive effect and the underlying mechanism of eriodictyol on carcinogens-induced breast carcinogenesis in vivo and in vitro. METHODS: The carcinogenic transformation in MCF10A cells was induced by the environmental carcinogens in vitro. The chemopreventive effect in vivo was evaluated by using the experimental model of 1-methyl-1-nitrosourea (MNU)-induced mammary tumorigenesis in rats. The activation of the PI3K/Akt pathway was detected by western blot assay; the levels of circular RNAs (circRNAs) were measured by qRT-PCR. RESULTS: First, eriodictyol significantly reduces cells viability and induces apoptosis in breast cancer cells in a dose-dependent manner in vitro (P < 0.05). Next, eriodictyol could effectively suppress environmental carcinogens-induced acquisition of carcinogenic properties in human breast epithelial cell MCF10A (P < 0.05). In vivo, eriodictyol administration reduces the incidence of mammary tumor by 50% in carcinogen-treated female rats (P < 0.05). Further study revealed that eriodictyol represses the PI3K/Akt signaling pathway and down-regulates the level of circ_0007503 in breast cancer cells and in breast carcinogenesis (P < 0.01). When the effect of eriodictyol on circ_0007503 was blocked by transfection of a circ_0007503 over-expression plasmid, the cytotoxic effects and the suppression of the PI3K/Akt pathway of eriodictyol in breast cancer cells were significantly reduced (P < 0.05). CONCLUSION: Our data indicated that eriodictyol could effectively suppress breast carcinogenesis in vitro and in vivoThe mechanism may be attributed to targeting circ_0007503 and inhibiting PI3K/Akt pathway.

Bioproduction of eriodictyol by Escherichia coli engineered co-culture.

Eriodictyol (ED) is a flavonoid in the flavanones subclass. It is abundantly present in a wide range of medicinal plants, citrus fruits, and vegetables. In addition, ED owns numerous importantly medicinal bioactivities such as inhibition of proliferation, metastasis and induction of apoptosis in glioma cells or inhibition of glioblastoma migration, and invasion. This study described the heterologous production of ED by E. coli based co-culture engineering system from the simple carbon substrate D-glucose. Two E. coli strains were engineered and functioned as constitutive components of biological system. Specifically, the first strain (upstream module) contained genes for synthesis of p-coumaric acid (pCA) from D-glucose. And, the second strain (downstream module) consisted of genes for the synthesis of ED from pCA. The highest yield in ED production was achieved 51.5 ± 0.4 mg/L using stepwise optimal culture conditions, while monoculture was achieved 21.3 ± 0.2 mg/L only. In conclusion, co-culture was the most efficient alternative approach for the synthesis of ED and other natural products.

Eriodictyol ameliorates cognitive dysfunction in APP/PS1 mice by inhibiting ferroptosis via vitamin D receptor-mediated Nrf2 activation.

BACKGROUND: Alzheimer's disease (AD) is the most common type of neurodegenerative disease in the contemporary era, and it is still clinically incurable. Eriodictyol, a natural flavonoid compound that is mainly present in citrus fruits and some Chinese herbal medicines, has been reported to exert anti-inflammatory, antioxidant, anticancer and neuroprotective effects. However, few studies have examined the anti-AD effect and molecular mechanism of eriodictyol. METHODS: APP/PS1 mice were treated with eriodictyol and the cognitive function of mice was assessed using behavioral tests. The level of amyloid-ß (Aß) aggregation and hyperphosphorylation of Tau in the mouse brain were detected by preforming a histological analysis and Western blotting. HT-22 cells induced by amyloid-ß peptide (1-42) (Aß1-42) oligomers were treated with eriodictyol, after which cell viability was determined and the production of p-Tau was tested using Western blotting. Then, the characteristics of ferroptosis, including iron aggregation, lipid peroxidation and the expression of glutathione peroxidase type 4 (GPX4), were determined both in vivo and in vitro using Fe straining, Western blotting and qPCR assays. Additionally, the expression level of vitamin D receptor (VDR) and the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) signaling pathway were tested using Western blotting and qPCR assays. Afterward, HT-22 cells with VDR knockout were used to explore the potential mechanisms, and the relationship between VDR and Nrf2 was further assessed by performing a coimmunoprecipitation assay and bioinformatics analysis. RESULTS: Eriodictyol obviously ameliorated cognitive deficits in APP/PS1 mice, and suppressed Aß aggregation and Tau phosphorylation in the brains of APP/PS1 mice. Moreover, eriodictyol inhibited Tau hyperphosphorylation and neurotoxicity in HT-22 cells induced by Aß1-42 oligomer. Furthermore, eriodictyol exerted an antiferroptosis effect both in vivo and in vitro, and its mechanism may be associated with the activation of the Nrf2/HO-1 signaling pathway. Additionally, further experiments explained that the activation of Nrf2/HO-1 signaling pathway by eriodictyol treatment mediated by VDR. CONCLUSIONS: Eriodictyol alleviated memory impairment and AD-like pathological changes by activating the Nrf2/HO-1 signaling pathway through a mechanism mediated by VDR, which provides a new possibility for the treatment of AD.

Stability of Rosmarinic Acid and Flavonoid Glycosides in Liquid Forms of Herbal Medicinal Products-A Preliminary Study.

Peppermint leaf, sage leaf, thyme herb, and their preparations are common components of herbal medicinal products (HMPs). According to the European Pharmacopoeia guidelines, the above-mentioned plant substances are standardized for the content of essential oils, omitting polyphenols, which also have a significant impact on their activities. The aim of this study was to evaluate the stability of the predominant polyphenols-rosmarinic acid, luteolin-7-O-ß-glucuronide, and eriocitrin-in selected commercial liquid HMPs containing thyme, sage, and peppermint under long-term, intermediate, and accelerated testing conditions. Qualitative and quantitative analyses of these polyphenols were performed by the previously optimized and validated HPLC-DAD method. Rosmarinic acid stability was better in hydroethanolic than in an aqueous solution. The effect of the solvent on the stability of luteolin-7-O-ß-glucuronide and eriocitrin could not be determined and requires further investigation. The present study is the first to analyze the stability of these compounds in commercial herbal medicinal products. The expiration dates proposed by the manufacturers of the tested HMPs did not guarantee stable levels of all analyzed polyphenols throughout the stated period. However, this study is preliminary and requires continuation on a larger number of medicinal products.

The pharmacological and biological roles of eriodictyol.

Eriodictyol is a flavonoid in the flavanones subclass. It is abundantly present in a wide range of medicinal plants, citrus fruits, and vegetables that are considered to have potential health importance. Having the considerable medicinal properties, eriodictyol has been predicted to clarify the mode of action in various cellular and molecular pathways. Evidence for the existing therapeutic roles of eriodictyol includes antioxidant, anti-inflammatory, anti-cancer, neuroprotective, cardioprotective, anti-diabetic, anti-obesity, hepatoprotective, and miscellaneous. Therefore, this review aims to present the recent evidence regarding the mechanisms of action of eriodictyol in different signaling pathways in a specific disease condition. In view of the immense therapeutic effects, eriodictyol may serve as a potential drug source to enhance community health standards.

Polyphenol composition and biological activity of Thymus citriodorus and Thymus vulgaris: Comparison with endemic Iberian Thymus species.

The polyphenol compositions of Thymus × citriodorus and Thymus vulgaris extracts as obtained by exhaustive hydroethanolic (HE) extraction and aqueous decoction (AD) were compared. In addition, their compositions and bioactivities were compared to those of Thymus pulegioides and Thymus mastichina, grown under the same edaphoclimatic conditions, and Thymus carnosus. Rosmarinic acid was the most abundant polyphenol followed by luteolin-hexuronide, salvianolic acids I and K. Cluster analysis suggests a similarity of the polyphenol composition of T. citriodorus and T. vulgaris. A significant antioxidant activity was observed and correlated with their polyphenol levels. The same being observed for the higher anti-proliferative activity/cytotoxicity of HE extracts on Caco-2 and HepG2 cells as compared to AD extracts. Significant association between the total phenolic compounds with the anti-proliferative activity, for both cell lines, was observed. These results support the importance of salvianolic acids levels in Thymus extracts and their in vitro anti-proliferative/cytotoxic activities.

EGCG down-regulates MuRF1 expression through 67-kDa laminin receptor and the receptor signaling is amplified by eriodictyol.

(-)-epigallocatechin-3-O-gallate (EGCG) is a bioactive polyphenol in green tea. Previous studies have demonstrated the beneficial effects of EGCG on muscle mass and muscle atrophy. In the current study, we investigated the mechanisms underlying effect of EGCG on muscle atrophy. It was demonstrated that EGCG suppressed muscle-specific ubiquitin ligase, muscle RING Finger 1 (MuRF1) expression through 67-kDa laminin receptor (67LR). Previous studies have shown that eriodictyol potentiates the anti-tumor activities of EGCG by amplifying 67LR signaling. Therefore, we investigated the effects of EGCG and eriodictyol on the MuRF1 expression in C2C12 myotubes. The combined treatment of EGCG and eriodictyol significantly suppressed MuRF1 expression in dexamethasone-treated C2C12 myotubes. Tail suspension was maintained for 10 consecutive days using C57BL6/J mice, and during this time EGCG and eriodictyol were orally administered. In the gastrocnemius muscle, the muscle mass loss was inhibited by the combination of EGCG and eriodictyol. Therefore, EGCG may prevent muscle atrophy by inducing 67LR signaling and eriodictyol amplifies this pathway.

Inhibitory Effects of Eriodictyol-7-O-ß-d-glucuronide and 5,7-Dihydroxy-4-chromene Isolated from Chrysanthemum zawadskii var. latilobum in FcεRI-Mediated Human Basophilic KU812F Cell Activation.

Chrysanthemum zawadskii var. latilobum (CZL) has been used in Eastern medicine for the treatment of various diseases, such as pneumonia, bronchitis, cough, the common cold, pharyngitis, bladder-related disorders, gastroenteric disorders, and hypertension. In the present study, we isolated two strong antiallergic compounds from CZL, namely, eriodictyol-7-O-ß-d-glucuronide (EDG) and 5,7-dihydroxy-4-chromene (DC), and investigated their antiallergic effects in FcεRI-mediated human basophilic KU812F cells. EDG and DC downregulated the protein and messenger RNA (mRNA) expression of FcεRI on the cell surface. Moreover, Western blotting analysis showed that EDG and DC inhibited the expression of protein tyrosine kinases such as Syk and Lyn, and extracellular-regulated kinases (ERK) 1/2. These results suggested that EDG and DC, antiallergic constituents of CZL, are potential therapeutic candidates for protection against and for the treatment of allergic disorders.

Study of the pharmacokinetics of eriodictyol-6-C-ß-d-glucoside, a flavonoid of rooibos (Aspalathus linearis) extract, after its oral administration in mice.

Systemic dry syndrome affects quality of life, and various effective methods are being developed for its treatment. We recently found that rooibos (Aspalathus linearis) extract activates muscarinic M3 receptor and improves dryness in mice and humans. We identified eriodictyol-6-C-ß-D-glucoside (E6CG) as the active component affecting the secretory functions of exocrine glands; however, the pharmacokinetics and distribution of E6CG in exocrine glands have not been elucidated in mice receiving rooibos extract. We have developed a quantification method using LC-MS/MS to detect E6CG without an internal standard. Experiments on C57BL/6 mice administered rooibos extract showed that E6CG was transferred into blood plasma, with its concentration levels peaking 19.3 min after treatment. Substantial levels of E6CG were detected in the submandibular, sublingual, parotid, and lacrimal glands and in the sweat glands in palm skin. This study reports that rooibos extracts containing E6CG can be used as functional foods for improving systemic dryness.

Identification of flavonoids 3-hydroxylase from Silybum marianum (L.) Gaertn and its application in enhanced production of taxifolin / 生物工程学报

(2S)-taxifolin is an important flavonoid that has anti-inflammatory and anti-oxidation effects. It is widely used in pharmaceutical and nutraceutical industries. Flavone 3-hydroxylase (F3H) can catalyze the synthesis of (2S)-taxifolin and other 3-hydroxylated flavonoids from (2S)-eriodictyol. Due to the low catalytic efficiency of F3H, the titer of many 3-hydroxyflavones, such as taxifolin, synthesized by microbial method is relatively low. In this study, a SmF3H was identified from the transcriptome of Silybum marianum (L.) Gaertn. The results of fermentation showed that SmF3H can catalyze the flavone 3-hydroxylation reaction, and its catalytic efficiency was significantly higher than that of commonly used SlF3H from Solanum lycopersicum. Six promoters with different transcription strength were selected to optimize the synthesis pathway from the flavonoid precursor (2S)-naringenin to (2S)-taxifolin. The results showed that the highest titer of (2S)-taxifolin (695.90 mg/L in shake flask) could be obtained when the P(GAL7) promoter was used to control the expression of SmF3H. The titer of (2S)-taxifolin was further improved to 3.54 g/L in a 5-L fermenter, which is the highest titer according to current available literatures.

Eriodictyol inhibits high glucose-induced extracellular matrix accumulation, oxidative stress, and inflammation in human glomerular mesangial cells.

Diabetic nephropathy (DN) is one of the major complications of diabetes mellitus. The progression of DN has been found to be associated with high glucose (HG)-induced oxidative stress and inflammation in diabetes mellitus. Eriodictyol is a flavonoid that possesses antioxidant and anti-inflammatory effects. However, the effect of eriodictyol on DN remains unknown. In the present study, we evaluated the role of eriodictyol in mesangial cells (MCs) in response to HG condition. The results showed that eriodictyol repressed cell proliferation of HG-stimulated MCs. Treatment with eriodictyol attenuated oxidative stress, which was evidenced by increased superoxide dismutase activity as well as decreased production of reactive oxygen species (ROS) and malondialdehyde. Besides, eriodictyol suppressed the expressions of two NADPH oxidase (NOX) isoforms, NOX2 and NOX4, which are responsible for the generation of ROS. Eriodictyol suppressed the production of extracellular matrix proteins including fibronectin and Collagen IV, as well as the secretion of inflammatory cytokines including TNF-α, IL-1ß, and IL-6 in HG-induced MCs. Moreover, the HG-induced activation of Akt/NF-κB pathway was mitigated by eriodictyol. In conclusion, eriodictyol protected MCs from HG stimulation though inhibition of Akt/NF-κB pathway.

Dietary Eriodictyol Alleviates Adiposity, Hepatic Steatosis, Insulin Resistance, and Inflammation in Diet-Induced Obese Mice.

The present study aimed to investigate the molecular mechanisms underlying the anti-obesity effect of flavonoid eriodictyol (ED) supplementation in mice fed with a high-fat diet (HFD). C57BL/6N mice were fed with normal diet (ND), HFD (40 kcal% fat), or HFD + 0.005% (w/w) ED for 16 weeks. In HFD-induced obese mice, dietary ED supplementation significantly alleviated dyslipidemia and adiposity by downregulating the expression of lipogenesis-related genes in white adipose tissue (WAT), while enhancing fecal lipid excretion. ED additionally improved hepatic steatosis and decreased the production of pro-inflammatory cytokines by downregulating the expression of hepatic enzymes and the genes involved in lipogenesis and upregulating the expression of hepatic fatty acid oxidation-related enzymes and genes. In addition, ED improved insulin resistance (IR) by suppressing hepatic gluconeogenesis, enhancing glucose utilization, and modulating the production and release of two incretin hormones, namely gastric inhibitory polypeptide (GIP) and glucagon-like peptide-1 (GLP-1). Taken together, the current findings indicated that ED can protect against diet-induced obesity and related metabolic disturbances, including dyslipidemia, inflammation, fatty liver disease, and IR in diet-induced obese mice.

Protective effects of flavonoids from Coreopsis tinctoria Nutt. on experimental acute pancreatitis via Nrf-2/ARE-mediated antioxidant pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: Oxidative stress is a prominent feature of clinical acute pancreatitis (AP). Coreopsis tinctoria has been used traditionally to treat pancreas disorders like diabetes mellitus in China and Portugal and its flavonoid-rich fraction contain the main phytochemicals that have antioxidant and anti-inflammatory activities. AIM OF THE STUDY: To investigate the effects of flavonoids isolated from C. tinctoria on experimental AP and explore the potential mechanism. MATERIALS AND METHODS: LC-MS based online technique was used to analyse and isolate targeted flavonoids from C. tinctoria. Freshly isolated mouse pancreatic acinar cells were treated with taurocholic acid sodium salt hydrate (NaT, 5 mM) with or without flavonoids. Fluorescence microscopy and a plate reader were used to determine necrotic cell death pathway activation (propidium iodide), reactive oxygen species (ROS) production (H2-DCFDA) and ATP depletion (luminescence) where appropriate. AP was induced by 7 repeated intraperitoneal caerulein injections (50 µg/kg) at hourly interval in mice or retrograde infusion of taurolithocholic acid 3-sulfate disodium salt (TLCS; 5 mM, 50 µL) into the pancreatic duct in mice or infusion of NaT (3.5%, 1 mL/kg) in rats. A flavonoid was intraperitoneally administered at 0, 4, and 8 h after the first caerulein injection or post-operation. Disease severity, oxidative stress and antioxidant markers were determined. RESULTS: Total flavonoids extract and flavonoids 1-6 (C1-C6) exhibited different capacities in reducing necrotic cell death pathway activation with 0.5 mM C1, (2 R,3 R)-taxifolin 7-O-ß-D-glucopyranoside, having the best effect. C1 also significantly reduced NaT-induced ROS production and ATP depletion. C1 at 12.5 mg/kg and 8.7 mg/kg (equivalent to 12.5 mg/kg for mice) significantly reduced histopathological, biochemical and immunological parameters in the caerulein-, TLCS- and NaT-induced AP models, respectively. C1 administration increased pancreatic nuclear factor erythroid 2-related factor 2 (Nrf2) and Nrf2-medicated haeme oxygenase-1 expression and elevated pancreatic antioxidant enzymes superoxide dismutase and glutathione peroxidase levels. CONCLUSIONS: Flavonoid C1 from C. tinctoria was protective in experimental AP and this effect may at least in part be attributed to its antioxidant effects by activation of Nrf2-mediated pathways. These results suggest the potential utilisation of C. tinctoria to treat AP.

Bioactive fraction of Rhodiola algida against chronic hypoxia-induced pulmonary arterial hypertension and its anti-proliferation mechanism in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Rhodiola algida var. tangutica (Maxim.) S.H. Fu is a perennial plant of the Crassulaceae family that grows in the mountainous regions of Asia. The rhizome and roots of this plant have been long used as Tibetan folk medicine for preventing high latitude sickness. AIM OF THE STUDY: The aim of this study was to determine the effect of bioactive fraction from R. algida (ACRT) on chronic hypoxia-induced pulmonary arterial hypertension (HPAH) and to understand the possible mechanism of its pharmacodynamic actions. MATERIALS AND METHODS: Male Sprague-Dawley rats were separated into five groups: control group, hypoxia group, and hypoxia+ACRT groups (62.5, 125, and 250mg/kg/day of ACRT). The chronic hypoxic environment was created in a hypobaric chamber by adjusting the inner pressure and oxygen content for 4 weeks. After 4 weeks, major physiological parameters of pulmonary arterial hypertension such as mPAP, right ventricle index (RV/LV+S, RVHI), hematocrit (Hct) levels and the medial vessel thickness (wt%) were measured. Protein and mRNA expression levels of proliferating cell nuclear antigen (PCNA), cyclin D1, p27Kip1 and cyclin-dependent kinase 4 (CDK4)) were detected by western blotting and real time PCR respectively. Chemical profile of ACRT was revealed by ultra performance liquid chromatography coupled with quadrupole time of flight mass spectrometry (UHPLC-Q-TOF-MS/MS). RESULTS: The results showed that a successful HPAH rat model was established in a hypobaric chamber for 4 weeks, as indicated by the significant increase in mPAP, RV/LV+S, RV/BW and wt%. Compared with the normal group, administration of ACRT reduced mPAP, right ventricular hypertrophy, pulmonary small artery wall thickness, and damage in ultrastructure induced by hypoxia in rats. PCNA, cyclin D1, and CDK4 expression was reduced (p<0.05), and p27Kip1 expression increased (p<0.05) in hypoxia+ACRT groups compared to hypoxia. 38 constituents in bioactive fraction were identified by UHPLC-Q-TOF-MS/MS. CONCLUSION: Our results suggest that ACRT could alleviate chronic hypoxia-induced pulmonary arterial hypertension. And its anti-proliferation mechanism in rats based on decreasing PCNA, cyclin D1, CDK4 expression level and inhibiting p27Kip1 degradation.

Investigation of immunomodulatory and anti-inflammatory effects of eriodictyol through its cellular anti-oxidant activity.

Many studies have been performed to assess the potential utility of natural products as immunomodulatory agents to enhance host responses against infection or to ameliorate immune-based pathologies. To determine whether eriodictyol has immunomodulatory effects and clarify which types of immune effector cells are stimulated in vitro, we investigated the stimulatory effect of eriodictyol on spleen cells isolated from BALB/c mice. Eriodictyol significantly stimulated splenocyte proliferation. However, only B lymphocytes (not T lymphocytes) could be stimulated by eriodictyol in a dose-related manner. Studies assessing potential effect of eriodictyol on innate immunity reported that eriodictyol enhanced significantly the killing activity of natural killer (NK) cells, T lymphocytes, and macrophages. We also demonstrated that eriodictyol inhibited nitric oxide (NO) production and lysosomal enzyme activity in murine peritoneal macrophages cultured ex-vivo, suggesting a potential anti-inflammatory effect in situ. Eriodictyol revealed also a cellular anti-oxidant activity in splenocytes and macrophages. Furthermore, eriodictyol increased catalase activity in spleen cells. From this data, it can be concluded that eriodictyol exhibited an immunomodulatory effect that could be ascribed in part to a cytoprotective effect related to its anti-oxidant activity.