Inhibition of cytokine-induced IkappaB kinase activation as a mechanism contributing to the anti-atherogenic activity of tilianin in hyperlipidemic mice

Enhanced Anti-Inflammatory Activity of Tilianin Based on the Novel Amorphous Nanocrystals

Tilianin (Til), a flavonoid glycoside, is well-known for its therapeutic promise in treating inflammatory disorders. Its poor water solubility and permeability limit its clinical applicability. In order to overcome these restrictions, an antisolvent precipitation and ultrasonication technique was used to prepare amorphous tilianin nanocrystals (Til NCs). We have adjusted the organic solvents, oil-to-water ratio, stabilizer composition, and ultrasonic power and time by combining single-factor and central composite design (CCD) methodologies. The features of Til NCs were characterized using powder X-ray diffraction (PXRD), scanning calorimetry (DSC), and transmission electron microscopy (TEM). Specifically, the optimized Til NCs were needle-like with a particle size ranging from 90 to 130 nm. PVA (0.3%, w/v) and TPGS (0.08%, w/v) stabilized them well. For at least two months, these Til NCs stayed amorphous and showed an impressive stability at 4 °C and 25 °C. Remarkably, Til NCs dissolved almost 20 times faster in simulated intestinal fluid (SIF) than they did in crude Til. In RAW264.7 cells, Til NCs also showed a better cellular absorption as well as safety and protective qualities. Til NCs were shown to drastically lower reactive oxygen species (ROS), TNF-α, IL-1β, and IL-6 in anti-inflammatory experiments, while increasing IL-10 levels and encouraging M1 macrophages to adopt the anti-inflammatory M2 phenotype. Our results highlight the potential of amorphous Til NCs as a viable approach to improve Til's anti-inflammatory effectiveness, solubility, and dissolving rate.

Beneficial effects of flavonoids on animal models of atherosclerosis: A systematic review and meta-analysis

Atherosclerosis is the main cause of cardiovascular diseases that seriously endanger human health. The existing treatment drugs are effective, but they have some side effects. Accumulating evidence suggests that flavonoids have attracted wide attention due to their multiple cardioprotective effects and fewer side effects. PubMed, Web of Science database, Embase, and Cochrane Library were searched for studies evaluating the effects of flavonoids against atherosclerosis. 119 studies published from August 1954 to April 2023 were included. Random-effects models were performed for synthesis. Compared with the control group, flavonoids significantly reduced longitudinal and cross-sectional plaque area. The findings indicated that flavonoids significantly reduced the concentrations of serum TC, TG, and LDL-C and increased serum HDL-C concentrations. Besides, flavonoids reduced the levels of circulating pro-inflammatory factors, including TNF-α, IL-1β, and IL-6, and increased the serum IL-10 level. This study provides evidence for the potential cardiovascular benefits of flavonoids.

Tilianin alleviates lipid deposition and fibrosis in mice with nonalcoholic steatohepatitis by activating the PPARα/Nnat axis

The understanding and treatment of nonalcoholic steatohepatitis (NASH) are still very limited. This study reports the therapeutic effect of tilianin on mice with NASH and further explores its possible molecular mechanisms. A mice model of NASH was established using low-dose streptozotocin combined with a high-fat diet and tilianin treatment. Liver function was assessed by determining serum aspartate aminotransferase and alanine aminotransferase in serum. Interleukin (IL)-1β, IL-6, transforming growth factor β1 (TGF-β1), and tumor necrosis factor α (TNF-α) levels in serum were determined. Hepatocyte apoptosis was assessed using terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling staining. Oil Red O staining and boron dipyrrin staining were used to determine lipid deposition in liver tissues. Masson staining was used to evaluate liver fibrosis, and immunohistochemistry and western blot analysis were used to determine the expression of target proteins. Tilianin treatment significantly ameliorated liver function, inhibited hepatocyte apoptosis, and reduced lipid deposition and liver fibrosis in mice with NASH. The expression of neuronatin (Nnat) and peroxisome proliferator-activated receptor (PPAR) α was upregulated, whereas that of sterol regulatory element-binding protein 1 (SREBP-1), TGF-β1, nuclear factor (NF)-κB p65, and phosphorylated p65 was downregulated in the liver tissues of mice with NASH after tilianin treatment. The above effects of tilianin were significantly reversed after Nnat knock-down, but its effect on PPARα expression was unaffected. Thus, the natural drug tilianin shows potential in treatig NASH. Its mechanism of action may be related to the targeted activation of PPARα/Nnat, thereby inhibiting the activation of the NF-κB signaling pathway.

Tilianin improves lipid profile and alleviates atherosclerosis in ApoE-/- mice through up-regulation of SREBP2-mediated LDLR expression

BACKGROUND

The huge global burden of atherosclerotic cardiovascular diseases (CVDs) represents an urgent unmet need for the development of novel therapeutics. Dracocephalum moldavica L. has been used as a traditional Uygur medicine to treat various CVDs for centuries. Tilianin is a major flavonoid component of D. moldavica L. and has potential for preventing atherosclerosis. However, the molecular mechanisms that tilianin attenuate atherosclerosis are far from fully understood.

PURPOSES

The purpose of this study is to investigate the efficiency and underlying mechanisms of tilianin in controlling lipid profile and preventing atherogenesis.

METHODS

The lipid-lowering effect of tilianin was evaluated in C57BL/6 and ApoE^-/- mice by systematically determining serum biochemical parameters. The effects of tilianin on the atherosclerotic lesion were observed in aortic roots and whole aortas of ApoE^-/- mice with oil red O staining. Caecal content from ApoE^-/- mice were collected for 16S rRNA gene sequence analysis to assess the structure of the gut microbiota. The inhibition of hepatosteatosis was verified by histological examination, and a liver transcriptome analysis was performed to elucidate the tilianin-induced hepatic transcriptional alterations. Effects of tilianin on the expression and function of LDLR were examined in HepG2 cells and ApoE^-/- mice. Further mechanisms underlying the efficacy of tilianin were investigated in HepG2 cells.

RESULTS

Tilianin treatment improved lipid profiles in C57BL/6 and dyslipidemic ApoE^-/- mice, especially reducing the serum LDL-cholesterol (LDL-C) level. Significant reductions of atherosclerotic lesion area and hepatosteatosis were observed in tilianin-treated ApoE^-/- mice. The altered gut microbial composition in tilianin groups was associated with lipid metabolism and atherosclerosis. The liver transcriptome revealed that tilianin regulated the transcription of lipid metabolism-related genes. Then both in vitro and in vivo analyses revealed the potent effect of tilianin to enhance hepatic LDLR expression and its mediated LDL-C uptake. Further studies confirmed a critical role of SREBP2 in hepatic LDLR up-regulation by tilianin via increasing precursor and thus mature nuclear SREBP2 level.

CONCLUSION

This study demonstrated the lipid-lowering effect of tilianin through SREBP2-mediated transcriptional activation of LDLR. Our findings reveal a novel anti-atherosclerotic mechanism of tilianin and underlie its potential clinical use in modulating CVDs with good availability and affordability.

Tilianin improves cognition in a vascular dementia rodent model by targeting miR-193b-3p/CaM- and miR-152-3p/CaMKIIα-mediated inflammatory and apoptotic pathways

Introduction

Although vascular dementia (VaD) is the second most prevalent form of dementia, there is currently a lack of effective treatments. Tilianin, isolated from the traditional drug Dracocephalum moldavica L., may protect against ischemic injury by inhibiting oxidative stress and inflammation via the CaMKII-related pathways but with weak affinity with the CaMKII molecule. microRNAs (miRNAs), functioning in post-transcriptional regulation of gene expression, may play a role in the pathological process of VaD via cognitive impairment, neuroinflammatory response, and neuronal dysfunction. This study aimed to investigate the role of tilianin in VaD therapy and the underlying mechanism through which tilianin regulates CaMKII signaling pathways based on miRNA-associated transcriptional action.

Methods

Rats with 2-vessel occlusion (2VO), a standard model of VaD, were treated with tilianin, vehicle control, and target overexpression or downregulation. High-throughput sequencing, qRT-PCR, and western blot analyses were utilized to identify the downstream target genes and signaling pathways of tilianin involved in VaD.

Results

Our results showed that tilianin ameliorated cognitive deficits, neurodegeneration, and microglial and astrocytic activation in rats with 2VO. Subsequent high-throughput sequencing and qRT-PCR analyses revealed that tilianin increased the downregulated miR-193b-3p and miR-152-3p levels in the cortex and hippocampus of 2VO rats. Mechanistically, miR-193b-3p targeting CaM and miR-152-3p targeting CaMKIIα were identified to play a role in VaD-associated pathology, inhibiting the p38 MAPK/NF--κB p65 pathway and decreasing TNF-α and IL-6 levels. Further gain- and loss-of-function experiments for these key genes showed that tilianin-exerted cognitive improvement by activating the p38 MAPK/NF--κB p65 and Bcl-2/Bax/caspase-3/PARP pathways in the brain of 2VO rats was abolished by miR-193b-3p and miR-152-3p inhibition. Moreover, CaM and CaMKIIα overexpression eliminated the elevated effects of miR-193b-3p and miR-152-3p on tilianin's protection against ischemic injury through increased inflammatory reactions and apoptotic signaling.

Discussion

Together, these findings indicate that tilianin improves cognition by regulating the miR-193b-3p/CaM- and miR-152-3p/CaMKIIα-mediated inflammatory and apoptotic pathways, suggesting a potential small-molecule regulator of miRNA associated with inflammatory signaling for VaD treatment.

Systems Pharmacology-Based Strategy to Investigate Pharmacological Mechanisms of Total Flavonoids in Dracocephalum moldavica on Chronic Heart Failure

Heart failure (HF) is a clinical syndrome of cardiac insufficiency caused by abnormalities in cardiac structure and function that arise for various reasons, and it is the final stage of most cardiovascular diseases’ progression. Total flavonoid extract from Dracocephalum moldavica L. (TFDM) has many pharmacological and biological roles, such as cardioprotective, neuroprotective, anti-atherogenic, antihypertensive, anti-diabetic, anti-inflammatory, antioxidant, etc. However, its effect on HF and its molecular mechanism are still unclear. In this study, we used systems pharmacology and an animal model of HF to investigate the cardioprotective effect of TFDM and its molecular mechanism. Eleven compounds in TFDM were obtained from the literature, and 114 overlapping genes related to TFDM and HF were collected from several databases. A PPI network and C-T network were established, and GO enrichment analysis and KEGG pathway analysis were performed. The top targets from the PPI network and C-T network were validated using molecular docking. The pharmacological activity was investigated in an HFpEF (heart failure with preserved ejection fraction) mouse model. This study shows that TFDM has a protective effect on HFpEF, and its protective mechanism may be related to the regulation of proinflammatory cytokines, apoptosis-related genes, fibrosis-related genes, etc. Collectively, this study offers new insights for researchers to understand the protective effect and mechanism of TFDM against HFpEF using a network pharmacology method and a murine model of HFpEF, which suggest that TFDM is a promising therapy for HFpEF in the clinic.

Tilianin: A Potential Natural Lead Molecule for New Drug Design and Development for the Treatment of Cardiovascular Disorders

Cardiovascular disorders (CVDs) are the leading risk factor for death worldwide, and research into the processes and treatment regimens has received a lot of attention. Tilianin is a flavonoid glycoside that can be found in a wide range of medicinal plants and is most commonly obtained from Dracocephalum moldavica. Due to its extensive range of biological actions, it has become a well-known molecule in recent years. In particular, numerous studies have shown that tilianin has cardioprotective properties against CVDs. Hence, this review summarises tilianin’s preclinical research in CVDs, as well as its mechanism of action and opportunities in future drug development. The physicochemical and drug-likeness properties, as well as the toxicity profile, were also highlighted. Tilianin can be a natural lead molecule in the therapy of CVDs such as coronary heart disease, angina pectoris, hypertension, and myocardial ischemia, according to scientific evidence. Free radical scavenging, inflammation control, mitochondrial function regulation, and related signalling pathways are all thought to play a role in tilianin’s cardioprotective actions. Finally, we discuss tilianin-derived compounds, as well as the limitations and opportunities of using tilianin as a lead molecule in drug development for CVDs. Overall, the scientific evidence presented in this review supports that tilianin and its derivatives could be used as a lead molecule in CVD drug development initiatives.

In Vitro and In Vivo Antimalarial Activities and Toxicological Assessment of Pogostemon Cablin (Blanco) Benth

The aim of this study was to investigate the antimalarial activities and toxicity of Pogostemon cablin extracts. In vitro activities against the chloroquine-resistant Plasmodium falciparum K1 strain were assessed by using the Plasmodium lactate dehydrogenase enzyme (pLDH) assay, while in vivo activity against the Plasmodium berghei ANKA strain in mice was investigated using a 4-day suppressive test. The in vitro and in vivo toxicity were determined in Vero cells and mice, respectively. The ethanolic extract possessed antimalarial activity with an IC₅₀ of 24.49 ± 0.01 µg/ml, whereas the aqueous extract showed an IC₅₀ of 549.30 ± 0.07 µg/ml. Cytotoxic analyses of the ethanolic and aqueous extracts revealed a nontoxic effect on Vero cells at a concentration of 80 µg/ml. Based on a preliminary study of in vitro antimalarial activity, the ethanolic extract was chosen as a potential agent for further in vivo antimalarial activity analysis in mice. The ethanolic extract, which showed no toxic effect on mice at a dose of 2000 mg/kg body weight, significantly suppressed parasitemia in mice by 38.41%, 45.12% and 89.00% at doses of 200, 400 and 600 mg/kg body weight, respectively. In conclusion, this study shows that the ethanolic P. cablin extract possesses in vitro and in vivo antimalarial activity without toxic effects.

Tilianin Protects against Ischemia/Reperfusion-Induced Myocardial Injury through the Inhibition of the Ca2+/Calmodulin-Dependent Protein Kinase II-Dependent Apoptotic and Inflammatory Signaling Pathways

Tilianin is a naturally occurring phenolic compound with a cardioprotective effect against myocardial ischemia/reperfusion injury (MIRI). The aim of our study was to determine the potential targets and mechanism of action of tilianin against cardiac injury induced by MIRI. An in silico docking model was used in this study for binding mode analysis between tilianin and Ca²⁺/calmodulin-dependent protein kinase II (CaMKII). Oxygen-glucose deprivation/reperfusion- (OGD/R-) injured H9c2 cardiomyocytes and ischemia/reperfusion- (I/R-) injured isolated rat hearts were developed as in vitro and ex vivo models, respectively, which were both treated with tilianin in the absence or presence of a specific CaMKII inhibitor KN93 for target verification and mechanistic exploration. Results demonstrated the ability of tilianin to facilitater the recovery of OGD/R-induced cardiomyocyte injury and the maintenance of cardiac function in I/R-injured hearts. Tilianin interacted with CaMKIIδ with an efficient binding performance, a favorable binding score, and restraining p-CaMKII and ox-CaMKII expression in cardiomyocytes injured by MIRI. Importantly, inhibition of CaMKII abolished tilianin-mediated recovery of OGD/R-induced cardiomyocyte injury and maintenance of cardiac function in I/R-injured hearts, accompanied by the disability to protect mitochondrial function. Furthermore, the protective effects of tilianin towards mitochondrion-associated proapoptotic and antiapoptotic protein counterbalance and c-Jun N-terminal kinase (JNK)/nuclear factor- (NF-) κB-related inflammation suppression were both abolished after pharmacological inhibition of CaMKII. Our investigation indicated that the inhibition of CaMKII-mediated mitochondrial apoptosis and JNK/NF-κB inflammation might be considered as a pivotal mechanism used by tilianin to exert its protective effects on MIRI cardiac damage.

Improved oral delivery of tilianin through lipid-polymer hybrid nanoparticles to enhance bioavailability

Tilianin (TIL) may prevent and treat myocardial ischemia reperfusion injuries. However, its oral administration is hampered by its low bioavailability. The present study aimed to formulate lipid-polymer hybrid nanoparticles (LPHNs) as carriers for the sustained release and oral bioavailability enhancement of TIL in vitro and in vivo. A nanodrug delivery system of TIL-loaded LPHNs (TIL-LPHNs) was constructed. TIL-LPHNs were prepared via a self-assembly method, and their particle size, polymer dispersity index (PDI), zeta potential, encapsulation efficiency (EE) and morphology were investigated. In addition, pharmacokinetic studies were performed in vivo. The TIL-LPHN formulation produced a spherical, homogeneous, smooth surface and multi-lamellar structured nanoparticles. The particle size and distribution profile of TIL-LPHNs had a mean particle diameter of 54.6 ± 5.3 nm and PDI of 0.112 ± 0.017. The zeta potential was -33.4 ± 4.7 mV. The EE of TIL-LPHNs was 86.6 ± 3.6%, which was determined with the dialysis method. The TIL-LPHNs significantly enhanced the oral bioavailability of TIL with a 3.7-fold increase in the area under the concentration-time curve in comparison with the TIL solution. These findings support the potential use of LPHNs in improving the stability and bioavailability of TIL via oral administration.

Atheroprotective Mechanisms of Tilianin by Inhibiting Inflammation Through Down-Regulating NF-κB Pathway and Foam Cells Formation

Tilianin, a representative flavonoid ingredient of Dracocephalum moldavica L., has been used to treat several diseases for centuries, including atherosclerosis (AS). However, pharmacological mechanisms underlying its biological functions remain elusive. In the present study, we investigated the anti-AS mechanisms of tilianin through establishing in vitro models using three types of cells that contributed to AS progression, including macrophage, vascular smooth muscle cells and human umbilical vein endothelial cells, which were proved to be involve in LPS/TNF-α/oxidized low density lipoprotein (ox-LDL)-induced inflammation and ox-LDL induced foam cell formation. Our results indicate that tilianin significantly suppressed LPS induced inflammatory responses on macrophage and remarkably inhibited TNF-α induced VSMCs proliferation and migration. Furthermore, the anti-inflammatory effect of tilianin on macrophages and VSMCs was proved to be mainly by downregulating TNF-α/NF-κB pathway. Moreover, our results demonstrate that tilianin significantly ameliorated ox-LDL induced macrophages oriented foam cells formation through repressing mRNA expression of SR-A1 and inducting the expression of genes related to cholesterol efflux including SRB-1 and ABCA1. However, tilianin had no effect on ox-LDL induced HUVECs injury.

Analysis of tilianin and acacetin in Agastache rugosa by high-performance liquid chromatography with ionic liquids-ultrasound based extraction

Ionic liquid 1-butyl-3-methylimidazolium bromide-methanol-based ultrasonic-assisted extraction (ILUAE) was used to extract tilianin and acacetin from the aerial parts of Agastache rugose (A. rugose), and simultaneously determined by reversed phase high performance liquid chromatographic (RP-HPLC) method with ultraviolet detection (RP-HPLC-UV). An InertSustain RP-C₁₈ column was used with the mobile phase consisting of methanol and 0.2% acetic acid as gradient elution at the detection wavelength of 332 nm. The flow rate was 0.8 mL/min, and the column temperature was 30 °C. Under the optimized conditions, tilianin and acacetin displayed good linearity in the ranges of 0.0595–4.76 and 0.0585–4.68 μg/mL, respectively, with the average recoveries being 96.93 and 97.88%, respectively. The method of ILUAE was compared with the traditional methods, it exhibited higher efficiency, higher reproducibility and environmental friendly in analyzing the active compounds in traditional Chinese medicines (TCMs).

Involvement of the GABAergic system in the neuroprotective and sedative effects of acacetin 7-O-glucoside in rodents

Purpose: Characterization of sedative, possible anticonvulsant, and protective effects of Acacetin-7-O-glucoside (7-ACAG).

Methods: 7-ACAG was separated and its purity was analyzed. Its sedative and anti-seizure effects (1, 10, 20, and 40 mg/kg) were evaluated in male mice. Synaptic responses were acquired from area CA1 of hippocampal slices obtained from male Wistar rats. Rats were subjected to stereotaxic surgeries to allow Electroencephalographic (EEG) recordings. Functional recovery was evaluated by measuring the time rats spent in completing the motor task. Then the rats were subjected to right hemiplegia and administered 7-ACAG (40 mg/kg) 1 h or 24 h after surgery. Brains of each group of rats were prepared for histological analysis.

Results: Effective sedative doses of 7-ACAG comprised those between 20 and 40 mg/kg. Latency and duration of the epileptiform crisis were delayed by this flavonoid. 7-ACAG decreased the synaptic response in vitro, similar to Gamma-aminobutyric acid (GABA) effects. The flavonoid facilitated functional recovery. This data was associated with preserved cytoarchitecture in brain cortex and hippocampus.

Conclusions: 7-ACAG possesses anticonvulsive and sedative effects. Results suggest that GABAergic activity and neuroprotection are involved in the mechanism of action of 7-ACAG and support this compound’s being a potential drug for treatment of anxiety or post-operative conditions caused by neurosurgeries.

Protective activity ethanol extract of the fruits of Illicium verum against atherogenesis in apolipoprotein E knockout mice

BACKGROUND

Illicium verum Hook. fil. Illiciaceae (Illicium v.) has been traditionally used in herbal medicine for treating many inflammatory diseases, including skin inflammation and rheumatism. We investigated its use as a preventive agent against inflammatory and vascular diseases in a murine model of atherosclerosis using apolipoprotein E-knockout (ApoE(-/-)) mice fed on a high-fat diet (HFD).

METHODS

We investigated the effect of Illicium v. on cytotoxicity, NF-κB activity, and adhesion molecule expression in TNF-α--stimulated HASMCs (Human Aortic smooth muscle cells). ApoE(-/-)mice, fed a HFD and treated daily for 12 weeks by oral administration of either Illicium v. (100 or 200 mg/kg) or atorvastatin (10 mg/kg), were evaluated for atherosclerotic lesions and inflammatory responses by performing Oil red O and iNOS staining, respectively. Expression of inflammatory cytokines (i.e., NF-κB, TNF-α, IL-1β, COX, IκB-α, Iκκ-α/β) and adhesion molecules in the aorta were measured by western blot analysis.

RESULTS

In TNF-α-stimulated HASMCs, Illicium v. treatment decreased NF-κB transcriptional activity, and NF-κB protein levels were reduced in a dose-dependent manner over a range of 10-100 μg/mL Illicium v. Also, Illicium v. attenuated the expression of adhesion molecules that are responsible for inflammation in these cells. In animal experiments, treatment with Illicium v. or atorvastatin counteracted the characteristic changes in body weight, blood pressure, and lipid levels seen in HFD-fed ApoE(-/-) mice. In addition, Illicium v. treatment reduced aortic atherosclerotic plaque lesions and the immunoreactivity of iNOS activation. The aortic expression of inflammatory adhesion molecules and cytokines (TNF-α, IL-1β, NF-κB, COX, IκB-α, Iκκ-α/β), which is characteristic of HFD-fed ApoE(-/-) mice, was attenuated by 12-week treatment with daily oral administration of Illicium v. or atorvastatin, and the most potent effect was seen with the herbal tincture.

CONCLUSIONS

The beneficial effects of Illicium v. are consistent with a significant decrease in the iNOS-mediated inflammatory response, resulting in reduction of inflammation-associated gene expression. Treatment with Illicium v. may be the basis of a novel therapeutic strategy for hyperlipidemia-atherosclerosis.

A combined strategy of mass fragmentation, post-column cobalt complexation and shift in ultraviolet absorption spectra to determine the uridine 5'-diphospho-glucuronosyltransferase metabolism profiling of flavones after oral administration of a flavone mixture in rats

The use of dietary flavones is becoming increasingly popular for their prevention of cancers, cardiovascular diseases, and other diseases. Despite many pharmacokinetic studies on flavone mixtures, the position(s) of glucuronidation sites on the flavone skeleton in vivo remain(s) uncertain because of the lack of a convenient method to differentiate the isomers in biological samples. Accordingly, this study aimed to develop a new strategy to identify the position of the mono-O-glucuronide of flavones in vivo and to simultaneously determine the parent agent and its major metabolites responsible for complex pharmacokinetic characteristics. The novel strategy involves accurate mass measurements of flavone glucuronides, their [Co(II) (flavone glucuronide-H) (4,7-diphenyl-1,10-phenanthroline)2](+) complexes generated via the post-column addition of CoBr2 and 4,7-diphenyl-1,10-phenanthroline, and their mass spectrometric fragmentation by UPLC-DAD-Q-TOF and the comparison of retention times with biosynthesized standards of different isomers that were identified by analyzing the shift in UV spectra compared with the spectra of their respective aglycones. We successfully generated a metabolite profiling of flavones in rat plasma after oral administration of a flavone mixture from Dracocephalum moldavica L., which was used here as the model to demonstrate the strategy. Twelve flavone glucuronides, which were glucuronidated derivatives of acacetin, apigenin, luteolin, diosmetin, chrysoeriol and cirsimaritin, were detected and identified. Glucuronidation of the flavone skeleton at the 3'-/7-position was more prevalent, however, luteolin 4'-glucuronide levels exceeded luteolin 7-glucuronide levels. Based on the UDP-glucuronosyltransferase (UGT) metabolism profiling of flavones in rat plasma, six main compounds (tilianin, acacetin 7-glucuronide, apigenin 7-glucuronide, luteolin 3'-glucuronide, acacetin, and apigenin) were selected as pharmacokinetic markers. Pharmacokinetic results indicated that their maximal concentrations in blood were obtained within 0.4h, except for the concentration of luteolin 3'-glucronide (approximately 9h). Rat exposure was practically non-linear under the studied dosages (200 to 400mg/kg).

Triple Recycling Processes Impact Systemic and Local Bioavailability of Orally Administered Flavonoids

Triple recycling (i.e., enterohepatic, enteric and local recycling) plays a central role in governing the disposition of phenolics such as flavonoids, resulting in low systemic bioavailability but higher gut bioavailability and longer than expected apparent half-life. The present study aims to investigate the coexistence of these recycling schemes using model bioactive flavonoid tilianin and a four-site perfused rat intestinal model in the presence or absence of a lactase phlorizin hydrolase (LPH) inhibitor gluconolactone and/or a glucuronidase inhibitor saccharolactone. The result showed that tilianin could be metabolized into tilianin glucuronide, acacetin, and acacetin glucuronide, which are excreted into the bile and luminal perfusate (highest in the duodenum and lowest in the colon). Gluconolactone (20 mM) significantly reduced the absorption of tilianin and the enteric and biliary excretion of acacetin glucuronide. Saccharolactone (0.1 mM) alone or in combination of gluconolactone also remarkably reduced the biliary and intestinal excretion of acacetin glucuronide. Acacetin glucuronides from bile or perfusate were rapidly hydrolyzed by bacterial β-glucuronidases to acacetin, enabling enterohepatic and enteric recycling. Moreover, saccharolactone-sensitive tilianin disposition and glucuronide deconjugation, which was more active in the small intestine than the colon, points to the small intestinal origin of the deconjugation enzyme and supports the presence of local recycling scheme. In conclusion, our studies have demonstrated triple recycling of a bioactive phenolic (i.e., a model flavonoid), and this recycling may have an impact on the site and duration of polyphenols pharmacokinetics in vivo.

Phytochemistry and bioactivity of aromatic and medicinal plants from the genus Agastache (Lamiaceae)

Agastache is a small genus of Lamiaceae, comprising 22 species of perennial aromatic medicinal herbs. In this article, we review recent advances in phytochemical, pharmacological, biotechnological and molecular research on Agastache. The phytochemical profile of all Agastache species studied to date is generally similar, consisted of two main metabolic classes-phenylpropanoids and terpenoids. In the relatively variable essential oils, most populations of different Agastache species contain over 50 % of a phenylallyl compound-estragole. Also, other volatile compounds (methyleugenol, pulegone, menthone, isomenthone and spathulenol) were reported in various proportions. Major non-volatile metabolites belong to phenolic compounds, such as caffeic acid derivatives, especially rosmarinic acid as well as several flavones and flavone glycosides like acacetin, tilianin, agastachoside, and a rare dimeric malonyl flavone (agastachin). Two unique lignans-agastenol and agastinol-were also isolated. Terpenoids include triterpenoids of oleanane-type (maslinic acid, oleanolic acid and β-amyrin), ursane-type (ursolic acid, corosolic acid and α-amyrin), and typical plant sterols, as well as abietane-type oxidized diterpenes (e.g., agastaquinone, agastol, and others). The bioactivity of various extracts or individual compounds in vitro and in vivo include antimicrobial, antiviral and anti-mutagenic activity, cytotoxic activity to cancer cell lines, and anti-nociceptive, anti-inflammatory, anti-atherogenic, antioxidant as well as biocidal activity to several foodstuff pests. Biotechnological and molecular studies have focused on in vitro propagation and enhancing the biosynthesis of bioactive metabolites in cell or organ cultures, as well as on the expression of genes involved in phenolic biosynthesis.

Aqueous extract of unripe Rubus coreanus fruit attenuates atherosclerosis by improving blood lipid profile and inhibiting NF-κB activation via phase II gene expression

ETHNOPHARMACOLOGICAL RELEVANCE

The fruit of Rubus coreanus has been used as a traditional herbal medicine for alleviation of inflammatory and vascular diseases in Asian countries.

AIM OF THE STUDY

The anti-atherogenic effect of unripe Rubus coreanus fruit extract (URFE) and its underlying mechanism were analyzed in mice fed a high-fat diet (HFD) and in cell culture system.

MATERIALS AND METHODS

Mouse was freely given HFD alone or supplemented with URFE for 14 weeks, followed by analysis of atherosclerotic lesions and serum lipid levels. For in vitro assay, macrophages were pretreated with URFE, followed by stimulation with lipopolysaccharide (LPS). Expression levels of inflammatory genes (TNF-α, IL-1β, and iNOS) and phase II genes (heme oxygenase-1, glutamate cysteine lygase, and peroxiredoxine-1) as well as intracellular reactive oxygen species (ROS) level and NF-κB activation pathway were analyzed in cultured macrophages as well as mouse sera and aortic tissues.

RESULTS

URFE supplementation reduced HFD-induced atherosclerotic lesion formation which was correlated with decreased levels of lipids, lipid peroxides, and inflammatory mediators (TNF-α, IL-1β, and nitric oxide) in sera as well as suppression of inflammatory gene in aortic tissues. In addition, pre-treatment of macrophages with URFE also suppressed LPS-induced NF-κB activation, ROS production, and inflammatory and phase II gene expressions. Inhibition of phase II enzyme and protein activities attenuated the suppressive effects URFE on ROS production, NF-κB activation, and inflammatory gene expression.

CONCLUSION

These results suggest that URFE attenuates atherosclerosis by improving blood lipid profile and inhibiting NF-κB activation via phase II antioxidant gene expression.

Dose-dependent antihypertensive determination and toxicological studies of tilianin isolated from Agastache mexicana

ETHNOPHARMACOLOGICAL RELEVANCE

Agastache mexicana is used in Mexican traditional medicine for the treatment of hypertension, anxiety and related diseases.

AIM OF THE STUDY

Current work was developed to establish pharmacological/toxicological parameters of tilianin, a flavone extracted from Agastache mexicana in order to propose it for clinical trials.

MATERIALS AND METHODS

Acute and sub-acute toxicology studies in Imprinting Control Region (ICR) mice and median effective dose (ED50) determination in conscious spontaneously hypertensive rats (SHR) were done.

RESULTS

A median lethal dose (LD50) of 6624 mg/kg (6201, 7076) in mice and significant antihypertensive effect (ED50=53.51 mg/kg) in SHR were determined. Moreover, sub-acute oral administration of tilianin did not alter body weight, clinical chemistry parameters (alanine amino-transferase, aspartate amino-transferase, total cholesterol, high density lipoprotein, low density lipoprotein, triglycerides, glucose and insulin), and also did not induce any toxic or adverse effects on kidney, heart, liver, and lung functions.

CONCLUSIONS

We have shown that tilianin, isolated from Agastache mexicana, was not toxic for rodents. Also, its antihypertensive effect was dose-dependent and ED50 (53.51 mg/kg) calculated was lesser than LD50 determined (6624 mg/kg), which suggest a wide range of pharmacology-toxicology patterns. Results support the hypothesis that tilianin must be investigated and developed for clinical trials as antihypertensive drug.

Ginseng Berry Extract Prevents Atherogenesis via Anti-Inflammatory Action by Upregulating Phase II Gene Expression

Ginseng berry possesses higher ginsenoside content than its root, which has been traditionally used in herbal medicine for many human diseases, including atherosclerosis. We here examined the antiatherogenic effects of the Korean ginseng berry extract (KGBE) and investigated its underlying mechanism of action in vitro and in vivo. Administration of KGBE decreased atherosclerotic lesions, which was inversely correlated with the expression levels of phase II genes to include heme oxygenase-1 (HO-1) and glutamine-cysteine ligase (GCL). Furthermore, KGBE administration suppressed NF-κB-mediated expression of atherogenic inflammatory genes (TNF-α, IL-1β, iNOS, COX-2, ICAM-1, and VCAM-1), without altering serum cholesterol levels, in ApoE^−/− mice fed a high fat-diet. Treatment with KGBE increased phase II gene expression and suppressed lipopolysaccharide-induced reactive oxygen species production, NF-κB activation, and inflammatory gene expression in primary macrophages. Importantly, these cellular events were blocked by selective inhibitors of HO-1 and GCL. In addition, these inhibitors reversed the suppressive effect of KGBE on TNF-α-mediated induction of ICAM-1 and VCAM-1, resulting in decreased interaction between endothelial cells and monocytes. These results suggest that KGBE ameliorates atherosclerosis by inhibiting NF-κB-mediated expression of atherogenic genes via upregulation of phase II enzymes and thus has therapeutic or preventive potential for atherosclerosis.

Validated liquid chromatographic method and analysis of content of tilianin on several extracts obtained from Agastache mexicana and its correlation with vasorelaxant effect

ETHNOPHARMACOLOGICAL RELEVANCE

To optimize the obtention of tilianin, an antihypertensive flavonoid isolated from Agastache mexicana (Lamiaceae), a medicinal plant used in Mexico for the treatment of hypertension. Also, a validated HPLC method to quantify tilianin from different extracts, obtained by several extraction methods, was developed.

MATERIALS AND METHODS

The aerial parts of Agastache mexicana were dried at different temperatures (22, 40, 50, 90, 100 and 180°C) and the dry material was extracted with methanol by maceration to compare the content of the active constituent tilianin in the samples. Furthermore, EtOH:H(2)O (7:3), infusion and decoction extracts were prepared from air-dried samples at room temperature to compare the content and composition of the different extraction methods. Moreover, an ex vivo vasorelaxant test on endothelium-intact aortic rat rings was conducted, in order to correlate the presence of tilianin with the activity of each extract.

RESULTS

Higher concentration and amounts of tilianin were determined from chromatograms in the obtained methanolic extracts from plant material dried at 90, 50, 40 and 22°C, followed by 100°C; however, lower concentrations were observed in dried at 180°C and EtOH:H(2)O (7:3). It is worth to notice that methanolic extracts with higher amount of tilianin were the most potent vasorelaxant extracts, even though these extracts were less potent than carbachol, a positive control used. Finally, decoction, infusion and EtOH:H(2)O (7:3) extracts did not show any vasorelaxant effect.

CONCLUSION

Results suggest that extracts with higher concentration of tilianin possess the best vasorelaxant activity, which allowed us to have a HPLC method for future quality control for this medicinal plant.

Active principle of kimchi, 3-(4'-hydroxyl-3',5'-dimethoxyphenyl)propionic acid, retards fatty streak formation at aortic sinus of apolipoprotein E knockout mice

We examined the beneficial effects of an active principle in kimchi, 3-(4'-hydroxyl-3',5'-dimethoxyphenyl)propionic acid (HDMPPA), on atherogenesis in apolipoprotein E knockout (apoE KO) mice. ApoE KO mice were fed an atherogenic diet containing 1% cholesterol (control group) with an intraperitoneal injection of chemically synthesized HDMPPA (10 mg/kg/day) (HDMPPA group) for 8 weeks. The aortic sinus atherosclerotic lesion size in the HDMPPA group (n = 10) was significantly smaller (control vs. HDMPPA, 280,790 vs. 165,409 microm(2), P < .001). The level of reactive oxygen species (ROS) in the HDMPPA group was lower by 14%, compared with the control group (P < .05). Aortic NADPH oxidase activity was significantly lower in the HDMPPA group than in the control group. HDMPPA suppressed the mRNA expression of p47phox and rac-1 of NADPH oxidase by 27.2% and 46.0%, respectively, compared with values of the control group. In conclusion, HDMPPA in kimchi may attenuate atherosclerosis in apoE KO mice through retardation of ROS generation via down-regulating the mRNA expression of p47phox and rac-1, which are the components of NADPH oxidase.