Perilla seed oil in combination with nobiletin-rich ponkan powder enhances cognitive function in healthy elderly Japanese individuals: a possible supplement for brain health in the elderly.

Perilla (Perilla frutescens) seed oil (PO), rich in α-linolenic acid (ALA), can improve cognitive function in healthy elderly Japanese people. Here, supplements containing either PO alone or PO with nobiletin-rich air-dried immature ponkan powder were examined for their effects on cognitive function in 49 healthy elderly Japanese individuals. Patients were enrolled in a 12-month randomized, double-blind, parallel-armed study. Randomized participants in the PO group received soft gelatin capsules containing 1.47 mL (0.88 g of ALA) of PO daily, and those in the PO + ponkan powder (POPP) group received soft gelatin capsules containing both 1.47 mL of PO and 1.12 g ponkan powder (2.91 mg of nobiletin) daily. At the end of intervention, the POPP group showed significantly higher cognitive index scores than the PO group. The pro-cognitive effects of POPP treatment were accompanied by increases in ALA and docosahexaenoic acid levels in red blood cell plasma membranes, serum brain-derived neurotropic factor (BDNF) levels, and biological antioxidant potential. We demonstrate that 12-month intervention with POPP enhances serum BDNF and antioxidant potential, and may improve age-related cognitive impairment in healthy elderly people by increasing red blood cell ω-3 fatty acid levels. Clinical Trial Registry, UMIN000040863.

Tangeretin prevents obesity by modulating systemic inflammation, fat browning, and gut microbiota in high-fat diet-induced obese C57BL/6 mice.

Obesity and associated comorbidities are closely linked to gut microbiota dysbiosis, energy balance, and chronic inflammation. Tangeretin, a key citrus polymethoxylated flavone (PMF), is abundant in citrus fruits and has preventative and therapeutic effects for numerous diseases. The current study investigated the effects and possible mechanisms of tangeretin supplementation in preventing obesity in high-fat diet (HFD)-fed mice. Treatment of HFD-fed mice with tangeretin potently ameliorated HFD-induced body weight, liver steatosis, glucose intolerance, and insulin resistance. Tangeretin mitigated systemic chronic inflammation by reducing metabolic endotoxemia and inflammation-related gene expression in HFD-fed mice. An increased number of small brown adipocytes possessing multilocular and cytoplasmic lipid droplets and upregulation of thermogenic gene expression were observed after tangeretin treatment. 16S rRNA amplicon sequencing indicated that tangeretin markedly altered the gut microbiota composition (richness and diversity) and reversed 16 operational taxonomic units (OTUs) back to levels seen in mice consuming a normal chow diet (NCD). Notably, tangeretin decreased the ratio of Firmicutes-to-Bacteroidetes and greatly enriched Bacteroides and Lactobacillus. Overall, our results suggest that long-term supplementation with citrus tangeretin ameliorates the phenotype of obesity by improving adipose thermogenesis and reducing systemic inflammation and gut microbiota dysbiosis, which provides a good basis for studying the mechanism of tangeretin's beneficial effects.

Development of a novel anti-liver fibrosis formula with luteolin, licochalcone A, aloe-emodin and acacetin by network pharmacology and transcriptomics analysis.

CONTEXT: Xiaoyaosan decoction (XYS), a classical Traditional Chinese Medicine (TCM) formula is used to treat liver fibrosis in clinics. OBJECTIVE: This study explores defined compound combinations from XYS decoction to treat liver fibrosis. MATERIALS AND METHODS: Network pharmacology combined with transcriptomics analysis was used to analyze the XYS decoction and liver depression and spleen deficiency syndrome liver fibrosis. From the constructed XYS-Syndrome-liver fibrosis network, the top 10 active formulas were developed by topological analysis according to network stability. The most active formula was determined by in vitro study. The anti-fibrosis effect was evaluated by in vitro and in vivo studies. RESULTS: According to the network XYS-Syndrome-liver fibrosis network, 8 key compounds and 255 combinations were predicted from in XYS. Luteolin, licochalcone A, aloe-emodin and acacetin formula (LLAAF) had a synergistic effect on the proliferation inhibition of hepatic stellate cells compared to individual compounds alone. The treatment of XYS and LLAAF showed a similar anti-liver fibrotic effect that reduced histopathological changes of liver fibrosis, Hyp content and levels of α-SMA and collagen I in CCl4-induced liver fibrosis in rats. Transcriptomics analysis revealed LLAAF regulated PI3K-Akt, AMPK, FoxO, Jak-STAT3, P53, cell cycle, focal adhesion, and PPAR signalling. Furthermore, LLAAF was confirmed to regulate Jak-STAT and PI3K-Akt-FoxO signalling in vitro and in vivo. CONCLUSIONS: This study developed a novel anti-liver formula LLAAF from XYS, and demonstrated its anti-liver fibrotic activity which may be involved in the regulation of Jak-STAT and PI3K-Akt-FoxO signalling.

The pharmacokinetic study on the interaction between nobiletin and anemarsaponin BII in vivo and in vitro.

CONTEXT: The interaction between nobiletin and anemarsaponin BII could affect the pharmacological activity of these two drugs during their combination. OBJECTIVE: The co-administration of nobiletin and anemarsaponin BII was investigated to explore the interaction and the potential mechanism. MATERIALS AND METHODS: Male Sprague-Dawley rats were only orally administrated with 50 mg/kg nobiletin as the control and another six rats were pre-treated with 100 mg/kg anemarsaponin BII for 7 d followed by the administration of nobiletin. The transport and metabolic stability of nobiletin were evaluated in vitro, and the effect of anemarsaponin BII on the activity of CYP3A4 was also assessed to explore the potential mechanism underlying the interaction. RESULTS: The increasing Cmax (2309.67 ± 68.06 µg/L vs. 1767.67 ± 68.86 µg/L), AUC (28.84 ± 1.34 mg/L × h vs. 19.57 ± 2.76 mg/L × h), prolonged t1/2 (9.80 ± 2.33 h vs. 6.24 ± 1.53 h), and decreased clearance rate (1.46 ± 0.26 vs. 2.42 ± 0.40) of nobilein was observed in rats. Anemarsaponin BII significantly enhanced the metabolic stability of nobiletin in rat liver microsomes (half-life increased from 31.56 min to 39.44 min) and suppressed the transport of nobiletin in Caco-2 cells (efflux rate decreased from 1.57 ± 0.04 to 1.30 ± 0.03). The inhibitory effect of anemarsaponin BII on CYP3A4 was also found with an IC50 value of 10.23 µM. DISCUSSION AND CONCLUSIONS: The interaction between anemarsaponin BII and nobiletin was induced by the inhibition of CYP3A4, which should draw special attention in their clinical co-administration.

Tangeretin boosts the anticancer activity of metformin in breast cancer cells via curbing the energy production.

BACKGROUND: Breast cancer is the first leading cause of women cancer-related deaths worldwide. While there are many proposed treatments for breast cancer, low efficacy, toxicity, and resistance are still major therapeutic obstacles. Thus, there is a need for safer and more effective therapeutic approaches. Because of the direct link between obesity and carcinogenesis, energy restriction mimetic agents (ERMAs) such as the antidiabetic agent, metformin was proposed as a novel antiproliferative agent. However, the anticancer dose of metformin alone is relatively high and impractical to be implemented safely in patients. The current work aimed to sensitize resistant breast cancer cells to metformin's antiproliferative effect using the natural potential anticancer agent, tangeretin. METHODS: The possible synergistic combination between metformin and tangeretin was initially evaluated using MTT cell viability assay in different breast cancer cell lines (MCF-7, MDA-MB-231, and their resistant phenotype). The possible mechanisms of synergy were investigated via Western blotting analysis, reactive oxygen species (ROS) measurement, annexin/PI assay, cell cycle analysis, and wound healing assay. RESULTS: The results indicated the ability of tangeretin to improve the anticancer activity of metformin. Interestingly, the improved activity was almost equally observed in both parental and resistant cancer cells, which underlines the importance of this combination in cases of the emergence of resistance. The synergy was mediated through the enhanced activation of AMPK and ROS generation in addition to the improved inhibition of cell migration, induction of cell cycle arrest, and apoptosis in cancer cells. CONCLUSION: The current work underscores the importance of metformin as an ERMA in tackling breast cancer and as a novel approach to boost its anticancer activity via a synergistic combination with tangeretin.

Comparative Analyses of Bioavailability, Biotransformation, and Excretion of Nobiletin in Lean and Obese Rats.

Nobiletin, one of the prevalent polymethoxyflavones in citrus peels, was reported to possess various health benefits. We conducted the excretion study and pharmacokinetics study of nobiletin via oral administration and intravenous injection and 15 day consecutive dosing study using the high fat diet-induced obese rats and their lean counterparts. By comparing the demethylated metabolite profiles in the urine and feces, gut microbiota demonstrated greater biotransformation activity on nobiletin than the host. The absolute oral bioavailability of nobiletin in lean (22.37% ± 4.52%) and obese (18.67% ± 4.80%) rats has a negligible statistically significant difference (P > 0.05). However, a higher extent of demethylated metabolites was found in the feces and plasma of obese rats than lean rats (P < 0.05). Moreover, the consecutive dosing of nobiletin might lead to a higher extent of demethylated metabolites in the plasma and in feces. These results suggested that gut microbiota played important roles in nobiletin metabolism.

Effect of a Combination of Citrus Flavones and Flavanones and Olive Polyphenols for the Reduction of Cardiovascular Disease Risk: An Exploratory Randomized, Double-Blind, Placebo-Controlled Study in Healthy Subjects.

A single-center, randomized, double-blind controlled trial was conducted to assess the efficacy of a food supplement based on a combination of grapefruit, bitter orange, and olive extracts administered for eight weeks (n = 51) versus placebo (n = 45) on reduction of cardiovascular risk in healthy volunteers. Study variables included flow-mediated vasodilation (FMD), blood pressure (BP), lipid profile, thrombotic status, oxidative stress biomarkers, inflammation-related biomarkers, anthropometric variables, quality of life, and physical activity. The per-protocol data set was analyzed. In the active product group, there were statistically significant within-group differences at eight weeks as compared with baseline in FMD, systolic and diastolic BP, total cholesterol, LDL-C, LDL-oxidase, oxidized/reduced glutathione ratio, protein carbonyl, and IL-6. Significant between-group differences in these variables were also found. Significant changes in anthropometric variables and quality of life were not observed in the study groups. Changes in the level of physical activity were not recorded. Treatment with the active product was well tolerated. All these findings, taken together, support a beneficial effect of supplementation with a mixture of grapefruit, bitter orange fruits, and olive leaf extracts on underlying mechanisms that may interact each other to decrease the cardiovascular risk in healthy people.

Hepatic Lipidomics Analysis Reveals the Antiobesity and Cholesterol-Lowering Effects of Tangeretin in High-Fat Diet-Fed Rats.

Tangeretin (TAN) exhibited antilipogenic, antidiabetic, and lipid-lowering effects. However, the lipid biomarkers and the underlying mechanisms for antiobesity and cholesterol-lowering effects of TAN have not been sufficiently investigated. Herein, we integrated biochemical analysis with lipidomics to elucidate its efficacy and mechanisms in high-fat diet-fed rats. TAN at supplementation levels of 0.04 and 0.08% not only significantly decreased body weight gain, serum total cholesterol, and low-density lipoprotein cholesterol levels but also ameliorated hepatic steatosis. These beneficial effects were associated with the declining levels of fatty acids, diacylglycerols (DGs), triacylglycerols, ceramides, and cholesteryl esters by hepatic lipidomics analysis, which were attributed to downregulating lipogenesis-related genes and upregulating lipid oxidation- and bile acid biosynthesis-related genes. Additionally, 21 lipids were identified as potential lipid biomarkers, such as DGs and phosphatidylethanolamines. These findings indicated that the modulation of lipid homeostasis might be the key pathways for the mechanisms of TAN in the antiobesity and cholesterol-lowering effects.

An evaluation of the genotoxicity and subchronic toxicity of the peel extract of Ponkan cultivar 'Ohta ponkan' (Citrus reticulata Blanco) that is rich in nobiletin and tangeretin with anti-dementia activity.

Nobiletin and tangeretin are major components of polymethoxylated flavones in the peels of citrus fruits such as Citrus reticulata. Because nobiletin and tangeretin have attracted attention due to their beneficial health properties, citrus peel extracts, in which they are concentrated, have the potential to serve as a functional food ingredient to prevent diseases. In this study, a series of toxicological studies on the peel extract of Ponkan cultivar 'Ohta ponkan' (Citrus reticulata Blanco), was conducted. No mutagenic activity was observed in a bacterial reverse mutation test, whereas chromosomal aberrations were induced in an in vitro mammalian chromosomal aberration test. No genotoxicity was observed in an in vivo mammalian micronucleus test. In a 90-day study at daily doses of 54, 180, or 540 mg/kg body weight (bw)/day, hyaline droplet nephropathy, which specifically occurs in adult male rats, was observed in males of 540 mg/kg bw/day group. No other adverse effects were observed in the 90-day study. The no adverse effect level in the 90-day study was considered to be 540 mg/kg bw/day for female rats and less than 540 mg/kg bw/day for male rats.

Effects of glycyrrhizin on the pharmacokinetics of nobiletin in rats and its potential mechanism.

Context: Both nobiletin (NBL) and glycyrrhizin (GL) have anti-inflammatory and antitumor properties. These agents may be co-administered in the clinic. However, the drug-drug interaction between them is not clear.Objective: The drug-drug interaction between GL and NBL was investigated, to clarify the effect of GL on the pharmacokinetics of NBL, and its main mechanism.Materials and methods: The pharmacokinetic profiles of oral administration of NBL (50 mg/kg) in Sprague-Dawley rats of two groups with six each, with or without pre-treatment of GL (100 mg/kg/day for 7 days), were investigated. The effects of GL on the metabolic stability and transport of NBL were also investigated through the rat liver microsome and Caco-2 cell transwell models.Results: The results showed that GL significantly decreased the peak plasma concentration (from 1.74 ± 0.15 to 1.12 ± 0.10 µg/mL) and the t1/2 (7.44 ± 0.65 vs. 5.92 ± 0.68) of NBL, and the intrinsic clearance rate of NBL was increased by the pre-treatment with GL (39.49 ± 2.5 vs. 48.29 ± 3.4 µL/min/mg protein). The Caco-2 cell transwell experiments indicated that GL could increase the efflux ratio of NBL from 1.61 to 2.41.Discussion and conclusion: These results indicated that GL could change the pharmacokinetic profile of NBL, via increasing the metabolism and efflux of NBL in rats. It also suggested that the dose of NBL should be adjusted when co-administrated with GL in the clinic.

Nobiletin Attenuates DSS-Induced Intestinal Barrier Damage through the HNF4α-Claudin-7 Signaling Pathway.

The intestinal epithelium barrier functions to protect human bodies from damages such as harmful microorganisms, antigens, and toxins. In this study, we evaluated the protective effect and molecular mechanism of a dominant polymethoxyflavone nobiletin (NOB) from tangerine peels on intestinal epithelial integrity. The results from transepithelial electrical resistance (TEER) suggested that NOB pretreatment counteracts epithelial injury induced by inflammatory cytokines (TEER value in 48 h: vehicle, 135.6 ± 3.9 Ω/cm2; TNF-α + IL-1ß, 90.7 ± 0.5 Ω/cm2; 10 µM NOB + TNF-α + IL-1ß, 126.1 ± 0.8 Ω/cm2; 100 µM NOB + TNF-α + IL-1ß, 125.3 ± 0.5 Ω/cm2. P < 0.001). Clinical and pathological test results suggested that administration of NOB effectively alleviates intestinal barrier injury induced by dextran sulfate sodium (DSS) as evidenced by the length of colon villi on day 7 (control, 253.7 ± 4.8 µm, DSS 131.6 ± 4.6 µm, NOB + DSS, 234.5 ± 5.1 µm. P < 0.001). Interestingly, when screening tight junction molecules for intestinal barrier integrity, we observed that independent treatment with NOB sharply increased claudin-7 levels (ratio of claudin-7 over GAPDH: control, 1.0 ± 0.06; DSS, 0.02 ± 0.001; NOB + DSS, 0.3 ± 0.07. P < 0.001), which was previously suppressed upon DSS stimulation. Furthermore, hepatocyte nuclear factor 4α (HNF-4α) transcriptional regulation of claudin-7 contributed to intestinal barrier homeostasis. Therefore, our study suggests potential intestinal protective strategies based on polymethoxyflavones of aged tangerine peels.

Nobiletin potentiates paclitaxel anticancer efficacy in A549/T xenograft model: Pharmacokinetic and pharmacological study.

BACKGROUND: Nobiletin (N), a polymethoxylated flavone from citrus fruits, enhanced anti-cancer effects of paclitaxel (PTX) in multi-drug resistance (MDR) cancer cells via inhibiting P-glycoprotein (P-gp) in our previous report. But the in vivo chemo-sensitizing effect of nobiletin is unknown. Moreover, considering the nonlinear pharmacokinetics and narrow therapeutic window of PTX, drug-drug interaction should be explored for using nobiletin with PTX together. PURPOSE: In this study, we wanted to explore whether nobiletin could affect the pharmacokinetic (PK) behavior of PTX and reverse drug resistance in vivo as well as the corresponding mechanisms. STUDY DESIGN AND METHODS: Accurate and sensitive UPLC-MS/MS method was developed for the detection of PTX, and was applied to the pharmacokinetic study in rats. In vivo anti-MDR tumor study was carried out with A549/T xenograft nude mice model. Immunohistochemistry and western blot analysis were used for evaluating the levels of P-gp, Nrf2, and AKT/ERK pathways in MDR tumors. RESULTS: Nobiletin significantly enhanced the therapeutic effects of PTX, and inhibited the MDR tumor sizes in the A549/T xenograft model, while PTX or nobiletin alone did not. We found that nobiletin increased the PTX concentrations in tumor tissues but did not affect the PK behavior of PTX. Notably, Nrf2 and phosphorylation of AKT/ERK expression in MDR tumor tissues were significantly inhibited by giving nobiletin and PTX together. However, nobiletin did not affect the expression of P-gp. CONCLUSION: Nobiletin reversed PTX resistance in MDR tumor via increasing the PTX content in the MDR tumor and inhibiting AKT/ERK/Nrf2 pathways, but without affecting the systematic exposure of PTX, indicating that nobiletin may be an effective and safe MDR tumor reversal agent.

Plant exine capsules based encapsulation strategy: A high loading and long-term effective delivery system for nobiletin.

The properties of high loading capacity and long-term absorption are of great significance in the field of nutraceuticals or drugs delivery. Herein, we developed an innovative method to achieve these expected effects using plant exine capsules, a kind of natural pollen grains, which could provide large internal cavities for loading and robust exine against harsh conditions. In our work, we firstly made a soluble mixture of glycerol monostearate (GM) and nobiletin (NOB) inside the cavities of plant exine capsules by ultrasound with high temperature to obtain a supersaturated state of NOB, which could be characterized by XRD, DSC and FTIR. After that, the loaded capsules were cooled to room temperature. Alginate hydrogels were then selected for encapsulating and further controlling NOB release in simulated gastric and intestinal conditions. As a result, it demonstrated that our approach was able to reach an extremely high NOB loading capacity of 770 ±â€¯40 mg/g using sunflower pollen grains (SPGs). Meanwhile, the existence of GM, SPGs and alginate hydrogels all retarded the release of the NOB synergistically, thus taking a slow release effect in the stomach while a long-term effective absorption in the intestine. Taken together, our processing method of encapsulating hydrophobic nutraceuticals provides an important insight for broadening the applications of nutraceutical or drug encapsulation and delivery.

Enhancing oral absorption of poorly water-soluble herb (Kaempferia parviflora) extract using self-nanoemulsifying formulation.

Kaempferia parviflora, a medicinal herb, treats hypertension and promotes longevity with good health and well-being. Its bioactive component is poorly soluble in water, resulting in poor absorption. This study aimed to enhance the bioavailability of K. parviflora dichloromethane (KPD) extract using a self-nanoemulsifying drug delivery system (SNEDDS). KPD was dissolved in diethylene glycol monoethyl, polyoxyl-35 castor oil and caprylic/capric glyceride, and clear yellow SNEDDS solution was obtained. The methoxyflavone markers were used for content and dissolution analysis. Solid SNEDDS was prepared by stepwise mixing of KPD using a mortar and pestle (1:1 ratio) with five solid carriers: Aerosil® 200, Florite® RE, Neusilin® US2 (NEUS), Fujicalin®, and Neusilin® UFL2. The USP apparatus II with simulated gastric fluid USP (SGF without pepsin, pH 1.2) was used in order to perform the in vitro dissolution. The methoxyflavones dissolution at 60 min from KPD, SEDDS, and SNEDDS/NEUS were approximately 16, 92, and 73%, respectively. The pharmacokinetic profiles of methoxyflavones for oral administration were studied using Wistar rats; the areas under the curve of SNEDDS/NEUS (1.77-fold) and SNEDDS (5.38-fold) were significantly higher than that of KPD. The developed formulations showed good stability after storage for 6 months under accelerated and normal conditions.

Quantitative determination of characteristic components from compound of Lysionotus pauciflorus Maxim. by LC-MS/MS and its application to a pharmacokinetic study.

Tuberculosis of cervical lymph nodes is called scrofula in Traditional Chinese Medicine (TCM). Clinical manifestation is that unilateral or bilateral neck can have multiple enlarged lymph nodes of different sizes. Current therapeutic drugs include Lysionotus pauciflorus Maxim. tablets and compound of Lysionotus pauciflorus Maxim., which have a significant effect on tuberculosis of cervical lymph nodes. This compound is composed of three herbs, Lysionotus pauciflorus Maxim., Prunella vulgaris L. and Artemisia argyi Levl.et Vant. A selective and sensitive LC-MS/MS method was established and validated in rat plasma for the first time. Chromatographic separation was achieved on a Wonda Cract ODS-2 C18 Column (150 mm × 4.6 mm, 5 µm). The mobile phase contained 0.1% formic acid aqueous solution and acetonitrile with a flow rate of 0.8 mL/min. The detection was performed in negative electrospray ionization mode and the precursor/product ion transitions of six components and internal standard (IS) sulfamethoxazole were quantified in multiple reaction monitoring (MRM) using QTRAP-3200 MS/MS. The method fulfilled US Food and Drug Administration guidelines for selectivity, sensitivity, accuracy, precision, matrix effect, extraction recovery, dilution integrity, and stability. This proposed method was then successfully applied to a pharmacokinetic study after oral administration of 10 mL/kg compound extracts in rats. The pharmacokinetic parameters and plasma concentration-time profiles would prove valuable in pre-clinical and clinical investigations on the disposition of compound medicine.

A mixture of citrus polymethoxyflavones, green tea polyphenols and lychee extracts attenuates adipogenesis in 3T3-L1 adipocytes and obesity-induced adipose inflammation in mice.

Adipocyte-macrophage interaction in obesity can cause adipose tissue inflammation and contribute to insulin resistance. Here, we investigated the effect of SlimTrym®-a formulated product containing citrus polymethoxyflavones (PMFs), green tea extract, and lychee polyphenols-on 3T3-L1 adipocyte differentiation and obesity-induced inflammation. SlimTrym® inhibited mitotic clonal expansion (MCE) of 3T3-L1 adipocytes by inducing G1 cell cycle arrest via upregulation of p21 and p53. SlimTrym® attenuated adipogenic differentiation by downregulating adipogenic factors, such as CCAAT-enhancer-binding proteins (C/EBPs) and peroxisome proliferator-activated receptor γ (PPARγ), and upregulating AMP-activated protein kinase (AMPK). Pretreatment with compound C significantly reduced SlimTrym®-mediated suppression of lipid accumulation. SlimTrym® reduced the expression of pro-inflammatory cytokines, including monocyte chemoattractant protein 1 (MCP-1), interleukin (IL)-1ß and IL-6, in co-cultured 3T3-L1 adipocytes and RAW264.7 macrophages. C57BL/6 mice administered with SlimTrym® for 16 weeks showed markedly reduced high-fat diet (HFD)-induced infiltration of monocytes/macrophages in adipose tissue; however, the level of M2 macrophage markers (CD163 and IL-10) was increased. Taken together, these findings indicate that SlimTrym® exerts both anti-adipogenic and anti-inflammatory effects, and can potentially treat obesity and adipose tissue inflammation.

Immunosuppressive effect of hispidulin in allergic contact dermatitis.

BACKGROUND: Long-term use of most immunosuppressants to treat allergic contact dermatitis (ACD) generates unavoidable severe side effects, warranting discovery or development of new immunosuppressants with good efficacy and low toxicity is urgently needed to treat this condition. Hispidulin, a flavonoid compound that can be delivered topically due to its favorable skin penetrability properties, has recently been reported to possess anti-inflammatory and immunosuppressive properties. However, no studies have investigated the effect of hispidulin on Th1 cell activities in an ACD setting. METHODS: A contact hypersensitivity (CHS) mouse model was designed to simulate human ACD. The immunosuppressive effect of hispidulin was investigated via ear thickness, histologic changes (i.e., edema and spongiosis), and interferon-gamma (IFN-γ) gene expression in 1-fluoro-2,4-dinitrobenzene (DNFB)-sensitized mice. Cytotoxicity, total number of CD4+ T cells, and percentage of IFN-γ-producing CD4+ T cells were also investigated in vitro using isolated CD4+ T cells from murine spleens. RESULTS: Topically applied hispidulin effectively inhibited ear swelling (as measured by reduction in ear thickness), and reduced spongiosis, IFN-γ gene expression, and the number of infiltrated immune cells. The inhibitory effect of hispidulin was observed within 6 h after the challenge, and the observed effects were similar to those effectuated after dexamethasone administration. Hispidulin at a concentration up to 50 µM also suppressed IFN-γ-producing CD4+ T cells in a dose-dependent manner without inducing cell death, and without a change in total frequencies of CD4+ T cells among different concentration groups. CONCLUSION: The results of this study, therefore, suggest hispidulin as a novel compound for the treatment of ACD via the suppression of IFN-γ production in Th1 cells.

Pharmacokinetics and drug delivery systems for puerarin, a bioactive flavone from traditional Chinese medicine.

Pueraria lobata (Willd.) Ohwi is a medicinal and edible homologous plant with a long history in China. Puerarin, the main component isolated from the root of Pueraria lobata, possesses a wide range of pharmacological properties. Daidzein and glucuronides are the main metabolites of puerarin and are excreted in the urine and feces. As active substrates of P-gp, multidrug resistance-associated protein and multiple metabolic enzymes, the pharmacokinetics of puerarin can be influenced by different pathological conditions and drug-drug interactions. Due to the poor water-solubility and liposolubility, the applications of puerarin are limited. So far, only puerarin injections and eye drops are on the market. Recent years, researches on improving the bioavailability of puerarin are developing rapidly, various nanotechnologies and preparation technologies including microemulsions and SMEDDS, dendrimers, nanoparticles and nanocrystals have been researched to improve the bioavailability of puerarin. In order to achieve biocompatibility and desired activity, more effective quality evaluations of nanocarriers are required. In this review, we summarize the pharmacokinetics and drug delivery systems of puerarin up to date.

Nanoparticle Encapsulation Strategy: Leveraging Plant Exine Capsules Used as Secondary Capping for Oral Delivery.

Protein-based nanoparticles (NPs) with favorable properties including enhanced absorptivity and low toxicity still suffer a major challenge for rapid nutraceutical or drug release after oral administration. Hence, we introduced a secondary encapsulation for unstable factor to attain a controlled-release effect in a gastrointestinal environment. In this work, assembled nanoparticles engineered by nobiletin (NOB), zein, and tannin acid (TA) were first reported for drug delivery systems. The TA added was capable of obtaining further assembly to stabilize nobiletin in comparison with NOB-loaded zein NPs only. Sunflower pollens (SPGs) were selected as carriers for further oral delivery, while zein was chosen as a coating material for capping SPGs absolutely. As a result, the NOB/zein/TA NPs (NZT NPs) obtained had a stable size of 100 nm after 48 h. Besides, they could improve the chemical stability of NOB for at least 120 days at 4 °C compared with zein NPs (ZT NPs). Owing to the secondary capping by SPGs, the final system was able to release selectively via an oral route, that is, achieving no release in a gastric environment and slow release in an intestine environment. Generally, our research proposed a secondary protection model to prevent drug-loaded NPs from resolving after oral administration, which provided a new perspective for nutraceutical or drug encapsulation and controlled-release delivery.

Oolong Tea Extract and Citrus Peel Polymethoxyflavones Reduce Transformation of l-Carnitine to Trimethylamine-N-Oxide and Decrease Vascular Inflammation in l-Carnitine Feeding Mice.

Carnitine, a dietary quaternary amine mainly from red meat, is metabolized to trimethylamine (TMA) by gut microbiota and subsequently oxidized to trimethylamine-N-oxide (TMAO) by host hepatic enzymes, flavin monooxygenases (FMOs). The objective of this study aims to investigate the effects of flavonoids from oolong tea and citrus peels on reducing TMAO formation and protecting vascular inflammation in carnitine-feeding mice. The results showed that mice treated with 1.3% carnitine in drinking water significantly (p < 0.05) increased the plasma levels of TMAO compared to control group, whereas the plasma TMAO was remarkedly reduced by flavonoids used. Meanwhile, these dietary phenolic compounds significantly (p < 0.05) decreased hepatic FMO3 mRNA levels compared to carnitine only group. Additionally, oolong tea extract decreased mRNA levels of vascular inflammatory markers such as tissue necrosis factor-alpha (TNF-α), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin. Polymethoxyflavones significantly lowered the expression of VCAM-1 and showed a decreasing trend in TNF-α and E-selectin mRNA expression compared to the carnitine group. Genus-level analysis of the gut microbiota in the cecum showed that these dietary phenolic compounds induced an increase in the relative abundances of Bacteroides. Oolong tea extract-treated group up-regulated Lactobacillus genus, compared to the carnitine only group. Administration of polymethoxyflavones increased Akkermansia in mice.