Pharmacokinetics and tissue distribution of 5,7-dimethoxyflavone in mice following single dose oral administration

Tissue distribution and pharmacokinetics of isoxanthohumol from hops in rodents

Vegetables and fruits contain prenylflavonoids with biological functions that might improve human health. The prenylflavonoid isoxanthohumol (IXA) and its derivative, 8-prenylnaringenin (8-PN), have beneficial activities, including anti-cancer effects and suppression of insulin resistance. However, their pharmacokinetic profile is unclear. Previous studies suggested flavonoids have low systemic availability and are excreted via the feces. Therefore, this study investigated the tissue distribution dynamics of high-purity IXA (>90%) from hops administered orally, either singly (50 mg/kg body weight [BW]) or daily for 14 days (30 mg/kg BW), to mice. High-pressure liquid chromatography demonstrated that IXA was absorbed rapidly after a single administration and reached plasma maximum concentration (C max) (3.95 ± 0.81 μmol/L) by 0.5 h. IXA was present at high levels in the liver compared with the kidney, pancreas, lung, skeletal muscle, spleen, thymus, and heart. The highest IXA level after 14 days of IXA ingestion was observed in the liver, followed by the kidney, thymus, spleen, lung, and brain. There was no significant difference in IXA accumulation in tissues between the single and multiple dose groups. Analyses of the livers of rats treated with different concentrations of IXA (112.5-1500 mg/kg BW) once a day for 28 days demonstrated that IXA accumulated dose-dependently with a correlation coefficient of .813. The accumulation of 8-PN was dependent on the intake period but not the intake amount of IXA (correlation coefficient -.255). In summary, IXA and 8-PN were detected in tissues and organs up to 24 h after ingestion, suggesting that orally ingested IXA might have health benefits as a nutraceutical.

A sulfonamide chalcone inhibited dengue virus with a potential target at the SAM-binding site of viral methyltransferase

Dengue infection is a global health problem as climate change facilitates the spread of mosquito vectors. Infected patients could progress to severe plasma leakage and hemorrhagic shock, where current standard treatment remains supportive. Previous reports suggested that several flavonoid derivatives inhibited mosquito-borne flaviviruses. This work aimed to explore sulfonamide chalcone derivatives as dengue inhibitors and to identify molecular targets. We initially screened 27 sulfonamide chalcones using cell-based antiviral and cytotoxic screenings. Two potential compounds, SC22 and SC27, were identified with DENV1-4 EC50s in the range of 0.71-0.94 and 3.15-4.46 μM, and CC50s at 14.63 and 31.02 μM, respectively. The compounds did not show any elevation in ALT or Cr in C57BL/6 mice on the 1st, 3rd, and 7th days after being administered intraperitoneally with 50 mg/kg SC22 or SC27 in a single dose. Moreover, the SAM-binding site of NS5 methyltransferase was a potential target of SC27 identified by computational and enzyme-based assays. The main target of SC22 was in a late stage of viral replication, but the exact target molecule had yet to be identified. In summary, a sulfonamide chalcone, SC27, was a potential DENV inhibitor that targeted viral methyltransferase. Further investigation should be the study of the structure-activity relationship of SC27 derivatives for higher potency and lower toxicity.

The 8-bromobaicalein alleviated chikungunya-induced musculoskeletal inflammation and reduced the viral load in healthy adult mice

Chikungunya virus is a re-emerging arbovirus that has caused epidemic outbreaks in recent decades. Patients in older age groups with high viral load and severe immunologic response during acute infection are likely to develop chronic arthritis and severe joint pain. Currently, no antiviral drug is available. Previous studies suggested that a flavone derivative, 8-bromobaicalein, was a potential dengue and Zika replication inhibitor in a cell-based system targeting flaviviral polymerase. Here we characterized that 8-bromobaicalein inhibited chikungunya virus replication with EC50 of 0.49 ± 0.11 µM in Vero cells. The molecular target predicted at viral nsP1 methyltransferase using molecular binding and fragment molecular orbital calculation. Additionally, oral administration of 250 mg/kg twice daily treatment alleviated chikungunya-induced musculoskeletal inflammation and reduced viral load in healthy adult mice. Pharmacokinetic analysis indicated that the 250 mg/kg administration maintained the compound level above EC99.9 for 12 h. Therefore, 8-bromobaicalein should be a potential candidate for further development as a pan-arboviral drug.

Kaempferia parviflora Extracts Protect Neural Stem Cells from Amyloid Peptide-Mediated Inflammation in Co-Culture Model with Microglia

The existence of neuroinflammation and oxidative stress surrounding amyloid beta (Aβ) plaques, a hallmark of Alzheimer's disease (AD), has been demonstrated and may result in the activation of neuronal death and inhibition of neurogenesis. Therefore, dysregulation of neuroinflammation and oxidative stress is one possible therapeutic target for AD. Kaempferia parviflora Wall. ex Baker (KP), a member of the Zingiberaceae family, possesses health-promoting benefits including anti-oxidative stress and anti-inflammation in vitro and in vivo with a high level of safety; however, the role of KP in suppressing Aβ-mediated neuroinflammation and neuronal differentiation has not yet been investigated. The neuroprotective effects of KP extract against Aβ₄₂ have been examined in both monoculture and co-culture systems of mouse neuroectodermal (NE-4C) stem cells and BV-2 microglia cells. Our results showed that fractions of KP extract containing 5,7-dimethoxyflavone, 5,7,4'-trimethoxyflavone, and 3,5,7,3',4'-pentamethoxyflavone protected neural stem cells (both undifferentiated and differentiated) and microglia activation from Aβ₄₂-induced neuroinflammation and oxidative stress in both monoculture and co-culture system of microglia and neuronal stem cells. Interestingly, KP extracts also prevented Aβ₄₂-suppressed neurogenesis, possibly due to the contained methoxyflavone derivatives. Our data indicated the promising role of KP in treating AD through the suppression of neuroinflammation and oxidative stress induced by Aβ peptides.

The Chemistry and the Anti-Inflammatory Activity of Polymethoxyflavonoids from Citrus Genus

Polymethoxyflavonoids (PMFs) are a large group of compounds belonging to the more general class of flavonoids that possess a flavan carbon framework decorated with a variable number of methoxy groups. Hydroxylated polymethoxyflavonoids (HPMFs), instead, are characterized by the presence of both hydroxyl and methoxy groups in their structural unities. Some of these compounds are the aglycone part in a glycoside structure in which the glycosidic linkage can involve the -OH at various positions. These compounds are particular to Citrus genus plants, especially in fruits, and they are present mainly in the peel. A considerable number of PMFs and HPMFs have shown promising biological activities and they are considered to be important nutraceuticals, responsible for some of the known beneficial effects on health associated with a regular consumption of Citrus fruits. Among their several actions on human health, it is notable that the relevant contribution in controlling the intracellular redox imbalance is associated with the inflammation processes. In this work, we aim to describe the status concerning the chemical identification and the anti-inflammatory activity of both PMFs and HPMFs. In particular, all of the chemical entities unambiguously identified by isolation and complete NMR analysis, and for which a biochemical evaluation on the pure compound was performed, are included in this paper.

Biotransformation of 5,7-Methoxyflavones by Selected Entomopathogenic Filamentous Fungi

5,7-Dimethoxyflavone, a chrysin derivative, occurs in many plants and shows very low toxicity, even at high doses. On the basis of this phenomenon, we biotransformed a series of methoxy-derivatives of chrysin, apigenin, and tricetin obtained by chemical synthesis. We used entomopathogenic fungal strains with the confirmed ability of simultaneous hydroxylation/demethylation and glycosylation of flavonoid compounds. Both the amount and the place of attachment of the methoxy group influenced the biotransformation rate and the product's amount nascent. Based on product and semi-product structures, it can be concluded that they are the result of cascading transformations. Only in the case of 5,7,3',4',5'-pentamethoxyflavone, the strains were able to attach a sugar molecule in place of the methoxy substituent to give 3'-O-β-d-(4″-O-methylglucopyranosyl)-5,7,4',5'-tetramethoxyflavone. However, we observed the tested strains' ability to selectively demethylate/hydroxylate the carbon C-3' and C-4' of ring B of the substrates used. The structures of four hydroxyl-derivatives were determined: 4'-hydroxy-5,7-dimethoxyflavone, 3'-hydroxy-5,7-dimethoxyflavone, 3'-hydroxy-5,7,4',5'-tetramethoxyflavone, and 5,7-dimethoxy-3',4'-dihydroxyflavone (5,7-dimethoxy-luteolin).

Polymethoxyflavone purified from Kaempferia parviflora reduces visceral fat in Japanese overweight individuals: a randomised, double-blind, placebo-controlled study

Visceral fat is a more important factor in obesity-associated disorders in Japanese individuals than in Caucasian individuals. The objective of this randomised, double-blind, placebo-controlled parallel group study, conducted in Japanese overweight adults, was to investigate the effects of polymethoxyflavone purified from Kaempferia parviflora on visceral fat. A total of 80 subjects (aged 20-64 years, 23.0 ≤ body mass index < 30 kg m-2) were randomly assigned in 1 : 1 ratio to either the active (polymethoxyflavone purified from K. parviflora) or placebo group. Over a 12-week period, each subject received two capsules containing polymethoxyflavone purified from K. parviflora (12 mg polymethoxyflavone per day) or placebo. The primary outcome was a reduction in visceral fat area (VFA), while the secondary outcome was a reduction in subcutaneous fat area (SFA) and total fat area (TFA). VFA was measured at 0, 8, and 12 weeks using computed tomography scanning. Results showed that VFA significantly reduced after 12 weeks in the active group and was significantly lower than in the placebo group at 8 and 12 weeks. A significant reduction was observed in SFA and TFA after 8 and 12 weeks in the active group; TFA was significantly lower than that in the placebo group at 8 and 12 weeks. No adverse events associated with the test supplements were observed in either group. Our study shows that administration of polymethoxyflavone purified from K. parviflora reduces visceral fat in Japanese overweight adults.

Biopolymer Additives Enhance Tangeretin Bioavailability in Emulsion-Based Delivery Systems: An In Vitro and In Vivo Study

The oral bioavailability of tangeretin, a poly(methoxyflavone) found in citrus fruits, is typically very low because of its extremely limited solubility. In this research, tangeretin was encapsulated within whey protein-stabilized emulsions containing ingredients that may alter their behavior under gastrointestinal conditions and enhance the bioavailability of tangeretin after oral administration: cinnamaldehyde (CA), gum arabic (GA), or hydroxypropyl methylcellulose (HPMC). The presence of these ingredients altered the size, aggregation state, and encapsulation efficiency of tangeretin in the emulsions. In vitro studies demonstrated that the bioaccessibility of the encapsulated tangeretin was much higher than that of a crude tangeretin oil suspension. Particularly, the addition of HPMC increased the bioaccessibility of tangeretin from around 36 to 90%. In vivo pharmacokinetics results using rats indicated that tangeretin concentration in the plasma increased from 4- to 20-fold after encapsulation, especially in the presence of HPMC. HPMC also prolonged the release of tangeretin to 22 h. Tangeretin preferentially accumulated within the liver and kidney of the animals. Overall, the knowledge confirmed that structured emulsion-based delivery systems could be used to improve the oral bioavailability of hydrophobic functional ingredients.

The 5,7-Dimethoxyflavone Suppresses Sarcopenia by Regulating Protein Turnover and Mitochondria Biogenesis-Related Pathways

Sarcopenia is a muscle disease featured by the loss of muscle mass and dysfunction with advancing age. The 5,7-dimethoxyflavone (DMF), a major flavone found in Kaempferia parviflora, has biological activities, including anti-diabetes, anti-obesity, and anti-inflammation. However, its anti-sarcopenic effect remains to be elucidated. This current study investigated the inhibitory activity of DMF on sarcopenia. Eighteen-month-old mice were orally administered DMF at the dose of 25 mg·kg⁻¹·day⁻¹ or 50 mg·kg⁻¹·day⁻¹ for 8 weeks. DMF not only stimulated grip strength and exercise endurance but also increased muscle mass and volume. Besides, DMF stimulated the phosphatidylinositol 3-kinase-Akt pathway, consequently activating the mammalian target of rapamycin-eukaryotic initiation factor 4E-binding protein 1-70-kDa ribosomal protein S6 kinase pathway for protein synthesis. DMF reduced the mRNA expression of E3 ubiquitin ligase- and autophagy-lysosomal-related genes involved in proteolysis via the phosphorylation of Forkhead box O3. DMF upregulated peroxisome proliferator-activated receptor-gamma coactivator 1 alpha, nuclear respiratory factor 1, and mitochondrial transcription factor A along with the increase of relative mitochondrial DNA content. DMF alleviated inflammatory responses by reducing the tumor necrosis factor-alpha and interleukin-6 serum and mRNA levels. Collectively, DMF can be used as a natural agent to inhibit sarcopenia via improving protein turnover and mitochondria function.

Pharmacokinetics of B-Ring Unsubstituted Flavones

B-ring unsubstituted flavones (of which the most widely known are chrysin, baicalein, wogonin, and oroxylin A) are 2-phenylchromen-4-one molecules of which the B-ring is devoid of any hydroxy, methoxy, or other substituent. They may be found naturally in a number of herbal products used for therapeutic purposes, and several have been designed by researchers and obtained in the laboratory. They have generated interest in the scientific community for their potential use in a variety of pathologies, and understanding their pharmacokinetics is important for a grasp of their optimal use. Based on a comprehensive survey of the relevant literature, this paper examines their absorption (with deglycosylation as a preliminary step) and their fate in the body, from metabolism to excretion. Differences among species (inter-individual) and within the same species (intra-individual) variability have been examined based on the available data, and finally, knowledge gaps and directions of future research are discussed.

Kaempferia parviflora Ethanol Extract, a Peroxisome Proliferator-Activated Receptor γ Ligand-binding Agonist, Improves Glucose Tolerance and Suppresses Fat Accumulation in Diabetic NSY Mice

This study assessed the effect of Kaempferia parviflora, also known as black ginger (BG), and its ethanol extract (BGE) on peroxisome proliferator-activated receptor (PPAR) γ agonistic activity, glucose tolerance, fat accumulation, and lipids-induced hypertriglyceridemia in mice. PPARγ ligand-binding capacity in vitro and polymethoxy flavone contents were highly observed in organic solvent extracts. In an animal experiment A, male diabetic Nagoya-Shibata-Yasuda mice were divided into five dietary groups and fed each diet for 8 weeks: AIN-93G diet (low-fat [LF] diet), high-fat (HF) diet, HF diet supplemented with 1% BG, HF diet supplemented with 0.19% BGE, and HF diet supplemented with pioglitazone (PPARγ agonist, 3 mg/kg/day) as a PPARγ agonistic positive control. As determined from glucose and insulin tolerance tests, plasma glucose levels were improved in the BG and BGE groups. The BGE extract suppressed fat accumulation in adipose tissues, liver, and muscles without changing the plasma adiponectin level. In an animal experiment B, in order to investigate the effect of BG and BGE on lipid-induced hypertriglyceridemia, male ddY mice were divided into three test groups: control, BG-administered group (500 mg/kg), and BGE-administered group (100 mg/kg). The plasma triacylglycerol level was not different among the groups during the lipids administration test. These results conclude that the BGE extract containing several kinds of polymethoxy flavones showed PPARγ ligand-binding capacity in vitro and prevented obesity and insulin resistance independent of adiponectin secretion in mice. PRACTICAL APPLICATION: Kaempferia parviflora, also known as black ginger (BG), is often used as a folk medicine and a functional food material to prevent metabolic syndrome mainly in Asian regions. Here, we have clarified that ethanol extract from BG (BGE) contains several kinds of polymethoxy flavones to show PPARγ ligand-binding capacity and is an active extract for the improvement of obesity and insulin resistance. The BGE is expected to be applied for functional food materials in health food markets. Also, polymethoxy flavones to show PPARγ ligand-binding capacity can be generally applied as a physiological active compound of functional food supplements.

Pharmacokinetics, bioavailability, tissue distribution and excretion of tangeretin in rat

Tangeretin, 4′,5,6,7,8-pentamethoxyflavone, is one of the major polymethoxyflavones (PMFs) existing in citrus fruits, particularly in the peels of sweet oranges and mandarins. Tangeretin has been reported to possess several beneficial bioactivities including anti-inflammatory, anti-proliferative and neuroprotective effects. To achieve a thorough understanding of the biological actions of tangeretin in vivo, our current study is designed to investigate the pharmacokinetics, bioavailability, distribution and excretion of tangeretin in rats. After oral administration of 50 mg/kg bw tangeretin to rats, the C_max, T_max and t_1/2 were 0.87 ± 0.33 μg/mL, 340.00 ± 48.99 min and 342.43 ± 71.27 min, respectively. Based on the area under the curves (AUC) of oral and intravenous administration of tangeretin, calculated absolute oral bioavailability was 27.11%. During tissue distribution, maximum concentrations of tangeretin in the vital organs occurred at 4 or 8 h after oral administration. The highest accumulation of tangeretin was found in the kidney, lung and liver, followed by spleen and heart. In the gastrointestinal tract, maximum concentrations of tangeretin in the stomach and small intestine were found at 4 h, while in the cecum, colon and rectum, tangeretin reached the maximum concentrations at 12 h. Tangeretin excreted in the urine and feces was recovered within 48 h after oral administration, concentrations were only 0.0026% and 7.54%, respectively. These results suggest that tangeretin was mainly eliminated as metabolites. In conclusion, our study provides useful information regarding absorption, distribution, as well as excretion of tangeretin, which will provide a good base for studying the mechanism of its biological effects.

Effect of the active ingredient of Kaempferia parviflora, 5,7-dimethoxyflavone, on the pharmacokinetics of midazolam

5,7-Dimethoxyflavone (5,7-DMF), one of the major components of Kaempferia parviflora, has anti-obesity, anti-inflammatory, and antineoplastic effects. On the other hand, in vitro studies have reported that it directly inhibits the drug metabolizing enzyme family cytochrome P450 (CYP) 3As. In this study, its safety was evaluated from a pharmacokinetic point of view, based on daily ingestion of 5,7-DMF. Midazolam, a substrate of CYP3As, was orally administered to mice treated with 5,7-DMF for 10 days, and its pharmacokinetic properties were investigated. In the group administered 5,7-DMF, the area under the curve (AUC) of midazolam increased by 130% and its biological half-life was extended by approximately 100 min compared to the control group. Compared to the control group, 5,7-DMF markedly decreased the expression of CYP3A11 and CYP3A25 in the liver. These results suggest that continued ingestion of 5,7-DMF decreases the expression of CYP3As in the liver, consequently increasing the blood concentrations of drugs metabolized by CYP3As.

Effect of 5,7-dimethoxyflavone on Bcrp1-mediated transport of sorafenib in vitro and in vivo in mice

Tyrosine kinase inhibitors (TKI) are a novel and target-specific class of anticancer drugs. One drawback of TKI therapy is cancer resistance to TKI. An important TKI resistance mechanism is enhanced efflux of TKI by efflux transporters, such as Breast Cancer Resistance Protein (BCRP), in cancer cells. 5,7-Dimethoxyflavone (5,7-DMF) is a natural flavonoid which was recently reported to be a potent BCRP inhibitor. In the current study, the effect of 5,7-DMF on the disposition of sorafenib, a TKI which is a good substrate of BCRP, was investigated both in vitro in efflux transporter expressing cells and in vivo in mice. 5,7-DMF significantly inhibited Bcrp1-mediated sorafenib efflux in a concentration dependent manner in MDCK/Bcrp1 cells, with EC₅₀ value of 8.78 μM. The pharmacokinetics and tissue distribution of sorafenib (10 mg/kg) with and without co-administration of 75 mg/kg 5,7-DMF were determined. With 5,7-DMF, the AUC of sorafenib in plasma was 47,400 ± 4790 ng·h/mL, which was significantly higher than 27,300 ± 2650 ng·h/mL in sorafenib alone group. In addition, compared to sorafenib alone group, great increase in sorafenib AUC was observed in most tissues collected when sorafenib was given with 5,7-DMF. Our results indicated that 5,7-DMF may represent a novel and very promising chemosensitizing agent for BCRP-mediated anticancer drug resistance due to its low toxicity and potent BCRP inhibition.