An HPLC-MS/MS method for the simultaneous determination of luteolin and its major metabolites in rat plasma and its application to a pharmacokinetic study

Luteolin as a potential therapeutic candidate for lung cancer: Emerging preclinical evidence

Lung cancer is a prevalent malignant tumor and a leading cause of cancer-related fatalities globally. However, current treatments all have limitations. Therefore, there is an urgent need to identify a readily available therapeutic agent to counteract lung cancer development and progression. Luteolin is a flavonoid derived from vegetables and herbs that possesses preventive and therapeutic effects on various cancers. With the goal of providing new directions for the treatment of lung cancer, we review here the recent findings on luteolin so as to provide new ideas for the development of new anti-lung cancer drugs. The search focused on studies published between January 1995 and January 2024 that explored the use of luteolin in lung cancer. A comprehensive literature search was conducted in the SCOPUS, Google Scholar, PubMed, and Web of Science databases using the keywords "luteolin" and "lung cancer." By collecting previous literature, we found that luteolin has multiple mechanisms of therapeutic effects, including promotion of apoptosis in lung cancer cells; inhibition of tumor cell proliferation, invasion and metastasis; and modulation of immune responses. In addition, it can be used as an adjuvant to radio-chemotherapy and helps to ameliorate cancer complications. This review summarizes the structure, natural sources, physicochemical properties and pharmacokinetics of luteolin, and focuses on the anti-lung cancer mechanism of luteolin, so as to provide new ideas for the development of new anti-lung cancer drugs.

Analysis of Lemon Verbena Polyphenol Metabolome and Its Correlation with Oxidative Stress under Glucotoxic Conditions in Adipocyte

Lemon verbena has been shown to ameliorate obesity-related oxidative stress, but the intracellular final effectors underlying its antioxidant activity are still unknown. The purpose of this study was to correlate the antioxidant capacity of plasma metabolites of lemon verbena (verbascoside, isoverbascoside, hydroxytyrosol, caffeic acid, ferulic acid, homoprotocatechuic acid, and luteolin-7-diglucuronide) with their uptake and intracellular metabolism in hypertrophic adipocytes under glucotoxic conditions. To this end, intracellular ROS levels were measured, and the intracellular metabolites were identified and quantified by high-performance liquid chromatography with a diode array detector coupled to mass spectrometry (HPLC-DAD-MS). The results showed that the plasma metabolites of lemon verbena are absorbed by adipocytes and metabolized through phase II reactions and that the intracellular appearance of these metabolites correlates with the decrease in the level of glucotoxicity-induced oxidative stress. It is postulated that the biotransformation and accumulation of these metabolites in adipocytes contribute to the long-term antioxidant activity of the extract.

Luteolin as a potential hepatoprotective drug: Molecular mechanisms and treatment strategies

Luteolin is a flavonoid widely present in various traditional Chinese medicines. In recent years, luteolin has received more attention due to its impressive liver protective effect, such as metabolic associated fatty liver disease, hepatic fibrosis and hepatoma. This article summarizes the pharmacological effects, pharmacokinetic characteristics, and toxicity of luteolin against liver diseases, and provides prospect. The results indicate that luteolin improves liver lesions through various mechanisms, including inhibiting inflammatory factors, reducing oxidative stress, regulating lipid balance, slowing down excessive aggregation of extracellular matrix, inducing apoptosis and autophagy of liver cancer cells. Pharmacokinetics research manifested that due to metabolic effects, the bioavailability of luteolin is relatively low. It is worth noting that appropriate modification, new delivery systems, and derivatives can enhance its bioavailability. Although many studies have shown that the toxicity of luteolin is minimal, strict toxicity experiments are still needed to evaluate its safety and promote its reasonable development. In addition, this study also discussed the clinical applications related to luteolin, indicating that it is a key component of commonly used liver protective drugs in clinical practice. In view of its excellent pharmacological effects, luteolin is expected to become a potential drug for the treatment of various liver diseases.

Rapid classification and identification of chemical constituents in Leonurus japonicus Houtt based on UPLC-Q-Orbitrap-MS combined with data post-processing techniques

Leonurus japonicus Houtt (LJH) is a bulk medicinal material commonly used in clinical practice, but its complex constituents have not been completely understood, posing challenges to pharmacology, pharmacokinetic research, and scientific and rational drug use. As a result, it is critical to develop an efficient and accurate method for classifying and identifying the chemical composition of LJH. In this study, ultra-performance liquid chromatography-quadrupole electrostatic field-orbital trap high resolution mass spectrometry (UPLC-Q-Orbitrap-MS) was successfully established, along with two data post-processing techniques, characteristic fragmentations (CFs) and neutral losses (NLs), to quickly classify and identify the chemical constituents in LJH. As a result, 44 constituents of LJH were identified, including four alkaloids, 20 flavonoids, two phenylpropanoids, 17 organic acids, and one amino acid. The method in this paper enables classification and identification of chemical compositions rapidly, providing a scientific foundation for further research on the effective and toxic substances of LJH.

Optimized Chitosan-Based Nanoemulsion Improves Luteolin Release

Luteolin (LUT) is a flavonoid found in several edible and medicinal plants. It is recognized for its biological activities such as antioxidant, anti-inflammatory, neuroprotective, and antitumor effects. However, the limited water solubility of LUT leads to poor absorption after oral administration. Nanoencapsulation may improve the solubility of LUT. Nanoemulsions (NE) were selected for the encapsulation of LUT due to their biodegradability, stability, and ability to control drug release. In this work, chitosan (Ch)-based NE was developed to encapsulate luteolin (NECh-LUT). A 2³ factorial design was built to obtain a formulation with optimized amounts of oil, water, and surfactants. NECh-LUT showed a mean diameter of 67.5 nm, polydispersity index 0.174, zeta potential of +12.8 mV, and encapsulation efficiency of 85.49%. Transmission electron microscopy revealed spherical shape and rheological analysis verified the Newtonian behavior of NECh-LUT. SAXS technique confirmed the bimodal characteristic of NECh-LUT, while stability analysis confirmed NECh-LUT stability when stored at room temperature for up to 30 days. Finally, in vitro release studies showed LUT controlled release up to 72 h, indicating the promising potential of NECh-LUT to be used as novel therapeutic option to treat several disorders.

Apple polyphenol biotransformation using probiotics in vitro and dynamic simulated digestion by bionic rats

BACKGROUND

The present study investigated the effects of fermentation by Lactobacillus rhamnosus zrx01 (LR-zrx01), Lactobacillus acidophilus zrx02 (LA-zrx02), and Lactobacillus plantarum zrx03 (LP-zrx03), as well as dynamic simulated digestion by bionic rats, on the biotransformation and antioxidant potential of apple polyphenols. Polyphenols were determined by ultra-high-performance liquid chromatography-mass spectrometry, the dynamic simulated digestion of fermented apple pulp was determined by bionic rats, and the antibacterial and antioxidant activities were analyzed.

RESULTS

The polyphenol content of apple pulp fermented using the three strains was respectively 1.41, 1.38, and 1.36 times that of non-fermented pulp. The antibacterial activity of apple pulp improved dramatically after fermentation. Moreover, the antioxidant potential of apple pulp increased after fermentation and digestion. After dynamic simulated digestion by bionic rats, the polyphenol content in unfermented and the three fermented groups increased significantly by 1.19, 1.23, 1.20, and 1.19 times compared to that before digestion, respectively. The major polyphenols in each group with obvious changes were epicatechin, rutin, kaempferol, quercetin-3 galactoside, p-coumaric acid, and two unknown substances, 1 and 2.

CONCLUSION

Fermented and digested apple polyphenols showed better biotransformation effects and mostly existed in the form of small molecules, which was conducive to the improvement of polyphenol bioavailability and beneficial to the absorption of active substances by the human body. These findings build a foundation for the development of functional food beverages. © 2023 Society of Chemical Industry.

Luteolin, a Potent Anticancer Compound: From Chemistry to Cellular Interactions and Synergetic Perspectives

Increasing rates of cancer incidence and the toxicity concerns of existing chemotherapeutic agents have intensified the research to explore more alternative routes to combat tumor. Luteolin, a flavone found in numerous fruits, vegetables, and herbs, has exhibited a number of biological activities, such as anticancer and anti-inflammatory. Luteolin inhibits tumor growth by targeting cellular processes such as apoptosis, cell-cycle progression, angiogenesis and migration. Mechanistically, luteolin causes cell death by downregulating Akt, PLK-1, cyclin-B1, cyclin-A, CDC-2, CDK-2, Bcl-2, and Bcl-xL, while upregulating BAX, caspase-3, and p21. It has also been reported to inhibit STAT3 signaling by the suppression of STAT3 activation and enhanced STAT3 protein degradation in various cancer cells. Therefore, extensive studies on the anticancer properties of luteolin reveal its promising role in chemoprevention. The present review describes all the possible cellular interactions of luteolin in cancer, along with its synergistic mode of action and nanodelivery insight.

Conduction of a chemical structure-guided metabolic phenotype analysis method targeting phenylpropane pathway via LC-MS: Ginkgo biloba and soybean as examples

The phenylpropane pathway (PPP) is one of the most extensively investigated metabolic routes. This pathway biosynthesizes many important active ingredients such as phenylpropanoids and flavonoids that affect the flavor, taste and nutrients of food. How to elucidate the metabolic phenotype of PPP is fundamental in food research and development. In this study, we designed a structural periodical table filled with 103 metabolites produced from PPP. All of them especially the 62 structural isomers were qualified and quantified with high resolution and sensitivity via multiple reaction mode in liquid chromatography tandem triple quadrupole mass spectrometry. Ginkgo biloba and soybean were used as samples for the practical application of this method: The delicate spatial-temporal metabolic balance of PPP from ginkgo biloba has been first elucidated; It is first confirmed that the salt and draught stresses could redirect the biosynthesis trend of PPP to produce more isoflavones in soybean leaves.

Mucoadhesive nanoemulsion enhances brain bioavailability of luteolin after intranasal administration and induces apoptosis to sh-sy5y neuroblastoma cells

Neuroblastoma is the most frequently diagnosed extracranial solid tumor in children and accounts for 7% of all childhood malignancies and 15% cancer mortality in children. Luteolin (LUT) is recognized by its anticancer activity against several types of cancer. The aim of this study was to prepare chitosan-coated nanoemulsion containing luteolin (NECh-LUT), investigate its potential for brain delivery following intranasal administration, and to evaluate its cytotoxicity against neuroblastoma cells. NECh-LUT was developed by cavitation process and characterized for its size, surface charge, encapsulation efficiency, and mucoadhesion. The developed formulation presented size 68±1 nm, zeta potential +13±1 mV, and encapsulation efficiency of 85.5±0.3%. The NECh-LUT presented nearly 6-fold higher permeation through the nasal mucosa ex vivo and prolonged LUT release up to 72 h in vitro, following Baker-Lonsdale kinetic model. The pharmacokinetic evaluation of NECh-LUT revealed a 10-fold increase in drug half-life and a 4.4 times enhancement in LUT biodistribution in brain tissue after intranasal administration of single-dose. In addition, NECh-LUT inhibited the growth of neuroblastoma cells after 24, 48 and 72 h in concentrations starting from 2 µM. The NECh-LUT developed for intranasal administration proved to be a promising alternative for brain delivery of LUT, and a viable option for the treatment of neuroblastoma.

Novel luteolin@pro-phytomicelles: In vitro characterization and in vivo evaluation of protection against drug-induced hepatotoxicity

A novel nanoformulation with the small molecule phytochemical dipotassium glycyrrhizinate as a nanomaterial was developed for the oral delivery of luteolin (Lut), a widely used phytochemical, but it suffered from poor water solubility and low oral bioavailability. This novel nanoformulation, named Lut@pro-phytomicelles, can be fabricated with a simple process. Lut@pro-phytomicelles can instantly dissolve into aqueous mediums and formulate through self-assembly a clear phytomicelle solution with a Lut encapsulation efficiency of 99.16 ± 0.90%, a small micelle size of 30.32 ± 0.12 nm, and a narrow polydispersity index of 0.138 ± 0.024. The optimized formulation demonstrated that Lut had solubility in up to 50 mg/ml of water as a result of its encapsulation within DG phytomicelles. Lut@pro-phytomicelles exhibited excellent characteristics, including good storage stability, a fast in vitro release profile, improvement in in vitro antioxidant activity, and high safety potential. In the oral bioavailability evaluation, a shorter Tmax, increased Cmax, and improved AUC0-t were obtained with Lut@pro-phytomicelles when compared to bare Lut. The distribution evaluation further showed that Lut@pro-phytomicelles could effectively increase the concentrations of Lut in all the tested organs and gastrointestinal segments. In the protection efficacy evaluation, 100 mg/kg Lut@pro-phytomicelles demonstrated strong effects against acetaminophen-induced hepatotoxicity. The mechanisms of inhibiting high-mobility group box 1 signaling and suppressing oxidative stress were involved in this strong treatment effect. These results showed that simple but novel Lut@pro-phytomicelles provided a new, promising nano-delivery system for Lut with a significantly improved in vivo profile.

Spatial Distribution of Polyphenolic Compounds in Corn Grains (Zea mays L. var. Pioneer) Studied by Laser Confocal Microscopy and High-Resolution Mass Spectrometry

Desirable changes in the biochemical composition of food plants is a key outcome of breeding strategies. The subsequent localization of nutritional phytochemicals in plant tissues gives important information regarding the extent of their synthesis across a tissue. We performed a detailed metabolomic analysis of phytochemical substances of grains from Zea mays L. (var. Pioneer) by tandem mass spectrometry and localization by confocal microscopy. We found that anthocyanins are located mainly in the aleurone layer of the grain. High-performance liquid chromatography in combination with ion trap tandem mass spectrometry revealed the presence of 56 compounds, including 30 polyphenols. This method allows for effective and rapid analysis of anthocyanins by plotting their distribution in seeds and grains of different plants. This approach will permit a more efficient screening of phenotypic varieties during food plant breeding.

Dracocephalum palmatum S. and Dracocephalum ruyschiana L. Originating from Yakutia: A High-Resolution Mass Spectrometric Approach for the Comprehensive Characterization of Phenolic Compounds

Dracocephalum palmatum S. and Dracocephalum ruyschiana L. contain a large number of target analytes, which are biologically active compounds. High performance liquid chromatography (HPLC) in combination with an ion trap (tandem mass spectrometry) was used to identify target analytes in extracts of D. palmatum S. and D. ruyschiana L. originating from Yakutia. The results of initial studies revealed the presence of 114 compounds, of which 92 were identified for the first time in the genus Dracocephalum. New identified metabolites belonged to 17 classes, including 16 phenolic acids and their conjugates, 18 flavones, 5 flavonols, 2 flavan-3-ols, 1 flavanone, 2 stilbenes, 10 anthocyanins, 1 condensed tannin, 2 lignans, 6 carotenoids, 3 oxylipins, 2 amino acids, 3 sceletium alkaloids, 3 carboxylic acids, 8 fatty acids, 1 sterol, and 3 terpenes, along with 6 miscellaneous compounds. It was shown that extracts of D. palmatum are richer in the spectrum of polyphenolic compounds compared with extracts of D. ruyschiana, according to a study of the presence of these compounds in extracts, based on the results of mass spectrometric studies.

Integrated Phytochemical Analysis Based on UPLC-MS/MS and Network Pharmacology Approaches to Explore the Effect of Odontites vulgaris Moench on Rheumatoid Arthritis

Odontites vulgaris Moench has the effect of clearing away heat, detoxification, dispelling wind, and clearing dampness. In this study, the potential anti-inflammatory compounds of O. vulgaris were investigated using ultra-high-performance liquid chromatography-mass spectrometry (UPLC-MS/MS) combined with the network pharmacology approach and further confirmed on an LPS-activated RAW 264.7 macrophage model. Monomer compounds were prepared from the active fraction using modern advanced separation and purification methods. UPLC-Q-Exactive HRMS was used to identify the chemical compounds in the active fractions of O. vulgaris. D-mannitol, geniposidic acid, salidroside, shanzhiside methyl ester, eleutheroside B, geniposide, 7,8-dihydroxycoumarin, gardoside methyl ester, arenarioside, vanillic acid, p-hydroxy-cinnamic acid, melampyroside, syringaresinol, tricin, and diosmetin were isolated from O. vulgaris for the first time. A compound database of O. vulgaris was established based on the existing literature to predict the mechanism of O. vulgaris in the treatment of rheumatoid arthritis. The results suggest that the PI3K-Akt pathway mediates O. vulgaris and deserves more attention in the treatment of RA. Finally, the anti-rheumatoid arthritis effects of the four target compounds were validated with the decreased levels of NO, TNF-α, IL-6 and IL-1β in RAW 264.7 macrophage cells treated with LPS. The present study explored the potential targets and signaling pathways of O. vulgaris in the treatment of RA, which may help to illustrate the mechanisms involved in the action of O. vulgaris and may provide a better understanding of the relationship between O. vulgaris and RA. This study provides novel insights into the development of new drugs and utilization of Mongolian traditional Chinese medicine resources.

Reparative Effects of Ethanol-Induced Intestinal Barrier Injury by Flavonoid Luteolin via MAPK/NF-κB/MLCK and Nrf2 Signaling Pathways

Luteolin, a dietary flavonoid, has gained increasing interest as an intestinal protectant. This study aimed to evaluate the reparative effect of luteolin against ethanol-induced intestinal barrier damage in a Caco-2 cell monolayer model and the potential mechanisms. Luteolin attenuated ethanol-induced intestinal barrier injury, by increasing transepithelial monolayer resistance (TEER, 27.75 ± 14.75% of the ethanol group, p < 0.01), reducing Lucifer yellow flux (13.21 ± 1.23% of ethanol group, p < 0.01), and upregulating the expression of tight junction (TJ) proteins zonulin occludin-1 (ZO-1), occludin, and claudin-1 (37.963 ± 8.62%, 17.69 ± 7.35%, and 29.40 ± 8.08% of the ethanol group, respectively, p < 0.01). Further mechanistic studies showed that luteolin suppressed myosin light chain 2 (MLC) phosphorylation, myosin light chain kinase (MLCK) activation, nuclear factor kappa-B (NF-κB) nuclear translocation, and mitogen-activated-protein-kinase (MAPK) phosphorylation. Moreover, luteolin also acted as antioxidants indirectly by upregulating antioxidant-responsive-element (ARE) and nuclear factor (erythroid-derived 2)-like 2 (Nrf2) nuclear translocation to relieve ethanol-induced oxidative damage and TJ dysfunction. The results of the study indicate that luteolin may play an effective role in relieving intestinal barrier damage, and this effect is at least partially due to its indirect antioxidant capacity.

Systemic elucidation on the potential bioactive compounds and hypoglycemic mechanism of Polygonum multiflorum based on network pharmacology

BACKGROUND

Diabetes is a complex metabolic disease characterized by hyperglycemia, plaguing the whole world. However, the action mode of multi-component and multi-target for traditional Chinese medicine (TCM) could be a promising treatment of diabetes mellitus. According to the previous research, the TCM of Polygonum multiflorum (PM) showed noteworthy hypoglycemic effect. Up to now, its hypoglycemic active ingredients and mechanism of action are not yet clear. In this study, network pharmacology was employed to elucidate the potential bioactive compounds and hypoglycemic mechanism of PM.

METHODS

First, the compounds with good pharmacokinetic properties were screened from the self-established library of PM, and the targets of these compounds were predicted and collected through database. Relevant targets of diabetes were summarized by searching database. The intersection targets of compound-targets and disease-targets were obtained soon. Secondly, the interaction net between the compounds and the filtered targets was established. These key targets were enriched and analyzed by protein-protein interactions (PPI) analysis, molecular docking verification. Thirdly, the key genes were used to find the biologic pathway and explain the therapeutic mechanism by genome ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) analysis. Lastly, the part of potential bioactive compounds were under enzyme activity inhibition tests.

RESULTS

In this study, 29 hypoglycemic components and 63 hypoglycemic targets of PM were filtrated based on online network database. Then the component-target interaction network was constructed and five key components resveratrol, apigenin, kaempferol, quercetin and luteolin were further obtained. Sequential studies turned out, AKT1, EGFR, ESR1, PTGS2, MMP9, MAPK14, and KDR were the common key targets. Docking studies indicated that the bioactive compounds could stably bind the pockets of target proteins. There were 38 metabolic pathways, including regulation of lipolysis in adipocytes, prolactin signaling pathway, TNF signaling pathway, VEGF signaling pathway, FoxO signaling pathway, estrogen signaling pathway, linoleic acid metabolism, Rap1 signaling pathway, arachidonic acid metabolism, and osteoclast differentiation closely connected with the hypoglycemic mechanism of PM. And the enzyme activity inhibition tests showed the bioactive ingredients have great hypoglycemic activity.

CONCLUSION

In summary, the study used systems pharmacology to elucidate the main hypoglycemic components and mechanism of PM. The work provided a scientific basis for the further hypoglycemic effect research of PM and its monomer components, but also provided a reference for the secondary development of PM.

Simultaneous determination of nine constituents by validated UFLC-MS/MS in the plasma of cough variant asthma rats and its application to pharmacokinetic study after oral administration of Huanglong cough oral liquid

Huanglong cough oral liquid (HL), an important traditional Chinese medicine prescription for treating pediatric cough variant asthma (CVA) in Nanjing hospital of traditional Chinese medicine for many years. In this study, a selective, accurate and sensitive ultra fast liquid chromatography extreme resolution coupled with mass spectrometer (UFLC-MS/MS) method was established and validated for the simultaneous determination of nine constituents including morusin, ephedrine, praeruptorin A, praeruptorin B, luteolin, rosmarinic acid, quercetin, amygdalin, caffeic acid in CVA rat plasma sensitized and challenged with ovalbumin and cinnamaldehyde. Plasma samples were prepared by protein precipitation with four-fold amount of methanol. UFLC separation was performed on a Thermo Scientific AcclaimTM RSLC 120 C18 column (2.1 mm × 100 mm, 2.2 μm) with mobile phase containing methanol and 0.1% formic acid-water by gradient elution in 8.1 min at total flow of 0.3 mL/min. The determination of target compounds in plasma was operated by multiple reaction monitoring (MRM) mode with positive and negative electrospray ionization (ESI) source. The correlation coefficients (r) of all compounds were from 0.9930 to 0.9994 in the linear range. Lower limit of quantification (LLOQ, ng/mL) was 0.81, 2.01, 2.11, 1.17, 1.04, 0.89, 0.67, 1.45 and 0.59 for morusin, ephedrine, praeruptorin A, praeruptorin B, luteolin, rosmarinic acid, quercetin, amygdalin and caffeic acid, respectively. Intra- and inter-day accuracy and precision, extraction recovery, matrix effect, carryover effect, dilution integrity, and stability were within the limits specified. The established method was effectively applied to a pharmacokinetic study of the nine compounds in CVA rat plasma following oral administration HL exact (7.5, 15, 30 g/kg).

Pharmacokinetic Comparisons of Different Combinations of Yigan Jiangzhi Formula in Rats: Simultaneous Determination of Fourteen Components by UPLC-MS/MS

A rapid, specific, and sensitive analysis for simultaneous determination of fourteen components (daidzein, fermononetin, apigenin, luteolin, puerarin, ononin, calycosin-7-O-β-D-glucoside, tanshinol, rosmarinic acid, alkanoic acid, salvianolic acid B, berberine, jatrorrhizin, and palmatine) of Yigan Jiangzhi formula (YGJZF, a clinical experienced formula for damp-heat syndrome) in rat plasma was developed and validated using ultraperformance liquid chromatography coupled with mass spectrometry. Lower limit of quantitation ranged from 0.2-10.0 ng/mL, and the calibration curves showed good linearity over 500 times of measuring range. The validated method was successfully applied to the pharmacokinetics investigation of the fourteen compounds in rat plasma after oral administration of two different doses of YGJZF. Compared with the low-dose group of YGJZF, the high-dose group showed significant increase (P < 0.01 or P < 0.05) in maximum plasma concentration, maximum concentration time, and area under the plasma concentration-time curve and decrease (P < 0.01 or P < 0.05) in clearance of most of the fourteen analytes, which suggested that the bioavailability of these components could be enhanced by increasing dosage. The above results may provide useful information for cognizing the relationship between in vitro and in vivo data of the fourteen bioactive ingredients of YGJZF and further guiding rational clinical drug prescription.