Pharmacokinetics, tissue distribution and excretion study of Oroxylin A, Oroxylin A 7-O-glucuronide and Oroxylin A sodium sulfonate in rats after administration of Oroxylin A

Cellular and molecular mechanisms of oroxylin A in cancer therapy: Recent advances

Seeking an effective and safe scheme is the common goal of clinical treatment of tumor patients. In recent years, traditional Chinese medicine has attracted more and more attention in order to discover new drugs with good anti-tumor effects. Oroxylin A (OA) is a compound found in natural Oroxylum indicum and Scutellaria baicalensis Georgi plants and has been used in the treatment of various cancers. Studies have shown that OA has a wide range of powerful biological activities and plays an important role in neuroprotection, anti-inflammation, anti-virus, anti-allergy, anti-tumor and so on. OA shows high efficacy in tumor treatment. Therefore, it has attracted great attention of researchers all over the world. This review aims to discuss the anti-tumor effects of OA from the aspects of cell cycle arrest, induction of cell proliferation and apoptosis, induction of autophagy, anti-inflammation, inhibition of glycolysis, angiogenesis, invasion, metastasis and reversal of drug resistance. In addition, the safety and toxicity of the compound were also discussed. As a next step, to clarify the benefits and adverse effects of Oroxylin A in cancer patients further experiments, especially clinical trials, are needed.

In Vitro Assessment of Cortisol Release Inhibition, Bioaccessibility and Bioavailability of a Chemically Characterized Scutellaria lateriflora L. Hydroethanolic Extract

Excess cortisol release is associated with numerous health concerns, including psychiatric issues (i.e., anxiety, insomnia, and depression) and nonpsychiatric issues (i.e., osteoporosis). The aim of this study was to assess the in vitro inhibition of cortisol release, bioaccessibility, and bioavailability exerted by a chemically characterized Scutellaria lateriflora L. extract (SLE). The treatment of H295R cells with SLE at increasing, noncytotoxic, concentrations (5-30 ng/mL) showed significant inhibition of cortisol release ranging from 58 to 91%. The in vitro simulated gastric, duodenal, and gastroduodenal digestions, induced statistically significant reductions (p < 0.0001) in the bioactive polyphenolic compounds that most represented SLE. Bioavailability studies on duodenal digested SLE, using Caco-2 cells grown on transwell inserts and a parallel artificial membrane permeability assay, indicated oroxylin A glucuronide and oroxylin A were the only bioactive compounds able to cross the Caco-2 cell membrane and the artificial lipid membrane, respectively. The results suggest possible applications of SLE as a food supplement ingredient against cortisol-mediated stress response and the use of gastroresistant oral dosage forms to partially prevent the degradation of SLE bioactive compounds. In vivo studies and clinical trials remain necessary to draw a conclusion on the efficacy and tolerability of this plant extract.

Elucidation of Carboxylesterase Mediated Pharmacokinetic Interactions between Irinotecan and Oroxylin A in Rats via Physiologically Based Pharmacokinetic Modeling

PURPOSE

Our previous screening studies identified Oroxylin A (OXA) as a strong inhibitor on the carboxyolesterase mediated hydrolysis of irinotecan to SN-38. The current study employed a whole-body physiologically based pharmacokinetic (PBPK) modeling approach to investigate the underlying mechanisms of the carboxylesterase-mediated pharmacokinetics interactions between irinotecan and OXA in rats.

METHODS

Firstly, rats received irinotecan intravenous treatment at 35 μmol/kg without or with oral OXA pretreatment (2800 μmol/kg) daily for 5 days. On day 5, blood and tissues were collected for analyses of irinotecan/SN-38 concentrations and carboxylesterase expression. In addition, effects of OXA on the enzyme kinetics of irinotecan hydrolysis and unbound fractions of irinotecan and SN-38 in rat plasma, liver and intestine were also determined. Finally, a PBPK model that integrated the physiological parameters, enzyme kinetics, and physicochemical properties of irinotecan and OXA was developed.

RESULTS

Our PBPK model could accurately predict the pharmacokinetic profiles of irinotecan/SN-38, with AUC0-6h and Cmax values within ±27% of observed values. When OXA was included as a carboxylesterase inhibitor, the model could also predict the irinotecan/SN-38 plasma concentrations within twofold of those observed. In addition, the PBPK model indicated inhibition of carboxylesterase-mediated hydrolysis of irinotecan in the intestinal mucosa as the major underlying mechanism for the pharmacokinetics interactions between irinotecan and OXA.

CONCLUSION

A whole-body PBPK model was successfully developed to not only predict the impact of oral OXA pretreatment on the pharmacokinetics profiles of irinotecan but also reveal its inhibition on the intestinal carboxylesterase as the major underlying mechanism.

Scutellaria baicalensis Georgi and Their Natural Flavonoid Compounds in the Treatment of Ovarian Cancer: A Review

Ovarian cancer (OC) is one of the most common types of cancer in women with a high mortality rate, and the treatment of OC is prone to high recurrence rates and side effects. Scutellaria baicalensis (SB) is a herbal medicine with good anti-cancer activity, and several studies have shown that SB and its flavonoids have some anti-OC properties. This paper elucidated the common pathogenesis of OC, including cell proliferation and cell cycle regulation, cell invasion and metastasis, apoptosis and autophagy, drug resistance and angiogenesis. The mechanisms of SB and its flavonoids, wogonin, baicalein, baicalin, Oroxylin A, and scutellarein, in the treatment of OC, are revealed, such as wogonin inhibits proliferation, induces apoptosis, inhibits invasion and metastasis, and increases the cytotoxicity of the drug. Baicalein also inhibits vascular endothelial growth factor (VEGF) expression etc. Analyzing their advantages and disadvantages in treating OC provides a new perspective on the role of SB and its flavonoids in OC treatment. It serves as a resource for future OC research and development.

Anticancer potential of oroxylin A: from mechanistic insight to synergistic perspectives

Oroxylin A (OA), a well-known constituent of the root of Scutellariae plants, has been used in ethnomedicine already for centuries in treating various neoplastic disorders. However, only recent molecular studies have revealed the different mechanisms behind its action, demonstrating antiproliferative, anti-inflammatory, and proapoptotic effects, restricting also the spread of cancer cells to distant organs. A variety of cellular targets and modulated signal transduction pathways regulated by OA have been determined in diverse cells derived from different malignant tissues. In this review article, these anticancer activities are thoroughly described, representing OA as a potential lead structure for the design of novel more potent anticancer medicines. In addition, co-effects of this natural compound with conventional anticancer agents are analyzed and the advantages provided by nanotechnological methods for more efficient application of OA are discussed. In this way, OA might represent an excellent example of using ethnopharmacological knowledge for designing modern medicines.

Modulation of diverse oncogenic signaling pathways by oroxylin A: An important strategy for both cancer prevention and treatment

BACKGROUND

Regardless of major advances in diagnosis, prevention and treatment strategies, cancer is still a foreboding cause due to factors like chemoresistance, radioresistance, adverse side effects and cancer recurrence. Therefore, continuous development of unconventional approaches is a prerequisite to overcome foregoing glitches. Natural products have found their way into treatment of serious health conditions, including cancer since ancient times. The compound oroxylin A (OA) is one among those with enormous potential against different malignancies. It is a flavonoid obtained from the several plants such as Oroxylum indicum, Scutellaria baicalensis and S. lateriflora, Anchietea pyrifolia, and Aster himalaicus.

PURPOSE

The main purpose of this study is to comprehensively elucidate the anticancerous effects of OA against various malignancies and unravel their chemosensitization and radiosensitization potential. Pharmacokinetic and pharmacodynamic studies of OA have also been investigated.

METHOD

The literature on antineoplastic effects of OA was searched in PubMed and Scopus, including in vitro and in vivo studies and is summarized based on a systematic review protocol prepared according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The term "oroxylin A" was used in combination with "cancer" and all the title, abstracts and keywords appeared were considered.

RESULTS

In Scopus, a total of 157 articles appeared out of which 103 articles that did not meet the eligibility criteria were eliminated and 54 were critically evaluated. In PubMed, from the 85 results obtained, 26 articles were eliminated and 59 were included in the preparation of this review. Mounting number of studies have illustrated the anticancer effects of OA, and its mechanism of action.

CONCLUSION

OA is a promising natural flavonoid possessing wide range of pleiotropic properties and is a potential anticancer agent. It has a great potential in the treatment of multiple cancers including brain, breast, cervical, colon, esophageal, gall bladder, gastric, hematological, liver, lung, oral, ovarian, pancreatic and skin. However, lack of pharmacokinetic studies, toxicity assessments, and dose standardization studies and adverse effects limit the optimization of this compound as a therapeutic agent.

Oroxylin A: A Promising Flavonoid for Prevention and Treatment of Chronic Diseases

There have been magnificent advancements in the understanding of molecular mechanisms of chronic diseases over the past several years, but these diseases continue to be a considerable cause of death worldwide. Most of the approved medications available for the prevention and treatment of these diseases target only a single gene/protein/pathway and are known to cause severe side effects and are less effective than they are anticipated. Consequently, the development of finer therapeutics that outshine the existing ones is far-reaching. Natural compounds have enormous applications in curbing several disastrous and fatal diseases. Oroxylin A (OA) is a flavonoid obtained from the plants Oroxylum indicum, Scutellaria baicalensis, and S. lateriflora, which have distinctive pharmacological properties. OA modulates the important signaling pathways, including NF-κB, MAPK, ERK1/2, Wnt/β-catenin, PTEN/PI3K/Akt, and signaling molecules, such as TNF-α, TGF-ꞵ, MMPs, VEGF, interleukins, Bcl-2, caspases, HIF-1α, EMT proteins, Nrf-2, etc., which play a pivotal role in the molecular mechanism of chronic diseases. Overwhelming pieces of evidence expound on the anti-inflammatory, anti-bacterial, anti-viral, and anti-cancer potentials of this flavonoid, which makes it an engrossing compound for research. Numerous preclinical and clinical studies also displayed the promising potential of OA against cancer, cardiovascular diseases, inflammation, neurological disorders, rheumatoid arthritis, osteoarthritis, etc. Therefore, the current review focuses on delineating the role of OA in combating different chronic diseases and highlighting the intrinsic molecular mechanisms of its action.

Immunosuppressant flavonoids from Scutellaria baicalensis

Some plants used in Traditional Chinese Medicine serve as treatment for disease states where a suppression of the cellular immune response is desired. However, the compounds responsible for the immunosuppressant effects of these plants are not necessarily known. The immunosuppressant compounds in the roots of Scutellaria baicalensis, one of the most promising plants identified in a previous screening, were tracked by HPLC activity profiling and concomitant on-line spectroscopic analysis. Compounds were then isolated by preparative chromatography, and structures elucidated by spectroscopic methods. Twelve flavonoids (5-16) were identified from the active time windows, and structurally related flavones 2, 4, and 17, and flavanones 1 and 3 were isolated from adjacent fractions. All flavonoids possessed an unusual substitution pattern on the B-ring, with an absence of substituents at C-3 and C-4. Compounds 11, 13, 14, and 16 inhibited T-cell proliferation (IC₅₀ values at 12.1-39 μM) at non-cytotoxic concentrations. The findings may support the use of S. baicalensis in disorders where a modulation of the cellular immune response is desirable.

Oroxylin a Attenuates Limb Ischemia by Promoting Angiogenesis via Modulation of Endothelial Cell Migration

Oroxylin A (OA) has been shown to simultaneously increase coronary flow and provide a strong anti-inflammatory effect. In this study, we described the angiogenic properties of OA. OA treatment accelerated perfusion recovery, reduced tissue injury, and promoted angiogenesis after hindlimb ischemia (HLI). In addition, OA regulated the secretion of multiple cytokines, including vascular endothelial growth factor A (VEGFA), angiopoietin-2 (ANG-2), fibroblast growth factor-basic (FGF-2), and platelet derived growth factor BB (PDGF-BB). Specifically, those multiple cytokines were involved in cell migration, cell population proliferation, and angiogenesis. These effects were observed at 3, 7, and 14 days after HLI. In skeletal muscle cells, OA promoted the release of VEGFA and ANG-2. After OA treatment, the conditioned medium derived from skeletal muscle cells was found to significantly induce endothelial cell (EC) proliferation. OA also induced EC migration by activating the Ras homolog gene family member A (RhoA)/Rho-associated coiled-coil kinase 2 (ROCK-II) signaling pathway and the T-box20 (TBX20)/prokineticin 2 (PROK2) signaling pathway. In addition, OA was able to downregulate the number of macrophages and neutrophils, along with the secretion of interleukin-1β, at 3 days after HLI. These results expanded current knowledge about the beneficial effects of OA in angiogenesis and blood flow recovery. This research could open new directions for the development of novel therapeutic intervention for patients with peripheral artery disease (PAD).

In Vitro Glucuronidation of Caribbean Ciguatoxins in Fish: First Report of Conjugative Ciguatoxin Metabolites

Ciguatoxins (CTX) are potent marine neurotoxins, which can bioaccumulate in seafood, causing a severe and prevalent human illness known as ciguatera poisoning (CP). Despite the worldwide impact of ciguatera, effective disease management is hindered by a lack of knowledge regarding the movement and biotransformation of CTX congeners in marine food webs, particularly in the Caribbean and Western Atlantic. In this study we investigated the hepatic biotransformation of C-CTX across several fish and mammalian species through a series of in vitro metabolism assays focused on phase I (CYP P450; functionalization) and phase II (UGT; conjugation) reactions. Using liquid chromatography high-resolution mass spectrometry to explore potential C-CTX metabolites, we observed two glucuronide products of C-CTX-1/-2 and provided additional evidence from high-resolution tandem mass spectrometry to support their identification. Chemical reduction experiments confirmed that the metabolites were comprised of four distinct glucuronide products with the sugar attached at two separate sites on C-CTX-1/-2 and excluded the C-56 hydroxyl group as the conjugation site. Glucuronidation is a novel biotransformation pathway not yet reported for CTX or other related polyether phycotoxins, yet its occurrence across all fish species tested suggests that it could be a prevalent and important detoxification mechanism in marine organisms. The absence of glucuronidation observed in this study for both rat and human microsomes suggests that alternate biotransformation pathways may be dominant in higher vertebrates.

The Role and Therapeutic Targeting of JAK/STAT Signaling in Glioblastoma

Glioblastoma remains one of the deadliest and treatment-refractory human malignancies in large part due to its diffusely infiltrative nature, molecular heterogeneity, and capacity for immune escape. The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway contributes substantively to a wide variety of protumorigenic functions, including proliferation, anti-apoptosis, angiogenesis, stem cell maintenance, and immune suppression. We review the current state of knowledge regarding the biological role of JAK/STAT signaling in glioblastoma, therapeutic strategies, and future directions for the field.

An integrated strategy for profiling the chemical components of Scutellariae Radix and their exogenous substances in rats by ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry

RATIONALE

Traditional Chinese medicines (TCMs) attract worldwide attention because of their effects in clinical application recorded in China historical ancient codes and in records, such as 'Treatise on Febrile Diseases'. With the developments of drug analysis and research, evaluating the in vivo substances in TCMs has become of great importance. Scutellariae Radix (SR, named as huang-qing in China), the root of Scutellaria baicalensis Georgi, has shown favorable clinical effects and safety in the treatment of infection diseases; however, its in vivo compounds are unclear and need detailed investigation.

METHODS

An ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC/QTOF MS) method coupled to an integrated strategy involving diagnostic ions, neutral losses and a prediction platform was used to explore the constituents of SR, and their exogenous substances in rats.

RESULTS

A total of 118 chemical constituents mainly featuring five chemical structure types (flavone C-glycosides, flavone O-glycosides, free flavones, flavanones and phenylethanoid glycosides) were identified or tentatively characterized in SR, and 175 xenobiotics (68 prototypes and 107 metabolites) were profiled in rat plasma, urine, bile and feces after ingestion of SR. The metabolites were classified into four related chemical groups: flavone C-glycosides, flavone O-glycosides, flavanones and phenylethanoid glycosides. Phase II metabolism reactions, such as glucuronidation and sulfation, were the major metabolic reactions in addition to phase I reactions of hydrolysis and hydrogenation. The corresponding main metabolic features of SR in rats were also elucidated.

CONCLUSIONS

The metabolism of SR, as a whole, was systemically revealed for the first time, and our work also provided meaningful information for pharmacokinetics studies and pharmacological analysis of SR in future work.

Applications, phytochemistry, pharmacological effects, pharmacokinetics, toxicity of Scutellaria baicalensis Georgi. and its probably potential therapeutic effects on COVID-19: a review

Scutellaria baicalensis Georgi. (SB) is a common heat-clearing medicine in traditional Chinese medicine (TCM). It has been used for thousands of years in China and its neighboring countries. Clinically, it is mostly used to treat diseases such as cold and cough. SB has different harvesting periods and processed products for different clinical symptoms. Botanical researches proved that SB included in the Chinese Pharmacopoeia (1st, 2020) was consistent with the medicinal SB described in ancient books. Modern phytochemical analysis had found that SB contains hundreds of active ingredients, of which flavonoids are its major components. These chemical components are the material basis for SB to exert pharmacological effects. Pharmacological studies had shown that SB has a wide range of pharmacological activities such as antiinflammatory, antibacterial, antiviral, anticancer, liver protection, etc. The active ingredients of SB were mostly distributed in liver and kidney, and couldn't be absorbed into brain via oral absorption. SB's toxicity was mostly manifested in liver fibrosis and allergic reactions, mainly caused by baicalin. The non-medicinal application prospects of SB were broad, such as antibacterial plastics, UV-resistant silk, animal feed, etc. In response to the Coronavirus Disease In 2019 (COVID-19), based on the network pharmacology research, SB's active ingredients may have potential therapeutic effects, such as baicalin and baicalein. Therefore, the exact therapeutic effects are still need to be determined in clinical trials. SB has been reviewed in the past 2 years, but the content of these articles were not comprehensive and accurate. In view of the above, we made a comprehensive overview of the research progress of SB, and expect to provide ideas for the follow-up study of SB.