Radioprotective effects of dragon's blood and its extracts on radiation-induced myelosuppressive mice

Potential of CME@ZIF-8 MOF Nanoformulation: Smart Delivery of Silymarin for Enhanced Performance and Mechanism in Albino Rats

Silymarin, an antioxidant, is locally used for kidney and heart ailments. However, its limited water solubility and less oral bioavailability limit its therapeutic efficiency. The present study investigated the enhancement of solubility and bioavailability of silymarin by loading it in Cordia myxa plant extract-coated zeolitic imidazole framework (CME@ZIF-8) against carbon tetrachloride (CCl4)-induced nephrotoxicity and cardiac toxicity in albino rats. The synthesized PEG-coated silymarin drug-loaded CME@ZIF-8 MOFs (PEG-Sily@CME@ZIF-8) were characterized by scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, energy dispersive X-ray spectroscopy, UV-visible spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, and zeta potential. The average crystal size of CME@ZIF-8 and PEG-Sily@CME@ZIF-8 was 12.69 and 16.81 nm, respectively. The silymarin drug loading percentage in PEG-Sily@CME@ZIF-8 was 33.05% (w/w). In the animal model with CCl4 treatment, different parameters like serum profile, enzymatic level, genotoxicity, and histopathology were assessed. Treatment with PEG-Sily@CME@ZIF-8 with different doses of 500, 1000, and 1500 μg/kg body weight efficiently ameliorated the alterations in the antioxidant defenses, biochemical parameters, and histopathological alterations and DNA damage in comparison to silymarin drug in a CCl4-induced toxicity rat model via alleviating the cellular abnormalities and attenuation of normal antioxidant enzymes levels. Moreover, the molecular mechanism of drug-silymarin interaction with the target protein was investigated. It involves the binding pockets of silymarin molecules with VEGFR, TNF-α, NLRP3, AT1R, NOX1, RIPK1, Caspase-3, CHOP, and MMP-9 proteins, elucidating the silymarin-protein interactions by the formation of hydrogen bonds and hydrophobic interactions. This study suggests that the nanodrug PEG-Sily@CME@ZIF-8 MOFs protect the kidneys and heart possibly by mitigating oxidative stress more efficiently than the conventional drug silymarin.

Comprehensive evaluation of Dragon's Blood in combination with borneol in ameliorating ischemic/reperfusion brain injury using RNA sequencing, metabolomics, and 16S rRNA sequencing

Ischemia/reperfusion (IR) can induce deleterious responses such as apoptosis, inflammation, and oxidative stress; however, there are currently no efficient therapeutics to treat IR brain injury. Dragon's blood (DB) plays a significant role in treating ischemic stroke in China. Borneol (B) is an upper ushering drug that guides drugs to the target organs, including the brain. Therefore, we hypothesized that the combination of DB and B (DB + B) would provide cooperative therapeutic benefits for IR brain injury. To confirm this, we first investigated the protective effect of DB + B in an IR brain injury rat model using the modified neurological severity score (mNSS), infarction size measure, HE staining, and laser speckle contrast imaging. Then, we comprehensively evaluated the mechanism of DB + B in ameliorating IR brain injury based on RNA sequencing, serum untargeted metabolomics, and 16S rRNA sequencing. We have confirmed that DB + B enhanced the efficacy of the ischemic stroke treatment compared to DB or B alone for the first time. Our study provisionally confirms that the mechanism by which DB + B prevents IR brain injury is related to the maintenance of intestinal microecological balance and regulation of metabolic dysfunction, thereby suppressing inflammation and regulating immunity. DB + B may effectively regulate intestinal flora including o_Pseudomonadales, s_Bacteroides_caecimuris, o_unidentified_Bacilli, f-Pseudomonadaceae, and g-Pseudomonas, mainly regulate serum metabolites including improve the protective benefit of IR brain injury lysoPCs and lysoPEs, thus inhibiting TLR4/MyD88/NF-κB and IL-17 signing pathway to reduce inflammatory reactions. hat this mechanism is associated with the maintenance of intestinal flora balance and the regulation of metabolic dysfunction, thereby suppressing inflammation and regulating immunity. This provides scientific support for the clinical translation of DB + B in the prevention and treatment of ischemic stroke and establishes a basis for further investigation of its therapeutic mechanism.

Mechanism of herb pair containing Astragali Radix and Spatholobi Caulis in the treatment of myelosuppression based on network pharmacology and experimental investigation

ETHNOPHARMACOLOGICAL RELEVANCE

The Astragali Radix and Spatholobi Caulis herb pair (ARSC) is one of the most commonly used herbal combinations for bone marrow suppression. According to traditional Chinese medicine, Astragali Radix strengthens the spleen and replenishes qi, while Spatholobi Caulis is a hematinic agent that promotes blood circulation and enrichment. The compatibility of the two helps the body to tonify the spleen and kidneys and compensate for visceral deficiencies. However, the multi-target mechanism of ARSC in bone marrow suppression has remained largely unknown.

AIM OF THE STUDY

The aim of this study is to explore the key targets and signaling pathways of the traditional Chinese herbal pair ARSC for the treatment of bone marrow suppression.

MATERIALS AND METHODS

The active components of ARSC and targets for myelosuppression were screened using network databases. Cytoscape 3.8.0 was used to construct compound-target, compound-disease-target and protein-protein interaction (PPI) networks. Go-function and pathway enrichment analyses were performed to explore the potential mechanism. In vivo animal experiments were conducted to verify the molecular mechanisms.

RESULTS

The 36 active compounds were identified from the ARSC, and a total of 108 genes involved in myelosuppression were screened. VEGFA, IL6, TNF, JUN, STAT3, PTGS2, CASP3 and MMP9 genes were identified as potential drug targets in the PPI network analyzed by CytoHubba. Enrichment analysis indicated that ARSC may treat myelosuppression through various biological processes, such as apoptosis, TNF-α signaling pathway via NF-κB, PI3K/AKT/mTOR signaling pathway, IL6/JAK/STAT3 signaling pathway, P53 signaling pathway and G2/M checkpoint signaling pathway. The results of the experiment showed that the aqueous extract of ARSC significantly alleviated myelosuppression, reduced the apoptosis rate of bone marrow cells, upregulated the mRNA expression levels of TNF-α, IL-6 and VEGF, and promoted NF-κB phosphorylation in myelosuppressed mice.

CONCLUSIONS

This study identified the active components and relevant mechanisms of ARSC in the treatment of myelosuppression. Our findings predicted that ARSC could treat bone marrow suppression through multiple components, multiple targets and multiple pathways. Pharmacological experiments showed that ARSC alleviated fluorouracil-induced myelosuppression by reducing the apoptosis rate of bone marrow cells and regulating the TNF-α/NF-κB signaling pathway.

Casting Zinc Oxide Nanoparticles Using Fagonia Blend Microbial Arrest

Physical and chemical methods for production of nanoparticles (NPs) are not only harmful for environment but also toxic for living organism. The present study attempts to synthesize ZnO NPs using the natural plant extract of Fagonia cretica. The phytochemical screening of F. cretica water extract was performed to check the presence of biologically active compounds like alkaloids, tannins, carbohydrates, proteins, phenols, saponins, flavonoids, and steroids. Well-prepared ZnO NPs given sharp absorption peak at 362 were confirmed by UV-visible. XRD analysis showed the ZnO NPs having wurtzite hexagonal structure with crystalline form. TEM analysis endorses flower-shaped ZnO nanoparticles ~ 100-1000 nm. FTIR spectrum suggested the involvement of phenolic groups and amino acids and amide linkages in protein performs as the stabilizing agent in the synthesis of ZnO NPs. The ZnO NPs showed strong antibacterial behavior against two bacterial strains Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli. In addition, ZnO NPs exhibited strong antioxidant activity of 79%:85.6%:89.9% at 5 μg/mL:10 μg/mL:5 μg/mL concentration of ZnO NPs respectively. This work indicates that Fagonia is considered to be appropriate and promising candidate for extending the innovative applications in the field of medicine and industry and also helpful and useful to the scientific communities.

The PI3K/AKT Pathway-The Potential Key Mechanisms of Traditional Chinese Medicine for Stroke

Stroke is associated with a high disability and fatality rate, and adversely affects the quality of life of patients and their families. Traditional Chinese Medicine (TCM) has been used effectively in the treatment of stroke for more than 2000 years in China and surrounding countries and regions, and over the years, this field has gleaned extensive clinical treatment experience. The Phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT) pathway is important for regulation of cell migration, proliferation, differentiation, and apoptosis, and plays a vital role in vascularization and oxidative stress in stroke. Current Western medicine treatment protocols for stroke include mainly pharmacologic or mechanical thrombectomy to restore blood flow. This review collates recent advances in the past 5 years in the TCM treatment of stroke involving the PI3K/AKT pathway. TCM treatment significantly reduces neuronal damage, inhibits cell apoptosis, and delays progression of stroke via various PI3K/AKT-mediated downstream pathways. In the future, TCM can provide new perspectives and directions for exploring the key factors, and effective activators or inhibitors that affect occurrence and progression of stroke, thereby facilitating treatment.

Cordyceps sinensis aqueous extract regulates the adaptive immunity of mice subjected to 60 Co γ irradiation

Cordyceps sinensis (CS) is a traditional Chinese medicine that is known for treating various diseases, and particularly for exerting therapeutic effects in immune disorders. The adaptive immunoregulatory effects of CS aqueous extract (CSAE) on γ-irradiated mice have not been reported previously. The study aimed to evaluate the therapeutic effects of CSAE in mice immunosuppressed by irradiation. We observed that CSAE administration significantly increased body weight and spleen index, as well as the number of white blood cells, lymphocytes, and platelets in peripheral blood, T and B lymphocytes in spleen tissue, and total serum immunoglobulins in irradiated mice, whereas total serum pro-inflammatory cytokine levels were decreased. Collectively, CSAE maintained the structural integrity of spleen tissue and repaired its damage in irradiated mice as shown by hematoxylin and eosin staining, and decreased the number of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positive splenocytes. Mechanistically, CSAE upregulated Bcl-2, and downregulated Bax and cleaved caspase-3 in spleen of irradiated mice. However, there were no significant differences in red blood cells and neutrophils in different groups. The results revealed that CSAE had protective effects against irradiation-induced immunosuppression, which was likely associated with an antiapoptotic effect and the regulation of adaptive immunity.

From Vietnamese plants to a biflavonoid that relieves inflammation by triggering the lipid mediator class switch to resolution

Chronic inflammation results from excessive pro-inflammatory signaling and the failure to resolve the inflammatory reaction. Lipid mediators orchestrate both the initiation and resolution of inflammation. Switching from pro-inflammatory to pro-resolving lipid mediator biosynthesis is considered as efficient strategy to relieve chronic inflammation, though drug candidates exhibiting such features are unknown. Starting from a library of Vietnamese medical plant extracts, we identified isomers of the biflavanoid 8-methylsocotrin-4'-ol from Dracaena cambodiana, which limit inflammation by targeting 5-lipoxygenase and switching the lipid mediator profile from leukotrienes to specialized pro-resolving mediators (SPM). Elucidation of the absolute configurations of 8-methylsocotrin-4'-ol revealed the 2S,γS-isomer being most active, and molecular docking studies suggest that the compound binds to an allosteric site between the 5-lipoxygenase subdomains. We identified additional subordinate targets within lipid mediator biosynthesis, including microsomal prostaglandin E2 synthase-1. Leukotriene production is efficiently suppressed in activated human neutrophils, macrophages, and blood, while the induction of SPM biosynthesis is restricted to M2 macrophages. The shift from leukotrienes to SPM was also evident in mouse peritonitis in vivo and accompanied by a substantial decrease in immune cell infiltration. In summary, we disclose a promising drug candidate that combines potent 5-lipoxygenase inhibition with the favorable reprogramming of lipid mediator profiles.

Dragon's Blood Regulates Rac1-WAVE2-Arp2/3 Signaling Pathway to Protect Rat Intestinal Epithelial Barrier Dysfunction Induced by Simulated Microgravity

Dragon’s Blood is a red resin from Dracaena cochinchinensis (Lour.) S.C. Chen (Yunnan, China). As a traditional Chinese medicinal herb, it has shown protective effects on intestinal disorders. Microgravity could alter intestinal homeostasis. However, the potential herbal drugs for preventing intestine epithelial barrier (IEB) dysfunction under microgravity are not available. This study aimed to investigate the effects of Dragon’s Blood (DB) on microgravity-induced IEB injury and explore its underlying mechanism. A rat tail-suspension model was used to simulate microgravity (SMG). Histomorphology, ultrastructure, permeability, and expression of junction proteins in jejunum, ileum, and colon of SMG rats were determined. Proteomic analysis was used to identify differentially expressed proteins (DEPs) in rat ileum mucosa altered by DB. The potential mechanism of DB to protect IEB dysfunction was validated by western blotting. The effects of several components in DB were evaluated in SMG-treated Caco-2 cells. DB protected against IEB disruption by repairing microvilli and crypts, inhibiting inflammatory factors, lowering the permeability and upregulating the expression of tight and adherens junction proteins in the ileum of SMG rats. Proteomic analysis showed that DB regulated 1080 DEPs in rat ileum mucosa. DEPs were significantly annotated in cell–cell adhesion, focal adhesion, and cytoskeleton regulation. DB increased the expression of Rac1-WAVE2-Arp2/3 pathway proteins and F-actin to G-actin ratio, which promoted the formation of focal adhesions. Loureirin C in DB showed a protective effect on epithelial barrier injury in SMG-treated Caco-2 cells. DB could protect against IEB dysfunction induced by SMG, and its mechanism is associated with the formation of focal adhesions mediated by the Rac1-WAVE2-Arp2/3 pathway, which benefits intestinal epithelial cell migration and barrier repair.

Fractionation of Biomolecules in Withania coagulans Extract for Bioreductive Nanoparticle Synthesis, Antifungal and Biofilm Activity

Withania coagulans contains a complex mixture of various bioactive compounds. In order to reduce the complexity of the plant extract to purify its phytochemical biomolecules, a novel fractionation strategy using different solvent combination ratios was applied to isolate twelve bioactive fractions. These fractions were tested for activity in the biogenic synthesis of cobalt oxide nanoparticles, biofilm and antifungal activities. The results revealed that plant extract with bioactive fractions in 30% ratio for all solvent combinations showed more potent bioreducing power, according to the observed color changes and the appearance of representative absorption peaks at 500-510 nm in the UV-visible spectra which confirm the synthesis of cobalt oxide nanoparticles (Co3O4 NPs). XRD diffraction was used to define the crystal structure, size and phase composition of the products. The fractions obtained using 90% methanol/hexane and 30% methanol/hexane showed more effectiveness against biofilm formation by Pseudomonas aeruginosa and Staphylococcus aureus so these fractions could potentially be used to treat bacterial infections. The 90% hexane/H2O fraction showed excellent antifungal activity against Aspergillus niger and Candida albicans, while the 70% methanol/hexane fraction showed good antifungal activity for C. albicans, so these fractions are potentially useful for the treatment of various fungal infections. On the whole it was concluded that fractionation based on effective combinations of methanol/hexane was useful to investigate and study bioactive compounds, and the active compounds from these fractions may be further purified and tested in various clinical trials.

Systems Pharmacology-Dissection of the Molecular Mechanisms of Dragon's Blood in Improving Ischemic Stroke Prognosis

Materials and Methods

(1) Based on system-pharmacology platform, the potential active compounds of DB are screened out according to ADME. (2) The ischemic stroke-related targets are predicted by utilizing these active compounds as probes, mapping the targets to the CTD database to establish a molecular-target-disease network. (3) To analyze the mechanism of DB treatment for the prognosis of ischemic stroke, we used the Metascape and DAVID databases to construct "ischemic stroke pathways". (4) PC12 cells were used to explore the protective effect of loureirin B on oxygen-glucose deprivation/reperfusion (OGD/R) injury, and BV-2 cells were used to determine the anti-inflammation effect of 4',7-dihydroxyflavone.

Results

Finally, we obtained 38 active compounds and 58 stroke-related targets. Network and pathway analysis indicate that DB is effective in the treatment of ischemic stroke by enhancing cell survival and inhibiting inflammatory and antiplatelet activation. In in vitro experiments, the main component loureirin B promoted the expression of HO-1 and Bcl-2 via positive regulation of PI3K/AKT/CREB and Nrf2 signaling pathways in PC12 cells against OGD/R damage. And the anti-inflammatory activity of 4',7-dihydroxyflavone was related to the inhibition of COX-2, TNF-α, and IL-6 in LPS-induced BV-2 cells.

Conclusions

In our study, the results illustrated that DB in improving ischemic stroke prognosis may involve enhancing cell survival and antioxidant, anti-inflammation, and antiplatelet activities.

Celastrol Alleviates Gamma Irradiation-Induced Damage by Modulating Diverse Inflammatory Mediators

The present study aimed to explore the possible radioprotective effects of celastrol and relevant molecular mechanisms in an in vitro cell and in vivo mouse models exposed to gamma radiation. Human keratinocytes (HaCaT) and foreskin fibroblast (BJ) cells were exposed to gamma radiation of 20 Gy, followed by treatment with celastrol for 24 h. Cell viability, reactive oxygen species (ROS), nitric oxide (NO) and glutathione (GSH) production, lipid peroxidation, DNA damage, inflammatory cytokine levels, and NF-κB pathway activation were examined. The survival rate, levels of interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) in blood, and p65 and phospho-p65 expression were also evaluated in mice after exposure to gamma radiation and celastrol treatment. The gamma irradiation of HaCaT cells induced decreased cell viability, but treatment with celastrol significantly blocked this cytotoxicity. Gamma irradiation also increased free radical production (e.g., ROS and NO), decreased the level of GSH, and enhanced oxidative DNA damage and lipid peroxidation in cells, which were effectively reversed by celastrol treatment. Moreover, inflammatory responses induced by gamma irradiation, as demonstrated by increased levels of IL-6, TNF-α, and IL-1β, were also blocked by celastrol. The increased activity of NF-κB DNA binding following gamma radiation was significantly attenuated after celastrol treatment. In the irradiated mice, treatment with celastrol significantly improved overall survival rate, reduced the excessive inflammatory responses, and decreased NF-κB activity. As a NF-κB pathway blocker and antioxidant, celastrol may represent a promising pharmacological agent with protective effects against gamma irradiation-induced injury.

Phenolic constituents, pharmacological activities, quality control, and metabolism of Dracaena species: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Dragon's blood (Chinese name: Xuejie), which comprises red resins obtained from several plants (27 species from 4 families), is drawing worldwide interests in medicinal applications owing to its broad pharmacological spectrum such as promoting blood circulation, regenerating muscle, relieving swelling and pain, maintaining hemostasis, etc. AIM OF THE STUDY: This work aims to evaluate current research progress on phenolic constituents, pharmacological activities, quality control, and metabolism of six Dracaena plants, namely, Dracaena cochinchinensis (Lour.) S.C.Chen, D. cambodiana Pierre ex Gagnep., D. cinnabari Balf. f., D. draco (L.) L., D. loureiroi Gagnep., and D. schizantha Baker, figure out the shortcomings of existing studies, and provide meaningful guidelines for future investigations.

METHODS

Extensive database retrieval, such as SciFinder, PubMed, CNKI, ChemSpider, etc., was performed by using the keywords "Dracaena," "dragon's blood," as well as the Latin names of the six Dracaena species. In addition, relevant textbooks, patents, reviews, and documents were also employed to ensure sufficient information is collected.

RESULTS

Flavonoids and their oligomers are the primary chemical clusters distributed in Dracaena plants. Pharmacological activities including analgesic, anti-inflammatory, antibacterial, hypolipidemic, hypoglycemic, and cytotoxic effects; bi-directional regulation effects on hemorheology; and cardiovascular and cerebrovascular effects have been disclosed by modern pharmacological evaluations. The chemical and metabolic profiles after oral administration of dragon's blood extract were preliminarily characterized. However, some of the pharmacological investigations reported only elementary methodologies and unreliable findings, and even worse, some important aspects were questionable or missing in these articles.

CONCLUSIONS

Dragon's blood is a valuable source of bioactive compounds, mainly flavonoids and their oligomers. Its potential therapeutic effects on different diseases are attractive, such as the notable effect on cardiovascular diseases. In future studies, there is an urgent need to test the effect of this extract on appropriate cell lines and animal models to analyze its ethnopharmacological applications; moreover, "composition-effect correlation" methods and omics technologies are demanded for identifying the effective material basis and therapeutic mechanisms before entering into clinical trials. Moreover, attention should be paid to the chemical profiling and quality evaluation of this precious herbal medicine.

Pterostilbene, an active component of the dragon's blood extract, acts as an antidepressant in adult rats

BACKGROUND

Hippocampal neurogenesis has been widely considered as one of the potential biological mechanisms for the treatment of depression caused by chronic stress. Many natural products have been reported to be beneficial for neurogenesis.

OBJECTIVES

The present study is designed to investigate the effect of dragon's blood extract (DBE) and its biologically active compound, pterostilbene (PTE), on hippocampal neurogenesis.

METHODS

The male Sprague-Dawley (SD) rats were used in this study, which were maintained on the normal, DBE and PTE diet groups for 4 weeks before dissection in the normal rat model and behavioral testing in the CUS depression rat model. Meanwhile, DMI-treated rats are subcutaneously injected with DMI (10 mg/kg, i.p.).

RESULTS

Results revealed that DBE and PTE have the ability to promote hippocampal neurogenesis. DBE and PTE also promoted the proliferation of neural stem cells isolated from the brain of suckling rats. Oral administration of DBE and PTE induced the proliferation, migration, and differentiation of neural progenitor cells (NPCs) in chronic unexpected stressed (CUS) model rats, and improved the behavioral ability and alleviated depress-like symptoms of CUS rats. It was also observed that PTE treatment significantly induced the expression of neurogenesis-related factors, including BDNF, pERK, and pCREB.

CONCLUSION

Oral administration of PTE could affect neurogenesis and it is likely to be achieved via BDNF/ERK/CREB-associated signaling pathways.

Simulated Microgravity Altered the Metabolism of Loureirin B and the Expression of Major Cytochrome P450 in Liver of Rats

Loureirin B (LB) is the marker compound of dragon blood (DB), which exhibits great potentials in protecting astronauts' health against radiation and simulated microgravity (SM). Pharmacokinetics of LB is reported to be significantly altered by SM. Here, we investigated key metabolic features of LB in rat liver microsome (RLM) and the effects of SM on LB metabolism as well as on expression of major hepatic cytochrome P450 (CYP450) isoforms. Ten metabolites were tentatively identified based on fragmentation pathways using LC-MS/MS method and elimination kinetics of LB followed a typical Michaelis-Menten equation (V max was 1.32 μg/min/mg and K m was 13.33 μg/mL). CYP1A2, CYP2C11, CYP2D1, and CYP3A2 were involved in the metabolism of LB and the relative strength was: CYP3A2 > CYP2C11 > CYP2D1 > CYP1A2. Comparative studies suggested that elimination of LB in RLM was remarkably increased by 3-day and 14-day SM, and the generation of identified metabolites was affected as well. Additionally, 3-day and 14-day SM showed obvious regulatory effects on the expression of major CYP450 isoforms, which might contribute to the increased elimination of LB. The data provided supports for the application of DB as a protective agent and the reasonable use of current medications metabolized by hepatic CYP450 in space missions.

Metabolic profiling of five flavonoids from Dragon's Blood in human liver microsomes using high-performance liquid chromatography coupled with high resolution mass spectrometry

Although much is known about the pharmacological activities of Dragon's Blood (DB, a traditional Chinese herb), its metabolism in human liver microsomes (HLMs) and the cytochrome P450 (CYP) enzymes has not been studied. This study aims to identify the metabolic profile of five flavonoids (loureirin A, loureirin B, loureirin C, 7,4'-dihydroxyflavone and 5,7,4'-trihydroxyflavanone) from DB in HLMs as well as the CYP enzymes that are involved in the metabolism of them. High-resolution mass spectrometry was used to characterize the structures of their metabolites and 10 cDNA-expressed CYP enzymes (CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4 and CYP3A5) were used to verify which isozymes mediate in the metabolism of the metabolites. Totally, 29 metabolites including 10 metabolites of loureirin A, 10 metabolites of loureirin B, 4 metabolites of loureirin C, 2 metabolites of 7,4'-dihydroxyflavone and 3 metabolites of 5,7,4'-trihydroxyflavanone were elucidated and identified on the basis of the high-resolution MSⁿ data. The metabolic profile of the five flavonoids in HLMs involved hydroxylation, oxidation and demethylation. Among them, hydroxylation was the predominant biotransformation of the five flavonoids in HLMs, occurring in combination with other metabolic reactions. Assay with recombinant P450s revealed that CYP2C9 and CYP2C19 played an important role in the hydroxylation of flavonoids in HLMs. To the best of our knowledge, this is the first in vitro evaluation of the metabolic profile of loureirin A, loureirin B, loureirin C, 7,4'-dihydroxyflavone and 5,7,4'-trihydroxyflavanone in HLMs.