Lindera obtusiloba Blume Alleviates Non-Alcoholic Fatty Liver Disease Promoted by Nε-(carboxymethyl)lysine.

Non-alcoholic fatty liver disease (NAFLD) is a major issue because it is closely associated with metabolic diseases. Advanced glycation end products (AGEs) are implicated as risk factors for steatosis during NAFLD progression. AGEs influence NAFLD progression through a receptor-independent pathway involving AGE cross-link formation and a receptor-dependent pathway that binds to receptors like receptors for advanced glycation end products (RAGE). The objectives of this study are to examine the effect of Lindera obtusiloba Blume (LO) on NAFLD promoted by Nε-(carboxymethyl)lysine (CML), one of the most common dietary AGEs. The anti-glycation effects of LO were evaluated by inhibiting the AGEs formation and AGEs-collagen cross-links breaking. The efficacy of LO against NAFLD promoted by CML was assessed using both in vitro and in vivo models. NAFLD was induced in mice by feeding a high-fat diet and orally administering CML over a period of 12 weeks, and the effects of LO on lipid metabolism and its regulatory mechanisms were investigated. LO showed the effect of inhibited AGEs formation and breakage, and collagen cross-linking. Fed a high-fat diet with administered CML by gavage, LO administration resulted in a reduction in body weight, fat mass, serum triglycerides, total cholesterol, and low-density lipoprotein cholesterol levels. LO reduced hepatic CML accumulation and RAGE expression in mice fed a high-fat diet and orally administered CML. LO alleviated hepatic steatosis accompanied by lipid accumulation and histological damage by suppressing the expression of sterol regulatory element-binding protein 1c, carbohydrate response element binding protein, fatty acid synthase, stearoyl-CoA desaturase1, tumor necrosis factor-α, and interleukin-1ß. LO alleviated the MAPK/NF-κB expression by attenuating CML and RAGE expression. Taken together, our results demonstrate that LO alleviates the progression of NAFLD by lowering the levels of AGEs by downregulating CML/RAGE expression.

Linderae Radix extract attenuates ulcerative colitis by inhibiting the JAK/STAT signaling pathway.

BACKGROUND: Linderae Radix (LR), the dried root of Lindera aggregata (Sims) Kosterm., is a traditional Chinese herbal medicine that has been used for thousands of years for promoting Qi circulation, soothing the liver, and treating diarrhea and dysentery. Previous studies have found that ethanol extract of LR plays an anti-ulcerative colitis (UC) role by regulating Th17/ Treg balance. Water extract is the classic clinical application form of LR, but the effect of water extract of LR (LRWE) on UC and its underlying mechanism is still unclear. PURPOSE: Purpose: UC is a gastrointestinal disease characterized by intestinal inflammation, mucosal injury, and fibrosis, and it is one of the high-risk factors for colon cancer. However, there is still a lack of remedies with satisfactory effects. This study aimed to investigate the efficacy and the potential mechanism of LRWE against UC. METHODS: LRWE samples were prepared using a reflux extraction method. Colitis in mice was induced by administering 2.5 % DSS water solution to evaluate the therapeutic effect of LRWE by assessing disease activity score, colon length, and fecal morphology. H&E staining, TEM, Masson staining, and AB-PAS staining were applied to observe histopathological changes in the colon tissues. Differentially expressed genes in colon tissues were analyzed by transcriptomics. Cell apoptosis was detected by TUNEL staining. The expression of inflammatory factors such as IL-6 and IL-1ß, as well as the expression of p-STAT1, p-JAK2, p-STAT3, Bax, and Bcl-2, were detected by immunofluorescence and immunohistochemistry. The expression of occludin, Bcl-2, Bax, and JAK/STAT signaling pathway-related vital proteins were quantified by Western blot (WB). RESULTS: LRWE alleviated body weight loss, colon shortening, DAI scores, pathological changes, and ultrastructural features of colon tissue in mice with colitis. It also inhibited the increase of pro-inflammatory cytokines (such as TNF-α, IL-6, and IL-1ß) and increased IL-10 levels. Additionally, it protected the intestinal barrier by upregulating the expression of Occludin and Mucin-2. Mechanistically, LRWE could inhibit the activation of JAK-STAT signaling pathway by reducing the protein expression of p-JAK2, p-STAT3, p-STAT1, Bcl2, and Bax, thus reducing the inflammatory responses and inhibiting cell apoptosis. CONCLUSION: LRWE has a protective effect on DSS-induced UC. This effect is related to the inhibition of the JAK-STAT signaling pathway, the improvement of intestinal inflammation, and the reduction of intestinal epithelial cell apoptosis.

Norboldine improves cognitive impairment and pathological features in Alzheimer's disease by activating AMPK/GSK3ß/Nrf2 signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Lindera aggregata (Sims) Kosterm is a common traditional herb that has multiple bioactivities. Radix Linderae (LR), the dry roots of Lindera aggregata (Sims) Kosterm, is a traditional Chinese herbal medicine with antioxidant, anti-inflammatory and immunomodulatory properties, first found in Kaibao Era. Norboldine (Nor) is an alkaloid extracted from LR and is one of the primary active ingredients of LR. However, the pharmacological functions and mechanism of Nor in Alzheimer's disease (AD) are still unknown. AIM OF THE STUDY: This study aims to investigate the effect and mechanism of Nor therapy in improving the cognitive impairment and pathological features of 3 × Tg mice. MATERIALS AND METHODS: 3 × Tg mice were treated with two concentrations of Nor for one month and then the memory and cognitive abilities of mice were assessed by novel object recognition experiment and Morris water maze. The impact of Nor on the pathology of ADwere examined in PC12 cells and animal tissues using western blotting and immunofluorescence. Finally, western blotting was used to verify the anti-apoptotic effect of Nor by activating AMPK/GSK3ß/Nrf2 signaling pathway at animal and cellular levels. RESULTS: In this study, we showed that Nor treatment improved the capacity of the learning and memory of 3 × Tg mice and alleviated AD pathology such as Aß deposition. In addition, Nor restored the abnormalities of mitochondrial membrane potential, significantly reduced the production of intracellular ROS and neuronal cell apoptosis. Mechanistically, we combined network pharmacology and experimental verification to show that Nor may exert antioxidant stress and anti-apoptotic through the AMPK/GSK3ß/Nrf2 signaling pathway. CONCLUSION: Our data provide some evidence that Nor exerts a neuroprotective effect through the AMPK/GSK3ß/Nrf2 pathway, thereby improving cognitive impairment in AD model mice. Natural products derived from traditional Chinese medicines are becoming increasingly popular in the process of new drug development and discovery, and our findings provide new perspectives for the discovery of improved treatment strategies for AD.

Norisoboldine, a Natural Alkaloid from Lindera aggregata (Sims) Kosterm, Promotes Osteogenic Differentiation via S6K1 Signaling Pathway and Prevents Bone Loss in OVX Mice.

SCOPE: Norisoboldine (NOR) is a major isoquinoline alkaloid component in the traditional Chinese herbal plant Lindera aggregata (Sims) Kosterm, with previously reported anti-osteoclast differentiation and antiarthritis properties. However, the roles of NOR on osteoblasts, bone marrow mesenchymal stem cells (BMSCs), and osteoporosis in vivo have never been well established. METHODS AND RESULTS: This study investigates the ability of NOR to improve bone formation in vitro and in vivo. Osteoblasts and BMSCs are used to study the effect of NOR on osteogenic and adipogenic differentiation. It finds that NOR promotes osteogenic differentiation of osteoblasts and BMSCs, while inhibiting adipogenic differentiation of BMSCs by reducing the relative expression of peroxisome proliferator-activated receptor Î³ (Ppar-γ) and adiponectin, C1Q and collagen domain containing (Adipoq). Mechanistic studies show that NOR increases osteoblast differentiation through the mechanistic target of rapamycin kinase (mTOR)/ribosomal protein S6 kinase; polypeptide 1 (S6K1) pathway, and treatment with an mTOR inhibitor rapamycin blocked the NOR-induced increase in mineral accumulation. Finally, the study evaluates the therapeutic potential of NOR in a mouse model of ovariectomy (OVX)-induced bone loss. NOR prevents bone loss in both trabecular and cortical bone by increasing osteoblast number and phospho-S6K1 (p-S6K1) expression in osteoblasts. CONCLUSION: NOR effects in enhancing osteoblast-induced bone formation via S6K1 pathway, suggesting the potential of NOR in osteoporosis treatment by increasing bone formation.

Highly oxidized guaiane 12(8),15(6)-dilactones with neuroprotective activities from the roots of Lindera aggregata (Sims) Kosterm.

In our search for neuroprotective agents, six previously undescribed highly oxidized guaiane sesquiterpenes, linderaggrols A-F (1-6), together with three known sesquiterpenes, were isolated from the roots of Lindera aggregata (Sims) Kosterm. Their structures including absolute configurations were established by a combination of NMR spectroscopic techniques and single crystal X-ray diffraction experiments. Compounds 1-6 represented the first instances of guaiane 12(8),15(6)-dilactones. Additionally, compound 6 possessed a rare 1,8-O-bridge. Neuroprotective effects against erastin-induced ferroptosis on HT-22 cells showed that some compounds demonstrated neuroprotective effects at 20.0 µM.

Sesquiterpenoids from the roots of Lindera glauca and their cytotoxicity activities.

The chemical investigation of the roots of Lindera glauca guided the isolation and identification of 3 new sesquiterpenoids, namely glaucatotones J-L (1-3), and one known congener, (1ß,5ß)-1-hydroxyguaia-4(15),11(13)-dieno-12,5-lactone (4). The structures of new compounds were established based on comprehensive spectrographic methods, mainly including 1D & 2D NMR and HRESIMS analyses, and the absolute configurations were further confirmed by the comparison of experimental and calculated electronic circular dichroism. The cytotoxicity activities of isolates were evaluated, and the results showed that they have moderate cytotoxic activities.

[A new sesquiterpenoid from Lindera aggregata].

The chemical composition of the aqueous part of the extract from Lindera aggregata was studied, which was separated and purified by the macroporous resin column chromatography, MCI medium pressure column chromatography, semi-preparative high-performance liquid phase and other methods. The structures of the compounds were identified according to physical and chemical properties and spectroscopic data. Thirteen compounds were isolated and identified from the aqueous extracts, which were identified as(1S,3R,5R,6R,8S,10S)-epi-lindenanolide H(1), tachioside(2), lindenanolide H(3), leonuriside A(4), 3,4-dihydroxyphenyl ethyl ß-D-glucopyranoside(5), 3,4,5-trimethoxyphenol-1-O-6-α-L-rhamnose-(1→6)-O-ß-D-glucoside(6), 5-hydroxymethylfurfural(7),(+)-lyoniresin-4-yl-ß-D-glucopyranoside(8), lyoniside(9), norboldine(10), norisopordine(11), boldine(12), reticuline(13). Among them, compound 1 was a new one, and compounds 2, 5, 6, 8, 9 were obtained from L. aggregata for the first time. The inflammatory model was induced by lipopolysaccharide(LPS) in the RAW264.7 cells. The results showed that compounds 1, 8, 10 and 12 had significant anti-inflammatory activity.

Antioxidant and Anti-Inflammatory Activities of Lindera glauca Extracts.

INTRODUCTION: The current study investigated the antioxidant and anti-inflammatory effects of ethanol extracts from Lindera glauca twig (LGT) and leaf/stem (LGLS). METHODS: The antioxidant activities were measured by total content of polyphenol and flavonoid, DPPH radical scavenging, and ABTS+ radical scavenging activity. To evaluate the anti-inflammatory effect in the LPS-induced RAW 264.7 cells, protein and mRNA expression of major inflammatory factors were analyzed using Western blot analysis and RT-PCR. RESULTS: The total polyphenol content of LGT and LGLS was 88.45 ± 11.74 and 115.75 ± 7.87 GA mg/g, respectively. The total flavonoid content was 66 ± 2.89 and 74.33 ± 2.89 QE mg/g. Both LGT and LGLS showed high DPPH and ABTS+ radical scavenging activities. Neither LGT nor LGLS was cytotoxic to RAW 264.7 cells. The anti-inflammatory activities were measured by LPS-induced RAW 264.7 cells. LGT and LGLS showed inhibition of the LPS-induced production of nitric oxide (NO), inducible NO synthase, cyclooxygenase-2 at the protein and mRNA levels, as determined by Western blotting and RT-PCR, respectively. In addition, the release of tumor necrosis factor-α and interleukin-6 mRNA expression levels of these cytokines was reduced by LGT and LGLS. CONCLUSION: These results suggest that LGT and LGLS extracts have potential for use as a functional antioxidant and anti-inflammatory ingredient in cosmetic industry.

Glaucatotones A-I: Guaiane-type sesquiterpenoids from the roots of Lindera glauca with anti-inflammatory activity.

Glaucatotones A - I, nine new guaiane-type sesquiterpenoids, along with two reported compounds, namely (1ß,5ß)-1-hydroxyguaia-4(15),11(13)-dieno-12,5-lactone (10) and pseudoguaianelactone C (11), were isolated from the roots of Lindera glauca. The structures and absolute configurations of these compounds were elucidated by extensive spectroscopic analyses, single-crystal X-ray diffraction, and comparison of experimental and calculated electronic circular dichroism (ECD) data. Structurally, glaucatotone A (1) is characterized as a dihomosesquiterpenoid with an unprecedented 5/5/7/6 ring system. A pair of enantiomers, (±)-glaucatotone B (2a/2b), represent the first rearranged norsesquiterpenoid with a (cyclopentylmethyl)cyclohexane skeleton. 3 is defined as a dinorsesquiterpenoid possessing a 5/7/5 ring system. 4-6 are three guaiane-type norsesquiterpenoids. In vitro bioactivity, 2a selectively inhibited Bcap-37 with IC50 value of 5.60 µM, and 9 selectively inhibited Du-145 with IC50 value of 5.52 µM. The anti-inflammatory activity of 1-9 were tested, and of these compounds, 1, 2a, 2b and 7 exhibited potent inhibitory effects.

Rare 7,9'-dinorlignans with neuroprotective activity from the roots of Lindera aggregata (Sims) Kosterm.

Linderagatins C-F (1-4), the first examples of naturally occurring diaryltetrahydrofuran-type 7,9'-dinorlignans, were characterized from the roots of Lindera aggregata (Sims) Kosterm. The structures of these dinorlignans were elucidated by extensive spectroscopic analysis. The absolute configurations were determined based on calculated and experimental ECD data. A biosynthetic pathway for these dinorlignans was hypothetically proposed. Compounds 2 and 3 showed significant neuroprotective effects on erastin-induced ferroptosis in HT-22 cells with EC50 values of 23.4 and 21.8 µM, respectively.

[Chemical constituents of Lindera aggregata and their bioactivities: a review].

The medicinal Lindera aggregata(Lindera, Lauraceae) boasts abundant resources, which is widely used in clinical settings. It has been found that the main chemical constituents of this medicinal species are sesquiterpenoids, alkaloids, sesquiterpenoid dimers, flavonoids, and phenolic acids. Some unreported novel structures, including lindenane-type sesquiterpene dimers and trimers, have been discovered from L. aggregata in recent years. The extracts and active components of L. aggregata have anti-tumor, anti-inflammatory, antalgic, liver-protecting, antioxidant, lipid-lowering, and glucose-lowering activities, and their mechanisms of action have been comprehensively investigated. This study summarizes the research on the chemical constituents and bioactivities of L. aggregata over the past decade, which is expected to serve as a reference for the future research and utilization of L. aggregata.

Linderanidins A-F: Rare oligomeric flavonoids with an unusual C-3-C-4 linkage from the roots of Lindera erythrocarpa and their inhibitory activities on autophagy.

Autophagy is a crucial process for maintaining cellular homeostasis by degrading and recycling unnecessary or damaged cellular components. In the process of exploring autophagy regulators in plants, unique nine oligomeric flavonoids linked by the bonding of C-3 and C-4, consisting of three pairs of biflavonoids, linderanidins A-C [(+)-1/(-)-1, (+)-2/(-)-2, and (+)-3/(-)-3], and three trimeric A-type proanthocyanidins, linderanidins D-F (4-6), were isolated from the roots of Lindera erythrocarpa. The structures and absolute configurations of these compounds were determined using various techniques, such as 1D and 2D NMR, mass spectrometry, X-ray crystallography, and electronic circular dichroism. All isolates were evaluated for their ability to regulate autophagy, and compounds (±)-1-(±)-3, (-)-1-(-)-3, (+)-1-(+)-3 and 4 were found to inhibit autophagy by blocking the fusion process between autophagosome and lysosome in HEK293 cells. This study suggests that unique oligomeric flavonoids possessing a C-3-C-4 linkage derived from the roots of L. erythrocarpa are potent autophagy inhibitors.

Chemical constituents of Lindera aggregata and their bioactivities: a review / 中国中药杂志

The medicinal Lindera aggregata(Lindera, Lauraceae) boasts abundant resources, which is widely used in clinical settings. It has been found that the main chemical constituents of this medicinal species are sesquiterpenoids, alkaloids, sesquiterpenoid dimers, flavonoids, and phenolic acids. Some unreported novel structures, including lindenane-type sesquiterpene dimers and trimers, have been discovered from L. aggregata in recent years. The extracts and active components of L. aggregata have anti-tumor, anti-inflammatory, antalgic, liver-protecting, antioxidant, lipid-lowering, and glucose-lowering activities, and their mechanisms of action have been comprehensively investigated. This study summarizes the research on the chemical constituents and bioactivities of L. aggregata over the past decade, which is expected to serve as a reference for the future research and utilization of L. aggregata.

The Ethanolic Extract of Lindera aggregata Modulates Gut Microbiota Dysbiosis and Alleviates Ethanol-Induced Acute Liver Inflammation and Oxidative Stress SIRT1/Nrf2/NF-κB Pathway.

This study is an attempt to evaluate the therapeutic effect of the ethanolic extract of Lindera aggregata on the liver and intestinal microbiota in rats with alcohol-induced liver injury (ALI). Rats were treated with 70 mg probiotics, 1 g/kg, 2 g/kg, and 3 g/kg ethanolic extract of Lindera aggregata, respectively, for 10 days. We found that Lindera aggregata could significantly reduce the biochemical parameters in the serum of ALD rats. Lindera aggregata alleviates oxidative stress and inflammation by upregulating SIRT1 and Nrf2 and downregulating COX2 and NF-κB. The results of 16S rRNA gene sequencing showed that the medium dose of Lindera aggregata had the best effect on the growth of beneficial bacteria. Diversity analysis and LEfSe analysis showed that beneficial bacteria gradually occupied the dominant niche. The relative abundance of potential pathogens in the gut decreased significantly. We demonstrated that the ethanolic extract of Lindera aggregata can alleviate the oxidative stress and inflammation induced by alcohol through the SIRT1/Nrf2/NF-κB pathway and can modulate the disturbance of gut microbiota induced by alcohol intake.

Six undescribed derivatives of stilbene isolated from Lindera reflexa Hemsl. and their anti-tumor and anti-inflammatory activities.

Six undescribed stilbene derivatives Reflexanbene DH (1-4, 6) and Reflexanbene J (5), as well as one known stilbene 3,5-dimethoxystilbene (7), were isolated from the dried roots of Lindera reflexa Hemsl. Their structures and absolute configurations were elucidated using spectroscopy and electronic circular dichroism (ECD) analysis. In cytotoxic assays, moderately inhibitory activities of Reflexanbene F (3) against MGC80-3 and A549 cell lines were observed, with IC50 values of 15.42 and 5.09 µM, respectively. The IC50 value of Reflexanbene E (2) on A549 cell lines was 19.78 µM. The isolated compounds were also tested for their inhibitory effect against LPS-induced NO and IL-6 production in RAW 264.7 cells. In particular, Reflexanbene J (5) and Reflexanbene H (6) showed significant inhibition of NO production in LPS-stimulated macrophage RAW 264.7 cells at the concentration of 20 µM. Furthermore, the expression of IL-6 protein in the LPS-induced RAW 264.7 cells can also be significantly inhibited by different concentrations (5, 10 and 20 µM, p < 0.05 or p < 0.01) of compounds 1-7.

[Mechanism of Linderae Radix against gastric cancer based on network pharmacology and in vitro experimental validation].

The present study explored the main active ingredients and the underlying mechanism of Linderae Radix the treatment of gastric cancer by network pharmacology, molecular docking, and in vitro cell experiments. TCMSP, OMIM and GeneCards database were used to obtain the active ingredients of Linderae Radix to predict the related targets of both Linderae Radix and gastric cancer. After screening the common potential action targets, the STRING database was used to construct the PPI network for protein interaction of the two common targets. Enrichment analysis of GO and KEGG by DAVID database. Based on STRING and DAVID platform data, Cytoscape software was used to construct an "active ingredient-target" network and an "active ingredient-target-pathway" network. Molecular docking was performed using the AutoDock Vina to predict the binding of the active components to the key action targets, and finally the key targets and pathways were verified in vitro. According to the prediction results, there were 9 active components, 179 related targets of Radix Linderae, 107 common targets of Linderae Radix and gastric cancer, 693 biological processes, 57 cell compositions, and 129 molecular functions involved in the targets, and 161 signaling pathways involved in tumor antigen p53, hypoxia-indu-cible factor 1, etc. Molecular docking results showed that the core component, jimadone, had high binding activity with TP53. Finally, in an in vitro experiment, the screened radix linderae active ingredient gemmadone is used for preliminarily verifying the core targets and pathways of the human gastric cancer cell SGC-7901, The results showed that germacrone could significantly inhibit the proliferation of gastric cancer cells and induce the apoptosis of SGC-7901 by regulating the expression of p53, Bax, Bcl-2 and other key proteins. In summary, Radix Linderae can control the occurrence and development of gastric cancer through multi-components, multi-targets and multi-pathways, which will provide theoretical basis for further clinical discussion on the mechanism of Radix Linderae in treating gastric cancer.

Antibacterial mechanism of polysaccharides from the leaves of Lindera aggregata (Sims) Kosterm. by metabolomics based on HPLC/MS.

Lindera aggregata (Sims) Kosterm. is a traditional Chinese herb, which has been proven to have excellent antibacterial activity. In this work, we firstly extracted the polysaccharides from the leaves of Lindera aggregata (Sims) Kosterm. (LLPs), and explored their antibacterial activity and related mechanisms. The experimental results show that LLPs are a good antibacterial agent, which can damage the cell structure of bacteria and lead to the leakage of intracellular lysates. Compared with Escherichia coli (E. coli), LLPs showed better inhibitory activity against Staphylococcus aureus (S. aureus). Furthermore, the administration of LLPs not only led to the upregulation of the levels of fructose-1,6-bisphosphate (F-1,6-P) and citric acid in the glycolysis and tricarboxylic acid cycle pathways in bacteria, but also resulted in the down-regulation of the levels of oxaloacetate (OAA) and 1,3-diphosphoglycerate (1,3-BPG). This study confirmed that LLPs have good antibacterial activity, and broaden the application of the leaves of Lindera aggregata (Sims) Kosterm. in the antibacterial field. It provides ideas for exploring the antibacterial mechanism of active ingredients of Chinese herbal medicine through metabolomics.

Effects of Compounds Isolated from Lindera erythrocarpa on Anti-Inflammatory and Anti-Neuroinflammatory Action in BV2 Microglia and RAW264.7 Macrophage.

Lindera erythrocarpa contains various constituents such as cyclopentenedione-, flavonoid-, and chalcone-type components. In this study, a novel bi-linderone derivative and 17 known compounds were isolated from the leaves of L. erythrocarpa by using various chromatographic methods. The structures of the components were determined from nuclear magnetic resonance and mass spectrometry data. All isolated compounds were tested for anti-inflammatory and anti-neuroinflammatory activities in lipopolysaccharide (LPS)-induced BV2 and RAW264.7 cells. Some of these compounds showed anti-inflammatory effects by inhibiting the nitric oxide (NO) produced by LPS. In particular, linderaspirone A (16), bi-linderone (17) and novel compound demethoxy-bi-linderone (18) showed significant inhibitory effects on the production of prostaglandin E2 (PGE2), tumor necrosis factor-α, and interleukin-6. The three compounds also inhibited the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2), which are pro-inflammatory proteins, and the activation of nuclear factor κB (NF-κB). Therefore, linderaspirone A (16), bi-linderone (17), and demethoxy-bi-linderone (18) isolated from the leaves of L. erythrocarpa have therapeutic potential in neuroinflammatory diseases.

Linderasesterterpenoids A and B: Two 7-Cyclohexyldecahydroazulene Carbon Skeleton Sesterterpenoids Isolated from the Root of Lindera glauca.

Two novel sesterterpenoids linderasesterterpenoids A (1) and B (2) with an unprecedented 7-cyclohexyldecahydroazulene carbon skeleton isolated from the root of Lindera glauca. Their structures were elucidated by X-ray diffraction, quantum chemical calculations, and spectroscopic methods. The biogenetic pathway for 1 and 2 is proposed. In the bioassay, linderasesterterpenoids A and B showed good inhibitory activities against LPS-induced NO production in RAW 264.7 cells compared to a positive control.

Drug-drug interactions induced by Linderane based on mechanism-based inactivation of CYP2C9 and the molecular mechanisms.

Linderane (LDR) is a main furan-containing sesquiterpenoid of the common herbal medicine Lindera aggregata (Sims) Kosterm. Our early study indicated that LDR led to mechanism-based inactivation (MBI) of CYP2C9 in vitro, implying possible drug-drug interactions (DDIs) in clinic. In the present study, influence of LDR on the pharmacokinetics of the corresponding hydroxylated metabolites of CYP2C9 substrates in rats was investigated. Pharmacokinetic studies revealed that pretreatment with LDR at 20 mg/kg for 15 days inhibited the metabolism of both tolbutamide and warfarin catalyzed by CYP2C9. As for 4-hydroxytolbutamide, the Cmax was decreased, the t1/2z was prolonged, and the Vz/F was increased, all with significant difference. As for 7-hydroxywarfarin, the AUC0-t/AUC0-∞ and CLz/F were significantly decreased and increased, respectively. Furthermore, the underlying molecular mechanisms based on MBI of CYP2C9 by LDR were revealed. Two reactive metabolites of LDR, furanoepoxide and γ-ketoenal intermediates were identified in CYP2C9 recombinant enzyme incubation systems. Correspondingly, covalent modifications of lysine and cysteine residues of CYP2C9 protein were discovered in the CYP2C9 incubation system treated with LDR. The formation of protein adducts exhibited obvious time- and dose-dependence, which is consistent with the trend of enzyme inhibition caused by LDR in vitro. In addition to the apoprotein of CYP2C9, the heme content was significantly reduced after co-incubation with LDR. These data revealed that modification of both apoprotein and heme of CYP2C9 by reactive metabolites of LDR led to MBI of CYP2C9, therefore resulting in the inhibition of biotransformation of CYP2C9 substrates to their corresponding metabolites in vivo.