Antioxidant constituents and a new triterpenoid glycoside fromFlos Lonicerae

Chemical Constituents and LC-profile of Fresh Formosan Lonicera Japonica Flower Buds

One new secoiridoid glucoside, ethylsecologanin dimethyl acetal (1), along with 15 known compounds, comprising six iridoid glucosides (2–7), six flavonoids (8–13), two sterol glucosides (14 and 15), and chlorogenic acid (16) were isolated from the flower buds of Formosan Lonicera japonica. The structures of these isolates were determined on the basis of mass and spectroscopic analyzes. In addition, the chemical profiles of fresh Formosan honeysuckle buds and the dried Chinese one were compared by HPLC with a PDA detector. The calibration curve of the active component, chlorogenic acid, was also provided. As a result of the constituent similarity, Formosan L. japonica can be an alternative to the Chinese honeysuckles.

Screening of peroxynitrite scavengers in Flos Lonicerae by using two new methods, an HPLC-DAD-CL technique and a peroxynitrite spiking test followed by HPLC-DAD analysis

INTRODUCTION

Peroxynitrite is involved in the pathogenesis of a number of significant diseases. Peroxynitrite scavengers thus have potential application in understanding and treating these diseases. It is, therefore, important to establish screening methods able to rapidly identify peroxynitrite scavengers from herbal plants.

OBJECTIVE

To develop effective and easily operable screening methods for identifying peroxynitrite scavengers in complex matrices, including Chinese herbal medicines.

METHODS

Two simple and efficient screening methods have been developed for the identification of natural peroxynitrite scavengers in Flos Lonicerae Japonicae (FLJ). Method I used HPLC-DAD-(luminol-peroxynitrite)-CL techniques combined with Q-TOF MS/MS analysis, while Method II used pre-column reaction of the sample with peroxynitrite, followed by HPLC separation and Q-TOF MS/MS analysis.

RESULTS

Five peroxynitrite scavengers (neochlorogenic acid, chlorogenic acid, 3,4-O-dicaffeoyl quinic acid, 3,5-O-dicaffeoyl quinic acid and 4,5-O-dicaffeoyl quinic acid) were identified in FLJ using Method I. Besides the compounds identified using Method I, three additional peroxynitrite scavengers (rutin, isoquercitrin and luteoloside) were identified using Method II.

CONCLUSION

The two new methods proved to be complementary and the use of these methods should allow rapid detection of peroxynitrite-scavenging natural products from FLJ and other complex matrices.

Proteomic Analysis of Lonicera japonica Thunb. Immature Flower Buds Using Combinatorial Peptide Ligand Libraries and Polyethylene Glycol Fractionation

Lonicera japonica Thunb. flower is a well-known medicinal plant that has been widely used for the treatment of human disease. To explore the molecular mechanisms underlying the biological activities of L. japonica immature flower buds, a gel-free/label-free proteomic technique was used in combination with combinatorial peptide ligand libraries (CPLL) and polyethylene glycol (PEG) fractionation for the enrichment of low-abundance proteins and removal of high-abundance proteins, respectively. A total of 177, 614, and 529 proteins were identified in crude protein extraction, CPLL fractions, and PEG fractions, respectively. Among the identified proteins, 283 and 239 proteins were specifically identified by the CPLL and PEG methods, respectively. In particular, proteins related to the oxidative pentose phosphate pathway, signaling, hormone metabolism, and transport were highly enriched by CPLL and PEG fractionation compared to crude protein extraction. A total of 28 secondary metabolism-related proteins and 25 metabolites were identified in L. japonica immature flower buds. To determine the specificity of the identified proteins and metabolites for L. japonica immature flower buds, Cerasus flower buds were used, which resulted in the abundance of hydroxymethylbutenyl 4-diphosphate synthase in L. japonica immature flower buds being 10-fold higher than that in Cerasus flower buds. These results suggest that proteins related to secondary metabolism might be responsible for the biological activities of L. japonica immature flower buds.

Chemistry and pharmacology of the herb pair Flos Lonicerae japonicae-Forsythiae fructus

The Chinese medicine herb pair Flos Lonicerae japonicae (FLJ) and Forsythiae fructus (FF), is a representative heat-clearing (qing re) and detoxifying (jie du) combination that exhibits many pharmacological activities, including antibacterial, antiviral, antitumor, anti-inflammatory, and antioxidant effects. Extensive phytochemical studies have identified a series of bioactive compounds, such as chlorogenic acid from FLJ and forsythoside A from FF. This article provides a comprehensive review on the chemical and pharmacological principles of the traditional functions of FLJ-FF, and sheds light on further developments of this herb pair.

Protective Effect of Flos Lonicerae against Experimental Gastric Ulcers in Rats: Mechanisms of Antioxidant and Anti-Inflammatory Action

Flos Lonicerae is one of the oldest and most commonly prescribed herbs in Eastern traditional medicine to treat various inflammatory diseases. In the present study, we investigated the effects of ethyl acetate fraction of Flos Lonicerae (GC-7101) on experimental gastric ulcer models and its mechanisms of action in gastric ulcer healing. The pharmacological activity of GC-7101 was investigated in rats on HCl/EtOH, indomethacin, water immersion restraint stress induced acute gastric ulcer, and acetic-acid-induced subchronic gastric ulcer. To determine its gastroprotective mechanisms, gastric wall mucus secretion, mucosal PGE₂, mucosal NO content, nuclear translocation of NF-κB, mRNA expression of inflammatory cytokines, lipid peroxidation and glutathione content, and superoxide dismutase and catalase activities were measured. GC-7101 significantly attenuated development of acute gastric ulcer and accelerated the healing of acetic-acid-induced subchronic gastric ulcer. In HCl/EtOH-induced gastric ulcer, GC-7101 markedly enhanced gastric wall mucus content which was accompanied by increased mucosal PGE₂ and NO production. Furthermore, treatment of GC-7101 exhibited anti-inflammatory and antioxidant activities as evidenced by decreased myeloperoxidase activity, NF-κB translocation, inflammatory cytokines mRNA expression, and lipid peroxidation and increased glutathione content and superoxide dismutase and catalase activities. These results demonstrated that GC-7101 possesses strong antiulcerogenic effect by modulating oxidative stress and proinflammatory mediators.

Anti-inflammatory and antipruritic effects of luteolin from Perilla (P. frutescens L.) leaves

Perilla (Perilla frutescens L.) leaves have shown therapeutic efficacy in the treatment of inflammatory disorders, allergies, bronchial asthma, and systemic damage due to free radicals. In the present study we analyzed the active constituents in perilla leaves using high-performance liquid chromatography (HPLC) and isolated luteolin, a polyphenolic flavonoid. We investigated the anti-inflammatory and antipruritic properties of luteolin. Luteolin inhibited the secretion of inflammatory cytokines such as interleukin-1β (IL-1 β) and tumor necrosis factor-α (TNF-α) from human mast cells (HMC-1) stimulated with phorbol myristate acetate plus calcium ionophore A23187 in a dose-dependent manner. Luteolin also significantly reduced the histamine release from rat peritoneal mast cells stimulated by compound 48/80, a potent histamine liberator. Furthermore, the administration of luteolin markedly inhibited the scratching behavior and vascular permeability induced by pruritogens, such as compound 48/80 or serotonin, in ICR mice. These results suggested that luteolin has potential as a therapeutic agent against inflammation and itch-related skin diseases.

Site-specific anticancer effects of dietary flavonoid quercetin

Food-derived flavonoid quercetin, widely distributed in onions, apples, and tea, is able to inhibit growth of various cancer cells indicating that this compound can be considered as a good candidate for anticancer therapy. Although the exact mechanism of this action is not thoroughly understood, behaving as antioxidant and/or prooxidant as well as modulating different intracellular signalling cascades may all play a certain role. Such inhibitory activity of quercetin has been shown to depend first of all on cell lines and cancer types; however, no comprehensive site-specific analysis of this effect has been published. In this review article, cytotoxicity constants of quercetin measured in various human malignant cell lines of different origin were compiled from literature and a clear cancer selective action was demonstrated. The most sensitive malignant sites for quercetin revealed to be cancers of blood, brain, lung, uterine, and salivary gland as well as melanoma whereas cytotoxic activity was higher in more aggressive cells compared to the slowly growing cells showing that the most harmful cells for the organism are probably targeted. More research is needed to overcome the issues of poor water solubility and relatively low bioavailability of quercetin as the major obstacles limiting its clinical use.

Stability and accuracy assessment of identification of traditional Chinese materia medica using DNA barcoding: a case study on Flos Lonicerae Japonicae

DNA barcoding is a novel molecular identification method that aids in identifying traditional Chinese materia medica using traditional identification techniques. However, further study is needed to assess the stability and accuracy of DNA barcoding. Flos Lonicerae Japonicae, a typical medicinal flower, is widely used in China, Korea, and other Southeast Asian countries. However, Flos Lonicerae Japonicae and its closely related species have been misused and traded at varying for a wide range of prices. Therefore, Flos Lonicerae Japonicae must be accurately identified. In this study, the ITS2 and psbA-trnH regions were amplified by polymerase chain reaction (PCR). Sequence assembly was performed using CodonCode Aligner V 3.5.4. The intra- versus inter-specific variations were assessed using six metrics and "barcoding gaps." Species identification was conducted using BLAST1 and neighbor-joining (NJ) trees. Results reveal that ITS2 and psbA-trnH exhibited an average intraspecific divergence of 0.001 and 0, respectively, as well as an average inter-specific divergence of 0.0331 and 0.0161. The identification efficiency of ITS2 and psbA-trnH evaluated using BLAST1 was 100%. Flos Lonicerae Japonicae was formed into one clade through the NJ trees. Therefore, Flos Lonicerae Japonicae can be stably and accurately identified through the ITS2 and psbA-trnH regions, respectively.

Transcriptome analysis of buds and leaves using 454 pyrosequencing to discover genes associated with the biosynthesis of active ingredients in Lonicera japonica Thunb

BACKGROUND

Lonicera japonica Thunb. is a plant used in traditional Chinese medicine known for its anti-inflammatory, anti-oxidative, anti-carcinogenic, and antiviral pharmacological properties. The major active secondary metabolites of this plant are chlorogenic acid (CGA) and luteoloside. While the biosynthetic pathways of these metabolites are relatively well known, the genetic information available for this species, especially the biosynthetic pathways of its active ingredients, is limited.

METHODOLOGY/PRINCIPAL FINDINGS

We obtained one million reads (average length of 400 bp) in a whole sequence run using a Roche/454 GS FLX titanium platform. Altogether, 85.69% of the unigenes covering the entire life cycle of the plant were annotated and 325 unigenes were assigned to secondary metabolic pathways. Moreover, 2039 unigenes were predicted as transcription factors. Nearly all of the possible enzymes involved in the biosynthesis of CGA and luteoloside were discovered in L. japonica. Three hydroxycinnamoyl transferase genes, including two hydroxycinnamoyl-CoA quinate hydroxycinnamoyl transferase genes and one hydroxycinnamoyl-CoA shikimate/quinate hydroxycinnamoyl transferase (HCT) gene featuring high similarity to known genes from other species, were cloned. The HCT gene was discovered for the first time in L. japonica. In addition, 188 candidate cytochrome P450 unigenes and 245 glycosyltransferase unigenes were found in the expressed sequence tag (EST) dataset.

CONCLUSION

This study provides a high quality EST database for L. japonica by 454 pyrosequencing. Based on the EST annotation, a set of putative genes involved in CGA and luteoloside biosynthetic pathways were discovered. The database serves as an important source of public information on genetic markers, gene expression, genomics, and functional genomics in L. japonica.

Chemical and biological evaluation of nephrocizin in protecting nerve growth factor-differentiated PC12 cells by 6-hydroxydopamine-induced neurotoxicity

The neurotoxin 6-hydroxydopamine (6-OHDA) has been widely used to generate an experimental model of Parkinson's disease. This model is crucial in the search for compounds that diminish 6-OHDA-induced nerve growth factor (NGF)-differentiated PC12 cell death. Nephrocizin (luteolin-7-O-β-D-glucopyranoside), a flavone glycoside, was isolated from widely distributed plants. The protective effects of pre-treatment with nephrocizin on the induced neurotoxicity in PC12 cells by 6-OHDA and its oxidative products, H₂O₂-, and p-quinone, were evaluated herein. Nephrocizin promoted cell viability, scavenged ROS-related products, increased cellular glutathione (GSH) levels, and reduced caspase-3 and -8 activities in 6-OHDA-, H₂O₂-, or p-quinone-treated PC12 cells. Furthermore, nephrocizin-conjugated metabolites in PC12 cells were identified with the boronate-affinity method and LC-MS technology, and preferential regioselectivity at the C2' and C5' positions by the nephrocizin-GSH (or NAC) adduct method was observed. These lines of evidence established that nephrocizin could form a dimer to diminish the intracellular ROS. These results demonstrate the first neuroprotective mechanism of nephrocizin against 6-OHDA-, H₂O₂- or p-quinone-induced cytotoxicity in PC12 cells via chemical and biological studies. These dietary antioxidants are potential candidates for use in intervention in neurodegenerative diseases.

Prophylactic effects of Lonicera japonica extract on dextran sulphate sodium-induced colitis in a mouse model by the inhibition of the Th1/Th17 response

Inflammatory bowel diseases (IBD) are chronically relapsing inflammatory disorders of the intestine. Although some therapeutic agents, including steroids, are available for the treatment of IBD, these agents have limited use. Therefore, dietary supplements have emerged as possible interventions for IBD. Japanese honeysuckle flower, the flower of Lonicera japonica, is a well-known dietary supplement and has been used to prevent or treat various inflammatory diseases. In the present study, we investigated the effects of L. japonica on experimental murine colitis. Colitis was induced by 5 % dextran sulphate sodium (DSS) in Balb/c mice. The water extract of L. japonica (LJE) at doses of 20, 100 or 500 mg/kg was orally administered to mice twice per day for 7 d. Body weight, colon length and a histological damage score were assessed to determine the effects on colitis. Cytokine profiles were assessed to examine the effects on helper T (Th) cell-related immunological responses. In addition, CD4+CD25+Foxp3+T cells were analysed in vivo and in vitro for investigating the effects on regulatory T (Treg) cells. LJE showed dose-dependent inhibitory effects against colon shortening, weight loss and histological damage. LJE down-regulated IL-1β, TNF-α, interferon-γ, IL-6, IL-12 and IL-17. However, LJE did not show any significant effects on IL-10, IL-23, transforming growth factor-β1 and Treg cell populations. In conclusion, LJE showed protective effects against DSS-induced colitis via the Th1/Th17 pathway and not via Treg cell-related mechanisms.

Lonicera japonica Thunb.: ethnopharmacology, phytochemistry and pharmacology of an important traditional Chinese medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Lonicera japonica Thunb. (Caprifoliaceae), a widely used traditional Chinese medicine, was known as Jin Yin Hua (Chinese: ), Ren Dong and Japanese honeysuckle. It was taken to treat the exopathogenic wind-heat, epidemic febrile diseases, sores, carbuncles and some infectious diseases. At the same time, Lonicera japonica could be used as healthy food, cosmetics, ornamental groundcover, and so on.

AIM OF THE REVIEW

The present paper reviewed the ethnopharmacology, the biological activities, toxicology and phytochemistry of Lonicera japonica.

MATERIALS AND METHODS

Information on Lonicera japonica was gathered via the Internet (using Google Scholar, Baidu Scholar, Elsevier, ACS, Medline Plus, CNKI and Web of Science) and libraries. Additionally, information also was obtained from some local books and brilliant scholars on ethnopharmacology.

RESULTS

More than 140 chemical compounds have been isolated, and the main compositions are essential oils, organic acids and flavones, etc. Lonicera japonica and its active principles possess wide pharmacological actions, such as anti-inflammatory, antibacterial, antiviral, antioxidative and hepatoprotective activities.

CONCLUSIONS

As an important traditional Chinese medicine, further studies on Lonicera japonica can lead to the development of new drugs and therapeutics for various diseases, and how to utilize it better should be paid more attentions.

The protective role of 5-hydroxymethyl-2-furfural (5-HMF) against acute hypobaric hypoxia

Our previous study showed that pretreatment with 5-hydroxymethyl-2-furfural (5-HMF) led to protection against hypoxic injury via a p-ERK-mediated pathway in vitro. Whether the protection of 5-HMF against hypoxia is effective in vivo is unknown. The present study is aimed to verify the role of 5-HMF in acute hypobaric hypoxia using Kunming mice as an in vivo model and further investigate the underlying mechanisms. Mice pretreated with or without 5-HMF for 1 h were exposed to acute hypobaric hypoxic condition for 6 h and then the survival time, the survival rate, the permeability of blood-brain barrier (BBB), the histological analysis in hippocampus and cortex, and the phosphorylation level of mitogen-activated protein kinases (ERK, JNK, and p38) were investigated. The results showed that 5-HMF significantly increased the survival time and the survival rate of mice. Accordingly, pretreatment with 5-HMF markedly attenuated acute hypobaric hypoxia-induced permeability of BBB (P < 0.01). In addition, the cellular damage extent of the hippocampus and the cortex induced by hypoxia for 6 h was also attenuated by pretreatment with 5-HMF, especially in the hippocampus CA1 region. Furthermore, the activation of ERK rather than JNK and p38 was involved in the protection of 5-HMF against acute hypobaric hypoxia. In summary, 5-HMF enhanced the survival capability of mice and decreased acute hypoxic damage to the brain, which may be associated with the effects on BBB and p-ERK.

Identification and quantification of free radical scavengers in the flower buds of Lonicera species by online HPLC-DPPH assay coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry

Flos Lonicerae, derived from the flower buds of several medicinal Lonicera species, is a commonly used herbal medicine with multiple pharmacological activities, one of the major ones being antioxidant activity. In this study, free radical scavengers in the flower buds of six Lonicera species were screened, identified and quantified by online HPLC-DPPH (1,1-diphenyl-2-picrylhydrazyl) assay coupled with LC quadrupole time-of-flight tandem mass spectrometry (Q-TOF MS/MS). The antioxidants were firstly screened from the complex plant matrix by the online HPLC-DPPH assay. Then the active compounds were identified by LC Q-TOF MS/MS, and the possible fragmentation pathways were proposed. The reactivity of antioxidants available was investigated using an internal standard method by online LC assay. The contents of 12 antioxidants were also determined or estimated by HPLC coupled with diode array detector. The total antioxidant capability determined by the online method was used as the marker to evaluate the quality of Flos Lonicerae. The results were important to clarify the material basis and therapeutic mechanism of Flos Lonicerae.

Chemical correlation between Shuanghuanglian injection and its three raw herbs by LC fingerprint

Shuanghuanglian injection, a famous composite formula in China, is a combination of Flos lonicerae japonicae, Radix scutellariae and Fructus forsythiae. To develop a method to overall evaluate the correlation between the formula and its three raw herbs, the representative LC fingerprint of Shuanghuanglian injection was established from 12 batches of samples. Ten peaks were selected as the common peaks to evaluate the similarities of different samples from different manufacturers. Hierarchical clustering analysis was used as a powerful pattern recognition tool to identify and classify Shuanghuanglian injection from different factories. In addition, chemical correlation between the formula and the three raw herbs was evaluated qualitatively through comparison of their chromatograms under the same HPLC conditions. The results showed that peak 1, 2, 3 and 9 in the formula fingerprint were characteristic components of Flos lonicerae japonicae, peaks 5, 6 and 8 were that of F. forsythiae, peak 10 was that of R. scutellariae, while peak 7 was the common component of Flos lonicerae japonicae and F. forsythiae, peak 4 was addressed to F. forsythiae and it was also the product of the manufacturing procedure.

Luteolin isolated from the medicinal plant Elsholtzia rugulosa (Labiatae) prevents copper-mediated toxicity in β-amyloid precursor protein Swedish mutation overexpressing SH-SY5Y cells

Luteolin, a 3',4',5,7-tetrahydroxyflavone, is a plant flavonoid and pharmacologically active agent that has been isolated from several plant species. In the present study, the effects of luteolin obtained from the medicinal plant Elsholtzia rugulosa and the related mechanisms were examined in an Alzheimer's disease (AD) cell model. In this model, copper was used to exacerbate the neurotoxicity in β-amyloid precursor protein Swedish mutation stably overexpressed SH-SY5Y cells (named "APPsw cells" for short). Based on this model, we demonstrated that luteolin increased cell viability, reduced intracellular ROS generation, enhanced the activity of SOD and reversed mitochondrial membrane potential dissipation. Inhibition of caspase-related apoptosis was consistently involved in the neuroprotection afforded by luteolin. Furthermore, it down-regulated the expression of AβPP and lowered the secretion of Aβ₁₋₄₂. These results indicated that luteolin from the Elsholtzia rugulosa exerted neroprotective effects through mechanisms that decrease AβPP expression, lower Aβ secretion, regulate the redox imbalance, preserve mitochondrial function, and depress the caspase family-related apoptosis.

Anti-angiogenic, antinociceptive and anti-inflammatory activities of Lonicera japonica extract

This study aimed to elucidate some novel pharmacological activities of Lonicera japonica (Caprifoliaceae), which is widely used in Oriental folk medicine. The ethanolic extract of L. japonica (LJ) dose dependently inhibited chick chorioallantoic membrane angiogenesis. The antinociceptive activity of LJ was assessed using the acetic acid-induced constriction model in mice. LJ showed anti-inflammatory activity in two in-vivo models: the vascular permeability and air pouch models. LJ suppressed the production of nitric oxide via down-regulation of inducible nitric oxide synthase in lipopolysaccharide-stimulated RAW264.7 macrophage cells. However, LJ was unable to suppress induction of cyclooxygenase-2 in the stimulated macrophage cells. LJ decreased the reactive oxygen species level in the stimulated macrophage cells. In brief, the flowers of L. japonica possess potent anti-angiogenic and antinociceptive activities, in addition to anti-inflammatory activity, which partly supports its therapeutic efficacy.

Luteolin isolated from the flowers of Lonicera japonica suppresses inflammatory mediator release by blocking NF-kappaB and MAPKs activation pathways in HMC-1 cells

Luteolin (3′,4′,5,7-tetrahydroxylflavone) is a plant flavonoid and pharmacologically active agent that has been isolated from several plant species. In the present study, the effect of luteolin from the flowers of Lonicera japonica on phorbol 12-myristate 13-acetate (PMA) plus A23187-induced mast cell activation was examined. Luteolin significantly inhibited the induction of inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-8, IL-6 and granulocyte-macrophage colony-stimulating factor (GM-CSF) by PMA plus A23187. Moreover, luteolin attenuated cyclooxygenase (COX)-2 expression and intracellular Ca²⁺ levels. In activated HMC-1 cells, the phosphorylation of extra-signal response kinase (ERK 1/2) and c-jun N-terminal Kinase (JNK 1/2), but not p38 mitogen-activated protein kinase (p38 MAPK) were decreased by treatment of the cells with luteolin. Luteolin inhibited PMA plus A23187-induced nuclear factor (NF)-κB activation, IκB degradation, and luciferase activity. Furthermore, luteolin suppressed the expression of TNF-α, IL-8, IL-6, GM-CSF, and COX-2 through a decrease in the intracellular Ca²⁺ levels, and also showed a suppression of the ERK 1/2, JNK 1/2, and NF-κB activation. These results indicated that luteolin from the flowers of Lonicera japonica exerted a regulatory effect on mast cell-mediated inflammatory diseases, such as RA, allergy disease and IBD.

Triterpenoids

This review covers the isolation and structure determination of triterpenoids including squalene derivatives, protostanes, lanostanes, holostanes, cycloartanes, dammaranes, euphanes, tirucallanes, tetranortriterpenoids, lupanes, oleananes, friedelanes, ursanes, hopanes, isomalabaricanes and saponins; 574 references are cited.

Effect of Lonicerae Flos extracts on reflux esophagitis with antioxidant activity

AIM: To observe the effects of traditional antiinflammatory medicine Lonicerae Flos (LF) on rat reflux esophagitis (RE) induced by pylorus and forestomach ligation compared with the well-known proton antioxidant, α-tocopherol.

METHODS: Rats were pretreated with three different dosages of LF (500, 250 and 125 mg/kg) orally, once a day for 14 d before pylorus and forestomach ligation. Nine hours after pylorus and forestomach ligation, changes to the stomach and esophagus lesion areas, gastric volumes, acid and pepsin outputs, antioxidant effects, esophageal lipid peroxidation, superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), myeloperoxidase and glutathione (GSH) levels, and collagen contents (marker of flexibility) were observed on the esophageal and fundic histopathology. The results were compared with an α-tocopherol (once orally, 1 h before operation, 30 mg/kg) treated group in which the effects on RE were already confirmed.

RESULTS: Pylorus and forestomach ligations caused marked increases of gross esophageal and gastric mucosa lesion areas, which corresponded with histopathological changes. In addition, increases of esophageal lipid peroxidation, decreases of SOD, CAT, and GSH-free radical scavengers, increases of collagen were observed. However, these pylorus and forestomach ligation induced RE were dose-dependently inhibited by treatment of 500, 250 and 125 mg/kg of LF extract, mediated by antioxidant effects. RE at 250 mg/kg showed similar effects α-tocopherol.

CONCLUSION: The results suggest that antioxidant effects of LF could attenuate the severity of RE and prevent the esophageal mucosal damage, and validate its therapeutic use in esophageal reflux disease.

Luteolin inhibits adipogenic differentiation by regulating PPARgamma activation

Luteolin (3',4',5,7-tetrahydroxyflavone), a flavonoid, has been known to possess antimutagenic, antitumorigenic, antioxidant, and anti-inflammatory properties. In this study, we investigated the role of luteolin in the regulation of adipogenic differentiation in 3T3-L1 preadipocytes. Luteolin inhibited intracellular triglyceride accumulation in a dose-dependent manner without cytotoxicity. Western blot and reverse transcription-polymerase chain reaction analyses showed that this inhibition was accompanied by attenuated expression of the adipogenic transcription factors: peroxisome proliferator-activated receptor gamma (PPARgamma) and CCAAT/enhancer-binding protein alpha. Luteolin inhibited the PPARgamma transactivation stimulated by rosiglitazone, a synthetic agonist, in COS-7 cells and inhibited rosiglitazone-induced adipogenic differentiation in 3T3-L1 cells. These data suggest that luteolin exerts antiadipogenic effects by suppressing adipogenic transcription factors and by inhibiting the transactivation of PPARgamma.

Rapid and simple method for screening of natural antioxidants from Chinese herb Flos Lonicerae Japonicae by DPPH-HPLC-DAD-TOF/MS

A rapid and simple method has been developed for the screening and identification of natural antioxidants of Flos Lonicerae Japonicae (FLJ), derived from the flower buds of Lonicera japonica. The hypothesis is that upon reaction with 1,1-diphenyl-2-picrylhydrazyl (DPPH), the peak areas (PAs) of compounds with potential antioxidant effects in the HPLC chromatograms will be significantly reduced or disappeared, and the identity confirmation could be achieved by HPLC-DAD-TOF/MS hyphenated technique. Using the proposed approach, about 14 compounds in the FLJ extract were found to possess a potential antioxidant activity. They were identified as chlorogenic acid (1), 1-O-caffeoylquinic acid (1-O-CQA, 2), caffeic acid (4), 4-O-CQA (5), rutin (7), isoquercitrin (8), luteolin-7-O-glucoside (9), lonicerin (10), 4,5-O-dicaffeoylquinic acid (4,5-O-diCQA, 11), 3,5-O-diCQA (12), 1,3-O-diCQA (13), 3,4-O-diCQA (14), 1,4-O-diCQA (16), and luteolin (17). In addition, the free radical scavenging capacities of the available identified compounds were also investigated by HPLC assay. The results indicated that the compounds with PAs significantly decreasing were natural antioxidants, whereas those with PAs not changing presented no activities, which accordingly indicated that this newly proposed method could be widely applied for rapid screening and identification of natural antioxidants from complex matrices including Chinese herbal medicines.

Triterpenoid saponins from the seeds of Pharbitis nil

From the seeds of Pharbitis nil (Convolvulaceae), two new oleanene-type triterpene glycosides, pharbitosides A (1) and B (2), together with beta-sitosterol, beta-sitosterol glucoside (daucosterol), caffeic acid, and methyl caffeate were isolated. The structure of pharbitoside A (1) was elucidated to be queretaroic acid 3-O-alpha-L-rhamnopyranosyl-(1-->2)-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranoside (1). Pharbitoside B (2) is a 21alpha-hydroxyoleanolic acid saponin carrying the same sugar moiety as that of pharbitoside A (1).