Uncovering nutritional metabolites and candidate genes involved in flavonoid metabolism in Houttuynia cordata through combined metabolomic and transcriptomic analyses.

The perennial herb Houttuynia cordata has long been cultivated and used as medicinal and edible plant in Asia. Nowadays, increasing attention is attracted due to its numerous health benefits. Flavonoids are the main chemical constituents exerting pharmacological activities. In the present study, we investigated both metabolome and transcriptome of two H. cordata accessions (6# and 7#) with distinct flavonoids contents. In total 397 metabolites, i.e., 220 flavonoids, 92 amino acids and derivatives, 20 vitamins, and 65 saccharides were abundant in aboveground part. Cyanidin-3-O-rutinoside and quercetin-3-O-galactoside were the most abundant flavonoids, which can be categorized into seven classes, namely anthocyanidins, chalcones, flavanols, flavanones, flavanonols, flavones, and flavonols. Flavonols was the most abundant group. Contents of 112 flavonoids differed significantly between the two accessions, with catechin-(7,8-bc)-4α-(3,4-dihydroxyphenyl)-dihydro-2-(3H)-one, cinchonain Id, and cinchonain Ic being the dominant flavonoid metabolites among them. Pinocembrin-7-O-neohesperidoside, pinocembrin-7-O-rutinoside, and kaempferol-3-O-galactoside-4'-O-glucoside were uniquely abundant in accession 7. Transcriptome data revealed a total of 110 different expressed genes related to flavonoid metabolism, with more highly expressed genes observed in 7#. We annotated a total of 19 differential flavonoid metabolites and 34 differentially expressed genes that are associated with the flavonoid metabolic network. Based on the transcriptome and qPCR data a total of 8 key candidate genes involved in flavonoid metabolism were identified. The ANS gene were found to play an important role in the synthesis of cyanidin-3-O-glucoside, while the CHI, F3'H and FLS genes were mainly responsible for controlling the levels of flavanones, flavones, and flavonols, respectively. Collectively, the present study provides important insights into the molecular mechanism underlying flavonoid metabolism in H. cordata.

Identifying the Potential of miRNAs in Houttuynia cordata-Derived Exosome-Like Nanoparticles Against Respiratory RNA Viruses.

Introduction: Pathogenic respiratory RNA viruses, including influenza A virus (IAV), respiratory syncytial virus (RSV), and SARS-CoV-2, are major causes of causes of acute respiratory infection globally. Plant-derived exosome-like nanoparticles containing miRNAs have shown substantial cross-kingdom regulatory effects on both viral and human transcripts. Houttuynia cordata (H. cordata), a traditional Chinese medicine frequently used to treat respiratory diseases. However, the role of H. cordata-derived exosome-like nanoparticles (HELNs) and the miRNA they encapsulated are unclear. Methods: HELNs were isolated from fresh underground roots (uHELNs) and above ground stems and leaves (aHELNs) using differential centrifugation. The HELNs were identified using transmission electron microscopy, nanoparticle tracking analysis, and zeta potential. Small RNA sequencing and RT-PCR were employed to determine the miRNA expression in uHELNs and aHELNs. All genomes were sourced from the NCBI database. Target prediction of viral genomes was performed using RNAhybrid, while human target prediction was conducted using both RNAhybrid and Miranda. Functional enrichment analysis was applied to the predicted human targets to explore the hub targets and their roles in antiviral effects. The accessibility of miRNA target sites was determined through the MFOLD web server, and customized dual-luciferase reporter assays were administered to validate the computational findings. Results: A total of 12 highly enriched miRNAs were identified in both uHELNs and aHELNs. Upon prediction and verification, miR858a and miR858b were shown to target the NP gene in H1N1, while miR166a-3p targeted the ORF1ab in SARS-CoV-2. However, no valid miRNA targets were found for RSV. Regarding human transcripts, miR168a-3p, miR168b-3p, and miR8175 were found to inhibit MAPK3 expression, and novel_mir2 could suppress both AKT1 and MAPK3 expression. Discussion: This study sheds light on the collaborative antiviral mechanism of miRNAs in HELNs across two species and explores the potential antiviral scopes of both H. cordata miRNAs and HELNs.

Hydroalcoholic root extracts of Houttuynia cordata (Thunb.) standardized by UPLC-Q-TOF-MS/MS promotes apoptosis in human hepatocarcinoma cell HepG2 via GSK-3ß/ß-catenin/PDL-1 axis.

Houttuynia cordata (Thunb.), an important medicinal plant of Northeast India, Korea, and China, is used to treat various ailments and for anticancer research. Knowing its traditional practices, we are interested in the mode-of-action of HCT on HepG2 to co-relate the traditional practice with modern drug therapeutics. UPLC-Q-ToF-Ms analysis of HCT reveals identification of 14 metabolites. Network pharmacology analysis of the 14 compounds showed interaction with 232 different targets with their potential involvement in hepatocellular carcinoma. Whole extracts impart cytotoxicity on variety of cell lines including HepG2. There was a significant morphological alteration in treated HepG2 cells due to impairment of cytoskeletal components like ß and γ- tubulin. Arrest at G1-S checkpoint was clearly indicated downregulation of Cyclin D1. The root extracts actuated apoptosis in HepG2 as evident from altered mitochondrial membrane potential, Annexin V- FITC, BrdU-PI, AO/EtBr assays, and modulations of apoptotic protein expression but without ROS generation. Whole extracts caused abrogation of epithelial to mesenchymal transition with repression of Snail, N-Cadherin, Vimentin, MMP-9, and upregulation of Pan-Cadherin. Pathway analysis found GSK-3ß in Wnt/ß-Catenin signaling cascade to be involved through Hepatocellular carcinoma (hsa05225) pathway. The GSK-3ß/ß-Catenin/PDL-1 signaling was found to be inhibited with the downregulation of pathway components. This was further confirmed by application of EGF, an inducer of the GSK-3ß/ß-Catenin pathway that neutralized the effect of Houttuynia cordata (Thunb.) root extract on the said pathway. Network pharmacology analysis also confirms the synergy network with botanical-bioactive-target-disease which showed Kaempferol to have the highest degree of association with the said pathway.

Targeting calcium signaling by inositol trisphosphate receptors: A novel mechanism for the anti-asthmatic effects of Houttuynia cordata.

Asthma is a chronic inflammatory disease characterized by airway hypersensitivity and remodeling. The current treatments provide only short-term benefits and may have undesirable side effects; thus, alternative or supplementary therapy is needed. Because intracellular calcium (Ca2+) signaling plays an essential role in regulating the contractility and remodeling of airway smooth muscle cells, the targeting of Ca2+ signaling is a potential therapeutic strategy for asthma. Houttuynia cordata is a traditional Chinese herb that is used to treat asthma due to its anti-allergic and anti-inflammatory properties. We hypothesized that H. cordata might modulate intracellular Ca2+ signaling and could help relieve asthmatic airway remodeling. We found that the mRNA and protein levels of inositol trisphosphate receptors (IP3Rs) were elevated in interleukin-stimulated primary human bronchial smooth muscle cells and a house dust mite-sensitized model of asthma. The upregulation of IP3R expression enhanced intracellular Ca2+ release upon stimulation and contributed to airway remodeling in asthma. Intriguingly, pretreatment with H. cordata essential oil rectified the disruption of Ca2+ signaling, mitigated asthma development, and prevented airway narrowing. Furthermore, our analysis suggested that houttuynin/2-undecanone could be the bioactive component in H. cordata essential oil because we found similar IP3R suppression in response to the commercially available derivative sodium houttuyfonate. An in silico analysis showed that houttuynin, which downregulates IP3R expression, binds to the IP3 binding domain of IP3R and may mediate a direct inhibitory effect. In summary, our findings suggest that H. cordata is a potential alternative treatment choice that may reduce asthma severity by targeting the dysregulation of Ca2+ signaling.

Therapeutic effects on H1N1-induced pneumonia in mice and intestinal bacteria biotransformation of four main flavonoids from Houttuynia cordata Thunb.

Flavonoids widely exist in a large number of Chinese herbal medicines with antiviral and anti-inflammatory properties. Houttuynia cordata Thunb. is a traditional Chinese herbal medicine for heat-clearing and detoxification. In our previous research, total flavonoids from H. cordata (HCTF) effectively alleviated H1N1-induced acute lung injury (ALI) in mice. In this study, 8 flavonoids were recognized from HCTF (containing 63.06 % ± 0.26 % of total flavonoids, as quercitrin equivalents) by UPLC-LTQ-MS/MS. Four main flavonoid glycosides in HCTF (rutin, hyperoside, isoquercitrin and quercitrin) and their common aglycone quercetin (100 mg/kg) all showed therapeutic effects on H1N1-induced ALI in mice. The two flavonoids (hyperoside and quercitrin) with higher contents and quercetin showed stronger therapeutic effects on H1N1-induced ALI in mice. Hyperoside, quercitrin and quercetin significantly reduced the levels of pro-inflammatory factors, chemokines, or neuraminidase activity compared with the same dose of HCTF (p < 0.05). The results of mice intestinal bacteria biotransformation in vitro showed that quercetin was the main metabolite. The conversion rates of hyperoside and quercitrin were significantly higher by the intestinal bacteria under the pathological state (0.81 ± 0.02 and 0.91 ± 0.01, respectively) than normal state (0.18 ± 0.01 and 0.18 ± 0.12, respectively, p < 0.001). Our findings showed that hyperoside and quercitrin were the main efficacious components of HCTF for treating H1N1-induced ALI in mice and could be metabolized to quercetin by intestinal bacteria in pathological state to exert their effects.

Aerial part of Houttuynia cordata reverses memory impairment by regulating amyloid beta accumulation and neuroinflammation in Alzheimer's disease model.

Alzheimer's disease (AD) is the most common neurodegenerative disease characterized by amyloid-ß (Aß) deposition, accompanied by neuroinflammation and memory dysfunction. Houttuyniae Herba (aerial parts of Houttuynia cordata, also known as fish mint; HH), an herbal medicine traditionally used to treat fever, urinary disorders, and pus, is revealed to protect neurons from Aß toxicity and regulate cholinergic dysfunction in AD models. In this study, we aimed to investigate the effects of HH on excessive accumulation of Aß followed by neuroinflammation, synaptic degeneration, and memory impairment. Two-month-old 5xFAD transgenic mice were administered HH at 100 mg/kg for 4 months. We observed that HH treatment ameliorated memory impairment and reduced Aß deposits in the brains of the mice. HH directly inhibited Aß aggregation in vitro using the Thioflavin T assay and indirectly suppressed the amyloidogenic pathway by increasing alpha-secretase expression in the mice brain. In addition, HH exerted antineuroinflammatory effects by reducing of glial activation and p38 phosphorylation. Moreover, HH treatment increased the expression of synaptophysin, a presynaptic marker protein. Overall, HH alleviates memory impairment in AD by facilitating nonamyloidogenic pathway and inhibiting neuroinflammation. Therefore, we suggest that HH can be a promising herbal drug for patients with AD requiring multifaceted improvement.

Combination of Houttuynia cordata polysaccharide and Lactiplantibacillus plantarum P101 alleviates acute liver injury by regulating gut microbiota in mice.

BACKGROUND: Polysaccharides and probiotics can play an outstanding role in the treatment of liver disease by regulating gut microbiota. Recently, the combined therapeutic effect of probiotics and polysaccharides has attracted the attention of researchers. Houttuynia cordata polysaccharide (HCP) combined with Lactiplantibacillus plantarum P101 was used to prevent carbon tetrachloride (CCl4 )-induced acute liver injury (ALI) in mice, and its effect on gut microbiota regulation was explored. RESULTS: Results showed that, in mice, HCP combined with L. plantarum P101 significantly alleviated oxidative stress and inflammatory injury in the liver by activating Nrf2 signals and inhibiting NF-κB signals. The analysis of gut microbiota revealed that the combination of HCP and L. plantarum P101 increased the abundance of beneficial bacteria such as Alloprevotella, Roseburia, and Akkermansia, but reduced that of the pro-inflammatory bacteria Alistipes, Enterorhabdus, Anaerotruncus, and Escherichia-Shigella. Correlation analysis also indicated that the expression of Nrf2 and TLR4/NF-κB was connected to the changes in gut microbiota composition. Houttuynia cordata polysaccharide combined with L. plantarum P101 can regulate the gut microbiota and then mediate the gut-liver axis to activate the antioxidant pathway and inhibit inflammatory responses, thereby alleviating CCl4 -induced ALI. CONCLUSION: Our study provided a new perspective on the use of polysaccharides combined with probiotics in the treatment of liver disease. © 2022 Society of Chemical Industry.

Identification of phytocompounds from Houttuynia cordata Thunb. as potential inhibitors for SARS-CoV-2 replication proteins through GC-MS/LC-MS characterization, molecular docking and molecular dynamics simulation.

The COVID-19 pandemic caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a massive viral disease outbreak of international concerns. The present study is mainly intended to identify the bioactive phytocompounds from traditional antiviral herb Houttuynia cordata Thunb. as potential inhibitors for three main replication proteins of SARS-CoV-2, namely Main protease (Mpro), Papain-Like protease (PLpro) and ADP ribose phosphatase (ADRP) which control the replication process. A total of 177 phytocompounds were characterized from H. cordata using GC-MS/LC-MS and they were docked against three SARS-CoV-2 proteins (receptors), namely Mpro, PLpro and ADRP using Epic, LigPrep and Glide module of Schrödinger suite 2020-3. During docking studies, phytocompounds (ligand) 6-Hydroxyondansetron (A104) have demonstrated strong binding affinity toward receptors Mpro (PDB ID 6LU7) and PLpro (PDB ID 7JRN) with G-score of - 7.274 and - 5.672, respectively, while Quercitrin (A166) also showed strong binding affinity toward ADRP (PDB ID 6W02) with G-score -6.788. Molecular Dynamics Simulation (MDS) performed using Desmond module of Schrödinger suite 2020-3 has demonstrated better stability in the ligand-receptor complexes A104-6LU7 and A166-6W02 within 100 ns than the A104-7JRN complex. The ADME-Tox study performed using SwissADMEserver for pharmacokinetics of the selected phytocompounds 6-Hydroxyondansetron (A104) and Quercitrin (A166) demonstrated that 6-Hydroxyondansetron passes all the required drug discovery rules which can potentially inhibit Mpro and PLpro of SARS-CoV-2 without causing toxicity while Quercitrin demonstrated less drug-like properties but also demonstrated as potential inhibitor for ADRP. Present findings confer opportunities for 6-Hydroxyondansetron and Quercitrin to be developed as new therapeutic drug against COVID-19.

Sodium houttuynia alleviates airway inflammation in asthmatic mice by regulating FoxP3/RORγT expression and reversing Treg/Th17 cell imbalance.

Synthetized from a natural oil of Houttuynia cordata, sodium houttuynia was reported to have anti-inflammatory effects. The present study aimed to investigate whether sodium houttuynia could alleviate the characteristic airway inflammation and Treg/Th17 cell imbalance of asthma in vivo. Experimental mice with neutrophilic asthma were injected with sodium houttuynia or dexamethasone (alone or in combination) intraperitoneally. The airway reactivity was measured, and bronchoalveolar lavage fluid was collected for cell count. Hematoxylin/eosin and periodic acid-Schiff staining were performed to assess pulmonary inflammation and mucus hypersecretion. Immunohistochemical analysis was conducted to determine the expression of IL-10, IL-17A, FoxP3, and RORγT in the lung tissue, and the serum levels of IL-10 and IL-17A were analyzed by ELISA. The proportion of CD4+CD25+FoxP3+ Treg and Th17 cells within the CD4+ T cell subset of splenocytes was analyzed by flow cytometry. FoxP3 and RORγT mRNA and protein expressions in the lung were analyzed by real-time PCR and western blot, respectively. Overall, sodium houttuynia was found to ameliorate the Treg/Th17 cell imbalance and reduce the airway inflammation, hyperresponsiveness, and mucus hypersecretion by increasing the frequency of CD4+CD25+FoxP3+ Treg cells and the secretion of IL-10, while decreasing the proportion of Th17 cells and IL-17A production. Although the regulatory effect of sodium houttuynia was not as good as that achieved with dexamethasone, combination of the two compounds showed improved inhibitory effects on airway hyperresponsiveness, inflammation, and mucus hypersecretion. Hence, sodium houttuynia may be beneficial for the treatment of asthma.

Anti-inflammatory activity of the dietary supplement Houttuynia cordata fermentation product in RAW264.7 cells and Wistar rats.

Houttuynia cordata Thunb. has been used as a traditional medicine to treat a variety of ailments in Asian countries such as China, Japan, South Korea, and Thailand. In Thailand, H. cordata fermentation products (HCFPs) are commercially produced and popularly consumed throughout the country without experimental validation. Anti-inflammatory activity of H. cordata fresh leaves or aerial parts has previously been reported, however, the anti-inflammatory activity of the commercially available HCFPs produced by the industrialized process has not yet been investigated. The aim of this study was to evaluate in vitro and in vivo anti-inflammatory potential of the selected industrialized HCFP. LPS-induced RAW264.7 and carrageenan-induced paw edema models were used to evaluate the anti-inflammatory activity of HCFP. The phenolic acid components of HCFP aqueous and methanolic extracts were investigated using HPLC analysis. In RAW264.7 cells, the HCFP aqueous and methanolic extracts reduced NO production and suppressed LPS-stimulated expression of PGE2, iNOS, IL-1ß, TNF-α and IL-6 levels in a concentration-dependent manner, however, less effect on COX-2 level was observed. In Wistar rats, 3.08 and 6.16 mL/kg HCFP reduced paw edema after 2 h carrageenan stimulation, suggesting the second phase anti-edematous effect similar to diclofenac (150 mg/kg). Whereas, 6.16 mL/kg HCFP also reduced paw edema after 1 h carrageenan stimulation, suggesting the first phase anti-edematous effect. Quantitative HPLC revealed the active phenolic compounds including syringic, vanillic, p-hydroxybenzoic and ferulic acids, which possess anti-inflammatory activity. Our results demonstrated for the first time the anti-inflammatory activity of the industrialized HCFP both in vitro and in vivo, thus validating its promising anti-inflammation potential.

Lactic acid bacteria-fermented product of green tea and Houttuynia cordata leaves exerts anti-adipogenic and anti-obesity effects.

Obesity is associated with higher risks of developing diabetes and cardiovascular disease. Green tea, rich in polyphenolic compounds such as epigallocatechin gallate (EGCG) and epigallocatechin (EGC), has been shown to display anti-obesity effects. Houttuynia cordata leaves have also been shown to exhibit anti-obesity effects due to their chlorogenic acid content. Lactic acid bacteria are able to increase the production of polyphenolic compounds. This study aims to develop a novel anti-obesity fermentation product by combining H. cordata leaf tea with green tea, using Lactobacillus paracasei subsp. paracasei NTU 101 (NTU 101) for fermentation due to the advantages of bioconverting the polyphenolic compounds. The regulation of adipogenesis factors and the anti-obesity effect of the NTU 101-fermented tea were evaluated in an in vitro 3T3-L1 pre-adipocyte model and an in vivo obese rat model, respectively. The results show that the NTU 101-fermented tea, which contained higher EGCG, EGC, and chlorogenic acid levels than unfermented tea, was able to inhibit the lipogenesis of mature 3T3-L1 adipocytes by the stimulation of lipolysis. Furthermore, the body weight gain, body fat pad, and feeding efficiency of obese rats, induced with a high fat diet, were decreased by the oral administration of NTU 101-fermented tea. The significant anti-obesity effect was probably due to lipolysis. However, NTU 101 bacteria cells and EGCG may also act as functional ingredients to contribute to the anti-obesity effects of NTU 101-fermented products.

[Correlation analysis of nutrients and microorganisms in soils with polyphenols and total flavonoids of Houttuynia cordata].

The relationship of nutrients and microorganisms in soils with polyphenols and total flavonoids of Houttuynia cordata were investigated by measuring nutrients, enzyme activity, pH, concentrations of microbe phospholipid fatty acids (PLFAs) in soils, and determining concentrations of polyphenols and total flavonoids of H. cordata. The research is aimed to understand characteristics of the planting soils and improve the quality of cultivated H. cordata. The soils at different sample sites varied greatly in nutrients, enzyme activity, pH, microbic PLFAs and polyphenols and all flavonoids. The content of total PLFAs in sample sites was following: bacteria > fungi > actinomyces > nematode. The content of bacteria PLFAs was 37.5%-65.0% at different sample sites. Activities of polyphenol oxidease, concentrations of available P and content of PLFAs of bacteria, actinomyces and total microorganisms in soils were significantly and positively related to the concentrations of polyphenols and total flavonoids of H. cordata, respectively (P < 0.05) . The Content of fungi PLFAs in soils was significantly and negatively related to concentrations of polyphenols and total flavonoids of H. cordata, respectively (P < 0.05). This study provides evidence that effectiveness of the soil nutrient, which may be improved due to transformation of soil microorganisms and enzymes to N and P in the soils, was beneficial to adaptation of H. cordata adapted to different soil conditions, and significantly affects metabolic accumulation of polyphenols and flavonoids of H. cordata.

Transcriptome analysis of Houttuynia cordata Thunb. by Illumina paired-end RNA sequencing and SSR marker discovery.

BACKGROUND: Houttuynia cordata Thunb. is an important traditional medical herb in China and other Asian countries, with high medicinal and economic value. However, a lack of available genomic information has become a limitation for research on this species. Thus, we carried out high-throughput transcriptomic sequencing of H. cordata to generate an enormous transcriptome sequence dataset for gene discovery and molecular marker development. PRINCIPAL FINDINGS: Illumina paired-end sequencing technology produced over 56 million sequencing reads from H. cordata mRNA. Subsequent de novo assembly yielded 63,954 unigenes, 39,982 (62.52%) and 26,122 (40.84%) of which had significant similarity to proteins in the NCBI nonredundant protein and Swiss-Prot databases (E-value <10(-5)), respectively. Of these annotated unigenes, 30,131 and 15,363 unigenes were assigned to gene ontology categories and clusters of orthologous groups, respectively. In addition, 24,434 (38.21%) unigenes were mapped onto 128 pathways using the KEGG pathway database and 17,964 (44.93%) unigenes showed homology to Vitis vinifera (Vitaceae) genes in BLASTx analysis. Furthermore, 4,800 cDNA SSRs were identified as potential molecular markers. Fifty primer pairs were randomly selected to detect polymorphism among 30 samples of H. cordata; 43 (86%) produced fragments of expected size, suggesting that the unigenes were suitable for specific primer design and of high quality, and the SSR marker could be widely used in marker-assisted selection and molecular breeding of H. cordata in the future. CONCLUSIONS: This is the first application of Illumina paired-end sequencing technology to investigate the whole transcriptome of H. cordata and to assemble RNA-seq reads without a reference genome. These data should help researchers investigating the evolution and biological processes of this species. The SSR markers developed can be used for construction of high-resolution genetic linkage maps and for gene-based association analyses in H. cordata. This work will enable future functional genomic research and research into the distinctive active constituents of this genus.

Protective effects of bone marrow-derived endothelial progenitor cells and Houttuynia cordata in lipopolysaccharide-induced acute lung injury in rats.

BACKGROUND/AIMS: Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is a serious health problem, and an effective treatment is needed for use in the clinical setting. METHODS: In this study, we first constructed ALI models in Adult Sprague-Dawley rats. We then used an herbal medicine, Houttuynia cordata (HC), to enhance the effect of endothelial progenitor cells (EPCs) on ALI. RESULTS: (1) HC improved the therapeutic effects of EPCs on lipopolysachharide-induced ALI in the rat model; (2) HC down-regulated the anti-inflammatory response by suppressing inflammatory cytokines; (3) the combination of EPC and HC reduced expression of iNOS and ET-1 and subsequently prevented lung injury. CONCLUSION: Combined EPC and HC therapy was more effective than either therapy alone. EPC and HC could be used in the clinical treatment of ALI.

Houttuynia cordata Thunb inhibits the production of pro-inflammatory cytokines through inhibition of the NFκB signaling pathway in HMC-1 human mast cells.

Houttuynia cordata Thunb (HCT) is widely used in oriental medicine as a remedy for inflammation. However, at present there is no explanation for the mechanism by which HCT affects the production of inflammatory cytokines. The current study aimed to determine the effect of an essence extracted from HCT on mast cell-mediated inflammatory responses. Inflammatory cytokine production induced by phorbol myristate acetate (PMA) plus a calcium ionophore, A23187, was measured in the human mast cell line, HMC-1, incubated with various concentrations of HCT. TNF-α, IL-6 and IL-8 secreted protein levels were measured using an ELISA assay. TNF-α, IL-6 and IL-8 mRNA levels were measured using RT-PCR analysis. Nuclear and cytoplasmic proteins were examined by western blot analysis. The NF-κB promoter activity was examined by luciferase assay. It was observed that HCT inhibited PMA plus A23187-induced TNF-α and IL-6 secretion and reduced the mRNA levels of TNF-α, IL-6 and IL-8. It was also noted that HCT suppressed the induction of NF-κB activity, inhibited nuclear translocation of NF-κB and blocked the phosphorylation of IκBα in stimulated HMC-1 cells. It was concluded that HCT is an inhibitor of NF-κB and cytokines blocking mast cell-mediated inflammatory responses. These results indicate that HCT may be used for the treatment of mast cell-derived allergic inflammatory diseases.

Orthogonal projection (OP) technique applied to pattern recognition of fingerprints of the herbal medicine houttuynia cordata Thunb. and its final injection products.

It is a crucial issue to determine the origins of herbal medicinal materials and identify the quality grades and fakes of their final products collected from different pharmaceutical corporations. Pattern recognition technique may assist the manufacturers to achieve this purpose and effectively control the quality of their products. In this work, a widely used method in chemometrics, orthogonal projection (OP) technique, was applied to discrimination analysis and identification of fingerprints of the herbal medicine houttuynia cordata Thunb. (HCT) and its final injection products. The advantages of the OP technique are clearly shown after comparing with the conventional methods such as principal component analysis (PCA), Mahalanobis distance (MD), and similarity comparison method (SCM). Three different sources of medicinal material HCT and its final injection products from six different manufacturers were studied under 'sixfold', 'threefold' and 'threefold-bis' cross-validation procedures. The good performance of the proposed method in determination and identification of unknown samples shows it could be a powerful tool for quality control in herbal medicine production and other related research fields.