Anti-bacterial and anti-inflammatory effects of ethanol extract from Houttuynia cordata poultice

Transcriptomics-based anti-tuberculous mechanism of traditional Chinese polyherbal preparation NiuBeiXiaoHe intermediates

Background

Integrated traditional Chinese medicine and biomedicine is an effective method to treat tuberculosis (TB). In our previous research, traditional Chinese medicine preparation NiuBeiXiaoHe (NBXH) achieved obvious anti-TB effects in animal experiments and clinical practice. However, the action mechanism of NBXH has not been elucidated.

Method

Peripheral blood mononuclear cells (PBMCs) were collected to extract mRNA and differentially expressed (DE) genes were obtained using gene microarray technology. Finally, GEO databases and RT-qPCR were used to verify the results of expression profile.

Result

After MTB infection, most upregulated DE genes in mice were immune-related genes, including cxcl9, camp, cfb, c4b, serpina3g, and ngp. Downregulated DE genes included lrrc74b, sult1d1, cxxc4, and grip2. After treatment with NBXH, especially high-dose NBXH, the abnormal gene expression was significantly corrected. Some DE genes have been confirmed in multiple GEO datasets or in pulmonary TB patients through RT-qPCR.

Conclusion

MTB infection led to extensive changes in host gene expression and mainly caused the host's anti-TB immune responses. The treatment using high-dose NBXH partially repaired the abnormal gene expression, further enhanced the anti-TB immunity included autophagy and NK cell-mediated cytotoxicity, and had a certain inhibitory effect on overactivated immune responses.

Unraveling the treasure trove of phytochemicals in mitigating the Salmonella enterica infection

Foodborne diseases triggered by various infectious micro-organisms are contributing significantly to the global disease burden as well as to increasing mortality rates. Salmonella enterica belongs to the most prevalent form of bacteria accountable for significant burden of foodborne illness across the globe. The conventional therapeutic approach to cater to Salmonella enterica-based infections relies on antibiotic therapy, but the rapid emergence of the antibiotic resistance strains of Salmonella sp. necessitates the development of alternative treatment and prevention strategies. In light of this growing concern, the scientific community is rigorously exploring novel phytochemicals harnessed from medicinally important plants as a promising approach to curb Salmonella enterica infections. A variety of phytochemicals belonging to alkaloids, phenols, flavonoid, and terpene classes are reported to exhibit their inhibitory activity against bacterial cell communication, membrane proteins, efflux pumps, and biofilm formation among drug resistant Salmonella strains. The present review article delves to discuss the emergence of antibiotic resistance among Salmonella enterica strains, various plant sources, identification of phytochemicals, and the current state of research on the use of phytochemicals as antimicrobial agents against Salmonella enterica, shedding light on the promising potential of phytochemicals in the fight against this pathogen.

Evaluating the Efficacy of Hymexazol in Controlling Globisporangium spinosum, the Newly Identified Pathogen Causing Root Rot in Houttuynia cordata

Houttuynia cordata is a prevalent vegetable in several Asian countries and is commonly used as a traditional Chinese medicinal herb for treating various diseases in China. Unfortunately, its yield and quality are adversely affected by root rot. However, the pathogen responsible for the losses remains unidentified, and effective fungicides for its management have not been thoroughly explored. In this work, we demonstrate the first report of Globisporangium spinosum as the causative agent causing root rot of H. cordata. Moreover, we evaluated the efficacy of hymexazol to manage the disease, which displayed remarkable inhibitory effects against mycelial growth of G. spinosum in vitro, with EC50 values as low as 1.336 μg/ml. Furthermore, hymexazol completely inhibited sporangia in G. spinosum at a concentration of 0.3125 μg/ml. Specifically, we observed that hymexazol was highly efficacious in reducing the incidence of H. cordata root rot caused by G. spinosum in a greenhouse setting. These findings offer a potential management tool for utilization of hymexazol in controlling H. cordata root rot in field production.

Houttuynia Cordata Thunb.: A comprehensive review of traditional applications, phytochemistry, pharmacology and safety

BACKGROUND

Houttuynia Cordata Thunb. (H. cordata; Saururaceae) is a medicine food homology plant that is grown in many Asian countries. Its main phytochemical constituents are volatile oils, flavonoids, polysaccharides and alkaloids. It has considerable clinical applications and health benefits.

PURPOSE

This paper reviews the existing literatures and patents, summarizes the phytochemistry, pharmacological activity, safety and economic botanical applications of H. cordata, and provides a reference for systematic study of the pharmacological effects of H. cordata, improvement of quality standards and further development of its medicinal resources.

METHODS

A comprehensive search of literature and patents on H. cordata and its active ingredients published before June 2023 was conducted using PubMed, Google Scholar, Web of Science, and China Knowledge Network.

RESULTS

H. cordata is not only edible and medicinal but also used in various aspects of daily life such as fermented beverages, nutraceuticals, feed and cosmetics. The main phytochemical constituents of H. cordata are volatile oils, flavonoids, organic acids and alkaloids. Several in vitro and in vivo studies and clinical trials have found that H. cordata extracts possess antioxidant, anti-inflammatory, antitumor, antibacterial, hepatoprotective and renal, immunomodulatory and potent antiviral effects. The mechanisms of expression of these pharmacological effects are related to the blood-brain barrier, lipophilicity, cAMP signaling and skin permeability, including blocking the MAPK signaling pathway, inhibiting the secretion of inflammatory factors such as TNF-α and IL-1β, and activating the AMPK pathway.

CONCLUSION

This paper provides a comprehensive review of the progress of research on the traditional applications, botany, chemical composition, pharmacological effects and safety of H. cordata and discusses for the first time the economic botanical aspects, which were not explored in the previous reviews. H. cordata has a wide range of bioactive substances whose therapeutic potential has not been fully exploited, and it could provide a new non-toxic approach to many diseases. This traditional medicinal food plant should receive more attention and in-depth research in the future.

Bacteriocin-Producing Enterococcus faecium OV3-6 as a Bio-Preservative Agent to Produce Fermented Houttuynia cordata Thunb. Beverages: A Preliminary Study

Microbial contamination affects the quality of the fermented Houttuynia cordata Thunb. (H. cordata) beverage (FHB). The present study aimed to assess the bio-preservative property of Enterococcus faecium OV3-6 (E. faecium OV3-6) during the production of FHB. The antimicrobial activity against Escherichia coli, Salmonella, Bacillus cereus, and Staphylococcus aureus and the survival of E. faecium OV3-6 were studied. Then, FHB fermentation was performed with different preservatives (non-preservative, E. faecium OV3-6, cell-free supernatant of E. faecium OV3-6, and nisin) with and without representative pathogens. The maximum antimicrobial activity against S. aureus and B. cereus was observed after 18 h of cultivation in an MRS medium. E. faecium OV3-6 was used as a starter to produce the FHB, and the strain survived up to 48 h in the fermented beverage. E. faecium OV3-6 and its cell-free supernatant inhibited the growth of E. coli, Salmonella, B. cereus, and S. aureus in the stimulated FHB. The non-preservatives and nisin-containing FHB showed inhibition against Gram-positive pathogens. The FHB treated with E. faecium OV3-6 was rich in lactic acid bacteria, and the product was at an acceptable level of pH (less than 4.3). Certain limitations were identified in the study, such as lack of nutritional, metabolomics analysis, and safety and consumer acceptability of FHB. The results suggested that E. faecium OV3-6 could be used as a bio-preservative to produce fermented plant beverages (FPBs).

RP-HPLC-Based Flavonoid Profiling Accompanied with Multivariate Analysis: An Efficient Approach for Quality Assessment of Houttuynia cordata Thunb Leaves and Their Commercial Products

Chemical profiling for quality monitoring and evaluation of medicinal plants is gaining attention. This study aims to develop an HPLC method followed by multivariate analysis to obtain HPLC profiles of five specific flavonoids, including rutin (1), hyperin (2), isoquercitrin (3), quercitrin (4), and quercetin (5) from Houttuynia cordata leaves and powder products and assess the quality of H. cordata samples. Eventually, we successfully established HPLC-based flavonoid profiles and quantified the contents of 32 H. cordata fresh leave samples and four powder products. The study also quantified the contents of those five essential flavonoids using an optimized RP-HPLC method. Peak areas of samples were then investigated with principal component analysis (PCA) and hierarchical cluster analysis (HCA) to evaluate the similarity and variance. Principal components in PCA strongly influenced by hyperin and quercetin showed that the samples were clustered into subgroups, demonstrating H. cordata samples' quality. The results of HCA showed the similarity and divided the samples into seven subgroups. In conclusion, we have successfully developed a practical methodology that combined the HPLC-based flavonoid profiling and multivariate analysis for the quantification and quality control of H. cordata samples from fresh leaves and powder products. For further studies, we will consider various environmental factors, including climate and soil factors, to investigate their effects on the flavonoid contents of H. cordata.

Anti-Aging, Anti-Acne, and Cytotoxic Activities of Houttuynia cordata Extracts and Phytochemicals Analysis by LC-MS/MS

Although many biological properties of Houttuynia cordata have been found, its anti-aging and anti-acne effects have not yet been investigated. This study was aimed to evaluate the in vitro anti-aging and anti-acne activities of H. cordata extracts and their cytotoxic activities and phytochemicals analyzed with liquid chromatography with tandem mass spectrometry (LC-MS/MS). Dried aerial parts of H. cordata were given different extractions. The aqueous and ethanolic extracts obtained were named HCA and HCE, respectively, and used to screen total phenolic and flavonoid contents. In vitro anti-aging, skin-related antimicrobial, scanning electron microscopy (SEM), in vitro cytotoxic, and LC-MS/MS analyses were performed. The total phenolic contents of the HCA and HCE were 5.11 ± 0.25 and 27.02 ± 1.07 mg gallic acid equivalent (GAE)/g dry extract while their total flavonoid contents were 104.94 ± 5.16 and 571.86 ± 2.86 mg quercetin equivalent (QE)/g dry extract, respectively. The HCA and HCE inhibited the activities of collagenase (28.33–46.00%), elastase (30.00–34.33%), and hyaluronidase (93.87–98.72%). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the HCA against Cutibacterium acnes DMST14916 were 5.77 and 5.77 mg/mL while those of the HCE were 2.47 and 2.47 mg/mL, respectively. Cell collapses of C. acnes after treatment with the extracts were observed with SEM. The HCE was not toxic to macrophages, keratinocytes, and fibroblasts up to 400 mg/mL. The HCA showed toxicity against macrophages at 62.5 mg/mL and both skin cells at 250 mg/mL. The main phytochemicals in the extracts were identified with LC-MS/MS. Phenolic compounds, flavonoids, and flavonoid derivatives in H. cordata extracts could be major phytochemicals to possess a broad spectrum of biological activities including antioxidant, antimicrobial, and anti-aging activities. The findings from this study showed that the HCE has potential anti-aging and anti-acne properties while having non-cytotoxic activities on the immune and skin cells. These results indicate that the extract is probably advantageous in the development of skincare cosmeceutics and beauty treatments.

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.

Antimicrobial activities and mechanisms of extract and components of herbs in East Asia

Antibacterial drugs face increasing challenges due to drug resistance and adverse reactions, which has created a pressing need for the discovery and development of novel antibacterial drugs. Herbs have played an important role in the treatment of infectious diseases. This review aims to summarize, analyze and evaluate the antibacterial activities and mechanisms of components from popular herbs in East Asia. In this review, we have searched and summarized the scientific papers published during the past twenty-year period from electronic databases such as PubMed, ScienceDirect, and Web of Science. These herbs and their components, including alkaloids, flavonoids, essential oils, terpenes, organic acids, coumarins and lignans, display potential antimicrobial effects. Herbal medicine formulas (HMFs) usually show stronger antibacterial activity than single herbs. Herbs and HMFs bring forth antibacterial activities by damaging cell membranes and walls, inhibiting nucleic acid and protein synthesis, and increasing intracellular osmotic pressure. These herbs and their components can be developed as potential and promising novel antibacterial herbal products.

Pharmacological Effects of Houttuynia cordata Thunb (H. cordata): A Comprehensive Review

Houttuynia cordata Thunb (H. cordata) is a rhizomatous, herbaceous, and perennial plant widely distributed in Asia. It has multiple chemical constituents, such as alkaloids, essential oils, phenolic acids, and flavonoids used against various health problems. The essential oils and flavonoids are the main components of H. cordata that play an essential role in disease treatment and traditional health care. Moreover, the leaves and stems of H. cordata have a long medicinal history in China. In addition, H. cordata is used against several health issues, such as cold, cough, fever, pneumonia, mumps, and tumors, due to its anti-inflammatory, anti-bacterial, anti-viral, anti-oxidant, and anti-tumor effects. It protects organs due to its anti-inflammatory activity. H. cordata regulates immunity by enhancing immune barriers of the oral cavity, vagina, and gastrointestinal tract, and shows broad-spectrum activity against liver, lung, breast, and colon tumors. However, there are some gaps to be filled to understand its pathways and mechanisms. Mechanisms such as its interaction with cells, cell membranes, and various drugs are important. Studies in relation to the blood–brain barrier, lipophilicity, cAMP signaling, and skin permeability, including pharmaceutical effects, will be very useful. This review includes the biological and pharmacological activities of H. cordata based on up-to-date research.

Preparation of an eco-friendly antibacterial agent for food packaging containing Houttuynia cordata Thunb. extract

This study aims to develop an antibacterial agent that can be used for food packaging. Essential oils of Houttuynia cordata Thunb., a well-known medical herb, were extracted by two methods: multi-solvent consecutive extraction method and single ethanol extraction with a pre-heating method. Consequently, the extract obtained by the single ethanol extraction with a pre-heating method was more satisfactory from the operational and economic aspects. Afterwards, one of the encapsulation techniques: co-precipitation method using β-cyclodextrins as wall materials, was applied to form capsules for the protection of the obtained extract. After the capsule synthesis, the results of scanning electron micrographs and X-ray diffraction showed β-cyclodextrin crystallites in the form of thinner plates became oriented upon co-precipitation. Combining the results of Fourier transform-infrared spectra and an antibacterial assay using Bacillus subtilis as an object microorganism, the extract was confirmed to be successfully encapsulated within hollow cavities of β-cyclodextrins. A significant inhibitory activity on the growth and breeding of Bacillus subtilis was observed after the addition of fabricated capsules, which suggests the capsules containing the Houttuynia cordata Thunb. extract can be used as eco-friendly antibacterial agents for food packaging.

Houttuynia cordata Thunb: An Ethnopharmacological Review

Houttuynia cordata Thunb (H. cordata; Saururaceae) is widely distributed in Asian regions. It plays an important role in traditional health care and disease treatment, as its aboveground stems and leaves have a long medicinal history in China and are used in the treatment of pneumonia and lung abscess. In clinical treatment, it can usually be combined with other drugs to treat dysentery, cold, fever, and mumps; additionally, H. cordata is an edible plant. This review summarizes detailed information on the phytochemistry and pharmacological effects of H. cordata. By searching the keywords “H. cordata and lung”, “H. cordata and heart”, “H. cordata and liver”, and “H. cordata and inflammation” in PubMed, Web of Science and ScienceDirect, we screened out articles with high correlation in the past ten years, sorted out the research contents, disease models and research methods of the articles, and provided a new perspective on the therapeutic effects of H. cordata. A variety of its chemical constituents are characteristic of medicinal plants, the chemical constituents were isolated from H. cordata, including volatile oils, alkaloids, flavonoids, and phenolic acids. Flavonoids and volatile oils are the main active components. In pharmacological studies, H. cordata showed organ protective activity, such as reducing the release of inflammatory factors to alleviate lung injury. Moreover, H. cordata regulates immunity, enhances the immune barriers of the vagina, oral cavity, and intestinal tract, and combined with the antibacterial and antiviral activity of its extract, effectively reduces pathogen infection. Furthermore, experiments in vivo and in vitro showed significant anti-inflammatory activity, and its chemical derivatives exert potential therapeutic activity against rheumatoid arthritis. Antitumour action is also an important pharmacological activity of H. cordata, and studies have shown that H. cordata has a notable effect on lung tumour, liver tumour, colon tumour, and breast tumour. This review categorizes the biological activities of H. cordata according to modern research papers, and provides insights into disease prevention and treatment of H. cordata.

Phytochemicals: A Promising Weapon in the Arsenal against Antibiotic-Resistant Bacteria

The extensive usage of antibiotics and the rapid emergence of antimicrobial-resistant microbes (AMR) are becoming important global public health issues. Many solutions to these problems have been proposed, including developing alternative compounds with antimicrobial activities, managing existing antimicrobials, and rapidly detecting AMR pathogens. Among all of them, employing alternative compounds such as phytochemicals alone or in combination with other antibacterial agents appears to be both an effective and safe strategy for battling against these pathogens. The present review summarizes the scientific evidence on the biochemical, pharmacological, and clinical aspects of phytochemicals used to treat microbial pathogenesis. A wide range of commercial products are currently available on the market. Their well-documented clinical efficacy suggests that phytomedicines are valuable sources of new types of antimicrobial agents for future use. Innovative approaches and methodologies for identifying plant-derived products effective against AMR are also proposed in this review.

Efficacy and Safety of Houttuynia Eye Drops Atomization Treatment for Meibomian Gland Dysfunction-Related Dry Eye Disease: A Randomized, Double-Blinded, Placebo-Controlled Clinical Trial

Purpose: To evaluate the efficacy and safety of Houttuynia eye drops (a Chinese traditional medicine) atomization treatment in meibomian gland dysfunction (MGD)-related dry eye disease (DED) patients. Methods: A total of 240 eligible patients diagnosed with MGD-related DED were assigned either Houttuynia eye drops or placebo for atomization once daily for four weeks in a multi-center, randomized, double-blind, placebo-controlled clinical study. Primary outcome evaluations used included eye symptom score (using the Chinese Dry Eye Questionnaire), meibum quality, and tear break-up time (TBUT), while safety evaluations included adverse events (AEs), visual acuity, and intraocular pressure monitoring. Indicators were measured at baseline as well as one week, two weeks, and four weeks after treatment. Results: Primary outcome measures of the Houttuynia group were improved compared with their placebo counterparts following four-week treatment. Eye symptom scores were significantly reduced relative to the baseline in the Houttuynia group (mean ± standard error of the mean, 9.00 ± 0.61) compared with the placebo group (6.29 ± 0.55; p = 0.0018). Reduction in meibum quality score in the Houttuynia group (0.91 ± 0.10) was also significantly higher compared with the placebo group (0.57 ± 0.10; p = 0.0091), while TBUT in the treatment group (6.30 ± 0.22) was also longer than in the latter (5.60 ± 0.24; p = 0.0192). No medication-related adverse events were observed. Conclusions: Atomization treatment with Houttuynia eye drops is both clinically and statistically effective for the treatment of mild to moderate MGD-related DED patients. This approach is generally safe and was tolerated well by patients.

Identifying the Chinese Herbal Medicine Network and Core Formula for Allergic Rhinitis on a Real-World Database

MATERIALS AND METHODS

Patients with a primary diagnosis of AR (ICD-9-CM code: 477.9) in 2010 were included, and the National Health Insurance Research Database in Taiwan was used as the data source. Association rule mining and social network analysis were used to establish and explore the CHM network. Possible molecular pathways of the CHM network were summarized and compared with commonly used western medicine (WM) by conducting overrepresentation analysis in the Reactome pathway database. The potential proteins acted by CHMs were obtained from the CHM ingredient-protein databases, including STITCH, TCMSP, TCMID, and TCM@Taiwan.

RESULTS

There were 89,148 AR subjects found in 2010, and a total of 33,507 patients ever used CHM. On an average, 5.6 types of CHMs were utilized per prescription. Xin-Yi-Qing-Fei-Tang was used most frequently (25.5% of 222,279 prescriptions), while Xiao-Qing-Long-Tang with Xin-Yi-San was the most commonly prescribed CHM-CHM combination. Up to six distinctive clusters could be found among the CHM network, and core CHMs could be found for AR, such as Xiao-Qing-Long-Tang and Xin-Yi-Qing-Fei-Tang. A total of 140 molecular pathways were covered by the CHM network (2,432 ingredients from 31 kinds of CHMs), while 39 WMs covered 55 pathways. Among pathways responding to the immune system, WM mainly acted on cytokine signaling-related pathways, while CHM mostly acted on neutrophil/macrophage-related innate pathways and dendritic cell-related adaptive immunity pathways.

CONCLUSION

Our study demonstrated and analyzed the CHM network for AR. Core CHM for AR and possible molecular pathways were presented as well, and this information is crucial for researchers to select candidates for CHM-related studies.

Hair Growth Promoting Effect of Hottuynia cordata Extract in Cultured Human Hair Follicle Dermal Papilla Cells

Houttuynia cordata (HC) is a traditional oriental herbal medicinal plant widely used as a component of complex prescriptions in Asia for alopecia treatment. The effect of HC on hair growth and its underlying mechanism, however, have not been demonstrated or clarified. In this study, we investigated the hair growth promoting effect of HC in cultured human dermal papilla cells (hDPCs). HC extract was found to stimulate the proliferation of hDPCs and this stimulation might be in part a consequence of activated cellular energy metabolism, because treatment of HC extract increased the generation of nicotinamide adenine dinucleotide (NADH) and ATP through increasing the mitochondrial membrane potential (ΔΨ). In the context of cell cycle, HC extract increased the expression of CDK4 and decreased the expression of CCNA2 and CCNB1, implying that HC extract might induce G1 phase progression of DPCs which resulted in enhanced proliferation. HC extract increased the expression of Bcl2 essential for maintaining hair follicle anagen stage and cell survival. On the contrary, the expression of p16 and p21 was down-regulated by HC extract. In addition, HC extract enhanced the secretion of platelet-derived growth factor (PDGF)-aa and vascular endothelial growth factor (VEGF) and induced phosphorylation of extracellular signal-regulated kinase (ERK) and AKT. Furthermore, HC extract prolonged anagen stage in organ cultured human hair follicles. Our data strongly suggest that HC extract could support hair growth by stimulating proliferation of DPCs and elongating anagen stage, resulted from enhanced cellular energy metabolism and modulation of gene expression related to cell cycle, apoptosis, and growth factors.

Houttuynia cordata polysaccharide alleviated intestinal injury and modulated intestinal microbiota in H1N1 virus infected mice

Houttuynia cordata polysaccharide (HCP) is extracted from Houttuynia cordata, a key traditional Chinese medicine. The study was to investigate the effects of HCP on intestinal barrier and microbiota in H1N1 virus infected mice. Mice were infected with H1N1 virus and orally administrated HCP at a dosage of 40 mg(kg⁻¹(d⁻¹. H1N1 infection caused pulmonary and intestinal injury and gut microbiota imbalance. HCP significantly suppressed the expression of hypoxia inducible factor-1α and decreased mucosubstances in goblet cells, but restored the level of zonula occludens-1 in intestine. HCP also reversed the composition change of intestinal microbiota caused by H1N1 infection, with significantly reduced relative abundances of Vibrio and Bacillus, the pathogenic bacterial genera. Furthermore, HCP rebalanced the gut microbiota and restored the intestinal homeostasis to some degree. The inhibition of inflammation was associated with the reduced level of Toll-like receptors and interleukin-1β in intestine, as well as the increased production of interleukin-10. Oral administration of HCP alleviated lung injury and intestinal dysfunction caused by H1N1 infection. HCP may gain systemic treatment by local acting on intestine and microbiota. This study proved the high-value application of HCP.

Efficacy of Houttuynia eye drops for the treatment of vernal keratoconjunctivitis: A systemic review and meta-analysis protocol

BACKGROUND

Vernal keratoconjunctivitis (VKC) is a common eye disease and can result in permanent decrease or loss of vision. Houttuynia eye drops (HED) is used for the treatment of VKC. However, the clinical evidence of HED has not been well concluded. Herein, we described a proposed systemic review and meta-analysis to evaluate the clinical efficacy of HED for the treatment of VKC.

METHODS

Six electronic databases (Medline, Embase, the Cochrane database, Chinese National Knowledge Infrastructure, Wanfang database, and Chinese Biology and Medicine database) will be searched for randomized controlled trials (RCTs) which evaluating the clinical efficacy of HED for the treatment of VKC. Studies meet the eligibility criteria will be included. Data of the included studies will be extracted and the quality will also be evaluated. Data synthesis will be performed using RevMan software. Sensitivity analysis and publication bias will also be investigated.

RESULTS

This study will provide high-quality systemic review and synthesis of RCTs on efficacy of HED for the treatment of VKC.

CONCLUSION

This systemic review and meta-analysis will conclude the efficacy of HED for the treatment of VKC.

REGISTRATION

PROSPERO CRD42019124737.

Antiviral Effects of Houttuynia cordata Polysaccharide Extract on Murine Norovirus-1 (MNV-1)-A Human Norovirus Surrogate

Houttuynia cordata is an herbal plant rich in polysaccharides and with several pharmacological activities. Human noroviruses (HuNoVs) are the most common cause of foodborne viral gastroenteritis throughout the world. In this study, H. cordata polysaccharide (HP), with a molecular weight of ~43 kDa, was purified from H. cordata water extract (HWE). The polysaccharide HP was composed predominantly of galacturonic acid, galactose, glucose, and xylose in a molar ratio of 1.56:1.49:1.26:1.11. Methylation and NMR analyses revealed that HP was a pectin-like acidic polysaccharide mainly consisting of α-1,4-linked GalpA, β-1,4-linked Galp, β-1,4-linked Glcp, and β-1,4-linked Xylp residues. To evaluate the antiviral activity of H. cordata extracts, we compared the anti-norovirus potential of HP with HWE and ethanol extract (HEE) from H. cordata by plaque assay (plaque forming units (PFU)/mL) for murine norovirus-1 (MNV-1), a surrogate of HuNoVs. Viruses at high (8.09 log10 PFU/mL) or low (4.38 log10 PFU/mL) counts were mixed with 100, 250, and 500 μg/mL of HP, HWE or HEE and incubated for 30 min at room temperature. H. cordata polysaccharide (HP) was more effective than HEE in reducing MNV-1 plaque formation, but less effective than HWE. When MNV-1 was treated with 500 μg/mL HP, the infectivity of MNV-1 decreased to an undetectable level. The selectivity indexes of each sample were 1.95 for HEE, 5.74 for HP, and 16.14 for HWE. The results of decimal reduction time and transmission electron microscopic revealed that HP has anti-viral effects by deforming and inflating virus particles, thereby inhibiting the penetration of viruses in target cells. These findings suggest that HP might have potential as an antiviral agent in the treatment of viral diseases.

Organic Houttuynia cordata Thunb harbors higher abundance and diversity of antibiotic resistance genes than non-organic origin, suggesting a potential food safe risk

The organic agricultural products has been growing rapidly in recent years. However, a potential food safe risk, resulted by introduction more antibiotic resistant genes (ARGs) accompanied with animal manure using to organic farming, has long been overlooked. In current study, the bacterial community, 22 tetracycline, 3 aminoglycoside and 4 β-lactams ARGs were respectively investigated in the organic, chemical and wild Houttuynia cordata Thunb (HCT). A total of 9 tetracycline, 3 aminoglycoside and 2 β-lactam ARG subtypes were detected, and the organic HCT harbored more ARG subtypes. The absolute and relative abundance of total ARGs in organic HCT was strikingly higher than that in chemical and wild HCT. The Enterobacteriaceae, Aeromonadaceae, Pseudomonadceae, Moraxellaceae and Oxalobacteraceae were the dominant taxa in the chemical and wild HCT, but in the organic HCT, only Enterobacteriaceae posed 83.23% - 87.40% of bacterial community. Fourteen bacterial families might be the possible hosts of ARG subtypes in the HCT. Enterobacteriaceae was a possible host of most ARG subtypes, including tetA, tetB, tetC, tetE and aadA, and it was the main bacteria affecting the behavior of ARGs in the HCT. Additionally, the tetracycline ARG subtypes had more possible hosts. These results help to better understand the ARG potential food safe risk and develop effective measures to prevent the ARG dissemination in organic agricultural product.

Therapeutic potentials of Houttuynia cordata Thunb. against inflammation and oxidative stress: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Houttuynia cordata Thunb. (Family: Saururaceae) is an herbaceous perennial plant that grows in moist and shady places. The plant is well known among the people of diverse cultures across Japan, Korea, China and North-East India for its medicinal properties. Traditionally the plant is used for its various beneficial properties against inflammation, pneumonia, severe acute respiratory syndrome, muscular sprain, stomach ulcer etc. Oxidative stress and inflammation were found to be linked with most of the diseases in recent times. Many ancient texts from Chinese Traditional Medicine, Ayurveda and Siddha, and Japanese Traditional medicine have documented the efficacy of H. cordata against oxidative stress and inflammation.

AIM OF THE STUDY

This review aims to provide up-to-date and comprehensive information on the efficacy of H. cordata extracts as well as its bioactive compounds both in vitro and in vivo, against oxidative stress and inflammation MATERIALS AND METHODS: Relevant information on H. cordata against oxidative stress and inflammation were collected from the established scientific databases such as NCBI, Web of Science, ScienceDirect, Elsevier, and Springer. Additionally, a few books and magazines were also consulted to get the important information.

RESULTS

Herbal medicines or plant products were traditionally being used for treating the oxidative stress and inflammation related diseases in diverse communities across the world. Scientifically, H. cordata has shown to target several signaling pathways and found to effectively reduce the oxidative stress and inflammation. Phyto-constituents such as afzelin, hyperoside and quercitrin have shown to reduce inflammation both in vitro and in vivo models. These molecules were also shown to have strong antioxidant properties both in vivo and in vitro models.

CONCLUSIONS

H. cordata extracts and its bioactive molecules were shown to have both anti-inflammatory and anti-oxidative properties. As both in vitro and in vivo studies were shown that H. cordata did not have any toxicity on the various model systems used, future clinical studies will hopefully make an impact on the future direction of treating inflammation-related diseases.

Understanding cancer and its treatment in Thai traditional medicine: An ethnopharmacological-anthropological investigation

ETHNOPHARMACOLOGICAL RELEVANCE

Thai traditional medicine (TTM) is widely practiced in Thailand and continues to gain importance in cancer management, but little is known about the TTM practitioners' emic concepts and practice.

AIM OF THE STUDY

With this study we firstly aim to document the practice of cancer treatment and prevention by TTM practitioners and, secondly, to evaluate how such traditional concepts and practices are correlated with biomedical ones. This in turn can form the basis for developing novel strategies for designing pharmacological experiments and longer term strategies to develop TTM practice.

METHODS

Semi-structured interviews with 33 TTM practitioners were performed in five provinces in different regions of Thailand. The following information were recorded; basic information of informants, descriptions of cancer (mareng in Thai), causes, diagnosis, treatment, and prevention. Plants used in the treatment and prevention of mareng were also collected.

RESULTS

Using an in depth ethnographic approach four representative case studies to assist in a better understanding of the characteristics of mareng, its diagnosis, treatment, and prevention are reported here. Five characteristics of mareng - waste accumulation (khong sia), chronic illnesses (krasai), inflammation (kan aksep), bad blood (luead) and lymph (namlueang), and the imbalance of four basic elements (dhātu si) - have been identified. Explanatory models of cancer in TTM were linked with biomedical concepts and relevant pharmacological actions. Traditional uses and available scientific evidence of medicinal plants mentioned in the case studies for the treatment or prevention of mareng are presented and discussed.

CONCLUSION

Here for the first time five main characteristics of cancer based on Thai traditional medical concepts are analysed. Our findings are relevant not only for the planning of clinical studies or pharmacological experiment in the search for novel compounds for cancer treatment and prevention, but also for the integration of Thai traditional medicine in cancer care.

Pharmaceutical Impact of Houttuynia Cordata and Metformin Combination on High-Fat-Diet-Induced Metabolic Disorders: Link to Intestinal Microbiota and Metabolic Endotoxemia

Purpose: Metformin and Houttuynia cordata are representative anti-diabetic therapeutic agents in western and oriental medicinal fields, respectively. The present study examined the therapeutic effects of houttuynia cordata extract (HCE) and metformin in combination in a dysmetabolic mouse model. Methods: Metabolic disorders were induced in C57BL/6J mice by high fat diet (HFD) for 14 weeks. Results: Combination of metformin and HCE significantly lowered body weight, abdominal fat, perirenal fat, liver and kidney weights, but did not change epididymal fat in HFD-fed animals. Metformin + HCE treatment markedly attenuated the elevated serum levels of TG, TC, AST, ALT, and endotoxin and restored the depleted HDL level. Both HCE and metformin + HCE treatment ameliorated glucose tolerance and high level of fasting blood glucose in association with AMPK activation. Moreover, treatment with HCE + metformin dramatically suppressed inflammation in HFD-fed animals via inhibition of proinflammatory cytokines (MCP-1 and IL-6) and LPS receptor (TLR4). Histopathological findings showed that exposure of HFD-treated animals to metformin + HCE ameliorated fatty liver, shrinkage of intestinal villi and adipocytes enlargement. Furthermore, HCE and metformin + HCE treatments markedly modulated the abundance of gut Gram-negative bacteria, including Escherichia coli and Bacteriodetes fragilis, but not universal Gram-positive bacteria. Conclusions: Overall, HCE and metformin cooperatively exert their therapeutic effects via modulation of gut microbiota, especially reduction of Gram-negative bacteria, resulting in alleviation of endotoxemia.

Development of Houttuynia cordata Extract-Loaded Solid Lipid Nanoparticles for Oral Delivery: High Drug Loading Efficiency and Controlled Release

Houttuynia cordata (H. cordata) has been used for diuresis and detoxification in folk medicine as well as a herbal medicine with antiviral and antibacterial activities. H. cordata extract-loaded solid lipid nanoparticles (H-SLNs) were prepared with various concentration of poloxamer 188 or poloxamer 407 by a hot homogenization and ultrasonication method. H-SLNs dispersion was freeze-dried with or without trehalose as a cryoprotectant. The physicochemical characteristics of H-SLNs were evaluated by dynamic laser scattering (DLS), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). Additionally, the in vitro release and in vitro cytotoxicity of H-SLNs were measured. Encapsulation efficiencies of H-SLNs (as quercitrin) were 92.9–95.9%. The SEM images of H-SLNs showed that H-SLNs have a spherical morphology. DSC and FT-IR showed that there were no interactions between ingredients. The increased extent of particle size of freeze-dried H-SLNs with trehalose was significantly lower than that of H-SLNs without trehalose. H-SLNs provided sustained release of quercitrin from H. cordata extracts. Cell viability of Caco-2 cells was over 70% according to the concentration of various formulation. Therefore, it was suggested that SLNs could be good carrier for administering H. cordata extracts.

Antibiofilm and Anti-Inflammatory Activities of Houttuynia cordata Decoction for Oral Care

Dental biofilms that form in the oral cavity play a critical role in the pathogenesis of several infectious oral diseases, including dental caries, periodontal disease, and oral candidiasis. Houttuynia cordata (HC, Saururaceae) is a widely used traditional medicine, for both internal and external application. A decoction of dried HC leaves (dHC) has long been consumed as a health-promoting herbal tea in Japan. We have recently reported that a water solution of HC poultice ethanol extract (wHCP) exerts antimicrobial and antibiofilm effects against several important oral pathogens. It also exhibits anti-inflammatory effects on human keratinocytes. In our current study, we examined the effects of dHC on infectious oral pathogens and inflammation. Our results demonstrated that dHC exerts moderate antimicrobial effects against methicillin-resistant Staphylococcus aureus (MRSA) and other oral microorganisms. dHC also exhibited antibiofilm effects against MRSA, Fusobacterium nucleatum (involved in dental plaque formation), and Candida albicans and inhibitory effects on interleukin-8, CCL20, IP-10, and GROα productions by human oral keratinocytes stimulated by Porphyromonas gingivalis lipopolysaccharide (a cause of periodontal disease), without cytotoxic effects. This suggests that dHC exhibits multiple activities in microorganisms and host cells. dHC can be easily prepared and may be effective in preventing infectious oral diseases.

Chemical Composition and Allelopathic, Antibacterial, Antifungal, and Antiacetylcholinesterase Activity of Fish-mint (Houttuynia cordataThunb.) from India

Fish-mint (Houttuynia cordataThunb.), belonging to family Saururaceae, has long been used as food and traditional herbal medicine. The present study was framed to assess the changes occurring in the essential-oil composition of H. cordata during annual growth and to evaluate allelopathic, antibacterial, antifungal, and antiacetylcholinesterase activities. The essential-oil content ranged from 0.06 - 0.14% and 0.08 - 0.16% in aerial parts and underground stem, respectively. The essential oils were analysed by GC-FID, GC/MS, and NMR (¹ H and ¹³ C). Major constituents of aerial-parts oil was 2-undecanone (19.4 - 56.3%), myrcene (2.6 - 44.3%), ethyl decanoate (0.0 - 10.6%), ethyl dodecanoate (1.1 - 8.6%), 2-tridecanone (0.5 - 8.3%), and decanal (1.1 - 6.9%). However, major constituents of underground-stem oil were 2-undecanone (29.5 - 42.3%), myrcene (14.4 - 20.8%), sabinene (6.0 - 11.1%), 2-tridecanone (1.8 - 10.5%), β-pinene (5.3 - 10.0%), and ethyl dodecanoate (0.8 - 7.3%). Cluster analysis revealed that essential-oil composition varied substantially due to the plant parts and season of collection. The oils exhibited significant allelopathic (inhibition: 77.8 - 88.8%; LD₅₀ : 2.45 - 3.05 μl/plate), antibacterial (MIC: 0.52 - 2.08 μl/ml; MBC: bacteriostatic) and antifungal (MIC: 2.08 - 33.33 μl/ml; MFC: 4.16 - 33.33 μl/ml) activities. The results indicate that the essential oil from H. cordata has a significant potential to allow future exploration and exploitation as a natural antimicrobial and allelopathic agent.

Phytotherapy as an alternative to conventional antimicrobials: combating microbial resistance

INTRODUCTION

In the modern antimicrobial era, the rapid spread of resistance to antibiotics and introduction of new and mutating viruses is a global concern. Combating antimicrobial resistant microbes (AMR) requires coordinated international efforts that incorporate new conventional antibiotic development as well as development of alternative drugs with antimicrobial activity, management of existing antimicrobials, and rapid detection of AMR pathogens. Areas covered: This manuscript discusses some conventional strategies to control microbial resistance. The main purpose of the manuscript is to present information on specific herbal medicines that may serve as good treatment alternatives to conventional antimicrobials for infections sensitive to conventional as well as resistant strains of microorganisms. Expert commentary: Identification of potential new antimicrobials is challenging; however, one source for potential structurally diverse and complex antimicrobials are natural products. Natural products may have advantages over other post-germ theory antimicrobials. Many antimicrobial herbal medicines possess simultaneous antibacterial, antifungal, antiprotozoal and/or antiviral properties. Herbal products have the potential to boost host resistance to infections, particularly in immunocompromised patients. Antimicrobial broad-spectrum activity in conjunction with immunostimulatory properties may help to prevent microbial resistance to herbal medicine. As part of the efforts to broaden use of herbal medicines to treat microbial infections, pre-clinical and clinical testing guidelines of these compounds as a whole should be implemented to ensure consistency in formulation, efficacy and safety.

Anti-herpes simplex virus type 1 activity of Houttuynoid A, a flavonoid from Houttuynia cordata Thunb

Early events in herpes simplex virus type 1 (HSV-1) infection reactivate latent human immunodeficiency virus, Epstein-Barr virus, and human papillomavirus in the presence of acyclovir (ACV). The common use of nucleoside analog medications, such as ACV and pencyclovir, has resulted in the emergence of drug-resistant HSV-1 strains in clinical therapy. Therefore, new antiherpetics that can inhibit early events in HSV-1 infection should be developed. An example of this treatment is Houttuynia cordata Thunb. water extract, which can inhibit HSV-1 infection through multiple mechanisms. In this study, the anti-HSV-1 activity of Houttuynoid A, a new type of flavonoid isolated from H. cordata, was investigated. Three different assays confirmed that this compound could exhibit strong in vitro anti-HSV-1 activity. One assay verified that this compound could inhibit HSV-1 multiplication and prevent lesion formation in a HSV-1 infection mouse model. Mechanism analysis revealed that this compound could inactivate HSV-1 infectivity by blocking viral membrane fusion. Moreover, Houttuynoid A exhibited antiviral activities against other alpha herpes viruses, such as HSV-2 and varicella zoster virus (VZV). In conclusion, Houttuynoid A may be a useful antiviral agent for HSV-1.

Preventive Effects of Houttuynia cordata Extract for Oral Infectious Diseases

Houttuynia cordata (HC) (Saururaceae) has been used internally and externally as a traditional medicine and as an herbal tea for healthcare in Japan. Our recent survey showed that HC poultice (HCP) prepared from smothering fresh leaves of HC had been frequently used for the treatment of purulent skin diseases with high effectiveness. Our experimental study also demonstrated that ethanol extract of HCP (eHCP) has antibacterial, antibiofilm, and anti-inflammatory effects against S. aureus which caused purulent skin diseases. In this study, we focused on novel effects of HCP against oral infectious diseases, such as periodontal disease and dental caries. We determined the antimicrobial and antibiofilm effects of water solution of HCP ethanol extract (wHCP) against important oral pathogens and investigated its cytotoxicity and anti-inflammatory effects on human oral epithelial cells. wHCP had moderate antimicrobial effects against some oral microorganisms and profound antibiofilm effects against Fusobacterium nucleatum, Streptococcus mutans, and Candida albicans. In addition, wHCP had no cytotoxic effects and could inhibit interleukin-8 and CCL20 productions by Porphyromonas gingivalis lipopolysaccharide-stimulated human oral keratinocytes. Our findings suggested that wHCP may be clinically useful for preventing oral infectious diseases as a mouthwash for oral care.