Sodium New Houttuyfonate Affects Transcriptome and Virulence Factors of Pseudomonas aeruginosa Controlled by Quorum Sensing

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.

Effect of traditional Chinese medicine monomers interfering with quorum-sensing on virulence factors of extensively drug-resistant Acinetobacter baumannii

The antimicrobial resistance of Acinetobacter baumannii (A. baumannii) clinical isolates has emerged as a great threat to public health. Quorum sensing (QS) is one of the resistance mechanisms for drug-resistant A. baumannii. Interfering with QS is a promising strategy to combat infections caused by drug-resistant bacteria. This study explored the QS inhibition ability of thirty-four traditional Chinese medicine monomers (TCMMs) and assessed the effect of QS inhibitors (QSIs) on the virulence factors of twelve extensively drug-resistant A. baumannii (XDRAB) strains. Nine traditional Chinese medicine monomers, such as caffeic acid, cinnamic acid, and myricetin, were found to be able to inhibit the bacterial QS. Then, at 1/8 of the minimal inhibitory concentration, we found that these QSIs inhibited extensively drug-resistant A. baumannii adhesion and biofilm formation and downregulated the expression levels of virulence-associated genes (abaI, abaR, csuE, pgaA, and bap). In conclusion, nine traditional Chinese medicine monomers have QS inhibitory activity and may downregulate QS genes to interfere with the QS system, which could inhibit the expression of extensively drug-resistant A. baumannii virulence factors. These results suggest that traditional Chinese medicine monomers could develop as novel anti-virulence compounds to control extensively drug-resistant A. baumannii infections.

The sodium new houttuyfonate suppresses NSCLC via activating pyroptosis through TCONS-14036/miR-1228-5p/PRKCDBP pathway

Several studies have suggested the potential value of Houttuynia cordata as a therapeutic agent in lung cancer, but direct evidence is still lacking. The study aimed to determine the regulatory impact of a major H. cordata constituent derivative (sodium new houttuyfonate [SNH]) on lncRNA networks in non-small cell lung cancer (NSCLC) to identify new potential therapeutic targets. After exposing NSCLC cells to SNH, we analysed the following: cell death (via flow cytometry, TUNEL and ASC speck formation assays), immune factors (via ELISA), gene transcription (via RT-qPCR), subcellular localisation (via FISH), gene-gene and gene-protein interactions (via dual-luciferase reporter and RNA immunoprecipitation assays, respectively) and protein expression and distribution (via western blotting and immunocytochemistry or immunohistochemistry). In addition, statistical analysis (via one-way ANOVA or unpaired t-tests) was performed. Exposure to SNH promoted NSCLC cell pyroptosis, concomitant with significant up-regulation of TCONS-14036, a novel lncRNA. Mechanistic research demonstrated that TCONS-14036 functions as a competing endogenous (ce)RNA by sequestering microRNA (miR)-1228-5p, thereby up-regulating PRKCDBP-encoding transcript levels. Indeed, PRKCDBP promoted pyroptosis by activating the NLRP3 inflammasome, resulting in CASP1, IL-1β and GSDMD cleavage. Our findings elucidate the potential molecular mechanisms underlying the ability of SNH to suppress NSCLC growth through activation of pyroptosis via the TCONS-14036/miR-1228-5p/PRKCDBP pathway. Thus, we identify a new potential therapeutic targets for NSCLC.

Targeting Multidrug-Recalcitrant Pseudomonas aeruginosa Biofilms: Combined-Enzyme Treatment Enhances Antibiotic Efficacy

Pseudomonas aeruginosa is an opportunistic pathogen that forms biofilms during infection, resulting in recalcitrance to antibiotic treatment. Biofilm inhibition is a promising research direction for the treatment of biofilm-associated infections. Here, a combined-enzyme biofilm-targeted strategy was put forward for the first time to simultaneously prevent biofilm formation and break down preformed biofilms. The N-acylhomoserine lactonase AidH was used as a quorum-sensing inhibitor and was modified to enhance the inhibitory effect on biofilms by rational design. Mutant AidH_A147G exerted maximum activity at the human body temperature and pH and could reduce the expression of virulence factors as well as biofilm-related genes of P. aeruginosa. Subsequently, the P. aeruginosa self-produced glycosyl hydrolase PslG joined with AidH_A147G to disrupt biofilms. Interestingly, under the combined-enzyme intervention for P. aeruginosa wild-type strain PAO1 and clinical strains, no biofilm was observed on the bottom of NEST glass-bottom cell culture dishes. The combination strategy also helped multidrug-resistant clinical strains change from resistant to intermediate or sensitive to many antibiotics commonly used in clinical practice. These results demonstrated that the combined-enzyme approach for inhibiting biofilms is a potential clinical treatment for P. aeruginosa infection.

Sodium New Houttuyfonate Inhibits Cancer-Promoting Fusobacterium nucleatum (Fn) to Reduce Colorectal Cancer Progression

Colorectal cancer (CRC) is a major cause of morbidity and mortality worldwide. Recent studies showed that the common anaerobe Fusobacterium nucleatum (Fn) is closely associated with a higher risk for carcinogenesis, metastasis, and chemoresistance of CRC. However, there is no specific antimicrobial therapy for CRC treatment. Herbal medicine has a long history of treating diseases with remarkable effects and is attracting extensive attention. In this study, we tested six common phytochemicals for their antimicrobial activities against Fn and whether anti-Fn phytochemicals can modulate CRC development associated with Fn. Among these antimicrobials, we found that SNH showed the highest antimicrobial activity and little cytotoxicity toward cancer cells and normal cells in vitro and in vivo. Mechanistically, SNH may target membrane-associated FadA, leading to FadA oligomerization, membrane fragmentation and permeabilization. More importantly, SNH blocked the tumor-promoting activity of Fn and Fn-associated cancer-driven inflammation, thus improving the intestinal barrier damaged by Fn. SNH reduced Fn load in the CRC-cells-derived mice xenografts with Fn inoculation and significantly inhibited CRC progression. Our data suggest that SNH could be used for an antimicrobial therapy that inhibits Fn and cancer-driven inflammation of CRC. Our results provide an important foundation for future gut microbiota-targeted clinical treatment of CRC.

Antifungal Activity of Sodium New Houttuyfonate Against Aspergillus fumigatus in vitro and in vivo

Aspergillus fumigatus is an important pathogen causing invasive aspergillosis, which is associated with high morbidity and mortality in immunocompromised people. However, the treatment of A. fumigatus infection is a growing challenge, owing to the limited availability antifungal agents and the continual emergence of drug-resistant strains. Drug repurposing is a potential strategy to solve this current problem. Sodium new houttuyfonate (SNH), derived from houttuynin, extracted from Houttuynia cordata, has anti-bacterial and anti-Candida albicans effects. However, whether it has anti-A. fumigatus activity had not been reported. In this study, the antifungal properties of SNH against A. fumigatus, including the standard strain AF293, itraconazole resistant clinical strains, and voriconazole resistant clinical strains, were evaluated in vitro and in vivo. Moreover, the potential mechanism of SNH was characterized. SNH exhibited significant fungicidal activity toward various A. fumigatus strains. SNH also inhibited fungal growth, sporulation, conidial germination and pigment formation, and biofilm formation. Further investigations revealed that SNH interfered with the A. fumigatus cell steroid synthesis pathway, as indicated by transcriptomic and quantitative real-time polymerase chain reaction analyses, and inhibited ergosterol synthesis, as indicated by cell membrane stress assays and ergosterol quantification. Moreover, daily gastric gavage of SNH significantly decreased the fungal burden in mice with disseminated infection (kidney, liver, and lung) and local tissue damage. In addition, the application of SNH downregulated the production of IL-6 and IL-17A. Together, these findings provided the first confirmation that SNH may be a promising antifungal agent for the treatment of A. fumigatus infection.

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.

Inhibitory effects of sodium new houttuyfonate on growth and biofilm formation of Streptococcus mutans

The present study aimed to assess the impact of sodium new houttuyfonate (SNH) on growth and biofilm formation of Streptococcus mutans, and the combinatorial effects of SNH with cariostatic agents. The effects of SNH on S. mutans planktonic cultures were assessed by growth curve assay. The effects of SNH on S. mutans biofilm and extracellular polysaccharides (EPS) production were observed via crystal violet (CV) assay, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, colony-forming unit (CFU) counting assay, scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). Quantitative real-time polymerase chain reaction (qPCR) was applied to investigate the regulatory effects of SNH on the expression of virulence genes of S. mutans. Checkerboard microdilution assay was performed to investigate the combinatorial effects of SNH with two common cariostatic agents. SNH acted as an inhibitor on planktonic cell growth, biofilm formation and EPS production of S. mutans. SNH also downregulated the expression of gtfBCD and comDE systems and exhibited synergism with chlorhexidine (CHX). In conclusion, this study indicated a possibility for SNH to become an anticaries agents by its antimicrobial activity and synergistic effects with CHX against S. mutans.