Deoxyshikonin: a promising lead drug grass against drug resistance or sensitivity to Helicobacter pylori in an acidic environment.

Helicobacter pylori (H. pylori) is closely associated with the diseases such as gastric sinusitis, peptic ulcers, and gastric adenocarcinoma. Its drug resistance is very severe, and new antibiotics are urgently needed. Nine comfrey compounds were screened by antimicrobial susceptibility testing, among which deoxyshikonin had the best inhibitory effect, with a minimum inhibitory concentration (MIC) of 0.5-1 µg/mL. In addition, deoxyshikonin also has a good antibacterial effect in an acidic environment, it is highly safe, and H. pylori does not readily develop drug resistance. Through in vivo experiments, it was proven that deoxyshikonin (7 mg/kg) had a beneficial therapeutic effect on acute gastritis in mice infected with the multidrug-resistant H. pylori BS001 strain. After treatment with desoxyshikonin, colonization of H. pylori in the gastric mucosa of mice was significantly reduced, gastric mucosal damage was repaired, inflammatory factors were reduced, and the treatment effect was better than that of standard triple therapy. Therefore, deoxyshikonin is a promising lead drug to solve the difficulty of drug resistance in H. pylori, and its antibacterial mechanism may be to destroy the biofilm and cause an oxidation reaction.

Detection performance of PCR for Legionella pneumophila in environmental samples: a systematic review and meta-analysis.

BACKGROUND: Legionellosis remains a public health problem. The most common diagnostic method to detect Legionella pneumophila (L. pneumophila) is culture. Polymerase chain reaction (PCR) is a fast and accurate method for this detection in environmental samples. METHODS: Four databases were searched for studies that evaluated the detection efficiency of PCR in L. pneumophila. The quality evaluation was conducted using Review Manager 5.3. We used Meta-DiSc 1.4 software and the Stata 15.0 software to create forest plots, a meta-regression, a bivariate boxplot and a Deeks' funnel plot. RESULTS: A total of 18 four-fold tables from 16 studies were analysed. The overall pooled sensitivity and specificity of PCR was 94% and 72%, respectively. The positive likelihood ratio (RLR) and negative likelihood ratio (NLR) was 2.73 and 0.12, respectively. The result of the diagnostic odds ratio (DOR) was 22.85 and the area under the curve (AUC) was 0.7884. CONCLUSION: Establishing a laboratory diagnostic tool for L. pneumophila detection is important for epidemiological studies. In this work, PCR demonstrated a promising diagnostic accuracy for L. pneumophila.

Cinnamaldehyde: An effective component of Cinnamomum cassia inhibiting Helicobacter pylori.

ETHNOPHARMACOLOGICAL RELEVANCE: Cinnamomum cassia Presl (Cinnamomum cassia) is a common traditional Chinese medicine, which can promote the secretion and digestion of gastric juice, improve the function of gastrointestinal tract. Cinnamaldehyde (CA) is a synthetic food flavoring in the Chinese Pharmacopoeia. AIM OF THE STUDY: This study aimed to search for the active ingredient (CA) of inhibiting H. pylori from Cinnamomum cassia, and elucidate mechanism of action, so as to provide the experimental basis for the treatment of H. pylori infection with Cinnamomum cassia. MATERIALS AND METHODS: It's in vitro and in vivo pharmacological properties were evaluated based on minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and an acute gastric inflammation model in mice infected with H. pylori. Drug safety was evaluated using the CCK8 method and high-dose administration in mice. The advantageous characteristics of CA in inhibiting H. pylori were confirmed using acidic conditions and in combination with the antibiotics. The mechanism underlying the action of CA on H. pylori was explored using scanning electron microscopy (SEM), adhesion experiments, biofilm inhibition tests, ATP and ROS release experiments, and drug affinity responsive target stability (DARTS) screening of target proteins. The protein function and target genes were verified by molecular docking and Real-Time quantitative reverse transcription PCR (qRT-PCR). RESULTS: The results demonstrated that CA was found to be the main active ingredient against H. pylori in Cinnamomum cassia in-vitro tests, with a MIC of 8-16 µg/mL. Moreover, CA effectively inhibited both sensitive and resistant H. pylori strains. The dual therapy of PPI + CA exhibited remarkable in vivo efficacy in the acute gastritis mouse model, superior to the standard triple therapy. DARTS, molecular docking, and qRT-PCR results suggested that the target sites of action were closely associated with GyrA, GyrB, AtpA, and TopA, which made DNA replication and transcription impossible, then leading to inhibition of bacterial adhesion and colonization, suppression of biofilm formation, and inhibition ATP and enhancing ROS. CONCLUSIONS: This study demonstrated the suitability of CA as a promising lead drug against H. pylori, The main mechanisms can target GyrA ect, leading to reduce ATP and produce ROS, which induces the apoptosis of bacterial.

Linolenic acid-metronidazole inhibits the growth of Helicobacter pylori through oxidation.

BACKGROUND: Resistance to antibiotics is one the main factors constraining the treatment and control of Helicobacter pylori (H. pylori) infections. Therefore, there is an urgent need to develop new antimicrobial agents to replace antibiotics. Our previous study found that linolenic acid-metronidazole (Lla-Met) has a good antibacterial effect against H. pylori, both antibiotic-resistant and sensitive H. pylori. Also, H. pylori does not develop resistance to Lla-Met. Therefore, it could be used for preparing broad-spectrum antibacterial agents. However, since the antibacterial mechanism of Lla-Met is not well understood, we explored this phenomenon in the present study. AIM: To understand the antimicrobial effect of Lla-Met and how this could be applied in treating corresponding infections. METHODS: H. pylori cells were treated with the Lla-Met compound, and the effect of the compound on the cell morphology, cell membrane permeability, and oxidation of the bacteria cell was assessed. Meanwhile, the differently expressed genes in H. pylori in response to Lla-Met treatment were identified. RESULTS: Lla-Met treatment induced several changes in H. pylori cells, including roughening and swelling. In vivo experiments revealed that Lla-Met induced oxidation, DNA fragmentation, and phosphatidylserine ectropionation in H. pylori cells. Inhibiting Lla-Met with L-cysteine abrogated the above phenomena. Transcriptome analysis revealed that Lla-Met treatment up-regulated the expression of superoxide dismutase SodB and MdaB genes, both anti-oxidation-related genes. CONCLUSION: Lla-Met kills H. pylori mainly by inducing oxidative stress, DNA damage, phosphatidylserine ectropionation, and changes on cell morphology.

BanXiaXieXin decoction treating gastritis mice with drug-resistant Helicobacter pylori and its mechanism.

BACKGROUND: Helicobacter pylori (H. pylori) is the main pathogen that causes a variety of upper digestive diseases. The drug resistance rate of H. pylori is increasingly higher, and the eradication rate is increasingly lower. The antimicrobial resistance of H. pylori is an urgent global problem. It has been confirmed that Banxia Xiexin decoction (BXXXT) demonstrates the effects of treating gastrointestinal diseases, inhibiting H. pylori and protecting gastric mucosa. The purpose of the present study is to further explore the therapeutic effects of BXXXT on drug-resistant H. pylori. AIM: To confirm that BXXXT demonstrates therapeutical effects in vivo and in vitro on gastritis mice with drug-resistant H. pylori and explain its mechanism to provide an experimental basis for promoting the application of BXXXT. METHODS: The aqueous extract of BXXXT was gained by water decocting method. The inhibitory effect of the aqueous extract on H. pylori was detected by dilution in vitro; drug-resistant H. pylori cells were used to build an acute gastritis model in vivo. Thereafter, the model mice were treated with the aqueous extract of BXXXT. The amount of H. pylori colonization, the repair of gastric mucosal damage, changes of inflammatory factors, apoptosis, etc., were assessed. In terms of mechanism exploration, the main medicinal compositions of BXXXT aqueous extract and the synergistic bacteriostatic effects they had demonstrated were analyzed using mass spectrometry; the immune function of peripheral blood cells such as CD3+ T and CD4+ T of mice with gastritis before and after treatment with BXXXT aqueous extract was detected using a flow cytometry; the H. pylori transcriptome and proteome after treatment with BXXXT aqueous extract were detected. Differently expressed genes were screened and verification was performed thereon with knockout expression. RESULTS: The minimum inhibitory concentration of BXXXT aqueous extract against H. pylori was 256-512 µg/mL. A dose of 28 mg/kg BXXXT aqueous extract treatment produced better therapeutical effects than the standard triple therapy did; the BXXXT aqueous extract have at least 11 ingredients inhibiting H. pylori, including berberine, quercetin, baicalin, luteolin, gallic acid, rosmarinic acid, aloe emodin, etc., of which berberine, aloe emodin, luteolin and gallic acid have a synergistic effect; BXXXT aqueous extract was found to stimulate the expressions of CD3+ T and CD4+ T and increase the number of CD4+ T/CD8+ T in gastritis mice; the detection of transcriptome and proteome, quantitative polymerase chain reaction, Western blotting and knockout verification revealed that the main targets of BXXXT aqueous extract are CFAs related to urea enzymes, and CagA, VacA, etc. CONCLUSION: BXXXT aqueous extract could demonstrate good therapeutic effects on drug-resistance H. pylori in vitro and in vivo and its mechanism comes down to the synergistic or additional antibacterial effects of berberine, emodin and luteolin, the main components of the extract; the extract could activate the immune function and enhance bactericidal effects; BXXXT aqueous extract, with main targets of BXXXT aqueous extract related to urease, virulence factors, etc., could reduce the urease and virulence of H. pylori, weaken its colonization, and reduce its inflammatory damage to the gastric mucosa.

Therapeutic effect of demethylated hydroxylated phillygenin derivative on Helicobacter pylori infection.

Modifying and transforming natural antibacterial products is a novel idea for developing new efficacious compounds. Phillygenin has an inhibitory effect on H. pylori. The aim of the present study was to prepare a phillygenin derivative (PHI-Der) through demethylation and hydroxylation. The minimum inhibitory concentration of 18 strains of H. pylori from different sources was 8-32 µg/mL in vitro, and the activity increased 2-8 times than that of phillygenin. PHI-Der could significantly inhibit the colonization of H. pylori in vivo, reduce the inflammatory response, and promote the repair of inflammatory damage. Further, we used SwissTargetPrediction to predict that its main targets are ALOX5, MCL1, and SLC6A4, and find that it can inhibit bacterial biofilm formation and reduce bacterial infection of cells. It can enhance the intracellular oxidative capacity of H. pylori to inhibit H. pylori growth. Further, it could prevent the oxidation of H. pylori-infected cells and reduce the inflammatory response, which plays a role in protection. In conclusion, compared to phillygenin, PHI-Der had better antibacterial activity and was more effective in treating H. pylori infection. It has characteristics of high safety, specificity, resistance to drug resistance and better antibacterial activity than phillygenin, it's a good antioxidant for host cells.

Effect of BCG Vaccination against SARS-CoV-2 Infection.

Based on previous studies, we found that Bacillus Calmette-Guérin (BCG) vaccination may play a role in preventing SARS-CoV-2 infection. Therefore, we conducted a meta-analysis to investigate this protective effect. We searched the Embase, PubMed, Web of Science, Cochrane Library, BioRxiv, and MedRxiv databases for studies that evaluated the relationship between BCG vaccination and SARS-CoV-2 infection or COVID-19 disease. The quality of all included studies was assessed using the Risk of Bias in Non-randomized Studies of Interventions and the Agency for Healthcare Research and Quality data tools. Review Manager (Version 5.3) was used to conduct all the data analyses. A total of eight studies were ultimately included in our meta-analysis. Our primary analysis found a significantly lower SARS-CoV-2 infection rate in the BCG vaccination group compared to the control group, with an odds ratio of 0.61, (95% confidence interval 0.39 to 0.95, P = 0.03; I2 = 31%, and P = 0.21, respectively). Our study indicates that BCG vaccination can protect against SARS-CoV-2 infection. However, there is insufficient evidence that BCG vaccination can reduce the severity of COVID-19.

Phillygenin Inhibits Helicobacter pylori by Preventing Biofilm Formation and Inducing ATP Leakage.

With the widespread use and abuse of antibiotics, Helicobacter pylori (H. pylori) has become seriously drug resistant. The development of new antibiotics is an important way to solve H. pylori's drug resistance. Screening antibacterial ingredients from natural products is a convenient way to develop new antibiotics. Phillygenin, an effective antibacterial component, was selected from the natural product, forsythia, in this study. Its minimal inhibitory concentration (MIC) for 18 H. pylori strains was 16-32 µg/ml. The minimum bactericidal concentration (MBC) of H. pylori G27 was 128 µg/ml; the higher the drug concentration and the longer the time, the better the sterilization effect. It was non-toxic to gastric epithelial cell (GES)-1 and BGC823 cells at the concentration of 100 µg/ml. It presented a better antibacterial effect on H. pylori in an acidic environment, and after 24 days of induction on H. pylori with 1/4 MIC of phillygenin, no change was found in the MIC of H. pylori. In the mechanism of action, phillygenin could cause ATP leakage and inhibit the biofilm formation; the latter was associated with the regulation of spoT and Hp1174 genes. In addition, phillygenin could regulate the genes of Nhac, caggamma, MATE, MdoB, flagellinA, and lptB, leading to the weakening of H. pylori's acid resistance and virulence, the diminishing of H. pylori's capacity for drug efflux, H. pylori's DNA methylation, the initiation of human immune response, and the ATP leakage of H. pylori, thus accelerating the death of H. pylori. In conclusion, phillygenin was a main ingredient inhibiting H. pylori in Forsythia suspensa, with a good antibacterial activity, high safety, strong specificity, better antibacterial effect under acidic conditions, and low risk of resistance development by H. pylori. Its mechanism of action was mainly associated with inhibiting the biofilm formation and resulting in ATP leakage. In addition, phillygenin was shown to be able to reduce the acid resistance and virulence of H. pylori.

Production of ε-poly-L: -lysine using a novel two-stage pH control strategy by Streptomyces sp. M-Z18 from glycerol.

The production of ε-poly-L: -lysine (ε-PL) by Streptomyces sp. M-Z18 from glycerol was investigated in a 5-L jar-fermenter. Batch fermentations by Streptomyces sp. M-Z18 at various pH values ranging from 3.5 to 4.5 were studied. Based on the analysis of the time course of specific cell growth rate and specific ε-PL formation rate, a novel two-stage pH control strategy was developed to improve ε-PL production by shifting the culture pH from 3.5 to 3.8 after 36 h of cultivation. By applying the strategy, the maximal ε-PL concentration and productivity had a significant improvement and reached 9.13 g L(-1) and 4.76 g L(-1) day(-1), respectively, compared with those in one-stage pH control process where the pH value is controlled at 3.5 (7.83 g L(-1) and 3.13 g L(-1) day(-1)). Fed-batch fermentation with two-stage pH control strategy was also applied to produce ε-PL; final ε-PL concentration of 30.11 g L(-1) was obtained, being 3.3-fold greater than that of batch fermentation. To our knowledge, it is the first report on production of ε-PL from glycerol in fermenter scale and achievement of high ε-PL production with two-stage pH control strategy.