Effect of in vitro simulated digestion on the anti-Helicobacter Pylori activity of different Propolis extracts

Helicobacter pylori (HP) is among the most common pathogens causing infection in humans worldwide. Oxidative stress and gastric inflammation are involved in the progression of HP-related gastric diseases, and they can be targeted by integrating conventional antibiotic treatment with polyphenol-enriched natural products. In this work, we characterised three different propolis extracts and evaluated their stability under in vitro simulated gastric digestion, compared to their main constituents alone. The extract with the highest stability to digestion (namely, the dark propolis extract, DPE) showed a minimum bactericidal concentration (MBC) lower than 1 mg/mL on HP strains with different virulence factors. Finally, since urease is one of the virulence factors contributing to the establishment of a microenvironment that promotes HP infection, we evaluated the possible inhibition of this enzyme by using molecular docking simulations and in vitro colorimetric assay, showing that galangin and pinocembrin may be involved in this activity.

Fucoidan from Sargassum hemiphyllum inhibits infection and inflammation of Helicobacter pylori

Having infected by Helicobacter pylori, the infection often leads to gastritis, gastric ulcer, or even gastric cancer. The disease is typically treated with antibiotics as they used to effectively inhibit or kill H. pylori, thus reducing the incidence of gastric adenoma and cancer to significant extent. H. pylori, however, has developed drug resistance to many clinically used antibiotics over the years, highlighting the crisis of antibiotic failure during the H. pylori treatment. We report here that the fucoidan from Sargassum hemiphyllum can significantly reduce the infection of H. pylori without developing to drug resistance. Fucoidan appears to be a strong anti-inflammation agent as manifested by the RAW264.7 cell model examination. Fucoidan can prohibit H. pylori adhesion to host cells, thereby reducing the infection rate by 60%, especially in post treatment in the AGS cell model assay. Mechanistically, fucoidan intervenes the adhesion of BabA and AlpA of H. pylori significantly lowering the total count of H. pylori and the level of IL-6 and TNF-α in vivo. These results all converge on the same fact that fucoidan is an effective agent in a position to protect the stomach from the H. pylori infection by reducing both the total count and induced inflammation.

Development of a microbial coating for cellulosic surface using aloe vera and silane

The highly contagious nature of SARS-CoV-2 (COVID-19) virus has created a havoc effect all over the world in a very short period. The most effective method for precaution of this virus as suggested by WHO is use of PPEs (triple layered face mask, body suits) and social distancing. However, the frontline doctors and medical staff have high risk of exposure to the virus during treatments and removal and discarding of the PPEs. Also the PPEs are of the onetime use and wearing these PPEs in hot and humid seasons is very uncomfortable. A possible solution of this problem is if clothes are anti-bacterial and anti-viral in nature, one single-layered will be sufficient and the spread of virus will also be minimized. Considering this, we have designed a facile and durable anti-wash antimicrobial coating on cloth by aloe vera and hexadecyltrimethoxysilane (HDTMS). In lab scale study, present coating shows good chemical and thermal stability making it reusable multiple times even after repeated washing. The coated cloth reveals the excellent anti-dirt and stain resistance properties leading to complete non-adherence of dirt and stain (e.g. Color, food, ink) on it. Anti-bacterial and anti-fungi properties of the coated cloth were confirmed by doing E. coli (bacteria) and A. Niger (fungus) culture studies, respectively. This coating is imbibed with well-known anti-viral agent aloe vera which inhibits the attachment of the virus on the surface. The water-repellent nature of the coating combined with the use anti-viral agent, aloe vera makes it a potential anti-COVID-19 coating.

Probiotic Lactobacillus fermentum UCO-979C biofilm formation on AGS and Caco-2 cells and Helicobacter pylori inhibition

The ability of the human isolate Lactobacillus fermentum UCO-979C to form biofilm and synthesize exopolysaccharide on abiotic and biotic models is described. These properties were compared with the well-known Lactobacillus casei Shirota to better understand their anti-Helicobacter pylori probiotic activities. The two strains of lactobacilli synthesized exopolysaccharide as detected by the Dubois method and formed biofilm on abiotic and biotic surfaces visualized by crystal violet staining and scanning electron microscopy. Concomitantly, these strains inhibited H. pylori urease activity by up to 80.4% (strain UCO-979C) and 66.8% (strain Shirota) in gastric adenocarcinoma (AGS) cells, but the two species showed equal levels of inhibition (~84%) in colorectal adenocarcinoma (Caco-2) cells. The results suggest that L. fermentum UCO-979C has probiotic potential against H. pylori infections. However, further analyses are needed to explain the increased activity observed against the pathogen in AGS cells as compared to L. casei Shirota.

Modification of drug delivery to improve antibiotic targeting to the stomach

The obstacles to the successful eradication of Helicobacter pylori infections include the presence of antibiotic-resistant bacteria and therapy requiring multiple drugs with complicated dosing schedules. Other obstacles include bacterial residence in an environment where high antibiotic concentrations are difficult to achieve. Biofilm production by the bacteria is an additional challenge to the effective treatment of this infection. Conventional oral formulations used in the treatment of this infection have a short gastric residence time, thus limiting the duration of exposure of drug to the bacteria. This review summarizes the current research in the development of gastroretentive formulations and the prospective future applications of this approach in the targeted delivery of drugs such as antibiotics to the stomach.

In vitro activity of Aloe vera inner gel against microorganisms grown in planktonic and sessile phases

The failure of traditional antimicrobial treatments is becoming a worldwide problem. The use of Aloe vera is of particular interest for its role as curative agent and its efficacy in complementary therapies for a variety of illnesses. This study evaluated the antimicrobial activity of A. vera inner gel against a panel of microorganisms, Gram-positive and -negative bacteria, and Candida albicans. In addition to A. vera inner gel being used in the treatment of peptic ulcers, in dermatological treatments, and wound healing, it was also tested on the sessile phase of clinical Helicobacter pylori strains (including multi-drug-resistant strains) and on planktonic and sessile phase of Staphylococcus aureus/Pseudomonas aeruginosa clinical isolates from venous leg ulcers.A. vera inner gel expresses its prevalent activity against Gram-negative bacteria and C. albicans in respect to Gram-positive bacteria. The results of the A. vera antibiofilm activity showed a decrease of the produced biomass in a concentration-dependent-way, in each analyzed microorganism. The data obtained show that A. vera inner gel has both an antimicrobial and antibiofilm activity suggesting its potential use for the treatment of microbial infections, in particular for H. pylori gastric infection, especially in case of multi-drug-resistance, as well as for an effective wound dressing.

Inhibition of Helicobacter pylori growth and its colonization factors by Parthenium hysterophorus extracts

ETHNOPHARMACOLOGICAL RELEVANCE

Parthenium hysterophorus (Asteraceae) is a traditional medicinal plant used to treat gastrointestinal disorders, such as gastritis. Helicobacter pylori have been described as the etiological agent of gastritis, peptic ulcer, as well as gastric adenocarcinoma. 50% of the world's population is infected with this bacterium and the current therapy fails due to the increment in antibiotic resistance; therefore, it is necessary to find new approaches to control H. pylori infection, either by its eradication or by preventing the bacterial colonization.

AIM OF THE STUDY

To investigate the effect of P. hysterophorus extracts on H. pylori growth and upon its colonization-related factors.

MATERIALS AND METHODS

Five different polarity extracts from roots and aerial parts of P. hysterophorus were evaluated in vitro against H. pylori growth by the broth dilution method. Anti-colonization activities were determined as follows: motility in soft agar plates, urease activity by ammonia colorimetrical quantification, and adherence of FITC labeled H. pylori to AGS cells by fluorometrical measurement.

RESULTS

Organic extracts inhibited H. pylori growth. Particularly, the dichloromethane extract from roots showed a MIC of 15.6 µg/ml while the aqueous extracts showed low or null activity. There is a direct correlation between antibacterial activity and inhibition of motility. Urease activity was partially inhibited by organic extracts, at best 46%, except for the roots dichloromethane extract which reached 74% of inhibition with 500 µg/ml (IC50=136.4 µg/ml). Plant extracts inhibited adherence in different ranges but the dichloromethane-methanol ones possessed the highest effect, with a 70% maximal inhibition at 1mg/ml.

CONCLUSION

The results indicate that some P. hysterophorus extracts have various biological activities that could act synergistically against H. pylori. This work contributes to the ethnomedical knowledge of this species and underlines the potential of some organic extracts as a good source for the isolation of bioactive compounds.

Hepatoprotective potential of Aloe vera polysaccharides against chronic alcohol-induced hepatotoxicity in mice

BACKGROUND

Aloe vera polysaccharides are reported to exhibit multiple biological effects, including anti-oxidation, anti-inflammation and immune enhancement. However, their influence on alcoholic liver disease (ALD) remains unclear. This study was designed to determine the protective effect of extracted A. vera polysaccharides (AVGP) against ALD in a chronic alcohol-feeding mouse model and investigate the possible underlying mechanisms.

RESULTS

Supplementation of AVGP significantly attenuated the levels of serum aminotransferases, lipids and hepatic TG and ameliorated histopathological alterations in the model of ALD. Interestingly, AVGP markedly up-regulated hepatic expression of lipolytic genes (AMPK-α2 and PPAR-α) but had no effect on lipogenic gene expression. AVGP diminished alcohol-dependent oxidative stress partly through a decrease in MDA and increase in GSH and SOD. Alcohol-induced inflammation was also mitigated by AVGP treatment via significant reduction in LPS and TNF-α, down-regulation of TLR-4 and MyD88 and up-regulation of IκB-α.

CONCLUSION

This study clearly showed that AVGP exerts a potent protective effect against chronic alcohol-induced liver injury. Its hepatoprotective effect appears to be associated with its antioxidant capacity and its ability to accelerate lipolysis and inhibit inflammatory response. The results indicate that AVGP could be considered as a potent food supplement in the prevention of ALD.

In vitro activity of Aloe vera inner gel against Helicobacter pylori strains

Aloe barbadensis Miller (Aloe vera) is a herbal remedy widely used for a variety of illnesses; A. vera leaf extracts have been promoted for detoxification, cure constipation, help flush out toxins and wastes from the body, promote digestion and are used in the treatment of peptic ulcer for cytoprotective action. The aim of this study was to evaluate the antibacterial activity of A. vera inner gel against both susceptible and resistant Helicobacter pylori strains isolated in Abruzzo region, Italy. The inner gel of leaves of a 5-year-old plant of A. vera was extracted, homogenized and tested from 800 to 1.56 mg ml(-1) against 14 clinical strains and one reference strain of H. pylori using the broth microdilution methodology. Furthermore, the sample of A. vera was investigated for the chemical fingerprint of anthraquinones. The inhibitory concentrations of A. vera inner gel were similar to the bactericidal ones, with values ranging from 6.25 to 800 mg ml(-1) . Fifty per cent of the detected strains, independently of their susceptibility profile, were inhibited in their growth at 100 mg ml(-1) . Aloe vera inner gel expresses antibacterial properties against H. pylori and, therefore, in combination with antibiotics, could represent a novel strategy for the treatment of the infection of H. pylori, especially in cases of multiresistance.

SIGNIFICANCE AND IMPACT OF THE STUDY

The study demonstrates that the Aloe vera inner gel expresses antibacterial properties against both susceptible and resistant Helicobacter pylori strains. These findings may impact on the antimicrobial resistance phenomenon of H. pylori, proposing the A. vera inner gel as a novel effective natural agent for combination with antibiotics for the treatment of H. pylori gastric infection.

Antibiofilm polysaccharides

Bacterial extracellular polysaccharides have been shown to mediate many of the cell-to-cell and cell-to-surface interactions that are required for the formation, cohesion and stabilization of bacterial biofilms. However, recent studies have identified several bacterial polysaccharides that inhibit biofilm formation by a wide spectrum of bacteria and fungi both in vitro and in vivo. This review discusses the composition, modes of action and potential biological roles of antibiofilm polysaccharides recently identified in bacteria and eukarya. Some of these molecules may have technological applications as antibiofilm agents in industry and medicine.

Effects of Ganoderma lucidum polysaccharides on IEC-6 cell proliferation, migration and morphology of differentiation benefiting intestinal epithelium healing in vitro

OBJECTIVES

Restoration of epithelial continuity in the intestinal surface after extensive destruction is important since intestinal epithelial cells stand as a boundary between the body's internal and external environment. Polysaccharides from Ganoderma lucidum (Gl-PS) may benefit intestinal epithelial wound healing in different aspects, which awaits clarification. To identify potential effects, a non-transformed small-intestinal epithelial cell line, IEC-6 cells, was used.

METHODS

Effects on epithelial cell proliferation, migration, morphology of differentiation and transforming growth factor beta (TGF-β) protein expression, as well as the cellular ornithine decarboxylase (ODC) mRNA and c-Myc mRNA expression, were assessed, respectively, by MTT assay, wound model in vitro, observation under a microscope after hematoxylin and eosin staining, enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction assays.

KEY FINDINGS

It was shown that Gl-PS stimulated IEC-6 cell proliferation and migration significantly in a dose-dependent manner; 10 µg/ml Gl-PS improved the morphology of differentiation in IEC-6 cells. Inefficacy in expression of TGF-β in IEC-6 cells indicated a possible TGF-β independent action of Gl-PS. However, Gl-PS increased ODC mRNA and c-Myc mRNA expression in a dose-dependent manner, indicating, at least partially possible involvement of ODC and c-Myc gene expression in improvement of intestinal wound healing.

CONCLUSIONS

These results suggest the potential usefulness of Gl-PS to cure intestinal disorders characterized by injury and ineffective repair of the intestinal mucosa.