Antimicrobial activity of tea polyphenols

Epilobium species are used in Romanian folk medicine as tinctures, tea, or tablets for ameliorating the symptoms of benign prostate hyperplasia (BPH), but scientific-based evidence is scarce for this species or other endemic plants of the same genus. Therefore, the aims of this research were to evaluate the phytochemical profile of five endemic Epilobium species ( E. hirsutum L., E. parviflorum Schreb., E. palustre L. E. dodonaei Vill., and E. angustifolium L.) and to assess their in vitro biological activity...

To reduce thermal degradation of tea polyphenols (TP) in final active packaging materials, poly(butylene adipate-co-terephthalate) (PBAT), starch, plasticizer, and TP were directly synthesized into masterbatches by one-pot method in this study without pre-dispersion, and then blown into active films. TP interacted with starch through hydrogen bonds, with little interaction with PBAT. Barrier properties were improved by incorporating TP into the films, whereas mechanical properties slightly decreased. Blending starch into PBAT greatly accelerated the degradation of the film...

Fifty isolates of Vibrio parahaemolyticus were tested for pathogenicity, biofilm formation, motility, and antibiotic resistance. Antimicrobial activity of chitooligosaccharide (COS)-tea polyphenol conjugates against all isolates was also studied. Forty-three isolates were randomly selected from 520 isolates from Asian green mussel ( Perna viridis ) grown on CHROMagarTM Vibrio agar plate. Six isolates were acquired from stool specimens of diarrhea patients. One laboratory strain was V. parahaemolyticus PSU.SCB...

Trimethyltin chloride (TMT) is an organotin-based contaminant present in the water environment that poses a great threat to aquatic organisms and humans. The liver is the detoxification organ of the body and TMT exposure accumulates in the liver. Tea polyphenol (TP) is a natural antioxidant extracted from tea leaves and has been widely used as a food and feed additive. To investigate the mechanism of toxicity caused by TMT exposure on grass carp hepatocytes (L8824 cells) and the mitigating effect of TP, we established a hepatocyte model of TMT toxicity and/or TP treatment...

In recent years, changing lifestyles and food consumption patterns have driven demands for high-quality, ready-to-eat food products that are fresh, clean, minimally processed, and have extended shelf lives. This demand sparked research into the creation of novel tools and ingredients for modern packaging systems. The use of phenolic-compound-based active-packaging and edible films/coatings with antimicrobial and antioxidant activities is an innovative approach that has gained widespread attention worldwide...

The present work investigated the effects of high-pressure processing (200 and 400 MPa, 5 min) combined with chitosan-tea polyphenol (1.5% and 0.5% [w/v], respectively) coating to improve the quality and stability of shrimp ( Penaeus monodon ) during 28 days of storage. The chemical (pH, TVB-N, TBARS), microbiological, textural, chromatic characteristics, protein oxidation, and endogenous enzyme activities of shrimps were regularly evaluated. Results showed that the combination treatment exerted a better intense antimicrobial effect, stabilized shrimp's freshness, and resulted in lower pH and TVB-N than the control sample...

Kombucha culture (named SCOBY-Symbiotic Culture of Bacteria and Yeasts) and milk kefir grains represent multiple consortia of wild microorganisms that include lactic acid bacteria, acetic acid bacteria and yeasts with valuable functional properties. Their fermentative potential provides a wide range of derivate metabiotics (prebiotics, probiotics, postbiotics and paraprobiotics) with valuable in vitro and in vivo benefits. This study targeted the evaluation of the functionality of a co-culture of SCOBY-based membranes and milk kefir grains, used as freeze-dried starter cultures, for the fermentation of a newly formulated medium based on black tea infusion, supplemented with bovine colostrum and sugar, in order to produce bioactive compounds with functional properties...

For thousands of years, caries, periodontitis and mucosal diseases, which are closely related to oral microorganisms, have always affected human health and quality of life. These complex microbiota present in different parts of the mouth can cause chronic infections in the oral cavity under certain conditions, some of which can also lead to acute and systemic diseases. With the mutation of related microorganisms and the continuous emergence of drug-resistant strains, in order to prevent and treat related diseases, in addition to the innovation of diagnosis and treatment technology, the development of new antimicrobial drugs is also important...

Streptococcus suis ( S. suis ) is a highly virulent zoonotic pathogen and causes severe economic losses to the swine industry worldwide. Public health security is also threatened by the rapidly growing antimicrobial resistance in S. suis . Therefore, there is an urgent need to develop new and safe antibacterial alternatives against S. suis . The green tea polyphenol epigallocatechin gallate (EGCG) with a number of potential health benefits is known for its antibacterial effect; however, the mechanism of its bactericidal action remains unclear...

The use of nanoparticles in medicine, nanomedicine, is very important to diagnose and treat diseases; among the various metallic nanoparticles, silver nanoparticles (AgNPs) are very popular due to their physical, chemical, and biological properties, encompassing a range of activities such as antiviral, antifungal, anti-inflammatory, and anticancer activities. In this study, the synthesis of AgNPs was conducted by the use of a nontoxic, ecofriendly method. Green tea (GT) leaf extract was used as a reducing agent to convert silver ions into free AgNPs...

AIMS: To investigate the antibacterial effects of tea theaflavins and catechins against Bacillus coagulans and the underlying mechanism of antibacterial action. METHODS AND RESULTS: Bactericidal activities of theaflavin and its analogs were evaluated and compared with that of epigallocatechin gallate. Theaflavin derivatives exhibited high bactericidal activity at 50 μmol L-1 , whereas epigallocatechin gallate did not, even at 500 μmol L-1 . Further, we investigated the adsorption of theaflavins to model phospholipid membranes and corresponding effects on membrane fluidity to reveal their effects on the B...

Kombucha is a beverage made by fermenting sweetened tea with a symbiotic culture of yeast and bacteria. Literature data indicate that the kombucha beverage shows many health-promoting properties such as detoxification, chemo-preventive, antioxidant, antimicrobial, antifungal, and general strengthening. The research conducted focuses on the analysis of polyphenolic compounds formed in the fermentation process using ultra-efficient liquid chromatography, as well as on checking the antimicrobial properties of kombucha against pathogenic bacteria and yeasts found in food...

BACKGROUND: A wide range of natural and synthetic compounds bind and inhibit ATP synthase. Dietary polyphenols found in fruits, vegetables, and spices such as tea, olives, grapes, cantaloupes, garlic, and pomegranate possess antimicrobial activities. Dietary pomegranate polyphenols (DPPs) have been shown to exhibit anticancer, antioxidant, and antimicrobial properties. In the current study we are exploring the connection between antimicrobial properties of DPPs and the inhibition of microbial ATP synthase...

An imperative processing way to produce 3D printed structures with enhanced multifunctional properties is printing inks in the form of a gel-like colloidal emulsion. The surface-modified microcrystalline cellulose (MCC) is an excipient of outstanding merit as a particulate emulsifier to manufacture a stable Pickering emulsion gel. The tuning of the MCC structure by cationic antimicrobial compounds, such as ε-polylysine (ε-PL), can offer a surface activity with an antimicrobial effect. However, the MCC/ε-PL lacks the appropriate emulsifying ability due to the development of electrostatic complexes...

The spread of multidrug-resistant (MDR) Vibrio cholerae necessitates the development of novel prevention and treatment strategies. This study aims to evaluate the in vitro antibacterial activity of green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) against MDR V. cholerae . First, MIC and MBC values were evaluated by broth microdilution techniques against 45 V. cholerae strains. The checkerboard assay was then used to determine the synergistic effect of EGCG and tetracycline. The pharmaceutical mode of action of EGCG was clarified by time-killing kinetics and membrane disruption assay...

Kombucha, originated in China 2000  years ago, is a sour and sweet-tasted drink, prepared traditionally through fermentation of black tea. During the fermentation of kombucha, consisting of mainly acidic compounds, microorganisms, and a tiny amount of alcohol, a biofilm called SCOBY forms. The bacteria in kombucha has been generally identified as Acetobacteraceae. Kombucha is a noteworthy source of B complex vitamins, polyphenols, and organic acids (mainly acetic acid). Nowadays, kombucha is tended to be prepared with some other plant species, which, therefore, lead to variations in its composition...

Flavonoids are a group of natural polyphenol substances abundant in vegetables, fruits, grains, and tea. As plant secondary metabolites, flavonoids play essential roles in many biological processes and responses to environmental factors in plants. Flavonoids are common in human diets and have antioxidant effects as well as other bioactivities (e.g., antimicrobial and anti-inflammatory properties), which reduce the risk of disease. Flavonoid bioactivity depends on structural substitution patterns in their C6-C3-C6 rings...

Vibrio parahaemolyticus (V. parahaemolyticus) is a common marine foodborne pathogen that causes gastroenteritis. With the long-term use of antibiotics, many bacteria become resistant strains, therefore, developing antibiotic-free antimicrobial strategies is urgent. Epigallocatechin gallate (EGCG) as the abundant constituent of polyphenols in tea extract has broad-spectrum antibacterial activity and non-toxicity. Here, we took advantage of EGCG to evaluate its inhibition effect on the growth of V. parahaemolyticus 17802 and the biofilm formation, and explore its antibacterial mechanism...

Pu-erh tea is post-fermented sun-dried tea leaves of Camellia sinensis (Linn.) var. assamica (Masters) Kitamura plant, native to Yunnan, China. Pu-erh tea is a highly prized commodity with unique aroma and taste and multiple health effects. This review overviews the chemical constituents, tentative bioactive compounds and their mechanisms responsible for bioactivities of Pu-erh tea. The bioactivities include antioxidative, antimutagenic, antimicrobial, laxative and neuroprotective activities, and controlling or preventing hypercholesterolemia, hyperglycemia, obesity, diabetes, osteoporosis and Alzheimer's disease...

Green tea has protective effects against various diseases such as malignancies, cardiovascular and metabolic disorders. Green tea has been suggested to promote periodontal health by reducing inflammation, preventing the resorption of bones and restricting the growth of certain periodontal-related bacteria. Green tea has antioxidant, carcinogenic, antimicrobial and non-inflammatory properties. This traditional drink is also used to treat systemic chronic diseases, including carcinoma. Recent studies have shown that host immuno-inflammatory reactions, in addition to microbial activity, are more likely to destroy oral tissues...