Kombucha tea is a refreshing beverage that is produced from the fermentation of tea leaves. In this study, kombucha tea was prepared using 1% green tea, oolong tea, and black tea, and 10% sucrose with acetic acid bacteria and yeast. The pH values of the kombucha tea were found to be in a range of 2.70–2.94 at 15 days of fermentation. The lowest pH value of 2.70 was recorded in the kombucha prepared from black tea. The total acidity of kombucha prepared from black tea was the highest by 16.75 g/L and it was still maintained after heat treatment by boiling and after autoclaved. Six organic acids: glucuronic, gluconic, D-saccharic acid 1,4-lactone, ascorbic, acetic, and succinic acid in kombucha tea were detected by HPLC with the optimization for organic acids detection using isocratic elution buffer with C18 conventional column. The highest level of organic acid was gluconic acid. Kombucha prepared from green tea revealed the highest phenolic content and antioxidation against DPPH radicals by 1.248 and 2.642 mg gallic acid/mL kombucha, respectively. Moreover, pathogenic enteric bacteria: Escherichia coli. E. coli O157:H7. Shigella dysenteriae, Salmonella Typhi, and Vibrio cholera were inhibited by kombucha and heat-denatured kombucha with diameter of the inhibition zones ranged from 15.0 ± 0.0–25.0 ± 0.0 mm. In addition, kombucha prepared from green tea and black tea demonstrated toxicity on Caco-2 colorectal cancer cells. Therefore, kombucha tea could be considered as a potential source of the antioxidation, inhibition of pathogenic enteric bacteria, and toxicity on colorectal cancer cells.

Abstract. Mouth-dissolving fibers with antibacterial activity for the oral cavity were prepared by an electrospinning technique. Propolis extract was used as an active ingredient and polyvinylpyrrolidone (PVP) K90 as the polymer matrix. The morphology and diameter of the fibers were characterized by scanning electron microscopy. Antibacterial activity against Streptococcus mutans and the inhibition of S. mutans adhesion on a smooth glass surface during the biofilm formation were tested. Propolis, 5% (w/ v), was combined with a PVP K90 solution, 8% (w/v), with or without Tween 80 including flavor additives and electrospun with an applied voltage of 15 kV. Uniform and smooth fibers of propolis-PVP K90 were obtained. The results showed that electrospun fibers with propolis extract can dissolve and release the propolis in water. Propolis-PVP electrospun fibers showed better antibacterial activity by reduction of bacteria adhesion on a smooth glass surface when compared to some commercial mouthwash products. These results indicated the potential of electrospun fibers to be used as mouth-dissolving fibers for effective antibacterial activity in the oral cavity.

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In this study, an extract from the flower buds of Eugenia caryophyllus (Spreng.) Bullock & S. G. Harrison and the essential oil, eugenol, were evaluated for their anti-herpes simplex virus properties on standard HSV-1(F), standard HSV-2(G) and ten HSV isolates. The plaque reduction assay showed that HSV-1(F), HSV-2(G), two HSV-1 isolates (2, 30) and four HSV-2 isolates (1, 2, 3, 21) were inhibited by E. caryophyllus. Only HSV-1 isolates 1 and 30 were inhibited by eugenol. Thus, strains or isolates of viruses may affect the range of inhibition. Moreover, particles of HSV standard strains were directly inactivated by E. caryophyllus and eugenol. The total virus yield of HSV standard strains and isolates at 30 h also declined after treatment with E. caryophyllus and eugenol. The E. caryophyllus extract exerted higher antiviral replication on HSV-2(G) than on HSV-1(F). The inhibition of the viral yield of HSV-1 isolates was higher than standard HSV-1(F) and standard HSV-2(G) was also inhibited more than most of the HSV-2 isolates. The anti-HSV activity of eugenol against HSV-1(F) and HSV isolates was stronger than with the E. caryophyllus crude extract. However, the percentage inhibition was more pronounced on HSV-1(F) than on HSV-2(G). Moreover, HSV-1(1) and HSV-2(1, 32) could not replicate when eugenol was included in the assay.

BackgroundHoney is a natural product obtained from the nectar that is collected from flowers by bees. It has several properties, including those of being food and supplementary diet, and it can be used in cosmetic products. Honey imparts pharmaceutical properties since it has antibacterial and antioxidant activities. The antibacterial and antioxidant activities of Thai honey were investigated in this study.ResultsThe honey from longan flower (source No. 1) gave the highest activity on MRSA when compared to the other types of honey, with a minimum inhibitory concentration of 12.5% (v/v) and minimum bactericidal concentration of 25% (v/v).Moreover, it was found that MRSA isolate 49 and S. aureus were completely inhibited by the 50% (v/v) longan honey (source No. 1) at 8 and 20 hours of treatment, respectively. Furthermore, it was observed that the honey from coffee pollen (source No. 4) showed the highest phenolic and flavonoid compounds by 734.76 mg gallic/kg of honey and 178.31 mg quercetin/kg of honey, respectively. The antioxidant activity of the honey obtained from coffee pollen was also found to be the highest, when investigated using FRAP and DPPH assay, with 1781.77 mg FeSO4•7H2O/kg of honey and 86.20 mg gallic/kg of honey, respectively. Additionally, inhibition of tyrosinase enzyme was found that honey from coffee flower showed highest inhibition by 63.46%.ConclusionsHoney demonstrates tremendous potential as a useful source that provides anti-free radicals, anti-tyrosinase and anti-bacterial activity against pathogenic bacteria causing skin diseases.