Chemical composition and in vitro antimicrobial and cytotoxic activities of plum (Prunus domestica L.) wine

© 2016 The Institute of Brewing & Distilling. A moderate intake of wine is associated with a positive impact on human health owing to the effects of important biologically active components present in the wine in large amounts. The aim of this study was to examine the chemical composition and to assess antimicrobial and cytotoxic activities of fruit wines produced from three plum varieties (Čačanska rana, Čačanska lepotica and Požegača) commonly grown in Serbia as an approach to assess the quality and acceptability of these wines as a functional food. Furthermore, the activity of a series of control samples was assessed in order to determine components from the wine that are responsible for its functional properties. The plum wines produced showed considerable antimicrobial activity against six bacterial and two yeast strains used in this study. In addition to antimicrobial activity, the plum wines showed a significant cytotoxic effect (IC50<50μgmL-1) on the growth of three tested cancer cell lines (Hep2c, RD and L2OB). Regarding the determined activities, Čačanska rana plum wine achieved the best results. The results indicated that the antimicrobial activity of the plum wines was, in large part, based on the effects of the total acids and the pH value, while the contribution of ethanol and the content of the phenolic compounds were not significant. Similar conclusions were drawn regarding the cytotoxic activity of this fruit wine. The results can be seen as a contribution to the global acceptance of fruit wines as a functional food, with the accent placed on moderate consumption. An important advantage of fruit wines (in particular plum wine), compared with traditional grape wine, is their lower alcohol content

Antifungal activity of quinhydrone against saccharomyces cerevisiae

Quinhydrone (QH) is a redox active charge transfer complex commonly used as a redox standard. Information on quinhydrone generation in plants is scarce and its physiological role is still unclear. Recently we have showed that excess zinc may induce oxidative stress through QH accumulation in the cell wall and stabilization of phenoxyl radicals [1]. The aim of our research was to investigate the antifungal activity of quinhydrone against yeast Saccharomyces cerevisiae (112, Hefebank Weihenstephan). Saccharomyces cerevisiae was grown on the Sabouraud maltose broth (HiMedia, Mumbai, India) in the presence of different concentrations of QH ranging from 75 mu M to 500 mu M. Concentrations of QH greater than 300 mu M had complete inhibitory effect on yeast growth, while lower concentrations (up to 200 mu M) did not affect the growth. QH had a significant impact on antioxidative defense enzymatic systems, indicated by the changes in the activity in catalase (CAT) and superoxide dismutase (SOD). CAT activities increased by 43% (150 mu M QH) and SOD activities by 122% and 60% at 150 mu M and 220 mu M QH respectively. However, abrupt inhibition of both enzymes was observed at concentrations higher than 220 mu M QH (>= 70%), to be almost completely diminished at 280 mu M QH. High molecular weight genomic DNA without any laddering or smearing was detected in both control and QH treated yeast cells, indicating the absence of apoptosis

Betalains: Natural plant pigments with potential application in functional foods

Betalains are plant derived natural pigments that are presently gaining popularity for use as natural colorants in the food industry. The growing interest of consumers in the aesthetic, nutritional and safety aspects of food has increased the demand for natural pigments such as betalains to be used as alternative colorants in food products. Although betalains from red beetroot are one of the most widely used food colorant, betalains are not as well studied as compared to other natural pigments such as anthocyanins, carotenoids or chlorophylls. This paper reviews the pharmacological properties, such as antioxidant, anti-cancer, anti-lipidemic and antimicrobial activity of betalains derived from sources such as red beetroot, amaranth, prickly pear and red pitahaya, for potential application as functional foods

Comparative Study of Betacyanin Profile and Antimicrobial Activity of Red Pitahaya (Hylocereus polyrhizus) and Red Spinach (Amaranthus dubius)

Betacyanins are reddish to violet pigments that can be found in red pitahaya (Hylocereus polyrhizus) and red spinach (Amaranthus dubius). This study investigated the impact of sub-fractionation (solvent partitioning) on betacyanin content in both plants. Characterization of betacyanins and evaluation of their antimicrobial activities were also carried out. Betanin was found in both plants. In addition, isobetanin, phyllocactin and hylocerenin were found in red pitahaya whereas amaranthine and decarboxy-amaranthine were found in red spinach. Sub-fractionated red pitahaya and red spinach had 23.5 and 121.5 % more betacyanin content, respectively, than those without sub-fractionation. Sub-fractionation increased the betanin and decarboxy-amaranthine content in red pitahaya and red spinach, respectively. The betacyanin fraction from red spinach (minimum inhibitory concentration [MIC] values: 0.78–3.13 mg/mL) demonstrated a better antimicrobial activity profile than that of red pitahaya (MIC values: 3.13–6.25 mg/mL) against nine Gram-positive bacterial strains. Similarly, the red spinach fraction (MIC values: 1.56–3.13 mg/mL) was more active than the red pitahaya fraction (MIC values: 3.13–6.25 mg/mL) against five Gram-negative bacterial strains. This could be because of a higher amount of betacyanin, particularly amaranthine in the red spinach

Antimicrobial potential of wild edible herbaceous species

Natural products, either as pure compounds or as standardized extracts, provide unlimited opportunities to control microbial growth, owing to their chemical composition and diversity. Many herb and spice extracts possess antimicrobial activity against a range of bacteria, yeast, and moulds. Because of their antimicrobial properties, they could be very useful, either as food preservatives or as natural biopesticides. In particular, extracts from wild edible herbaceous species are rich in phenolic compounds. A wide variety of phenolics derived from herbs and spices possesses potent biological activities contributing to their effect against spoilage microorganisms. Many studies have pointed out the antimicrobial properties of certain classes of phenolic compounds, such as hydroxybenzoic, coumaric, and caffeic acid derivatives, flavonoids and coumarins, catechin, epicatechin, proanthocyanidins, and tannins. Moreover, some authors studied the relationship between molecular structure and antimicrobial activity of some phenolic compounds. The antimicrobial activity of polyphenols is principally due to inhibition of some important cellular functions (nucleic acid synthesis, cytoplasmatic membrane functionality, etc.) and to disruption of membrane integrity with consequent leakage of cellular contents. This chapter reviews the most important phenol-rich wild edible herbaceous species known within the Mediterranean area, highlighting the relationship between phenolic composition and antimicrobial activity of their extracts. Moreover, the problem of standardization and safety of plant extracts is analyzed in the light of the latest literature