Cranberry Juice and Combinations of Its Organic Acids Are Effective against Experimental Urinary Tract Infection

Abstract

The antibacterial effect of cranberry juice and the organic acids therein on infection by uropathogenic Escherichia coli was studied in an experimental mouse model of urinary tract infection (UTI). Reduced bacterial counts were found in the bladder (P < 0.01) of mice drinking fresh cranberry juice. Commercially available cranberry juice cocktail also significantly reduced (P < 0.01) bacterial populations in the bladder, as did the hydrophilic fraction of cranberry juice (P < 0.05). Quinic, malic, shikimic, and citric acid, the preponderant organic acids in cranberry juice, were tested in combination and individually. The four organic acids also decreased bacterial levels in the bladder when administered together (P < 0.001), and so did the combination of malic plus citric acid (P < 0.01) and malic plus quinic acid (P < 0.05). The other tested combinations of the organic acids, and the acids administered singly, did not have any effect in the UTI model. Apparently, the antibacterial effect of the organic acids from cranberry juice on UTI can be obtained by administering a combination of malic acid and either citric or quinic acid. This study show for the first time that cranberry juice reduce E. coli colonization of the bladder in an experimental mouse model of urinary tract infection and that the organic acids are active agents.

Influence of Cranberry Extract on Tamm-Horsfall Protein in Human Urine and its Antiadhesive Activity Against Uropathogenic Escherichia coli

“…Additionally, cranberry extracts are highly complex mixtures from various classes of natural products, including carbohydrates, polysaccharides, organic acids, flavonoids, oligomeric PACs, terpens, and many others. As shown in previous studies from different groups PAC metabolites [11,16], anthocyanidins [17], flavonoids [18], and short-chain organic acids [19] might influence under in vitro conditions the bacterial adhesion. These in vitro data in most cases do not reflect the real pharmacokinetic properties of these compounds and are in part contradictory in the relevant literature ( [11] vs. [16]).…”

Antibacterial Activity of Some Flavonoids and Organic Acids Widely Distributed in Plants

“…Results of these studies demonstrated that salicylic acid was practically inactive against various bacterial strains, including B. subtilis ATCC 6633, E. faecalis ATCC 29212, S. aureus, MSSA ATCC 25923, and S. pneumoniae ATCC 33400 (MIC = 32,000 µg/mL). The antibacterial properties are relatively well known for small aliphatic molecules tested by us: citric, malic, and quinic acids [91][92][93]. Investigations concerning the effect of quinic acid on cellular functions of S. aureus demonstrated that this organic acid could significantly decrease the intracellular pH and ATP concentration, and also reduce the DNA content [93].…”

“…In turn, Gao et al [85] demonstrated no clear activity of citric and malic acids against E. coli (MIC = 1667 and 2000 µg/mL, respectively) B. subtilis (MIC = 2000 µg/mL), and S. suis (MIC = 8000 and 6667 µg/mL). However, Jensen et al [92] exhibited that cranberry juice and its main compounds (citric, malic, quinic, and shikimic acids) reduce E. coli colonization of the bladder. These organic acids decreased bacterial levels when they were administered together or in a combination of malic acid and citric or quinic ones.…”

Oligosaccharides and Complex Carbohydrates: A New Paradigm for Cranberry Bioactivity

“…Multiple compounds found in cranberry are known to have a variety of effects on different microbes. For example, organic acids, polyphenols, flavonoids, and complex carbohydrates are all known to have different effects on microbial growth, adhesion, and biofilm formation [3,7,99,193,[202][203][204][205]212,[294][295][296][297][298][299]. These effects would combine in different ways to influence overall microbiome profiles in vivo.…”