# Novel Insights on Plant Extracts to Prevent and Treat Recurrent Urinary Tract Infections
## 6 Plants Commonly Used in the Treatment of rUTI
### Promising Medicinal Plants to Treat rUTI
#### 6.2.2 A. melanocarpa  
Sometimes known as scores, chokeberry fruits are members of the _Rosaceae family's Aronia genus. A. melanocarpa_ (Michx.) Elliott--black chokeberry and _A. arbutifolia_ L.--red chokeberry are the two shrubs species utilized as fruits in the genus (red scab) [58]. The fruit of _A. melanocarpa_ (Figure 3) is known for its high concentration of bioactive compounds, such as polyphenols with significant antioxidant and antimicrobial effects, which have been studied intensively for the last 15 years [59]. The proanthocyanidin concentration of _A. melanocarpa_ is four times higher than in cranberry, and aronia berries contain a higher dose of quinic acid; both compounds help fight and prevent UTI [60]. Moreover, 100 g of raw cranberries were scaled at 9584 on the USDA ORAC (oxygen radical absorbance capacity) value scale, with the highest antioxidant capacity from common fruits, while aronia berry was 16,862 [61]. Figure 3: The fruit of _A. melanocarpa_ growing in Ionáseni village, Värfu Cämpului, Botosani county, Romania. The mechanism of action for anthocyanins from _A. melanogaster_ proved that at a minimum inhibitory concentration (MIC) of 0.625 mg/mL and minimum bactericidal concentration of 1.25 mg/mL, anthocyanins compromise the integrity of the _E. coli_ cell wall and membrane, bind directly to the bacterial DNA, and interfere with protein homeostasis [62]. Epicatechin, a proanthocyanidin from _Aronia_ extracts, has been involved in the biofilm formation effect in the case of unpathogenic _E. coli_ CFT073 (ATCC 700928). It supposes that the active substance interferes with quorum-sensing chemotaxis/or mobility genes [63]. Bacteria in a biofilm are often responsible for recurrence and antibiotic treatment failure. Therefore, finding new plants rich in bioactive molecules with anti-biofilm activity, such as epicatechin from _A. melanogaster_, ellagic acid from _P. grantum_, and unsolic acid from cranberry, is a good non-antitoxic inhibition strategy with a reduced potential for resistance development. The results of the antibacterial activities of black chokeberry fruit extract are mixed. In a recent study, the leaf aqueous extract had a bacteriostatic effect against _E. coli_ and _L. monocytogenes_, decreasing the growth rate and extending the lag phase [64]. An HPLC analysis showed that _Aronia_ extract contained 15 phenolic compounds and 11 flavonoids, mainly flavonoids and hydroxycinamic acid. The total concentration of phenolic acids (114.66 mg/mL) was higher than that of flavonoids (93.40 mg/mL). However, no clear relationship was found between the influence of the aronia extracts and whether the tested bacteria belonged to the Gram-positive or Gram-negative groups. In another study, a common inhibition effect was noticed for 20 \(\upmu\)m of black chokeberry leaf extract that reduced the growth of the tested _E. coli_ strain by 23% [64, 65]. Similarly, it has been shown that aqueous and ethanolic extracts of fresh, dried, or frozen fruits have efficacy against _Bacillus cereus_, _S. aureus_, and _Pseudomonas aeruginosa_ but did not influence _E. coli_ 332 [66]. In a study, _E. coli_ strains were resistant to extracts from leaves, berries, and stems obtained by subcritical water extraction [66, 67]. These contradictory results could be explained by differences in the extract preparation method and the tested _E. coli_ strains. Anthocyanidin-rich extracts obtained as lyophilized powders from mature fruits of _A. melanogaster_ L., cultivated in the ecological environment in the Eastern Carpathians in Romania, were used to test the synergism-based antibiotic treatment on pathogens from the urinary tract [68]. The extract contained anthocyanins and epicatechin units, and the extraction method had an essential impact on the quantity of each component of the plant extract.