Cistus x incanus L. extract as a complex polyphenolic blend with retained anti-adhesive and anti-inflammatory properties in a model of E. coli-induced UTI following simulated digestion.

ETHNOPHARMACOLOGICAL RELEVANCE: Cistus x incanus L. is a Mediterranean plant traditionally used to treat infective conditions, including urinary tract infections (UTI). However, experimental validation against uropathogenic Escherichia coli (UPEC) is limited.

AIM OF THE STUDY: To investigate the antibacterial and anti-inflammatory effects of a hydroalcoholic extract of aerial parts (CE) in an E. coli-induced UTI model, evaluating stability and efficacy after intestinal digestion.

MATERIALS AND

METHODS

T24 bladder epithelial cells were infected with UPEC CFT073 and treated with CE before and after simulated intestinal digestion (CEd). IL-6 release, bacterial growth, and adhesion were evaluated. Polyphenol content and stability were analyzed using colorimetric assays and LC-MS/MS. A methanol-insoluble fraction (IF) of CE was also tested.

RESULTS

CE inhibited IL-6 release with an IC50 of 16.05 μg/mL during infection and 0.43 μg/mL upon TNF-α stimulation; IL-8 was also reduced. CE markedly decreased UPEC adhesion to T24 cells (-79 % at 200 μg/mL). After digestion, CEd retained anti-inflammatory activity (IC50 for IL-6: 19.05 μg/mL during infection; 1.69 μg/mL with TNF-α). Flavonols remained relatively stable post-digestion, while catechins and procyanidins decreased. IF, rich in glycosidic flavonols and tannins, preserved its anti-inflammatory and antibacterial activity before and after digestion.

CONCLUSIONS

These findings support, for the first time, the traditional use of Cistus x incanus in UTI, highlighting its ethnopharmacological relevance in the treatment of urinary infections. The mechanism of action, which includes anti-inflammatory and anti-adhesive activities of the extracts, has been investigated. The efficacy was observed at micromolar concentrations, which are supposed to be reached in vivo consuming Cistus x incanus food supplements. These findings lay groundwork for preclinical UTI models. Moreover, the outcomes in the present study warrant clinical investigations to consolidate our findings.