ETHNOPHARMACOLOGICAL RELEVANCE: According to the Chinese Pharmacopoeia, the seeds of Vaccaria segetalis, a traditional medicinal herb, can be used for treating urinary diseases. The polysaccharides extract from V. segetalis seeds (VSP) has been shown to prevent urinary tract infections (UTIs).
AIM OF THE STUDY: Investigate the effects of VSP on treating kidney infection induced by uropathogenic Escherichia coli (UPEC) and the underlying mechanisms.
MATERIALS AND METHODS: Both in vivo and in vitro infection models were established with the UPEC strain CFT073. After oral administration of VSP, the levels of bacterial load, cathelicidin (CRAMP), Toll-like receptors (TLRs) in the kidney were evaluated. The expression of cathelicidin (LL-37) in human renal cell carcinoma cell line (A498) was tested after the treatment of VSP.
RESULTS: In the kidneys of infection models, high-titer bacteria was detected. In the kidney of rat model, the expression of CRAMP was down-regulated, no significant change was observed in the levels of TLRs. After oral administration of VSP, the bacterial load was significantly decreased in rat and mouse models, and the levels of CRAMP and TLRs were significantly up-regulated in rat model. In vitro, the expression of LL-37 was significantly inhibited by CFT073. VSP up-regulated the expression of LL-37 in A498 cells.
CONCLUSIONS: The up-regulation of cathelicidin expression may contribute to the therapeutic effects of VSP on kidney infection.