Planta Med 2013; 79 - PI88
DOI: 10.1055/s-0033-1352177

Extract of maydis stigma (Zea mays L.) inhibits the adhesion of uropathogenic Escherichia coli (UPEC) to human bladder cells

N Rafsanjany 1, A Hensel 1
  • 1University of Münster, Institute of Pharmaceutical Biology and Phytochemistry, 48149 Münster, Germany

The stigma/style of the female flower of Zea mays L. (Poaceae) has been used traditionally as a therapeutic remedy for various ailments such as cystitis, urethritis, nephritis, nocturnal enuresis, prostatitis, gout, and kidney stones in form of decoctions or aqueous-alcoholic extracts for per oral use. Due to literature the stigmata contain proteins, vitamins, carbohydrates, fixed and volatile oils, phytosterols, alkaloids, saponins, tannins, and flavonoids. Therefore maydis stigma was screened on potential antiadhesive activity against UPEC by an in vitro assay with a positive outcome (IC50 1041 µg/mL) [1]. The present study was carried out to determine responsible compounds from maydis stigma against UPEC.

1 kg of dried plant material (Hungarian origin) was extracted by Soxhlet with petroleum benzine for 6h. The residue was air dried at room temperature for 12h and then reextracted with 10 L EtOH/water (1:1) by ultraturrax. The extract was fractionated by gel permeation chromatography on Sephadex LH-20. The received 22 fractions were investigated on potential antiadhesive activity with FITC-labeled UPEC on T24 bladder cells by flow cytometric evaluation. Fraction I (approx. IC50 1218 µg/mL) and XI (approx. IC50 1120 µg/mL) showed strong antiadhesive activity. Due to agar diffusion assay and MTT assays direct cytotoxicity against UPEC and T24 cells can be excluded. From fraction I a Dragendorff-positive compound was isolated by extraction with CH2Cl2 from the alkaline solution. The respective steroidal alkaloid (C27H41NO2 after ESI MS, λmax. 210nm) showed strong antiadhesive activity and has to be regarded as the main active principle of the herbal material.

Reference:

[1] Rafsanjany N, Lechtenberg M, Petereit F, Hensel A (2013) Antiadhesion as a functional concept for protection against uropathogenic E. coli: in vitro studies with traditionally used herbal extracts as antiadhesive entities against uncomplicated urinary tract infections. J. Ethnopharm. 145, 591 – 597