BackgroundThe young shoots of Rubus idaeus are traditionally used as a herbal remedy in common cold, fever and flu-like infections yet there is no research concerning this plant material. The aim of the study was to evaluate the chemical composition and biological properties of raspberry shoots from 11 cultivar varieties.MethodsThe methanol extracts were subjected to chromatographic analysis using HPLC-DAD-ESI-MS, and two-dimensional ‘comprehensive’ LCxLC techniques. The biological activity of the shoot extract from the ‘Willamette’ cultivar variety was evaluated. Antioxidant activity was tested using DPPH and phosphomolybdenum assay. Antimicrobial activity was estimated towards 15 strains of human pathogenic bacteria using broth microdilution method. Cytotoxic activity was tested using MTT cell viability assay.ResultsThe dominating compounds identified in the shoots of R. idaeus were ellagic acid (26.1 - 106.8 mg/100 g) and sanguiin H-6 (139.2 - 633.1 mg/100 g). The best separation of compounds present in the analysed polyphenol complex, was achieved by ‘comprehensive’ LCxLC method using Nucleodur Sphinx RP column in the first dimension and Chromolith Performance column in the second dimension. The shoot extract was found to be a strong antioxidant (EC50 19.4 μg/ml, AAE 427.94 mg/g) and displayed the strongest bactericidal properties towards Corynebacterium diphtheriae. The extract revealed higher cytotoxic activity towards the HL-60 cells (IC50 110 μg/ml) than HeLa (IC50 300 μg/ml).ConclusionsThe shoots of R. idaeus stand out as a valuable source of sanguiin H-6 and ellagic acid and possess a number of biological properties including antioxidative, antimicrobial and cytotoxic.

Raspberries, derived from different cultivar varieties, are a popular ingredient of everyday diet, and their biological activity is a point of interest for researchers. The ethanol-water extracts from four varieties of red (Rubus idaeus'Ljulin', 'Veten', 'Poranna Rosa') and black (Rubus occidentalis'Litacz') raspberries were evaluated in the range of their antimicrobial properties as well as phenolic content - sanguiin H-6, free ellagic acid and anthocyanins. The antimicrobial assay was performed with the use of fifteen strains of bacteria, both Gram-negative and Gram-positive. The antimicrobial activity of the extracts varied and depended on the analysed strain of bacteria and cultivar variety, with the exception of Helicobacter pylori, towards which the extracts displayed the same growth inhibiting activity. Two human pathogens Corynebacterium diphtheriae and Moraxella catarrhalis proved to be the most sensitive to raspberry extracts. Contrary to the extracts, sanguiin H-6 and ellagic acid were only active against eight and nine bacterial strains, respectively. The determined MIC and MBC values of both compounds were several times lower than the tested extracts. The highest sensitivity of Corynebacterium diphtheriae to extracts from both black and red raspberries may be due to its sensitivity to sanguiin H-6 and ellagic acid.

No abstract

No abstract