Phenolic composition and antioxidant, antimicrobial and cytotoxic properties of hop (Humulus lupulus L.) Seeds

Abstract

Hop (Humulus lupulus L.) is a perennial climbing plant cultivated for commercial use, mainly in brewing industry, since the female inflorescences (cones) contain lupulin glands that confer the characteristic bitterness, aroma and flavour to beer. However, the bioactive potential of the seeds found in these cones remains unexplored. In this study, the phenolic composition of hop seeds was analysed by LC-DAD-ESI/MS n and its antioxidant, cytotoxic and antimicrobial activities were screened against oxidizable substrates, human tumour and non-tumour cell lines, and different bacteria and fungi, respectively. (+)-Catechin and (-)-epicatechin were identified in the seeds, totalizing 17.6 ± 0.7 mg/g extract. The seed extract showed antioxidant activity mainly through the formation inhibition of thiobarbituric acid reactive substances (TBARS), and had cytotoxic effects against MCF-7 (breast adenocarcinoma), NCI-H460 (non-small cell lung cancer), HeLa (cervical carcinoma), and HepG2 (hepatocellular carcinoma) tumour cells, but no toxicity towards the normal PLP2 cell line was observed. The extract showed remarkable antimicrobial properties, being better than the positive controls against almost all tested bacteria and fungi of the genus Penicillium. These results highlight the potential of hop seeds as a source of functional ingredients with applications in the food and pharmaceutical sectors.

Multiple Biological Activities of Rhododendron przewalskii Maxim. Extracts and UPLC-ESI-Q-TOF/MS Characterization of Their Phytochemical Composition

“…The fungi Aspergillus niger (ATCC 9642), Candida albicans (ATCC 10231) and Saccharomyces cerevisiae (ATCC 7753) were obtained from the American Type Culture Collection (ATCC). According to described methods ( Obistioiu et al, 2014 ; Liu et al, 2018a ; Alonso-Esteban et al, 2019 ), the antifungal activities of the AERP and EERP at 5 mg/ml and 2 mg/ml were tested by measuring the diameter of clear inhibition zone. Briefly, a volume of 100 μL of fungi suspensions (1 × 10 6 CFU/ml) were streaked on the surface of Sabouraud Dextrose Agar (SDA, Solarbio, China) for fungal cultures.…”

In Vitro Interactions of Moroccan Propolis Phytochemical’s on Human Tumor Cell Lines and Anti-Inflammatory Properties

“…All the cells were routinely maintained as adherent cell cultures in RPMI-1640 medium, containing 10% FBS, 2 mM glutamine, 100 U/mL penicillin, and 100 µg/mL streptomycin, and kept at 37 °C in a humidified air incubator containing 5% CO 2 . The cytotoxic potential of the propolis samples was evaluated by the sulforhodamine B (SRB) assay, according to the procedure described previously [18]. For hepatotoxicity evaluation, a cell culture was prepared from a freshly harvested porcine liver obtained from a local slaughterhouse, according to an established procedure, and designated as PLP2 (porcine liver primary culture).…”

The Promising Ability of Humulus lupulus L. Iso-α-acids vs. Diabetes, Inflammation, and Metabolic Syndrome: A Systematic Review

“…Hop’s female inflorescences, also called hop cones, contain resin glands capable of secreting a yellow resinous powder known as lupulin. It is rich in different active compounds that contribute to beer aroma and stability, and that can be classified as volatile oils, bitter acids, and polyphenols [ 10 ]. Several of these molecules have been demonstrated to exert different biological activities.…”