Impact of Organic Fertilization on Polyphenolic Content in Milk Thistle (Silybum marianum L. Gaertn.) Genotypes from Romania

Silybum marianum (L.) Gaertn. is a major source of active principles, but also a plant that perfectly meets the needs of sustainable agriculture. The present research analyses the efficiency of organic fertilization for the increase of active principles in the fruits of milk thistle cultivated in the area of Măciuca, southern Vâlcea County, Romania. The aim of this work was the spectrophotometric determination of the total polyphenols content (TPC) of five different genotypes of milk thistle (Prahova, a1; Secuieni, a2; Iași, a3; Dacia Plant, a4; Brașov, a5) both unfertilized, and treated with organic fertilizers. Significant quantitative differences were identified between the five populations of Silybum marianum, the genotypes "Dacia Plant" fertilized and "Prahova" unfertilized presenting the highest TPC (18.87 mg GAE/g, 18.15 mg GAE/g, respectively). Fertilization did not necessarily have an impact on the accumulation of polyphenols in the fruits, but the climatic and soil conditions, as well as the genetic background being able to influence the quality of the milk thistle fruits

Origanum vulgare mediated green synthesis of biocompatible gold nanoparticles simultaneously possessing plasmonic, antioxidant and antimicrobial properties

Daniela Benedec,1,* Ilioara Oniga,1,* Flavia Cuibus,1 Bogdan Sevastre,2 Gabriela Stiufiuc,3 Mihaela Duma,4 Daniela Hanganu,1 Cristian Iacovita,1 Rares Stiufiuc,1,5 Constantin Mihai Lucaciu1 1Faculty of Pharmacy, “Iuliu Haţieganu” University of Medicine and Pharmacy, 2Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine, 3Faculty of Physics, “Babeş Bolyai” University, 4State Veterinary Laboratory for Animal Health and Safety, 5Department of Bionanoscopy, MedFuture Research Center for Advance Medicine, “Iuliu Haţieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania *These authors contributed equally to this work Purpose: The leaves and flowering stem of Origanum vulgare contain essential oils, flavonoids, phenolic acids and anthocyanins. We propose a new, simple, one-pot, O. vulgare extract (OVE) mediated green synthesis method of biocompatible gold nanoparticles (AuNPs) possessing improved antioxidant, antimicrobial and plasmonic properties.Materials and methods: Different concentrations of OVEs were used to reduce gold ions and to synthetize biocompatible spherical AuNPs. Their morphology and physical properties have been investigated by means of transmission electron microscopy, ultraviolet–visible absorption spectroscopy, photon correlation spectroscopy and Fourier transform infrared spectroscopy, whereas their plasmonic properties have been tested using surface-enhanced Raman spectroscopy (SERS). The antioxidant properties of nanoparticles (NPs) have been evaluated by 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay, and the antimicrobial tests were performed using the disk diffusion assay. Their cytotoxicity has been assessed by means of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Results: The experimental results confirmed the successful synthesis of biocompatible, spherical, plasmonic NPs having a mean diameter of ~40 nm and an outstanding aqueous stability. This new class of NPs exhibits a very good antioxidant activity and presents interesting inhibitory effects against Staphylococcus aureus and Candida albicans. Due to their plasmonic properties, AuNPs are used as SERS substrates for the detection of a test molecule (methylene blue) up to a concentration of 10-7 M and a pharmaceutical compound (propranolol) in solution. Cytotoxicity assays revealed that AuNPs are better tolerated by normal human dermal fibroblast cells, while the melanoma cancer cells are more sensitive.Conclusion: The biocompatible AuNPs synthetized using OVEs showed significant bactericidal and antimycotic activities, the most sensitive microorganisms being S. aureus and C. albicans, both commonly involved in various dermatological infections. Moreover, the significant antioxidant effect might recommend their use for protective and/or preventive effect in various skin inflammatory conditions, including the reduction in side effects in dermatological infections. Meanwhile, the as-synthesized biocompatible AuNPs can be successfully used as SERS substrates for the detection of pharmaceutical compounds in aqueous solutions. Keywords: green nanoparticles’ synthesis, toxicity, antioxidant activity, Staphylococcus aureus, Candida albicans, SER