Polyphenolic Extract from Sambucus ebulus L. Leaves Free and Loaded into Lipid Vesicles.

Ramona-Daniela Păvăloiu,Mona Mihailescu,Georgeta Neagu,Fawzia Sha’At,Cristian Matei,Mihai Anastasescu,Daniela Berger,Corina Bubueanu,Mihaela Deaconu,Mousa Sha’At,Gheorghe Nechifor

doi:10.3390/nano10010056

Abstract

The paper deals with the preparation and characterisation of hydroalcoholic polyphenolic extract from Sambucus ebulus (SE) leaves that was further loaded into three-types of lipid vesicles: liposomes, transfersomes, and ethosomes, to improve its bioavailability and achieve an optimum pharmacological effect. For Sambucus ebulus L.-loaded lipid vesicles, the entrapment efficiency, particle size, polydispersity index and stability were determined. All prepared lipid vesicles showed a good entrapment efficiency, in the range of 75–85%, nanometric size, low polydispersity indexes, and good stability over three months at 4 °C. The in vitro polyphenols released from lipid vehicles demonstrated slower kinetics when compared to the free extract dissolution in phosphate buffer solution at pH 7.4. Either free SE extract or SE extract loaded into lipid vesicles demonstrated a cytoprotective effect, even at low concentration, 5 ug/mL, against hydrogen peroxide-induced toxicity on L-929 mouse fibroblasts’ cell lines. However, the cytoprotective effect depended on the time of the cells pre-treatment with SE extract before exposure to a hydrogen peroxide solution of 50 mM concentration, requiring at least 12 h of pre-treatment with polyphenols with radical scavenging capacity.

Highlights

The Sambucus ebulus (SE) leaves extract was characterized for total polyphenols content, chemical profiling, radical scavenging capacity, and cytoprotective effect on hydrogen peroxide-induced toxicity on the L-929 fibroblast cell line
A hydroalcoholic polyphenols extract from Sambucus ebulus leaves was prepared and characterized using total polyphenols content (25.50 ± 0.010 mg GAE/g dry material), and radical scavenging activity using DPPH assay (IC50 = 10.33 ± 0.056 μg/mL) and reverse phase high-performance liquid chromatography (HPLC)-PDA analysis, which showed the presence of chlorogenic acid, caffeic acid, rutin, and quercetin
SE leaves extract was further loaded into three types of lipid vesicles: liposomes, transfersomes and ethosomes, which were characterized through their entrapment efficiency, Atomic force microscopy (AFM), enhanced dark-field microscopy, scanning electron microscopy (SEM) and dynamic light scattering (DLS) measurements

Summary

Introduction

SE leaves are widely used in herbal medicine for the treatment of kidney and lung diseases, inflammation-related gastrointestinal disorders, rheumatoid arthritis, fever, infections, sore throat, and bites [1,2,3,4]. Several studies revealed that SE leaves comprise various compounds such as flavonoids, polyphenols, triterpenes, tannins, iridoids, phytosterols, lectins, sugars, fibers, vitamins, and minerals [5,6,7,8]. The main therapeutic benefits of SE extracts are related to their antioxidant and anti-inflammatory properties, making them valuable sources for food, cosmetic and pharmaceutical industries, as well as medicine. The compounds from SE extract exhibit poor water solubility, which limits their bioavailability and therapeutic applications. Because of domestic processes (thermal and mechanical) and storage conditions, most of the bioactive substances of SE extract are susceptible to degradation, and a significant portion of phytochemicals is not absorbed [9,10]

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Results

Conclusion