Abstract
Rosemary (Rosmarinus officinalis L.) is known to be an effective potential source of natural antioxidants which confer benefits to human health. Their bioactive properties are mainly due to phenolic compounds but these molecules are highly vulnerable to oxidants, light, heat, pH, water and enzymatic activities. Therefore, the stability and shelf life of phenolic compounds should be increased by being protected from chemical and physical damage by means of encapsulation prior to application. Encapsulation is becoming increasingly important in the pharmaceutical, food, cosmetics, textile, personal care, chemical, biotechnology, and medicinal industries due to its potential for stabilization and delivery of delicate and precious bioactive compounds. The aim of the present work was to describe the polyphenolic profile of Tunisian Rosemary, collected from two different bioclimatic areas, and further loading in silk fibroin nanoparticles. The loaded nanoparticles were characterized in terms of morphology, size, polydispersity, Z-potential, secondary structure of the protein, encapsulation efficiency, loading content, and antioxidant activity. On one hand, HPLC analysis revealed the presence of 18 polyphenolic compounds of whichcarnosic acid and carnosol were found to be the most abundant compounds (46.3 to 76.4 and 22.4 to 43.5 mg of compound per gram of dry plant weight (mg/g DPW) respectively), Total phenolic content (TPC) ranged from 85.8 to 137.3 mg of gallic acid equivalent (GAE)/g DPW in post-distilled rosemary extracts andantioxidant activity reached the values of 5.9 to 8.3 µmol of ascorbic acid equivalent (AAE)/g DPW). On the other hand loaded nanoparticles were almost spherical and presented nanometric size and negative Z-potential. Although the encapsulation efficiency in silk fibroin nanoparticles and the drug loading content were low in the conditions of the assay, the encapsulated polyphenols retained near 85% of the radical scavenging activity against DPPH· after 24 h. of incubation at 37 °C. The results showed that post-distilled rosemary residues had an effective potential as natural antioxidants due to their significant antioxidant activity and seemed to be useful in both pharmaceutical and food industries with beneficial properties that might confer benefits to human health and these silk fibroin nanoparticles loaded with rosemary extracts are thus a promising combination for several applications in food technology or nanomedicine.
Highlights
Rosemary (Rosmarinus officinalis L.) is a perennial herb that belongs to the Lamiaceae family, which is cultivated as medicinal plant in different areas of the world, such as the Mediterranean, Asia, and Latin America [1]
Eighteen phenolics compounds were identified in the methanolic extracts of rosemary, including four phenolic acids, five phenolic diterpenes, and nine flavonoids
When the diterpenic fraction is analysed this pattern changes, carnosic acid, major diterpene identified and precursor of the rest of diterpenes quantified in these extracts, was detected at the highest concentration in plants harvested at the Gafsa–Orbata (GO) population (p < 0.05), located in an arid low bioclimatic area, where the climatic conditions are the most extreme among the areas under study
Summary
Rosemary (Rosmarinus officinalis L.) is a perennial herb that belongs to the Lamiaceae family, which is cultivated as medicinal plant in different areas of the world, such as the Mediterranean, Asia, and Latin America [1]. Leaves of rosemary have been used for a long time in Mediterranean cuisine, to improve or modify the flavour of foods, and to inhibit its deterioration. Dried leaves, or their extracts, are characterized by their richness in phenolic compounds with known anti-inflammatory, antioxidant, antiaging, antibacterial, and anticancer properties [3,4]. Several flavonoids and phenolic compounds, such as hispidulin, cirsimaritin, apigenin, genkwanin, naringin, rutin, caffeic acid, and rosmarinic acid have been described as components of these rosemary extracts [7,8,9]. The importance of describing and quantifying these components relies on the potential biological activities that most of them exhibit
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
