The dermatocosmetics industry is experiencing a surge in demand for natural and sustainable skincare products, driven by consumer concerns regarding synthetic chemicals. Plant-based ingredients, like rosemary (Rosmarinus officinalis L.), are gaining traction due to their bioactive properties that offer multiple benefits for skin health. Rosemary is rich in polyphenols and essential oils, contributing to its antioxidant, antimicrobial, and anti-inflammatory activities. This has led to increased scientific interest in rosemary-based applications, particularly in dermatocosmetic formulations. However, comparative studies on the influence of regional factors and extraction methods on rosemary’s bioactive composition remain limited. This study addresses these gaps by comparing rosemary extracts from Dobrogea (Romania) and the Bulgarian coastal area, examining the effects of different ethanol concentrations on bioactive compound extraction, and evaluating the antimicrobial activity of the extracts.
Methods
Fresh rosemary leaves were collected from Dobrogea, Romania, and the Bulgarian coastal area. Rosemary hydroalcoholic macerates were prepared using ethanol at 96%, 70%, and 40%. The total polyphenol content (TPC) was determined using the Folin–Ciocâlteu method, while antioxidant activity was evaluated using the DPPH radical scavenging assay. Metal concentrations were analyzed through atomic absorption spectrometry (AAS)6. The antimicrobial activity of the rosemary macerates was tested against Escherichia coli, Staphylococcus aureus, and Candida albicans.
Results
•Total Phenolic Content (TPC) and Antioxidant Activity:
◦The highest TPC was found in Dobrogean rosemary macerated with 70% ethanol (RDS2), reaching 2155 ± 2.45 mg GAE/100 g f.w..
◦Dobrogean rosemary samples consistently demonstrated higher TPCs than their Bulgarian counterparts.
◦The Dobrogean rosemary macerate (RDS2) exhibited the highest radical scavenging activity (745.0 ± 2.33 mg GAE/100 g f.w.).
◦Solvent polarity plays a critical role, with 70% ethanol providing higher extraction yields.
•Total Flavonoid Content (TFC):
◦The highest TFC value was observed in the Dobrogean sample macerated with 70% ethanol (RDS2), with a value of 283.6 ± 1.52 mg QE/100 g fresh weight.
◦Samples with higher TFCs, such as RDS2 and RBS2, showed stronger radical scavenging activity, confirming the role of flavonoids in increasing the biological efficacy of rosemary.
•Mineral Content:
◦Dobrogean rosemary samples (RD) showed higher concentrations of essential minerals compared to Bulgarian samples (RB).
◦The highest concentration was observed for calcium (Ca), with RD samples containing 119.5 mg/kg.
◦Trace elements, including zinc (Zn) and iron (Fe), were present in higher concentrations in the RD samples.
•Antimicrobial Activity:
◦RDS2 macerate exhibited superior antimicrobial activity compared to RBS2, particularly against Gram-positive bacteria and yeast.
◦Staphylococcus aureus demonstrated greater sensitivity to both extracts compared to Escherichia coli.
•Dermatocosmetic Preparations:
◦All dermatocosmetic preparations analyzed exhibited homogeneity and stability.
◦The pH values of the preparations are compatible with the physiological pH of the skin.
◦The spreadability parameters remained stable over time, indicating the formulations’ consistency and suitability for prolonged use.
•Antioxidant Capacity of Preparations:
◦The highest antioxidant activities were shown by Formula C (cream formulation containing RDS2), followed by Formula A (hydrogel containing RDS2).
•Anti-Inflammatory Activity:
◦Dermatocosmetic creams showed a greater anti-inflammatory effect compared to hydrogels.
◦Formula C exhibited the most pronounced anti-inflammatory activity.
This study demonstrates the superior bioactive properties of Dobrogean rosemary compared to its Bulgarian counterpart, particularly when extracted using 70% ethanol. The resulting extracts exhibit significant antioxidant, antimicrobial, and anti-inflammatory properties, making them promising ingredients for dermatocosmetic applications. The development of stable hydrogels and creams incorporating these extracts further highlights their potential for soothing and therapeutic dermatological products. The novelty of this research lies in its comparative evaluation of rosemary from different geographical regions and its comprehensive analysis of the dermatocosmetic potential of hydroalcoholic macerates. Future studies should focus on optimizing extraction methods, improving antimicrobial activity against Gram-negative bacteria, and expanding the range of skincare applications.
Link to the study: https://www.mdpi.com/2310-2861/11/3/149
