Safety Assessment of Citrus-Derived Peel Oils as Used in Cosmetics

Essential oils for clinical aromatherapy: A comprehensive review

ETHNOPHARMACOLOGICAL RELEVANCE

Aromatherapy, a holistic healing practice utilizing the aromatic essences of plant-derived essential oils, has gained significant attention for its therapeutic potential in promoting overall well-being. Use of phytoconstituent based essential oil has played a significant role in the evolving therapeutic avenue of aromatherapy as a complementary system of medicine.

AIM OF THE STUDY

This comprehensive review article aims to explore the usage of essential oils for aromatherapy, shedding light on their diverse applications, scientific evidence, and safety considerations. Furthermore, the growing interest in using essential oils as complementary therapies in conjunction with conventional medicine is explored, underscoring the significance of collaborative healthcare approaches.

MATERIALS AND METHODS

Literature search was performed from databases like PubMed, ScienceDirect, Scopus, and Bentham using keywords like Aromatherapy, Aromatic Plants, Essential oils, Phytotherapy, and complementary medicine. The keywords were used to identify literature with therapeutic and mechanistic details of herbal agents with desired action.

RESULTS

The integration of traditional knowledge with modern scientific research has led to a renewed interest in essential oils as valuable tools in contemporary healthcare. Various extraction methods used to obtain essential oils are presented, emphasizing their impact on the oil's chemical composition and therapeutic properties. Additionally, the article scrutinizes the factors influencing the quality and purity of essential oils, elucidating the significance of standardization and certification for safe usage. A comprehensive assessment of the therapeutic effects of essential oils is provided, encompassing their potential as antimicrobial, analgesic, anxiolytic, and anti-inflammatory agents, among others. Clinical trials and preclinical studies are discussed to consolidate the existing evidence on their efficacy in treating diverse health conditions, both physical and psychological. Safety considerations are of paramount importance when employing essential oils, and this review addresses potential adverse effects, contraindications, and best practices to ensure responsible usage.

CONCLUSIONS

This comprehensive review provides valuable insights into the exploration of essential oils for aromatherapy, emphasizing their potential as natural and potent remedies for a wide range of ailments. By amalgamating traditional wisdom and modern research, this article aims to encourage further investigation into the therapeutic benefits of essential oils while advocating for their responsible and evidence-based incorporation into healthcare practices.

Allergens grouping names on packaging: Are the substances similar enough to ensure safety? The worst case scenarios question this

OBJECTIVE

European Commission Regulation (EU) n°2023/1545 introduced the concept of grouping names in the cosmetics sector in July 2023. These groups bring together allergenic substances with the same level of skin sensitization. Their purpose is to lighten the list of ingredients on cosmetic packaging, by grouping together substances deemed to be similar under the same name. As this classification is based on a single toxic effect - skin sensitization - the present study aims to analyse the relevance of these groupings with regard to other toxic effects of substances in the same group.

METHODS

This study was carried out by consulting an available database, various reports from 5 committees, 2 books and 5 articles in order to complete the toxicological profile of each substance. Then, in order to highlight any discrepancies within the classification, the worst cases were identified. For this purpose, the data for each substance in a group were compared, and in the event of greater criticality for a toxic effect, this was qualified as a worst case. In addition, similar toxic effects between several substances within the same group were also recorded. The aim of this additional research was to validate the definition of the grouping name and the similarities between substances in the same group.

RESULTS

From the 17 grouping names, 5 presented worst cases. Two groups had 2 worst cases and the others only one. In total, from the 7 worst cases detected, 3 were due to the toxic effect "skin irritation". In most cases, the substances in the groupings shared the presence or absence of risk. Only the degree of risk criticality varied.

CONCLUSION

Classification by grouping names appears justified regarding the similarities between substances, particularly in terms of skin sensitization. However, the presence of worst cases qualifies it and highlights the importance of being vigilant when assessing the risk of cosmetic products including these grouping names in their list of ingredients.

Elaboration and characterization of nanoemulsion with orange essential oil and pectin

BACKGROUND

Nanoemulsions formulated with citric essential oils are currently of interest because of their physical and chemical properties and multiple applications in areas such as the food industry or agrochemicals. These are thermodynamically unstable and have almost Newtonian flow behaviour, but a suitable formulation allows systems to be obtained with good physical stability and rheological properties. The addition of pectin makes this possible. In this work, food nanoemulsions formulated with pectin, orange essential oil (5 wt%), and Tween 80 were obtained by microfluidization. First, the effect of Tween 80 concentration from 1 to 5 wt% on emulsions without pectin was evaluated. Then, pectin was added to the most stable nanoemulsion obtained and two variables were studied: the pectin solution concentration (from 2 to 6 wt%) and the pectin/emulsion ratio (1:1 or 2:1) at a fixed pectin concentration.

RESULTS

Rheological, laser diffraction, and multiple light scattering techniques were employed to determine the content of Tween 80 that results in the most stable nanoemulsion without pectin, which was 3 wt%. In addition, these techniques were used to determine the structure and physical stability of the nanoemulsions containing orange essential oil and pectin. The results obtained showed that the emulsions containing 2 wt% pectin were destabilized before 24 h. Furthermore, the emulsion with 6 wt% pectin and a 2:1 pectin/emulsion ratio showed the highest viscosity and the lowest mean diameters, and therefore the greatest stability.

CONCLUSION

This work extends the knowledge of formulation of nanoemulsions and using essential oils. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

In Vitro Assessment of the Cytotoxic and Antiproliferative Profile of Natural Preparations Containing Bergamot, Orange and Clove Essential Oils

Medicinal plants and essential oils (EOs), in particular, were intensively studied in recent years as viable alternatives for antiproliferative chemical synthetic agents. In the same lines, the present study focuses on investigating the effects of natural preparations (emulsions) based on EOs obtained from Citrus bergamia Risso (bergamot-BEO), Citrus sinensis Osbeck (orange-OEO), and Syzygium aromaticum Merill et L. M. Perry (clove-CEO) on different healthy (human immortalized keratinocytes—HaCaT and primary human gingival fibroblasts—HGF) and human tumor cell lines (human melanoma—A375 and oral squamous carcinoma—SCC-4) in terms of the cells’ viability and cellular morphology. The obtained results indicate that the CEO emulsion (ECEO) induced a dose-dependent cytotoxic in both healthy (HaCaT and HGF) and tumor (A375 and SCC-4) cells. OEO emulsion (EOEO) increased cell viability percentage both for HaCaT and A375 cells and had an antiproliferative effect at the highest concentration in HGF and SCC-4 cells. BEO emulsion (EBEO) decreased the viability percentage of SCC-4 tumor cells. By associating OEO with CEO as a binary mixture in an emulsified formulation, the inhibition of tumor cell viability increases. The E(BEO/OEO) binary emulsion induced an antiproliferative effect on oral health and tumor cells, with a minimal effect on skin cells. The non-invasive tests performed to verify the safety of the test compound’s emulsions at skin level indicated that these compounds do not significantly modify the physiological skin parameters and can be considered safe for human skin.

Essential Oils and Their Individual Components in Cosmetic Products

The current consumer demands together with the international regulations have pushed the cosmetic industry to seek new active ingredients from natural renewable sources for manufacturing more eco-sustainability and safe products, with botanical extract being an almost unlimited source of these new actives. Essential oils (EOs) emerge as very common natural ingredients in cosmetics and toiletries as a result of both their odorous character for the design and manufacturing of fragrances and perfumes, and the many beneficial properties of their individual components (EOCs), e.g., anti-inflammatory, antimicrobial and antioxidant properties, and, nowadays, the cosmetic industry includes EOs or different mixtures of their individual components (EOCs), either as active ingredients or as preservatives, in various product ranges (e.g., moisturizers, lotions and cleanser in skin care cosmetics; conditioners, masks or antidandruff products in hair care products; lipsticks, or fragrances in perfumery). However, the unique chemical profile of each individual essential oil is associated with different benefits, and hence it is difficult to generalize their potential applications in cosmetics and toiletries, which often require the effort of formulators in seeking suitable mixtures of EOs or EOCs for obtaining specific benefits in the final products. This work presents an updated review of the available literature related to the most recent advances in the application of EOs and EOCs in the manufacturing of cosmetic products. Furthermore, some specific aspects related to the safety of EOs and EOCs in cosmetics will be discussed. It is expected that the information contained in this comprehensive review can be exploited by formulators in the design and optimization of cosmetic formulations containing botanical extracts.

Citrus aurantium L. Active Constituents, Biological Effects and Extraction Methods. An Updated Review

Citrus genus is a prominent staple crop globally. Long-term breeding and much hybridization engendered a myriad of species, each characterized by a specific metabolism generating different secondary metabolites. Citrus aurantium L., commonly recognized as sour or bitter orange, can exceptionally be distinguished from other Citrus species by unique characteristics. It is a fruit with distinctive flavor, rich in nutrients and phytochemicals which possess different health benefits. This paper presents an overview of the most recent studies done on the matter. It intends to provide an in-depth understanding of the biological activities and medicinal uses of active constituents existing in C. aurantium. Every plant part is first discussed separately with regards to its content in active constituents. All extraction methods, their concepts and yields, used to recover these valuable molecules from their original plant matrix are thoroughly reported.

Advantages of Hyaluronic Acid and Its Combination with Other Bioactive Ingredients in Cosmeceuticals

This study proposes a review on hyaluronic acid (HA) known as hyaluronan or hyaluronate and its derivates and their application in cosmetic formulations. HA is a glycosaminoglycan constituted from two disaccharides (N-acetylglucosamine and D-glucuronic acid), isolated initially from the vitreous humour of the eye, and subsequently discovered in different tissues or fluids (especially in the articular cartilage and the synovial fluid). It is ubiquitous in vertebrates, including humans, and it is involved in diverse biological processes, such as cell differentiation, embryological development, inflammation, wound healing, etc. HA has many qualities that recommend it over other substances used in skin regeneration, with moisturizing and anti-ageing effects. HA molecular weight influences its penetration into the skin and its biological activity. Considering that, nowadays, hyaluronic acid has a wide use and a multitude of applications (in ophthalmology, arthrology, pneumology, rhinology, aesthetic medicine, oncology, nutrition, and cosmetics), the present study describes the main aspects related to its use in cosmetology. The biological effect of HA on the skin level and its potential adverse effects are discussed. Some available cosmetic products containing HA have been identified from the brand portfolio of most known manufacturers and their composition was evaluated. Further, additional biological effects due to the other active ingredients (plant extracts, vitamins, amino acids, peptides, proteins, saccharides, probiotics, etc.) are presented, as well as a description of their possible toxic effects.

Essential Oils as Natural Sources of Fragrance Compounds for Cosmetics and Cosmeceuticals

Fragrance is an integral part of cosmetic products and is often regarded as an overriding factor in the selection of cosmetics among consumers. Fragrances also play a considerable role in masking undesirable smells arising from fatty acids, oils and surfactants that are commonly used in cosmetic formulations. Essential oils are vital assets in the cosmetic industry, as along with imparting pleasant aromas in different products, they are able to act as preservatives and active agents and, simultaneously, offer various benefits to the skin. Moreover, the stimulating demand for natural ingredients has contributed massively to a renewed interest in cosmetic and wellness industries in plant derivatives, especially essential oils. This has led popular cosmetic companies to endorse natural fragrances and opt for minimally processed natural ingredients, given the potentially adverse health risks associated with artificial fragrance chemicals, which are major elements of cosmetics. Among the high-valued essential oils used as fragrances are citrus, lavender, eucalyptus, tea tree and other floral oils, among others, while linalool, geraniol, limonene, citronellol, and citral are much-appreciated fragrance components used in different cosmetics. Thus, this review aimed to highlight the enormous versatility of essential oils as significant sources of natural fragrances in cosmetics and cosmeceuticals. Moreover, a special focus will be laid on the different aspects related to essential oils such as their sources, market demand, chemistry, fragrance classification, aroma profile, authenticity and safety.