Linoleic acid and squalene are oxidized by discrete oxidation mechanisms in human sebum

Induction of ferroptosis in human keratinocyte HaCaT cells by squalene hydroperoxide: Possible prevention of skin ferroptosis by botanical extracts

Ever since the proposal of ferroptosis, it has been studied as a nonapoptotic cell death caused by iron ion-dependent phospholipid (PL) peroxidation. We previously showed that treatment of human hepatoma cell line HepG2 with prepared PL hydroperoxide (PLOOH) resulted in ferroptosis. However, in human sebum, the major hydroperoxide is not PLOOH but squalene hydroperoxide (SQOOH), and to our knowledge, it is not established yet whether SQOOH induces ferroptosis in the skin. In this study, we synthesized SQOOH and treated human keratinocyte HaCaT cells with SQOOH. The results showed that SQOOH induces ferroptosis in HaCaT cells in the same way that PLOOH causes ferroptosis in HepG2 cells. Some natural antioxidants (botanical extracts) could inhibit the ferroptosis in both the cell types. Consequently, future research focus would revolve around the involvement of SQOOH-induced ferroptosis in skin pathologies as well as the prevention and treatment of skin diseases through inhibition of ferroptosis by botanical extracts.

Squalene Peroxidation and Biophysical Parameters in Acne-Prone Skin: A Pilot "In Vivo" Study

Nowadays, acne vulgaris therapies are often unsuccessful. One of the responsible factors for the formation of comedones and inflammatory lesions could be the peroxidation of squalene, a hydrocarbon representing one of the major components of human sebum. This peroxidation is increased by solar irradiation. The purpose of this work was to set up an in vivo method for the extraction and quantification of squalene from acne skin and to correlate the results with biophysical skin parameters such as sebum amount, protein content and TEWL. Healthy volunteers were used as control. The results obtained demonstrated that acne-prone skin had a major quantity of squalene, and, in the stratum corneum area, its peroxide form is present. Moreover, Spearman's rank correlation showed a positive correlation between sebum content and peroxide squalene and between porphyrin intensity and peroxide squalene.

Antioxidants for improved skin appearance: Intracellular mechanism, challenges and future strategies

Recent advances in molecular and biochemical processes relevant to the skincare field have led to the development of novel ingredients based on antioxidants that can improve skin health and youthfulness. Considering the plethora of such antioxidants and the many implications for the skin's appearance, this review focuses on describing the critical aspects of antioxidants, including cosmetic functions, intracellular mechanisms and challenges. In particular, specialized substances are suggested for the treatment of each skin condition, such as skin ageing, skin dehydration and skin hyperpigmentation, which treatments can maximize effectiveness and avoid side effects during skin care processes. In addition, this review proposes advanced strategies that either already exists in the cosmetic market or should be developed to improve and optimize cosmetic' beneficial effects.

Significance of Singlet Oxygen Molecule in Pathologies

Reactive oxygen species, including singlet oxygen, play an important role in the onset and progression of disease, as well as in aging. Singlet oxygen can be formed non-enzymatically by chemical, photochemical, and electron transfer reactions, or as a byproduct of endogenous enzymatic reactions in phagocytosis during inflammation. The imbalance of antioxidant enzymes and antioxidant networks with the generation of singlet oxygen increases oxidative stress, resulting in the undesirable oxidation and modification of biomolecules, such as proteins, DNA, and lipids. This review describes the molecular mechanisms of singlet oxygen production in vivo and methods for the evaluation of damage induced by singlet oxygen. The involvement of singlet oxygen in the pathogenesis of skin and eye diseases is also discussed from the biomolecular perspective. We also present our findings on lipid oxidation products derived from singlet oxygen-mediated oxidation in glaucoma, early diabetes patients, and a mouse model of bronchial asthma. Even in these diseases, oxidation products due to singlet oxygen have not been measured clinically. This review discusses their potential as biomarkers for diagnosis. Recent developments in singlet oxygen scavengers such as carotenoids, which can be utilized to prevent the onset and progression of disease, are also described.

Microencapsulation protects the biological activity of sea buckthorn seed oil

Introduction

Sea buckthorn (Hippophae rhamnoides) seed oil is rich in unsaturated fatty acids, and is thus susceptible to oxidation and rancidity. Microencapsulation technology allows the effective protection of active substances, thereby prolonging the deterioration time and shelf life.

Methods

In this study, H. rhamnoides microcapsules were prepared using a spray-drying method, and the microencapsulation parameters were optimized. The morphological characteristics, structural parameters, and stability of the microcapsules were determined using scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and oil oxidation stability testing.

Results

Based on encapsulation efficiency (EE, %) and the particle size (D50) of the microcapsules, the optimal preparation conditions were characterized as a wall material consisting of soy protein isolate and soybean polysaccharide (2:3), a wall concentration of 15%, a core-to-wall ratio of 1:3, and an inlet temperature of 160°C. Under these optimal conditions, the encapsulation efficiency was 95.30 ± 2.67%, with a yield of 57.03 ± 3.71% and a particle size of 7.96 ± 1.04 μm.

Discussion

Furthermore, the effectiveness of microencapsulation in protecting the biological activity of H. rhamnoides seed oil was confirmed by an antioxidation test. Thus, the results of this study showcase the successful microencapsulation of H. rhamnoides seed oil, thereby significantly improving its stability.