Oxidative stress plays a major role in the skin aging process through the reactive oxygen species production and advanced glycation end products (AGEs) formation. Antioxidant ingredients are therefore needed in the skin care market and the use of molecules coming from plant cell cultures provide a unique opportunity. In this paper, the features of an hydroethanolic extract obtained by Jasminum sambac cells (JasHEx) were explored. The antioxidant and anti-AGE properties were investigated by a multidisciplinary approach combining mass spectrometric and bio-informatic in vitro and ex vivo experiments. JasHEx contains phenolic acid derivatives, lignans and triterpenes and it was found to reduce cytosolic reactive oxygen species production in keratinocytes exposed to exogenous stress. It also showed the ability to reduce AGE formation and to increase the collagen type I production in extracellular matrix. Data demonstrated that JasHEx antioxidant properties were related to its free radical scavenging and metal chelating activities and to the activation of the Nrf2/ARE pathway. This can well explain JasHEx anti-inflammatory activity related to the decrease in NO levels in LPS-stimulated macrophages. Thus, JasHEx can be considered a powerful antioxidant booster against oxidative stress-induced skin aging.

Skin aging is a very well-known process setting a gradual worsening of skin mechanical features due to a decline in the production of the extra-cellular matrix machinery and to a concurrent change in the contraction process. To slow this progression, it is crucial to induce the expression of several proteins able to promote elastic fibers formation and tissue repair. Here, the Oenothera biennis cell culture aqueous extract has been investigated from a chemical point of view and then it was tested in vitro, in cell, and in ex vivo experiments as adjuvant in counteracting skin aging. Accordingly, it has been shown that the Oenothera biennis extract was able, by increasing MYLK gene expression, to promote matrix collagen contraction, actin polymerization, and the production of essential ECM proteins.

Accumulation of senescent dermal fibroblasts drives skin aging. The reactivation of proliferation is one strategy to modulate cell senescence. Recently, we reported the exact chemical composition of the hydrophilic extract of Oenothera biennis cell cultures (ObHEx) and we showed its skin anti-aging properties. The aim of this work is to assess its biological effect specifically on cell senescence. ObHEx action has been evaluated on normal human dermal fibroblasts subjected to stress-induced premature senescence (SIPS) through an ultra-deep proteomic analysis, leading to the most global senescence-associated proteome so far. Mass spectrometry data show that the treatment with ObHEx re-establishes levels of crucial mitotic proteins, strongly downregulated in senescent cells. To validate our proteomics findings, we proved that ObHEx can, in part, restore the activity of ‘senescence-associated-ß-galactosidase’, the most common hallmark of senescent cells. Furthermore, to assess if the upregulation of mitotic protein levels translates into a cell cycle re-entry, FACS experiments have been carried out, demonstrating a small but significative reactivation of senescent cell proliferation by ObHEx. In conclusion, the deep senescence-associated global proteome profiling published here provides a panel of hundreds of proteins deregulated by SIPS that can be used by the community to further understand senescence and the effect of new potential modulators. Moreover, proteomics analysis pointed to a specific promitotic effect of ObHEx on senescent cells. Thus, we suggest ObHEx as a powerful adjuvant against senescence associated with skin aging.

The skin barrier is essential for maintaining epidermal homeostasis and preventing transepidermal water loss (TEWL). This study investigated the ability of a Hyssopus officinalis cell culture hydroethanolic extract to support epidermal barrier function by modulating ceramide-related enzymes and structural proteins. Hydroethanolic extracts from cell cultures grown under light and dark conditions were characterized by high-resolution mass spectrometry. Dark-grown cultures accumulated higher levels of rosmarinic acid, hydroxytyrosol glycosides, and polymethoxyflavones than light-grown cultures and intact plants. In keratinocytes, the extract from dark-grown cells (HoEx) at 0.002% w/v exhibited significant antioxidant activity (20% ROS reduction) and increased β-glucocerebrosidase (GBA) activity (25%) as well as the expression of β-glucocerebrosidase (44%), serine palmitoyltransferase (34%), involucrin (17%), and filaggrin (44%) compared with control. In human skin explants, 0.5% w/w HoEx increased ceramide content (36%) and total epidermal lipid levels (99%) relative to control. In a clinical study involving 10 volunteers with mechanically stressed skin, 0.5% w/w HoEx increased GBA activity by 30% and reduced TEWL by 15%, whereas placebo treatment led to a 55% decrease in GBA activity and a 25% increase in TEWL. Collectively, these findings indicate that HoEx modulates multiple epidermal pathways involved in lipid processing and differentiation under in vitro, ex vivo, and stressed in vivo conditions. While the study was not designed to establish mechanistic causality, the coordinated modulation of ceramide-related enzymes, structural proteins, and TEWL suggests that HoEx may support epidermal barrier function within the limits of the tested models. HoEx therefore represents a standardized source of bioactive compounds with potential relevance for dermocosmetic applications.