Buddleja davidii stem cells limit photodamage

. Indeed, once endogenous antioxidative defences have been exhausted, these free radicals are free to damage the molecular structures of the cell (proteins, lipids and DNA). Moreover, as a consequence of UV exposure, inflammatory phenomena not only lead to the generation of further free radicals, but also trigger the release of chemical mediators. These, in turn, provoke the activation of matrix metalloproteinase (MMP), enzymes responsible for the degradation of the main components of the extracellular matrix, thereby inducing a loss of cutaneous elasticity and tone and other classic signs of photo-ageing. Scientific literature reports that metalloproteinase activation is induced by extended stimulation of keratinocyte and fibroblast membrane receptors, able to regulate the expression of genes for these enzymes, and of growth factors which preside over the synthesis of new collagen.1 Finally, exposure to UV radiation, even at low doses insufficient to cause erythema, may damage Langerhans cells and establish an immunosuppressive state in the skin.2 

Glycerine preparation of Buddleja davidii stem cells 

The study presented herein was devised to examine the potential of a cosmetic ingredient obtained from Buddleja davidii cell cultures (‘Buddleja davidii stems G’ produced by IRB, Italy) in the prevention and protection of the skin from photodamage caused by exposure to UV rays. Buddleja davidii is a shrub belonging to the Scrophulariaceae family. It is native to Eastern Asia but is widespread in Europe, mainly as an ornamental plant. In fact, its conspicuous fragrant white, pink, lilac or purple flowers (Fig. 1), which attract continual visits from butterflies, have earned it the common name of “butterfly bush”. In traditional medicine, plants of the Buddleja genus are known for their cicatrising and anti-bacterial properties. The cosmetic ingredient used in the present experimental and clinical tests was obtained via a biotechnological process of cell cultures derived from plant meristematic cells or stem cells. The cell culture was performed in a controlled and completely sterile environment, thereby ensuring that the products of this process were highly standardised in composition and completely free of environmental contaminants, for example heavy metals, pesticides and aflatoxins. Furthermore, as the plant biomass required for this procedure is obtained by in vitro fermentation, harvesting or intensive farming of plant material is unnecessary, thus markedly reducing the environmental impact with respect to traditional means of cultivation. Meristematic cells are mainly found in the buds and root tips of plants, where they allow plant growth via the formation of new tissues, although this germinal state can also be reactivated in response to tissue damage such as cuts, thereby permitting the repair of damaged plant tissue.3,4 Due to their location in the delicate but vital tissues of the plant, namely the growing tips, meristematic cells are particularly rich in active substances produced in response to various types of environmental stress, for example UV radiation and attack by insects. The plant cell culture technology developed by IRB is able to orientate the production of these protective substances; indeed, in Buddleja davidii cell cultures, a series of substances belonging to this defensive apparatus has been identified, specifically members of the phenylpropanoid family: verbascoside, isoverbascoside, martinoside and leucosceptoside A.5,6 Verbascoside (Fig. 2), is the most abundant of these chemical substances, and may be found in very high concentrations in Buddleja davidii cultures. The biological properties of verbascoside, also known as acteoside, have been described in the literature and comprise a wide spectrum of activities including anti-  oxidant, anti-inflammatory, photoprotective and chelating actions. In particular, Aleo et al.7 documented a significant anti-oxidant effect of verbascoside in an experimental study comparing numerous natural antioxidant substances, in which verbascoside, obtained from cell cultures, distinguished itself for its elevated activity, irrespective of the method of determination employed. A significant anti-oxidant capacity is an essential property to guarantee the protective efficacy against cellular and tissue damage caused by UV radiation. In fact, verbascoside, obtained from Buddlejia scordioides extract, applied to the skin in vivo at a concentration of 2 mg/cm2, provided a considerable protective barrier, equivalent to SPF 26, against the harmful action of a dose of UVB radiation (312 nm, intensity 600 mJ/ cm2) applied for a time sufficient to induce the appearance of erythema. During the same experiment, the efficacy of verbascoside was found to be superior to that of escalol, a photoprotective agent frequently used in sun creams.8 Furthermore, the anti-inflammatory actions of verbascoside extracted from Syringa vulgaris, with particular relevance to the skin, has been confirmed by an in vitro test performed on cell cultures of primary human keratinocytes. In fact, the substance was able to significantly reduce, in a dose-dependent way, the release of pro-inflammatory chemokines, specifically IL-8, GM-CSF and IP-10, consequent to the stimulation of keratinocytes with TNF-?, either alone or in association with interferon-?.9 Finally, a recent experimental study into inflammation of the intestinal mucosa performed in vivo with extracts of Syringa vulgaris demonstrated that, in this tissue, verbascoside is able to inhibit both the activation of pro-inflammatory proteins and consequently also the enzymatic activity of two matrix metalloproteinase, MMP2 (gelatinase A, or 72-kDa collagenase type IV) and MMP9 (gelatinase B, or 92-kDa collagenase type IV), which also have significant effects on skin ageing phenomena.10 Based on these traditional and scientific premises, the biological properties of a cosmetic ingredient obtained from Buddleja davidii cell cultures was assessed.