A polar head and an apolar tail chemically characterize surfactants, they show different properties and are categorized by different factors such as head charge and molecular weight. They work by reducing the surface tension between oil and water phases to facilitate the formation of one homogeneous mixture. In this respect, they represent unavoidable ingredients, their main application is in the production of detergents, one of if not the most important categories of cosmetics. Their role is very important, it should be remembered that it was precisely soaps and hygiene that defeated the main infectious diseases at the beginning of the last century. Due to their positive environmental impact, the potential uses of microbial sourced surfactants are actively investigated. These compounds are produced with different mechanisms by microorganisms in the aims to defend themselves from external threats, to improve the mobility in the environment, etc. In the cosmetic field, biosurfactants, restricted in the present work to those described above, can carry high advantages, in comparison to traditional surfactants, especially in the field of sustainable and safer approaches. Besiede this, costs still remain an obsatcle to their diffusion; in this regard, exploration of possible multifunctional actions could help to contain application costs. To highlight their features and possible multifunctional role, on the light of specific biological profiles yet underestimated, we have approached the present review work.

Differentiation of mesenchymal stem cells (MSCs) to hepatocytes-like cells is associated with alteration in the level of reactive oxygen species (ROS) and antioxidant defense system. Here, we report the role of glutathione in the functions of hepatocytes derived from MSCs. The stem cells undergoing differentiation were treated with glutathione modifiers [buthionine sulfoxide (BSO) or N-acetyl cysteine (NAC)], and hepatocytes were collected on day 14 of differentiation and analysed for their biological and metabolic functions. Differentiation process has been performed in presence of glutathione modifiers viz. BSO and NAC. Depending on the level of cellular glutathione, the proliferation rate of MSCs was affected. Glutathione depletion by BSO resulted in increased levels of albumin and ROS in hepatocytes. Whereas, albumin and ROS were inhibited in cells treated with glutathione precursor (NAC). The metabolic function of hepatocytes was elevated in BSO-treated cells as judged by increased urea, transferrin, albumin, alanine transaminase and aspartate transaminase secretions in the media. However, the metabolic activity of the hepatocytes was inhibited when glutathione was increased by NAC. We conclude that the efficiency of metabolic function of hepatocytes is inversely related to the levels of cellular glutathione. These data may suggest a novel role of glutathione in regulation of metabolic function of hepatocytes.

Silymarin, a mixture of flavonolignans, is extracted from milk thistle (Silybum marianum) and has a strong antioxidant activity and exhibits anticarcinogenic, anti-inflammatory, and cytoprotective effects. In this study we attempted to determine whether silymarin and the glutathione modifiers, buthionine sulfoxamine (BSO) and N-acetylcysteine (NAC), are involved in regulation of cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) in proliferating mesenchymal stem cells (MSCs). Cellular glutathione was manipulated during a 14-day culture using BSO, NAC and silymarin. At intervals of 2, 7 and 14 days, cells were collected and COX-2 and iNOS levels were measured. In parallel, generation of cellular H(2)O(2) and glutathione were measured. Supplementation of the culture media with BSO caused a dose-dependent decrease in MSC proliferation, whereas NAC or silymarin elevated the proliferation (p < 0.05). Treatment of MSC with NAC or silymarin caused a significant decrease in COX-2 levels. However, COX-2 levels in cells treated with high levels of NAC (1.0 mM) were significantly lower than those in MSCs treated with high levels of silymarin (100 μM). BSO (1.0 and 5.0 μM) caused a significant increase in COX-2 on days 2, 7 and 14. BSO caused a significant increase in iNOS, whereas NAC or silymarin decreased cellular iNOS. Overall result show that glutathione, iNOS and COX-2 in proliferating MSCs are affected by silymarin treatment. It appears that glutathione is the main target of silymarin, and in consequence iNOS and COX-2 are affected in response to silymarin treatment.

Cutaneous stem cells, gained great attention in the field of regenerative medicine as a potential therapeutic target for the treatment of skin and hair disorders and various types of skin cancers. Cutaneous stem cells play a key role in several processes like the renovation of skin structures in the condition of homeostasis and after injuries, the hair follicle growth and the reconstruction and production of melanocytes. Thus, gaining effective access to skin stem cells for therapeutic interventions that often involve active molecules with non-favorable characteristics for skin absorption is a valuable achievement. The topical route with high patient compliance and several other benefits is gaining increasing importance in basic and applied research. However, the major obstacle for topical drug delivery is the effective barrier provided by skin against penetration of the vast majority of exogenous molecules. The research in this field is focusing more and more on new strategies to circumvent and pass this barrier effectively. In this article the existing approaches are discussed considering physical and chemical methods along with utilization of novel drug delivery systems to enhance penetration of drugs to the skin. In particular, attention has been paid to studies finalized to the delivery of molecules to cutaneous stem cells with the aim of transferring signals, modulating their metabolic program, inducing physiological modifications and stem cell gene therapy.