Advancements in non-invasive skin sampling: Clinical conditions characterization via the assessment of skin surface cytokine biomarkers.

The skin is increasingly recognized as a biological active organ interacting with the immune system. Given that the epidermal skin layer actively releases various cytokines, non-invasive skin sampling methods could detect these cytokines, offering insights into clinical conditions. This study aims non-invasively measuring cytokine levels directly from the skin surface to characterize different inflammatory chronic disorders in the adult and elderly population: psoriasis, diabetes type 2, rosacea, chronic kidney disease (CKD) and aging. Cytokines IL-1ß, IL-8 and IL-10 were sampled from healthy subjects and patients aged 18-80 using skin surface wash technique. A well with sterile phosphate-buffered saline solution was placed on the skin for 30 min, and the extracted solution was collected from the well for further cytokine levels analysis using ELISA assay. Results show distinct cytokine profiles in different pathological processes, healthy controls, affected and unaffected areas. Aging was associated with increased IL-1ß, IL-8, and IL-10 levels in skin. In diabetes, IL-1ß and IL-8 levels were elevated in lesional areas, while IL-10 levels were decreased in non-lesional skin. Psoriatic lesions showed elevated levels of IL-1ß and IL-8. Rosacea patients had lower IL-10 levels in both lesional and non-lesional areas. CKD patients exhibited significantly lower IL-10 levels compared to healthy individuals. In conclusion, skin surface wash-derived cytokine profiles could serve as "alert biomarkers" for disease prediction, enabling early detection. Additionally, this method's cost-effectiveness allows pre-screening of molecules in clinical studies and holds potential as a tool for biomarkers and omics analysis, enhancing disorder characterization and disease management.

Safety evaluation of traces of nickel and chrome in cosmetics: The case of Dead Sea mud.

BACKGROUND: Metal impurities such as nickel and chrome are present in natural ingredients-containing cosmetic products. These traces are unavoidable due to the ubiquitous nature of these elements. Dead Sea mud is a popular natural ingredient of cosmetic products in which nickel and chrome residues are likely to occur. OBJECTIVE: To analyze the potential systemic and local toxicity of Dead Sea mud taking into consideration Dead Sea muds' natural content of nickel and chrome. METHODS: The following endpoints were evaluated: (Regulation No. 1223/20, 21/12/2009) systemic and (SCCS's Notes of Guidance) local toxicity of topical application of Dead Sea mud; health reports during the last five years of commercial marketing of Dead Sea mud. RESULTS AND CONCLUSIONS: Following exposure to Dead Sea mud, MoS (margin of safety) calculations for nickel and chrome indicate no toxicological concern for systemic toxicity. Skin sensitization is also not to be expected by exposure of normal healthy skin to Dead Sea mud. Topical application, however, is not recommended for already nickel-or chrome-sensitized persons. As risk assessment of impurities present in cosmetics may be a difficult exercise, the case of Dead Sea mud is taken here as an example of a natural material that may contain traces of unavoidable metals.

Non-invasive evaluation of skin cytokines secretion: an innovative complementary method for monitoring skin disorders.

In this review, a novel non-invasive approach based on skin surface wash sampling is described. Since the epidermis possesses a high metabolic activity, the secretion of various biomarkers can be exploited to develop non-invasive procedures for skin measurement to monitor disorders and to define a therapeutic strategy. Thus, we developed a method for the quantification of skin surface compounds. In this procedure, a well is placed on skin surface and is attached using an adhesive pad. Extraction buffer is introduced into the well for 30 min incubation period and the secretion of different biomarkers on skin surface can be measured: cytokines, antioxidants, peptides, RNA, DNA volatile organic compounds etc. Here, the focus is on cytokine measurement. After collecting skin samples cytokines can be quantified using ELISA assay. Since so far cytokine levels in skin have been evaluated mostly by invasive and prolonged procedures (punch biopsy, blister fluid and scrapping), employing this method has important implications, because it allows assessing cytokine amount with minimal invasion and high accuracy. We have already applied skin surface wash sampling for cytokine quantification in different clinical conditions: psoriasis, atopic dermatitis and chronic renal failure. A distinct pattern of cytokine secretion has been demonstrated for each disorder. Differences were also observed between lesional and non-lesional areas. The obtained results shed a new light on cutaneous cytokine expression in different clinical conditions. Moreover, the interplay between cytokines and other soluble compounds can give an added value in understanding the mechanism of skin pathologies.

Photo-damage protective effect of two facial products, containing a unique complex of Dead Sea minerals and Himalayan actives.

BACKGROUND: Skin appearance is badly affected when exposed to solar UV rays, which encourage physiological and structural cutaneous alterations that eventually lead to skin photo-damage. AIMS: To test the capability of two facial preparations, extreme day cream (EXD) and extreme night treatment (EXN), containing a unique complex of Dead Sea water and three Himalayan extracts, to antagonize biological effects induced by photo-damage. METHODS: Pieces of organ cultures of human skin were used as a model to assess the biological effects of UVB irradiation and the protective effect of topical application of two Extreme preparations. Skin pieces were analyzed for mitochondrial activity by MTT assay, for apoptosis by caspase 3 assay, and for cytokine secretion by solid phase ELISA. Human subjects were tested to evaluate the effect of Extreme preparations on skin wrinkle depth using PRIMOS and skin hydration by a corneometer. RESULTS: UVB irradiation induced cell apoptosis in the epidermis of skin organ cultures and increased their pro-inflammatory cytokine, tumor necrosis α (TNFα) secretion. Topical applications of both preparations significantly attenuated all these effects. Furthermore, in human subjects, a reduction in wrinkle depth and an elevation in the intense skin moisture were observed. CONCLUSIONS: The observations clearly show that EXD and EXN preparations have protective anti-apoptotic and anti-inflammatory properties that can attenuate biological effects of skin photo-damage. Topical application of the preparations improves skin appearance by reducing its wrinkles depth and increasing its moisturizing impact.

Non-invasive skin biomarkers quantification of psoriasis and atopic dermatitis: cytokines, antioxidants and psoriatic skin auto-fluorescence.

BACKGROUND: Psoriasis and atopic dermatitis (AD) are challenging to treat due to the absence of suitable monitoring procedure and their recurrences. Alteration of skin hydrophilic biomarkers (SHB) and structural elements occur in both disorders and may possess a distinct profile for each clinical condition. OBJECTIVE: To quantify skin cytokines and antioxidants non-invasively in psoriatic and in AD patients and to evaluate skin auto-fluorescence in psoriatic patients. METHODS: A skin wash sampling technique was utilized to detect the expression of SHB on psoriatic and AD patients and healthy controls. Inflammatory cytokine (TNFα, IL-1α and IL-6) levels, total antioxidant scavenging capacity and uric acid content were estimated. Additionally, measurement of the fluorescent emission spectra of tryptophan moieties, collagen cross-links and elastin cross-links were performed on psoriatic patients and healthy controls. RESULTS: Our findings demonstrate significant alterations of the SHB levels among psoriasis, AD and healthy skin. Differences were also observed between lesional and non-lesional areas in patients with psoriasis and AD. Ultra-structural changes were found in psoriatic patients both in lesional and non-lesional areas. CONCLUSION: Employing non-invasive measurements of skin wash sampling and skin auto-fluorescence might serve as complementary analysis for improved diagnosis and treatment of psoriasis and AD. Furthermore, they may serve as an additional monitoring tool for various diseases, in which skin dysfunction is involved.

Noninvasive skin measurements to monitor chronic renal failure pathogenesis.

BACKGROUND/AIMS: Cutaneous manifestations are common in hemodialysis (HD) patients with chronic renal failure (CRF). Associated with uremia, pruritus is a frequently observed symptom in CRF patients and increases with deteriorating renal function. Skin hydrophilic biomarkers (SHB) may be altered in CRF compared to healthy controls. METHODS: A noninvasive skin wash sampling technique to detect the expression of SHB, by measuring their secretion on skin surface, was used on HD patients and healthy controls. Hydrophilic antioxidants such as total antioxidant scavenging capacity (TSC) and uric acid (UA) content, and cytokine inflammatory biomarkers such as TNFα and IL-10 levels were estimated. RESULTS: Our findings demonstrate significant alterations of the SHB level between HD patients and healthy volunteers. Furthermore, such alterations of secreted SHB correlated markedly with detected changes in blood biochemistry and dermatology severity score. CONCLUSION: Skin wash sampling of SHB is a noninvasive technique that distinguishes between HD patients and healthy controls. In HD patients, SHB is associated with biochemical markers in blood and dermatologic symptom severity. This technique is also suggested, as a monitoring tool for diagnosis and treatments of various diseases, in which skin dysfunction is involved.

Cocaine induces oxidative damage to skin via xanthine oxidase and nitric oxide synthase.

BACKGROUND: Heavy cocaine abusers are known to develop adverse skin manifestations, however, a possible mechanism for such damages has not yet been proposed. OBJECTIVE: The present study was designed to investigate whether a systemic cocaine administration affects skin characteristics by elucidating modifications of reactive oxygen species (ROS) production, antioxidant defense and iNOS and XO activity. METHODS: Two models were used: an in vivo rat model (male Sabra), in which skin specimens were taken 20 days after i.p. cocaine injection (15 mg/kg) and an in vitro model based on HaCaT cells representing human keratinocytes. RESULTS: Our findings clearly showed that cocaine promoted skin oxidation via the involvement of the enzymes inducible nitric oxide synthase (iNOS) and xanthine oxidase (XO). Cocaine administration significantly increased iNOS expression in rats' skin. It also decreased total scavenging capacity (TSC), as well as reduced glutathione (GSH) and ascorbic acid (AA). HaCaT cells treatment with a cocaine concentration of 2 mM for 24 h (as was chosen by dose-response experiments) markedly enhanced superoxide radicals and peroxides formation. It also decreased TSC and GSH levels. Addition of iNOS and XO inhibitors completely abolished these findings. This study indicates for the first time that systemic cocaine administration affects skin condition, even after a long period of withdrawal. CONCLUSION: Our study therefore, suggests additional metabolic outcomes of cocaine due to its ability to enhance oxidative stress in skin.

Exposure of human keratinocytes to ischemia, hyperglycemia and their combination induces oxidative stress via the enzymes inducible nitric oxide synthase and xanthine oxidase.

BACKGROUND: Diabetes mellitus is characterized by a chronic hyperglycemia and might cause skin pathologies resulting from an ischemic insult. A variety of mechanisms have been suggested for the damage provided by ischemia-reperfusion injury (IRI) or for hyperglycemic conditions. Yet, the association between IRI and hyperglycemia together in skin has been poorly investigated even thought they are both present in diabetic patients. OBJECTIVE: To examine the effect of a dual stress combining IRI and hyperglycemia on human keratinocytes-its ability to cause oxidative damage and inflammatory response via the enzymes xanthine oxidase (XO) and inducible nitric oxide synthase (iNOS). METHODS: HaCaT cells were used as a model to induce IRI and hyperglycemia. In order to assess the oxidative damage, total antioxidant scavenging capacity (TSC) and GSH/GSSG ratio were evaluated. iNOS expression was evaluated and its metabolite nitric oxide was estimated by measuring nitrite levels. XO activity was assessed by uric acid quantification and by superoxide radical formation. Inflammatory response was determined through interleukin-6 secretion. RESULTS: Our observations demonstrate different responses of the cells exposed to single stress (IRI) compared to dual stress combining also hyperglycemia. However, cells response exhibited similarity during reperfusion, by enhancing iNOS expression as well as superoxide levels. While ischemia led to changes in TSC and redox state, reperfusion restored them to basal levels. IRI also caused the enhancement of secreted IL-6 and uric acid levels. CONCLUSION: iNOS and XO play a major role in IRI and hyperglycemia. Inhibition of one of these enzymes may be beneficial to skin cells under these conditions.