Noninvasive Biophysical Methods Research Articles

Phytochemical profiling of Avena sativa for phytoantioxidants compounds with their multidirectional non-invasive investigation for anti-pigmenting and facial skin fatiguing effect with a stable emulgel formulation.

Objective: The current research work was initiated to develop stable Emulgel formulation loaded with natural phenolic compounds from Avena sativa that were extracted with various solvents. Method: The free radical scavenging and tyrosinase inhibition activities were performed in order to observe the effects of phenols and flavonoids in emulgel formulation on healthy human volunteers with non-invasive biophysical methods. Results: The results of the study revealed that ethanolic fraction of Avena sativa accommodate high amount of phenolic acids (147.1135 μg/mg dry powder extract) and flavonoids (161.6374 μg/mg dry powder extract) contents with extraordinary high mushroom tyrosinase (63.651 mg/ml)) inhibition and free radical scavenging (85.39 1mg/mL) potential. The developed formulation loaded with phenolic compounds potentially enhance stratum corneum hydration level, increase collagen synthesis, decrease melanin from melanocytes and oil secretions from sebaceous glands at 0.05 level of significance. Conclusion: The presence of useful phytoantioxidants in Avena sativa results in polishing of mechanical features of skin with reduced levels of roughness, scaliness, smoothness, and wrinkles of photo-aged skin. The investigator attributed that anti-aging activity is related to polyphenols present in extract; as the phenolics have the capability to quench reactive oxygen species.

Diabetic skin and UV light: Protection by antioxidants

Non-invasive biophysical methods were used to study the effect of antioxidant gels, which were prepared from Pinus halepensis bark extracts, vitamin C and water, on the skin of diabetic hairless mice irradiated with UV radiation of 1 and 2 minimal erythemal doses (MEDs). The calculated transepidermal water loss (TEWL) for diabetic mice was found to be fivefold higher on day 11 after irradiation, and in all cases, the TEWL values converged to their initial values on day 21. Both pinus and vitamin C gels inhibited the dehydration of the skin, while water gels did not show similar protection. At low dose of UV-irradiation (1 MED), vitamin C gels showed the best hydration, while by doubling the UV dose, pinus gels induced significant skin-protective effects. Upon irradiation, the mice treatment with pinus gel showed diminished inflammation in comparison with the other gels. Pinus also inhibited the hyperkeratosis of skin. As expected, 2 MEDs caused greater skin damage, such as inflammation, dryness, oxidative stress and rides (aging) compared to the damage induced by 1 MED.

Induction events and short-term regulation of electron transport in chloroplasts: an overview.

Regulation of photosynthetic electron transport at different levels of structural and functional organization of photosynthetic apparatus provides efficient performance of oxygenic photosynthesis in plants. This review begins with a brief overview of the chloroplast electron transport chain. Then two noninvasive biophysical methods (measurements of slow induction of chlorophyll a fluorescence and EPR signals of oxidized P700 centers) are exemplified to illustrate the possibility of monitoring induction events in chloroplasts in vivo and in situ. Induction events in chloroplasts are considered and briefly discussed in the context of short-term mechanisms of the following regulatory processes: (i) pH-dependent control of the intersystem electron transport; (ii) the light-induced activation of the Calvin-Benson cycle; (iii) optimization of electron transport due to fitting alternative pathways of electron flow and partitioning light energy between photosystems I and II; and (iv) the light-induced remodeling of photosynthetic apparatus and thylakoid membranes.

Association between dietary factors and human skin conditions in healthy subjects

Dietary factors have a major role in the maintenance of healthy human skin, but little information is known on the modulating effects of nutritional factor on the skin condition of human. To evaluate whether dietary factors are associated with the skin condition of humans. This study was conducted in which data on dietary intake of nutritional factors, and the hydration, sebum, pH and melanin‐elastin of skin were obtained from 136 healthy subjects. Dietary intake was assessed dietary habit, food‐frequency and food preference questionnaires. Skin condition was measured with the use of noninvasive biophysical methods. Also, samples of stratum corneum (SC) layer were obtained of the subjects by the tape stripping technique, and ceramides (Cer) quantitative analysis by high performance liquid chromatography. Multiple regression analysis was used to evaluate associations of SC Cer level and dietary factors with skin conditions. After adjustment for potential confounder factors such as sex, age, and smoking, significant associations were shown in the subjects between dietary groups of cereals and meat&fish, and Cer level and skin hydration and surface pH between the dietary groups of fat oil and beverages and skin hydration. Several associations between dietary factors and skin condition were exert observed indication that changes in dietary habit or dietary intake status may affect human skin condition.

Scientific characterization of subclinical skin changes by noninvasive biophysical methods for development of more efficacious skincare products

In 1966, after finishing only my first year of a residency program, I went to the US to study for 2.5 years with Dr Albert M. Kligman the analysis of functional properties of various skin changes in vivo using aged skin, various types of dermatitis and topically applied steroid‐induced atrophy as experimental models. Ten years later, I luckily found that measurements of high frequency conductance and capacitance of the skin enable us to evaluate the skin surface hydration state that determines the softness and smoothness of the skin and in particular to detect even subtle skin changes induced by changes in our environmental or by the application of skincare products and cosmetics. Employing such noninvasive biophysical instruments, I have analyzed the functional properties of normal and abnormal skin changes including subclinical skin changes such as atopic xerosis, senile xerosis, scars and effects of various topical and systemic agents. From these studies it became apparent that as long as a certain level of barrier function was retained skin surface hydration is a more important factor for enjoying a good quality of life. We also succeeded in confirming the effect of corneotherapy, the term so pertinently suggested by Dr Kligman for the beneficial effects of skincare products. We could show that their daily application definitely improves the condition of subclinical skin problems. Further progress in such instrumental analysis of skin properties will greatly aid us in the future in selecting a more desirable skincare product on an individual basis.

Sequential application of cold and sodium lauryl sulphate decreases irritation and barrier disruption in vivo in humans

Irritant contact dermatitis (ICD) is one of the most frequent types of occupational dermatitis. Different factors are involved in the development of contact dermatitis. In the food-processing industry, the combined exposure to different irritants may be involved in the development of ICD. Few data have been published regarding the irritant potential of sodium lauryl sulphate (SLS) in combination with cold. The present study was intended to analyse whether cold exposure and low skin temperature influence the development of ICD. Twenty (part I) and 12 (part II) healthy volunteers were exposed twice daily for 4 days to SLS alone, different low temperatures alone (4 degrees C six times for 90 s with an interval of 20 s or 15 degrees C for 10 min) or a combination of cold and SLS (19.6 microL SLS 1% cm(-2), part I; or 52.6 microL SLS 0.5% cm(-2), part II) using the tandem repetitive irritation test. Irritant cutaneous reactions were measured by noninvasive biophysical methods with transepidermal water loss as a parameter for permeability barrier function and skin colour reflectance together with visual scoring as parameters for inflammatory reactions. Cold alone caused no significant skin reaction compared with untreated control. Exposure to SLS alone and SLS together with cold (independent of the applied temperature of 4 or 15 degrees C) twice daily induced a clear irritant reaction and barrier disturbance. Reactions did not differ whether SLS was applied before or after cold. Furthermore, 'tandem application' of cold and SLS diminished the barrier disruption and irritant reaction compared with SLS alone. We conclude that the application of cold may have a protective effect on the development of ICD, at least in our short-term model.

Noninvasive biophysical methods to characterize structural changes in photodamaged human facial skin

Noninvasive biophysical methods to characterize structural changes in photodamaged human facial skin

Functional Analysis of the Stratum corneum of Patients with Atopic Dermatitis: Comparison with Psoriasis vulgaris

Background: The skin of patients with atopic dermatitis (AD) is known to have a defective barrier function of the stratum corneum (SC) that facilitates the induction of unique skin hypersensitivity to various environmental allergens and irritants. However, it has not been determined whether there are characteristics unique to AD, because an apparently similar dysfunction of the SC is also observable in other inflammatory dermatoses such as psoriasis. Objective: Our purpose was to analyze the SC functions of patients with AD in comparison with those with psoriasis, an endogenously induced immune-mediated dermatosis. Methods: We conducted functional analyses of the lesional and nonlesional skin of AD and psoriasis patients by using noninvasive biophysical methods. Results: When we classified their skin changes into several subtypes based on the clinical features, we found that a severity-dependent disruption in the barrier function as well as a decrease in the SC hydration occurred in both dermatoses and to a similar degree. The extent of their SC barrier damage on the skin of the trunk and limbs was almost comparable to that of normal facial skin of healthy individuals. We also found similarly small, immature corneocytes that are associated with epidermal hyperproliferation accompanied by poor differentiation in both dermatoses. Moreover, we found similar but much milder SC functional abnormalities in the nonlesional skin where the extent of the dysfunction was much closer to that of healthy skin than to that of lesional skin. Conclusion: From these data, we could not find any differences in the functional abnormalities of the SC of AD patients that would justify considering it to be a unique dermatosis at least in terms of barrier damage. Because the presence of smaller corneocytes reflects the active proliferation of the underlying epidermis, we think that the barrier impairment and deficient water-holding capacity of the SC develop as a result of the enhanced epidermal proliferation in both dermatoses that is caused by the underlying inflammation.

Development of noninvasive and quantitative methodologies for the assessment of chronic ulcers and scars in humans.

Chronic ulcers are a significant and common cause of morbidity and mortality worldwide. They disrupt the epidermis and dermis, resulting in a loss of barrier function. Keloids and hypertrophic scars (benign cutaneous tumors) represent an abnormal healing response. These fibroproliferative disorders are characterized by an overabundance of collagen and accumulation of extracellular matrix due to an imbalance between synthesis and degradation, culminating in excessive scarring. The objectives of this study were to evaluate and compare noninvasive biophysical methods for the measurement of outstanding quantitative parameters of scars and chronic ulcers, and to establish correlations between the parameters measured and the results of conventional subjective clinical evaluations. The development of new technologies, based on ultrasonography and laser Doppler, makes possible new dermatological evaluation methods. Fifteen patients (6 females and 9 males) with 15 chronic ulcers (4 diabetic ulcers, 10 venous ulcers and 1 pressure ulcer) and 30 patients (19 females and 11 males) with 30 scars (25 hypertrophic and 5 keloids) were included in this study. Clinical evaluation was performed by a dermatologist, an aesthetic surgeon and an endocrinologist. Biophysical measurements were used to assess local blood flow by laser Doppler flowmetry (Moor DRT4), thickness and echogenicity by high frequency ultrasonography (20 MHz, Dermascan C) and ulcer linear dimensions by image analysis. Our results show that blood flow within the ulcers and scars was higher than within normal skin. Also, skin thickness of chronic ulcers was decreased when compared to normal skin; the thickness of hypertrophic scars, but not of keloids, was increased in comparison to normal skin, and presented the possibility of measuring wound and scar surfaces with precision. In summary, this pilot study established the feasibility of measuring various biophysical parameters and adapted their potential utility to research on wounds.

Non-invasive quantification of skin injury resulting from exposure to sulphur mustard and Lewisite vapours

The severity and progression of skin lesions resulting from exposure to the chemical warfare agents Lewisite (L) and sulphur mustard (SM) have been investigated using the non-invasive biophysical methods of evaporimetry and reflectance spectroscopy in large white pigs in vivo. Erythema (redness) expressed immediately after exposure to L or SM vapours appeared to be related to the lesion severity as demonstrated by histopathological analysis. Skin brightness correlated well with scab formation whereas blueness (cyanosis) did not appreciably alter throughout the study. Rates of transepidermal water loss (TEWL) changed both with occlusion (during vapour exposure) and also mirrored the progression of macroscopic skin injury after 12 h. Whilst no single parameter could be used in isolation to ascertain the severity and subsequent progression of the skin lesions, measurement of erythema, skin brightness and TEWL could provide quantitative, non-invasive methods for determining the efficacy of antidotes or therapies to prevent the toxic effects of chemical warfare agents. However, neither colourimetry or TEWL provided a clinical evaluation of such lesions that were comparable with the prognostic capabilities of laser Doppler imaging.

Clinical and biophysical studies of the skin in renal allograft patients

The skin of 60 recipients of cadaveric kidney grafts was studied from 6 months to 10 years after transplantation using both clinical grading and noninvasive biophysical methods. Results were compared with those obtained in a group of healthy volunteers, similar with regard to age and sex. The main result of this study is that skin thickness is already significantly decreased 6 months after transplantation and reaches its lowest value after 1 yr. The number of corneocytes harvested from transplant recipients appears to be higher than that obtained in normal controls, whatever their age. Our study demonstrates that permanent steroid therapy is responsible for the dermic and epidermic changes observed in transplant recipients receiving long‐term treatment.