Infrared radiation induces the p53 signaling pathway: role in infrared prevention of ultraviolet B toxicity

Reducing Carbon Dioxide Laser-Induced Postinflammatory Hyperpigmentation with Prophylactic Photobiomodulation: A Case Study

Objective: This study aimed to investigate the effectiveness of prophylactic photobiomodulation (PBM) in reducing postinflammatory hyperpigmentation (PIH) induced by carbon dioxide (CO2) laser resurfacing in a patient with periorbital syringomas. Background: PIH is a common condition characterized by abnormal skin pigmentation after an inflammatory process occurring in up to 20-30% of patients undergoing CO2 laser resurfacing. Methods: The patient was treated with PBM using a pulsed home-use device at 630 nm before and after CO2 laser treatment. The patient was asked to treat the right periorbital area before and after the CO2 laser treatment, which was continued once a day for 2 consecutive weeks. Results: At 12 weeks, PIH was significantly reduced on the treated side compared with the contralateral untreated side (leading to persistent erythema at 6 months). Conclusions: This is the first report of prophylactic treatment of CO2 laser-induced dyschromia using PBM.

Skin Protection by Carotenoid Pigments

Sunlight, despite its benefits, can pose a threat to the skin, which is a natural protective barrier. Phototoxicity caused by overexposure, especially to ultraviolet radiation (UVR), results in burns, accelerates photoaging, and causes skin cancer formation. Natural substances of plant origin, i.e., polyphenols, flavonoids, and photosynthetic pigments, can protect the skin against the effects of radiation, acting not only as photoprotectors like natural filters but as antioxidant and anti-inflammatory remedies, alleviating the effects of photodamage to the skin. Plant-based formulations are gaining popularity as an attractive alternative to synthetic filters. Over the past 20 years, a large number of studies have been published to assess the photoprotective effects of natural plant products, primarily through their antioxidant, antimutagenic, and anti-immunosuppressive activities. This review selects the most important data on skin photodamage and photoprotective efficacy of selected plant carotenoid representatives from in vivo studies on animal models and humans, as well as in vitro experiments performed on fibroblast and keratinocyte cell lines. Recent research on carotenoids associated with lipid nanoparticles, nanoemulsions, liposomes, and micelles is reviewed. The focus was on collecting those nanomaterials that serve to improve the bioavailability and stability of carotenoids as natural antioxidants with photoprotective activity.

The effects of infrared radiation on the human skin

BACKGROUND

Infrared radiation (IR) is the portion of the electromagnetic spectrum between visible light (VL) and microwaves, with wavelengths between 700 nm and 1 mm. Humans are mainly exposed to ultraviolet (UV) radiation (UVR) and IR through the sun. Unlike UVR which is well known for its carcinogenic properties, the relationship between IR and skin health has not been as extensively studied; as such, we gather the available published evidence here to better elucidate this relationship.

METHODS

Several databases including Pubmed, Google Scholar, and Embase were searched for articles relating to infrared radiation and the skin. Articles were selected for their relevance and novelty.

RESULTS

Detrimental effects such as thermal burns, photocarcinogenesis, and photoaging have been reported, though evidence suggests that these may be due to the thermal effects produced secondary to IR exposure rather than the isolated effect of IR. There are currently no chemical or physical filters specifically available for protection against IR, and existing compounds are not known to have IR-filtering capacity. Interestingly, IR may have some photoprotective properties against the carcinogenic effects of UVR. Furthermore, IR has been used with encouraging results in skin rejuvenation, wound healing, and hair restoration when given at an appropriate therapeutic dose.

CONCLUSION

A better understanding of the current landscape of research surrounding IR can help illuminate its effects on the skin and highlight areas for further research. Here, we review relevant data on IR to assess its deleterious and beneficial effects on human skin, along with possible means for IR photoprotection.

Biodegradable mesoporous nanocomposites with dual-targeting function for enhanced anti-tumor therapy

Tumor-associated macrophages (TAMs), the main components of infiltrating leukocytes in tumors, often play a key role in promoting cancer development and progression. The tumor-specific microenvironment forces the phenotype of tumor-infiltrating to evolve in a direction favorable to tumor development, that is, the generation of M2-like TAMs. Consequently, the dual intervention of cancer cells and tumor microenvironment has become a research hotspot in the field of tumor immunotherapy. In this contribution, we developed pH-sensitive mesoporous calcium silicate nanocomposites (MCNs) encapsulated with indocyanine green (ICG) to enable the effective combination of photothermal therapy (PTT) and photodynamic therapy (PDT) triggered by the 808 nm near-infrared (NIR) light. The mannose and hyaluronic acid-grafted MCNs specifically targeted TAMs and tumor cells and promoted cell apoptosis both in vitro and in vivo. This paper revealed that irradiation of ICG loaded MCNs with NIR can produce a potent hyperthermia and induce abundant intracellular singlet oxygen generation in the target cells. These results suggest that the novel nanoplatform is believed to facilitate the delivery of chemotherapeutic agents to the tumor microenvironment (TME) to enhance the effects of tumor treatment.

Perspective: Water-Filtered Infrared-A-Radiation (wIRA) - Novel Treatment Options for Chlamydial Infections?

Water-filtered infrared-A-radiation (wIRA) is a promising therapeutic method, which is particularly used as supportive treatment for wound closure, and wound infection treatment and prevention. High penetration properties of the heat field and beneficial effects on wound healing processes predispose wIRA irradiation to be a non-invasive treatment method for bacterial infections in superficial tissues. Since Chlamydia trachomatis still represents the leading cause of infectious blindness in third world countries (WHO http://www.who.int/topics/trachoma/en/) and wIRA displays beneficial effects on chlamydial infections in vitro without inducing cellular damage in ex vivo eye models and also shows beneficial effects on wound healing, this irradiation technique might represent a promising future treatment for trachoma patients. To this end, further studies investigating shorter irradiation times or irradiation of Chlamydia in chronic infections [the chlamydial stress response (Bavoil, 2014)] as well as safety studies in animal models should clearly be performed.

Impact of infrared radiation on UVB-induced skin tumourigenesis in wild type C57BL/6 mice

Additional exposure to infrared radiation leads to a more aggressive phenotype of UVB-induced skin tumours in wild type mice.

Development of an in vitro Test Procedure to Determine the Direct Infrared A Protection of Sunscreens and Non-Cosmetic Samples

BACKGROUND

Every day human skin is exposed to infrared A (IRA) radiation as part of the natural sun rays. As IRA radiation accounts for around one third of the solar radiation, it has gained great attention concerning its effects on the human body and skin. In the past few years it has been discussed controversially whether IRA radiation (of solar origin) is harmful or not. Nonetheless, there are several sunscreens on the German market that claim IRA protection for themselves.

AIMS

The present study seeks to find an experimental set-up and a test procedure for the determination and quantification of direct IRA protection (realized via reflection or absorption of the IRA radiation), since to our knowledge these do not yet exist.

METHODS

In this study we proved the usability of a set-up consisting of a light source, an IRA-transmissible filter system and a sensor unit, for the determination and quantification of the IRA protection of cosmetic and non-cosmetic samples.

RESULTS/CONCLUSION

The applicability of the IRA emission of the light source, the spectral detector, transmissivity of the filter systems and the sample carriers could be validated. This experimental set-up can be used as an in vitro test procedure for the determination of direct IRA protection.

[LED lights in dermatology]

The use in dermatology of light-emitting diodes (LEDs) continues to be surrounded by controversy. This is due mainly to poor knowledge of the physicochemical phases of a wide range of devices that are difficult to compare to one another, and also to divergences between irrefutable published evidence either at the level of in vitro studies or at the cellular level, and discordant clinical results in a variety of different indications: rejuvenation, acne, wound healing, leg ulcers, and cutaneous inflammatory or autoimmune processes. Therapeutic LEDs can emit wavelengths ranging from the ultraviolet, through visible light, to the near infrared (247-1300 nm), but only certain bands have so far demonstrated any real value. We feel certain that if this article remains factual, then readers will have a different, or at least more nuanced, opinion concerning the use of such LED devices in dermatology.

Heat for wounds - water-filtered infrared-A (wIRA) for wound healing - a review

Background: Water-filtered infrared-A (wIRA) is a special form of heat radiation with high tissue penetration and a low thermal load to the skin surface. wIRA corresponds to the major part of the sun’s heat radiation, which reaches the surface of the Earth in moderate climatic zones filtered by water and water vapour of the atmosphere. wIRA promotes healing of acute and chronic wounds both by thermal and thermic as well as by non-thermal and non-thermic cellular effects.

Methods: This publication includes a literature review with search in PubMed/Medline for “water-filtered infrared-A” and “wound”/”ulcus” or “wassergefiltertes Infrarot A” and “Wunde”/”Ulkus”, respectively (publications in English and German), and additional analysis of study data. Seven prospective clinical studies (of these six randomized controlled trials (RCT), the largest study with n=400 patients) were identified and included. All randomized controlled clinical trials compare a combination of high standard care plus wIRA treatment vs. high standard care alone. The results below marked with “vs.” present these comparisons.

Results:

wIRA increases tissue temperature (+2.7°C at a tissue depth of 2 cm), tissue oxygen partial pressure (+32% at a tissue depth of 2 cm) and tissue perfusion (effect sizes within the wIRA group).

wIRA promotes normal as well as disturbed wound healing by diminishing inflammation and exudation, by promotion of infection defense and regeneration, and by alleviation of pain (with respect to alleviation of pain, without any exception during 230 irradiations, 13.4 vs. 0.0 on a visual analogue scale (VAS 0–100), median difference between groups 13.8, 95% confidence interval (CI) 12.3/16.7, p<0.000001) with a substantially reduced need for analgesics (52–69% less in the three groups with wIRA compared to the three control groups in visceral surgery, p=0.000020 and 0.00037 and 0.0045, respectively; total of 6 vs. 14.5 analgesic tablets on 6 surveyed days (of weeks 1–6) in chronic venous stasis ulcers, median difference –8, 95% CI –10/–5, p=0.000002).

Further effects are:

Faster reduction of wound area (in severely burned children: 90% reduction of wound size after 9 vs. 13 days, after 9 days 89.2% vs. 49.5% reduction in wound area, median difference 39.5% wound area reduction, 95% CI 36.7%/42.2%, p=0.000011; complete wound closure of chronic venous stasis ulcers after 14 vs. 42 days, median difference –21 days, 95% CI –28/–10, p=0.000005).

Better overall evaluation of wound healing (surgical wounds: 88.6 vs. 78.5 on a VAS 0–100, median difference 8.9, 95% CI 6.1/12.0, p<0.000001).

Better overall evaluation of the effect of irradiation (79.0 vs. 46.8 on a VAS 0–100 with 50 as neutral point, median difference 27.9, 95% CI 19.8/34.6, p<0.000001).

Higher tissue oxygen partial pressure during irradiation with wIRA (at a tissue depth of 2 cm 41.6 vs. 30.2 mmHg, median difference 11.9 mmHg, 95% CI 9.6/14.2 mmHg, p<0.000001).

Higher tissue temperature during irradiation with wIRA (at a tissue depth of 2 cm 38.9 vs. 36.4°C, median difference 2.6°C, 95% CI 2.2/2.9°C, p<0.000001).

Better cosmetic result (84.5 vs. 76.5 on a VAS 0–100, median difference 7.9, 95% CI 3.7/12.0, p=0.00027).

Lower wound infection rate (single preoperative irradiation: 5.1% vs. 12.1% wound infections in total, difference –7.0%, 95% CI –12.8%/–1.3%, p=0.017, of these: late wound infections (postoperative days 9-30) 1.7% vs. 7.7%, difference –6.0%, 95% CI –10.3%/–1.7%, p=0.007).

Shorter hospital stay (9 vs. 11 postoperative days, median difference –2 days, 95% CI –3/0 days, p=0.022).

Most of the effects have been proven with an evidence level of 1a or 1b.

Conclusion: Water-filtered infrared-A is a useful complement for the treatment of acute and chronic wounds.

Infrared and skin: Friend or foe

In the last decade, it has been proposed that the sun's IR-A wavelengths might be deleterious to human skin and that sunscreens, in addition to their desired effect to protect against UV-B and UV-A, should also protect against IR-A (and perhaps even visible light). Several studies showed that NIR may damage skin collagen content via an increase inMMP-1 activity in the same manner as is known for UVR. Unfortunately, the artificial NIR light sources used in such studies were not representative of the solar irradiance. Yet, little has been said about the other side of the coin. This article will focus on key information suggesting that IR-A may be more beneficial than deleterious when the skin is exposed to the appropriate irradiance/dose of IR-A radiation similar to daily sun exposure received by people in real life.IR-A might even precondition the skin--a process called photo prevention--from an evolutionary standpoint since exposure to early morning IR-A wavelengths in sunlight may ready the skin for the coming mid-day deleterious UVR. Consequently IR-A appears to be the solution, not the problem. It does more good than bad for the skin. It is essentially a question of intensity and how we can learn from the sun. © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Effect of infrared radiation A on photoaged hairless mice harboring eumelanin and pheomelanin in the epidermis

Infrared radiation A (IRA) is absorbed by melanin and generates heat. Therefore, the effect of IRA could be well analyzed using skin, which contains melanin in the epidermis. Hairless mice harboring epidermal melanocytes that produce eumelanin, pheomelanin, or non-melanin were generated by backcrossing K14-stem cell factor mice, recessive yellow mice, and then albino hairless mice. High-dose IRA was irradiated over 18 weeks after the establishment of photoaged mice by irradiation with ultraviolet B (UVB) three times a week for 14 weeks. Tumor formation was assessed every week. The formation of cyclobutane pyrimidine dimer and apoptotic cells by the irradiation of IRA and UVB was evaluated. Repetitive irradiation of IRA did not promote tumor formation in all types of mice. Pre-irradiation of IRA to UVB, but not post-irradiation, accelerated the elimination of cyclobutane pyrimidine dimers and enhanced apoptosis; these effects were most obvious in eumelanin-producing mice. Real-time polymerase chain reaction analysis showed downregulation of FLICE (cellular caspase 8)-like inhibitory protein and B-cell lymphoma-extra large and upregulation of Bcl-2-associated X protein by UVB, but further enhancement of these molecules by pre-irradiation of IRA was not observed. These results indicate that IRA does not confer the promotion of UVB-induced carcinogenesis in photoaged mice harboring epidermal melanocytes and that photochemical reaction between IRA and melanin might be involved in the induction of apoptosis and the elimination of cyclobutane pyrimidine dimers by UVB. The enhancement of apoptosis by pre-irradiation of IRA to UVB might be induced by mechanisms other than the modification of the mRNA expression of FLICE (cellular caspase 8)-like inhibitory protein, B-cell lymphoma-extra large, and Bcl-2-associated X.

Effects of water-filtered infrared-A and of heat on cell death, inflammation, antioxidative potential and of free radical formation in viable skin--first results

The effects of water-filtered infrared-A (wIRA) and of convective heat on viability, inflammation, inducible free radicals and antioxidative power were investigated in natural and viable skin using the ex vivo Bovine Udder System (BUS) model. Therefore, skin samples from differently treated parts of the udder of a healthy cow were analyzed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test, by prostaglandin E2 (PGE2) measurement and by electron spin resonance (ESR) spectroscopy. Neither cell viability, the inflammation status, the radical status or the antioxidative defence systems of the skin were significantly affected by wIRA applied within 30 min by using an irradiance of 1900 W m(-2) which is of relevance for clinical use, but which exceeded the maximum solar IR-A irradiance at the Earth's surface more than 5 times and which resulted in a skin surface temperature of about 45 °C without cooling and of about 37 °C with convective cooling by air ventilation. No significant effects on viability and on inflammation were detected when convective heat was applied alone under equivalent conditions in terms of the resulting skin surface temperatures and exposure time. As compared with untreated skin, free radical formation was almost doubled, whereas the antioxidative power was reduced to about 50% after convective heating to about 45 °C.

Effects of ultraviolet radiation, visible light, and infrared radiation on erythema and pigmentation: a review

The effects of ultraviolet radiation, visible light, and infrared radiation on cutaneous erythema, immediate pigment darkening, persistent pigment darkening, and delayed tanning are affected by a variety of factors. Some of these factors include the depth of cutaneous penetration of the specific wavelength, the individual skin type, and the absorption spectra of the different chromophores in the skin. UVB is an effective spectrum to induce erythema, which is followed by delayed tanning. UVA induces immediate pigment darkening, persistent pigment darkening, and delayed tanning. At high doses, UVA (primarily UVA2) can also induce erythema in individuals with skin types I-II. Visible light has been shown to induce erythema and a tanning response in dark skin, but not in fair skinned individuals. Infrared radiation produces erythema, which is probably a thermal effect. In this article we reviewed the available literature on the effects of ultraviolet radiation, visible light, and infrared radiation on the skin in regards to erythema and pigmentation. Much remains to be learned on the cutaneous effects of visible light and infrared radiation.

Restoration of tumor suppressor p53 by differentially regulating pro- and anti-p53 networks in HPV-18-infected cervical cancer cells

Abrogation of functional p53 is responsible for malignant cell transformation and maintenance of human papilloma virus (HPV)-infected cancer cells. Restoration of p53 has, therefore, been regarded as an important strategy for molecular intervention of HPV-associated malignancies. Here we report that differential regulation of pro- and anti-p53 setups not only upregulates p53 transcription but also stabilizes and activates p53 protein to ensure p53-induced apoptosis in HPV-18-infected cervical cancer. Functional restoration of p53 can be achieved by non-steroidal anti-inflammatory drug celecoxib via multiple molecular mechanisms: (i) inhibition of p53 degradation by suppressing viral oncoprotein E6 expression, (ii) promoting p53 transcription by downmodulating cycloxygenase-2 (Cox-2) and simultaneously retrieving p53 from Cox-2 association and (iii) activation of p53 via ataxia telangiectasia mutated-/p38 mitogen-activated protein kinase-mediated phosphorylations at serine-15/-46 residues. That restored p53 is functional has been confirmed by its ability of transactivating Bax and p53-upregulated modulator of apoptosis, which in turn switch on the apoptotic machinery in these cells. Studies undertaken in biopsy samples of cervical carcinoma further validated celecoxib effect. Our approaches involving gene manipulation and pharmacological interference finally highlight that celecoxib alters pro- and anti-p53 networks, not in isolation but in concert, to rejuvenate p53-dependent apoptotic program in HPV-infected cervical cancer cells.

Infrared radiation does not enhance the frequency of ultraviolet radiation-induced skin tumors, but their growth behaviour in mice

There is increasing concern about the interaction between infrared radiation (IR) and ultraviolet radiation (UVR) with regard to carcinogenesis because prolonged solar exposure is associated with an increased cumulative load not only of UVR but also of IR. We recently demonstrated that IR-pretreatment reduces UVR-induced apoptosis. As this might support the survival of UVR-damaged cells and thus carcinogenesis, we performed an in vivo photocarcinogenesis study. One group of mice were treated with IR prior to each UVR exposure; additional groups were treated with IR or UVR alone. IR alone did not induce skin cancer. UVR-induced tumor formation was not enhanced in IR-pretreated mice, but, in contrast, seemed to occur with delay. This correlated with a reduction of p53 mutated clones in the skin. However, once developed, tumors in IR-pretreated mice grew faster which was confirmed by their enhanced Ki-67 expression. The enhanced aggressiveness of tumors derived from IR-pretreated mice was associated with a higher prevalence of sarcomas than epithelial tumors. Hence, the impact of IR on UVR-induced carcinogenesis has to be interpreted with caution. Although IR may delay the onset of UVR-induced tumors, it might contribute to a worse outcome by shifting these tumors into a more aggressive phenotype.

Infrared A radiation influences the skin fibroblast transcriptome: mechanisms and consequences

Infrared A (IRA) radiation (760-1440 nm) is a major component of solar radiation and, similar to UVR, causes photoaging of human skin by increasing the expression of matrix metalloproteinase-1 in human skin fibroblasts. In this study, we assessed the IRA-induced transcriptome in primary human skin fibroblasts. Microarray analysis revealed 599 IRA-regulated transcripts. The IRA-induced transcriptome differed from changes known to be induced by UV. IRA-responsive genes include the categories extracellular matrix, calcium homeostasis, stress signaling, and apoptosis. Selected results were confirmed by real-time PCR experiments analyzing 13 genes representing these four categories. By means of chemical inhibitors of known signaling pathways, we showed that ERK1/2, the p38-, JNK-, PI3K/AKT-, STAT3-, and IL-6 as well as the calcium-mediated signaling pathways, are functionally involved in the IRA gene response and that a major part of it is triggered by mitochondrial and, to a lesser extent, non-mitochondrial production of reactive oxygen species. Our results identify IRA as an environmental factor with relevance for skin homeostasis and photoaging.

Water-filtered infrared-A (wIRA) in acute and chronic wounds

Water-filtered infrared-A (wIRA), as a special form of heat radiation with a high tissue penetration and a low thermal load to the skin surface, can improve the healing of acute and chronic wounds both by thermal and thermic as well as by non-thermal and non-thermic effects. wIRA increases tissue temperature (+2.7°C at a tissue depth of 2 cm), tissue oxygen partial pressure (+32% at a tissue depth of 2 cm) and tissue perfusion. These three factors are decisive for a sufficient supply of tissue with energy and oxygen and consequently also for wound healing and infection defense.

wIRA can considerably alleviate pain (without any exception during 230 irradiations) with substantially less need for analgesics (52–69% less in the groups with wIRA compared to the control groups). It also diminishes exudation and inflammation and can show positive immunomodulatory effects. The overall evaluation of the effect of irradiation as well as the wound healing and the cosmetic result (assessed on visual analogue scales) were markedly better in the group with wIRA compared to the control group. wIRA can advance wound healing (median reduction of wound size of 90% in severely burned children already after 9 days in the group with wIRA compared to 13 days in the control group; on average 18 versus 42 days until complete wound closure in chronic venous stasis ulcers) or improve an impaired wound healing (reaching wound closure and normalization of the thermographic image in otherwise recalcitrant chronic venous stasis ulcers) both in acute and in chronic wounds including infected wounds. After major abdominal surgery there was a trend in favor of the wIRA group to a lower rate of total wound infections (7% versus 15%) including late infections following discharge from hospital (0% versus 8%) and a trend towards a shorter postoperative hospital stay (9 versus 11 days).

Even the normal wound healing process can be improved.

The mentioned effects have been proven in six prospective studies, with most of the effects having an evidence level of Ia/Ib.

wIRA represents a valuable therapy option and can generally be recommended for use in the treatment of acute as well as of chronic wounds.

Light-emitting diodes (LEDs) in dermatology

Light-emitting diode photobiomodulation is the newest category of nonthermal light therapies to find its way to the dermatologic armamentarium. In this article, we briefly review the literature on the development of this technology, its evolution within esthetic and medical dermatology, and provide practical and technical considerations for use in various conditions. This article also focuses on the specific cell-signaling pathways involved and how the mechanisms at play can be put to use to treat a variety of cutaneous problems as a stand-alone application and/or complementary treatment modality or as one of the best photodynamic therapy light source.

Infrared radiation confers resistance to UV-induced apoptosis via reduction of DNA damage and upregulation of antiapoptotic proteins

Infrared radiation (IR) is increasingly used for wellness purposes. In this setting, it is frequently combined with UV radiation, primarily for tanning purposes. The impact of IR on UV-induced carcinogenesis is still unclear. Hence, we investigated the interplay between IR and UV with regard to UV-induced apoptosis. Pretreatment of murine keratinocytes with IR before UV reduced the apoptotic rate. Likewise, the number of sunburn cells was reduced in mice preexposed to IR before UV. The amounts of UV-induced DNA damage were reduced by IR both in vitro and in vivo. This was not observed in DNA repair-deficient mice. UV-induced downregulation of the antiapoptotic proteins FLIP(L) and BCL-X(L) was prevented by IR, whereas the proapoptotic protein BAX was downregulated. These data indicate that IR reduces UV-induced apoptosis that may be mediated by several pathways, including reduction of DNA damage and induction of antiapoptotic proteins. The antiapoptotic effects of IR may support the survival of UV-damaged cells and thus carcinogenesis. As, however, IR reduces UV-induced DNA damage, the balance between these two effects may be important. Thus, in vivo carcinogenesis studies are required to define the role of IR and its interaction with UV in photocarcinogenesis.

Improvement of wound healing by water-filtered infrared-A (wIRA) in patients with chronic venous stasis ulcers of the lower legs including evaluation using infrared thermography

BACKGROUND

Water-filtered infrared-A (wIRA) is a special form of heat radiation with a high tissue-penetration and with a low thermal burden to the surface of the skin. wIRA is able to improve essential and energetically meaningful factors of wound healing by thermal and non-thermal effects.

AIM OF THE STUDY

prospective study (primarily planned randomised, controlled, blinded, de facto with one exception only one cohort possible) using wIRA in the treatment of patients with recalcitrant chronic venous stasis ulcers of the lower legs with thermographic follow-up.

METHODS

10 patients (5 males, 5 females, median age 62 years) with 11 recalcitrant chronic venous stasis ulcers of the lower legs were treated with water-filtered infrared-A and visible light irradiation (wIRA(+VIS), Hydrosun radiator type 501, 10 mm water cuvette, water-filtered spectrum 550-1400 nm) or visible light irradiation (VIS; only possible in one patient). The uncovered wounds of the patients were irradiated two to five times per week for 30 minutes at a standard distance of 25 cm (approximately 140 mW/cm(2) wIRA and approximately 45 mW/cm(2) VIS). Treatment continued for a period of up to 2 months (typically until closure or nearly closure of the ulcer). The main variable of interest was "percent change of ulcer size over time" including complete wound closure. Additional variables of interest were thermographic image analysis, patient's feeling of pain in the wound, amount of pain medication, assessment of the effect of the irradiation (by patient and by clinical investigator), assessment of feeling of the wound area (by patient), assessment of wound healing (by clinical investigator) and assessment of the cosmetic state (by patient and by clinical investigator). For these assessments visual analogue scales (VAS) were used.

RESULTS

The study showed a complete or nearly complete healing of lower leg ulcers in 7 patients and a clear reduction of ulcer size in another 2 of 10 patients, a clear reduction of pain and pain medication consumption (e.g. from 15 to 0 pain tablets per day), and a normalization of the thermographic image (before the beginning of the therapy typically hyperthermic rim of the ulcer with relative hypothermic ulcer base, up to 4.5 degrees C temperature difference). In one patient the therapy of an ulcer of one leg was performed with the fully active radiator (wIRA(+VIS)), while the therapy of an ulcer of the other leg was made with a control group radiator (only VIS without wIRA), showing a clear difference in favour of the wIRA treatment. All mentioned VAS ratings improved remarkably during the period of irradiation treatment, representing an increased quality of life. Failures of complete or nearly complete wound healing were seen only in patients with arterial insufficiency, in smokers or in patients who did not have venous compression garment therapy.

DISCUSSION AND CONCLUSIONS

wIRA can alleviate pain considerably (with an impressive decrease of the consumption of analgesics) and accelerate wound healing or improve a stagnating wound healing process and diminish an elevated wound exudation and inflammation both in acute and in chronic wounds (in this study shown in chronic venous stasis ulcers of the lower legs) and in problem wounds including infected wounds. In chronic recalcitrant wounds complete healing is achieved, which was not reached before. Other studies have shown that even without a disturbance of wound healing an acute wound healing process can be improved (e.g. reduced pain) by wIRA. wIRA is a contact-free, easily used and pleasantly felt procedure without consumption of material with a good penetration effect, which is similar to solar heat radiation on the surface of the earth in moderate climatic zones. Wound healing and infection defence (e.g. granulocyte function including antibacterial oxygen radical formation of the granulocytes) are critically dependent on a sufficient energy supply (and on sufficient oxygen). The good clinical effect of wIRA on wounds and also on problem wounds and wound infections can be explained by the improvement of both the energy supply and the oxygen supply (e.g. for the granulocyte function). wIRA causes as a thermal effect in the tissue an improvement in three decisive factors: tissue oxygen partial pressure, tissue temperature and tissue blood flow. Besides this non-thermal effects of infrared-A by direct stimulation of cells and cellular structures with reactions of the cells have also been described. It is concluded that wIRA can be used to improve wound healing, to reduce pain, exudation, and inflammation and to increase quality of life.

Green tea extract reduces induction of p53 and apoptosis in UVB-irradiated human skin independent of transcriptional controls

Ultraviolet (UV) irradiation plays a pivotal role in human skin carcinongenesis. Preclinically, systemically and topically applied green tea extract (GTE) has shown reduction of UV-induced (i) erythema, (ii) DNA damage, (iii) formation of radical oxygen species and (iv) downregulation of numerous factors related to apoptosis, inflammation, differentiation and carcinogenesis. In humans, topical GTE has so far only been tested in limited studies, with usually very high GTE concentrations and over short periods of time. Both chemical stability of GTE and staining properties of highly concentrated green tea polyphenols limit the usability of highly concentrated green tea extracts in cosmetic products. The present study tested the utility of stabilized low-dose GTE as photochemopreventive agents under everyday conditions. We irradiated with up to 100 mJ/cm(2) of UVB light skin patches which were pretreated with either OM24-containing lotion or a placebo lotion. Biopsies were taken from both irradiated and un-irradiated skin for both immunohistochemistry and DNA microarray analysis. We found that while OM24 treatment did not significantly affect UV-induced erythema and thymidine dimer formation, OM24 treatment significantly reduced UV-induced p53 expression in keratinocytes. We also found that OM24 treatment significantly reduced the number of apoptotic keratinocytes (sunburn cells and TUNEL-positive cells). Carefully controlled DNA microarray analyses showed that OM24 treatment does not induce off-target changes in gene expression, reducing the likelihood of unwanted side-effects. Topical GTE (OM24) reduces UVB-mediated epithelial damage already at low, cosmetically usable concentrations, without tachyphylaxis over 5 weeks, suggesting GTE as suitable everyday photochemopreventive agents.

LED photoprevention: reduced MED response following multiple LED exposures

BACKGROUND AND OBJECTIVES

As photoprotection with traditional sunscreen presents some limitations, the use of non-traditional treatments to increase skin resistance to ultraviolet (UV) induced damage would prove particularly appealing. The purpose of this pilot study was to test the potential of non-thermal pulsed light-emitting diode (LED) treatments (660 nm) prior to UV exposure in the induction of a state of cellular resistance against UV-induced erythema.

STUDY DESIGN/MATERIALS AND METHODS

Thirteen healthy subjects and two patients with polymorphous light eruption (PLE) were exposed to 5, 6, or 10 LED treatments (660 nm) on an EXPERIMENTAL anterior thigh region. Individual baseline minimal erythema doses (MED) were then determined. UV radiation was thereafter performed on the LED EXPERIMENTAL and CONTROL anterior thigh areas. Finally, 24 hours post-UV irradiation, LED pre-treated MED responses were compared to the non-treated sites.

RESULTS

Reduction of erythema was considered significant when erythema was reduced by >50% on the LED-treated side as opposed to CONTROL side. A significant LED treatment reduction in UV-B induced erythema reaction was observed in at least one occasion in 85% of subjects, including patients suffering from PLE. Moreover, there was evidence of a dose-related pattern in results. Finally, a sun protection factor SPF-15-like effect and a reduction in post-inflammatory hyperpigmentation were observed on the LED pre-treated side.

CONCLUSIONS

Results suggest that LED based therapy prior to UV exposure provided significant protection against UV-B induced erythema. The induction of cellular resistance to UV insults may possibly be explained by the induction of a state a natural resistance to the skin via specific cell signaling pathways and without the drawbacks and limitations of traditional sunscreens. These results represent an encouraging step towards expanding the potential applications of LED therapy and could be useful in the treatment of patients with anomalous reactions to sunlight.

New strategies of photoprotection

Adequate photoprotection is essential to control UV-related disorders, including sunburn, photoaging and photocarcinogenisis. Sun avoidance, protection of skin with clothing, and sunscreens are presently the best way of photoprotection, assuming that they are used properly. However, new strategies, which are based on or make use of the endogenous protective response to UV light, may further improve currently used photoprotective means. The addition of repair enzymes and/or antioxidants has a positive effect on skin's recovery from UV-induced DNA-damage. Several botanical agents, mainly vitamins and polyphenols, have shown to influence signal transduction pathways leading to photoprotective effects. Also stimulation of endogenous UV-response pathways via irradiation with a low UV dose or via simulation of UV-induced DNA-damage results in photoprotective effects. Future research in this field and combination of different photoprotective strategies will hopefully lead to improved photoprotection.