Bioshell calcium oxide (BiSCaO) for cleansing and healing Pseudomonas aeruginosa-infected wounds in hairless rats.

BACKGROUND: Scallop shell powder is called bioshell calcium oxide (BiSCaO), which is known to possess deodorizing properties and broad antimicrobial activity against various pathogenic microbes, including viruses, bacteria, spores, and fungi. OBJECTIVE: This study aims to investigate the applications of BiSCaO suspension cleansing in clinical situations, for instance for the prevention and treatment of infections in chronic wounds in healing-impaired patients, without delaying wound healing. METHODS: The bactericidal activities of 1000 ppm BiSCaO suspension; 500 ppm hypochlorous acid; 1000 ppm povidone iodine; and saline were compared to evaluate in vivo disinfection and healing of Pseudomonas aeruginosa-infected wounds in hairless rats. RESULTS: Cleansing of the infected wounds with BiSCaO suspension daily for 3 days significantly enhanced wound healing and reduced the in vivo bacterial counts, in comparison to hypochlorous acid, povidone iodine, and saline. Furthermore, histological examinations showed significantly advanced granulation tissue and capillary formation in the wounds cleansed with BiSCaO suspension than in those cleansed with the other solutions. CONCLUSIONS: This study suggested that the possibility of using BiSCaO suspension as a disinfectant for infected wounds and limiting disinfection to 3 days may be sufficient to avoid the negative effects on wound repair.

Effects of cocoa-enriched diet on orofacial pain in a murine model.

OBJECTIVES: To investigate and discuss the effects of cocoa on orofacial pain. SETTING AND SAMPLE POPULATION: The Department of Orthodontics at the University of Florida (UF). Male and female hairless rats (N=20/group) were tested. MATERIALS AND METHODS: Rats were tested using the Orofacial Pain Assessment Device (OPAD) before and after changing their food from the standard chow to a cocoa-enriched or control-equivalent diet. RESULTS: Male rats fed the cocoa diet had a significantly higher operant pain index when tested at 37°C as compared to control diet-fed animals. Female rats on the cocoa diet had a significantly higher pain index when tested at 18°C and 44°C, as compared to animals fed the control diet. Capsaicin-induced pain was inhibited, with cocoa-diet male rats having a significantly higher pain index than control-diet male rats and cocoa-diet female rats at both 37°C and 44°C. Cocoa-diet female rats had a significantly higher pain index at 44°C than control-diet females. Mechanical sensitivity was affected following capsaicin cream, with a significantly decreased tolerated bottle distance in both cocoa- and control-diet animals, but there was no difference between cocoa- and control-diet groups. CONCLUSION: Using the OPAD operant system, we demonstrated that a diet rich in cocoa was effective in inhibiting neurogenic inflammatory pain in rats. This has implications for the use of novel alternative therapies such as diet modification for pain control.

Topical Delivery of Fenoprofen Calcium via Elastic Nano-vesicular Spanlastics: Optimization Using Experimental Design and In Vivo Evaluation.

The aim of this study was to investigate the potential of surfactant-based nanovesicular system (spanlastics) for topical delivery of fenoprofen calcium (FPCa) to eliminate its oral gastrointestinal adverse effects. FPCa-loaded spanlastics were prepared by thin film hydration (TFH) technique according to a full factorial design to investigate the influence of formulation variables on the drug entrapment efficiency (%EE), particle size (PS), deformability index (DI), and the % drug released after 24 h through the cellulose membrane (Q24h) using Design-Expert® software. The optimized formula (composed of Span 60 and Tween 60 as an edge activator at weight ratio of 8: 2 in presence of Transcutol P as a cosolvent in the hydration media) exhibited the highest %EE (49.91 ± 2.60%), PS of 536.1 ± 17.14 nm, DI of 5.07 ± 0.06 g, and Q24h of 61.11 ± 2.70%; it was also characterized for morphology and physical stability. In vitro release study of FPCa-loaded spanlastic gel and conventional FPCa gel through a synthetic membrane and hairless rat skin were evaluated. The skin permeation study revealed that spanlastic gel exhibited both consistent and prolonged action. Finally, the % inhibition of carrageenan-induced rat paw edema of spanlastic gel was three times higher than the conventional FPCa gel after 24 h. In conclusion, spanlastic-based gel could be a great approach for improving topical delivery of fenoprofen calcium, providing both prolonged and enhanced anti-inflammatory activity in the treatment of arthritis.

Melatonin pharmacokinetics after transdermal administration changes according to the time of the day.

Melatonin is a neurohormone with multiple and different actions, such as chronobiotic or antioxidant. Melatonin is usually orally administered, but dermal administration is also useful in dermatological diseases or as adjuvant to certain skin treatments. Here, we studied the variability of the pharmacokinetics of melatonin and its metabolite AFMK, when melatonin is transdermally administered to Hairless rat at two different times of day (Zeitgeber Time 4 (ZT4) and ZT16). Moreover, in order to obtain the bioavailability, kinetics after intravenous administration was also studied. In addition, a permeation study was carried out, at both ZTs, to test the amount of melatonin retained in the skin after transdermal administration. Results showed that pharmacokinetic parameters of melatonin administered exogenously depended on the time of the day. When intravenous data were fitted to a compartmental model, the extrapolated plasma concentration at time 0 and the area under the curve were higher at ZT4, while clearance, volumes of central and peripheral compartments and volume of distribution at the steady state were higher at ZT16. Transdermal administration was best fitted to a one-compartment model and tmax, half-life of absorption and area under the curve showed higher values at ZT4, while the absorption rate and constant of absorption were higher at ZT16. AFMK was detected in all cases, but no differences between the two ZTs were observed. Transdermal administration showed better bioavailability also at ZT4. Results indicate that time of day is a variable that should be taken into account when melatonin is transdermally administered.

Transdermal Delivery of Iron Using Soluble Microneedles: Dermal Kinetics and Safety.

Currently, the iron compounds are administered via oral and parenteral routes in patients of all ages, to treat iron deficiency. Despite continued efforts to supplement iron via these conventional routes, iron deficiency still remains the most prevalent nutritional disorder all over the world. Transdermal replenishment of iron is a novel, potential approach of iron replenishment. Ferric pyrophosphate (FPP) was found to be a suitable source of iron for transdermal replenishment. The safety of FPP was assessed in this project by challenging the dermal fibroblast cells with high concentration of FPP. The cell viability assay and reactive oxygen species assay were performed. The soluble microneedle array was developed, incorporated with FPP and the kinetics of free iron in the skin; extracellular fluid following dermal administration of microneedle array was investigated in hairless rats. From the cell based assays, FPP was selected as one of the potential iron sources for transdermal delivery. The microneedles were found to dissolve in the skin fluid within 3 hours of administration. The FPP concentration in the dermal extracellular fluid declined after complete dissolution of the microneedle array. Overall, the studies demonstrated the safety of FPP for dermal delivery and the feasibility of soluble microneedle approach for transdermal iron replenishment therapy.

Micronucleated erythrocytes in newborns of rat dams exposed to ultraviolet-A light during pregnancy; protection by ascorbic acid supplementation.

Pregnant hairless rat dams were exposed to ultraviolet-A light (UVA) to induce micronucleated erythrocytes (MNE) in their fetuses. The control group was exposed to conventional light; the experimental groups were exposed to UVA (365nm) during gestational days 16-21. In some cases, ascorbic acid (Asc) was administered in the drinking water from gestational day 15 until delivery. Dams were sampled at 48-h intervals during gestation, from day 16 until delivery. Blood was also obtained from neonates at birth; MNE, micronucleated polychromatic erythrocytes (MNPCE), and polychromatic erythrocytes (PCE) were scored. Increased MNE and MNPCE were observed in neonates born to mothers exposed to UVA for 40, 80 or 160min, compared to the control group. Asc treatment reduced MNE and MNPCE induction.

In vivo enhancement of transdermal absorption of ketotifen by supersaturation generated by amorphous form of the drug.

The enhancing effect of supersaturation generated by amorphous ketotifen in silicone pressure-sensitive adhesive matrices (PSA) on the transdermal absorption was evaluated in vivo using hairless rats, and it was compared with the increase of drug amount in skin tissues. The duration of the enhancing effect was also investigated in relation to the time how long supersaturation was maintained in PSA. PSA containing crystalline ketotifen (PSA-Crystalline) and that containing amorphous ketotifen (PSA-Amorphous) were prepared by the solvent casting method using n-hexane and dichloromethane, respectively. In vivo transdermal absorption was evaluated by measuring the amount of ketotifen in PSAs, the stratum corneum, and viable skin tissues after administration of PSAs on abdominal sites of hairless rats. The amount of ketotifen absorbed into the systemic circulation was calculated by subtracting the drug amount in whole skin tissues from the amount of the drug released from PSAs, then it was monitored for up to 23 h. In both types of PSA, a constant absorption rate was maintained for up to 23 h after 7-h lag time. The enhancement factor of PSA-Amorphous against PSA-Crystalline was approximately 7, which was in good agreement with the difference of drug amount in viable skin tissues. Time course of the drug amount in PSA-Amorphous suggested that the supersaturated level was gradually decreased after 10h, but the decline of the driving force from PSAs was supplemented by the drug release from the skin depot resulting in the constant absorption rate up to 23 h. These results suggest the usefulness of amorphous ketotifen to obtain enhanced transdermal absorption.

The systemic effect of 830-nm LED phototherapy on the wound healing of burn injuries: A controlled study in mouse and rat models.

BACKGROUND: The present controlled study assessed the systemic effect of 830-nm LED phototherapy in rodent models. MATERIALS AND METHODS: Two HR-1 hairless mice and 3 HWY/Slc hairless rats were divided into two groups: the treatment group (Tx Group, one mouse, two rats) and the control group (Con Group, one mouse, one rat). All animals received an identical 12 mm × 12 mm control burn over three sites on the dorsum with a fractional ablative CO(2) laser. Wounds were protected with a film-type dressing. The abdomen of the Tx Group subjects was irradiated with an 830-nm LED array immediately post CO(2) treatment and then at 1, 5 and 6 days post laser irradiation. Wound healing was assessed macroscopically from the clinical photography. RESULTS: At the 2-day post-laser assessment, the healing process in the wounds in the Tx Group was already apparent compared with the Con Group. At the final evaluation (post-burn day 7), no site on the Con Group (six wounds) showed 100% healing, recovery was over 70% in four and lower than 50% in two sites. Of the nine Tx Group sites, 100% recovery was seen in three sites, over 70% in five sites and one wound was exacerbated through trauma. CONCLUSIONS: LED phototherapy on the abdomen produced faster wound healing of the uniform burn wounds than in animals with the same burn wounds that did not receive LED phototherapy, strongly suggesting the systemic effect of phototherapy.

Pretreatment effects of moxibustion on the skin permeation and skin and muscle concentrations of salicylate in rats.

The effect of moxibustion on the in vitro and in vivo skin permeation of salicylate was evaluated in rats. First, the effect of moxibustion pretreatment on the elimination pharmacokinetics of salicylate after i.v. injection in rats was determined: no clear difference was observed in the plasma profiles of salicylate (SA) with or without moxibustion pretreatment. However, much higher skin and muscle concentrations of salicylate were observed after its i.v. injection. Next, an in vitro skin permeation study of SA was performed after moxibustion pretreatment. Moxibustion pretreatment increased the skin permeation of SA, and the extent of the increase in SA skin permeation was related to the strength of moxibustion ignition. More intense treatments produced higher skin permeation. A similar enhancement effect on the skin permeation of SA was observed in in vivo studies. Interestingly, the skin/plasma and muscle/plasma ratios of SA were markedly increased by moxibustion pretreatment. These results were due to the induction of enhanced skin permeation and lower clearance into the cutaneous vessels by moxibustion ignition. Combination treatment involving moxibustion and the topical application of drugs such as NSAID may be useful for increasing local pharmaceutical effects by enhancing the drug concentration in the skin and muscle underneath the topical application site.

Preparation and evaluation of liquid-crystal formulations with skin-permeation-enhancing abilities for entrapped drugs.

The usefulness of liquid crystals (LC) in topical formulations for application to skin was evaluated by measuring the in vitro permeation profile of a model compound, calcein, entrapped in a LC formulation, through excised hairless rat skin and a three-dimensional cultured human-skin model; the viability was determined using the MTT assay. Two physically stable LCs were prepared from a mixture of mono-, di-, and tri-esters 1, and monoesters 2, composed of erythritol and phytanylacetic acid. Cryo-transmission electron microscopy (cryo-TEM), electron diffraction patterns, and small-angle X-ray diffraction (SAXS) observations of the LC nanodispersions showed that the structures of the LCs were reverse hexagonal (LC-A) and cubic (LC-B). The skin-permeation properties of calcein were enhanced by entrapping in the LCs as a result of the increase in calcein partition from the LC dispersion solution into the skin; the properties were analyzed using a skin-permeation-time profile. Drug partitioning could also be modified by the LC structure. No skin damage was caused by the LC formulation in these experiments.The present study suggests that LC dispersions are potential additives in topical drug formulations and cosmetic formulations.

A combination of curcumin and ginger extract improves abrasion wound healing in corticosteroid-impaired hairless rat skin.

Hairless rats were topically treated with a combination of 10% curcumin and 3% ginger extract (or with each agent alone) for a 21-day period. Following this, the rats were treated topically with Temovate (corticosteroid) for an additional 15 days. At the end of the treatment period, superficial abrasion wounds were induced in the treated skin. Abrasion wounds healed more slowly in the skin of Temovate-treated rats than in skin of control animals. Healing was more rapid in skin of rats that had been pretreated with either curcumin or ginger extract alone or with the combination of curcumin-ginger extract (along with Temovate) than in the skin of rats treated with Temovate and vehicle alone. Skin samples were obtained at the time of wound closure. Collagen production was increased and matrix metalloproteinase-9 production was decreased in the recently healed skin from rats treated with the botanical preparation relative to rats treated with Temovate plus vehicle. In none of the rats was there any indication of skin irritation during the treatment phase or during wounding and repair. Taken together, these data suggest that a combination of curcumin and ginger extract might provide a novel approach to improving structure and function in skin and, concomitantly, reducing formation of nonhealing wounds in "at-risk" skin.

Effects of oral epigallocatechin gallate supplementation on the minimal erythema dose and UV-induced skin damage.

BACKGROUND/AIMS: Excessive exposure to UV radiation causes acute adverse effects like sunburn and photosensitivity reactions and is involved in the induction and development of skin cancer. It has been reported that antioxidants have photoprotective effects against solar UV radiation. We investigated the effect of oral epigallocatechin gallate (EGCG), a powerful antioxidant in green tea, on the minimal erythema dose (MED) and UV-induced skin damage. METHOD: Female HWY/Slc hairless rats were fed the normal diet supplemented with 1,500 ppm EGCG for 8 weeks; then, the MED was determined and visual scores and transepidermal water loss were assessed to evaluate the severity of UV-induced skin damage. RESULTS: At week 8 of the study, the use of dietary EGCG significantly increased MED. UV-radiation-induced sunburn severity and alterations in epidermal barrier function were also attenuated by the supplementation of EGCG. CONCLUSION: Regular intake of EGCG strengthens the skin's tolerance by increasing MED and thus prevents UV-induced perturbation of epidermal barrier function and skin damage. These results suggest that EGCG is a potent candidate for systemic photoprotection.

Blockade of atopic dermatitis-like skin lesions by DA-9102, a natural medicine isolated from Actinidia arguta, in the Mg-deficiency induced dermatitis model of hairless rats.

DA-9102 isolated from Actinidia arguta is a candidate of natural medicine currently under Phase II clinical trial for atopic dermatitis in Korea. In this study, spontaneous dermatitis was induced by magnesium deficiency in hairless rats and this system was applied to assess the suppressive effects of DA-9102 on atopic dermatitis-like skin disease. Oral administration of DA-9102 at a dose of 100 mg/kg for 16 days substantially suppressed the occurrence of spontaneous dermatitis. Eczematous skin lesions, water loss and scratching behavior were significantly decreased by DA-9102 in a dose-dependent manner. Infiltration of inflammatory cells into the skin and pathologic remodeling of the epidermis and dermis were much less than the Mg-def. group. Results from flow cytometry analysis of peripheral blood mononuclear cells indicated that DA-9102 suppressed activation of leukocytes. The decrease in the number of CD45RA+ cells was accompanied by a lower level of IgE in DA-9102 treated rats, and the reduction in the number of CD11b+ cells by DA-9102 in both periphery and skin was significant. Further, DA-9102 not only suppressed the mRNA expression of T(H)2 cytokines including IL-4 and IL-10 in the lymph node but it also decreased the levels of inflammatory mediators such as nitric oxide and leukotriene B(4) (LTB(4)) in the serum. Taken together, these results suggest that DA-9102 is an orally applicable potent immune modulator capable of controlling the occurrence of atopic dermatitis-like skin disease.

Polypodium leucotomos extract inhibits glutathione oxidation and prevents Langerhans cell depletion induced by UVB/UVA radiation in a hairless rat model.

In this report, we have addressed the effect of oral administration of a hydrophilic extract of the fern Polypodium leucotomos (PL) on the deleterious effects of ultraviolet radiation (UVR) on the levels of epidermal and plasmatic antioxidants in hairless rats. We have found that pretreatment with PL effectively reduced glutathione oxidation in both blood and epidermis, suggesting a potent systemic antioxidant effect. In addition, PL inhibited UVR-mediated Langerhans cell (LC) depletion. Our results demonstrate the efficacy of PL as an oral antioxidant and photoimmunoprotective agent and support its employment as a complement to topical sunscreens.

Percutaneous penetration of uranium in rats after a contamination on intact or wounded skin.

The aim of this work is to assess in vivo in a hairless rat model, the percutaneous diffusion of uranium through intact or wounded rat skin. Six types of wounds were simulated by excoriation and burns with 10 N HF, 2, 5 and 14 N HNO3 and 10 N NaOH on anaesthetised hairless rats. Percutaneous penetration through wounded skin towards blood and subsequent urinary excretion of uranium was followed in vivo during 24 h. The influence of the physicochemical form (solution or powder) of uranyl nitrate (UN) on its percutaneous diffusion was also investigated. UN, even as a powder, can diffuse through intact skin. The presence of uranium in blood is more persistent and its urinary elimination is slower after an HF burn than after an HNO3 burn. Excoriation increases dramatically percutaneous absorption of UN. Thus, percutaneous diffusion of UN is largely dependent on skin barrier integrity with a particular importance of stratum corneum.