• Toxicological Research
• /
• v.31 no.2
• /
• pp.89-96
• /
• 2015

Atopic dermatitis is a chronic inflammatory skin condition including severe pruritus, xerosis, visible eczematous skin lesions that mainly begin early in life. Atopic dermatitis exerts a profound impact on the quality of life of patients and their families. The estimated lifetime prevalence of atopic dermatitis has increased 2~3 fold during over the past 30 years, especially in urban areas in industrialized countries, emphasizing the importance of life-style and environment in the pathogenesis of atopic diseases. While the interplay of individual genetic predisposition and environmental factors contribute to the development of atopic dermatitis, the recent increase in the prevalence of atopic dermatitis might be attributed to increased exposure to various environmental factors rather than alterations in human genome. In recent decades, there has been an increasing exposure to chemicals from a variety of sources. In this study, the effects of various environmental chemicals we face in everyday life - air pollutants, contact allergens and skin irritants, ingredients in cosmetics and personal care products, and food additives - on the prevalence and severity of atopic dermatitis are reviewed.

• Biomolecules & Therapeutics
• /
• v.23 no.4
• /
• pp.379-385
• /
• 2015

The eye irritation potential of drug candidates or pharmaceutical ingredients should be evaluated if there is a possibility of ocular exposure. Traditionally, the ocular irritation has been evaluated by the rabbit Draize test. However, rabbit eyes are more sensitive to irritants than human eyes, therefore substantial level of false positives are unavoidable. To resolve this species difference, several three-dimensional human corneal epithelial (HCE) models have been developed as alternative eye irritation test methods. Recently, we introduced a new HCE model, MCTT HCE$^{TM}$ which is reconstructed with non-transformed human corneal cells from limbal tissues. Here, we examined if MCTT HCE$^{TM}$ can be employed to evaluate eye irritation potential of solid substances. Through optimization of washing method and exposure time, treatment time was established as 10 min and washing procedure was set up as 4 times of washing with 10 mL of PBS and shaking in 30 mL of PBS in a beaker. With the established eye irritation test protocol, 11 solid substances (5 non-irritants, 6 irritants) were evaluated which demonstrated an excellent predictive capacity (100% accuracy, 100% specificity and 100% sensitivity). We also compared the performance of our test method with rabbit Draize test results and in vitro cytotoxicity test with 2D human corneal epithelial cell lines.

• YAKHAK HOEJI
• /
• v.49 no.2
• /
• pp.174-179
• /
• 2005

The human skin is constantly exposed to environmental irritants such as ultraviolet, smoke, chemicals. Free radicals and reactive oxygen species (ROS) caused by these environmen tal facts play critical roles in cellular damage. These irritants are in themselves damaging to the skin structure but they also participate the immensely complex inflammatory reaction. The purpose of this study was to investigate the skin cell protective effect of Campsis grandiflora extract on the UVB-irradiated human dermal fibroblasts (HDFs). We tested free radical and superoxide scavenging effect in vitro. C. grandiflora extracts had potent radical scavenging effect by 82% at $100{\mu}g/ml$, respectively. For testing intracellular ROS scavenging activity the cultured HDFs were analyzed by increase in DCF fluorescence upon exposure to UVB 20 $MJ/cm^2$ after treatment of C.grandiflora extracts. The results showed that oxidation of CM-DCFDA was inhibited by C.grandiflora extracts effectively and C.grandiflora extracts has a potent free radical scavenging activity in UVB- irradiated HDFs. In ROS imaging using confocal microscope we visualized DCF fluorescence in HDFs directly. In conclusion, our results suggest that C.grandiflora can be effectively used for the prevention of UV-induced adverse skin reactions such as radical production, and skin cell damage.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.26 no.1
• /
• pp.17-40
• /
• 2000

Cytotoxicity assays using artificial skins have been proposed as in vitro alternatives to minimize animal ocular and dermal irritation testing. Accordingly, the responses of artificial skins to the well-characterized chemical irritants toluene, glutaraldehyde, and sodium lauryl sulfate (SLS), and the nonirritant polyethylene glycol were studied. The evaluation of the irritating and non-irritating test chemicals was also compared with the responses observed in human dermal fibroblasts and human epidermal keratinocytes grown in a monolayer culture. The responses monitored included an MTT mitochondrial functionality assay. In order to better understand the local mechanisms involved in skin damage and repair, the production of several mitogenic proinflammatory mediators, interleukin-l$\alpha$, 12-HETE, and 15-HETE, was also investigated. Dose-dependent increases in the levels of かIn and the HETEs were observed in the underlying medium of the skin systems exposed to the two skin irritants, glutaraldehyde and SLS. The results of the present study show that both human artificial skins can be used as efficient in vitro testing models for the evaluation of skin toxicity and for screening contact skin irritancy.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.30 no.1
• /
• pp.23-28
• /
• 2004

The aim of this study is to assess the anti-irritation activities of mung bean (Phaseolus aureus) extract against various irritants used in cosmetics. For its antidotal activity, mung bean has been used as a medicinal or cosmetic material since ancient times. However, there have been few reports describing the biological activities of these beans and no comprehensive surveys of the constituents. We obtained an ethanolic extract of mung bean and isolated the major constituents, such as vitexin and isovitexin. And we previously reported that the mung bean extract containing vitexin and isovitexin had excellent antioxidant and anti-inflammatory activities. To investigate the mechanisms of anti-inflammatory activity of mung bean extract, we examined the inhibitory effects on histamine release from rat peritoneal mast cells and lipoxygenase activity. Mung bean extract inhibited histamine release in a concentration dependent manner but showed no inhibitory activity in the 5-lipoxygenase assay. And, clinical studies were conducted to evaluate the anti-irritation effects of mung bean extract against various irritants used in cosmetics such as lactic acid, retinol, and preservatives. When 2.0％ of mung bean extract was applied to cosmetic formulae containing each of irritants, it revealed considerable anti-irritation efficacy. Our results of the human patch test with 20 volunteers showed that this extract reduced skin irritations caused by 5.0％ lactic acid, 4000 IU retinol, and 1.0％ preservative mixture by about 60％, 30％, and 50％ respectively. The stinging potential test for assessing subjective irritation also showed that the extract reduced the unpleasant sensations by about 50∼30％. Finally, we performed a double-blind usage test with 30 subjects to compare formulae containing mung bean extract with placebo. From the results of questionnaires for 4 weeks of use, we confirmed the excellent anti-irritation effect of mung bean extract. Conclusively, we could discover new material that had anti-irritation effects and apply this mung bean extract to the final cosmetic products successfully.

• Journal of Yeungnam Medical Science
• /
• v.16 no.1
• /
• pp.15-24
• /
• 1999

Although traditionally viewed as a physical barrier between the host and a variety of inhaled irritants and pathogens, it has become clear that the epithelium has a much broader functional scope. Epithelial cells arc metabolically active and can play an important role in the regulation of the allergic inflammatory response. This review provides a consideration of the role of the epithelial cell as both a "target" for exogenous and endogenous stimuli and as an "effector" cell that is capable of producing a variety of products that can influence the inflammatory response in the airways.

• The Journal of the Korean dental association
• /
• v.12 no.8
• /
• pp.619-622
• /
• 1974

The purpose of this study was to investigate biological tissue reactions to various restorative dental materials. An experimental pellects was implanted into subdermal tissue in dog subjects observing 1 week, 3 weeks, and 8 weeks respectively. The obtained histo-pathological findings were as follows: 1. Experimental pellets such as gold, ticonium and amalgam alloy are considered biologically acceptable. 2. Experimental results in 1 week dog showed acute inflammatory changes. 3. Experimental results in 8 week dog showed fibrotic and chronic inflammatory changes. 4. Active irritans such as silicate cements revealed acute inflammatory changes in all observed period. 5. Biological tissue to irritants observed.

• Proceedings of the KACD Conference
• /
• 2001.11a
• /
• pp.571-571
• /
• 2001

The purpose of obturating the prepared root canal can be simply stated as to eliminate all avenues of leakage from the oral cavity or the periradicular tissues into the root canal system and to seal within the system any irritants that cannot be fully removed during canal cleaning and shaping procedures. The ability to achieve three-dimensional obturation of the root canal system is primarily dependent on the quality of the canal cleaning and shaping and the skill of the clinician.(omitted)

• The Journal of the Korean dental association
• /
• v.20 no.1 s.152
• /
• pp.59-62
• /
• 1982

290 cases of diabetics and 290 cases of non-diabetics who came to the department of Internal Medicine and Dental clinic in the National Medical Center were examined with oral examination and intra-oral x-ray study from February, 1977 to January, 1981. The obtained results were as follows; In the diabetics gingival inflammatory changes, alveolar bone resorption and tooth mobility were more severe than non-diabetics who had similar local irritants in the oral cavities.

• International Journal of Oral Biology
• /
• v.37 no.2
• /
• pp.57-62
• /
• 2012

The nasal cavity encounters various irritants during inhalation such as dust and pathogens. To detect and remove these irritants, it has been postulated that the nasal mucosa epithelium has a specialized sensing system. The oral cavity, on the other hand, is known to have bitter taste receptors (T2Rs) that can detect harmful substances to prevent ingestion. Recently, solitary chemosensory cells expressing T2R subtypes have been found in the respiratory epithelium of rodents. In addition, T2Rs have been identified in the human airway epithelia. However, it is not clear which T2Rs are expressed in the human nasal mucosa epithelium and whether they mediate the removal of foreign materials through increased cilia movement. In our current study, we show that human T2R receptors indeed function also in the nasal mucosa epithelium. Our RT-PCR data indicate that the T2R subtypes (T2R3, T2R4, T2R5, T2R10, T2R13, T2R14, T2R39, T2R43, T2R44, T2R 45, T2R46, T2R47, T2R48, T2R49, and T2R50) are expressed in human nasal mucosa. Furthermore, we have found that T2R receptor activators such as bitter chemicals augments the ciliary beating frequency. Our results thus demonstrate that T2Rs are likely to function in the cleanup of inhaled dust and pathogens by increasing ciliary movement. This would suggest that T2Rs are feasible molecular targets for the development of novel treatment strategies for nasal infection and inflammation.