Efficacy and local irritation evaluation of Eriobotrya japonica leaf ethanol extract.

BACKGROUND: Although Eriobotrya japonica leaves have been studied as a raw material for various cosmetic products, little is known about the anti-oxidant, anti-inflammatory, and anti-melanogenic activities of Eriobotrya japonica leaf ethanol extract (EJEE). METHODS: This study was conducted to evaluate the anti-oxidant, anti-inflammatory, and anti-melanogenic activities of EJEE using different in vitro models. In addition, we investigated the potential irritation of EJEE to skin and eye using animal alternative tests. RESULTS: The total content of polyphenols, one of the active constituents of EJEE, was analyzed by high-performance liquid chromatography and found to contain 88.68 mg tannic acid equivalent/g. EJEE showed a concentration-dependent 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radical scavenging activity, and a superoxide dismutase-like activity. The anti-inflammatory effect of 0.5% (w/v) EJEE was demonstrated by a reduction in lipopolysaccharide-induced nitric oxide and tumor necrosis factor-alpha levels in RAW 264.7 cells. EJEE also significantly inhibited melanogenesis in melanocyte stimulating hormone-induced B16F1 cells. EJEE did not show any irritation in skin and eye in animal alternative test. CONCLUSIONS: These results indicate that the EJEE possesses anti-oxidant, anti-inflammatory, and anti-melanogenic activities, while it did not induce toxicity or irritation in neither skin nor eye. Therefore, EJEE can be used as a cosmetic ingredient for skin improvement.

Phototoxicity: Its Mechanism and Animal Alternative Test Methods.

The skin exposure to solar irradiation and photoreactive xenobiotics may produce abnormal skin reaction, phototoxicity. Phototoxicity is an acute light-induced response, which occurs when photoreacive chemicals are activated by solar lights and transformed into products cytotoxic against the skin cells. Multifarious symptoms of phototoxicity are identified, skin irritation, erythema, pruritis, and edema that are similar to those of the exaggerated sunburn. Diverse organic chemicals, especially drugs, are known to induce phototoxicity, which is probably from the common possession of UV-absorbing benzene or heterocyclic rings in their molecular structures. Both UVB (290~320 nm) and UVA (320~400 nm) are responsible for the manifestation of phototoxicity. Absorption of photons and absorbed energy (hv) by photoactive chemicals results in molecular changes or generates reactive oxygen species and depending on the way how endogenous molecules are affected by phototoxicants, mechanisms of phototoxcity is categorized into two modes of action: Direct when unstable species from excited state directly react with the endogenous molecules, and indirect when endogeneous molecules react with secondary photoproducts. In order to identify phototoxic potential of a chemical, various test methods have been introduced. Focus is given to animal alternative test methods, i.e., in vitro, and in chemico assays as well as in vivo. 3T3 neutral red uptake assay, erythrocyte photohemolysis test, and phototoxicity test using human 3-dimensional (3D) epidermis model are examples of in vitro assays. In chemico methods evaluate the generation of reactive oxygen species or DNA strand break activity employing plasmid for chemicals, or drugs with phototoxic potential.