Artocarpus altilis heartwood extract protects skin against UVB in vitro and in vivo

Ethnopharmacological relevance: Artocarpus altilis (Moreceae) has been widely used as a traditional folk medicine in Southeast Asia for the treatment of many diseases, including skin disorders, such as ulcers and dermatitis. Aim of the study: The present study aimed to investigate the ability of an artocarpin-enriched extract to prevent ultraviolet radiation B-induced photodamage. Materials and methods: The content of artocarpin in the extract was determined by high performance liquid chromatography (HPLC). A DPPH assay was used to evaluate the free radical scavenging activity of the extract, which was compared with those of I.-ascorbic acid and a-tocopherol. Cytotoxicity and proliferation of cells treated with the extract were determined using XTF and BrdU assays, respectively. Human skin fibroblasts and keratinocytes were pretreated with the extract for 24 h and later irradiated with ultraviolet radiation B at 128 J/cm(2). The levels of TNF-alpha and IL-6 released from ultraviolet radiation B-irradiated keratinocytes and, MMP-1 and type-I procollagen produced by ultraviolet radiation B-irradiated fibroblasts were measured by ELISA and/or western blotting. The hairless skin of male mice (outbred ICR) was treated with the extract or L-ascorbic acid solution prior to exposure to ultraviolet radiation B irradiation. The dose of ultraviolet B irradiation was consecutively increased to 18, 36, 54, and 72 J/cm(2) at weeks 1-4, 4-7, 7-10, and 10-12, respectively. The epidermal thickness and collagen content in the skin of ultraviolet radiation B-irradiated mice were evaluated. Results: The extract concentration of 50 mu g/mL was not toxic and did not inhibit the proliferation of fibroblasts. The pretreatment of fibroblasts with 50 mu g/mL extract prior to ultraviolet radiation B irradiation attenuated MMP-1 production but did not affect type-I procollagen production. The extract also decreased the ultraviolet radiation B-induced production of TNF-alpha and IL-6 in keratinocytes. Moreover, the topical administration of the extract suppressed epidermal thickening and collagen loss in chronically ultraviolet radiation B-exposed skin in mice. Conclusions: The experimental study revealed that A. altilis extract suppresses structural alterations in skin damaged by ultraviolet radiation B irradiation. This suppression was, at least partially, mediated by decrease in MMP-1 production in fibroblasts and TNF-alpha and IL-6 productions in keratinocytes. (C) 2015 Elsevier Ireland Ltd. All rights reserved.