Melanin is produced by melanocytes of the melanoepidermic unit and other cell types. These cells secrete and distribute the melanin pigment, which provides protection from ultraviolet radiation. In this study, the inhibitory activity against tyrosinase and melanin biosynthesis in B16F10 melanoma cells and anti-wrinkling effects on human dermal fibroblasts of Dendrobium speciosum ethanol extract were investigated. The Dendrobium speciosum extract inhibited melanin biosynthesis and tyrosinase activity in a dose-dependent manner in comparison with an untreated control group. Treatment with the Dendrobium speciosum extract suppressed α-MSH-stimulated melanogenesis in B16F10 cells and the dendrite outgrowth of melanocyte/melanoma cells. The α-MSH-induced mRNA expression of tyrosinase-related protein-1 (TRP-1), tyrosinase-related protein-2 (TRP-2) and microphthalmia-associated transcription factor (MITF) was significantly attenuated in a concentration-dependent manner by Dendrobium speciosum treatment. In addition, Dendrobium speciosum treatment increased production of type I procollagen synthesis in human dermal fibroblasts. Dendrobium speciosum ethanol extract exhibited a potent inhibitory effect on melanin biosynthesis, tyrosinase activity and increased procollagen synthesis. These results indicate that Dendrobium speciosum shows promise as an ingredient in cosmeceutical products due to its whitening and anti-wrinkle effects.

Background : Irregular meals and insufficient exercise are major modern lifestyle-related risk factors for constipation. This study aimed to examine the effects of the aqueous extract of Dendrobium speciosum var. (DM) on the improvement of intestinal function and prevention of constipation in rats. Methods and Results : Constipation in rat was induced by loperamide (4 ㎎/㎏) injection for 5 days and rats were randomly assigned to the following groups: normal control rats (NOR), constipated rats (LOP induced) and constipated rats supplemented with dulcolax-S (POS), DMSG, 100 ㎎/㎏ (DMSG-100), 300 ㎎/㎏ (DMSG-300) and 500 ㎎/㎏ (DMSG-500). The DMSG groups showed increments in the frequency and amount of stools compared to the LOP group. Loperamide treatment markedly reduced the water content of feces, whereas DMSG administration significantly increased fecal water contents. Moreover, DMSG improved intestinal transit speed in constipated-rats. Alcian blue staining revealed increased mucus production by crypt cells and mucus contents in feces and the mucosal surface. Conclusions : In summary, DM extraction significantly improves intestinal function in rats, which indicates the effectiveness of this extract in the prevention and treatment of constipation.