With the goal of developing an accurate plant identification method, molecular analysis based on polymorphisms of the nucleotide sequence of chloroplast DNA (cpDNA) was performed in order to distinguish four Curcuma species: C. longa, C. aromatica, C. zedoaria, and C. xanthorrhiza. Nineteen regions of cpDNA were amplified successfully via polymerase chain reaction (PCR) using total DNA of all Curcuma plants. Using the intergenic spacer between trnS and trnfM (trnSfM), all four Curcuma plant species were correctly identified. In addition, the number of AT repeats in the trnSfM region was predictive of the curcumin content in the rhizome of C. longa.

Wasabi has been used as an important spice in Japanese foods. The wasabi leaves were used as a cosmetic material, but its biological activities have not yet been examined. We investigated the effect of isosaponarin derived from wasabi leaf on collagen synthesis in human fibroblasts. The production of type I collagen in human fibroblasts was increased with treatment of wasabi leaf extract. Isosaponarin isolated from wasabi leaves belonged to the group of flavone glycoside, and was the key compound in collagen synthesis from the wasabi leaf ingredients. Isosaponarin increased the type I collagen production at the mRNA gene level. The treatment of isosaponarin did not influence the production of transforming growth factor-beta (TGF-beta) protein, but increased the production of TGF-beta type II receptor (TbetaR-II) protein and TbetaR-II mRNA. Prolyl 4-hydroxylase (P4H) protein and P4H mRNA were increased by treatment with isosaponarin. Heat shock protein 47 (HSP47) was not increased by treatment with isosaponarin. These results suggested that isosaponarin increased collagen synthesis in human fibroblasts, caused by up-regulated TbetaR-II and P4H production.