Difference of Curcumin Content in Curcuma longa L. (Zingiberaceae) Caused by Hybridization with Other Curcuma Species

Hiroshi Hayakawa,Katsura Ito,Yoshinori Yamamoto,Tatsuya Fukuda,Yukio Minaniya

doi:10.4236/ajps.2011.22013

Abstract

Curcumin, which is traditionally known to have effects on various types of diseases in humans, is found in Curcuma longa L. Previous reports have indicated that the curcumin content varies between the different lines of this species. To clarify the differences in the amounts of curcumin between the lines, we investigated the outcomes of cultivation ex-periments with the hybridization or introgression between C. longa and other Curcuma species using the matK gene of chloroplast DNA (cpDNA) and the external transcribed spacer (ETS) of nuclear DNA (nrDNA). The results show that there is heterogeneity of the ETS and incongruence between the matK and the ETS phylogenetic trees, suggesting that hybridization and introgression had taken place in the diversification of the various lines of C. longa. Moreover, al-though all of the lines had the same cpDNA haplotype of C. longa, the lines of homogeneous C. longa had a high con-tent of curcumin, whereas the lines created by hybridization and introgression with other Curcuma species had a me-dium or low level. These results suggest that the difference of curcumin content among the various lines of C. longa was caused by hybridization and introgression with other Curcuma species.

Highlights

Many chemicals in plants are potential drugs for humans and natural products from plants are found in many therapeutic formulations
To clarify the differences in the amounts of curcumin between the lines, we investigated the outcomes of cultivation experiments with the hybridization or introgression between C. longa and other Curcuma species using the maturase K (matK) gene of chloroplast DNA and the external transcribed spacer (ETS) of nuclear DNA
Our results indicated that hybrid and introgressive individuals with other Curcuma species were included in C. longa hybrid and introgressive have same haplotype of C. longa based on matK sequences of chloroplast DNA (cpDNA) (Figure 1)

Summary

Introduction

Many chemicals in plants are potential drugs for humans and natural products from plants are found in many therapeutic formulations. Curcuma longa L., which belongs to the ginger family, Zingiberaceae, is a perennial widely used as a spice, a colorant and as a major ingredient of curry powder [2]. This species has a long history of use as a traditional medicine in China and India [3], reflecting it’s diverse and beneficial health effects. Curcumin is well-known to have therapeutic effects on a variety of human diseases, and the cancer preventive activity of curcumin is being intensively studied all over the world. Curcumin inhibits the cell growth of various cancer cell lines, induces apoptosis of cancer cells [5,6,7], and was effective on the cell-cycle regulation of cancer cells [8]

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Conclusion