The Accumulation of Crocin and Geniposide and Transcripts of Phytoene Synthase during Maturation ofGardenia jasminoidesFruit

Lan Gao,Bi-Yun Zhu

doi:10.1155/2013/686351

Abstract

Gardenia fruit (fruit of Gardenia jasminoides Ellis) is used as a natural pigment resource and a Chinese traditional medicine. The white mesocarp turning orange or red that occurs during gardenia fruit maturation arises from the production and accumulation of the apocarotenoids, especially crocin-1, which is derived from carotenoid. Meanwhile, the major medical component geniposide is accumulated in gardenia fruit. To further our understanding of the synthetic and accumulation mechanism for crocin-1 and geniposide in gardenia fruit, the contents of crocin-1 and geniposide and the transcripts of phytoene synthase (GjPSY) profiles in gardenia fruits were examined at various stages of maturation. The concentration of crocin-1 and geniposide in gardenia fruit was determined by reversed-phase high-performance liquid chromatography (HPLC). The results showed that the concentration of crocetin-1 was increased during fruit development and the concentration of geniposide does not change significantly during maturing. The expression levels of GjPSY mRNA were examined by RT-PCR. It was revealed that GjPSY was constitutively expressed during fruit development, suggesting that the primary mechanism that controls crocin accumulation in G. jasminoides fruits during development is not correlated to the differential regulation of transcript levels of GjPSY gene.

Highlights

Gardenia fruits are widely used in Asian countries as a natural colorant and as a Chinese traditional herbal medicine since they have homeostatic, hepatoprotective, analgesic, antiphlogistic, antipyretic, and hypolipidaemic effect [1]
In animal and human studies, it has been shown that crocin and crocetin exhibit a variety of pharmacological effects, such as antioxidant [10], antihyperlipidemia [11], antiatherosclerotic [12], antiinflammatory [13], antiproliferation [14], neuroprotective effects [15], insulin resistance improvement [16], positive effects on sleep [17], and attenuation of physical fatigue [18], and prevent retinal degeneration [19]
Though it is known that gardenia fruits naturally accumulate crocin, crocetin, and geniposide, the biochemical pathway leading to these compounds in G. jasminoides is not clear; from previous work, we isolated the cDNA coding for phytoene synthase from the gardenia fruit

Summary

Introduction

Gardenia fruits are widely used in Asian countries as a natural colorant and as a Chinese traditional herbal medicine since they have homeostatic, hepatoprotective, analgesic, antiphlogistic, antipyretic, and hypolipidaemic effect [1]. Geniposide is a predominant iridoid compound present in gardenia fruits (Figure 1), exhibit a wide range of pharmacological activities, was reported to have hepatoprotective effect [3], hypoglycemic effect [4], insulin resistancealleviating effect [5], antiproliferation effect [6], antioxidant effect [7], and antioxidant and neuroprotective effect [8], and is a cross-linker to make polymeric material in biomedical applications [9]. Though it is known that gardenia fruits naturally accumulate crocin, crocetin, and geniposide, the biochemical pathway leading to these compounds in G. jasminoides is not clear; from previous work, we isolated the cDNA coding for phytoene synthase from the gardenia fruit In order to gain insight into the molecular basis of crocin and geniposide synthesis, obtain data concerning major chemicals crocin and geniposide concentration for the determination of optimal time of harvest, and to determine when and if GjPSY transcript levels in the developing fruit correlate with apocarotenoid accumulation, the contents of crocin and geniposide and the transcriptional expression of GjPSY in the fruits at various development stages were analyzed

Materials and Methods

Results and Discussion

Conclusion