A New Marker for Evaluation of Royal Jelly
Department of Surgery, Asahikawa Medical College1), Japan Royal Jelly Co., Ltd2), Laboratory Science, Faculty of Health Sciences, Hokkaido University3)
We focused attention on rapid growth of bee larvae (BL) in royal cells promoted by royal jelly (RJ). The substance which promotes the growth of BL has not been clarified, however high quality RJ should abundantly contain this growth-promoting substance. Firstly, we performed fundamental study to disclose the content ratio of soluble proteins in RJ samples using HPLC. Soluble RJ proteins were universally separated into five peaks. Among these peaks, the peaks of 280 kDa and 72 kDa were major and others were minor components. These proteins were extracted and identified by 2-dimensional electrophoresis and MALDI TOF/TOF MS, respectively. The main 280 kDa and 72 kDa peaks on HPLC were Major RJ Protein 1 (MRJP1) and MRJP2, respectively. It has been reported that MRJP1 shows maintenance of cell activities and cell growth activity in vitro. Consequently, MRJP1 is the first candidate of the growth-promoting substance. To test this hypothesis, we performed an experimental apiculture. RJ was collected sequentially (every 4 hours from 24 to 72 hours after the transferring BL) from artificial royal cells and the total amount of protein (TP), trans-10-hydroxy-2-decenoic acid (DA) and MRJP1 were determined. TP and MRJP1 decreased with growth of BL but DA did not show any significant changes. The promotion effect of MRJP1 on the growth of BL was examined in vivo. BL were treated with RJ containing various concentrations of MRJP1. BL growth was promoted by MRJP1 treatment in a dose-dependent manner. From these results, it is strongly demonstrated that MRJP1 is a key protein of BL growth. The amounts of MRJP1 in commercially available RJ samples were determined using HPLC. The amount of MRJP1 was remarkably varied ranged from 30 mAU to 2000 mAU, peak value of HPLC among RJ samples. The study is of novel significance as it demonstrates for the first time that MRJP1 is a key in the growth of BL, and we strongly propose use of MRJP1 to evaluate the quality of RJ.
Key words: royal jelly, major royal jelly protein 1, bee larvae, protein, quality, decenoic acid