Identification of a Novel Hypocholesterolemic Protein, Major Royal Jelly Protein 1, Derived from Royal Jelly

Abstract

Royal jelly (RJ) intake lowers serum cholesterol levels in animals and humans, but the active component in RJ that lowers serum cholesterol level and its molecular mechanism are unclear. In this study, we set out to identify the bile acid-binding protein contained in RJ, because dietary bile acid-binding proteins including soybean protein and its peptide are effective in ameliorating hypercholesterolemia. Using a cholic acid-conjugated column, we separated some bile acid-binding proteins from RJ and identified the major RJ protein 1 (MRJP1), MRJP2, and MRJP3 as novel bile acid-binding proteins from RJ, based on matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Purified MRJP1, which is the most abundant protein of the bile acid-binding proteins in RJ, exhibited taurocholate-binding activity in vitro. The micellar solubility of cholesterol was significantly decreased in the presence of MRJP1 compared with casein in vitro. Liver bile acids levels were significantly increased, and cholesterol 7α-hydroxylase (CYP7A1) mRNA and protein tended to increase by MRJP1 feeding compared with the control. CYP7A1 mRNA and protein levels were significantly increased by MRJP1 tryptic hydrolysate treatment compared with that of casein tryptic hydrolysate in hepatocytes. MRJP1 hypocholesterolemic effect has been investigated in rats. The cholesterol-lowering action induced by MRJP1 occurs because MRJP1 interacts with bile acids induces a significant increase in fecal bile acids excretion and a tendency to increase in fecal cholesterol excretion and also enhances the hepatic cholesterol catabolism. We have identified, for the first time, a novel hypocholesterolemic protein, MRJP1, in RJ. Interestingly, MRJP1 exhibits greater hypocholesterolemic activity than the medicine β-sitosterol in rats.

The effect of royal jelly on the growth of breast cancer in mice

“…RJ exhibits a wide variety of functional properties, and has been widely used in cosmetics, healthy foods and commercial medical products in numerous countries. Additionally, RJ possesses various properties, including antimicrobial (2), anti-inflammatory (3,4), hepatoprotective (5), antisarcopenia (6), insulin-like action (7) and antihypercholesterolemic (8) properties. In the recent decades, there have been an increasing number of studies investigating the effects of RJ.…”

Comparative Study on Quality Parameters of Royal Jelly, Apilarnil and Queen Bee Larvae Triturate

“…Commercial RJ is obtained by harvesting the brood food from the queen cell in the 3rd day of larval development (ISO 12824:2016). (Fujii et al, 1990;Kohno et al, 2004), immunoregulatory (Okamoto et al, 2003;Vucevic et al, 2007), insulin-like (Dixit and Patel, 1964;Kramer et al, 1982), estrogen signaling mediating (Moutsatsou et al, 2010), antiaging (Inoue et al, 2003), reducing cholesterol levels (Kashima et al, 2014), vasodilation (Tokunaga et al, 2004).…”

Quality Parameters for Commercial Royal Jelly

“…Royal Jelly is a hive product rich in bioactive compounds with various biological properties and effects: antioxidative (Guo et al, 2005(Guo et al, , 2009Jamnik et al, 2007;Silici et al, 2009; DelkhosheKasmaie et al, 2014), antiaging (Inoue et al, 2003), tonic (Fossati, 1972), antimicrobial (Fontana et al, 2004;Romanelli et al, 2011), immunomodulatory (Mannoor et al, 2009), anti-inflammatory (Kohno et al, 2004(Kohno et al, , 2015, neurotrophic, hypoglicaemic, hypocholesterolaemic (Kamakura et al, 2006;Kashima et al, 2014), vasodilative (Tokunaga et al, 2004), antitumoral, anti-allergic (Okamoto et al, 2003).…”