Royal jelly peptides inhibit lipid peroxidation in vitro and in vivo.
ABSTRACT Royal jelly peptides (RJPx) isolated from hydrolysates of water-soluble royal jelly proteins prepared with protease P exhibited significantly stronger hydroxyl radical-scavenging activity (p<0.001), and antioxidant activity against lipid peroxidation (LPO, p<0.001), than did water-soluble royal jelly protein (WSRJP) in vitro. We also investigated the in vivo antioxidant activity of RJPx against ferric nitrilotriacetate (Fe-NTA)-induced LPO. Male Wistar rats were divided into a control group (Group C), an Fe-NTA group (Group Fe), and an Fe-NTA with RJPx group (Group Fe+R). Rats in Group Fe+R were fed RJPx (2 g/kg body weight) daily for 5 wk. Fe-NTA (8 mg Fe/kg body weight) was then intraperitoneally injected, and serum lipid levels were examined 2 h later. Serum total cholesterol (TC) levels were lower (p<0.05) while low-density lipoprotein (LDL) and LPO were significantly higher (p<0.01) in Group Fe than in Group C. TC (p<0.05) and LPO levels (p<0.01) were lower in Group Fe+R than in Group Fe. Our data suggest that RJPx may inhibit LPO both in vitro and in vivo.
Article: Lifespan-extending effects of royal jelly and its related substances on the nematode Caenorhabditis elegans.[show abstract] [hide abstract]
ABSTRACT: One of the most important challenges in the study of aging is to discover compounds with longevity-promoting activities and to unravel their underlying mechanisms. Royal jelly (RJ) has been reported to possess diverse beneficial properties. Furthermore, protease-treated RJ (pRJ) has additional pharmacological activities. Exactly how RJ and pRJ exert these effects and which of their components are responsible for these effects are largely unknown. The evolutionarily conserved mechanisms that control longevity have been indicated. The purpose of the present study was to determine whether RJ and its related substances exert a lifespan-extending function in the nematode Caenorhabditis elegans and to gain insights into the active agents in RJ and their mechanism of action. We found that both RJ and pRJ extended the lifespan of C. elegans. The lifespan-extending activity of pRJ was enhanced by Octadecyl-silica column chromatography (pRJ-Fraction 5). pRJ-Fr.5 increased the animals' lifespan in part by acting through the FOXO transcription factor DAF-16, the activation of which is known to promote longevity in C. elegans by reducing insulin/IGF-1 signaling (IIS). pRJ-Fr.5 reduced the expression of ins-9, one of the insulin-like peptide genes. Moreover, pRJ-Fr.5 and reduced IIS shared some common features in terms of their effects on gene expression, such as the up-regulation of dod-3 and the down-regulation of dod-19, dao-4 and fkb-4. 10-Hydroxy-2-decenoic acid (10-HDA), which was present at high concentrations in pRJ-Fr.5, increased lifespan independently of DAF-16 activity. These results demonstrate that RJ and its related substances extend lifespan in C. elegans, suggesting that RJ may contain longevity-promoting factors. Further analysis and characterization of the lifespan-extending agents in RJ and pRJ may broaden our understanding of the gene network involved in longevity regulation in diverse species and may lead to the development of nutraceutical interventions in the aging process.PLoS ONE 01/2011; 6(8):e23527. · 4.09 Impact Factor