Hydrolase-treated royal jelly attenuates LPS-induced inflammation and IgE-antigen-mediated allergic reaction

Abstract

Background: Royal jelly (RJ) is one of the most effectual and beneficial remedies for human beings and currently utilized in many sectors, ranging from the pharmaceutical and food industries to cosmetic and manufacturing sectors due to RJ possessing many bio-therapeutical activities including anti-tumor, antimicrobial and antioxidant activities, vasodilative and hypotensive activities, as well as growth-stimulating, infection-preventing, anti-hypercholesterolemic and anti-inflammatory activities. However, some reports showing direct consumption of RJ can lead to severe allergic reaction and has been linked with acute asthma, dermatitis, and life-threatening anaphylaxis. Thus, this research purposes to explore the potential anti-inflammatory and anti-allergic activities of hydrolyzed RJ as a function of enzyme and the extent of hydrolysis.Methods: RJ was enzymatically hydrolyzed with three commercial enzymes (AlcalaseÒ, FlavourzymeÒ and ProtamexÒ). Anti-inflammatory activity of the hydrolysates was measured by their inhibitory effect on nitric oxide (NO) production of lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. Anti-allergy was determined from the ability of the hydrolysates to inhibit b-hexsosaminidase (b-HEX) release from RBL-2H3 mast cells. Cytotoxicity was also investigated in both RAW264.7 macrophage cells and RBL-2H3 mast cells.Results: The electrophoretic profiles indicated that AlcalaseÒ and FlavourzymeÒ hydrolysates did not show the presence of proteins causing allergic reaction after 60 mins of hydrolysis while these allergens disappeared from ProtamexÒ hydrolysate at the hydrolysis time of 240 min. It was observed that hydrolyzed RJ showed no toxicity on RAW264.7 and RBL-2H3 cells. With the progression of hydrolysis, IC50 values of NO production inhibition significantly decreased while degree of hydrolysis (DH) was increased in all hydrolyzed samples (p < 0.05). Results of b-HEX release inhibition were found in the same fashion. FlavourzymeÒ hydrolysate at the 240 min time point effectively mitigated the oxidative stress and protected DNA in a dose dependent manner.Conclusions: RJ hydrolysates from FlavourzymeÒ resulted in peptides with anti-inflammatory activity as determined by the inhibition of NO production in LPS-stimulated RAW264.7 macrophage cells and anti-allergic property as measured by the suppression of degranulation of sensitized RBL-2H3 cells. Anti-inflammatory effect may be due to their anti-oxidative capability. Inhibition of b-HEX release may be due to their membrane-stabilizing effects or/and blockade of IgE antibody binding to its receptors.Keywords: anti-inflammation, enzymatic hydrolysate, royal jelly, anti-allergy