Royal jelly (RJ) is a secretion of the mandibular and hypopharyngeal glands of worker bees Apis mellifera (Hymenoptera, Apidae) involved in the sexual determination and longevity of the queen bee. This secretion is a yellowish, creamy, and acidic material with a slightly pungent odor and taste. RJ is fed temporarily (up to and no more than 3 days) to the brood of workers and drones, but it is a sole food of the queen bee for both her larval and adult life. RJ has been demonstrated to possess several pharmacological activities in vitro, in vivo in experimental animals, and through clinical studies, including vasodilative and hypotensive activities, increase in growth rate, disinfectant action, antitumor activity, and antimicrobial, antihypercholesterolemic, and anti-inflammatory activities. Moreover, recently, a specific immunomodulatory action as well as estrogen-like effects has been reported, while its potential therapeutic value in inhibiting joint destruction in rheumatoid arthritis has been also proved. Earlier biological investigations have shown that royal jelly has insulin-like activity; however, only through a very recent clinical trial these findings were assured.
Therefore, royal jelly has been widely used in commercial medical products, health foods, and cosmetics in many countries for more than 35 years.
The unique and chemically most interesting feature of RJ among many other compounds is its fatty acids. Unlike fatty acids of most animal and plant materials, which consist mainly of triglyceride fatty acids each having 14–20 carbon atoms, RJ fatty acids are short-chained 8–12-carbon free fatty acids that are usually either hydroxy fatty acids or dicarboxylic acids. The major fatty acid in RJ is 10-hydroxy-2-decenoic acid (10-HDA). Moreover, many studies have been published on its very important biological peptide content.
The aim of this study is to review the chemistry and all the reported till now bioactivities of this “hot” natural product since 1852, when the first scientific studies for royal jelly appeared.