Effectiveness of royal jelly supplementation in glycemic regulation:A systematic review

BACKGROUND Royal jelly(RJ)has been observed to have therapeutic properties in diabetic individuals,including the reduction of high blood sugar.This systematic review synthesized existing evidence to investigate the effectiveness of RJ supplementation in managing measures of blood glucose.AIM To determine the effectiveness of RJ supplementation on glycemic responses in healthy and non-insulin dependent diabetic adults,as well as animal models of diabetes.METHODS This was a systematic review employing the PRISMA strategy.Peer-reviewed,published articles were extracted from several databases using key words related to target population,intervention and outcome and hand-selected for inclusion.Included articles proceeded to data extraction phase,where information on target parameters and effectiveness of treatment was summarized.Following this,the risk of bias for each included study was evaluated.Then,the long-term and immediate effectiveness of RJ supplementation in glycemic control were assessed using the Grading of Recommendations,Assessment,Development and Evaluations(GRADE)tool,which rates the quality of evidence.RESULTS Of 168 articles extracted from database searching,eighteen were included for analysis in this systematic review.Across the studies,studied populations,intervention styles and outcome measures were largely heterogeneous.Despite this,the results in studies indicate a general trend of positive effect of RJ in glycemic regulation in vitro and in vivo.Additionally,some dose-dependent glycemic effects were observed,along with some large effect sizes.The risk of bias for human and animal studies is generally low-unclear risk,although lack of blinding is a serious concern in both categories.Overall,as per the GRADE tool,the quality of evidence is low,and very low for long-term and immediate effectiveness of RJ,respectively.A major limitation affecting evidence quality is the heterogeneity among included studies.Fasting blood glucose and glucose clearance appear to be most affected by RJ supplementation.CONCLUSION Quality of evidence suggesting that RJ is an effective modulator of glycemic regulation is low for long-term effects of RJ,and very low for immediate effects.

Bioassay Directed Identification of Royal Jelly’s Active Compounds against the Growth of Bacteria Capable of Infecting Cutaneous Wounds

Antibiotic-resistant bacteria continue to be of major health concern world-wide. Thus, it is of great interest to study the biological properties and determine active compounds in natural products likely to be used as new health remedies. Therefore, the main objective of this work is to test the antibacterial activity of royal jelly samples, defatted royal jelly samples and their ethyl ether extracts against bacteria capable of infecting cutaneous wounds in humans and animals, and to recognize major bioactive compounds by using bioassay directed identification. The microorganisms used in the study were Staphylococcus aureus (including Methicillin-resistant and sensitive strains), Staphylococcus epidermidis, Micrococcus luteus, Streptococcus uberis, Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae. The activity of royal jelly samples to inhibit bacterial growth was assessed by using well-difussion tests. Direct bioautography was used to identify bioactivity, and uv-visible spectroscopy and gas chromatography-mass spectrometry were used to identify bioactive compounds. Overall, royal jelly samples showed higher growth inhibition activity against Gram positive bacteria as compared to Gram negative bacteria. The growth of bacterial strains belonging to the Enterococcus and Streptococcus genders was less affected by the presence of royal jelly than bacterial strains of the Staphylococcus gender did. Compounds with antibacterial activity were found in the ethyl ether extract of royal jelly samples. 10-hydroxy-2-decenoic acid was the major component identified in the purified fraction obtained by bioassay guided fractionation of the ethyl ether extract. In conclusion, bioactivity of royal jelly samples is mainly due to their 10-hydroxy-2-decenoic acid content.