title: Royal jelly ameliorates insulin resistance in fructose-drinking rats.
abstract: Royal jelly (RJ) is known to contain excellent nutrition and a variety of biological activities. The present study was designed to investigate the effects of RJ on insulin resistance (hyperinsulinemia) in fructose-drinking rats (FDR; insulin resistance animal model). Male Wistar rats (6 weeks old) received 15% fructose solution in drinking water for 8 weeks. FDR showed significant increases in plasma levels of insulin and triglyceride, Homeostasis Model Assessment ratio (HOMA-R, an index of insulin resistance), and systolic blood pressure, but not blood glucose levels, when compared with control rats. RJ (100, 300 mg/kg, p.o.) treatment for 8 weeks significantly decreased the plasma levels of insulin and triglyceride, HOMA-R, without affecting blood glucose or total cholesterol levels and tended to lower systolic blood pressure. In isolated and perfused mesenteric vascular beds of FDR, RJ treatment resulted in a significant reduction in sympathetic nerve-mediated vasoconstrictor response to periarterial nerve stimulation (PNS) and tended to increase the calcitonin gene-related peptide (CGRP) nerve-mediated vasodilator response to PNS, compared with those in untreated FDR. However, RJ treatment did not significantly affect norepinephrine-induced vasoconstriction or CGRP-induced vasodilation. These results suggest that RJ could be an effective functional food to prevent insulin resistance associated with the development of hypertension.
authors.affiliation: Department of Clinical Pharmaceutical Science, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Zamami
authors.forename: Shingo
authors.initials: S
authors.lastname: Takatori
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Goda
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Koyama
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Iwatani
authors.forename: Xin
authors.initials: X
authors.lastname: Jin
authors.forename: Shima
authors.initials: S
authors.lastname: Takai-Doi
authors.forename: Hiromu
authors.initials: H
authors.lastname: Kawasaki
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D001794:Blood Pressure / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D002784:Cholesterol / Q000097:blood; D004326:Drinking; D004558:Electric Stimulation; D005227:Fatty Acids / Q000494:pharmacology*; D005632:Fructose / Q000008:administration & dosage / Q000009:adverse effects*; D006973:Hypertension / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects / Q000294:innervation / Q000502:physiology; D010477:Perfusion; D017933:Peripheral Nervous System / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D014280:Triglycerides / Q000097:blood; D014661:Vasoconstriction / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects; D000099219:Royal Jelly
chemical_list: D001786:Blood Glucose; D002784:Cholesterol; D005227:Fatty Acids; D005632:Fructose; D007328:Insulin; D014280:Triglycerides; D014662:Vasoconstrictor Agents; D000099219:Royal Jelly