[Ameliorative effect of propolis on insulin resistance in Otsuka Long-Evans Tokushima Fatty (OLETF) rats].
Propolis is known to have abundant bioactive constituents and a variety of biological activities. To investigate the effect of Brazilian propolis on insulin resistance, 10-week-old Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a non-insulin-dependent type 2 diabetic model, were treated for 4 weeks with propolis (100 and 300 mg/kg, p.o.) or vehicle (control). Propolis treatment significantly decreased the plasma levels of insulin and insulin resistance index (Homeostasis Model Assessment-Insulin Resistance; HOM-IR), without affecting blood glucose levels and tended to lower systolic blood pressure compared with the control. In isolated and perfused mesenteric vascular beds of OLETF rats, propolis treatment resulted in significant reduction of sympathetic nerve-mediated vasoconstrictor response to periarterial nerve stimulation (PNS) and tended to increase calcitonin gene-related peptide (CGRP) nerve-mediated vasodilator response to PNS compared with in vehicle-treated OLETF rats. However, propolis treatment did not significantly affect the vasoconstrictor and vasodilator response to noradrenaline, CGRP, acetylcholine, and sodium nitroprusside. These results suggest that propolis could be an effective and functional food to prevent development of insulin resistance.
Department of Clinical Pharmaceutical Science, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University.
Yoshito
Y
Zamami
Hiroki
H
Fujiwara
Miho
M
Hosoda
Hayato
H
Hino
Kazuhiro
K
Hirai
Kazuaki
K
Okamoto
Xin
X
Jin
Shingo
S
Takatori
Shima
S
Doi-Takaki
Hiromu
H
Kawasaki
D000284:Administration, Oral; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008638:Mesenteric Arteries / Q000187:drug effects / Q000294:innervation; D011429:Propolis / Q000008:administration & dosage* / Q000494:pharmacology*; D051381:Rats; D020334:Rats, Inbred OLETF; D013564:Sympathetic Nervous System / Q000502:physiology; D013599:Systole / Q000187:drug effects; D013997:Time Factors; D014661:Vasoconstriction / Q000187:drug effects
D001786:Blood Glucose; D007328:Insulin; D011429:Propolis