Beneficial effect of Flos magnoliae extract on multiple low dose streptozotocin-induced type 1 diabetes development and cytokine-induced beta-cell damage.
In the present study, Flos magnoliae extract (FME) was evaluated to determine if it could protect pancreatic beta-cells against multiple low dose streptozotocin (MLDS) and interleukin-1beta and interferon-gamma. Injection of mice with MLDS resulted in hyperglycemia and hypoinsulinemia, which was confirmed by immunohistochemical staining. However, the induction of diabetes by MLDS was completely prevented when mice were pretreated with FME. FME also effectively protected beta-cells against cytokine toxicity, which was demonstrated by an increase in the viability of rat insulinoma RINm5F cells and by preserved insulin secreting responses to glucose in isolated rat islets. Moreover, cytokine-induced nitric oxide production and iNOS mRNA and protein expression were significantly reduced in RINm5F cells and islets that were preincubated with FME. The molecular mechanism by which FME inhibits iNOS gene expression in in vitro and in vivo appears to involve inhibition of NF-kappaB activation. Taken together, these results reveal the possible therapeutic value of FME for the prevention of type 1 diabetes progression.
Kim
Eun-Kyung
EK
Department of Biochemistry, Medical School and Institute for Medical Sciences, Chonbuk National University, Jeonju, Jeonbuk 561-756, Korea.
Song
Mi-Young
MY
Kim
In-Seob
IS
Moon
Woo Sung
WS
Ryu
Do-Gon
DG
So
Hong-Seob
HS
Park
Raekil
R
Park
Jin-Woo
JW
Kwon
Kang-Beom
KB
Park
Byung-Hyun
BH
D000818:Animals; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D016207:Cytokines / Q000494:pharmacology*; D004247:DNA / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy* / Q000473:pathology; D003922:Diabetes Mellitus, Type 1 / Q000188:drug therapy* / Q000473:pathology; D005260:Female; D005947:Glucose / Q000494:pharmacology; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology*; D031566:Magnolia / Q000737:chemistry*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D016328:NF-kappa B / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000378:metabolism; D008517:Phytotherapy; D010936:Plant Extracts / Q000627:therapeutic use*; D011485:Protein Binding / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D013311:Streptozocin / Q000008:administration & dosage
D016207:Cytokines; D007328:Insulin; D016328:NF-kappa B; D010936:Plant Extracts; D009569:Nitric Oxide; D013311:Streptozocin; D004247:DNA; D052247:Nitric Oxide Synthase Type II; D005947:Glucose