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N o v e m b e r 0 5 - 0 6 , 2 0 1 8 | P h i l a d e l p h i a , U S A
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Obesity Summit 2018 & Diabetes Conference 2018 & Laser Photonics Conference 2018 Biomedical Research | ISSN: 0976-1683| Volume 29
3rd INTERNATIONAL OBESITY SUMMIT AND EXPO
&
&
DIABETES, NUTRITION, METABOLISM & MEDICARE
2nd International Conference on
Joint Event on
OF EXCELLENCE
IN INTERNATIONAL
MEETINGS
YEARS
LASER, OPTICS AND PHOTONICS
World Conference on
JMA Hannan, Biomed Res 2018, Volume 29 | DOI: 10.4066/biomedicalresearch-C7-018
SPIRULINA PLATENSIS STIMULATES GLUCOSE-
STIMULATED INSULIN SECRETION IN PERFUSED
RAT PANCREAS AND BRIN-BD11 CELLS THROUGH
THE cAMP-DEPENDENT PKA PATHWAY
Background and Aim: The antihyprglycemic effects of Spirulina platensis has
previously been reported in rats and humans. In this study the effects of S.
platensis were evaluated on insulin secretion together with exploration of its
mechanism underlying insulin action in isolated perfused rat pancreas and
BRIN-BD11 cells.
Method: The ethanolic extract was successively partitioned using hexane, chlo-
roform, ethylacetate and 1-butanol. Butanol part was dissolved in Krebs-Ringer
bicarbonate (KRB) buffer solution (pH adjusted to 7.4), continuously bubbled
with O2 and perfused, via a cannula into the aorta, to the celiac and mesenteric
arteries of pancreas, isolated by surgery under pentobarbital anesthesia. Insu-
lin in the effluent (collected from a cannula in the portal vein at 1 min interval)
was measured by an ELISA technique with a rat insulin assay kit. Insulin secre-
tory activity was also observed using rat clonal β-cells (BRIN-BD11 cells). For
the studies on the mechanism underlying the insulin secretory activity, 16.8
mM glucose, 30 mM KCl, 50 µM verapamil, 300 µM diazoxide and 10 mM the-
ophylline were used.
Result: The butanol fraction of S. platensis substantially increased insulin re-
lease 1.4 - 4 fold (compared to 5.6mMglucose, P<0.05 – P<0.001) in a dose de-
pendent manner at concentrations 8 to 5000µg/ml from BRIN-BD11 cells. The
butanol fraction produced 10-fold increase in insulin secretion from perfused
pancreas (p<0.01). Perfusion of pancreas with fraction along with 16.8 mM
glucose caused a significant (P<0.01) steep rise of insulin release. The infusion
of diazoxide (300 µM), (a KATP channel opener) and Verapamil (50 µM), (a
voltage-dependent Ca2+ channel blocker) in presence of 16.8 mM glucose did
not significantly affect insulin secretion by S. platensis. Therefore, this study
indicating that effect was not associated with changes in glucose metabolism,
Ca2 + signals or KATP channel activity. The fraction increased insulin secretion
in presence of a cAMP competitor (theophylline, 10mM) significantly (p<0.01)
from perfused pancreas. Diazoxide and verapamil did not significantly inhibit
the insulin enhancing effects of the fraction in BRIN-BD11 cells. The fraction
also stimulated insulin release from chemically depolarized BRIN-BD11 cells
incubated with 30 mM KCl at 16.7 mM glucose. The augmentation of insulin
secretion in completely depolarized conditions and in presence of cAMP com-
petitor (theophylline) is strongly suggestive of an action on second messenger
systems, such as adenylate cyclase-cAMP or phosphatidylinositol pathway, or
on exocytosis.
Conclusion: These data suggest that butanol fraction of S. platensis may be
capable of improving insulin secretion in type 2 diabetes by a variety of actions.
Biography
JMA Hannan earned a PhD in pharmacology from
University of Ulster, UK. He started his research
career as research officer at the department of
pharmacology, research division, BIRDEM, Dhaka,
Bangladesh. He is the founder chairman of the
department of pharmacy, North South University,
Dhaka currently working as professor and head of
the department of pharmacy in the Independent
University, Bangladesh (IUB), Dhaka. He has over
20 years of teaching and research experiences
with 76 full publications and 93 abstracts to his
credit. He published a textbook on ‘Medical and
Pharmaceutical Statistics’.
JMA Hannan
Independent University, Bangladesh