Volume 1 • Issue 4• 1000116
Nat Prod Chem Res
ISSN: 2329-6836 NPCR, an open access journal
Samala and Veeresham, Nat Prod Chem Res 2013, 1:4
DOI: 10.4172/2329-6836.1000116
Research Article Open Access
Enhanced Bioavailability of Glimepiride in the Presence of Boswellic Acids
in Streptozotocin-Induced Diabetic Rat Model
Sujatha Samala* and Ciddi Veeresham
University College of Pharmaceutical Sciences, Kakatiya University, Warangal, AP-506009, India
Abstract
The effect of Boswellia serrata standardized extract (BSE) and Boswellic acids (BA) on the pharmacokinetics and
pharmacodynamics of glimepiride in normal as well as diabetic rats was studied. In normal and streptozotocin induced
diabetic rats the combination of glimepiride with BSE and BA increased all the pharmacokinetic parameters, such as
Cmax, AUC0-n, AUCtotal, t½, MRT and decreased the clearance, Vd markedly as compared with the control group.
In pharmacodynamic studies, the combination of glimepiride with BSE and BA provided signifcant protection against
the diabetes induced alterations in the biochemical parameters. In addition, the combination of glimepiride with BSE
and BA also improved the total antioxidant status and reduced the lipid peroxide levels signifcantly in diabetic rats
compared with BSE, BA and glimepiride alone treated groups. The results revealed that a combination of glimepiride
with BSE and BA led to the enhancement of the bioavailability of glimepiride by inhibiting the CYP2C9 enzyme, which
suggested that boswellia might be benefcial as an adjuvant to glimepiride in a proper dose, in diabetic patients.
*Corresponding author: Sujatha Samala, University College of Pharmaceutical
Sciences, Kakatiya University, Warangal, AP-506009, India, E-mail:
sujathasamala@gmail.com
Received September 11, 2013; Accepted September 23, 2013; Published
September 30, 2013
Citation: Samala S, Veeresham C (2013) Enhanced Bioavailability of Glimepiride
in the Presence of Boswellic Acids in Streptozotocin-Induced Diabetic Rat Model.
Nat Prod Chem Res 1: 116 doi:10.4172/ 2329-6836.1000116
Copyright: © 2013 Samala S, et al. This is an open-access article distributed under
the terms of the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original author and
source are credited.
Keywords: CYP2C9; Boswellia serrata standardized extract;
Boswellic acids; Glimepiride; Pharmacokinetics; Pharmacodynamics
Introduction
Te use of herbal medicine as alternative and/or complementary
therapy in the western world is on the rise and gaining increasing
popularity. As people ofen take diferent herbs in combination
with prescribed modern medication, there is a potential for both
pharmacokinetic and pharmacodynamic interaction [1]. However,
it has been reported that herbal products containing a number of
natural compounds can cause pharmacokinetic and pharmacodynamic
interaction with modern drugs when they were administrated
simultaneously [2,3]. Glimepiride, a sulphonylurea used as an oral
hypoglycemic agent, is widely used for the treatment of type 2 diabetes
mellitus. Te hypoglycemic efect of glimepiride was changed during
co-administration with Carica papaya extract [4], thus there is a need
to study the interaction between glimepiride and other drugs to avoid
adverse efects. In addition, people with diabetes are likely to select
alternative therapy, including herbal medicine, to treat diabetes. For
these reasons, BSE or BA might be used together with antidiabetic
drugs.
Boswellia serrata, known as sallaki or salai guggal or frankincense,
is widely used in India to treat various types of blood disorders,
infammatory health ailments, pain and cardiac debility [5]. Te 6
major active components in B. serrata are α-Boswellic acid, β-Boswellic
acid, 3-Acetyl- α-Boswellic acid, 3-Acetyl- β-Boswellic acid, 11-keto-
β-Boswellic acid and 3-Acetyl-11-keto- β-Boswellic acid. Many studies
have shown that B. serrata and its major component, BA have various
pharmacological activities, such as anti-infammatory [6], anticancer
[7], anti-arthritic [8], immunomodulatory [9], antidiabetic [10] and
analgesic [11].
Tere are several in vitro reports of BSE or BA on inhibition of
microsomal enzyme system (CYP1A2, 2C8, 2C9, 2D6 and 3A4) and
may lead to change in the bioavailability of concomitant drugs [12].
Hence, there is the possibility of BSE or BA for the metabolic inhibition
of glimepiride, which is also completely metabolized by CYP2C9
microsomal liver enzymes [13].
In view of the efect of BSE or BA on CYP enzymes especially
on CYP2C9 and also antidiabetic property, its presence in herbal
antidiabetic preparations may infuence the bioavailability of
glimepiride, particularly because the later is metabolized by CYP2C9.
Terefore, the aim of the present investigation was to study the efect
of BSE or BA on bioavailability and pharmacodynamics of glimepiride.
Experimental
Drugs and chemicals
Glimepiride and gliclazide were obtained as gif samples from Dr.
Reddy’s laboratories (Hyderabad, India). Methanol (HPLC-grade),
potassium dihydrogen orthophosphate and orthophosphoric acid of
AR grade (99.5%) were procured from Merck Specialties Pvt. Ltd.,
Mumbai. Boswellic acid (BA) was purchased from Yucca Enterprises,
Mumbai. Boswellia serrata standardized extract (BSE) was obtained as
gif sample from Amsar Pvt. Ltd., Indore. Ascorbic acid, α, α-diphenyl-
β-picrylhydrazyl (DPPH), 1,1,3,3-tetraethoxy propane (TEP),
thiobarbituric acid and streptozotocin (STZ) were purchased from Hi
Media Laboratories Pvt. Ltd, Mumbai. Merck analytical kits were used
to estimate the serum biochemical parameters. Water for analytical
purpose is double distilled, fltered by using direct-Quv millipore and
sonicated for removing air bubbles. All other chemicals used were of
analytical grade.
Maintenance of animals
Male Albino rats of Wistar strain weighing 180-250 g were
purchased from Mahaveera enterprises, Hyderabad, India and used
for the studies afer obtaining the permission from institutional
animal ethical committee (CPCSEA Reg. No.146/1999). Te animals
were housed in standard polypropylene cages and maintained under
standard laboratory conditions (12:12 h light and dark cycle; at an
ambient temperature of 25 ± 5°C; 35-60% of relative humidity). Te
animals were fed with standard rat pellet diet and water ad libitum.
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ISSN: 2329-6836
Natural Products Chemistry & Research