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ISSN : 2395-535X (print), ISSN: 2395-5368 (Online)

JOS

Published by ISTF Publication Division Press. All rights reserved. Email:[email protected]

Double-Diffusive Magneto–Rotatory Convection in Couple-Stress Fluid

Through Porous Medium

Sunil Jayant

Indian Science and Technology Foundation (ISTF), C-1/31, Yamuna Vihar, New Delh-110053, India

* Corresponding author :

Sunil Jayant, Indian Science and Technology Foundation (ISTF), C-1/31, Yamuna Vihar, New Delh-110053, India, [email protected], Ph.: +918826423598

article info

Article history: Received 2 March 2017

Revised

Accepted

Available online 31 March 2017

ABSTRACT

The double-diffusive convection in a couple-stress fluid layer heated and soluted from below in porous medium is considered in the presence of uniform vertical magnetic field and uniform rotation. For the case of stationary convection, the stable solute gradient and rotation have stabilizing effects on the system. In the presence of rotation, the medium permeability has a destabilizing (or stabilizing) effect whereas magnetic field and couple-stress parameter have stabilizing (or destabilizing) effect on the system. On the other hand, in the absence of rotation, medium permeability has a destabilizing effect whereas magnetic field and couple-stress parameter have a stabilizing effect. The dispersion relation is also analyzed numerically. The stable solute gradient, rotation and magnetic field introduce oscillatory modes in the system, which were nonexistent in their absence.

Keywords:

Double-diffusive convection

Couple-stress fluid

Porous medium

Uniform vertical rotation

Uniform vertical magnetic field

INTRODUCTION

The theoretical and experimental results on

thermal convection in a fluid layer, in the

absence and presence of rotation and magnetic

field have been given by Chandrasekhar (1).

The problem of thermohaline convection in a

layer of fluid heated from below and subjected

to a stable salinity gradient has been

considered by Veronis (2). The buoyancy force

can arise not only from density differences due

to variations in temperature but also from those

due to variations in solute concentration.

Double-diffusive convection problems arise in

oceanography, limnology and engineering.

Examples of particular interest are provided by

ponds built to trap solar heat (3) and some

Antarctic lakes (4). The physics is quite similar

in the stellar case in that helium acts like salt in

raising the density and in diffusing more

slowly than heat. The conditions under which

convective motions are important in stellar

atmospheres are usually far removed from

consideration of a single component fluid and

rigid boundaries, and therefore it is desirable to

consider a fluid acted on by a solute gradient

and free boundaries.

The problem of double-diffusive

convection in fluids in a porous medium is of

importance in geophysics, soil sciences,

ground water hydrology and astrophysics. The

development of geothermal power resources

has increased general interest in the properties

of convection in porous media. The scientific

importance of the field has also increased

because hydrothermal circulation is the

dominant heat-transfer mechanism in young

oceanic crust (5). Generally, it is accepted that

comets consist of a dusty ‘snowball’ of a

mixture of frozen gases which in the process of

their journey changes from solid to gas and

vice- versa. The physical properties of comets,

meteorites and interplanetary dust strongly

suggest the importance of porosity in the

astrophysical context (6).



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The effect of a magnetic field on the

stability of such a flow is of interest in

geophysics, particularly in the study of Earth’s

core where the Earth’s mantle, which consists

of conducting fluid, behaves like a porous

medium which can become convectively

unstable as a result of differential diffusion.

The other application of the results of flow

through a porous medium in the presence of a

magnetic field is in the study of the stability of

a convective flow in the geothermal region.

Stommel and Fedorov (7) and Linden (8) have

remarked that the length scales characteristics

of double-diffusive convective layers in the

ocean may be sufficiently large that the Earth’s

rotation might be important in their formation.

Moreover, the rotation of the Earth distorts the

boundaries of a hexagonal convection cell in a

fluid through a porous medium and the

distortion plays an important role in the

extraction of energy in the geothermal regions.

Brakke (9) explained a double- diffusive

instability that occurs when a solution of a

slowly diffusing protein is layered over a

denser solution of more rapidly diffusing

sucrose. Nason et al. (10) found that this

instability, which is deleterious to certain

biochemical separations, can be suppressed by

rotation in the ultracentrifuge.

The theory of couple-stress fluid has

been formulated by Stokes (11). One of the

applications of couple-stress fluid is its use to

the study of the mechanisms of lubrications of

synovial joints, which has become the object of

scientific research. A human joint is a

dynamically loaded bearing which has articular

cartilage as the bearing and synovial fluid as

the lubricant. When a fluid film is generated,

squeeze- film action is capable of providing

considerable protection to the cartilage surface.

The shoulder, ankle, knee and hip joints are the

loaded – bearing synovial joints of the human

body and these joints have a low friction

coefficient and negligible wear.

Normal synovial fluid is a viscous,

non-Newtonian fluid and is clear or yellowish.

According to the theory of Stokes (11), couple-

stresses appear in noticeable magnitudes in

fluids with very large molecules. Since the

long chain hyaluronic acid molecules are found

as additives in synovial fluids, Walicki and

Walicka (12) modeled the synovial fluid as a

couple-stress fluid. The synovial fluid is the

natural lubricant of joints of the vertebrates.

The detailed description of the joint lubrication

has very important practical implications.

Practically all diseases of joints are caused by

or connected with malfunction of the

lubrication. The efficiency of the physiological

joint lubrication is caused by several

mechanisms.

The synovial fluid is due to its content

of the hyaluronic acid, a fluid of high viscosity,

near to gel. Goel et al. (13) have studied the

hydromagnetic stability of an unbounded

couple-stress binary fluid mixture under

rotation with vertical temperature and

concentration gradients. Sharma et al. (14)

have considered a couple - stress fluid with

suspended particles heated from below. In

another study, Sunil et al. (15) have considered

a couple- stress fluid heated from below in a

porous medium in the presence of a magnetic

field and rotation. Kumar et al. (16) have

considered the thermal instability of layer of

couple-stress fluid acted on by a uniform

rotation, and have found that for stationary

convection the rotation has a stabilizing effect

whereas couple-stress has both stabilizing and

destabilizing effects.

Keeping in mind the importance in

geophysics, soil sciences, ground water

hydrology, astrophysics and various

applications mentioned above, the double -

diffusive convection in couple-stress fluid in a

porous medium in the presence of uniform



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rotation and uniform magnetic field has been

considered in the present paper.

FORMULATION OF THE PROBLEM

AND PERTURBATION EQUATIONS

Here we consider an infinite,

horizontal, incompressible couple-stress fluid

layer of thickness d, heated and soluted from

below so that, the temperatures, densities and

solute concentrations at the bottom surface z =

0 are T0, 0 and C0 and at the upper surface z =

d are Td, d and Cd respectively, and that a

uniform temperature gradient

dz

dT and a

uniform solute gradient /

dz

dC are

maintained. The gravity field )g,0,0(g

, a

uniform vertical magnetic field )H,0,0(H

and a

uniform vertical rotation ),0,0(

pervade

the system. This fluid layer is assumed to be

flowing through an isotropic and homogeneous

porous medium of porosity and medium

permeability k1.

Let p, , T, C, , /, g, , e and

)w,v,u(q

denote respectively, the fluid

pressure, density, temperature, solute

concentration, thermal coefficient of

expansion, an analogous solvent coefficient of

expansion, gravitational acceleration,

resistivity, magnetic permeability and fluid

velocity. The equations expressing the

conservation of momentum, mass,

temperature, solute concentration and equation

of state of couple-stress fluid are

00 ρ

δρ1gp

ρ

1q).q(

1

t

q1

qHHq

k

e 2

4

1

0

2

0

/

1

,

(1)

0q.

, (2)

TT.qt

TE 2

, (3)

CC.qt

CE 2//

, (4)

= 0 [1- (T - T0)+ / (C - C0)],(5)

where the suffix zero refers to values at the

reference level z = 0 and in writing Eq.(1), use

has been made of Boussinesq approximation.

The magnetic permeability e, the kinematic

viscosity , couple-stress viscosity /, the

thermal diffusivity and the solute diffusivity

/ are all assumed to be constants.

The Maxwell’s equations yield

HqHdt

Hd 2

, (6)

and

,0H

(7)

where

q

tdt

d 1 stands for the

convective derivative. Here E =

i0

ss

C

C)1( is a constant and E

/ is a

constant analogous to E but corresponding to

solute rather that heat; s, Cs and o , Ci stand

for density and heat capacity of solid (porous

matrix) material and fluid, respectively. The

steady state solution is

q

(0, 0 , 0 ), T = T0 - z, C = C0 - / z, =

0 (1 + z - /

/ z ) . (8)

Here we use linearized stability theory and

normal mode analysis method. Consider a

small perturbation on the steady state solution,

and let p, , , , )h,h,h(h zyx

and q

(u, v,

w) denote, respectively, the perturbations in

pressure p, density , temperature T, solute

concentration C, magnetic field )0,0,0(H

and

velocity q

(0, 0, 0). The change in density ,



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caused mainly by the perturbations and in

temperature and concentration, is given by

= - 0 ( / ). (9)

Then the linearized perturbation equations

become

q

k

1)(gp

1

t

q1 2

0

/

1

/

0

q

2Hh

4 0

e ,(10)

q.

=0, (11)

2wt

E , (12)

2/// wt

E , (13)

hqHt

h

2

, (14)

and

h.

=0, (15)

THE DISPERSION RELATION

Analyzing the disturbances into normal

modes, we assume that the perturbation

quantities are of the form

[w,hz,,, ,] = [W(z), K(z), (z), (z), Z(z),

X (z)]exp(ikxx + ikyy + nt) , (16)

where kx, ky are the wave numbers along the x-

and y- directions respectively, k= ( 2

y

2

x kk )

is the resultant wave number and n is the

growth rate which is, in general, a complex

constant. = y

u

x

v

and =

y

h

x

hxy

stand for the z-components of vorticity and

current density, respectively.

Expressing the coordinates x, y, z in

the new unit of length d and letting a = kd,

=

2nd, p1 =

(Prandtl number), p2 =

(magnetic Prandtl number), q = /

(Schmidt

number) , 2

1

d

kP ( dimensionless medium

permeability) and F = νdρ

μ2

0

/

(dimensionless

couple-stress parameter ), Eqs. (10)- (15),

using (16), yield

,02

4)(

1 322/

222222

DZ

dDKaD

HddgaWaDaD

P

F

P o

e

(17)

,2

4

1 22 DWd

DXHd

ZaDP

F

P o

e

(18)

K)paD( 2

22 = ,DWHd

(19)

X)paD( 2

22 = ,DZHd

(20)

)EpaD( 1

22= W

d 2

, (21)

)qEaD( /22= W

d/

2/

. (22)

Consider the case where both boundaries are

free as well as perfect conductors of both heat

and solute concentration, while the adjoining

medium is perfectly conducting. The case of

two free boundaries is a little artificial but it

enables us to find analytical solutions and to

make some qualitative conclusions. The

appropriate boundary conditions, with respect

to which Eqs. (17)- (22) must be solved are

W = D2W = X = DZ = 0, = 0 , Γ = 0 , at z

= 0 and z = 1 ,

DX = 0, K = 0 on a perfectly conducting

boundary and X = 0 and hx, hy, hz are

continuous with an external vacuum field on a

non-conducting boundary. (23)

The case of two free boundaries,

though little artificial, is the most appropriate

for stellar atmospheres (17). Using the above



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boundary conditions, it can be shown that all

the even order derivatives of W must vanish

for z = 0 and z = 1 and hence the proper

solution of W charactering the lowest mode is

W = W0 sin z , (24)

where

W0 is a constant.

Eliminating , , K, Z and X between

Eqs. (17) – (22) and substituting the proper

solution W = W0 sin z , in the resultant

equation, we obtain the dispersion relation

)qiEx1(

)iEpx1(SQ)ipx1()x1(

P

F

P

1i)iEpx1(

x

x1R

1

/

111112

11111

+

11211

12111

Q)ipx1()x1(P

F

P

1ix

)ipx1)(iEpx1(T

(25)

where

R1= 4

4dg

,S1= 4/

4// dg

,

2

0

22

e1

4

dHQ

, ,d2

T

2

2

2

1

2

2ax

,

21i

, F1=

2F

and. P = 2Pl .

THE STATIONARY CONVECTION

When the instability sets in as

stationary convection, the marginal state will

be characterized by = 0. Putting = 0, the

dispersion relation (25) reduces to

11

2

1111

2

1

Q)x1()x1(P

F

P

1x

)x1(TSQ)x1()x1(

P

F

P

1

x

)x1(R

.

(26)

To investigate the effects of stable solute

gradient, rotation, magnetic field, couple-stress

parameter and medium permeability, we

examine the behaviour of1

1

Sd

Rd,

1

1

Td

Rd,

1

1

Qd

Rd,

1

1

Fd

Rd and

Pd

Rd 1 analytically.

Equation (26) yields

1Sd

Rd

1

1 , (27)

11

2

1

1

Q)x1()x1(P

F

P

1x

)x1(

dT

dR, (28)

2

11

1

2

1

1

Q)x1()x1(P

F

P

1

T1

x

)x1(

dQ

dR , (29)

2

11

1

4

1

1

Q)x1()x1(P

F

P

1

T1

xP

)x1(

dF

dR , (30)

2

11

1

2

3

1

Q)x1()x1(P

F

P

1

T1

xP

)x1(

dP

dR (31)

Equations (27) and (28) imply that, for

stationary convection, stable solute gradient

and rotation have stabilizing effects on the

system. Equations (29)- (31) shows that in the

absence of rotation (T1 = 0 ), 1

1

Qd

Rd and

1

1

Fd

Rd

is always positive whereas Pd

Rd 1 is always

negative which means that magnetic field and

couple-stress parameter have a stabilizing

effect, whereas, medium permeability has a

destabilizing effect on the system in the

absence of rotation. For a rotating system, the

magnetic field and couple-stress parameter

have a stabilizing ( or destabilizing ) effect and

the medium permeability has a destabilizing (

or stabilizing) effect on instability of couple-



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stress rotating fluid in porous medium in

hydromagnetics if

T1 < ( or > )

.Q)x1()x1(P

F

P

12

11

(32)

The dispersion relation (26) is also analyzed

numerically for various values of S1, T1, P, F1

and Q1. It is also evident from Figures 1- 5 that

stable solute gradient and rotation have

stabilizing effects whereas magnetic field,

couple-stress parameter and medium

permeability have both stabilizing and

destabilizing effects on the system.

STABILITY OF THE SYSTEM AND

OSCILLATORY MODES

Here we examine the possibility of

oscillatory modes, if any, on the stability

problem due to the presence of stable solute

1 2 3 4 50

50

100

150

200

250

300

350

400

450

500

R1

xFigure 1: The variation of Rayleigh number R

1 with x for S

1=10, F

1=5, Q

1=20, P=5

and T1=200, 400 and 600.

T1=200

T1=400

T1=600

1 2 3 4 50

100

200

300

400

500

R1


1 with x for F

1=5, Q

1=20, P=5, T

1=200

and S1= 10, 15 and 20.

S1=10

S1=15

S1=20

0.5 1.0 1.5 2.0 2.50

200

400

600

800

R1


1 with x for S

1=10, F

1=5, T

1=200, P=5

and Q1 =20, 40 and 60.

Q1=20

Q1=40

Q1=60

0.5 1.0 1.5 2.0 2.50

100

200

300

400

500

R1


1 with x for S

1=10, T

1=200, Q

1= 20, P=5

and F1= 5, 10 and 15.

F1=5

F1=10

F1=15

0.5 1.0 1.5 2.0 2.50

50

100

150

200

250

300

350

400

450

500

R1


1 with x for S

1=10, T

1=200, Q

1=20, F

1=5

and P=2, 5 and 8.

P=2

P=5

P=8



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gradient, magnetic field and rotation.

Multiplying Eq. (17) by W*, the complex

conjugate of W, integrating over the range of z

and making use of Eqs. (18) – (22) together

with the boundary conditions (23), we obtain

6

*/

5/

//2

4

*

13

2

21 IqEIga

IEpIga

IP

FI

P

1

,0I4

pdI

4

dI

P

1dI

P

FdIpI

412

0

2

2

e11

0

2

e10

*2

9

2

8

*

27

0

e

(33)

where

and

* is the complex conjugate of . The

integrals I1 – I12 are all positive definite.

Putting = r + ii and equating the real

and imaginary parts of Eq. (33), we obtain

It is evident from (35) that r is positive or

negative. The system is, therefore, stable or

unstable. It is clear from (36) that i may be

zero or non-zero, meaning that the modes may

be non-oscillatory or oscillatory.

From Eq. (36), it is clear that i is zero

when the quantity multiplying it is not zero and

arbitrary when this quantity is zero.

If i 0 , then Eq. (36) gives

Equation (38) on using Rayleigh –Ritz

inequality gives

9

2

10

2

11

0

2

122

0

2

2

221

0

2

2

322

42|| I

P

FdI

P

dI

dIp

d

F

P

a

adzW

a

a eer

dz|W|F

PgI

2I

P

1I

gaI

4

1

0

2

1r

15/

//2

7

0

e

.

(39)

Therefore, It follows from Eq. (39) that

9

2

10

2

11

0

2

e122

0

2

er

2

221

0

24

IP

FdI

P

dI

4

dIp

2

d

F

P

a

adz|W|

F

Pg

4

27

1r

15/

//2

7

0

e I2I

P

1I

gaI

4

0, (40)

since minimum value of

2

322

a

a with

respect to a2 is

4

27 4.

Now, let r 0, we necessary have from (40)

that

F

Pg

>

4

27 4 (41)

Hence, if

F

Pg

4

27 4, (42)

then r < 0. Therefore, the system is stable.

Therefore, under condition (42), the system is

stable and under condition (41) the system

becomes unstable.



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In the absence of stable solute gradient,

rotation and magnetic field, Eq. (36) reduces to

0IEpgaI

41

2

1i

, (43)

and the terms in brackets are positive definite.

Thus i = 0, which means that oscillatory

modes are not allowed and the principle of

exchange of stabilities is valid for the couple-

stress fluid for a porous medium, in the

absence of stable solute gradient, rotation and

magnetic field. The oscillatory modes are

introduced due to the presence of stable solute

gradient, rotation and magnetic field, which

were non-existent in their absence.

CONCLUSIONS

The effect of a uniform vertical

magnetic field and uniform rotation on the

double-diffusive convection in a couple-stress

fluid heated and soluted from below in porous

medium is considered in the present paper. The

investigation of double-diffusive convection is

motivated by its interesting complexities as a

double diffusion phenomenon as well as its

direct relevance to geophysics and

astrophysics. The double-diffusive convection

problems arise in oceanography, limnology

and engineering. Ponds built to trap solar heat

and some Antartic lakes provide examples of

particular interest.

The main conclusions from the analysis of this

paper are as follows:

(a) For the case of stationary

convection the following observations

are made:

(i) The stable solute gradient and

rotation have stabilizing effect on

the system.

(ii) In the presence of rotation, the

medium permeability has a

destabilizing (or stabilizing) effect

whereas magnetic field and couple-

stress parameter have stabilizing (or

destabilizing) effect on the system.

(iii) In the absence of rotation, the

medium permeability has a

destabilizing effect whereas

magnetic field and couple-stress

parameter have a stabilizing effect.

(b) It is also observed from Figures 1-5

that stable solute gradient and rotation

have stabilizing effects whereas

magnetic field, couple-stress parameter

and medium permeability have both

stabilizing and destabilizing effects on

the system.

(c) It is observed that stable solute

gradient, rotation and magnetic field

introduce oscillatory modes in the

system, which were non-existent in

their absence.

(d) It is found that if F

Pg l

4

27 4,

the system is stable and under the

condition F

Pg l

>

4

27 4, the

system becomes unstable.

(e) In the absence of stable solute gradient,

rotation and magnetic field, oscillatory

modes are not allowed and the principle

of exchange of stabilities is valid.

ACKNOWLEDGEMENTS

SJ thanks to ISTF for all supports.

REFERENCES

1. Chandrasekhar, S. (2013) Hydrodynamic

and hydromagnetic stability. Courier

Corporation.

2. Veronis, G. (1965) On finite amplitude

instability in thermohaline convection. J.

Marine Res. 23, 1-17



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3. Tabor, H. and Matz, R. (1965) A status

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8. Linden, P. F. (1974) Salt fingers in a steady

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27

9. Brakke, M. K. (1955) Zone electrophoresis

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centrifugation. Biopolymers, 7(2), 241-249.

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fluids. Phys. fluids, 9(9), 1709-1715

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effect in the squeeze film of a couple-

stress fluid in biological bearings. Applied

Mechanics and Engineering, 4(2), 363-

373

13. Goel, A.K., Agarwal, S.C., and Agarwal,

G.S. (1999) Hydromagnetic stability of an

unbounded couple-stress binary fluid

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concentration gradients with rotation,”

Indian J. Pure Appl. Math., 30, 991.

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Chandel, R. S. (2002) On couple-stress

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287-298

15. Sharma, R. C., and Pal, M. (2002) On a

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Effect of rotation on thermal instability in

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I. Astrophys. J. 141, 1068-1090



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A study on the efficacy of Nelumbo nucifera gaertn in the management of

Type-2 diabetes mellitus

Dr. Nazma Ahmed1*, Dr. Bishnu Prasad Sarma

2*

1,2 Department of Kayachikitsa, Govt. Ayurvedic College Hospital, Guwahati-14, Assam and Dean, Faculty of Ayurvedic Medicine, Srimanta Sankardeva University

of Health Sciences.

* Corresponding author :

Dr. Nazma Ahmed , Department of Kayachikitsa, Govt. Ayurvedic College Hospital, Guwahati-14, Assam, [email protected]

Article info

Article history: Received 2 February 2017

Revised

Accepted

Available online 31 March 2017

ABSTRACT

Time and again we have turned to nature for the cure of various diseases and even in Ayurveda and other Indian literature we find mention of the use of plants in treatment of various ailments. India has about 45,000 plant species of which several thousands have been claimed to possess medicinal properties. One such plant is the Lotus plant (Nilumbo nucifera) whose medicinal composition includes-Eight categories : flavonoids, penolics, alkaloids, triterpenoids, polysaccharides, superoxide dismutase (SOD), fiber and volatile oils (Zhou et al , 2007).The medicinal use of lotus rhizome has also been mentioned ancient Ayurvedic scholars like Charak and Susruta etc. in the treatment of diabetes mellitus.Diabetes mellitus is a condition of impaired insulin secretion and variable degree of peripheral insulin resistance leading to hyperglycemia. For the treatment of diabetes mellitus a clinical trial was done at Govt. Ayuredic College Hospital by using the powder of rhizome of lotus plant and so far yielding good results.

Keywords:

Hyperglycemia

Hypoglycemic

Lotus rhizome

Flavonoids

Triterpenoids

INTRODUCTION

Diabetes Mellitus is a condition where there is

impaired insulin secretion and variable degree

of peripheral insulin resistance leading to

Hyperglycemia. According to Ayurveda there

are triangular approach to treat diabetes

mellitus i.e. diet, drugs and exercise that

reduce glucose levels.

Type–2 diabetes mellitus is a

heterogeneous group of disorders usually

characterized by variable degree of insulin

resistance, impaired insulin secretion and

increased glucose production. Distinct genetic

and metabolic defects in insulin action and / or

secretion give rise to the common phenotype

of hyperglycemia in Type – 2 diabetes

mellitus.

Diabetes mellitus is a chronic condition in

which patients may turn to alternative remedies

that are, purported to improve glycemic control

.The disease is characterized by symptomatic

glucose in tolerances as well as alterations in

lipid and protein metabolism. The long term

complications of untreated or effectively

treated diabetes include retinopathy,

nephropathy and peripheral neuropathy. In

addition, diabetic patients have an increased

risk of cardiovascular disease and stroke.

Therefore there is a strong need for safe and

effective oral hypoglycemic agents that

provide the clinician with a wider range of

options for preventing, treating and managing

diabetes. Ayurveda, the holistic system of

medicine provides a good support to the

diabetic people. There are lots of medicinal

plants which are used as an anti-diabetic. They

help to minimize the various signs and

symptoms along with their complications.

Since ancient time, plants have been an

exemplary source of medicine. Ayurveda and

other Indian literature mention the use of

plants in treatment of various human ailments.



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India has about 45,000 plants species and

among them several thousands have been

claimed to possess medicinal properties.

Research conducted in last few decades on

plants mentioned in ancient literature or used

traditionally for diabetes have shown anti-

diabetic property. The present paper reviews

one of such plant that has been mentioned in

classic text of Ayurveda i.e. the Samhita of

Charaka (Cha/Chi/6/31-32), Sushruta

(Su/Chi/11/9-10) and Vagbhata

(A.S.Chi/14/20).

Here , in this work the medicinal plant

which has been selected is a good

hypoglycemic as well as hypolipidemic in

action is Lotus (Nelumbo Nucifera Gaertn).

A plant Nelumbo Nucifera belongs to

the family of Nelumbonaceae, which has

several common names ( e.g Indian lotus ,

Chinese Water lily and sacred lotus) and

synonyms (Neelumbium Nelumbo, N.

Spaceciosa , N, speciosum and nymphaea

Nelumbo). Lotus perennial large and

rhizomatous aquatic herb with slender ,

elongated branched , creeping stem consisting

of nodal roots . The discovered medicinal

composition of lotus mainly include eight

categories : flavonoids, penolics , alkaloids ,

triterpenoids, polysaccharides, superoxide

dismutase (SOD), fiber and volatile oils (Zhou

et al, 2007). The rhizome extract has anti

diabetic (Mukharjee at al 1997 a) and anti

inflammatory properties due to presence of

asteroidal triterpenoid . Rhizome are used for

pharyngopathy , pectoralgia ,spermatoria,

leucoderma, small pox, diarrehoea, dysentery

and cough. Mukharjee et al 1997 B reported

that oral administration of the ethanolic extract

of lotus rhizomes markedly reduced the blood

sugar level of normal, glucose fed

hyperglycemic and streptozotocin induced

diabetic rats.This herb is used in our North

East Region especially in Monipur as a diet

and local remedy of diabetes since long back.

METHODS

A total number of 120 patients newly

diagnosed have been randomly screened from

Govt. Ayurvedic College and Hospital,

Guwahati, Assam, and Capital State

Dispensary, Dispur, Assam.

Drug Application :

• All the patients registered for clinical

study have been treated with a preparation

of Nelumbo Nucifera Rhizome Powder and

have been given at the dose of 3gm twice

daily before meal.

• All selected cases have been advised to

take the trial drug along with the diet

control (with specific diet chart)

• All cases investigated methodologically

before and after treatment to evaluate the

hypoglycemic action.

• All the cases have been assessed at an

interval of 30 days for clinical and

investigative follow-up for at least three

months

The Trial Methodology adopted for study was

open trial in one group and treated with

preparation of Lotus Rhizome powder was

given in the dose of 3gm twice daily before

meal and advised to take the trial drug with

diet control. All cases was investigated before

and after treatment to evaluate the

hypoglycaemic action in the interval of 30

days for clinical and investigative follow up

for at least 3 consecutive sequences.

RESULT

Statistical evaluation was done in laboratorial

parameters after calculating mean, SD, SE, Z

and P values.

Effect of the drugs has been observed

by calculating the Z value of mean difference

between before and after treatment.

Effect of treatment on fasting blood

sugar (FBS) (Table-1) shows statistically



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highly significant. FBS values before treatment

i.e. Mean ± SD is 164± 30.4 and values after

treatment are : Mean ± SD is 141± 15.7, SE

value is 3.76 and Z value is 6.1 which is highly

significant (P<0.01).

Table 1. Effect of treatment on FBS (Fasting

Blood Sugar) in120 cases of TypeDiabetes

Mellitus.

Mean SD SE

Z

value Result

Before

Treatment 164 30.4

3.76 6.1 P<0.01 After

Treatment 141 15.7

Effect of treatment on Post Prandial Blood

Sugar (PPBS) (Table-2) shows statistically

highly significant. PPBS values before

treatment i.e. Mean ± SD is 221 ±28.6 and

values after treatment are : Mean ± SD is 193 ±

18.8, SE value is 3.9 and Z value is 7.1

which is highly significant (P<0.01).

Table 2. Effect of treatment on PPBS (Post

Prandial Blood Sugar) in120 cases of Type-2

Diabetes Mellitus.

Mean SD SE

Z

value

Result

Before

Treatment 221 28.6

3.90 7.1 P<0.01 After

Treatment 193 18.8

Effect of treatment on HbA1c is as follows

(Table-3) , before treatment : Mean ± SD is 7.7

± 0.8 and after treatment : Mean ± SD is 6.8 ±

0.40, SE value is 0.11 and Z Value is 8.1

which is also very highly significant (P<0.01).

Table 3. Effect of treatment on HbA1c

(Glycosylated Hemoglobin) in120 cases of

Type-2 Diabetes Mellitus.

Mean SD SE Z

value Result

Before

Treatment 7.7 0.8

0.11 8.1 P<0.01 After

Treatment 6.8 0.4

Effect of Treatment:

From the above observation regarding effect of

treatment on Fasting Blood Sugar (FBS) and

PPBS, it has been seen that decrement of blood

sugar is more in PPBS comparing to that of

FBS. So we can conclude that the effect of

drug is more in PPBS not only in terms of

increased peripherals glucose utilization but

we cannot deny the drugs have also some role

in insulin secretion and by decreasing glucose.

DISCUSSION AND CONCLUSION

The results of the therapeutic trial showed that

the trail of Nelumbo Nucifera was very

effective in controlling the blood sugar level.

The level of fasting blood sugar and post

prandial blood sugar was significantly reduced

upon treatment with the trial drug of Nelumbo

Nucifera. The level of Glycosylated

hemoglobin was significantly reduced showing

good glycemic control. The folkloric use of

Nelumbo Nucifera for management of

Diabetes mellitus is thus found to be effective.

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