The effects of ginseng (Panax quinquefolius)treatment on chronic diabetic complications

Subhrojit Sen & Subrata ChakrabartiDept. of Pathology

University of Western Ontario

• Diabetes mellitus is a heterogeneous clinical syndrome in which the central feature is a chronic elevation of the blood glucose concentration.

• It occurs due to deficiency of insulin (absolute) or resistance to insulin (relative).

• 40% diabetics develop long term complications affecting various organs including retina, heart and kidney.

Introduction

Types of diabetes Type I diabetesResults from the body's failure to produce insulin. It is estimated that 5-10% of Americans who are diagnosed with diabetes have type 1 diabetes.

Type II diabetesResults from insulin resistance (a condition in which the body fails to properly use insulin), combined with relative insulin deficiency. Most Americans who are diagnosed with diabetes have type 2 diabetes.

Gestational diabetesOccurring during pregnancy. Gestational diabetes affects about 4% of all pregnant women - about 135,000 cases in the United States each year.

Retinopathy

Chronic diabetic complications

Nephropathy

Diabetic Neuropathy

Diabetic Cardiomyopathy

CHRONIC COMPLICATIONS OF DIABETES

Others

Retinopathy

Progressive Backgroundi) Neovascularization i) increased capillary

permeability ii) closure of retinal

capillariesiii) vascular leakage

retinal edema iv) accumulation of

lipids v) retinal ischemia

Nephropathy:• Microalbuminuria • elevated blood pressure progresses to macroproteinuria • decline in renal function.

Diabetic Neuropathy:• Peripheral • Focal

Diabetic cardiomyopathy:

• microvascular narrowing

• micro aneurysm (increased risk of rupture)

• hypertrophy

• defects in collagen structure

• myocardial fibrosis

• perivascular fibrosis

Signalling pathways involved in diabetic complications

Hyperglycemia

Aldose reductase pathway

Protein kinase C

Oxidative stress

AGE/RAGE

Growth factors (TGF-β, VEGF etc.)

ET

vasoconstrictionPermeability

PKC, MAPK

Blood flow

Growth Factors Extracellular Matrix Protein

Angiogenesis

Khan et al, Current Vascular Pharmacology, 2006, Vol 4, No. 1

Ginseng has been shown to have antioxidant effect. Prevents oxidative lipid peroxidation and kidney damage in rats. Ginsenosides are the active components of ginseng found mainly in the roots. Structurally, ginsenosides are divided into two types: protopanaxadiol ginsenosides (PPDGs) and protopanaxatriol ginsenosides (PPTGS).

North American Ginseng

Objective

The present study will investigate the • effects of ginseng on glucose-induced changes in human vascular endothelial cells (HUVECs) • biochemical, functional and structural changes in heart, kidney and retina of insulin-dependent (IDDM) and noninsulin-dependent (NIDDM) mouse model.

Experiments on HUVECs

HUVECs were incubated with 25 mM glucose for 24 hrs. Aqueous and ethanolic extracts of ginseng were given at conc. of 5 mg/ml.

Glucose-induced i) fibronectin (FN) ii) FN protein level iii) EDB+FNiv) Vascular Endothelial Growth Factor (VEGF) v) endothelin (ET-1) mRNA levels were measured.

Animal models used in the present study

Type 1 diabetes STZ mice

Type 2 diabetes db/db mice

Type 1

STZ induction (IP, 65 mg/kg BW)Type 2 db/db mice

Mice

Control Diabetic

DC

Diabetic+

Ginseng (DT)

(200mg/Kg BW for 2 months

after onset of diabetes

by oral gavage)

Diabetic

db/db

Control

NC

Experimental Design

NC

Experimental parameters Body weight

Heart weight

Biochemical parameters from- blood :

a) Glucose- urine

a) Albumin by ELISAb) Creatinine by ALKALINE PICRATE

METHOD

Preliminary results on HUVEC

NG: 5mM glucose; HG: 25mM High glucose; I = insulin; GA: aqueous extract of ginseng; GE = ethanolicextract of ginseng. * = significantly different from other groups

ALCOHOLIC EXTRACTS APPEARED TO BE MORE EFFECTIVE

FN-mRNA levels in Endothelial cells

0

0.51

1.5

2

Groups

mR

NA/

18s

RN

A

*

EDB+FN mRNA levels in endothelial cells

0

0.5

1

1.5

2

2.5

NG HG NGI HGI NGGA HGGA NGGE HGGE

Groups

mR

NA/

18 s

RN

A

*

0

1

2

NG HG NGI HGI NGGE HGGE NGGA HGGA

Groups

Con

c. o

f fib

rone

ctin

(ng/

ml)

*

**

NG: 5mM glucose; HG: 25mM High glucose; I = insulin; GA: aqueous extract of ginseng; GE = ethanolic extract of ginseng. * = significantly different from other groups, * *= significantly different with HG and HGGA.

ALCOHOLIC EXTRACTS APPEARED TO BE MORE EFFECTIVE

FN protein levels in endothelial cells

ET-1 mRNA levels in endothelial cells

0

1

2

NG HG NGI

HGI

NGGA

HGGA

NGGE

HGGE

Groups

mR

NA

/18

sR

NA

VEGF mRNA levels in endothelial cells

0

1

2

NG HG NGI HGI NGGA HGGA NGGE HGGE

Groupsm

RN

A/1

8s

RN

A

NG: 5mM glucose; HG: 25mM High glucose; I = insulin; GA: aqueous extract of ginseng; GE = ethanolic extract of ginseng. * = significantly different from other groups

ALCOHOLIC EXTRACTS APPEARED TO BE MORE EFFECTIVE

*

*

Preliminary results on diabetic mouse modelGroups Body

wt. (gms)

Heartwt.

(mgm)

Fasting Blood

Glucosemmol/L

Urinary Albumin (μg/ml)

Urinary Creatinine

(mg/ml)

NC 28 5.5 124.1 10.2 8.86 2.7 0.128 0.01 0.225 0.05

DC 24 1.6 121.12 2.5 27.4 5.5* 0.182 0.02* 0.350 0.025*

DT(ginsengtreated)

27.2 1.7 133.96 5.5 15.28 8.5 0.138 0.007 0.235 0.02

db/db 44.4 1.5* - 29.08 2.5* 0.184 0.02 0.312 0.01*

THE ABOVE PARAMETERS WERE MEASURED AFTER 2 MONTHS OF ONSET OF DIABETES IN CASE OF IDDM MODEL. THE PARAMETERS IN db/db MICE

WERE MEASURED AT 12 WEEKS OF AGE (Duration of diabetes 4 weeks).

Conclusion

In HUVECs:Glucose caused upregulation of FN, EDB+FN, VEGF and

ET-1.Treatment with both aqueous and ethanolic extract of

ginseng (5mg/ml) caused diminution of the above parameters.

In STZ mice:Treatment with ethanolic extract of ginseng (200mg/kg BW/day) for 2 months caused significant diminution of fasting blood glucose, urinary albumin and creatinine levels.

In db/db mice:Enhancement of fasting blood glucose, urinary albumin and creatinine levels occurred after 12 weeks of age.

AcknowledgementI sincerely acknowledge the guidance of my supervisor, Dr.

Subrata Chakrabarti and Dr. Ed Lui, Dept. of Physiology & Pharmacology.

I also acknowledge the guidance and help provided by all members of my laboratory.

1) Shali Chen

2) Biao Feng

3) Jane Chiu

4) Kara McArthur

5) Yuexiu Wu

6) Chunyan Wang

7) Biju George