Yonsei Med J.  2012 Jan;53(1):138-144. 10.3349/ymj.2012.53.1.138.

Preventive Effects of Green Tea (Camellia Sinensis var. Assamica) on Diabetic Nephropathy

• Kang MY
• Park YH
• Kim BS
• Seo SY
• Jeong BC
• Kim JI
• Kim HH

• KMID: 1779698
• DOI: http://doi.org/10.3349/ymj.2012.53.1.138

Abstract

PURPOSE
This study aimed to evaluate the preventive effects of Camellia sinensis var. assamica (CSVA) on diabetic nephropathy in in vitro and in vivo models.
MATERIALS AND METHODS
MDCK cells were incubated with 1 mM of oxalate with or without different concentrations of CSVA, then MTT and malondialdehyde (MDA) assays were performed to investigate the preventive effects of CSVA on oxalate-induced cytotoxicity and oxidative stress. Thirty male db/db mice were divided into three groups. Group 1 were fed AIN-93G ad libitum; group 2 were fed AIN-93G mixed with 10% fermented CSVA ad libitum; group 3 were fed AIN-93G mixed with 10% non-fermented CSVA ad libitum. The mice were sacrificed 14 weeks later, and the serum glucose level, 24-hour urine chemistry, and morphological changes in the kidneys were examined.
RESULTS
As CSVA concentrations increased, viable MDCK cells increased in concentration. MDA production decreased over time in the CSVA treated group. The creatinine clearance of group 3 was lower than those of groups 1 and 2. The amount of urine microalbumin and protein in group 1 were higher than those in groups 2 and 3. Also, more glomerulus basement membrane foot processes were preserved in groups 2 and 3.
CONCLUSION
In conclusion, CSVA has beneficial preventive tendencies towards diabetic nephropathy in both in vitro and in vivo models.

Keyword

Camellia sinensis var. assamica; diabetic nephropathy; prevention

MeSH Terms

Animals
*Camellia sinensis/chemistry
Cell Line
Cell Survival/drug effects
Diabetes Mellitus, Type 2/complications
Diabetic Nephropathies/*drug therapy/*prevention & control
Disease Models, Animal
Dogs
Kidney/cytology/*drug effects
Male
Mice
Mice, Mutant Strains
Plant Extracts/*pharmacology
*Tea/chemistry

Figure

• 

  Fig. 1 MDCK cell viability on the concentration of CSVA following exposure to sodium oxalate (*p<0.05). MDCK, Madin-Darby canine kidney; CSVA, Camellia sinensis var. assamica.

• 

  Fig. 2 MDA levels following exposure to sodium oxalate and CSVA according to time (*p<0.05 and **p<0.01 ). MDA, malondialdehyde; CSVA, Camellia sinensis var. assamica.

• 

  Fig. 3 The mean kidney weights of the db/db mouse (*p<0.05 and **p<0.01 relative control).

• 

  Fig. 4 Electron microscopy (EM) of GBM (glomerulus basement membrane): (A) Group 1 is the control group. (B) Group 2 is the fermented Camellia sinensis var. assamica (CSVA)-treated group. (C) Group 3 is the non-fermented CSVA-treated group. The black arrows show the GBM foot process.

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