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Antiglycating potential of Zingiber officinalis and delay of diabetic cataract in rats.

Saraswat M, Suryanarayana P, Reddy PY, Patil MA, Balakrishna N, Reddy GB - Mol. Vis. (2010)

Bottom Line: Earlier we have reported that some common dietary agents have antiglycating activity and ginger (Zingiber officinalis) was one of the few prominent agents that effectively prevented AGE formation in vitro.Molecular analyses indicated that feeding of ginger significantly inhibited the formation of various AGE products including carboxymethyl lysine in the eye lens.In addition, ginger also countered hyperglycemia-induced osmotic stress in the lens.

View Article: PubMed Central - PubMed

Affiliation: Biochemistry Division, National Institute of Nutrition, Hyderabad, India.

ABSTRACT

Purpose: Advanced glycation end products (AGE) are associated in the development of several pathophysiologies including diabetic cataract. Earlier we have reported that some common dietary agents have antiglycating activity and ginger (Zingiber officinalis) was one of the few prominent agents that effectively prevented AGE formation in vitro. In this study we investigated the potential of ginger to prevent diabetic cataract in rats.

Methods: Diabetes was induced in Wistar-NIN rats by intraperitoneal injection of streptozotocin (35 mg/kg bodyweight) and the control rats received vehicle alone. While a set of diabetic animals received AIN-93 diet, another set received either 0.5 or 3% ginger in their diet for a period of two months. Cataract progression was monitored by slit-lamp biomicroscope. At the end of two months, the animals were sacrificed to evaluate non-enzymatic glycation and osmotic stress in the eye lens.

Results: Slit-lamp examination revealed that feeding of ginger not only delayed the onset but also the progression of cataract in rats. Molecular analyses indicated that feeding of ginger significantly inhibited the formation of various AGE products including carboxymethyl lysine in the eye lens. In addition, ginger also countered hyperglycemia-induced osmotic stress in the lens.

Conclusions: The results indicated that ginger was effective against the development of diabetic cataract in rats mainly through its antiglycating potential and to a lesser extent by inhibition of the polyol pathway. Thus, ingredients of dietary sources, such as ginger, may be explored for the prevention or delay of diabetic complications.

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Related in: MedlinePlus

Immunodetection of glucose derived AGEs in the soluble portion of lens protein. A: Representative western blot profile of soluble lens protein probed with anti-AGE-BSA antibodies. Lane 1: Molecular weight markers, Lane 2: Group I, Lane 3: Group II, Lane 4: Group III, Lane 5: Group IV. B: Densitometry analysis of AGE-BSA. Intensity of AGE-BSA signals was quantified considering the intensity of lane 2 in upper panel as 100%. Data in lower panel are mean±SEM of three independent experiments and different superscripts denote that data are significantly different among the groups.
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f5: Immunodetection of glucose derived AGEs in the soluble portion of lens protein. A: Representative western blot profile of soluble lens protein probed with anti-AGE-BSA antibodies. Lane 1: Molecular weight markers, Lane 2: Group I, Lane 3: Group II, Lane 4: Group III, Lane 5: Group IV. B: Densitometry analysis of AGE-BSA. Intensity of AGE-BSA signals was quantified considering the intensity of lane 2 in upper panel as 100%. Data in lower panel are mean±SEM of three independent experiments and different superscripts denote that data are significantly different among the groups.

Mentions: A wide variety of structurally diverse sugar-derived AGE have been demonstrated in cataractous lens and the predominant antigenic AGE are argypyrimidine, carboxyethyllysine, carboxymethyllysine [5-8,39-41]. Having shown the effective reduction of HMW aggregates in the soluble fraction of lens upon feeding ginger, we evaluated the immunoreactivity of some of these AGE using antibodies raised against CML-BSA, MGO-BSA, and AGE-BSA in the soluble as well as insoluble portion of lens protein. While immunoreactivity of glucose derived AGE (AGE-BSA) was found in the soluble portion (Figure 5), the presence of MGO-BSA and CML could be detected in the insoluble protein fraction (Figure 6 and Figure 7). Detection of increased AGE in the insoluble fraction of diabetic lenses indicates that formation of AGE on lens proteins led to aggregation and insolubilization of proteins, finally resulting in cataract formation. Feeding of rats with ginger reduced the formation of AGE in both soluble and insoluble protein fraction suggestive of its antiglycating action (Figure 5, Figure 6, and Figure 7). Ginger was also effective against glyco-oxidative damage to the eye lens as feeding of ginger could decrease protein carbonyls which are increased in diabetic lens soluble protein fraction (Figure 8).


Antiglycating potential of Zingiber officinalis and delay of diabetic cataract in rats.

Saraswat M, Suryanarayana P, Reddy PY, Patil MA, Balakrishna N, Reddy GB - Mol. Vis. (2010)

Immunodetection of glucose derived AGEs in the soluble portion of lens protein. A: Representative western blot profile of soluble lens protein probed with anti-AGE-BSA antibodies. Lane 1: Molecular weight markers, Lane 2: Group I, Lane 3: Group II, Lane 4: Group III, Lane 5: Group IV. B: Densitometry analysis of AGE-BSA. Intensity of AGE-BSA signals was quantified considering the intensity of lane 2 in upper panel as 100%. Data in lower panel are mean±SEM of three independent experiments and different superscripts denote that data are significantly different among the groups.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2925903&req=5

f5: Immunodetection of glucose derived AGEs in the soluble portion of lens protein. A: Representative western blot profile of soluble lens protein probed with anti-AGE-BSA antibodies. Lane 1: Molecular weight markers, Lane 2: Group I, Lane 3: Group II, Lane 4: Group III, Lane 5: Group IV. B: Densitometry analysis of AGE-BSA. Intensity of AGE-BSA signals was quantified considering the intensity of lane 2 in upper panel as 100%. Data in lower panel are mean±SEM of three independent experiments and different superscripts denote that data are significantly different among the groups.
Mentions: A wide variety of structurally diverse sugar-derived AGE have been demonstrated in cataractous lens and the predominant antigenic AGE are argypyrimidine, carboxyethyllysine, carboxymethyllysine [5-8,39-41]. Having shown the effective reduction of HMW aggregates in the soluble fraction of lens upon feeding ginger, we evaluated the immunoreactivity of some of these AGE using antibodies raised against CML-BSA, MGO-BSA, and AGE-BSA in the soluble as well as insoluble portion of lens protein. While immunoreactivity of glucose derived AGE (AGE-BSA) was found in the soluble portion (Figure 5), the presence of MGO-BSA and CML could be detected in the insoluble protein fraction (Figure 6 and Figure 7). Detection of increased AGE in the insoluble fraction of diabetic lenses indicates that formation of AGE on lens proteins led to aggregation and insolubilization of proteins, finally resulting in cataract formation. Feeding of rats with ginger reduced the formation of AGE in both soluble and insoluble protein fraction suggestive of its antiglycating action (Figure 5, Figure 6, and Figure 7). Ginger was also effective against glyco-oxidative damage to the eye lens as feeding of ginger could decrease protein carbonyls which are increased in diabetic lens soluble protein fraction (Figure 8).

Bottom Line: Earlier we have reported that some common dietary agents have antiglycating activity and ginger (Zingiber officinalis) was one of the few prominent agents that effectively prevented AGE formation in vitro.Molecular analyses indicated that feeding of ginger significantly inhibited the formation of various AGE products including carboxymethyl lysine in the eye lens.In addition, ginger also countered hyperglycemia-induced osmotic stress in the lens.

View Article: PubMed Central - PubMed

Affiliation: Biochemistry Division, National Institute of Nutrition, Hyderabad, India.

ABSTRACT

Purpose: Advanced glycation end products (AGE) are associated in the development of several pathophysiologies including diabetic cataract. Earlier we have reported that some common dietary agents have antiglycating activity and ginger (Zingiber officinalis) was one of the few prominent agents that effectively prevented AGE formation in vitro. In this study we investigated the potential of ginger to prevent diabetic cataract in rats.

Methods: Diabetes was induced in Wistar-NIN rats by intraperitoneal injection of streptozotocin (35 mg/kg bodyweight) and the control rats received vehicle alone. While a set of diabetic animals received AIN-93 diet, another set received either 0.5 or 3% ginger in their diet for a period of two months. Cataract progression was monitored by slit-lamp biomicroscope. At the end of two months, the animals were sacrificed to evaluate non-enzymatic glycation and osmotic stress in the eye lens.

Results: Slit-lamp examination revealed that feeding of ginger not only delayed the onset but also the progression of cataract in rats. Molecular analyses indicated that feeding of ginger significantly inhibited the formation of various AGE products including carboxymethyl lysine in the eye lens. In addition, ginger also countered hyperglycemia-induced osmotic stress in the lens.

Conclusions: The results indicated that ginger was effective against the development of diabetic cataract in rats mainly through its antiglycating potential and to a lesser extent by inhibition of the polyol pathway. Thus, ingredients of dietary sources, such as ginger, may be explored for the prevention or delay of diabetic complications.

Show MeSH
Related in: MedlinePlus