Biological Effects of the Muscadine
Biological Effects of the Muscadine
1. Anti-inflammatory Properties of Muscadine Grapes
2. Lowering of Blood Glucose Concentrations in Diabetics by Muscadines
3. Effect of Muscadines on Enzymes Involved in Cancer
Anti-Inflammatory Properties of Muscadine Grapes
A. Effect on the Release of Cytokines Superoxide Free Radicals
Researchers at the University of Georgia have evaluated the anti-inflammatory activity of muscadine skins (Ison cultivar) which were dried, pulverized and extracted (10% w/v) with 50% ethanol (Greenspan and coworkers, 2004). These extracts were tested in two different assays; (1) the production of superoxide free radicals in phorbol myristate acetate-activated neutrophils, and (2) the release of cytokines by LPS-activated peripheral blood mononuclear cells. In both systems, the release of superoxide and cytokines mediate the inflammatory process.
Neutrophils were purified from human blood and incubated with muscadine skin extract for 1 hr at 37 C. The cells were then stimulated with phorbol myrstate acetate (100 ng/ml) and incubated for one hour and the production of superoxide radicals was measured. As illustrated in Figure 1, a concentration dependent inhibition of superoxide production was observed. A 1:25 final dilution of the Ison skin extract produced a 94% inhibition in the release of superoxide radicals, while a 1:100 dilution of the extract resulted in an approximately 65% inhibition. For comparison, aspirin (not shown) at a concentration of 100 �g/ml, inhibited superoxide production by approximately 70%.
The effect of the Ison skin extract on the release of cytokines by activated peripheral blood mononuclear cells was also investigated. Human peripheral blood mononuclear cells were cultured in a microtiter plate in RPMI containing 1 ug/ml Escherichia coli O111:B4 lipopolysaccharide and various concentrations of the muscadine skin extract.. After 24 hours, the culture supernatants assayed for the content of IL-1 and TNF-alpha. As illustrated in Figures 2a and 2b, the muscadine skin extract produced a concentration dependent inhibition in the release of the cytokines. A 1:200 dilution of the muscadine skin extract inhibited the release of TNF-alpha by approximately 15% while a 1:50 dilution produced nearly 90% reduction. The muscadine skin extract was even more potent in its effect on IL-1 release. A 1:400 dilution inhibited IL-1 release by approximately 50% and a 1:200 dilution inhibited the release of IL-1 by 93%.
B. Muscadine Induced Suppression of Carrageenan-induced Paw Edema
As a follow-up to the in vitro cellular data, in vivo experiments were performed to determine the anti-inflammatory activity of a whole product (non-alcoholic extracted) skin powder. Male Sprague-Dawley rats (150-175 g) were fed either normal rat chow or rat chow supplemented with 5% muscadine skin powder for two weeks. On day 15, the rats were injected with 0.5 mg of carrageenan into the subplantar region of the left hind paw while the contralateral hind paw received saline. Hind paw volumes (edema) were measured plethysmographically by displacement of mercury prior to and at 3 hr post-administration of carrageenan. Swelling was determined by subtracting the volume of the right hind paw from that of the left. Indomethacin and other non-steroidal anti-inflammatory drugs have been shown to suppress carrageenan induced edema. As illustrated in Figure 3, rats with muscadine skin powder in the diet had significantly less paw edema than controls. These results demonstrate that powdered whole muscadine skins have marked anti-inflammatory activity.
Effects on Hepatic Gene Expression
Dietary muscadine skin powder profoundly altered hepatic gene expression (Hartle and coworkers, 2004). C57Bl6 male mice were fed normal chow or chow containing 5% muscadine skin powder for two weeks and then sacrificed. The expression of 10,000 genes was determined and only those genes that had a difference between controls and the muscadine fed treatment of at least 2.5 fold were deemed significant. We found that 202 genes were significantly increased by more than 2.5 fold at a significance level of p = 0.05. The same experiment identified 108 genes that were down-regulated by more than 2.5 fold, i.e. less than 40% of controls; thus, the number of up-regulated genes exceeded the number of down-regulated genes by more than 2-fold. Among the genes that were significantly down-regulated in livers of mice fed muscadine skin powder for two weeks were genes involved in the immune cascade. Research is now being performed to specifically identify those genes that are most sensitive to the presence of muscadines in the diet.
Lowering of Blood Glucose Concentrations in Diabetics by Muscadines
Banini and coworkers (2004) recently adminstered muscadine juice or muscadine wine to Type II diabetics for a one month period. They found that both muscadine juice and wine produced a significant lowering in blood glucose concentrations. Muscadine wine, but not muscadine juice also produced a lowering in serum fibrinogen concentrations, an essential protein in the blood clotting cascade. These results suggest that muscadine ingestion can produce a lowering in blood glucose levels that may be beneficial in individuals with Type II diabetes.
Effect of Muscadines on Enzymes Involved in Cancer
The enzymes class called metalloproteinases are involved in the spread of cancer in the body (metastasis). Water extracts of muscadine grapes have been shown to inhibit the activity of both metalloproteinase 2 and 9. This finding suggest that muscadine grapes, by altering the activity of these enzymes, can affect cancer metastasis (13)
1. Lee J.H. and Talcott S.T. J. Agric. Food Chem., 52, 361-366, 2004
2. Heinonen, I.M., Meyer, A.S. and Frankel, E.N. J. Agric. Food Chem., 46, 4107-4112, 1998.
3. Abuja, P.M., Murkovic, M., and Pfannhauser, W. J. Agric. Food Chem., 46, 4091- 4096, 1998.
4. Frankel, E.N., Bosanek, C.A., Meyer, A.S., Silliman, K., and Kirk, L.L. J. Agric. Food Chem., 46, 834-838, 1998.
5. Ghiselli, A., Nardini, M., Baldi, A., and Scaccini, C. J. Agric. Food Chem., 46, 361-367, 1998.
6. Markakis, P. 1982.In Anthocyanins as Food Colors. Markakis, P., ed. Academic Press, Inc. New York, New York, pp. 163-180.
7. Patrana-Bonilla E, Akoh C.C., Sellappan S and Krewer G. J. Agric. Food Chem. 51, 5497-5503, 2003.
8. Yilmaz, Y, and Toledo, R.T. J. Agric. Food Chem., 52:255-260, 2004.
9. Talcott, S. T. and Lee, J.H. J. Agric. Food Chem. 50, 3186-3192, 2002.
10. Greenspan P., Bauer, J.D., Pollock S.H., Hargrove J.L. and Hartle D.K. FASEB J, A99, 2004
11. Hartle D. K., Dean R.G, Hargrove J.L. and Greenspan P. FASEB J. A505, 2004
12. Banini A, Boyd LC, Allen JC, Allen HG and Sauls DL. FASEB J. A124, 2004
13. Tate P., God J., Bibb R., Lu Q. and Larcom LL. Cancer Lett: 212:153-158, 2004
Antiinflammatory properties of the muscadine grape (Vitis rotundifolia).
Greenspan P, Bauer JD, Pollock SH, Gangemi JD, Mayer EP, Ghaffar A, Hargrove JL, Hartle DK.
Nutraceutical Research Laboratories, University of Georgia, Athens, Georgia 30602, USA. [email protected]
The muscadine grape possesses one of the highest antioxidant levels among fruits; yet, the effect of this fruit on mammalian metabolic systems has not received significant attention. To examine the antiinflammatory properties of the muscadine, grape skins were dried, pulverized, and extracted (10% w/v) with 50% ethanol. The extract was then tested in two different assays: the release of superoxide in phorbol myristate acetate-activated neutrophils and the release of cytokines [tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-beta), and interleukin-6 (IL-6)] by lipopolysaccharide-activated peripheral blood mononuclear cells. The release of superoxide and cytokines was inhibited by increasing concentrations of the extract. A 1:100 dilution of the extract inhibited superoxide release by approximately 60% while the release of TNF-alpha and IL-1beta was reduced at a dilution of 1:200 by approximately 15 and 90%, respectively (all P < 0.05). The inhibition pattern on the release of IL-6 was similar to that seen with TNF-alpha. In a related in vivo study, rats were fed a diet containing 5% (wt/wt) dried muscadine grape skins for 14 days and then were injected with carrageenan in the foot pad. After 3 h, paw edema was measured and the rats on the grape skin diet had approximately 50% less paw edema than controls (P < 0.05). These results demonstrate that the muscadine grape skin powder possesses significant in vitro and in vivo antiinflammatory properties.
PMID: 16248541 [PubMed - indexed for MEDLINE]
For now we see through a glass, darkly.... 1st Corinthians 13:12