Cucurbita ficifolia, Phaseolus vulgaris, Opuntia streptacantha, Spinacea oleracea, Cucumis sativus, Cuminum cyminum, Brassica oleracea var. botrytis, Allium cepa, Allium sativum, Psidium guajava, Brassica oleracea and Lactuca sativa var. romana

To study the anti-hyperglycemic effect of 12 edible plants

Journal of Ethnopharmacology 1995; 48:25-32

Anti-hyperglycemic effect of some edible plants

R. Roman-Ramos, J.L. Flores-Saenz, F.J. Alarcon-Aguilar

Department of Health Sciences, Division of Biological and Health Sciences, Metropolitan Autonomous University, lztapalapa Campus. Mexico, D.F., Apdo. Postal 55-535, Mexico

The anti-hyperglycemic effect of 12 edible plants was studied on 27 healthy rabbits, submitted weekly to subcutaneous glucose tolerance tests after gastric administration of water, tolbutamide or a traditional preparation of the plant. Tolbutamide, Cucurbita ficifolia, Phaseolus vulgaris, Opuntia streptacantha, Spinacea oleracea, Cucumis sativus and Cuminum cyminum decrease significantly the area under the glucose tolerance curve and the hyperglycemic peak. Brassica oleracea var. botrytis, Allium cepa and Allium sativum only decrease the hyperglycemic peak. The glycemic decreases caused by Psidium guajava, Brassica oleracea and Lactuca sativa var. romana were not significant (p > 0.05). The integration of a menu that includes the edible plants with hypoglycemic activity for the control and prevention of diabetes mellitus may be possible and recommendable.

Effects of long-term low-glycaemic index starchy food on plasma glucose and lipid concentrations and adipose tissue cellularity in normal and diabetic rats

The present study aimed to assess the metabolic consequences of the chronic ingestion of two starches giving different postprandial glycaemic responses in normal and diabetic rats. The two starches chosen were mung-bean (Phaseolus aureus) starch (97% pure starch) and wheat starch presented as ground French toast. First, we studied the characteristics of these two starches. In vitro the alpha-amylase (EC 3.2.1.1) digestibilities of these starches were 40 (SE 3) and 62 (SE 4)% respectively at 30 min, whereas the contents of resistant starch were 77 (SE 4) and 22 (SE 4) g/kg respectively. In vivo the mung-bean starch produced lower postprandial glycaemic responses than the wheat starch (areas under the curve were: 91 (SE 28) and 208 (SE 33) mmol.min/l, P < 0.05) in normal rats (n 8). We then submitted twenty-eight normal and twenty-eight diabetic (neonatal streptozotocin on second day of birth) male Sprague-Dawley rats (6 weeks old) to a diet containing 570 g starch/kg as either mung-bean starch or wheat starch (n 14 rats/group). After 5 weeks on the diets food intakes and body weights were identical in each group. Liver and kidney weights were comparable when expressed as relative weight. The mung-bean-starch diet slightly decreased epididymal fat-pad weight (P < 0.14, ANOVA) and led to a marked decrease in adipocyte volume (P < 0.05). Plasma triacylglycerol and phospholipid concentrations were lower after the mung-bean-starch diet than after the wheat-starch diet in both normal and diabetic rats, whereas free fatty acid concentrations were lower only in normal rats. Similarly, non-fasting plasma glucose concentrations decreased (P < 0.05) in normal rats fed on mung-bean starch but not in diabetic ones (P < 0.14). Insulin levels tended to be lower, but not significantly, after mung-bean-starch feeding than after wheat starch. We conclude that the replacement of 570 g wheat starch/kg diet with mung-bean starch for 5 weeks resulted in (1) lowered non-fasting plasma glucose and free fatty acid levels in normal but not in diabetic rats, (2) a reduction in plasma triacylglycerol concentration and adipocyte volume in both normal and diabetic rats. Thus, the type of starch mixed into the diet may have important metabolic consequences in normal and diabetic rats.

Department of Biochemistry, Faculty of Science, Annamalai University, Annamalainagar, Tamil Nadu, India

Glutathione S-transferases and malondialdehyde in the liver of NOD mice on short-term treatment with plant mixture extract P-9801091

Changes in the concentration of glutathione S-transferases (GSTs) and malondialdehyde (MDA) were assessed in the liver of normal and diabetic NOD mice with and without treatment with the plant extract P-9801091. The plant extract P-9801091 is an antihyperglycaemic preparation containing Myrtilli folium (Vaccinium myrtillus L.), Taraxaci radix (Taraxacum officinale), Cichorii radix (Cichorium intybus L.), Juniperi fructus (Juniperus communis L.), Centaurii herba (Centaurium umbellatum Gilib.), Phaseoli pericarpium (Phaseolus vulgaris L.), Millefoliiherba (Achillea millefolium L.), Mori folium (Morus nigra L.), Valerianae radix (Valeriana of ficinalis L.) and Urticae herba et radix (Urtica dioica L). Hyperglycaemia in diabetes mellitus is responsible for the development of oxidative stress (via glucose auto-oxidation and protein glycation), which is characterized by increased lipid peroxide production (MDA is a lipid peroxidation end product) and/or decreased antioxidative defence (GST in the liver is predominantly an alpha enzyme, which has antioxidative activity). The catalytic concentration of GSTs in the liver was significantly reduced in diabetic NOD mice compared with normal NOD mice (p < 0.01), while the concentration of MDA showed a rising tendency (not significant). The results showed that statistically significant changes in antioxidative defence occurred in the experimental model of short-term diabetes mellitus. A 7-day treatment with P-9801091 plant extract at a dose of 20 mg/kg body mass led to a significant increase in the catalytic concentration of GSTs in the liver of diabetic NOD mice (p < 0.01) and a decrease in MDA concentration (not significant), which could be explained by its antihyperglycaemic effect.