Endocrine Abstracts

Background: Cladodes of the nopal opuntia streptacantha (prickly-pear cactus) have been traditionally used for the treatment of diabetes in Mexico. Limited data from studies in experimental animals and humans with prediabetes or type 2 diabetes (DM2), have shown promising antihyperglycemic effects using plant extracts of the streptacantha and ficus-indica opuntia species. The purpose of this study was to assess the effect of opuntia ficus-indica plant extract ingestion on plasma glucose and insulin levels in healthy subjects as well as in subjects with prediabetes or diabetes.

Methods: A total of 35 subjects were studied, subdivided in two groups: subjects with normal glucose tolerance (Group A) and subjects with either prediabetes (IGT and/or IFG) or DM2 treated with diet and/or metformin (Group B). All subjects underwent a 75 g oral glucose tolerance test (OGTT) and plasma glucose and insulin levels were measured at 0, 30, 60, 90 and 120 min. Up to 4 weeks later, subjects underwent a 2nd 75g OGTT, during which they ingested 1000 mg of Opuntia ficus-indica dry extract (in a capsule form) 30 min prior to glucose ingestion. Glucose and insulin levels between the two OGTTs were compared by longitudinal analysis.

Results: Group A consisted of 13 healthy subjects (31% male, age 41±15 years (mean±standard deviation), BMI 28±5 kg/m², waist circumference 90±15 cm) and Group B of 22 subjects (16 with prediabetes and six with DM2, 55% male, age 54±14 years, BMI 28±4 kg/m²). In both Groups A and B, co-administration of the plant extract prior to the 75g OGTT did not result in significant changes in the area under the curve for glucose or in the glucose and insulin levels at any time point (P=ns). At the end of the OGTT (120′) in Group A, were 106±26 versus 102±24 mg/dl, and 29±19 versus 26±22 μIU/ml, respectively (P>0.05). In group B, glucose and insulin values were: 159±70 versus 150±65 mg/dl, and 56±61 versus 43±30 μIU/ml, respectively (P=ns).

Conclusion: Short-term administration of Opuntia ficus-indica extract in individuals with normal glucose tolerance, prediabetes or diabetes did not affect glucose and insulin levels during OGTT. To further explore a possible antidiabetic effect, larger studies and long-term administration of this plant extract are required.