Moringa oleifera trees grow well in Jamaica and their parts are popularly used locally for various purposes and ailments. Antioxidant activities in Moringa oleifera samples from different parts of the world have different ranges. This study was initiated to determine the antioxidant activity of Moringa oleifera grown in Jamaica. Dried and milled Moringa oleifera leaves were extracted with ethanol/water (4:1) followed by a series of liquid–liquid extractions. The antioxidant capacities of all fractions were tested using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. IC50 values (the amount of antioxidant needed to reduce 50% of DPPH) were then determined and values for the extracts ranged from 177 to 4458 μg/mL. Extracts prepared using polar solvents had significantly higher antioxidant capacities than others and may have clinical applications in any disease characterized by a chronic state of oxidative stress, such as sickle cell anemia. Further work will involve the assessment of these extracts in a sickle cell model of oxidative stress.
1 January 1992 in Journal of the Science of Food and Agriculture
Background: Fruits, vegetables and legumes for their complex carbohydrates, dietary fiber and micronutrients, should form an essential part of every diet. In order to give good dietary advice to diabetic patients, it is necessary to know the glycemic index of foods commonly consumed locally. The objective of this study was to determine the Glycemic Index (GI) and Glycemic Load (GL) of commonly available and consumed Guava (Psidium guajava), Watermelon (Citrullus vulgaris), Gungo (Cajanus cajan), Papaya (Carica papaya) and tomato (Solanum lycopersicum) in Jamaica. Methods: Ten (10) healthy Jamaican subjects (5 males, 5 females) with mean age 30 ± 2 years and mean BMI 25 ± 1 kg/m2 were recruited to the study. Using a non-blind, crossover design trial, the subjects consumed 50 (or 25) grams of available carbohydrate portions of glucose (standard food) and test foods after an overnight fast and their serum glucose levels were determined at 0, 15, 30, 45, 60, 90 and 120 minutes after the consumption of each test food. Glucose was tested on three separate occasions, and the test foods once. The GI value was calculated geometrically by expressing the Incremental Area Under the Blood Glucose Curve (IAUC) for the test foods as a percentage of each subject's average IAUC for the standard food. Results: The results indicated that the IAUC for Watermelon (95 ± 11) was significantly higher (p<0.05) than that of Tomato (37 ± 12), and Gungo (58 ± 13). The differences in IAUC of Watermelon (95 ± 11), Guava (83 ± 27) and Papaya (80 ± 7) were not statistically significant. Similarly, there was no significant difference in GI among the samples studied. Conclusion: Tomato, Gungo, Papaya Watermelon and Guava were shown to have low glycemic index and glycemic load values.