Numerous bioactive compounds and phytochemicals have been reported to be present Annona muricata (Soursop). Some of these chemical compounds have been linked to the ethnomedicinal properties of the plant and its antioxidant properties. The aim of this study was to assess the proximate composition, phytochemical constituents and in vitro antioxidant properties of A. muricata using standard biochemical procedures. The defatted Annona muricata crude methanolic extracts of the different parts of the plant were used for the estimation of proximate composition and phytochemical screening. The crude methanolic extracts of the different parts of the plant were also fractionated using solvent–solvent partitioning. Petroleum ether, chloroform, ethyl acetate, methanol, and methanol‐water (90:10) were the solvents used for the fractionation. The different fractions obtained were then used to perform in vitro antioxidant analyses including, 1, 1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging ability, ferric reducing properties, and hydroxyl radical scavenging ability. The leaf methanolic extract had a higher lipid content, whereas its chloroform fraction demonstrated a better ability to quench DPPH free radical. The root‐bark methanol‐water, leaf methanol, fruit pulp chloroform, and leaf petroleum ether fractions demonstrated potent ferric reducing properties. The leaf and stem‐bark petroleum ether fractions demonstrated better hydroxyl‐free radical scavenging abilities. The leaf and fruit pulp of Annona muricata have a very potent antioxidant ability compared to the other parts of the plant. This can be associated with the rich phytochemicals and other phytoconstituents like phenols, flavonoids, alkaloids, and essential lipids, etc. Significant correlations were observed between the antioxidant status and phytochemicals present. These results thus suggest that some of the reported ethnomedicinal properties of this plant could be due to its antioxidant potentials.

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Background: Annona muricata has been used in folklore in the management of diabetes. A major strategy in decreasing postprandial hyperglycemia in diabetes involves the inhibition of carbohydrate-hydrolyzing enzymes-αamylase and α-glucosidase. Thus, this study evaluated the in vivo and in vitro inhibitory potentials of the different parts (fruit-pulp, leaf, stem-bark and root-bark) of Annona muricata. Methods: A total of 120 Wistar rats were treated with methanol extracts for 28 days after which blood and tissue samples were collected for α-amylase assay. In vitro inhibitory properties of methanol, ethyl acetate and dichloromethane extracts of the various parts of the plant on α-amylase and α-glucosidase activities were performed using standard procedures. The mode and mechanism of interactions between the enzymes and extracts (and isolated acetogenin) were determined using various kinetic interpolations and in silico experiments. Result: The fruit-pulp and root-bark methanolic extracts better-inhibited plasma and tissue amylase in vivo. The in vitro studies revealed that the stem-bark methanolic, fruit-pulp ethyl acetate, and leaf dichloromethane extracts, better inhibited α-amylase activity compared with the standard acarbose. Also, the leaf methanol, fruit-pulp ethyl acetate, and root-bark dichloromethane extract better inhibited α-glucosidase activity. These observations were corroborated with their higher Bmax and Vmax and lower Kd values. All the extracts exhibited an "uncompetitive" type of inhibition pattern. Also, the isolated acetogenin (15-acetyl guanacone) from the fruit-pulp showed a better binding affinity compared to the standard drug, Metformin. Conclusion: Better natural remedy for diabetics can be obtained from Annona muricata with minimal or no adverse side effects.

The glycemic index (GI) and glycemic load (GL) of processed brown cowpea (Vigna unguiculata) were determined. The whole seeds were dehulled, ground into a paste and steamed (“moin‐moin” MM) or fried (“Akara” FB). Proximate analyses were done to determine the quantity containing 50 g available carbohydrate. Forty healthy volunteers were used for this study. The test groups consumed the processed cowpea while 50 g glucose was administered to the control group. The blood glucose response at 0, 30, 60,120 and 180 min was assessed for each individual of the different groups. The GI values for BB, MM and FB were 46.63 ± 9.0, 50.98 ± 5.74 and 53.42 ± 9.50, respectively. The GL values for the test foods were 5.51 ± 1.19, 6.92 ± 2.14 and 4.94 ± 1.88, respectively. The GI and GL values for the test foods did not differ significantly (P > 0.05). However, BB had the lowest GI and GL values. PRACTICAL APPLICATIONS Legumes, particularly cowpeas, are good sources of nutrients (protein, carbohydrate, fiber, vitamins and minerals). Recently, beans have been shown to be low glycemic index (GI) foods. They therefore have positive health benefits which include hypocholesterolemia, mitigation of diabetes and weight control. Cowpeas are processed traditionally in Nigeria, by soaking, dehulling, grinding, frying steaming and boiling to form cooked beans. These methods are often combined by grinding to a paste and fried or steamed to form “Akara” (fried bean cakes) and “moin‐moin” (steamed bean pudding), respectively. These processing methods generally alter the contents and nutritional quality of the seeds when consumed. Diabetic Nigerians often eat these processed legumes because they help reduce hyperglycemic stress while providing satiety effects. The determination of the glycemic indices and glycemic loads of these processed legumes will give useful information as to how best legumes can be processed for consumption by people with diabetes.