Highest Alpha-glucosidase Inhibitory Activity Research Articles

Kigelia africana fruit fractions inhibit in vitro alpha-glucosidase activity: a potential natural alpha-glucosidase inhibitor

BackgroundDiabetes affects 75% of people in low-income countries, where conventional drugs like metformin are available, but newer drugs like alpha-glucosidase inhibitors are not accessible to most Southern African patients.AimTo evaluate the α-glucosidase and α-amylase inhibitory activities of fractionated aqueous extracts of Kigelia africana fruit (KAFE) and their phytochemical fingerprints using gas chromatography-mass spectrometry (GC–MS).Materials and methodsWe studied K. africana fruit fractions' inhibitory effects on alpha-glucosidase and alpha-amylase using bioassay-guided fractionation, and analyzed their phytochemical profiles with GC–MS.Key findingsBoth the aqueous extract and ethyl acetate fraction of the aqueous extract exhibited a low dose-dependent inhibition of alpha-amylase activity (p < 0.0001). At a concentration of 500 μg/mL, the aqueous extract caused an alpha-glucosidase inhibition of 64.10 ± 2.7%, with an estimated IC50 of 193.7 μg/mL, while the ethyl acetate fraction had an inhibition of 89.82 ± 0.8% and an estimated IC50 of 10.41 μg/mL. The subfraction G, which had the highest alpha-glucosidase inhibitory activity at 85.10 ± 0.7%, had significantly lower activity than the ethyl acetate fraction. The most bioactive fraction was found to contain 11"(2-cyclopenten-1-yl) undecanoic acid, ( +)- and cyclopentane undecanoic acid as well as the indole alkaloids Akuammilan-17-ol-10-methoxy, N-nitroso-2-methyl-oxazolidine and epoxide Oxirane2.2″ -(1.4-butanediyl) bis-.ConclusionThe K. africana fruit fraction demonstrated significant alpha-glucosidase inhibitory activity, while its alpha-amylase inhibitory activity was limited. This study suggests a potential natural alpha-glucosidase inhibitor and phytocompounds that could serve as leads for developing antidiabetic agents.

Anti-oxidative, anti-hyperglycemic and anti-obesity properties of selected edible leafy plants of Sri Lanka

Five selected edible leafy plants of Sri Lanka were studied in vitro to assess their anti-oxidative, anti-hyperglycemic and anti-obesity properties. Powdered samples of the leafy plants, namely Le-kola pala (LE), Kora kaha (KK), Koppa (KO), Stevia (ST) and Yaki naran (YK) were extracted with hexane, ethyl acetate (EtOAc) and methanol (MeOH) sequentially. The extracts were evaluated for total phenolic content, antioxidant potential and in vitro alpha amylase, alpha-glucosidase and lipase inhibitory activities using relevant assays. The highest alpha-glucosidase inhibitory activity was displayed by YK followed by KO. The highest alpha-amylase inhibitory activity was displayed by LE followed by YK. Among all plant extracts, only LE showed a moderate lipase inhibitory activity. These extracts displayed good antioxidant potential, which correlated well with the enzyme inhibitory activities. This study concluded that the extracts of selected edible leafy plants are a potent source of bioactive compounds that claim various pharmacological properties and can be used as safer alternative remedy for managing diabetes.

Antioxidant and alpha-glucosidase inhibitory activities of Euchresta horsfieldii

Abstract. Prihantini AI, Krisnawati, Setyayudi A. 2019. Antioxidant and alpha-glucosidase inhibitory activities of Euchresta horsfieldii. Biofarmasi J Nat Prod Biochem 17: 61-64. Euchresta horsfieldii, known as pranajiwa, is a medicinal plant that is widely grown in Bali and West Nusa Tenggara, Indonesia. Its seeds or fruits are commonly used for body freshness and stamina. The present study aimed to investigate the biological activities of leaves, root, stem, fruits, seeds of the E. horsfieldii. Antioxidant, alpha-glucosidase inhibitory activities and total phenolic compound were evaluated from methanolic extracts of all parts of E. horsfieldii. The result showed that leaf extract of E. horsfieldii exhibited the highest antioxidant activity with IC50 215.11±08.06 µg/mL. Meanwhile, the root extract had the highest alpha-glucosidase inhibitory activity and total phenolic compound with IC50 29.76±13.17 µg/mL and 763±0.01 mg GAE/100mg dry extract, respectively. In conclusion, the study suggested that E. horsfieldii is potential as natural source of antioxidant and alpha-glucosidase inhibitor agents.

Type 2 Diabetes Relevant Bioactive Potential of Freshly Harvested and Long-Term Stored Pears Usingin vitroAssay Models

ABSTRACT Fresh pear consumption could provide health benefits by reducing the risk of chronic diseases such as hyperglycemia linked to type 2 diabetes. This in vitro study investigated the phenolic-linked antihyperglycemia bioactive factors in aqueous and ethanolic extracts of peel and pulp from eight different freshly harvested and long-term stored pear varieties. Total soluble phenolics, 2,2-diphenyl-1-picrylhydrazyl radical scavenging-based antioxidant activity and associated in vitro alpha-glucosidase, alpha-amylase and angiotensin I-converting inhibitory activities were analyzed. Peel extracts had higher total soluble phenolic content and related antioxidant capacity than pulp extracts. Comice variety had the highest total phenolic contents with positive correlation to total antioxidant activity. Aqueous pulp extracts had high alpha-amylase inhibitory activities with no correlation to phenolic content. However, the peel ethanolic extracts had the highest alpha-glucosidase inhibitory activity with positive correlation to total phenolics. This research provides the biochemical rationale for further clinical studies to include pear as part of healthy diet. PRACTICAL APPLICATIONS Using in vitro structure-function relevant bioassays to screen a range of fruits and vegetables helps to develop biochemical rationale to target and strategize the increased use of these fresh fruits and vegetables for better health and wellness. Pears, because of their phenolic bioactives, have potential to be included as a part of a comprehensive diet for managing early stages of hyperglycemia linked to type 2 diabetes. This study provides foundation for screening of pears for improving dietary strategies for managing this chronic disease and can be the biochemical rationale for further clinical studies.

Functionality of Bioactive Compounds in Brazilian Strawberry (Fragaria × ananassa Duch.) Cultivars: Evaluation of Hyperglycemia and Hypertension Potential Using in Vitro Models

Fruits of seven fully ripened strawberry cultivars grown in Brazil (Dover, Camp Dover, Camarosa, Sweet Charlie, Toyonoka, Oso Grande, and Piedade) were evaluated for total phenolics, antioxidant activity based on DPPH radical scavenging assay, and functionality such as inhibition of alpha-amylase, alpha-glucosidase, and angiotensin I-converting enzyme (ACE) relevant for potentially managing hyperglycemia and hypertension. The total phenolics content ranged from 966 to 1571 microg of gallic acid/g of fruit fresh weight for Toyonoka and Dover, respectively. No correlation was found between total phenolics and antioxidant activity. The major phenolic compounds in aqueous extracts of strawberries were ellagic acid, quercetin, and chlorogenic acid. Strawberries had high alpha-glucosidase inhibitory activity. However, alpha-amylase inhibitory activity was very low in all cultivars. This suggested that strawberries could be considered as a potential dietary source with anti-hyperglycemic potential. The evaluated cultivars had no significant ACE inhibitory activity, reflecting low anti-hypertensive potential.

Alpha-Glucosidase Inhibitory and Antioxidant Activities of Vietnamese Edible Plants and Their Relationships with Polyphenol Contents

The prevention and treatment of non-communicable diseases by using the beneficial biological effects of polyphenolic plants have attracted increasing interest from nutritional scientists. The a-glucosidase inhibitory and antioxidant activities of aqueous and methanolic extracts from 28 common Vietnamese edible plants, comprising 4 groups (plants used for making drinks, edible wild vegetables, herbs, and dark green vegetables), were investigated in vitro. The polyphenol contents of these extracts were determined by the Folin-Ciocalteu method and calculated as catechin equivalents. The extracts from plants used for making drinks showed the highest activities for both a-glucosidase inhibition and as antioxidants, followed by edible wild vegetables, herbs, and dark green vegetables. Positive relationships among alpha-glucosidase inhibitory activities, antioxidant activities and polyphenol contents of these 28 edible plants were found in both aqueous and methanolic extracts. Four new promising materials that are similar to or better than guava leaf extract, including Syzygium zeylanicum, Cleistocalyx operculatus, Horsfieldia amygdalina and Careya arborea demonstrated high alpha-glucosidase inhibitory activity (93, 76, 68 and 67%, respectively) at the final concentration of 0.8 mg lyophilized material/mL solution and antioxidant activity (85, 87, 78 and 80%, respectively) at the final concentration of 30 pg lyophilized material/mL solution. These four edible plants contained significantly high polyphenol contents (equivalent to 251.7, 146.6, 136.6 and 168.6 mg of catechin/g dry weight, respectively). Thus, these four materials might be possible new sources of a-glucosidase inhibition and antioxidants suitable for use as functional foods in the future.