α-Glucosidase Inhibitory Effect and Antioxidant Activity of the Extracts of Eighteen Plant Traditionally Used in Algeria for Diabetes

Abstract

Background: This paper focuses on one of the most recurrent hypotheses for the antidiabetic effect of medicinal plants by inhibiting the alpha -glucosidase Objective: In the present study aqueous and hydro -alcoholic extracts of eighteen medicinal plants, collected in the town of Laghouat in the steppe region of Algeria, and which are used in the treatment of diabetes, were examined for α-glucosidase inhibition using an in vitro model. Also total phenol content and antioxidant activity of the extracts was investigated. Methods: The extracts were prepared using distilled water and hydro -alcoholic solvent (methanol/water). The amount of total phenolics and flavonoids in the samples was determined with the Folin-Ciocalteu reagent and with aluminum chloride respectively. To identify plants with inhibitory capacities, we have studied the effects of ours extracts on the kinetics catalyzed of α-glucosidase an enzymes belonging to the class of hydrolase responsible for the digestion and we have subjected our extracts to inhibition assay to determine the inhibition percentage for each extract. Finally, we assessed the potential antioxydant of the best inhibitory plants with the DPPH test. Results: The major plants were found to inhibit enzymatic activity of α-glucosidase and the values of the IC50 constants have been determined for the best inhibitory plants common in both extraction methods (Cistus SP, Salvia officinalis and Zygophylum album), with values ranged from 0.38 to 28.95 mg/ml. The evaluation of antioxidant activity of this plants using DPPH test, shows that the phenolic extract of Salvia officinalis exhibit good antioxidant capacity (8.46 μg/ml) comparatively to the antioxidants taken as reference (BHA, Gallic acid, Rutin, Trolox and Vitamin C). Conclusion: This study is the first report on potential inhibition of these plants extracts on the digestive enzyme, α-glucosidase. The obtained results support the traditionally use of a number of the analyzed species in the in the management of diabetes.

In vitro investigation of the antioxidant and antimicrobial effects of hydro-alcoholic and aqueous extracts of Globularia alypum L.

“…This low value could be explained by the fact that the antioxidant activity not only depends on the concentration of the total phenolics content which was present in the extract, but also on the structure and the interaction between the antioxidants. It is probable that the aqueous extract has lost some active ingredients after heat [31]. In conclusion, the results from this study show that the hydroalcoholic extract of G. alypum could thus be considered as a source of potential antioxidants and will promote the reasonable usage of this plant in food technology and processing as well as for medical use.…”

In vitro antioxidant and α‐amylase inhibitory potential of methanolic and lipid fractions fromPistacia atlantica Desf. galls

“…In addition, it was suggested that an increased level of free radical may be one of the triggers for insulin resistance. Their decrease may be a therapeutic target for glycemic control (Khacheba et al, 2014(Khacheba et al, , 2017. The antioxidant activity of methanolic extracts was estimated by three methods different antioxidant tests, that is, DPPH • , FRAP, and ABTS •+ assays, which are commonly used in biological samples.…”