Glucose oxidase as a model enzyme for antidiabetic activity evaluation of medicinal plants: <i>In vitro</i> and <i>in silico</i> evidence

Abstract

Diabetes mellitus is a major public health problem in the world. In Africa, more than 80% of patients use plants for their treatment. However, the methods of validation of endogenous knowledge usually used are costly. The alternative method developed in this study aims at creating hyperglycemia &lt;i&gt;in vitro&lt;/i&gt; and exploiting the metabolic pathway involving glucose oxidase for UV-visible spectrophotometric screening of medicinal plants’ antidiabetic activity. The evolution of glucose oxidation as a function of drug concentration is followed by UV-visible spectrophotometry. The formation of the stable complex between the enzyme and the inhibitor is studied using molecular docking. Drugs used (Gliben) and plant extracts exhibited an &lt;i&gt;in vitro&lt;/i&gt; hypoglycemic effect by reducing exponentially, &lt;i&gt;in vitro&lt;/i&gt;, the level of free glucose. The results also showed that &lt;i&gt;L. multiflora&lt;/i&gt; is more active than &lt;i&gt;V. amygdalina&lt;/i&gt; (IC&lt;sub&gt;50&lt;/sub&gt;: 1.36 ± 0.09 mg/mL Vs IC&lt;sub&gt;50&lt;/sub&gt;: 3.00 ± 0.54 mg/mL). Gliben (0.5 mg/mL) and &lt;i&gt;L. multiflora&lt;/i&gt; (2 mg/mL) reduced both the rate of oxidation of glucose by glucose oxidase (catalytic power V&lt;sub&gt;max&lt;/sub&gt;: 0.84 ± 0.11 mg*mL&lt;sup&gt;-1&lt;/sup&gt;*min&lt;sup&gt;-1&lt;/sup&gt; for Gliben and 1.72 ± 0.13 mg*mL&lt;sup&gt;-1&lt;/sup&gt;*min&lt;sup&gt;-1&lt;/sup&gt; for &lt;sup&gt;L. multiflora&lt;/sup&gt;); and the affinity of this enzyme for its substrate-glucose (K&lt;sub&gt;M&lt;/sub&gt;: 15.11 ± 2.72 mg*mL&lt;sup&gt;-1&lt;/sup&gt; for Gliben and 9.17 ± 1.56 mg*mL&lt;sup&gt;-1&lt;/sup&gt; for &lt;i&gt;L. multiflora&lt;/i&gt;) when these results are compared to enzyme catalysis in the absence of inhibitor (V&lt;sub&gt;max&lt;/sub&gt;: 2.86 ± 0.44 mg*mL&lt;sup&gt;-1&lt;/sup&gt;*min-1; K&lt;sub&gt;M&lt;/sub&gt;: 8.07 ± 1.96 mg*mL&lt;sup&gt;-1&lt;/sup&gt;). The binding of GOX (1GAL) to selected phytocompounds derived from &lt;i&gt;L. multiflora&lt;/i&gt; was confirmed by molecular docking. The most stable complexes were obtained for four compounds; &lt;b&gt;8&lt;/b&gt; (-10.1±0.0 Kcal/mol), &lt;b&gt;6&lt;/b&gt; (-9.5±0.1 Kcal/mol), &lt;b&gt;3&lt;/b&gt; (-8.3±0.0 Kcal/mol) and &lt;b&gt;9&lt;/b&gt; (-8.2±0.1 Kcal/mol). Among these, compounds &lt;b&gt;8&lt;/b&gt; and &lt;b&gt;6&lt;/b&gt; formed complexes with the enzyme stabilized by hydrogen bonds, the compound &lt;b&gt;8&lt;/b&gt; forms 5 hydrogen bonds (&lt;b&gt;ASN514&lt;/b&gt;, &lt;b&gt;ASP424&lt;/b&gt;, &lt;b&gt;ARG95&lt;/b&gt;, &lt;b&gt;TYP68&lt;/b&gt;, &lt;b&gt;LEU65&lt;/b&gt;) while compound &lt;b&gt;6&lt;/b&gt; forms 2 hydrogen bonds (&lt;b&gt;ASN514&lt;/b&gt; and &lt;b&gt;SER422&lt;/b&gt;). However, no H-bonding interaction occurs in the complex that involves ligands &lt;b&gt;9&lt;/b&gt; and &lt;b&gt;3&lt;/b&gt; despite their high binding energy (-8.2±0.1 Kcal/mol and -8.3±0.0 Kcal/mol respectively). Glucose oxidase can serve as a marker enzyme for&lt;i&gt; in vitro&lt;/i&gt; antidiabetic activity evaluation of medicinal plants.

Integrating Ethnobotany and Artificial intelligence to validate the potential bioactivity of Two Medicinal Plants Traditionally used in the treatment of influenza in IBI-Village and surrounding areas, Democratic Republic of the Congo

“…The development of these medicinal plants is of great concern to South African countries, as most of the population relies directly on traditional medicine and lacks adequate care, particularly in poor areas. Moreover, for certain diseases that modern medicine does not provide appropriate treatment, traditional recipes are an alternative (Masengo et al, 2022;Tshilanda et al, 2014). In fact, the antiviral activity of medicinal plants that treat respiratory diseases is scientific evidence (Mpiana et al, 2022a(Mpiana et al, , 2022b; K.N.…”

Evaluation of Clove Phytochemicals as Potential Antiviral Drug Candidates Targeting SARS-CoV-2 Main Protease: Computational Docking, Molecular Dynamics Simulation, and Pharmacokinetic Profiling

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