Potential enzyme inhibitory properties of extracts and fractions from fruit latex of Ficus carica-based on inhibition of α-amylase and α-glucosidase

Phytochemical Composition, In Vitro Antimicrobial, Antioxidant, and Enzyme Inhibition Activities, and In Silico Molecular Docking and Dynamics Simulations of Centaurea lycaonica: A Computational and Experimental Approach

Centaurea lycaonica is a local endemic species from the Centaurea L. genus. The Centaurea species has a wide range of usage in treating diseases in folk medicine. There are limited biological activity studies on this species in the literature. This study investigated enzyme inhibition and antimicrobial activity, antioxidant effect, and chemical content of extract and fractions of C. lycaonica. Enzyme inhibition activity was tested by α-amylase, α-glucosidase, and tyrosinase enzyme inhibition methods and antimicrobial activity by the microdilution method. The antioxidant activity was investigated using DPPH^•, ABTS^•+, and FRAP tests. The chemical content was determined by LC-MS/MS. The methanol extract showed the highest activity for α-glucosidase and α-amylase, even surpassing the positive control acarbose, with IC₅₀ values of 56.333 ± 0.986 and 172.800 ± 0.816 μg/mL, respectively. Additionally, the ethyl acetate fraction also exhibited high activity for α-amylase with an IC₅₀ value of 204.067 ± 1.739 μg/mL and tyrosinase with an IC₅₀ value of 213.900 ± 1.553 μg/mL. Moreover, this extract and fraction were found to have the highest total phenolic and flavonoid contents and antioxidant activity. Additionally, LC-MS/MS analyses of active extract and fraction revealed mainly the presence of phenolic compounds and flavonoids. In silico molecular docking and molecular dynamics simulation studies of determining compounds apigenin and myristoleic acid, common in CLM and CLE extracts and active against α-glucosidase and α-amylase, were performed. In conclusion, methanol extract and ethyl acetate fraction showed potential enzyme inhibition and antioxidant activity as a natural agent. Molecular modeling studies corroborate the findings of in vitro activity analyses.

Ficus carica (Linn.) Leaf and Bud Extracts and Their Combination Attenuates Type-1 Diabetes and Its Complications via the Inhibition of Oxidative Stress

The current work was designed to evaluate the antioxidant activity and antidiabetic effect of Ficus carica L. extracts. For that, the leaves and buds of Ficus carica L. were analyzed to determine their polyphenolic and flavonoid contents and antioxidant activity. Diabetes was induced by a single dose of alloxan monohydrate (65 mg/kg body weight), then diabetic rats were treated with a dose of 200 mg/kg body weight of the methanolic extracts of Ficus carica leaves or buds or their combination for 30 days. Throughout the experiment, blood sugar and body weight were measured every 5 and 7 days respectively. At the end of the experiment, serum and urine were collected for analysis of alanine aminotransferase, aspartate aminotransferase, total cholesterol, triglycerides, creatinine, uric acid, urea, proteins, sodium, potassium, and chloride. Pancreas, liver, and kidney were removed to estimate catalase, glutathione peroxidase, and glutathione activities; lipid peroxidation products were also determined. The results obtained revealed that alloxan has induced hyperglycemia, increased liver and renal biomarkers levels, reduced antioxidative enzymes, and induced lipid peroxidation. However, the treatment with Ficus carica leaf and bud extracts, especially their combination, has attenuated all pharmacological perturbations induced by alloxan.

New benzimidazole-oxadiazole derivatives: Synthesis, α-glucosidase, α-amylase activity, and molecular modeling studies as potential antidiabetic agents

Benzimidazole-1,3,4-oxadiazole derivatives (5a-z) were synthesized and characterized with different spectroscopic techniques such as ¹ H NMR, ¹³ C NMR, and HRMS. The synthesized analogs were examined against α-glucosidase and α-amylase enzymes to determine their antidiabetic potential. Compounds 5g and 5q showed the most activity with 35.04 ± 1.28 and 47.60 ± 2.16 µg/mL when compared with the reference drug acarbose (IC₅₀  = 54.63 ± 1.95 µg/mL). Compounds 5g, 5o, 5s, and 5x were screened against the α-amylase enzyme and were found to show excellent potential, with IC₅₀ values ranging from 22.39 ± 1.40 to 32.07 ± 1.55 µg/mL, when compared with the standard acarbose (IC₅₀  = 46.21 ± 1.49 µg/mL). The antioxidant activities of the effective compounds (5o, 5g, 5s, 5x, and 5q) were evaluated by TAS methods. A molecular docking research study was conducted to identify the active site and explain the functions of the active chemicals. To investigate the most likely binding mode of the substances 5g, 5o, 5q, 5s, and 5x, a molecular dynamics simulation was also carried out.

Silviridoside: A New Triterpene Glycoside from Silene viridiflora with Promising Antioxidant and Enzyme Inhibitory Potential

A new triterpene glycoside, silviridoside, was isolated from the aerial parts of Silene viridiflora (Caryophyllaceae) using different chromatographic techniques. The structure of silviridoside was comprehensively elucidated as 3-O-β-D-galacturonopyranosyl-quillaic acid 28-O-β-D-glucopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→3)]-β-D-fucopyranosyl ester by one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry (HR-MS). Silviridoside showed promising antioxidant activity in different antioxidant assays such as 2,2-diphenyl-1-picrylhydrazyl (DPPH) (2.32 mg TE/g), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) (1.24 mg TE/g), cupric-reducing antioxidant capacity (CUPRAC) (9.59 mg TE/g), ferric-reducing antioxidant power (FRAP) (5.13 mg TE/g), phosphomolybdenum (PHD) (0.28 mmol TE/g), and metal-chelating (MCA) (6.62 mg EDTA/g) assays. It exhibited a good inhibitory potential on acetylcholinesterase (AChE) (2.52 mg GALAE/g), butyrylcholinesterase (BChE) (7.16 mg GALAE/g), α-amylase (0.19 mmol ACAE/g), α-glucosidase (1.21 mmol ACAE/g), and tyrosinase (38.83 mg KAE/g). An in silico evaluation of the pharmacodynamic, pharmacokinetic, and toxicity properties of silviridoside showed that the new compound exhibited reasonable pharmacodynamic and pharmacokinetic properties without any mutagenic effect, but slight toxicity. Thus, it could be concluded that silviridoside could act as a promising lead drug for pharmaceutical and nutraceutical developments to combat oxidative stress and various disorders, but a future optimization is necessary.

Evaluation of the Chemical Composition, Antioxidant and Antidiabetic Activity of Rhaponticoides iconiensis Flowers: Effects on Key Enzymes Linked to Type 2 Diabetes In Vitro, In Silico and on Alloxan-Induced Diabetic Rats In Vivo

Diabetes mellitus (DM) is one of the globally worst killer diseases. In this study, the in vitro and in vivo antidiabetic activity and antioxidant capacity were determined and the phytochemical analyses were carried out on flower extract and sub-extracts of Rhaponticoides iconiensis. The in vitro antidiabetic activity was tested with α-amylase and α-glucosidase enzyme inhibition methods and an in vivo OGTT test in healthy and alloxan-induced rats. Although, the antioxidant activity was investigated with DPPH●, ABTS●+ and FRAP tests, the phytochemical composition analysis was carried out by LC-MS/MS. The highest α-glucosidase and α-amylase activity even from positive control acarbose were found in the ethyl acetate sub-extract of R. iconiensis (IC50 = 11.737 ± 0.823 µg/mL and 84.247 ± 0.721 µg/mL, respectively). This sub-extract also was active according to the results of in vivo tests. Moreover, the highest antioxidant activity on DPPH● (IC50 = 0.126 ± 0.002 mg/mL), FRAP (at a concentration of 1 mg/mL equivalent to 3112.052 ± 2.023 mmol Fe2+) and ABTS+● (at a concentration of 0.5 mg/mL equivalent to 0.608 ± 0.005 µM Trolox) tests. In addition, LC-MS/MS analyses of the active sub-extract revealed mainly the presence of patuletin, patuletin 3,7-diglucoside, naringin and 3,4-dicaffeoylquinic acid detected in the active sub-extract. In silico molecular docking and dynamics simulations studies were performed on these compounds with α-amylase and α-glucosidase enzymes for protein-ligand interactions and stability.

Tandem mass spectrometry of aqueous extract from Ficus dubia sap and its cell-based assessments for use as a skin antioxidant

Since 2006, Ficus dubia has been reported as a new Ficus species in Thailand. As per our recent report, the red-brown aqueous extract of F. dubia sap (FDS) has been determined to strongly exhibit in vitro anti-radicals. However, the phytochemicals in the FDS extract related to health-promoting antioxidation have not been explored. Thus, in this study, we aimed to investigate the chemical components of the F. dubia sap extract by liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-MS/QTOF-MS) and its potential use in cosmetics in terms of cellular antioxidation on keratinocytes (HaCaT), phototoxicity, and irritation on 3D skin cell models following standard tests suggested by the Organization for Economic Cooperation and Development (OECD). It was found that the sap extract was composed of quinic acid and caffeoyl derivatives (e.g., syringoylquinic acid, 3-O-caffeoylquinic acid, 4-O-caffeoylquinic acid, and dimeric forms of caffeoylquinic acids). The extract has significantly exhibited antioxidant activity against H2O2-induced oxidative stress in HaCaT cells. The cellular antioxidative effect of the FDS extract was remarkably dependent on the presence of 3- and 4-O-caffeoylquinic acid in the extract. Furthermore, the FDS extract showed negative results on skin phototoxicity and irritation. Overall, the results reveal that the FDS extract could be developed as a new antioxidant candidate for a skin healthcare product.