Synergistic effect of potential alpha-amylase inhibitors from Egyptian propolis with acarbose using in silico and in vitro combination analysis.

BACKGROUND: Type 2 Diabetes mellitus (DM) is an affliction impacting the quality of life of millions of people worldwide. An approach used in the management of Type 2 DM involves the use of the carbohydrate-hydrolyzing enzyme inhibitor, acarbose. Although acarbose has long been the go-to drug in this key approach, it has become apparent that its side effects negatively impact patient adherence and subsequently, therapeutic outcomes. Similar to acarbose in its mechanism of action, bee propolis, a unique natural adhesive biomass consisting of biologically active metabolites, has been found to have antidiabetic potential through its inhibition of α-amylase. To minimize the need for ultimately novel agents while simultaneously aiming to decrease the side effects of acarbose and enhance its efficacy, combination drug therapy has become a promising pharmacotherapeutic strategy and a focal point of this study. METHODS: Computer-aided molecular docking and molecular dynamics (MD) simulations accompanied by in vitro testing were used to mine novel, pharmacologically active chemical entities from Egyptian propolis to combat Type 2 DM. Glide docking was utilized for a structure-based virtual screening of the largest in-house library of Egyptian propolis metabolites gathered from literature, in addition to GC-MS analysis of the propolis sample under investigation. Thereafter, combination analysis by means of fixed-ratio combinations of acarbose with propolis and the top chosen propolis-derived phytoligand was implemented. RESULTS: Aucubin, identified for the first time in propolis worldwide and kaempferol were the most promising virtual hits. Subsequent in vitro α-amylase inhibitory assay demonstrated the ability of these hits to significantly inhibit the enzyme in a dose-dependent manner with an IC50 of 2.37 ± 0.02 mM and 4.84 ± 0.14 mM, respectively. The binary combination of acarbose with each of propolis and kaempferol displayed maximal synergy at lower effect levels. Molecular docking and MD simulations revealed a cooperative binding mode between kaempferol and acarbose within the active site. CONCLUSION: The suggested strategy seems imperative to ensure a steady supply of new therapeutic entities sourced from Egyptian propolis to regress the development of DM. Further pharmacological in vivo investigations are required to confirm the potent antidiabetic potential of the studied combination.

A Validated Stability-Indicating HPTLC Assay for Determination of 10-Hydroxy-2-Decenoic Acid Content in Royal Jelly Products Using Robust Regression Methods.

A new, simple, stability-indicating high-performance thin-layer chromatography method was developed for the quantification of 10-hydroxy-2-decenoic acid (10-HDA) in some royal jelly products marketed in Egypt. The used solvent system was chloroform:acetic acid (10:1, v/v) and the bands were measured densitometrically at 210 nm. First- and second-derivative treatments of the data were performed. The present study shows a comparison between three statistical regression methods for handling data: parametric, nonparametric and weighted regression (WR) methods. The developed methods were validated as per International Conference on Harmonization guidelines. To validate the stability-indicating power of the developed analytical method, the royal jelly standard was subjected to forced degradation studies including the effect of hydrolysis, oxidation, photolysis and dry heat. It was found that derivative treatment of the chromatographic response data gives improved quantitation and sensitivity of the chromatographic signals. Weighted regression of the response data is found to be advantageous over the use of both parametric and nonparametric regression models. This was shown by a great enhancement in the accuracy and precision in the analysis of 10-HDA in royal jelly products. The % recovery in case of WR was 99.92 ± 0.16, while % recovery in case of nonparametric and parametric regressions were 99.56 ± 0.25 and 98.63 ± 0.65, respectively.

Analysis of astragalosides I, II and IV in some Egyptian Astragalus species and Astragalus dietary supplements using high-performance liquid chromatography/evaporative light scattering detector and non-parametric regression.

INTRODUCTION: GenuTs Astragalus L. is characterised by the presence of cycloartane saponins which have wide biological activities such as antioxidant, immunomodulating' hepatoprotective and anti-inflammatory activities. From these cycloartane saponins are astragalosides I, II and IV which have been regarded as the most important active constituents in Astragalus species. OBJECTIVES: This work describes the quantitative analysis of astragalosides I, II and IV in some Egyptian Astragalus species and Astragalus dietary supplements in a single run by high-performance liquid chromatography/evaporative light scattering detector (HPLC/ELSD) using gradient elution. METHODOLOGY: The method of quantitation adopted in this study is the standard addition method. First and second derivative treatment of the data was performed, and the study presents comparison between two statistical regression methods for handling data; parametric and non-parametric regression methods. RESULTS: Derivative treatment of the chromatographic response data gives improved quantitation of the chromatographic signals. Non-parametric regression of the data using Theil's method is advantageous over the usual least squares method as it assumes that errors could occur in both x- and y-directions and they might not be normally distributed. In addition, it could effectively circumvent any outlier data points. CONCLUSION: Due to the simplicity and the good accuracy and reproducibility of the suggested methods, they could be used for analysis and quality control of Astragalus species and Astragalus dietary supplements.

Hepatoprotective effects of Astragalus kahiricus root extract against ethanol-induced liver apoptosis in rats.

The hepatoprotective activity of the ethanol extract of Astragalus kahiricus (Fabaceae) roots against ethanol-induced liver apoptosis was evaluated and it showed very promising hepatoprotective actions through different mechanisms. The extract counteracted the ethanol-induced liver enzymes leakage and glutathione depletion. In addition, it demonstrated anti-apoptotic effects against caspase-3 activation and DNA fragmentation that were confirmed by liver histopathological examination. Moreover, the phytochemical study of this extract led to the isolation of four cycloartane-type triterpenes identified as astrasieversianin II (1), astramembrannin II (2), astrasieversianin XIV (3), and cycloastragenol (4). The structures of these isolates were established by HRESI-MS and 1D and 2D NMR experiments. The antimicrobial, antimalarial, and cytotoxic activities of the isolates were further evaluated, but none of them showed any activity.

Chemical constituents from Astragalus annularis Forssk. and A. trimestris L., Fabaceae / Constituintes químicos de Astragalus annularis Forssk. and A. trimestris L., Fabaceae

The phytochemical investigation of the aerial parts of Astragalus annularis Forssk. and A. trimestris L., Fabaceae, growing in Egypt, resulted in the isolation of eight compounds, for the first time from these two species. These compounds were identified by chemical methods, NMR spectroscopy, UV spectroscopy as well as MS analysis. The antimicrobial activity of the isolated compounds were tested against Staphylococcus aureus, Esherichia coli and Candida albicans.

A investigação química das partes aéreas de Astragalus annularis Forssk. e A. trimestris L., Fabaceae, do Egito, resultou no isolamento de oito compostos, pela primeira vez nestas duas espécies. Estes compostos foram identificados por métodos químicos, espectroscopia de RMN, espectroscopia UV, bem como análise de EM. A atividade antimicrobiana dos compostos isolados foi testada contra Staphylococcus aureus, Escherichia coli e Candida albicans.

Kahiricosides II-V, cycloartane glycosides from an Egyptian collection of Astragalus kahiricus.

Four cycloartane-type saponins, kahiricosides II-V (1-4), were isolated from the aerial parts of Astragalus kahiricus of Egyptian origin. Their structures were established as 9beta,19-cyclolanost-24E-ene-3beta,6alpha,16beta,27-tetraol-3-O-beta-D-glucopyranoside, 9beta,19-cyclolanost-24E-ene-3beta,6alpha,16beta,27-tetraol-3-O-(2'-O-acetyl)-beta-D-glucopyranoside, 9beta,19-cyclolanost-24E-ene-3beta,6alpha,16beta,27-tetraol-3-O-(6'-O-acetyl)-beta-D-glucopyranoside, and 9beta,19-cyclolanost-24E-ene-3beta,6alpha,16beta,27-tetraol-3-O-beta-D-glucopyranosyl-27-O-beta-D-glucopyranoside based on chemical and spectral evidences. All compounds exhibited very weak cytotoxicity against the A2780 ovarian cancer cell line.

Acetals of three new cycloartane-type saponins from Egyptian collections of Astragalus tomentosus.

Three new cycloartane-type saponin ethyl acetals, deacetyltomentoside I (2), tomentoside III (3), and tomentoside IV (4), were isolated along with the known acetal tomentoside I (1) from the aerial parts of Astragalus tomentosus of Egyptian origin. The saponins from which the acetals are most probably derived are also new compounds. The structures of the acetals were established as 6alpha-hydroxy-23alpha-ethoxy-16beta,23(R)-epoxy-24,25,26,27-tetranor-9,19-cyclolanosta-3-O-beta-d-xyloside (2), 6alpha-acetoxy-23alpha-ethoxy-16beta,23(R)-epoxy-24,25,26,27-tetranor-9,19-cyclolanosta-3-O-[beta-d-(4'-trans-2-butenoyl)]xyloside (3), and 6alpha-acetoxy-23alpha-ethoxy-16beta,23(R)-epoxy-24,25,26,27-tetranor-9,19-cyclolanosta-3-O-[beta-d-glucopyranosyl(1 --> 2)]-beta-d-xyloside (4), by detailed spectroscopic and chemical studies.