Hedychium coronarium Rhizomes: Promising Antidiabetic and Natural Inhibitor of α-Amylase and α-Glucosidase

A comprehensive in-vitro/in-vivo screening toolbox for the elucidation of glucose homeostasis modulating properties of plant extracts (from roots) and its bioactives

Plant extracts are increasingly recognized for their potential in modulating (postprandial) blood glucose levels. In this context, root extracts are of particular interest due to their high concentrations and often unique spectrum of plant bioactives. To identify new plant species with potential glucose-lowering activity, simple and robust methodologies are often required. For this narrative review, literature was sourced from scientific databases (primarily PubMed) in the period from June 2022 to January 2024. The regulatory targets of glucose homeostasis that could be modulated by bioactive plant compounds were used as search terms, either alone or in combination with the keyword "root extract". As a result, we present a comprehensive methodological toolbox for studying the glucose homeostasis modulating properties of plant extracts and its constituents. The described assays encompass in-vitro investigations involving enzyme inhibition (α-amylase, α-glucosidase, dipeptidyl peptidase 4), assessment of sodium-dependent glucose transporter 1 activity, and evaluation of glucose transporter 4 translocation. Furthermore, we describe a patch-clamp technique to assess the impact of extracts on KATP channels. While validating in-vitro findings in living organisms is imperative, we introduce two screenable in-vivo models (the hen's egg test and Drosophila melanogaster). Given that evaluation of the bioactivity of plant extracts in rodents and humans represents the current gold standard, we include approaches addressing this aspect. In summary, this review offers a systematic guide for screening plant extracts regarding their influence on key regulatory elements of glucose homeostasis, culminating in the assessment of their potential efficacy in-vivo. Moreover, application of the presented toolbox might contribute to further close the knowledge gap on the precise mechanisms of action of plant-derived compounds.

Phytochemicals of Cocculus hirsutus deciphered SARS-CoV-2 inhibition by targeting main proteases in molecular docking, simulation, and pharmacological analyses

The COVID-19 pandemic is spreading rapidly due to the outbreak of novel coronavirus SARS-CoV-2 across the globe. Anti-COVID-19 drugs are urgently required in this situation. In this regard, the discovery of promising new anti-COVID-19 moieties is expected from traditional medicine. The study is aimed to discover phytochemicals of Cocculus hirsutus having anti-COVID-19 activity via inhibiting main proteases of SARS-CoV-2. Main proteases (Mpro) of SARS-CoV-2 serve as a protuberant target for anti-COVID-19 drug discovery because it is a key enzyme of coronaviruses and has a pivotal role in mediating viral replication and transcription that makes it an attractive drug target. Recent studies indicated the utility of C. hirsutus in the treatment of viral disorders like Dengue. Phytochemicals from C. hirsutus were docked against SARS-CoV-2 main proteases (6LU7, 5R7Y, 5R7Z, 5R80, 5R81, 5R82) using the PyRx virtual screen tool and discovery studio visualizer. Further, molecular dynamics simulations were performed (for 100 ns) to see conformational stability for all complexes. Pharmacokinetic properties and drug-likeness prediction of selected C. hirsutus phytoconstituents were also performed. Betulin, coclaurine, and quinic acid of C. hirsutus were found promising with significant binding affinity to SARS-CoV-2 Mpro in comparison to control. They have shown stable interactions with the amino acid residues present on the active site of most of the SARS-CoV-2 Mpro and were found as promising anti-COVID-19 candidates. These compounds could be potential leads for the development of target-specific anti-COVID-19 therapeutics while ethnomedicinal uses of this herb could further needed for its detailed antiviral therapeutic exploration.Communicated by Ramaswamy H. Sarma.

New Insights into the Latest Advancement in α-Amylase Inhibitors of Plant Origin with Anti-Diabetic Effects

The rising predominance of type 2 diabetes, combined with the poor medical effects seen with commercially available anti-diabetic medications, has motivated the development of innovative treatment approaches for regulating postprandial glucose levels. Natural carbohydrate digestion enzyme inhibitors might be a viable option for blocking dietary carbohydrate absorption with fewer side effects than manufactured medicines. Alpha-amylase is a metalloenzyme that facilitates digestion by breaking down polysaccharides into smaller molecules such as maltose and maltotriose. It also contributes to elevated blood glucose levels and postprandial hyperglycemia. As a result, scientists are being urged to target α-amylase and create inhibitors that can slow down the release of glucose from carbohydrate chains and prolong its absorption, thereby resulting in lower postprandial plasma glucose levels. Natural α-amylase inhibitors derived from plants have gained popularity as safe and cost-effective alternatives. The bioactive components responsible for the inhibitory actions of various plant extracts have been identified through phytochemical research, paving the way for further development and application. The majority of the findings, however, are based on in vitro investigations. Only a few animal experiments and very few human investigations have confirmed these findings. Despite some promising results, additional investigation is needed to develop feasible anti-diabetic drugs based on plant-derived pancreatic α-amylase inhibitors. This review summarizes the most recent findings from research on plant-derived pancreatic α-amylase inhibitors, including plant extracts and plant-derived bioactive compounds. Furthermore, it offers insights into the structural aspects of the crucial therapeutic target, α-amylases, in addition to their interactions with inhibitors.

A Comprehensive Review on Pharmacologically Active Phyto-Constituents from Hedychium species

In this review, we describe and discuss the phytoconstituents present in Hedychium species and emphasize their potential as drug candidates. Though they are widely validated in vitro and in vivo models, to date, no efforts have been made to compile in a single review all the pharmacologically active phytoconstituents from Hedychium species, and their pharmacological and toxicity profile. In this study, we present a reinvestigation of the chemical constituents present in Hedychium species obtained from the essential oil and solvent extraction of the flowers, leaves and rhizomes under consideration. Key databases such as PubMed, Science Direct, Scopus, and Google Scholar amongst others were probed for a systematic search using keywords to retrieve relevant publications on this plant. An exhaustive electronic survey of the related literature on Hedychium species resulted in around 200 articles. Articles published between the years 1975-2021 were included. The studies conducted on either crude extracts, solvent fractions or isolated pure compounds from Hedychium species reported with a varied range of biological effects such as anti-inflammatory, analgesic, antidiabetic, potentially anti-asthmatic, and cytotoxic, among other related activities of the chemical constituents present in its essential oil and solvent extract deployed in this review. Traditional and herbal medication around the world that uses different parts of Hedychium species were considered for anti-inflammatory, skincare, analgesic, anti-asthmatic, anti-diabetic, antidotal uses, among others. These uses support the idea that chemical constituents obtained from solvent extraction may also exert the same action individually or in a synergistic manner. The review concluded that there is scope for computation and biological study to find out possible new targets for strengthening the potency and selectivity of the relevant compounds, and to find a commercial method for extraction of active pharmaceutical ingredients.

Identification of the effective α-amylase inhibitors from Dalbergia odorifera: Virtual screening, spectroscopy, molecular docking, and molecular dynamic simulation

Inhibiting the activity of α-amylase has been considered as one efficient way to prevent and treat type 2 diabetes recently. Dalbergia odorifera, a kind of Leguminosae plant, has a positive therapeutic effect on type 2 diabetes, possibly contributing by some constituents that can inhibit the activity of α-amylase. In this study, we found that eriodictyol was one potential constituent through virtual screening. The interaction mode between eriodictyol and α-amylase was elucidated by molecular docking, multi-spectroscopic analysis, and molecular dynamic simulation. The results revealed that eriodictyol quenched the intrinsic fluorescence of α-amylase, and the quenching mode was static quenching. Eriodictyol could spontaneously interact with α-amylase, mostly stabilized and influenced by the hydrophobic interaction, while the binding sites (n) was 1.13 ± 0.07 and binding constant (K_b) was (1.43 ± 0.14) × 10⁵ at 310 K, respectively. In addition, FT-IR and CD had been applied to identify that eriodictyol can trigger the conformational change of α-amylase. Taken together, the results provided some experimental data for developing new α-amylase inhibitors from Dalbergia odorifera, which may further prevent and treat diabetes and diabetes complications.

Phytochemical Profiling in Conjunction with In Vitro and In Silico Studies to Identify Human α-Amylase Inhibitors in Leucaena leucocephala (Lam.) De Wit for the Treatment of Diabetes Mellitus

Bioactive constituents from natural sources are of great interest as alternatives to synthetic compounds for the treatment of various diseases, including diabetes mellitus. In the present study, phytochemicals present in Leucaena leucocephala (Lam.) De Wit leaves were identified by gas chromatography-mass spectrometry and further examined by qualitative and quantitative methods. α-Amylase enzyme activity assays were performed and revealed that L. leucocephala (Lam.) De Wit leaf extract inhibited enzyme activity in a dose-dependent manner, with efficacy similar to that of the standard α-amylase inhibitor acarbose. To determine which phytochemicals were involved in α-amylase enzyme inhibition, in silico virtual screening of the absorption, distribution, metabolism, excretion, and toxicity properties was performed and pharmacophore dynamics were assessed. We identified hexadecenoic acid and oleic acid ((Z)-octadec-9-enoic acid) as α-amylase inhibitors. The binding stability of α-amylase to those two fatty acids was confirmed in silico by molecular docking and a molecular dynamics simulation performed for 100 ns. Together, our findings indicate that L. leucocephala (Lam.) De Wit-derived hexadecanoic acid and oleic acid are natural product-based antidiabetic compounds that can potentially be used to manage diabetes mellitus.

Swietenine extracted from Swietenia relieves myocardial hypertrophy induced by isoprenaline in mice

As a traditional plant medicine in tropical areas, Swietenia macrophylla seeds are usually applied for some chronic diseases, including hypertension, diabetes, and so on. Few studies have been carried out to identify the effective elements in seed extract and their indications. In this study, we first investigated the functions of the swietenine, an extract from S. macrophylla seeds, using a model of myocardial hypertrophy induced by isoprenaline (ISO). At cellular level, H9c2 cell hypertrophy was also established through the treatment with ISO. The cardiac pathological remodeling was evaluated by echocardiography and histological analysis. Western blot and RT-qPCR were used to detect the expression of possible hypertrophy-promoting genes. Here, our results indicated that swietenine remarkably attenuated ISO-induced myocardial hypertrophy in vivo and in vitro. Moreover, Akt phosphorylation, ANP and BNP mRNA expression were efficiently decreased. Based on these findings, we concluded that swietenine might be a promising anti-hypertrophic agent against cardiac hypertrophy.