Model Optimization and In Silico Analysis of Potential Dipeptidyl Peptidase IV Antagonists from GC-MS Identified Compounds in Nauclea latifolia Leaf Extracts

Acute and sub-chronic toxicity studies of methanol extract of Trema orientalis (Linn) blume in albino wistar rats

Background

The safety potential of the methanol extract of Trema orientalis (TOM) leaf was evaluated in albino Wistar rats using biochemical, haematological, and histological indices in both acute and sub-chronic toxicity studies.

Methods

The animals were managed following the National Institute of Health (NIH) stipulated protocols for handling laboratory animals. The weight of each animal was recorded upon arrival and monitored throughout the study. The animals were allowed to acclimatize for 14 days, after which they were reweighed and randomly distributed into four groups of three female rats (n=12) for acute toxicity studies. Group A was given distilled water, and Groups B, C, and D were given a single dose of 2000, 4000, and 5000 mg/kg bw TOM extract, respectively. On day 15, each animal was anaesthetized and then euthanized. For the sub-chronic toxicity study, animals were randomly distributed into five groups of eight female rats (n=40). They were dosed daily for 28 days. Group A (Negative control group) was given distilled water. Groups B, C, and D had 200, 400, and 800 mg/kg bw TOM extract and Group E (Vehicle control group) were given 0.25 % of sodium carboxyl methyl cellulose (CMC). Five animals were anaesthetized and then euthanized on day 29, while three animals were kept for recovery evaluation for another two weeks without further administration of the extract. Ten organs were excised from each animal and weighed. The liver and kidney were processed for histopathological studies, while the blood samples were collected for biochemical and haematological assays.

Results

From acute toxicity studies, the LD50 value of TOM extract was estimated to exceed 5000 mg/kg bw via oral passage. From Sub-chronic toxicity studies, biochemical results showed a significant (p < 0.05) reduction in total protein, albumin, globulin, AST, ALP, and ALT in a dose-dependent manner. Histology of the liver and kidney tissues of all the animals except the kidney of the 800 mg/kg group had no visible lesions; this sets the safety dose for TOM at above 400 mg/kg but below 800 mg/kg. Recovery animals had significantly (p < 0.05) increased total protein, total bilirubin, and ALP and decreased albumin and direct bilirubin levels.

Conclusion

This study reports the safety dose of TOM, a reputable medicinal plant extract. This is the first study reporting that the LD50 value of TOM extract exceeds 5000 mg/kg bw via oral passage.

Mango peel extracts and mangiferin chromatographic Fourier-transform infrared correlation with antioxidant, antidiabetic, and advanced glycation end product inhibitory potentials using in silico modeling and in vitro assays

Mangifera indica peels are a rich source of diverse flavonoids and xanthonoids; however, generally these are discarded. Computational studies revealed that mangiferin significantly interacts with amino acid residues of transcriptional regulators 1IK3, 3TOP, and 4f5S. The methanolic extract of Langra variety of mangoes contained the least phenol concentrations (22.6 ± 0.32 mg/gGAE [gallic acid equivalent]) compared to the chloroform (214.8 ± 0.12 mg/gGAE) and ethyl acetate fractions (195.6 ± 0.14 mg/gGAE). Similarly, the methanolic extract of Sindhri variety contained lower phenol concentrations (42.3 ± 0.13 mg/gRUE [relative utilization efficiency]) compared with the chloroform (85.6 ± 0.15 mg/gGAE) and ethyl acetate (76.1 ± 0.32 mg/gGAE) fractions. Langra extract exhibited significant α-glucosidase inhibition (IC50 0.06 mg/mL), whereas the ethyl acetate fraction was highly active (IC50 0.12 mg/mL) in Sindhri variety. Mangiferin exhibited significant inhibition (IC50 0.026 mg/mL). A moderate inhibition of 15-LOX was observed in all samples, whereas mangiferin was least active. In advanced glycation end product inhibition assay, the chloroform fraction of Langra variety exhibited significant inhibition in nonoxidative (IC50 64.4 μg/mL) and oxidative modes (IC50 54.7 μg/mL). It was concluded that both Langra and Sindhri peel extracts and fractions possess significant antidiabetic activities. The results suggest the potential use of peel waste in the management and complications of diabetes.

In silico evaluation of potential breast cancer receptor antagonists from GC-MS and HPLC identified compounds in Pleurotus ostreatus extracts

Introduction: Pharmacotherapeutic targets for breast cancer include the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor (EGFR). Inhibitors of these receptors could be interesting therapeutic candidates for the treatment and management of breast cancer (BC). Aim: This study used GC-MS and HPLC to identify bioactive compounds in Pleurotus ostreatus (P. ostreatus) extracts and applied in silico methods to identify potent EGFR, ER, and PR inhibitors from the compounds as potential drug candidates. Method: GC-MS and HPLC were used to identify bioactive chemicals in P. ostreatus extracts of aqueous (PO-A), methanol (PO-M), ethanol (PO-E), chloroform (PO-C), and n-hexane (PO-H). The ER, PR, and EGFR model optimization and molecular docking of compounds/control inhibitors in the binding pocket were simulated using AutoDock Vina in PyRx. The drug-likeness, pharmacokinetic, and pharmacodynamic features of prospective docking leads were all anticipated. Result: The results indicated the existence of 29 compounds in PO-A, 36 compounds in PO-M and PO-E, 42 compounds in PO-C, and 22 compounds in PO-H extracts. With ER, only o-tolylamino-acetic acid (4-nitro-benzylidene)-hydrazide (-7.5 kcal mol-1) from the ethanolic extract could bind to the receptor. PR and EGFR, on the other hand, identified several compounds with higher binding affinities than the control. Ergotaman-3',6',18-trione (-8.1 kcal mol-1), 5,10-diethoxy-2,3,7,8-tetrahydro-1H,6H-dipyrrolo[1,2-a:1',2'-d]pyrazine (-7.8 kcal mol-1) from the aqueous extract; o-tolylamino-acetic acid (4-nitro-benzylidene)-hydrazide (-8.4 kcal mol-1) from the ethanolic extract had better binding affinity compared to progesterone (-7.7 kcal mol-1). Likewise, ergotaman-3',6',18-trione (-9.7 kcal mol-1) from the aqueous extract and phenol, 2,4-bis(1,1-dimethyl ethyl) (-8.2 kcal mol-1) from the chloroform extract had better binding affinities compared to the control, gefitinib (-7.9 kcal mol-1) with regards to EGFR. None of the PO-H or PO-M extracts outperformed the control for any of the proteins. Phenols and flavonoids such as quercetin, luteolin, rutin, chrysin, apigenin, ellagic acid, and naringenin had better binding affinity to PR and EGFR compared to their control. Conclusion: The identified compounds in the class of phenols and flavonoids were better lead molecules due to their ability to strongly bind to the proteins' receptors. These compounds showed promising drug-like properties; they could be safe and new leads for creating anticancer medicines.

Evaluating Khaya senegalensis for Dipeptidyl Peptidase-IV Inhibition Using in Vitro Analysis and Molecular Dynamic Simulation of Identified Bioactive Compounds

The dipeptidyl peptidase-IV (DPP-IV) inhibitory activity of Khaya senegalensis extracts was evaluated. The DPP-IV from a rat kidney was purified to a purification fold of 2.3. Among extracts from K. senegalensis, the hexane extract had the best DPP-IV inhibitory activity, with IC₅₀ value of 1.56±0.61 μg/mL and was fractionated to eleven fractions (A-K). Fraction I had the best DPP-IV inhibition via uncompetitive pattern. GC-MS analysis of fraction I showed that the major bioactive compounds were 3-amino-3-hydroxyimino-N-phenylpropanamide (1) and 11-(2-cyclopenten-1-yl)undecanoic acid (2), with good binding affinities toward DPP-IV, based on molecular docking,. They were then subjected to molecular dynamic simulation using WEBGRO and utilizing a GROMACS system for 100 ns. The 3-amino-3-hydroxyimino-N-phenylpropanamide-DPP-IV complex was more stable and compact than the other complex. K. senegalensis contains compounds like 1 that might be used for the design of new DPP-IV inhibitors.

Mechanisms Contributing to Acquired Activated Protein C Resistance in Patients Treated with Thalidomide: A Molecular Dynamics Study

INTRODUCTION

There is a high incidence of venous thromboembolism (VTE) in patients with Multiple Myeloma (MM), however; until now, the exact mechanisms behind VTE in MM are unknown, and some of the elements that may play a significant role are the treatment with an immunomodulator (IMiD) and acquired resistance to activated protein C (APC).

OBJECTIVE

The study aims to reveal the possible mechanisms linked to the reduced antithrombotic activity of APC associated with thalidomide.

METHODS

The molecular docking approach was used to ascertain the in silico inhibitory potential of thalidomide on the APC protease domain in the architecture of the catalytic triad and its interaction with major substrate binding sites.

RESULTS

The coupling showed that the inhibitory activity of thalidomide depends on the induction of structural changes in the protease domain of APC, at the level of the Ser/His/Asp catalytic triad, as a result of a significant increase between the distances of CαAsp102 and Cα Ser195 (11.175 angstroms, increase 14.83%) and between CαSer195 and CαHis57 (9.478 angstroms, increase 13.78 %). This can result in an inefficient transfer of the proton between these residues, the other possible mechanism of inhibition, is a potential reduced binding of the substrate as a result of a direct interaction through a carbon-hydrogen bond on His57, an H-bond on Arg306, and a carbon hydrogen bond on Arg506.

CONCLUSION

We demonstrate the in silico inhibitory potential of thalidomide on APC, through two possible inhibition mechanisms, a pathophysiologically relevant finding to understand the factors that can affect the stability and functions of APC in vivo.

Cheminformatics Identification and Validation of Dipeptidyl Peptidase-IV Modulators from Shikimate Pathway-Derived Phenolic Acids towards Interventive Type-2 Diabetes Therapy

Recently, dipeptidyl peptidase-IV (DPP-IV) has become an effective target in the management of type-2 diabetes mellitus (T2D). The study aimed to determine the efficacy of shikimate pathway-derived phenolic acids as potential DPP-IV modulators in the management of T2D. The study explored in silico (molecular docking and dynamics simulations) and in vitro (DPP-IV inhibitory and kinetics assays) approaches. Molecular docking findings revealed chlorogenic acid (CA) among the examined 22 phenolic acids with the highest negative binding energy (−9.0 kcal/mol) showing a greater affinity for DPP-IV relative to the standard, Diprotin A (−6.6 kcal/mol). The result was corroborated by MD simulation where it had a higher affinity (−27.58 kcal/mol) forming a more stable complex with DPP-IV than Diprotin A (−12.68 kcal/mol). These findings were consistent with in vitro investigation where it uncompetitively inhibited DPP-IV having a lower IC₅₀ (0.3 mg/mL) compared to Diprotin A (0.5 mg/mL). While CA showed promising results as a DPP-IV inhibitor, the findings from the study highlighted the significance of medicinal plants particularly shikimate-derived phenolic compounds as potential alternatives to synthetic drugs in the effective management of T2DM. Further studies, such as derivatisation for enhanced activity and in vivo evaluation are suggested to realize its full potential in T2D therapy.

Phytochemical Classification of Medicinal Plants Used in the Treatment of Kidney Disease Based on Traditional Persian Medicine

Methods

This review was focused on studying the various secondary metabolites in model plants of Iranian herbal medicine known as treatment of kidney diseases in traditional Persian medicine textbooks including Makhzan-ol-Advieh, The Canon of Medicine, and Taghvim al-Abdan fi Tadbir al-Ensan.

Results

Secondary metabolites of 94 medical plants belonging to 42 families were reported with their scientific and family name.

Conclusion

Although herbal medicines are gaining rapid popularity among people and the pharmaceutical industry, the understandings of the phytochemical and therapeutic properties of medicinal plant are important for developing effective nephroprotective medicines. Therefore, the relationship between traditional uses and biological properties should be clearly verified through further studies.

Computational Study of Asian Propolis Compounds as Potential Anti-Type 2 Diabetes Mellitus Agents by Using Inverse Virtual Screening with the DIA-DB Web Server, Tanimoto Similarity Analysis, and Molecular Dynamic Simulation

Propolis contains a wide range of pharmacological activities because of their various bioactive compounds. The beneficial effect of propolis is interesting for treating type-2 diabetes mellitus (T2DM) owing to dysregulation of multiple metabolic processes. In this study, 275 of 658 Asian propolis compounds were evaluated as potential anti-T2DM agents using the DIA-DB web server towards 18 known anti-diabetes protein targets. More than 20% of all compounds could bind to more than five diabetes targets with high binding affinity (<−9.0 kcal/mol). Filtering with physicochemical and pharmacokinetic properties, including ADMET parameters, 12 compounds were identified as potential anti-T2DM with favorable ADMET properties. Six of those compounds, (2R)-7,4′-dihydroxy-5-methoxy-8-methylflavone; (RR)-(+)-3′-senecioylkhellactone; 2′,4′,6′-trihydroxy chalcone; alpinetin; pinobanksin-3-O-butyrate; and pinocembrin-5-methyl ether were first reported as anti-T2DM agents. We identified the significant T2DM targets of Asian propolis, namely retinol-binding protein-4 (RBP4) and aldose reductase (AKR1B1) that have important roles in insulin sensitivity and diabetes complication, respectively. Molecular dynamic simulations showed stable interaction of selected propolis compounds in the active site of RBP4 and AKR1B1. These findings suggest that Asian propolis compound may be effective for treatment of T2DM by targeting RBP4 and AKR1B1.

Terminalia catappa Extract Palliates Redox Imbalance and Inflammation in Diabetic Rats by Upregulating Nrf-2 Gene

This study aims at evaluating the ameliorative role of Terminalia catappa aqueous leaf extract (TCA) on hyperglycaemia-induced oxidative stress and inflammation in a high-fat, low dose streptozotocin-induced type 2 diabetic rat model. Experimental rats were treated orally with 400 and 800 mg/kg bw TCA daily for four weeks. Antioxidant enzyme activities, plasma glucose concentration, protein concentration, oxidative stress, and inflammation biomarkers were assayed using standard methods. Hepatic relative expressions of tumour necrosis factor-alpha (TNF-α), interleukin-six (IL-6), and nuclear factor-erythroid 2 related factor 2 (Nrf-2) were also assessed. Molecular docking and prediction of major TCA phytoconstituents' biological activity related to T2DM-induced oxidative stress were evaluated in silico. Induction of diabetes significantly (p < 0.05) reduced superoxide dismutase, glutathione-S-transferase, and peroxidase activities. Glutathione and protein stores were significantly (p < 0.05) depleted, while glucose, MDA, interleukin-six (IL-6), and tumour necrosis factor-α (TNF-α) concentrations were significantly (p < 0.05) increased. A significant (p < 0.05) upregulation of hepatic TNF-α and IL-6 expression and downregulation (p < 0.05) of Nrf-2 expression were observed during diabetes onset. TCA treatment significantly (p < 0.05) modulated systemic diabetic-induced oxidative stress and inflammation, mRNA expression dysregulation, and dysregulated macromolecule metabolism. However, only 800 mg/kg TCA treatment significantly (p < 0.05) downregulated hepatic TNF-α expression. 9-Oxabicyclo[3.3.1]nonane-2,6-diol and 1,2,3-Benzenetriol bound comparably to glibenclamide in Nrf-2, IL-6, and TNF-α binding pockets. They were predicted to be GST A and M substrate, JAK2 expression, ribulose-phosphate 3-epimerase, NADPH peroxidase, and glucose oxidase inhibitors. These results suggest that TCA ameliorates hyperglycaemia-induced oxidative stress and inflammation by activating Nrf-2 gene.

α-Amylase and dipeptidyl peptidase-4 (DPP-4) inhibitory effects of Melicope latifolia bark extracts and identification of bioactive constituents using in vitro and in silico approaches

CONTEXT

Melicope latifolia (DC.) T. G. Hartley (Rutaceae) was reported to contain various phytochemicals including coumarins, flavonoids, and acetophenones.

OBJECTIVE

This study investigates the antidiabetic and antioxidant effects of M. latifolia bark extracts, fractions, and isolated constituents.

MATERIALS AND METHODS

Melicope latifolia extracts (hexane, chloroform, and methanol), fractions, and isolated constituents with varying concentrations (0.078-10 mg/mL) were subjected to in vitro α-amylase and dipeptidyl peptidase-4 (DPP-4) inhibitory assay. Molecular docking was performed to study the binding mechanism of active compounds towards α-amylase and DPP-4 enzymes. The antioxidant activity of M. latifolia fractions and compounds were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and β-carotene bleaching assays.

RESULTS

Melicope latifolia chloroform extract showed the highest antidiabetic activity (α-amylase IC50: 1464.32 μg/mL; DPP-4 IC50: 221.58 μg/mL). Fractionation of chloroform extract yielded four major fractions (CF1-CF4) whereby CF3 showed the highest antidiabetic activity (α-amylase IC50: 397.68 μg/mL; DPP-4 IC50: 37.16 μg/mL) and resulted in β-sitosterol (1), halfordin (2), methyl p-coumarate (3), and protocatechuic acid (4). Isolation of compounds 2-4 from the species and their DPP-4 inhibitory were reported for the first time. Compound 2 showed the highest α-amylase (IC50: 197.53 μM) and β-carotene (88.48%) inhibition, and formed the highest number of molecular interactions with critical amino acid residues of α-amylase. The highest DPP-4 inhibition was exhibited by compound 3 (IC50: 911.44 μM).

DISCUSSION AND CONCLUSIONS

The in vitro and in silico analyses indicated the potential of M. latifolia as an alternative source of α-amylase and DPP-4 inhibitors. Further pharmacological studies on the compounds are recommended.

Type 2 Diabetes Mellitus Mediation by the Disruptive Activity of Environmental Toxicants on Sex Hormone Receptors: In Silico Evaluation

This study investigates the disruptive activity of environmental toxicants on sex hormone receptors mediating type 2 diabetes mellitus (T2DM). Toxicokinetics, gene target prediction, molecular docking, molecular dynamics, and gene network analysis were applied in silico techniques. From the results, permethrin, perfluorooctanoic acid, dichlorodiphenyltrichloroethane, O-phenylphenol, bisphenol A, and diethylstilbestrol were the active toxic compounds that could modulate androgen (AR) and estrogen-α and -β receptors (ER) to induce T2DM. Early growth response 1 (EGR1), estrogen receptor 1 (ESR1), and tumour protein 63 (TP63) were the major transcription factors, while mitogen-activated protein kinases (MAPK) and cyclin-dependent kinases (CDK) were the major kinases upregulated by these toxicants via interactions with intermediary proteins such as PTEN, AKT1, NfKβ1, SMAD3 and others in the gene network analysis to mediate T2DM. These toxicants pose a major challenge to public health; hence, monitoring their manufacture, use, and disposal should be enforced. This would ensure reduced interaction between people and these toxic chemicals, thereby reducing the incidence and prevalence of T2DM.

Computer-Aided Analysis of Multiple SARS-CoV-2 Therapeutic Targets: Identification of Potent Molecules from African Medicinal Plants

The COVID-19 pandemic, which started in Wuhan, China, has spread rapidly over the world with no known antiviral therapy or vaccine. Interestingly, traditional Chinese medicine helped in flattening the pandemic curve in China. In this study, molecules from African medicinal plants were analysed as potential candidates against multiple SARS-CoV-2 therapeutic targets. Sixty-five molecules from the ZINC database subset (AfroDb Natural Products) were virtually screened with some reported repurposed therapeutics against six SARS-CoV-2 and two human targets. Molecular docking, druglikeness, absorption, distribution, metabolism, excretion, and toxicity (ADMET) of the best hits were further simulated. Of the 65 compounds, only three, namely, 3-galloylcatechin, proanthocyanidin B1, and luteolin 7-galactoside found in almond (Terminalia catappa), grape (Vitis vinifera), and common verbena (Verbena officinalis), were able to bind to all eight targets better than the reported repurposed drugs. The findings suggest these molecules may play a role as therapeutic leads in tackling this pandemic due to their multitarget activity.