Alpha-Glucosidase Inhibitory Effect of Psychotria malayana Jack Leaf: A Rapid Analysis Using Infrared Fingerprinting

Comparative study of alpha-glucosidase inhibition of four Vietnamese medicinal plants Combretum quadrangulare, Dicranopteris linearis, Psychotria adenophylla, and Garcinia schomburgkiana: In vitro and in vivo studies

Four medicinal plants C. quadrangulare, D. linearis, P. adenophylla, and G. schomburgkiana growing in the South of Vietnam were investigated for their alpha-glucosidase inhibition. The crude methanol extract of C. quadrangulare was determined to be the most active extract, then was selected for further in vivo assays including antidiabetic study and toxicity. In vitro alpha-glucosidase inhibition of four medicinal plants C. quadrangulare, D. linearis, P. adenophylla, and G. schomburgkiana was screened using standard procedures. In vivo antidiabetic activity, acute toxicity and subchronical toxicity of C. quadrangulare leaves was assessed on Swiss albino mice. Swiss albino mice were induced with diabetes by intraperitoneal injection of alloxan at a dose of 150 mg/kg body weight. High-performance liquid chromatography with evaporative light scattering detector (HPLC-ELSD) were used to detect the bioactive components of C. quadrangulare leaves. All crude extracts from the studied plants showed promising alpha-glucosidase inhibition, with IC50 values ranging from 2.4 to 35.3 μg/mL. The methanol extract of C. quadrangulare leaves was determined to be the most active extract. This extract was then selected for antidiabetic assay using alloxan induced model of type 2 diabetes mellitus mice. The results indicated that the extract at a dose of 400 mg/kg can effectively decrease blood glucose levels that is comparable to that of glibenclamide 2 mg/kg. This compound showed moderate activity toward alpha-glucosidase. Therefore, our study indicated that C. quadrangulare, D. linearis, P. adenophylla, and G. schomburgkiana extract are potential materials for producing α-glucosidase inhibitor drugs.

Phytochemical Profiling and Pharmacological Evaluation of Methanolic Leaf Extract of C. digyna for Cytotoxic, Anti-inflammatory, Antioxidant, Antiarthritic, and Analgesic Activities

Caesalpinia digyna (Family: Fabaceae) is traditionally used in Ayurvedic medicine for various medicinal purposes, including as a treatment for wounds, leprosy, skin diseases, fever, diabetes, etc. Although the root and stem of this plant have a significant medicinal value, there was little research on the leaves of this plant. This study aimed to investigate the qualitative phytochemical profile and evaluate the in vitro cytotoxic, anti-inflammatory, antioxidant, and antiarthritic activities, as well as the in vivo anti-inflammatory and analgesic activities, of C. digyna leaf extract. The methanolic extract of C. digyna leaves was prepared using an ultrasonic-assisted extraction process. In vitro and in vivo anti-inflammatory activities were evaluated using the hypotonicity-induced hemolysis and carrageenan-induced paw edema methods, respectively. Additionally, the extract was assessed for in vitro DPPH (1, 1-diphenyl-2-picrylhydrazyl) free radical scavenging, antiarthritic (protein denaturation), and in vivo analgesic (acetic acid-induced writhing and tail immersion) activities. Brine shrimp lethality bioassay (BSLB) showed moderate cytotoxic activity (LC50 = 2.25 μg/mL) compared with the standard vincristine sulfate (LC50 = 1.61 μg/mL). In vitro, anti-inflammatory activity exhibited 85.13% (IC50 value = 2.51 μg/mL) inhibition of Human Red Blood Cell (HRBC) membrane lysis at a concentration of 2000 μg/mL whereas in vivo anti-inflammatory study exerted its maximum effect (p < 0.05) at 400 mg/kg bw dose. This extract also showed significant antioxidant (IC50 = 0.218 μg/mL), antiarthritic (83.61% inhibition) activity, and moderate analgesic effect (p < 0.05) in both methods. These research findings indicated that C. digyna leaves extract has potent antioxidant, analgesic, and anti-inflammatory effects which can be used as a supplementary medication for inflammatory pain-relieving factors. In future, finding the mechanism involved in these effects could have significant impact on clinical science.

Exploring the Potential of Biochar Derived from Chinese Herbal Medicine Residue for Efficient Removal of Norfloxacin

One-step carbonization was explored to prepare biochar using the residue of a traditional Chinese herbal medicine, Atropa belladonna L. (ABL), as the raw material. The resulting biochar, known as ABLB4, was evaluated for its potential as a sustainable material for norfloxacin (NOR) adsorption in water. Subsequently, a comprehensive analysis of adsorption isotherms, kinetics, and thermodynamics was conducted through batch adsorption experiments. The maximum calculated NOR adsorption capacity was 252.0 mg/g at 298 K, and the spontaneous and exothermic adsorption of NOR on ABLB4 could be better suited to a pseudo-first-order kinetic model and Langmuir model. The adsorption process observed is influenced by pore diffusion, π-π interaction, electrostatic interaction, and hydrogen bonding between ABLB4 and NOR molecules. Moreover, the utilization of response surface modeling (RSM) facilitated the optimization of the removal efficiency of NOR, yielding a maximum removal rate of 97.4% at a temperature of 304.8 K, an initial concentration of 67.1 mg/L, and a pH of 7.4. Furthermore, the biochar demonstrated favorable economic advantages, with a payback of 852.5 USD/t. More importantly, even after undergoing five cycles, ABLB4 exhibited a consistently high NOR removal rate, indicating its significant potential for application in NOR adsorption.

Bioactive-Guided Phytochemical Investigations, In Vitro and In Silico Alpha-Glucosidase Inhibition of Two Vietnamese Medicinal Plants Dicranopteris linearis and Psychotria adenophylla

Little is known about the chemical and biological profiles of Dicranopteris linearis and Psychotria adenophylla. No previous studies have investigated alpha-glucosidase inhibition using extracts from D. linearis and P. adenophylla. In this paper, bioactive-guided isolation procedures were applied to the plants D. linearis and P. adenophylla based on alpha-glucosidase inhibition. From the most active fractions, 20 compounds (DL1-DL13 and PA1-PA7) were isolated. The chemical structures were elucidated using spectroscopic data and compared with those available in the literature. These compounds were evaluated for alpha-glucosidase inhibition, while a molecular docking study was performed to elucidate the mechanisms involved. Consequently, D. linearis and P. adenophylla might serve as a good potential for developing new antidiabetic preparations.

Iron Oxide Nanoparticles Conjugated to Thiosemicarbazone Reduce the Survival of Cancer Cells by Increasing the Gene Expression of MicroRNA let-7c in Lung Cancer A549 Cells

BACKGROUND

Cancer cells have a higher demand for iron to grow and proliferate. A new complex of iron nanoparticles and thiosemicarbazones was synthesized. Confirmation tests included UV-visible, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), Fourier transform infrared (FTIR), X-ray diffraction (XRD) and zeta potential.

METHODS

MTT assay, flow cytometry and qRT-PCR were used to investigate anti-proliferative effect, amount of apoptosis and the effect of Fe3 O4 @Glu/BTSC on changes in gene expression of microRNA let-7c (let-7c), respectively. The specifications of Fe3 O4 @ Glu/BTSC were confirmed at 5 nm.

RESULTS

Fe3O4@Glu/BTSC was more effective than BTSC and Fe3 O4 on A549 cells (IC50=166.77 µg/mL) but its effect on healthy cells was smaller (CC50=189.15 µg/mL). The drug selectivity index (SI) was calculated to be 1.13. The initial apoptosis rate was 46.33% for Fe3 O4 @Glu/BTSC, 28.27% for BTSC and 26.02% for Fe3 O4 . BTSC and BTSC@Fe3 O4 inhibited the cell cycle progression in the Sub-G1 and S phases. let-7c expression was 6.9 times higher in treated cells compared to the control group. The expression rate was 2.2 with BTSC compared to the control group and 1.6 times for Fe3 O4.

CONCLUSION

Fe3 O4 @Glu/BTSC has proper anti-proliferative effects against lung cancer cells by increasing the expression of let-7c and inhibiting the cell cycle with the apoptosis activation pathway.

Preliminary Phytochemical Screening, In Vitro Antidiabetic, Antioxidant Activities, and Toxicity of Leaf Extracts of Psychotria malayana Jack

Psychotria malayana Jack belongs to the Rubiacea and is widespread in Southeast Asian countries. It is traditionally used to treat diabetes. Despite its potential medicinal use, scientific proof of this pharmacological action and the toxic effect of this plant are still lacking. Hence, this study aimed to investigate the in vitro antidiabetic and antioxidant activities, toxicity, and preliminary phytochemical screening of P. malayana leaf extracts by gas chromatography-mass spectrometry (GC-MS) after derivatization. The antidiabetic activities of different extracts of this plant were investigated through alpha-glucosidase inhibitory (AGI) and 2-NBDG glucose uptake using 3T3-L1 cell line assays, while the antioxidant activity was evaluated using DPPH and FRAP assays. Its toxicological effect was investigated using the zebrafish embryo/larvae (Danio rerio) model. The mortality, hatchability, tail-detachment, yolk size, eye size, beat per minute (BPM), and body length were taken into account to observe the teratogenicity in all zebrafish embryos exposed to methanol extract. The LC50 was determined using probit analysis. The methanol extract showed the AGI activity (IC50 = 2.71 ± 0.11 μg/mL), insulin-sensitizing activity (at a concentration of 5 µg/mL), and potent antioxidant activities (IC50 = 10.85 μg/mL and 72.53 mg AAE/g for DPPH and FRAP activity, respectively). Similarly, the water extract exhibited AGI activity (IC50 = 6.75 μg/mL), insulin-sensitizing activity at the concentration of 10 μg/mL, and antioxidant activities (IC50 = 27.12 and 33.71 μg/mL for DPPH and FRAP activity, respectively). The methanol and water extracts exhibited the LC50 value higher than their therapeutic concentration, i.e., 37.50 and 252.45 µg/mL, respectively. These results indicate that both water and methanol extracts are safe and potentially an antidiabetic agent, but the former is preferable since its therapeutic index (LC50/therapeutic concentration) is much higher than for methanol extracts. Analysis using GC-MS on derivatized methanol and water extracts of P. malayana leaves detected partial information on some constituents including palmitic acid, 1,3,5-benzenetriol, 1-monopalmitin, beta-tocopherol, 24-epicampesterol, alpha-tocopherol, and stigmast-5-ene, that could be a potential target to further investigate the antidiabetic properties of the plant. Nevertheless, isolation and identification of the bioactive compounds are required to confirm their antidiabetic activity and toxicity.

GC-MS- and NMR-Based Metabolomics and Molecular Docking Reveal the Potential Alpha-Glucosidase Inhibitors from Psychotria malayana Jack Leaves

Psychotria malayana Jack leaf, known in Indonesia as "daun salung", is traditionally used for the treatment of diabetes and other diseases. Despite its potential, the phytochemical study related to its anti-diabetic activity is still lacking. Thus, this study aimed to identify putative inhibitors of α-glucosidase, a prominent enzyme contributing to diabetes type 2 in P. malayana leaf extract using gas chromatography-mass spectrometry (GC-MS)- and nuclear magnetic resonance (NMR)-based metabolomics, and to investigate the molecular interaction between those inhibitors and the enzyme through in silico approach. Twenty samples were extracted with different solvent ratios of methanol-water (0, 25, 50, 75, and 100% v/v). All extracts were tested on the alpha-glucosidase inhibition (AGI) assay and analyzed using GC-MS and NMR. Multivariate data analysis through a partial least square (PLS) and orthogonal partial square (OPLS) models were developed in order to correlate the metabolite profile and the bioactivity leading to the annotation of the putative bioactive compounds in the plant extracts. A total of ten putative bioactive compounds were identified and some of them reported in this plant for the first time, namely 1,3,5-benzenetriol (1); palmitic acid (2); cholesta-7,9(11)-diene-3-ol (3); 1-monopalmitin (4); β-tocopherol (5); α-tocopherol (6); 24-epicampesterol (7); stigmast-5-ene (8); 4-hydroxyphenylpyruvic acid (10); and glutamine (11). For the evaluation of the potential binding modes between the inhibitors and protein, the in silico study via molecular docking was performed where the crystal structure of Saccharomyces cerevisiae isomaltase (PDB code: 3A4A) was used. Ten amino acid residues, namely ASP352, HIE351, GLN182, ARG442, ASH215, SER311, ARG213, GLH277, GLN279, and PRO312 established hydrogen bond in the docked complex, as well as hydrophobic interaction of other amino acid residues with the putative compounds. The α-glucosidase inhibitors showed moderate to high binding affinities (-5.5 to -9.4 kcal/mol) towards the active site of the enzymatic protein, where compounds 3, 5, and 8 showed higher binding affinity compared to both quercetin and control ligand.

Characterization of α-Glucosidase Inhibitors from Psychotria malayana Jack Leaves Extract Using LC-MS-Based Multivariate Data Analysis and In-Silico Molecular Docking

Psychotria malayana Jack has traditionally been used to treat diabetes. Despite its potential, the scientific proof in relation to this plant is still lacking. Thus, the present study aimed to investigate the α-glucosidase inhibitors in P.malayana leaf extracts using a metabolomics approach and to elucidate the ligand–protein interactions through in silico techniques. The plant leaves were extracted with methanol and water at five various ratios (100, 75, 50, 25 and 0% v/v; water–methanol). Each extract was tested for α-glucosidase inhibition, followed by analysis using liquid chromatography tandem to mass spectrometry. The data were further subjected to multivariate data analysis by means of an orthogonal partial least square in order to correlate the chemical profile and the bioactivity. The loading plots revealed that the m/z signals correspond to the activity of α-glucosidase inhibitors, which led to the identification of three putative bioactive compounds, namely 5′-hydroxymethyl-1′-(1, 2, 3, 9-tetrahydro-pyrrolo (2, 1-b) quinazolin-1-yl)-heptan-1′-one (1), α-terpinyl-β-glucoside (2), and machaeridiol-A (3). Molecular docking of the identified inhibitors was performed using Auto Dock Vina software against the crystal structure of Saccharomyces cerevisiae isomaltase (Protein Data Bank code: 3A4A). Four hydrogen bonds were detected in the docked complex, involving several residues, namely ASP352, ARG213, ARG442, GLU277, GLN279, HIE280, and GLU411. Compound 1, 2, and 3 showed binding affinity values of −8.3, −7.6, and −10.0 kcal/mol, respectively, which indicate the good binding ability of the compounds towards the enzyme when compared to that of quercetin, a known α-glucosidase inhibitor. The three identified compounds that showed potential binding affinity towards the enzymatic protein in molecular docking interactions could be the bioactive compounds associated with the traditional use of this plant.