Evaluation of Antioxidant Potentials and α-Amylase Inhibition of Different Fractions of Labiatae Plants Extracts: As a Model of Antidiabetic Compounds Properties

Robustanic acid as a glutaminase and Na+, K+-ATPase inhibitor from leaves of Eucalyptus globulus

This study was to compare glutaminase and Na+, K+-ATPase inhibitory activities of 20 herbal extracts and investigate the isolation, structural elucidation and those inhibitory activities of three triterpenes from the selected extract of Eucalyptus globulus Labill. Three triterpenes, ursolic acid (1), robustanic acid (2) and ursolic acid lactone (3), were identified by analyzing their NMR and MS spectral data and comparison of these with reported data. The IC50 values of 1-3 and the control compound against glutaminase, 6-diazo-5-oxo-l-norleucine (DON), were 443 μM, 334 μM, 963 μM and 134 μM, respectively. The IC50 values of 1, 2 and the control compound against Na+, K+-ATPase and ouabain, were 180 μM, 56 μM and 0.5 μM, respectively. Compounds 1 and 2 may serve as potential lead compounds for the prevention and treatment of neurodegenerative and lifestyle-related diseases by targeting glutaminase and Na+, K+-ATPase. This is the first report on glutaminase and Na+, K+-ATPase inhibitory activities of 2.

A comprehensive review of the botany, ethnopharmacology, phytochemistry, and pharmacological activities of two Iranian Rydingia species (Lamiaceae)

Rydingia michauxii and R. persica, respectively, known as Kase Gol and Goldar in Persian, belong to the family Lamiaceae and they are well known herbal medicine in Iran for the treatment of various diseases, particularly diabetes. This review aims to appraise the phytochemistry, ethnopharmacology, and pharmacological activities of Rydingia species growing in Iran and assess their potential in clinical applications. Besides, it critically evaluates existing literature and looks into the perspective for further research and utilization. All available scientific literature was consulted using the database searches involving Google Scholar, PubMed, and Web of Science applying the keyword Rydingia and its Syn; Otostegia. Only the search results that are associated with the Iranian species R. michauxii and R. persica are included in this review. α-pinene, carvacrol, caryophyllene oxide, diisooctyl phthalate, dillapiole, eugenol, hexadecanoic acid, and pentacosane are the major constituents of the essential oils of the Rydingia species. Additionally, these species produce bioactive flavonoids, phenolic acids, steroids, and terpenoids. Extracts and active compounds from Rydingia species have been reported to possess various pharmacological activities including antidiabetic, anti-inflammatory, antimalarial, antimicrobial, antioxidant, cytotoxic, and lipid-lowering properties. Based on the information available to date on the Iranian Rydingia species, it will be worth subjecting these species to further developmental work involving preclinical and clinical trials.

Effects of Salvia mirzayanii extract administration on hyperglycemia improvement in diabetic rats: The role of GLUT4, PEPCK and G6Pase genes

Diabetes is a dangerous metabolic disorder by increasing incidence in human societies worldwide. Recently, much attention has been focused on the development of hypoglycemic agents, particularly the derivatives of herbal drugs, in the treatment of diabetes. This research aimed to study the anti-diabetic effect of Salvia mirzayanii in the diabetic rat models. First, the plant material was extracted from the leaves, and orally administered to the rats. After treating the animals with the aqueous extract of S. mirzayanii at a dose of 600 mg/kg, animal body weight for 12 weeks, fasting blood glucose, oral glucose tolerance test (OGTT), and body weight changes were examined. To analyze the anti-diabetic function of S. mirzayanii, we measured the expression of glucose transporter-4 (GLUT4), phosphoenolpyruvate carboxykinase (PEPCK), and glucose 6-phosphatase (G6Pase) genes in healthy and streptozotocin (STZ)-diabetic rats. The expression levels of the genes of interest in muscle and liver tissues were determined using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry (IHC). There were no significant differences in fasting blood glucose and OGTT between normal control (NC) group and the diabetic control (DC) group treated with S. mirzayanii. In contrast, there was a significant difference with the untreated DC (P < 0.05). The treatment of diabetic rats with S. mirzayanii significantly increased the expression of GLUT4 in the muscle and decreased the expression levels of PEPCK and G6Pase in the liver compared to the DC group (P < 0.05). These findings clearly show that S. mirzayanii can improve hyperglycemia by increasing the GLUT4 expression, and inhibiting the gluconeogenesis pathway in the liver. In general, the obtained results provided a new insight into the efficacy of S. mirzayanii aqueous extract as an anti-diabetic herbal medicine.

Assessment of polystyrene nano plastics effect on human salivary α-amylase structural alteration: Insights from an in vitro and in silico study

The study found that the enzyme activity of human salivary α-amylase (α-AHS) was competitively inhibited by nanoplastic polystyrene (PS-NPs), with a half-inhibitory concentration (IC50) of 92 μg/mL, while the maximum reaction rate (Vmax) remained unchanged at 909 μg/mL•min. An increase in the concentration of PS-NPs led to a quenching of α-AHS fluorescence with a slight red shift, indicating a static mechanism. The binding constant (Ka) and quenching constant (Kq) were calculated to be 2.92 × 1011 M-1 and 1.078 × 1019 M-1• S-1 respectively, with a hill coefficient (n) close to one and an apparent binding equilibrium constant (KA) of 1.54 × 1011 M-1. Molecular docking results suggested that the interaction between α-AHS and PS-NPs involved π-anion interactions between the active site Asp197, Asp300 residues, and van der Waals force interactions affecting the Tyr, Trp, and other residues. Fourier transform infrared (FT-IR) and circular dichroism (CD) analyses revealed conformational changes in α-AHS, including a loss of secondary structure α-helix and β-sheet. The study concludes that the interaction between α-AHS and PS-NPs leads to structural and functional changes in α-AHS, potentially impacting human health. This research provides a foundation for further toxicological analysis of MPs/NPs in the human digestive system.

Multimode Assessment of Commercial Polyherbal Formulation: an In Vitro and In Silico Approach

Antidiabetic polyherbal formulations (APH) are used in management of diabetes mellitus (DM). High glucose levels in DM are related to oxidative stress leading to its associated complications. Therefore, assessing antioxidant activity of various APH might unveil an antioxidant-rich formulation for management of DM and its associated complications. Subsequently selecting an antioxidant assessment method is a challenging aspect, considering various in vitro assays working with diverse mechanism of action. Therefore, present study aims to validate the sensitivity/capacity of different antioxidant assay, thereby assessing the antioxidant potential of 9-APH. Obtained results revealed the ABTS·⁺ values were higher compared to DPPH⁺ assay. I-9-HAE (DPPH⁺: IC₅₀ 53.31 µg/ml), NK-HAE (ABTS·⁺: IC₅₀ 2.71 µg/ml), and MN-HAE (FRAP and TAC) exhibited highest antioxidant capacity. A significant correlation was obtained between TPC-DPPH⁺ (r²: 0.8187****). Furthermore, three APH with better antiradical potential was chosen for various in vitro and in silico method, for validating scientific antidiabetic propensities. Among the tested extracts, I-9-HAE (α-amylase inhibition: IC₅₀ 831.84 µg/ml) and MN-HAE (α-glucosidase inhibition: IC₅₀ 558.64 µg/ml and antiglycation: IC₅₀ 883.74 µg/ml) have showed highest antihyperglycemic and antiglycation properties. Finally, the secondary-metabolites of selected APH were screened through literature search, Lipinski rule, ADMET, and ProTox-II. Subsequently, in molecular docking for the selected 9 secondary metabolites, highest binding affinity was observed in apigenin-7-glucuronide for DPPiv (- 9.6), GLP-1 (- 8.8), NADPH (- 8.7), and HSA (- 9.4). Thus, obtained result proposes synergistic interaction with high antioxidant potential of the selected 3-APH and can be considered an alternative for management of DM, where multiple secondary metabolites exert holistic biological effects. Furthermore, our study also provides data on sensitivity/capacity of different in vitro antioxidant assays.

An investigationof the inhibitory effects of dichloromethane and methanol extracts of Salvia macilenta, Salvia officinalis, Salvia santolinifola and Salvia mirzayanii on diabetes marker enzymes, an approach for the treatment diabetes

Background

Diabetes mellitus is a type of metabolic disease characterized by elevated blood sugar. The main strategy for its treatment is to inhibit carbohydrate-hydrolyzing enzymes, including α-amylase and α-glucosidase. The aim of the present study was to evaluate the efficacy of Salvia extracts in inhibiting diabetes marker enzymes.

Materials and methods

This experimental study was performed in vitro. The studied plants included Salvia mirzayanii, Salvia macilenta, Salvia officinalis and Salvia santolinifola and inhibitory effects of their methanolic and dichloromethane extracts were investigated. After calculating the percentage of α-amylase inhibition and IC50 of the extracts, Km and Vmax were also determined using prism7.Statistical analysis was performed employing with Graph Pad instat3 software.

Results

The results here in revealed that methanol extracts of Salvia santolinifola (with IC50 = 54.72 ± 9.6 μg / ml) and Salvia officinalis with (IC50 = 54.87 ± 5.7 μg / ml) and dichloromethane extract of Salvia officinalis with (IC50 = 71.20 ± 14.3 μg / ml) had the greatest inhibitory effect on α-amylase comparing to acarbose with (IC50 = 42.94 ± 3.8 μg / ml) as a standard. Tukey test results showed that there is a significant difference between IC50 of acarbose comparing to methanol extract of Salvia mirzayanii and dichloromethane extracts of Salvia mirzayanii and Salvia santolinifola with P value ˂0.001 in α-amylase inhibition.

Conclusion

The extracts had significant inhibitory effects on α-amylase inhibition. Among the extracts of the studied species, methanol extract of Salvia santolinifola demonstrated the greatest inhibitory effect on α-amylase.

Phytochemical screening, antiobesity, antidiabetic and antimicrobial assessments of Orobanche aegyptiaca from Palestine

Background

Microbial resistance, diabetes mellitus, and obesity are global health care problems that have posed a serious threat to both human and environmental ecosystems. The goals of the present investigations are to investigate the phytoconstituents, antilipase, anti-α-amylase, and antimicrobial activity of Orobanche aegyptiaca Pers. (OA) from Palestine.

Methods

Identification of the phytoconstituents of OA plant petroleum ether, methylene chloride, chloroform, acetone, and methanol extracts were conducted using pharmacopeia’s methods, while porcine pancreatic lipase and α–amylase inhibitory activities were examined using p-nitrophenyl butyrate and 3,5-dinitro salicylic acid methods, respectively. Moreover, the antimicrobial activity was evaluated utilizing broth microdilution assay against eight bacterial and fungal strains.

Results

The phytochemical screening results showed that the methanol extract of the OA plant is rich in phytochemical components, also this extract has powerful antilipase potential with an IC₅₀ value of 19.49 ± 0.16 μg/ml comparing with the positive control (Orlistat) which has antilipase activity with IC₅₀ value of 12.3 ± 0.35 μg/ml. Moreover, the methanol and chloroform extracts have powerful α-amylase inhibitory activity with IC₅₀ values of 28.18 ± 0.22 and 28.18 ± 1.22 μg/ml, respectively comparing with Acarbose which has α-amylase inhibitory activity with IC₅₀ dose of 26.3.18 ± 0.28 μg/ml. The antibacterial results showed that the methylene chloride extract exhibited the highest antibacterial activity among the other OA plant extracts with a MIC value of 0.78 mg/ml against S. aureus, while, the methylene chloride, petroleum ether, and chloroform extracts of the OA plant showed potential antifungal activity against C. albicans strains with MIC value of 0.78 mg/ml.

Conclusion

The OA methanol and chloroform extracts could be excellent candidates as antilipase and anti-α-amylase bioactive materials. In addition, methylene chloride, petroleum ether, and chloroform extracts could be potential natural antimicrobial products.

Exploration of Diosmin to Control Diabetes and Its Complications-an In Vitro and In Silico Approach

BACKGROUND

Diosmin is a flavonoid obtained from the citrus fruits of the plants. Diosmin has blood lipid lowering activities, antioxidant activity, enhances venous tone and microcirculation, protects capillaries, mainly by reducing systemic oxidative stress.

OBJECTIVE

The present study demonstrates the potential of Diosmin against the enzymes aldose reductase, α-glucosidase, and α-amylase involved in diabetes and its complications by in vitro evaluation and reverse molecular docking studies.

METHODS

The assay of aldose reductase was performed by using NADPH as starting material and DL-Glyceraldehyde as a substrate. DNS method was used for alpha amylase inhibition and in alpha glucosidase inhibitory activity p-nitrophenyl glucopyranoside (pNPG) was used as substrate. The reverse molecular docking studies was performed by using Molegro software (MVD) with grid resolution of 30 Å.

RESULTS

Diosmin shows potent inhibitory effect against aldose reductase (IC50:333.88±0.04 μg/mL), α-glucosidase (IC50:410.3±0.01 μg/mL) and α-amylase (IC50: 404.22±0.02 μg/mL) respectively. The standard drugs shows moderate inhibitory activity for enzymes. The MolDock Score of Diosmin was -224.127 against aldose reductase, -168.17 against α-glucosidase and - 176.013 against α-amylase respectively, which was much higher than standard drugs.

CONCLUSION

From the result it was concluded that diosmin was a potentially inhibitor of aldose reductase, alpha amylase and alpha glucosidase enzymes then the standard drugs and it will be helpful in the management of diabetes and its complications. This will also be benevolent to decrease the socio economical burden on the middle class family of the society.

Influence of Kersting's (Kerstingiella geocarpa) groundnut proteins on the physicochemical, bioactive properties and storage stability of orange juice

Sweet orange ranks as one of the most acceptable fruit juices across the globe as it offers a healthy choice and pleasant taste to a wide spectrum of consumers. This makes it a promising vehicle for conveying functional ingredients into the human body. The present study was designed to produce functional orange juice by incorporating Kersting's groundnut proteins (isolate and hydrolysates) at different proportions (0.6, 0.8 and 1.0 w/v) into freshly produced sweet orange juice. The sample formulations were further analysed for changes in their physicochemical (pH, titratable acidity, total soluble sugars, ascorbic acid and total phenol content), sensory (appearance, colour, flavour, mouthfeel and overall acceptability), antioxidant (radical scavenging, metal chelating, ferric ion-reducing abilities, DPPH, total antioxidant) and antidiabetic (inhibition of α-amylase and α-glucosidase enzyme activities) properties as well as their storage stability over a 90-day storage period. The functional orange juice exhibited an improved physicochemical, antioxidant, antidiabetic and shelf life properties based on the respective protein concentrations used over the 90-day study period while the sample with the lowest proportion (0.6%) of functional ingredient had the highest sensory acceptability. Hence, the study concluded that Kersting's groundnut proteins could find useful applications in the formulation of functional orange juice.

Signaling, metabolism, and cancer: An important relationship for therapeutic intervention

In cancerous cells, significant changes occur in the activity of signaling pathways affecting a wide range of cellular activities ranging from growth and proliferation to apoptosis, invasiveness, and metastasis. Extensive changes also happen with respect to the metabolism of a cancerous cell encompassing a wide range of functions that include: nutrient acquisition, biosynthesis of macromolecules, and energy generation. These changes are important and some therapeutic approaches for treating cancers have focused on targeting the metabolism of cancerous cells. Oncogenes and tumor suppressor genes have a significant effect on the metabolism of cells. There appears to be a close interaction between metabolism and the signaling pathways in a cancerous cell, in which the interaction provides the metabolic needs of a cancerous cell for uncontrolled proliferation, resistance to apoptosis, and metastasis. In this review, we have reviewed the latest findings in this regard and briefly review the most recent research findings regarding targeting the metabolism of cancer cells as a therapeutic approach for treatment of cancer.

Middle East Medicinal Plants in the Treatment of Diabetes: A Review

Diabetes is a global health problem, and the number of diabetic patients is in continuous rise. Conventional antidiabetic therapies are associated with high costs and limited efficiency. The use of traditional medicine and plant extracts to treat diabetes is gaining high popularity in many countries. Countries in the Middle East region have a long history of using herbal medicine to treat different diseases, including diabetes. In this review, we compiled and summarized all the in vivo and in vitro studies conducted for plants with potential antidiabetic activity in the Middle East region. Plants of the Asteraceae and Lamiaceae families are the most investigated. It is hoped that this review will contribute scientifically to evidence the ethnobotanical use of medicinal plants as antidiabetic agents. Work has to be done to define tagetes, mechanism of action and the compound responsible for activity. In addition, safety and pharmacokinetic parameters should be investigated.

Bioassay-guided identification of α-amylase inhibitors in herbal extracts

This study focuses on the health benefits of several fresh herbs that are commonly used in the Mediterranean diet. Antioxidant activity, phytosterol content and α-amylase inhibitory activity of fresh basil, lavender, oregano, rosemary, sage, and thyme are analyzed and compared. High-performance thin-layer chromatography (HPTLC) combined with effect directed analysis was used to detect and quantify biological active compounds on chromatograms. The highest antioxidant activity was measured in the extract from oregano leaf, while the highest terpenoid content was in basil leaf extract. All extracts except lavender leaf and lavender flower extracts showed α-amylase inhibition. The same compound at hR_F = 68 in basil, oregano, rosemary, sage, and thyme extracts was responsible for α-amylase inhibition. Combined with effect-directed assays and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, hyphenated HPTLC allowed a fast characterization of the active compound. ATR spectral analysis of this band tentatively identified oleanolic acid (or its derivative) to be responsible for the α-amylase inhibition.

In vitro Angiotesin-1-converting enzyme, α-amylase and α-glucosidase inhibitory and antioxidant activities of Luffa cylindrical (L.) M. Roem seed protein hydrolysate

In recent times, researchers have explored food derived peptides to circumvent the side effects of synthetic drugs. This study therefore examined the amino acid constituents, in vitro antioxidant activities, angiotensin-1-converting enzyme (ACE), α-glucosidase and α-amylase inhibition kinetics of protein hydrolysate obtained from the seed of Luffa cylindrica. The peptide yield by pepsin (16.93 ± 0.28%) and trypsin (13.20 ± 1.02%) were significantly lower than that of Alcalase (34.04 ± 1.96%). Alcalase hydrolysate however displayed the highest ferric reducing antioxidant capacity (FRAC), 1,1-diphenyl-2-picrylhydrazyl (DPPH) and H₂O₂ scavenging activities (0.63%, 85.88% and 41.69% respectively), while the highest superoxide scavenging activity was shown by peptic hydrolysate (57.89%). The ACE inhibition by the hydrolysates with IC₅₀ of 0.32-0.93 mg/mL, increased as the concentration of the peptic hydrolysate increased with the highest ACE-inhibitory activity (74.99 ± 0.43%) at 1.2 mg/mL of peptic hydrolysate. Tryptic and Alcalase hydrloysates exhibited a strong α-amylase inhibition having 27.96 ± 0.06% and 36.36 ± 0.71% inhibitory capacity respectively with IC₅₀ of 1.02-3.31 mg/mL. Alcalase hydrolysates demonstrated the strongest inhibition (65.81 ± 1.95%), followed by tryptic hydrolysates (54.53 ± 0.52%) in a concentration-dependent inhibition of α-glucosidase (IC_{50 ,} 0.48-0.80 mg/mL). Kinetic analysis showed that ACE-inhibition by different concentrations of Alcalase, pepsin and trypsin hydrolysates is uncompetitive, mixed-type and non-competitive respectively. α-Amylase was non-competitively inhibited while α-glucosidase was un-competitively inhibited by all the hydrolysates. The total amino acid concentration for Alcalase, trypsin and pepsin hydrolysates was 53.51g/100g, 75.40g/100g and 85.42g/100g of Luffa cylindrica seed protein hydrolysate respectively, with glutamate being the most concentrated essential amino acid in all the three hydrolysates. From these results, it can be deduced that Luffa cylindrica seed Alcalase and tryptic protein hydrolysates may play critical and indispensible role as bio-tools in diabetes and hypertension treatment.

Methanol-Extract/Fractions of Dacryodes edulis Leaves Ameliorate Hyperglycemia and Associated Oxidative Stress in Streptozotocin-Induced Diabetic Wistar Rats

The present study evaluated the antidiabetic and antioxidant potential of the methanolic extract/solvent fractions of the leaves of Dacryodes edulis using a streptozotocin (STZ)-induced diabetic Albino Wistar rat model. The fasting blood glucose/insulin levels and inhibition of α-amylase and α-glucosidase were determined. Antioxidant activity was assessed in vitro by 2,2-diphenyl-1-picrylhydrazyl, hydroxyl, superoxide scavenging, reducing power, and total antioxidant capacity assays and in vivo by monitoring catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) activities and reduced glutathione (GSH) and malondialdehyde (MDA) levels. The aqueous-methanol fraction exhibited the highest and significant (P < .05) reduction in fasting blood glucose (FBG; 54.03%) with a concomitant inhibition of α-amylase and α-glucosidase activities. The ethyl acetate fraction also exhibited a significant (P < .05) reduction in FBG and an increase in insulin levels in the treated diabetic Wistar rats. A significantly (P < .05) higher reducing power and radical scavenging activity was observed in the aqueous-methanol and ethyl acetate fractions. The aqueous-methanol and ethyl acetate fractions also significantly (P < .05) reversed the alterations in oxidative stress markers (GSH, MDA, CAT, and SOD) observed in the diabetic control group. In conclusion, the study demonstrated that the methanol extract of Dacryodes edulis ameliorates hyperglycemia and the associated oxidative stress in STZ-induced diabetic Wistar rats. These observed activities are largely due to the compounds that partitions into the aqueous-methanol (55:45) solvent fraction. This provides scientific evidence for the use of this plant extract in folk medicine and also a baseline data for its further characterization. Further work should be carried out to characterize the aqueous-methanol solvent fractions for the active compounds.